2 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
3
EURASIAN PHYSICAL TECHNICAL JOURNAL
ISSN 1811-1165 Volume 8 No 1(15) 2011
Quarterly journal of the International
Higher Education Academy of Sciences
1st issue ndash March 2004
Journal Founders
THE INTERNATIONAL HIGHER EDUCATION ACADEMY OF SCIENCES
ХАЛЫҚАРАЛЫҚ ЖОҒАРҒЫ БІЛІМ АКАДЕМИЯСЫ
KARAGANDA STATE UNIVERSITY NAMED AFTER EABUKETOV
ЕАБӨКЕТОВ АТЫНДАҒЫ ҚАРАҒАНДЫ МЕМЛЕКЕТТІК УНИВЕРСИТЕТІ
INSTITUTE OF TECHNICAL PHYSICS AND PROBLEMS OF ECOLOGY
ТЕХНИКАЛЫҚ ФИЗИКА ЖӘНЕ ЭКОЛОГИЯ МӘСЕЛЕЛЕРІ ИНСТИТУТЫ
Contact information
Editorial board of EPhTJ (r221) Institute of Technical Physics and Problems of Ecology Karaganda State University named after EABuketov
Universitetskaya Str28 Karaganda Kazakhstan 100026 Subscription index 75240
Tel +7(7212)77-04-03 Fax +7(7212)77-03-84
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Printed in the Publishing House of the KarSU named after EABuketov
ЕА Бөкетов атындағы ҚарМУ баспасының
баспаханасында басылып шықты
EDITOR EK Kubeev Karaganda State University named after EABuketov Karaganda Kazakhstan
ASSOCIATE EDITOR SESakipova Karaganda State University named after EABuketov Karaganda Kazakhstan
EDITORIAL BOARD AKAringazin Institute for Basic Research Eurasian National University named after LNGumilev Astana Kazakhstan KSBaktybekov Eurasian National University named after LNGumilev Astana Kazakhstan GNBorzdov Belarusian State University Minsk Belarus SDzhumanov Institute of Nuclear Physics Tashkent Uzbekistan KShChokin Institute of Physics and Technology Almaty Kazakhstan JDueck Erlangen-Nuernberg University Erlangen Germany EYaEpik Institute of Engineering Thermophysics National Sciences Academy Kiev Ukraine MMKidibaev Issyk-kul State University named after KTynystanov Karakol Kyrgyzstan SEKumekov Kazakh State National Technical University named after KSatbaev Almaty Kazakhstan AIKupchishin Al-Farabi Kazakh National State University Almaty Kazakhstan KKusaiynov Karaganda State University named after EABuketov Karaganda Kazakhstan JJMiau Department of Aeronautics and Astronautics National Cheng Kung University Tainan Taiwan CPedrini University Claude Bernard Lyon I France FKRahimov Tajik State National University Dushanbe Tajikistan AOSaulebekov Karaganda State University named after EABuketov Karaganda Kazakhstan ASlanciauskas Lithuanian Energy Institute Kaunas Lithuania GVSakovich Institute of Chemical Problems and Power Technologies Byisk Russia SJChoi Korea University of Technology and Education Seoul Southern Korea ERShrager Tomsk State University Tomsk Russia TSzalay Budapest University of Technology and Economics Budapest Hungary ASTsybin Moscow Engineering Physics Institute Moscow Russia ZZhZhanabaev Al-Farabi Kazakh National State University Almaty Kazakhstan
CONSULTANTS OF TRANSLATION KEAkhmerova SNAssylbekova AA Ganyukova Karaganda State University named after EABuketov Karaganda Kazakhstan
TECHNICAL SECRETARY MPMarkova Karaganda State University named after EABuketov Karaganda Kazakhstan
copy Karaganda State University 2011 copy Қарағанды мемлекеттік университеті 2011 Registered by the Ministry of Culture Information and Public Adjustment of the Republic of Kazakhstan
Қазақстан Республикасы мәдениет ақпарат және қоғамдық келісім министрлігімен тіркелді Registration Certificate No 4382-Zh from November 7 2003
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Eurasian Physical Technical Journal
Vol 8 No 1(15) 2011
CONTENTS
CONDENSED MATTER PHYSICS
Time-Resolved Luminescent Spectrometry Of Zink Selenide Crystals
VI Oleshko SS Vilrsquochinskaya SG Gorina
3
Superficial Tension Of Pure Metals VM Jurov
10
About Luminescent Properties Of Monocrystals Of The Difficult Sulfates Activated By Thallium
K S Baktybekov MK Myrzakhmet M Nikl V Jerry K Bekmyrza
15
HEAT PHYSICS HYDRODYNAMICS ENERGETIC
Gravitational Convection In Gas System Ar ndash N2
IV Poyarkov
19
Nonlinear Fractals And Exciton Formations In Nanostructured Semiconductors
ZZh Zhanabayev TYu Grevtseva
23
Hydrodynamics Of Hydrocyclone With Built-In Water Injector
L Minkov M Farghaly J Dueck
29
DEVICES AND METHODS OF EXPERIMENT
The Results Of ldquoVibration-Seismic-Module-Solid Massif-Disturbancerdquo System Simulation
Modeling
Y M Smirnov BM Kenzhin MA Zhurunova
42
Analysis Of The Procedure Lcas In Transport Networks Ngsdh
DM Zakiev GPAmochaeva RA Mursalin
49
Research Of Influence Of Speech Codecs On Transmission Quality Of The Digital Signal
ZhK Ishchanova GP Amochaeva AK Tussupbekova
56
2
3
UDC 53924 53921
TIME-RESOLVED LUMINESCENT SPECTROMETRY OF ZINK SELENIDE
CRYSTALS
VI Oleshko SS Vilrsquochinskaya SG Gorina
National Research Tomsk Polytechnic University 634050 Russia Tomsk Lenin Avenue 30 svetlanagorinamailru
The spectral and kinetic characteristics of pulse cathodoluminescence of undoped ZnSe single-crystals
grown by sublimation from the vapor phase (Davydov-Markov method) and by flux growth (Bridgman
method) have been measured Three groups of bands were found in the spectra of radiative recombination of
zinc selenide exciton edge emission and bands due to the recombination of carriers in deep centers The
spectral-kinetic characteristics of the edge emission in ZnSe crystals with different previous history have
been studied It was found that the number of edge emission series the ratio of their intensities and spectral
position are to be determined by the previous history of crystals It is shown that the total intensity of the
edge emission reduces more than tenfold with the temperature increase in the range of 15 - 80 K The results
obtained show that the properties of the edge emission can be well described by the model of donor-acceptor
pairs
Keywords cathodoluminescence sublimation single-crystals edge emission radiative recombination
Introduction
AIIB
VI semiconductors are considered to be promising materials in optoelectronics and infrared
technology The first information about the research of luminescent characteristics of ZnSe at low
temperatures dates back to 1960 It was reported about the edge emission observed as a large
number of sharp lines in ZnSe photoluminescence spectra in the temperature range 42 - 77 K [1 2]
and the impurity radiation observed as broad bands in longer wavelength region [3] However so
far there is no single opinion concerning the mechanism of edge emission in ZnSe crystals In [4]
the centers of edge emission are considered to be due to the isolated oxygen OSe-centers and distant
OSe-OSe - pairs The authors of [5] believe that this is due to the recombination of donor-acceptor
pairs The nature of the impurity luminescence also causes heated debate among researchers
The development of luminescence centers models is constrained by the lack of information (or
its complete absence) on the kinetic parameters of the observed luminescence bands radiation and
their dependence on the experimental conditions The purpose of the research is to investigate the
spectral and kinetic characteristics of pulse luminescence in ZnSe crystals with different previous
history grown by different technologies in irradiation by a pulsed high-current electron beam of
nanosecond duration
The practical significance of the work is defined by the possibility to use the findings for
creating the model of energy transitions in ZnSe which promotes the development of new optical
devices with electron excitation
Experimental
To study the luminescence of ZnSe was used the technique of pulse luminescent spectrometry
with nanosecond time resolution [6] was used This method has several advantages compared to
stationary methods of research Additional analytical capabilities of luminescent spectral analysis
by using a pulsed spectrometer are provided by the use of nanosecond high-current electron beams
as well as the possibility of extracting useful information about the luminescence centers from the
kinetic characteristics of luminescence decay The spectrum and its evolution over the time after the
excitation pulse are defined by the technology of the crystal growth
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation source was a pulsed electron accelerator with the parameters average electron
energy in the beam of ~ 025 MeV the current pulse duration FWHM of ~ 15 ns The test sample
was set at an angle of 45deg to the direction of the electron flow The samples were cooled by the
industrial microcryogenic system MSMR-110N-3220 which allows cooling a sample down to 125
K without liquid helium or nitrogen Pulse cathodoluminescence of zinc selenide crystals was
investigated in the spectral range 440 - 750 nm at 15 and 300 K The glow of the sample was
projected by a lens onto the entrance slit of the monochromator MDR-204 and detected by PMT-84
and the storage oscilloscope Tektronix TDS 2022 The time resolution of the recording channel was
~ 15 ns the spectral resolution made ~ 00015 eV The luminescence spectra were normalized by
taking into account the spectral sensitivity of the spectrometer optical path The electron beam
energy was measured by radiation-chemical method
Intentionally undoped ZnSe single-crystals with different previous history were used as
samples Samples 1 and 2 were obtained by Davydov-Markov method sample 3 was grown
by Bridgman method
Results and Discussion
The absorption edge of the crystals may provide important information on the band gap and
defects in a crystal lattice The absorption spectra of the samples were measured by a
spectrophotometer SF-256 at 300 K As can be seen from Fig 1 the absorption edge of the ZnSe
crystals is shifted to longer wavelengths compared to fundamental absorption edge of pure ZnSe
which position is defined by free exciton FEZnSe (λ ~ 460 nm at 300 K)
Fig1 Absorption spectra of ZnSe crystals at 300 K
The absorption spectra of the samples 1 and 2 are close to each other this may be caused
by the same nature of the defects responsible for the absorption edge in these crystals The spectrum
of the sample 3 is shifted to longer wavelengths by ~ 10 nm compared to the absorption spectra
of the samples 1 and 2 and has no sharp edges indicating high concentration of both shallow
and deep levels in the band gap of the crystal
The spectral and kinetic characteristics of the pulse cathodoluminescence in ZnSe was
measured at the electron beam energy density 002 Jcm2 (G = 10
26 cm
-3 s
-1) In the luminescence
spectra of the samples 1 and 2 measured at 300 K we observed one band with the maxima at λ
= 470 nm and λ = 468 nm respectively Its decay time was τ le 15 ns The spectrum of the sample
3 is distinguished by the band in the long wavelength region with the peak at λ = 550 nm The
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
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JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
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3
EURASIAN PHYSICAL TECHNICAL JOURNAL
ISSN 1811-1165 Volume 8 No 1(15) 2011
Quarterly journal of the International
Higher Education Academy of Sciences
1st issue ndash March 2004
Journal Founders
THE INTERNATIONAL HIGHER EDUCATION ACADEMY OF SCIENCES
ХАЛЫҚАРАЛЫҚ ЖОҒАРҒЫ БІЛІМ АКАДЕМИЯСЫ
KARAGANDA STATE UNIVERSITY NAMED AFTER EABUKETOV
ЕАБӨКЕТОВ АТЫНДАҒЫ ҚАРАҒАНДЫ МЕМЛЕКЕТТІК УНИВЕРСИТЕТІ
INSTITUTE OF TECHNICAL PHYSICS AND PROBLEMS OF ECOLOGY
ТЕХНИКАЛЫҚ ФИЗИКА ЖӘНЕ ЭКОЛОГИЯ МӘСЕЛЕЛЕРІ ИНСТИТУТЫ
Contact information
Editorial board of EPhTJ (r221) Institute of Technical Physics and Problems of Ecology Karaganda State University named after EABuketov
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ЕА Бөкетов атындағы ҚарМУ баспасының
баспаханасында басылып шықты
EDITOR EK Kubeev Karaganda State University named after EABuketov Karaganda Kazakhstan
ASSOCIATE EDITOR SESakipova Karaganda State University named after EABuketov Karaganda Kazakhstan
EDITORIAL BOARD AKAringazin Institute for Basic Research Eurasian National University named after LNGumilev Astana Kazakhstan KSBaktybekov Eurasian National University named after LNGumilev Astana Kazakhstan GNBorzdov Belarusian State University Minsk Belarus SDzhumanov Institute of Nuclear Physics Tashkent Uzbekistan KShChokin Institute of Physics and Technology Almaty Kazakhstan JDueck Erlangen-Nuernberg University Erlangen Germany EYaEpik Institute of Engineering Thermophysics National Sciences Academy Kiev Ukraine MMKidibaev Issyk-kul State University named after KTynystanov Karakol Kyrgyzstan SEKumekov Kazakh State National Technical University named after KSatbaev Almaty Kazakhstan AIKupchishin Al-Farabi Kazakh National State University Almaty Kazakhstan KKusaiynov Karaganda State University named after EABuketov Karaganda Kazakhstan JJMiau Department of Aeronautics and Astronautics National Cheng Kung University Tainan Taiwan CPedrini University Claude Bernard Lyon I France FKRahimov Tajik State National University Dushanbe Tajikistan AOSaulebekov Karaganda State University named after EABuketov Karaganda Kazakhstan ASlanciauskas Lithuanian Energy Institute Kaunas Lithuania GVSakovich Institute of Chemical Problems and Power Technologies Byisk Russia SJChoi Korea University of Technology and Education Seoul Southern Korea ERShrager Tomsk State University Tomsk Russia TSzalay Budapest University of Technology and Economics Budapest Hungary ASTsybin Moscow Engineering Physics Institute Moscow Russia ZZhZhanabaev Al-Farabi Kazakh National State University Almaty Kazakhstan
CONSULTANTS OF TRANSLATION KEAkhmerova SNAssylbekova AA Ganyukova Karaganda State University named after EABuketov Karaganda Kazakhstan
TECHNICAL SECRETARY MPMarkova Karaganda State University named after EABuketov Karaganda Kazakhstan
copy Karaganda State University 2011 copy Қарағанды мемлекеттік университеті 2011 Registered by the Ministry of Culture Information and Public Adjustment of the Republic of Kazakhstan
Қазақстан Республикасы мәдениет ақпарат және қоғамдық келісім министрлігімен тіркелді Registration Certificate No 4382-Zh from November 7 2003
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Eurasian Physical Technical Journal
Vol 8 No 1(15) 2011
CONTENTS
CONDENSED MATTER PHYSICS
Time-Resolved Luminescent Spectrometry Of Zink Selenide Crystals
VI Oleshko SS Vilrsquochinskaya SG Gorina
3
Superficial Tension Of Pure Metals VM Jurov
10
About Luminescent Properties Of Monocrystals Of The Difficult Sulfates Activated By Thallium
K S Baktybekov MK Myrzakhmet M Nikl V Jerry K Bekmyrza
15
HEAT PHYSICS HYDRODYNAMICS ENERGETIC
Gravitational Convection In Gas System Ar ndash N2
IV Poyarkov
19
Nonlinear Fractals And Exciton Formations In Nanostructured Semiconductors
ZZh Zhanabayev TYu Grevtseva
23
Hydrodynamics Of Hydrocyclone With Built-In Water Injector
L Minkov M Farghaly J Dueck
29
DEVICES AND METHODS OF EXPERIMENT
The Results Of ldquoVibration-Seismic-Module-Solid Massif-Disturbancerdquo System Simulation
Modeling
Y M Smirnov BM Kenzhin MA Zhurunova
42
Analysis Of The Procedure Lcas In Transport Networks Ngsdh
DM Zakiev GPAmochaeva RA Mursalin
49
Research Of Influence Of Speech Codecs On Transmission Quality Of The Digital Signal
ZhK Ishchanova GP Amochaeva AK Tussupbekova
56
2
3
UDC 53924 53921
TIME-RESOLVED LUMINESCENT SPECTROMETRY OF ZINK SELENIDE
CRYSTALS
VI Oleshko SS Vilrsquochinskaya SG Gorina
National Research Tomsk Polytechnic University 634050 Russia Tomsk Lenin Avenue 30 svetlanagorinamailru
The spectral and kinetic characteristics of pulse cathodoluminescence of undoped ZnSe single-crystals
grown by sublimation from the vapor phase (Davydov-Markov method) and by flux growth (Bridgman
method) have been measured Three groups of bands were found in the spectra of radiative recombination of
zinc selenide exciton edge emission and bands due to the recombination of carriers in deep centers The
spectral-kinetic characteristics of the edge emission in ZnSe crystals with different previous history have
been studied It was found that the number of edge emission series the ratio of their intensities and spectral
position are to be determined by the previous history of crystals It is shown that the total intensity of the
edge emission reduces more than tenfold with the temperature increase in the range of 15 - 80 K The results
obtained show that the properties of the edge emission can be well described by the model of donor-acceptor
pairs
Keywords cathodoluminescence sublimation single-crystals edge emission radiative recombination
Introduction
AIIB
VI semiconductors are considered to be promising materials in optoelectronics and infrared
technology The first information about the research of luminescent characteristics of ZnSe at low
temperatures dates back to 1960 It was reported about the edge emission observed as a large
number of sharp lines in ZnSe photoluminescence spectra in the temperature range 42 - 77 K [1 2]
and the impurity radiation observed as broad bands in longer wavelength region [3] However so
far there is no single opinion concerning the mechanism of edge emission in ZnSe crystals In [4]
the centers of edge emission are considered to be due to the isolated oxygen OSe-centers and distant
OSe-OSe - pairs The authors of [5] believe that this is due to the recombination of donor-acceptor
pairs The nature of the impurity luminescence also causes heated debate among researchers
The development of luminescence centers models is constrained by the lack of information (or
its complete absence) on the kinetic parameters of the observed luminescence bands radiation and
their dependence on the experimental conditions The purpose of the research is to investigate the
spectral and kinetic characteristics of pulse luminescence in ZnSe crystals with different previous
history grown by different technologies in irradiation by a pulsed high-current electron beam of
nanosecond duration
The practical significance of the work is defined by the possibility to use the findings for
creating the model of energy transitions in ZnSe which promotes the development of new optical
devices with electron excitation
Experimental
To study the luminescence of ZnSe was used the technique of pulse luminescent spectrometry
with nanosecond time resolution [6] was used This method has several advantages compared to
stationary methods of research Additional analytical capabilities of luminescent spectral analysis
by using a pulsed spectrometer are provided by the use of nanosecond high-current electron beams
as well as the possibility of extracting useful information about the luminescence centers from the
kinetic characteristics of luminescence decay The spectrum and its evolution over the time after the
excitation pulse are defined by the technology of the crystal growth
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation source was a pulsed electron accelerator with the parameters average electron
energy in the beam of ~ 025 MeV the current pulse duration FWHM of ~ 15 ns The test sample
was set at an angle of 45deg to the direction of the electron flow The samples were cooled by the
industrial microcryogenic system MSMR-110N-3220 which allows cooling a sample down to 125
K without liquid helium or nitrogen Pulse cathodoluminescence of zinc selenide crystals was
investigated in the spectral range 440 - 750 nm at 15 and 300 K The glow of the sample was
projected by a lens onto the entrance slit of the monochromator MDR-204 and detected by PMT-84
and the storage oscilloscope Tektronix TDS 2022 The time resolution of the recording channel was
~ 15 ns the spectral resolution made ~ 00015 eV The luminescence spectra were normalized by
taking into account the spectral sensitivity of the spectrometer optical path The electron beam
energy was measured by radiation-chemical method
Intentionally undoped ZnSe single-crystals with different previous history were used as
samples Samples 1 and 2 were obtained by Davydov-Markov method sample 3 was grown
by Bridgman method
Results and Discussion
The absorption edge of the crystals may provide important information on the band gap and
defects in a crystal lattice The absorption spectra of the samples were measured by a
spectrophotometer SF-256 at 300 K As can be seen from Fig 1 the absorption edge of the ZnSe
crystals is shifted to longer wavelengths compared to fundamental absorption edge of pure ZnSe
which position is defined by free exciton FEZnSe (λ ~ 460 nm at 300 K)
Fig1 Absorption spectra of ZnSe crystals at 300 K
The absorption spectra of the samples 1 and 2 are close to each other this may be caused
by the same nature of the defects responsible for the absorption edge in these crystals The spectrum
of the sample 3 is shifted to longer wavelengths by ~ 10 nm compared to the absorption spectra
of the samples 1 and 2 and has no sharp edges indicating high concentration of both shallow
and deep levels in the band gap of the crystal
The spectral and kinetic characteristics of the pulse cathodoluminescence in ZnSe was
measured at the electron beam energy density 002 Jcm2 (G = 10
26 cm
-3 s
-1) In the luminescence
spectra of the samples 1 and 2 measured at 300 K we observed one band with the maxima at λ
= 470 nm and λ = 468 nm respectively Its decay time was τ le 15 ns The spectrum of the sample
3 is distinguished by the band in the long wavelength region with the peak at λ = 550 nm The
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
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editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
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(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
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All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
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the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
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IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
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Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Eurasian Physical Technical Journal
Vol 8 No 1(15) 2011
CONTENTS
CONDENSED MATTER PHYSICS
Time-Resolved Luminescent Spectrometry Of Zink Selenide Crystals
VI Oleshko SS Vilrsquochinskaya SG Gorina
3
Superficial Tension Of Pure Metals VM Jurov
10
About Luminescent Properties Of Monocrystals Of The Difficult Sulfates Activated By Thallium
K S Baktybekov MK Myrzakhmet M Nikl V Jerry K Bekmyrza
15
HEAT PHYSICS HYDRODYNAMICS ENERGETIC
Gravitational Convection In Gas System Ar ndash N2
IV Poyarkov
19
Nonlinear Fractals And Exciton Formations In Nanostructured Semiconductors
ZZh Zhanabayev TYu Grevtseva
23
Hydrodynamics Of Hydrocyclone With Built-In Water Injector
L Minkov M Farghaly J Dueck
29
DEVICES AND METHODS OF EXPERIMENT
The Results Of ldquoVibration-Seismic-Module-Solid Massif-Disturbancerdquo System Simulation
Modeling
Y M Smirnov BM Kenzhin MA Zhurunova
42
Analysis Of The Procedure Lcas In Transport Networks Ngsdh
DM Zakiev GPAmochaeva RA Mursalin
49
Research Of Influence Of Speech Codecs On Transmission Quality Of The Digital Signal
ZhK Ishchanova GP Amochaeva AK Tussupbekova
56
2
3
UDC 53924 53921
TIME-RESOLVED LUMINESCENT SPECTROMETRY OF ZINK SELENIDE
CRYSTALS
VI Oleshko SS Vilrsquochinskaya SG Gorina
National Research Tomsk Polytechnic University 634050 Russia Tomsk Lenin Avenue 30 svetlanagorinamailru
The spectral and kinetic characteristics of pulse cathodoluminescence of undoped ZnSe single-crystals
grown by sublimation from the vapor phase (Davydov-Markov method) and by flux growth (Bridgman
method) have been measured Three groups of bands were found in the spectra of radiative recombination of
zinc selenide exciton edge emission and bands due to the recombination of carriers in deep centers The
spectral-kinetic characteristics of the edge emission in ZnSe crystals with different previous history have
been studied It was found that the number of edge emission series the ratio of their intensities and spectral
position are to be determined by the previous history of crystals It is shown that the total intensity of the
edge emission reduces more than tenfold with the temperature increase in the range of 15 - 80 K The results
obtained show that the properties of the edge emission can be well described by the model of donor-acceptor
pairs
Keywords cathodoluminescence sublimation single-crystals edge emission radiative recombination
Introduction
AIIB
VI semiconductors are considered to be promising materials in optoelectronics and infrared
technology The first information about the research of luminescent characteristics of ZnSe at low
temperatures dates back to 1960 It was reported about the edge emission observed as a large
number of sharp lines in ZnSe photoluminescence spectra in the temperature range 42 - 77 K [1 2]
and the impurity radiation observed as broad bands in longer wavelength region [3] However so
far there is no single opinion concerning the mechanism of edge emission in ZnSe crystals In [4]
the centers of edge emission are considered to be due to the isolated oxygen OSe-centers and distant
OSe-OSe - pairs The authors of [5] believe that this is due to the recombination of donor-acceptor
pairs The nature of the impurity luminescence also causes heated debate among researchers
The development of luminescence centers models is constrained by the lack of information (or
its complete absence) on the kinetic parameters of the observed luminescence bands radiation and
their dependence on the experimental conditions The purpose of the research is to investigate the
spectral and kinetic characteristics of pulse luminescence in ZnSe crystals with different previous
history grown by different technologies in irradiation by a pulsed high-current electron beam of
nanosecond duration
The practical significance of the work is defined by the possibility to use the findings for
creating the model of energy transitions in ZnSe which promotes the development of new optical
devices with electron excitation
Experimental
To study the luminescence of ZnSe was used the technique of pulse luminescent spectrometry
with nanosecond time resolution [6] was used This method has several advantages compared to
stationary methods of research Additional analytical capabilities of luminescent spectral analysis
by using a pulsed spectrometer are provided by the use of nanosecond high-current electron beams
as well as the possibility of extracting useful information about the luminescence centers from the
kinetic characteristics of luminescence decay The spectrum and its evolution over the time after the
excitation pulse are defined by the technology of the crystal growth
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation source was a pulsed electron accelerator with the parameters average electron
energy in the beam of ~ 025 MeV the current pulse duration FWHM of ~ 15 ns The test sample
was set at an angle of 45deg to the direction of the electron flow The samples were cooled by the
industrial microcryogenic system MSMR-110N-3220 which allows cooling a sample down to 125
K without liquid helium or nitrogen Pulse cathodoluminescence of zinc selenide crystals was
investigated in the spectral range 440 - 750 nm at 15 and 300 K The glow of the sample was
projected by a lens onto the entrance slit of the monochromator MDR-204 and detected by PMT-84
and the storage oscilloscope Tektronix TDS 2022 The time resolution of the recording channel was
~ 15 ns the spectral resolution made ~ 00015 eV The luminescence spectra were normalized by
taking into account the spectral sensitivity of the spectrometer optical path The electron beam
energy was measured by radiation-chemical method
Intentionally undoped ZnSe single-crystals with different previous history were used as
samples Samples 1 and 2 were obtained by Davydov-Markov method sample 3 was grown
by Bridgman method
Results and Discussion
The absorption edge of the crystals may provide important information on the band gap and
defects in a crystal lattice The absorption spectra of the samples were measured by a
spectrophotometer SF-256 at 300 K As can be seen from Fig 1 the absorption edge of the ZnSe
crystals is shifted to longer wavelengths compared to fundamental absorption edge of pure ZnSe
which position is defined by free exciton FEZnSe (λ ~ 460 nm at 300 K)
Fig1 Absorption spectra of ZnSe crystals at 300 K
The absorption spectra of the samples 1 and 2 are close to each other this may be caused
by the same nature of the defects responsible for the absorption edge in these crystals The spectrum
of the sample 3 is shifted to longer wavelengths by ~ 10 nm compared to the absorption spectra
of the samples 1 and 2 and has no sharp edges indicating high concentration of both shallow
and deep levels in the band gap of the crystal
The spectral and kinetic characteristics of the pulse cathodoluminescence in ZnSe was
measured at the electron beam energy density 002 Jcm2 (G = 10
26 cm
-3 s
-1) In the luminescence
spectra of the samples 1 and 2 measured at 300 K we observed one band with the maxima at λ
= 470 nm and λ = 468 nm respectively Its decay time was τ le 15 ns The spectrum of the sample
3 is distinguished by the band in the long wavelength region with the peak at λ = 550 nm The
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
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Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
3
UDC 53924 53921
TIME-RESOLVED LUMINESCENT SPECTROMETRY OF ZINK SELENIDE
CRYSTALS
VI Oleshko SS Vilrsquochinskaya SG Gorina
National Research Tomsk Polytechnic University 634050 Russia Tomsk Lenin Avenue 30 svetlanagorinamailru
The spectral and kinetic characteristics of pulse cathodoluminescence of undoped ZnSe single-crystals
grown by sublimation from the vapor phase (Davydov-Markov method) and by flux growth (Bridgman
method) have been measured Three groups of bands were found in the spectra of radiative recombination of
zinc selenide exciton edge emission and bands due to the recombination of carriers in deep centers The
spectral-kinetic characteristics of the edge emission in ZnSe crystals with different previous history have
been studied It was found that the number of edge emission series the ratio of their intensities and spectral
position are to be determined by the previous history of crystals It is shown that the total intensity of the
edge emission reduces more than tenfold with the temperature increase in the range of 15 - 80 K The results
obtained show that the properties of the edge emission can be well described by the model of donor-acceptor
pairs
Keywords cathodoluminescence sublimation single-crystals edge emission radiative recombination
Introduction
AIIB
VI semiconductors are considered to be promising materials in optoelectronics and infrared
technology The first information about the research of luminescent characteristics of ZnSe at low
temperatures dates back to 1960 It was reported about the edge emission observed as a large
number of sharp lines in ZnSe photoluminescence spectra in the temperature range 42 - 77 K [1 2]
and the impurity radiation observed as broad bands in longer wavelength region [3] However so
far there is no single opinion concerning the mechanism of edge emission in ZnSe crystals In [4]
the centers of edge emission are considered to be due to the isolated oxygen OSe-centers and distant
OSe-OSe - pairs The authors of [5] believe that this is due to the recombination of donor-acceptor
pairs The nature of the impurity luminescence also causes heated debate among researchers
The development of luminescence centers models is constrained by the lack of information (or
its complete absence) on the kinetic parameters of the observed luminescence bands radiation and
their dependence on the experimental conditions The purpose of the research is to investigate the
spectral and kinetic characteristics of pulse luminescence in ZnSe crystals with different previous
history grown by different technologies in irradiation by a pulsed high-current electron beam of
nanosecond duration
The practical significance of the work is defined by the possibility to use the findings for
creating the model of energy transitions in ZnSe which promotes the development of new optical
devices with electron excitation
Experimental
To study the luminescence of ZnSe was used the technique of pulse luminescent spectrometry
with nanosecond time resolution [6] was used This method has several advantages compared to
stationary methods of research Additional analytical capabilities of luminescent spectral analysis
by using a pulsed spectrometer are provided by the use of nanosecond high-current electron beams
as well as the possibility of extracting useful information about the luminescence centers from the
kinetic characteristics of luminescence decay The spectrum and its evolution over the time after the
excitation pulse are defined by the technology of the crystal growth
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation source was a pulsed electron accelerator with the parameters average electron
energy in the beam of ~ 025 MeV the current pulse duration FWHM of ~ 15 ns The test sample
was set at an angle of 45deg to the direction of the electron flow The samples were cooled by the
industrial microcryogenic system MSMR-110N-3220 which allows cooling a sample down to 125
K without liquid helium or nitrogen Pulse cathodoluminescence of zinc selenide crystals was
investigated in the spectral range 440 - 750 nm at 15 and 300 K The glow of the sample was
projected by a lens onto the entrance slit of the monochromator MDR-204 and detected by PMT-84
and the storage oscilloscope Tektronix TDS 2022 The time resolution of the recording channel was
~ 15 ns the spectral resolution made ~ 00015 eV The luminescence spectra were normalized by
taking into account the spectral sensitivity of the spectrometer optical path The electron beam
energy was measured by radiation-chemical method
Intentionally undoped ZnSe single-crystals with different previous history were used as
samples Samples 1 and 2 were obtained by Davydov-Markov method sample 3 was grown
by Bridgman method
Results and Discussion
The absorption edge of the crystals may provide important information on the band gap and
defects in a crystal lattice The absorption spectra of the samples were measured by a
spectrophotometer SF-256 at 300 K As can be seen from Fig 1 the absorption edge of the ZnSe
crystals is shifted to longer wavelengths compared to fundamental absorption edge of pure ZnSe
which position is defined by free exciton FEZnSe (λ ~ 460 nm at 300 K)
Fig1 Absorption spectra of ZnSe crystals at 300 K
The absorption spectra of the samples 1 and 2 are close to each other this may be caused
by the same nature of the defects responsible for the absorption edge in these crystals The spectrum
of the sample 3 is shifted to longer wavelengths by ~ 10 nm compared to the absorption spectra
of the samples 1 and 2 and has no sharp edges indicating high concentration of both shallow
and deep levels in the band gap of the crystal
The spectral and kinetic characteristics of the pulse cathodoluminescence in ZnSe was
measured at the electron beam energy density 002 Jcm2 (G = 10
26 cm
-3 s
-1) In the luminescence
spectra of the samples 1 and 2 measured at 300 K we observed one band with the maxima at λ
= 470 nm and λ = 468 nm respectively Its decay time was τ le 15 ns The spectrum of the sample
3 is distinguished by the band in the long wavelength region with the peak at λ = 550 nm The
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
Devices and methods of experiment Lying within the above areas scientific-technical information scientific life chronicles reviews may be published
by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
4 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation source was a pulsed electron accelerator with the parameters average electron
energy in the beam of ~ 025 MeV the current pulse duration FWHM of ~ 15 ns The test sample
was set at an angle of 45deg to the direction of the electron flow The samples were cooled by the
industrial microcryogenic system MSMR-110N-3220 which allows cooling a sample down to 125
K without liquid helium or nitrogen Pulse cathodoluminescence of zinc selenide crystals was
investigated in the spectral range 440 - 750 nm at 15 and 300 K The glow of the sample was
projected by a lens onto the entrance slit of the monochromator MDR-204 and detected by PMT-84
and the storage oscilloscope Tektronix TDS 2022 The time resolution of the recording channel was
~ 15 ns the spectral resolution made ~ 00015 eV The luminescence spectra were normalized by
taking into account the spectral sensitivity of the spectrometer optical path The electron beam
energy was measured by radiation-chemical method
Intentionally undoped ZnSe single-crystals with different previous history were used as
samples Samples 1 and 2 were obtained by Davydov-Markov method sample 3 was grown
by Bridgman method
Results and Discussion
The absorption edge of the crystals may provide important information on the band gap and
defects in a crystal lattice The absorption spectra of the samples were measured by a
spectrophotometer SF-256 at 300 K As can be seen from Fig 1 the absorption edge of the ZnSe
crystals is shifted to longer wavelengths compared to fundamental absorption edge of pure ZnSe
which position is defined by free exciton FEZnSe (λ ~ 460 nm at 300 K)
Fig1 Absorption spectra of ZnSe crystals at 300 K
The absorption spectra of the samples 1 and 2 are close to each other this may be caused
by the same nature of the defects responsible for the absorption edge in these crystals The spectrum
of the sample 3 is shifted to longer wavelengths by ~ 10 nm compared to the absorption spectra
of the samples 1 and 2 and has no sharp edges indicating high concentration of both shallow
and deep levels in the band gap of the crystal
The spectral and kinetic characteristics of the pulse cathodoluminescence in ZnSe was
measured at the electron beam energy density 002 Jcm2 (G = 10
26 cm
-3 s
-1) In the luminescence
spectra of the samples 1 and 2 measured at 300 K we observed one band with the maxima at λ
= 470 nm and λ = 468 nm respectively Its decay time was τ le 15 ns The spectrum of the sample
3 is distinguished by the band in the long wavelength region with the peak at λ = 550 nm The
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
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by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
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length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
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Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
5
study of the kinetic characteristics of this band showed that it consists of three components with the
relaxation time τ1 = 2 μs τ2 = 15 μs and τ3 = 50 μs
After 25 μs after the excitation pulse in the spectrum of the sample 3 only one broad (ΔE12 ~
032 eV) band could be observed with the peak at λ = 600 nm and decay time τ1 = 15 μs and τ2 = 50
μs The authors in [3] explain this band as one caused by Cu impurity ~ 510-6
in ZnSe crystals
In [7] the interpretation of the bands of about 600 nm based on the theory of band anticrossing
which determines the initiated by oxygen splitting of the conduction band is proposed
At 15 K the emission lines of bound excitons I1 at λ = 448 nm with a relaxation time τ le 15 ns
and phonon replicas I1 - LO (Fig 2-4) can be observed in the pulse cathodoluminescence spectra of
ZnSe crystals measured at the time of the excitation pulse
All the samples along with the exciton spectrum are characterized by multi-band edge emission
in the region of 460-490 nm In this case there are series of equidistant bands with the step between
the components equal to longitudinal optical phonons
The comparative analysis of the luminescence spectra in zinc selenide crystals measured at
different times after the excitation pulse shows that the edge emission can be observed in all the
samples The number of series and intensity of the bands is determined by the previous history of
the crystals
Figures 2-4 show the spectra of edge emission of zinc selenide crystals measured at various
times after the excitation pulse We can see that the spectrum of sample 1 (Fig 2) contains one
series of equidistant bands with a maximum phonon line at λ = 462 nm and its repetitions with the
maxima at 467 472 and 478 nm
Fig 2 Pulse cathodoluminescence spectra of ZnSe sample 1 measured at various times after excitation
pulse at 15 К
There are two series of edge emission in the spectrum of the crystal 2 (Fig 3) It was
established that only short-wave series (λ ~ 462 467 472 nm) can be observed in the spectrum
measured after 100 ns after the excitation pulse
Over the time the situation changed First the emission lines of the short-wave series shifted to
lower energies and their form changed At the initial time the width of the edge emission lines was
002 eV and over the time it decreased to 0009 eV Secondly along with a short-wave series (λ ~
4635 4685 4745 480 nm) the long-wave series of edge emission (λ ~ 4655 471 4765 4825
nm) appeared in the emission spectrum measured after 200 μs (Fig 3 b)
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
Devices and methods of experiment Lying within the above areas scientific-technical information scientific life chronicles reviews may be published
by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
6 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 3 Pulse cathodoluminescence spectra of ZnSe sample 2 measured at various times after excitation
pulse at 15 К
The edge emission spectrum of the sample 3 measured after 1 μs after the exciting pulse
(Fig 4) differs from the edge emission spectra of the samples 1 and 2
Fig 4 Pulse cathodoluminescence spectra of ZnSe sample 3 measured at various times after excitation
pulse at 15 К
Its intensity is an order of magnitude smaller than the intensity of the defect - impurity
luminescence band peaking at λ = 550 nm which indicates a very high degree of crystal
defectiveness compared with crystals 1 and 2
The decay kinetics of the pulse cathodoluminescence at λ = 463 nm is described by a
hyperbolic law of electrons and holes concentration reducing which is typical for recombination
luminescence The emission intensity decreases over the time in accordance with the law I~t-1
(Fig 5a)
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
Devices and methods of experiment Lying within the above areas scientific-technical information scientific life chronicles reviews may be published
by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
7
Table 1 The spectral characteristics of ZnSe edge emission measured at different time intervals
after the pulse high-current electron beam at 15 K
Sample 1
Measuring
point After 200 ns After 1 μs After 25 μs
λ nm
(Е eV)
462 (2684 eV)
467 (2655 eV)
472 (2627 eV)
478 (2594 eV)
4625 (2681 eV)
4675 (2652 eV)
474 (2616 eV)
463 (2678 eV)
4685 (2647 eV)
474 (2616 eV)
Sample 2
Measuring
point After 200 ns After 25 μs After 20 μs After 200 μs
λ nm
(Е eV)
462 (2684 eV)
4675 (2652 eV)
473 (2622 eV)
463 (2678 eV)
468 (2650 eV)
474 (2616 eV)
463 (2678 eV)
465 (2667 eV)
4685 (2647 eV)
4705 (2635 eV)
474 (2616 eV)
476 (2606 eV)
4795 (2586 eV)
4635 (2675 eV)
4655 (2664 eV)
4685 (2647 eV)
471 (2633 eV)
4745 (2613 eV)
4765 (2602 eV)
480 (2583 eV)
4825 (2570 eV)
Sample 3
Measuring
point After 200 ns After 1 μs
λ nm
(Е eV)
4615 (2687 eV)
473 (2622 eV)
464 (2672 eV)
468 (2650 eV)
475 (2611 eV)
Fig 5 Decay kinetics of pulse cathodoluminescence of ZnSe sample 2 at 15 К а) at λ = 463 nm b) at
λ = 640 nm
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
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by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
8 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The dependence of the edge emission intensity on the temperature was researched Edge
emission was found to experience strong temperature quenching with temperature increasing
(Fig 6)
Fig 6 Dependence of edge emission intensity (at λ = 463 nm) of ZnSe sample 2 on temperature
All observed dependences which characterize ZnSe bands near the fundamental absorption
edge are typical for the luminescence of donor-acceptor pairs Notably the presence of the
emission spectrum equidistant structure which characterizes the interaction with photons of the
lattice the donor-acceptor luminescence kinetic is not exponential the luminescence spectra
measured at different time intervals after the excitation pulse are different Predominantly short-
range pairs recombine at the initial time after the excitation Distant pairs illuminate later due to the
low probability of interimpurity transitions As a result with the time after the excitation pulse
short-wave and long-wave series bands of ZnSe crystals shift over 001 eV to low-energy spectral
region The edge emission intensity strongly decreases with the temperature increasing from 15 to
80 K
Electronic transition mechanisms and the nature of the defects responsible for different series
of edge emission in crystals AIIB
VI are still under discussion [3 - 8] It is considered that donors are
shallow (ЕD = 0015 eV for ZnSe) and acceptors corresponding to both series are deep (ЕA = 012
eV for ZnSe) and are of the same origin [1] The donor-acceptor pairslsquo luminescence has the
following mechanism Nonequilibrium electron is nonradiatively trapped by positively charged
ionized donor a hole is trapped by ionized acceptor and then the radiative electron transition from
donor to acceptor occurs The emitted photon energy is determined by the equation
(1)
where Eg is a band gap ED and EA are energy positions of donor and acceptor levels relative to
the edges of nearest bands R is distance between impurities e is electron charge ε is dielectric
constant The Equation (1) is written without taking into account a small summand which
characterizes the difference between interimpurities interaction and the Coulomb interaction of the
short-range pairs
Currently no researches clearly point to the physicochemical nature of the defects responsible
for different series of edge emission in undoped crystals of AIIB
VI group Intrinsic defects and
impurity atoms are assumed to be donors and acceptors Clarifying nature of the centers which are
responsible for the crystals edge emission requires individual study beyond the scope of this
research
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
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(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
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All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
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the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
9
Defect-impurity luminescence bands are observed in the range 490-750 nm in the samples
spectra measured at 15 K A broad band (ΔE12 ~ 015 eV) with the maximum at λ = 492 nm and
relaxation time τ ~ 500 ns appears in spectra of crystals 1 and 2 at the time of the excitation
pulse Its occurrence is associated with the occurrence of uncontrolled impurities of tellurium and
oxygen in the crystal lattice of ZnSe [7]
A broad band (ΔE12 ~ 02 eV) with the maximum at λ = 600 nm appears in the spectra of
samples 1 and 2 (Fig 2 3) measured after a few microseconds after the excitation pulse at 15
K The luminescence intensity at λ = 600 nm decays according to the hyperbolic law I~t-1
(Fig 5 b)
This band intensity decreases more than tenfold with the temperature increase in the range of 15 -
150 K
The bands appearance observed in the samples spectra in the range 520 - 650 nm (Fig 3-5)
measured over the time after the excitation pulse at 15 K can be explained by the theory of band
anticrossing and oxygen and copper impurities in the crystals [8] In this case the transitions to the
Cu acceptor level take place from the narrow band of strongly localized states and extended states
band splitted by isoelectronic impurity of conduction band oxygen
Conclusions
I The evolution of the edge emission spectra of ZnSe crystals grown by various methods is
researched in the time interval of 10-7
ndash 10-2
s using the method of pulsed spectrometry with
nanosecond time resolution The number of edge emission series their intensities ratio and spectral
position can be determined by the previous history of the crystals
II The edge emission time shift of ZnSe crystals after the excitation pulse is measured It is
shown that depending on the crystal type the maxima of edge emission bands shift to longer
wavelengths by 0006 - 0014 eV
III The dependence of the edge emission on temperature is researched It is shown that the total
intensity of the edge emission decreases more than tenfold with the temperature increase in the
range of 15 - 80 К
IV The results obtained confirm the donor-acceptor mechanism of the edge luminescence in
zinc selenide crystals
V The bands found in the range of 490 - 750 nm indicate the intrinsic and extrinsic defects in
the ZnSe samples
References
1 DCReynolds LSPedrotti OWLarson J Appl Phys V32 10 p2250 (1961)
2 PJDean JLMerz Phys Rev V178 3 p1310 (1969)
3 LYMarkovsky IAMironov YSRyzhkin Optics and Spectroscopy V27 1 p167 (1969)
4 NKMorozova VAKuznetsov VDRyzhikov and alt Zink selenide Production and optical properties
1992 M Nauka 96 p
5 VSwaminathan LCGreene Phys Rev B V14 12 p5351 (1976)
6 VMLisitsyn VIKorepanov The spectral measurements with temporal resolution 2007 Tomsk TPU
Publishing House 94 p
7 NKMorozova DAMideros Proceedings of the universities Electronics 3 p12 (2007)
8 NKMorozova DAMideros EMGavrishchuk VGGalstyan FTS V42 2 p131 (2008)
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
Devices and methods of experiment Lying within the above areas scientific-technical information scientific life chronicles reviews may be published
by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
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The following files must be submitted via e-mail
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IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
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Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
10 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 539109 53895405 62190257
SUPERFICIAL TENSION OF PURE METALS
VMJurov
Karaganda state university name after EA Buketov Kazakhstan Karaganda University 28 excitonlistru
In work questions of experimental definition of a superficial tension of massive samples and
nanoparticles pure metals are considered The model allowing with good accuracy to define size of a
superficial tension its dependence on temperature and on the size of particles is offered Results of
calculations are compared to known models and a method of zero creepraquo
Work is executed within the limits of the Program of basic researches of Ministry of Education and
Science of the Republic of Kazakhstan The grant 1034 FI
Keywords superficial tension massive samples nanoparticles magnetic susceptibility nanocrystals
Experimental definition of a superficial tension of solid states is complicated by that their
molecules (atoms) are deprived possibility freely to move The exception makes a plastic current of
metals at the temperatures close to a melting point [1]
Recently we had been offered methods of experimental definition of a superficial tension of
solid dielectrics and the magnetic materials based on universal dependence of physical properties
of solid state on its sizes [2-4] In this work we spend comparison of our method with a method of
laquozero creepraquo
A method of laquozero creepraquo the sample (a long thread a foil) heat up to enough heat so it starts to
be reduced on length under the influence of superficial pressure The external force is put to the
sample supporting invariable the form of the sample On size of this force define size of a
superficial tension Experimental data for some metals are taken [5] from work and are resulted in
table 1
Table 1 Experimental on a superficial tension of some metals and their comparison with our method
Metal Temperature ordmС σ jm2 [5]
(solid phase)
σ jm2
(our method)
σ jm2 [1]
(liquid phase)
Ag 930 114 plusmn 009 - 0126
Al 180 114 plusmn 02 1070 0093
Au 1040 137 plusmn 015 1312 0132
Cu 900 175 plusmn 009 - 0177
Pt 1310 23 plusmn 08 - 0208
W 1750 29 plusmn 03 - -
Zn 380 083 - -
In work [6] and a number of others we receive the formula which describes dependence of
physical properties of a solid state on its size
r-1
dAA(r)
0 (1)
Here А0 - physical properties of the massive sample A (r) - physical properties of a small
particle or a thin film d - critical radius or a critical thickness of a film since which dimensional
effects are shown For critical radius we receive the formula
RT
2d
(2)
Here - a superficial tension of the massive sample ndash a molar volume R - a gas constant
T - temperature
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
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Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
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(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
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the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
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scientific area of the paper
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ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
11
To illustrate a method we will result our experimental results described in work [7] Specific
magnetization of 43
OFe was investigated by us on vibrating magnetometer The size of grain of
43OFe was defined on a microscope Results are shown in figure 1
Fig 1 Dependence of a relative magnetic susceptibility on diameter of grain of Fe3O4
In coordinates aeligaelig0 ~1r the experimental curve is straightened according to (1) giving value
d = 036 μm For a 43
OFe = 445 sm3mol and from a parity (2) for a superficial tension it
is received = 100710
3 ergsm
2 Calculation of density of superficial energy for a
43OFe spent
by many authors [8] gives = 10110
3 ergsm
2 that coincides with the size received by us
In recently left monography of the japanese and russian physicists [9] it is considered that
reduction of temperature of fusion of small particles is connected by that atoms on a surface have
smaller number of neighbours than in volume are hence less strong connected and less limited in
the thermal movement In the same place it is noticed that usually temperature reduction of
nanocrystals in inverse proportion to its size (fig 2) However the theory of this effect while is not
present
Fig 2 Fusion temperature of nanocrystals gold as function of their size [9]
12 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
If to take advantage of analogy of scalar fields we receive the equation similar (1) for
temperature of fusion of small particles
r
d1ТТ
0пл
(3)
where 0
T - temperature of fusion of the massive sample
Using the experimental results shown on a figure 2 it is possible (3) to define a superficial
tension of small particles of gold under our formula At temperature Т = 1040 ordmС the size of a
superficial tension of gold has appeared equal = 1312 jm2 This size slightly differs from the
size of a superficial tension received in a method of laquozero creepraquo (table 1)
In work [10] for a nanocrystals aluminium the experimental curve similar to a curve shown on
figure 2 is received Calculation of size of a superficial tension under our formula (3) has yielded
the following result = 1070 jm2 This size also slightly differs from the size of a superficial
tension received in a method of laquozero creepraquo (table 1)
From the formula (2) linear dependence of a superficial tension on temperature turns out
T (4)
Using given tables 1 it is easy to calculate factor Results of calculation are shown in
table 2
Table 2 Values of temperature factor α for a superficial tension of metals
Metal αmiddot10-3 jmiddotm-2middotК-1 Metal αmiddot10-3 jmiddotm-2middotК-1
Ag 094 Pt 15
Al 25 W 14
Au 11 Zn 12
Cu 15 - -
If to consider an error of measurements (table 1) value of factor equally asymp 10-3
jmiddotm-2
middotК-1
for
all metals In work [11] linear dependence between a superficial tension and temperature of fusion of an
element also is received This dependence is illustrated in figure 3
Fig 3 Correlation dependence of a superficial tension on temperature of fusion [11]
In this figure experimental data for 54 elements of a periodic table of Mendeleyev taken of [12
13] and a straight line - calculation under the formula are designated
13
T107020m
3 (5)
where the numerical factor is received by a method of the statistical analysis The
proportionality factor in the formula (5) matters close received by us
Thus the estimation of a superficial tension of metals can be made on their temperature of
fusion and factor asymp 10-3
jmiddotm-2
middotК-1
under the formula (4)
From table 1 follows that in a liquid phase of metals the superficial tension decreases for all
metals approximately in 10 times
Bases of thermodynamics of curvilinear borders of section have been put in pawn still J Gibbs
[14] Then R Tolmen and its followers have reduced this problem to the account of dimensional
dependence of a superficial tension (see for example [15])
In 1949 RTolmen has deduced the equation for a superficial tension
1
s)R21(
(6)
Here
- a superficial tension for a flat surface s
R - radius of a surface of a tension gt 0 -
distance between the molecular a dividing surface and a surface of a tension for flat border
The order of size of parameter named constant of Tolmen should be comparable with
effective molecular diameter RAt formula of Tolmen can be copied in a kind
R21
(7)
Thus approach of Tolmen is reduced to the amendment account on curvature of a surface to
macroscopical value of a superficial tension
It is necessary to notice what experimentally to
define constant of Tolmen it is not obviously possible For small R AIRusanov [16] has received linear dependence
KR (8)
Here K - proportionality factor The formula (8) is received on the basis of thermodynamic
consideration and should be applicable to small objects of the various nature However borders of
applicability of the formula (8) and values of parameter K remain till now practically not
investigated
Within the limits of our model (the formula 1 and 2) for К easy to receive
A
)r(A1
2
RTK
0
(9)
Here 0
A - the measured physical size of the massive sample - the molar volume T -
temperature R - a gas constant Formulas 1 and 2 are thus true
)r
d1(A)r(A
0
RT
2d
(10)
The criterion of applicability of the formula of Rusanov AI will be expressed in a kind (table 3)
RT
2dr
k
(11)
Table 3 Criterion of applicability of the linear formula of AIRusanov
Metal rk nm Metal rk nm
Pb 09 Ag 11
Sn 08 Au 11
Fe 12 Cu 10
From table 3 it is visible that for all metals k
r has size about 1 nanometer Surprisingly but the
same order has the critical size k
r a germ at formation of crystals
14 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Lets notice also that constant of Tolmen is equal in our model 2rk
asymp 05 nanometers
If to take advantage of an analogy method it is possible to receive the formula of type (1) or (7)
r
r1)r( k
0
(12)
Using the formula (11) it is possible to calculate k
r Then using given tables (1) and the
formula (12) we calculate value of a superficial tension of particles in the size 2 and 10
nanometers Results for some metals at Т = 300 K are presented in table 4
Table 4 The superficial tension of particles some metals
Metal Т К σ(r) r =2 nm (jm2) σ(r) r =10 nm (jm2)
Ag 300 0155 0257
Au 300 0198 0304
Cu 300 0180 0396
From table 4 it is visible that already at the size of particles 10 nanometers size of a superficial
tension there are more comes nearer to size of a superficial tension of the massive sample (see
table (1)
References
1 AJ Hohstein A superficial a tension of solide states and adsorption 1976 М Nauka 256 p
2 V M Jurov et al Kazakhstan Patent 57691 2009 The way of measurement of a superficial tension of
solide states
3 V M Jurov et al Kazakhstan Patent 58155 2009 The way of measurement of a superficial tension and
density of superficial conditions of isolators
4 V M Jurov et al Kazakhstan Patent 58158 2009 The way of measurement of a superficial tension of
magnetic materials
5 V I Roldugin Surface physical chemistry 2008 - Dolgoprudno the Publishing House Intelligence 568 p
6 V M Jurov Vestnik KarGU Physics 1 (45) p23 (2007)
7 V M Jurov Modern problems of science and education 4 p 152 (2009)
8 VS Vonsovsky Magnetizm 1971 М Nauka - 1032 p
9 К Oura V GLifshits AA Saranin et al Introduction in surface physics 2006 М Nauka 490 p
10 VG Kotlyar AV Zotov AA Saranin et al Phys Rev B V 66 16 p 165401-1 (2002)
11 SS Rehviashvili EV Kishtikova R A Karmokova et al Letters in JTF V 33 2 p 1(2007)
12 С Ono S Kondo Molecular the theory superficial a tension 1963 М IL 284 p
13 V I Nizhenko LI Floka Superficial tension of liquid metals and alloys 1981 М Metallurgy 208 p
14 J V Hibbs Thermodynamic works 1950 М ndash L GITTL 303 p
15 O V Almjasheva VV Hussars OV Lebedev The superficial phenomena 2004 SPb Publishing house
LETI 28 p
16 AI Rusanov Phase of balance and the superficial phenomena 1967 L Chemistry ndash 346 p
15
UDC 5392
ABOUT LUMINESCENT PROPERTIES OF MONOCRYSTALS OF THE DIFFICULT
SULFATES ACTIVATED BY THALLIUM
K S Baktybekov MKMyrzakhmet MNikl VJerry KBekmyrza
LNGumilyov Eurasian National university Kazakhstan Astana kbtrmailru
Institute of Physics of Academy of Sciences of the Czech Republic Prague niklfzucz
Luminescence centres in the ammonium sulphate crystals with an impurity of thallium and in the mixed
crystals are explored It is shown that these centres are the one-charging thallium ion Two various
positions of replacement feeblly affect scintillation performances of these crystals
Keywords luminescence centres mixed crystals scintillation performances radio luminescence spectra of absorption
Introduction
Crystals of sulfate of ammonium and the mixed crystals of sulfate of potassium and lithium are
interesting with some phases caused by various behaviors of cations and anions at various
temperatures
Ammonium sulfate at 223 K to turns from high-temperatured the para-electric form I in segne-
electrical phase II [1] Forms are ortorombical group forms I Рпат and forms II - Рпа21 is spatial
Under a condition for ortorombical elementary cellsgtgt with the axis with in a phase II is a
direction spontaneous polarization The phase I possesses three mirror planes аb bc both the expert
and the inversion center and the phase II doesnt have center of inversion and a reflection plane аb
In both forms para-electric and segneelectric for ammonium ions in a lattice there is
environment of two types Types of ions corresponding to them are designated as NH4 (I) and NH4
(II [1] Ion NH4 (I) has five sulfates-ions in the nearest environment and ion NH4 (II) - six (in both
phases) Ions NH4 (I) are less mobile than ions of the second type With increase in the
maintenance of ions of potassium temperature transition energy of activation of ions NH4 (I)
decreases also decreases Moreover last type of ions is mainly replaced and in enough enriched
ions potassium the mixed crystals there are only ions NH4 (II) From measurements of time of a
relaxation on a phase I of salt (NH4)2S04 follows that above 300 K ammonium ions begin to diffuse
in a lattice with energy of activation 75 kjmol [2]
Transition IIrarrI partially smooth as thermal capacity measurements have shown It is
accompanied by the gradual reduction of volume reaching as a result approximately 15 thus
compression is concentrated only along an axis and [3] However though transition is also stretched
on an interval approximately in 50 K it comes to the end nevertheless isothermally Thus in the
Curie point sharp change of spontaneous polarization [3] and factors of an elastic pliability [4] is
observed Nevertheless there is no a sharp change in frequencies of librational (torsional)
fluctuations that has been established on long-wave infra-red spectra [5] infra-red spectra and
spectra of combinational dispersion [6] in effective section of dispersion of neutrons [7]
For ammonium sulfates and also the mixed sulfates of potassium and the lithium activated by
thallium remain unsolved questions
bull distinction of optical properties of ions Tl+ for two various positions of potassium with
which they replace
bull optical properties of pair centers Tl+
2 in these crystals
Experiment
Crystals of sulfate of ammonium and the mixed sulfates of lithium and potassium pure and in
the presence of a thallium impurity are grown up from a water solution by a method of slow
16 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
evaporation at room temperature at the Eurasian national university of LNGumilyov
Measurements of optical properties of these crystals are carried on the equipment of department of
optical materials of Institute of Physics of Academy of Sciences of the Czech Republic in Prague
Absorption of crystals was measured at room temperature by means of installation Shimadzu
3101PC a luminescence in a wide range of temperatures from temperature of liquid nitrogen to
500degС ndash spectrofluorimeter HJY 5000M
In fig 1 - 2 are shown the comparison with standard scintillator BGO spectra X-ray all
measured by us it is exemplary The samples activated by thallium always show more intensive
strip of radiation with various intensity (depending on the form of the sample concentration of
thallium quality of a material)
Fig 1 Radio luminescence of crystals LiKSO4
Fig 2 Radio luminescence of crystals NH4SO4 in comparison with the data for ammonium chloride
17
Fig 3 Spectra of absorption of samples at room temperature
Fig 3 spectra of absorption of samples with thallium impurity ndash A-strip Tl+ with a
maximum about 220-230 nanometers are shown
Fig 4 Samples LiKSO4
Fig 5 Spectrum of the photoluminescence of the investigated samples
18 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The excitation spectrum in this strip approximately repeats an absorption A-strip (Fig 6) there
is a high intensity of this strip most likely because of high value spectral absorptive abilities and
arising thereof geometrical effects
Fig 6 A spectrum of excitation of the investigated samples
The photoluminescence and excitation spectra in all crystals are measured by us corresponded
to X-ray and to absorption accordingly Time of attenuation of luminescence is homogeneous
everywhere for a strip of radiation and 410 nanoseconds the disintegration form single-exponent
give for crystals LiKSO4-Tl approximately that is the radiation center is unique and well defined
In radiation spectrum (NH4) 2SO4 there are two strips approximately 295 nanometers and weaker
of 380 nanometers The spectrum of excitation dominating corresponds to absorption spectrum
Time of attenuation of a photoluminescence of the basic strip of 300 nanometers approximately 360
nanoseconds and for weaker strip of 380 nanometers is longer - approximately 600-800
nanoseconds
Photoluminescence NH4Cl Tl is well studied earlier [8] The photoluminescence spectrum
reaches a maximum approximately 370-380 nanometers and there correspond to one strip X-rayed
and its time of attenuation approximately 360 nanoseconds
Conclusions
Thus we have investigated the luminescence centers in the crystals of sulfate of ammonium
activated by thallium and in the mixed crystals It is shown that these centers are one-charging ion
of thallium Two various positions of replacement poorly affect luminescent characteristics of these
crystals
References
1 Parsonige N Staveli L Disorder in crystals Vol 1 М Peace 1982
2 Knispel RR Petch HE Pintar MM JChemPhys 63 390 (1975)
3 Hoshino S Vedam K Okaya Y Pepinsky R Phys Rev 112 405 (1958)
4 Ikeda T Fujibayashi K Nahai T Kobayashi J Phys St Solidi A16 279 (1973)
5 Trefler M Can J Phys 49 1694 (1971)
6 Torrie BH Lin CC Binbrek OS Anderson A (J) Phys Chem Solids 33 697 (1972)
7 Leung PS Taylor TI Havens WW J Chem Phys 48 4912 (1968)
8 Murzakhmetov MK Complex luminescence centers in crystals NH4Cl activated by ions Tl In the book
Phototransformation of energy in atoand molecular systems - Karaganda 1984- pp13-19
Heat Physics Hydrodynamics Energetic 19 UDC 53315
GRAVITATIONAL CONVECTION IN GAS SYSTEM Ar ndash N2
IV Poyarkov
Kazakh National University named after al-Farabi Al-Farabi ave 71 050040 Kazakhstan Almaty p-igorinboxru
A study has been made of the diffusion gravitational convection transition boundary in an
argonnitrogen binary system at different pressures and a constant temperature gradient Research
relative influence two gradients (concentration and temperature) to the density gradient In a
binary system with an unstable stratification of the density observe two mixing regimes - diffusion
and convective mass transfer It has been shown that in the case of isothermal and non-isothermal
mixing the diffusion process is stalled at one and the same pressure The convective mass transfer
becomes less intensive in the presence of a temperature gradient
Keywords diffusion gravitational convection temperature gradient density gradient convective mass transfer
A spontaneous penetration of one substance into another is a phenomenon known as diffusion
which frequently occurs in nature and engineering facilitating an equalization of the concentration
gradient in a given volume The rate of mixing depends on the heat motion of molecules the
smaller the molecular weight and the higher the temperature the shorter the time of full mixing
More intensive mixing can be achieved with the convective mass transfer which is implemented by
force or by provision of special conditions for flows of matter arising due to diffusion processes
The oceanographic investigations which were performed in the latter half of the last century
revealed salt fountains [1 2] representing water regions with a clearly marked density boundary
The laboratory studies [3 4] demonstrated that because of temperature and salinity gradients and a
slower horizontal transport of salt as compared to the heat transfer long narrow convective cells
moving alternately up and down are formed in the bulk of the liquid This convective motion was
called double diffusive convection [5] or gravitational convection Double diffusive convection
appears in a liquid if two conditions are fulfilled namely the liquid contains two or more
components with different diffusion coefficients and these components should make opposite
contributions to the vertical density gradient [6 7] Investigations into melting of ice blocks [8] and
the evolution of ice coats of ponds [9] showed that upon exposure to solar radiation denser
freshwater remains beneath thinner seawater flowing over some slightly sloping vertical layers
formed under the mutual effect of the temperature and salinity gradients
Studies of the thermo-effect in ternary gas mixtures revealed irregular oscillations of the
temperature in the diffusion apparatus [10 11] Later investigations of isothermal ternary gas
mixtures showed that double diffusive convection is possible not only in systems with a stable
stratification of the density but also in systems with a negative density gradient [1215] Studies on
manifestations of the mechanical equilibrium instability in non-isothermal conditions are many
fewer and they deal with the condition of a stable stratification of the mixture density Therefore it
seems reasonable to explore the alteration of the non-isothermal diffusion gravitational
convection regimes with an unstable stratification of the density in the simplest mixture namely a
binary system In this case two (concentration and temperature) gradients are formed making
opposite contributions to the vertical density gradient Therewith conditions for the mass transfer
typical of double diffusive convection are observed
This paper reports experimental data on the processes of mixing in the Ar ndash N2 binary gas
system with a temperature gradient and also presents a theoretical analysis of the stability of the
gas mixture under study
20 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The experiments were performed by the two flask method which is widely used to determine
diffusion coefficients in a wide range of temperatures and pressures [16 17] The two flask
installation consisted of two basic components and thermostat Fig 1 [18] One of the components
was a gas preparation unit made up of a set of needle valves (110) for filling of the temperature-
controlled flasks with initial gases from the cylinders A and B a tank (12) equalizing the pressures
in the flasks and control pressure gages (11)
Fig 1 Experimental arrangement (1)-(10) valves (11) reference pressure gages (12) equalizing tank
(13) bottom flask (14) diffusion capillary (15) top flask (16) thermostat
The second component of the installation was the diffusion apparatus itself It consisted of two
controlled flasks (13 15) with preset volumes VI and VII equal to 628106
m3 which were
connected through a capillary (14) of radius r = 2103
m and length l = 639103
m The heavy gas
Ar was placed in the top flask at a temperature of 2830 01 К while the light gas N2 was poured
into the bottom flask at a temperature of 3430 01 К A study with the top and bottom flasks of
the diffusion apparatus held at a temperature of 2950 01 К was conducted for comparison
The experimental procedure on the installation was as follows The capillary between the flasks
was stopped one of the flasks was evacuated using a backing pump then this flask was washed
several times with the corresponding gas from the cylinder and finally it was filled with the gas to
the experimental pressure An analogous procedure was applied to the other flask The gas pressure
in the flasks of the apparatus was read against reference pressure gages (11) The absolute
experimental pressure was the sum of the atmospheric pressure which was determined by a MBP
manometer-barometer and the excess pressure read by a reference pressure gage As soon as the
installation reached the preset temperature regime the pressure in the flasks was equalized through
a special tank (12) and the excess gas was bled to the atmosphere through a valve (7) Then the
capillary (14) was opened and the experiment start time was noted simultaneously In a certain
period of time (960 s) the apparatus flasks were isolated and the gases were analyzed in a
chromatograph The experimental values of the concentrations were compared with the
corresponding calculated values on the assumption of diffusion [19] If the experimental and
theoretical values of the concentrations coincided non-isothermal diffusion occurred in the system
If these values were considerably different the mass transfer was implemented as free convective
flows
Heat Physics Hydrodynamics Energetic 21
The experimental data can be conveniently presented as the parameter teor
exр
с
c It is seen from
Fig 2 that up to some pressure the parameter is on the order of unity Hence even with an
unstable stratification of the mixture density conditions for molecular diffusion can be formed in
this mixture Starting from a pressure 50p MPa the parameter increases linearly with
growing pressure
Fig 2 Pressure dependence of the parameter The symbols ∆ and denote the experimental data
for argon and nitrogen in stable and unstable states in the case of non-isothermal mixing The symbols
and refer to the isothermal process The solid line corresponds to the calculations made on the
assumption of diffusion
In this situation one can suggest the presence of free convective flows which are due to
instability of the mechanical equilibrium of the mixture It should be noted that in the case of
isothermal and non-isothermal mixing the diffusion process is stalled at one and the same pressure
As can be seen from Fig 2 the parameter is larger for isothermal than non-isothermal
mixing Then the convective mass transfer is more intensive in the absence of a temperature
gradient between the flasks of the diffusion apparatus This is probably due to cross effects
diffusion and thermal diffusion studied in [20] One more reason is that a flow of matter which is
caused by a temperature gradient and an opposite concentration gradient is superimposed on the
total transfer In other words a mechanical equilibrium instability characteristic of double diffusive
convection is formed
One can see that the molecular diffusion gravitational convection takes place in the case of
non-isothermal mixing at a constant temperature gradient The experimental data on mixing in the
Ar ndash N2 system agree with the experimental results as regards the stability boundary A correlation
of from unity within the experimental error in the stable region (to the large and small sides for
argon and nitrogen respectively) presents a distinction from mixing in a binary system under
isothermal conditions It is probably explained by the presence of a heat flow which acts as the
third component
Thus a study has been performed aimed at determining the boundary of transition in a binary
mixture with an unstable stratification of the density in the presence of a temperature gradient It
was shown experimentally that two mixing regimesdiffusion and convective mass
transferoccur in a binary system with an unstable stratification of the density The regime is
changed at a pressure р=05 MPa The intensity of the convective mass transfer is higher during
isothermal mixing than in the case of a temperature gradient which is opposite to the density
gradient
0
5
10
15
20
25
30
0 02 04 06 08
р МPа
22 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
References
1 Stommel Н Arons АВ Blanchard D An oceanographical curiosity the perpetual salt fountain
Deep-Sea Res ndash 1956 ndash Vol 3 ndash P 152-153
2 Gregg MC Cox CS The vertical microstructure of temperature and salinity Deep-Sea Res ndash 1972
ndash Vol 19 ndash P355-376
3 Stern ME The ―salt fountain and thermohaline convection ndash Tellus 1960 ndash Vol 12 ndash Р 172-175
4 Turner JS Stommel HA New case of convection in the presence of combined vertical salinity and
temperature gradients Proc Nat Acad Sci ndash 1964 ndash Vol 52 ndash Р 49-53
5 Turner JS Double-diffusive phenomena Ann Rev Fluid Mech ndash 1974 ndash Vol6 - P 37 ndash 56
6 Hupper HE Turner JS Double diffusive convection Journal of fluid mechanics - 1981 ndash Vol 106
ndash P413 ndash 453
7 Trevor J Mcdougall Double-diffusive convection caused by coupled molecular diffusion Journal of
Fluid Mechanics ndash 1982 ndash Vol 126
8 Huppert HE Turner JS Ice blocks melting into a salinity gradient J Fluid Mech ndash 1980 ndash Vol
100 ndash Р 367-384
9 Martin S Kauffman P The evolution of under-ice melt ponds or double diffusion at the freezing point
Journal of Fluid Mechanics - 1974 ndash Vol 64 ndash Issue 03 ndash P 507-528
10 Miller L Mason E A Oscillating instabilities in multicomponent diffusion Phys Fluids ndash 1966 ndash
Vol 9 N 4 ndash P 711 - 721
11 Miller L Spurling ТН Mason EA Instabilities in ternary diffusion Phys Fluids ndash 1967 ndash Vol 10
N8 ndash P 1809-1811
12 Zhavrin YuI and Kosov VN Effect of temperature on diffusion instability Journal Engineering
Physics and Thermophysics ndash 1988 ndash Vol 55 1 ndash P92-97
13 Zhavrin YuI and Kosov VN Stable diffusion boundaries in three-component gas mixtures Journal
Engineering Physics and Thermophysics ndash 1991 ndash Vol 60 3 ndash P 419-425
14 Zhavrin YuI Kosov VN Kullsquozhanov DU and Karataeva KK Experimental determination of the
boundary of monotonic disturbances upon instability of the mechanical equilibrium in three-component
gas mixtures Journal Engineering Physics and Thermophysics ndash 2002 ndash Vol 75 4 ndash P 80-83
15 Zhavrin YuI Kosov VN and Krasikov SA Some features of convective heat and mass transfer in
multicomponent gaseous mixtures Journal Engineering Physics and Thermophysics ndash 1996 ndash Vol
69 6 ndash P 977-981
16 Trengove R D Robjohns H L Martin M L Dunlop Peter J The pressure dependences of the
thermal diffusion factors of the systems He-Ar He-CO6 at 300 K Physica A ndash 1981 ndash Vol 108
Issue 2-3 - P 502-510
17 Trengove R D Robjohns H L Bell T N Martin M L Dunlop Peter J Thermal diffusion factors
at 300 K for seven binary noble gas systems containing helium or neon Physica A ndash 1981 ndash Vol
108 Issue 2-3 - P 488-501
18 Zhavrin YuI Kosov ND Belov SM Tarasov SB Pressure effects on diffusion stability in some
three-component mixtures JTechPhys ndash 1984 ndash Vol 54 5 ndash P934 ndash 947
19 Hirschfelder JO Curtiss ChF and Bird RB Molecular theory of gases and liquids ndash University of
Wisconsin 1954 ndash 932 p
20 Trengove R D Harris K R Robjohns H L Dunlop Peter J Diffusion and thermal diffusion in
some dilute binary gaseous systems between 195 and 400 K Tests of several asymmetric potentials
using the infinite order sudden approximation Physica A ndash 1985 ndash Vol 131 Issue 3 - P 506-51
Heat Physics Hydrodynamics Energetic 23
UDC 5301
NONLINEAR FRACTALS AND EXCITON FORMATIONS IN NANOSTRUCTURED
SEMICONDUCTORS
ZZh Zhanabayev TYu Grevtseva
Al-Farabi Kazakh National University Tole bi Street 96 050012 Almaty Kazakhstan mptllistru
We suggest the fractal model for the description of exciton spectra in amorphous and porous
semiconductors Because of theirs chaotic structure the well-known analogy of exciton with
hydrogen-like atom is insufficient
We obtain equations for energy of exciton biexciton and trion depending on photon energy
Comparison of results of our theory to the recent experimental data is given in the paper Theory
shows the existence of most universal regularities of dynamical systems
Keywords fractal model exciton exciton spectra semiconductors photon energy
Introduction
Excitons and exciton formations such as biexcitons and trions can be used for distinguishing
quick-changing information signals So excitons are the subject of many studies on
nanoelectronics Overlapping of wave functions of electrons and holes is probable in nanoclustered
semiconductors Therefore exciton binding energy in such semiconductors is greater than in
infinitely homogeneous medium These facts suggest a possibility of generation of excitonic
quantum bits at sufficiently great even at room temperatures
Generally due to the specific character of technology processes (implantation diffusion-
limited aggregation) nano-sized semiconductors have irregular chaotic structure Here such
semiconductors characterized by fractal regularities though on a small range of scale of
measurements Therefore properties of excitons canlsquot be described universally via smooth
regularities which follow for example from differential equations So a common analogy between
exciton and hydrogen-like atom canlsquot be used for a full description of specifics of excitonic spectra
in noncrystalline semiconductors with chaotic structure [1]
Such conclusion follows also from experimental works [2 3] devoted to the description of
some self-similarity quantum-mechanical coherence and decoherence between an exciton and
biexciton Therefore we put the natural question whether energy exciton spectra have properties of
fractal curves
The aim of this paper is to develop the new model due to describe nonlinear fractal evolution of
excitons in dependence upon stimulating photon energy and comparison of results with available
experimental data
Nonlinear fractal measures
The main properties of fractals are their self-similarity and dependence of measure on scale of
measurements We mean that measure is a physical value which can be characterized by additive
measurable set For example measures of a geometrical fractal are its length square and volume
Nanoobjects have surprising variety of physical properties because their measures depend on their
values according to nonlinear laws This fact brings out clearly to necessity of fractal analysis in
nanoscience
By use of well-known theories of fractals we choose minimal scale of measurement (size of
cells covering an object) independently on value of defining measure For the description of
evolution of measure in dependence upon given parameter of order which is determining variable of
a physical process we choose the scale of measurement via this parameter and desired measure
Hence fractal measure is a nonlinear function depending on the process
24 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The traditional definition of fractal measure M can be written as
0 0M M M M D d
(1)
where 0M is a regular (non-fractal) measure M is a scale of measurements
M is norm of
M D is fractal dimension of the set of values of M d is topological dimension of norm carrier
M is independent on M therefore measure defining by (1) can be tentatively called the linear
value
If parameter of order is we can choose M as
1 1 M
M M MM M
M M
(2)
where indexes M and correspond to the norms M According to (2) we can rewrite the
formula (1) as
0 01 1 M
MM M M M
M
(3)
At 0 we have 0MM M M it corresponds to the meaning of
0M At 0 we have
0MM M 0M It means that the fractal measure defined by its own norm exists in a case
when external influence characterized by parameter is absent
We apply the equation (3) for the description of excitonic spectrum Let us suppose that we
have an electron in conduction band and a hole in valence band in a semiconductor Band gap is
gE effective mass of electron is em effective mass of hole is hm The rest particles produce a
background with dielectric capacitivity We consider that interaction between these two quasi-
particles occurs according to Coulombs law So by using Schroumldinger equation for hydrogen atom
we can obtain the equation for full energy of electron-hole pair
42 2
2 2 2 123
2 2
e hn g
e h e h
m m eh kE k E n
m m n m m
(4)
We shall not take into account energy of motion of exciton ―as a whole Thus exciton
quasi-momentum k
is equal to zero Let us designate binding energy of electron and hole in
exciton (the last term in equation (4)) as E We shall consider a case of excitation of electron by
photon with energy w sufficient for electron transition to valence band So we can rewrite
equation (4) as
gw E E (5)
Using new simplified designations 1MM M E
0 0M E gw E
1wM E from
equation (3) we obtain the equation for energy of single exciton 1E
1
1 0 0 1 1 0 0 1
1
1 1 g w
w w w w
g
w E EE E f E E E E f E E
E w E
(6)
Here 0E is exciton energy at excitation threshold by photon with
gw E In this case
0 0wE
Biexciton trions and other clusters can be described via hierarchical structures
0
0
(7 )
12 (7 )
n n
w
n w n w
EE f f E a
n
EE f f E n b
n
Heat Physics Hydrodynamics Energetic 25
where number of brackets is equal to n Equation (7a) corresponds to choosing of scale of
measurements of fractal measure relative to the measure and describes evolution of excitons
biexcitons and other structures existing in a ground state ie without of external radiation Equation
(7b) corresponds to choosing of scale of measurements of fractal measure relative to photon energy
and describes excited states Equations (6) (7а) (7b) determines energy of system which consists
of exciton formations
1
12n
i
i
E E n
(8)
Here 1n describes an exciton 2n ndash biexciton 3n ndash trion and so on
In the simplest case in semiconductors with intrinsic conductivity absorption coefficient is
defined via density of number of states which is proportional to the square root of energy
0w const E E (9)
Coherence and decoherence described in experimental works [2-4] It is possible to draw a
conclusion about presence of coherence by examination of instantaneous phase and corresponding
frequency Instantaneous phase ( )t of a signal )(tx can be described via standard Hilbert
transform as
( ) 1 ( )( ) ( )
( ) -
HHx t x
t arctg x t dx t t
(10)
Mean ―frequency along the intervals of w is defined as
d wF
d w
(11)
Results of the numerical analyses
Let us consider exciton-biexciton spectra described by equations (6)-(8) in nanostructured
semiconductor films Varying the parameters gE 0E it is possible to obtain different types of
exciton spectra
(a)
(b)
Fig 1 Influence of parameter on the exciton-biexciton spectrum (a) ndash equation (7a) (b) ndash equation
(7b) 0 2 116 005 1 1 2 1 gE eV E eV I I
26 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
(a)
(b)
(c)
Fig 2 Exciton-biexciton spectrum (a) module of phase (b) and mean frequency (c)
0 216 005 1 gE eV E eV I
Fractality leads to increasing of amplitude of oscillations and extending of spectra (Figure 1)
We used self-similar ( 21 I ) and self-affine ( 11 I ) values of fractal dimensions [1] Increasing of
energy gap width gE leads to the shift of oscillation region towards greater values of photon
energy
We can strictly distinguish regions of exciton and biexciton oscillations (big and small
oscillations) It is possible by use of terms ―phase - frequency (Figure 2) It confirmed the presence
of coherence We define coherence as some phase difference between regions of oscillations of
exciton and biexciton Location of peaks and their number inside of these regions depend on and
number of points used for simulation Figures 2 were obtained with the step 310w eV
Comparison of theoretical results to experimental data
Figure 3(a) shows exciton-biexciton spectrum of a quantum dot recorded at 4 K [2] The
quantum dot was fabricated on a GaAs(311) substrate by metalorganic vapor epitaxy The quantum
dot is a self-assembled quantum dot Each peak of photoluminescence (PL) spectrum corresponds to
an excited state of exciton or biexciton Figure 3(b) illustrates the exciton-biexciton spectrum
which was calculated by equations 7(а) (8) and (9)
Heat Physics Hydrodynamics Energetic 27
(а)
(b)
Fig 3 Exciton-biexciton PL spectrum from an isolated InGaAs quantum dot Experimental data [2] (a)
results of numerical analyses (b) 16 0244gE eV 4
0 005 10 E eV w eV
Figure 4(a) shows experimental exciton PL spectrum from InGaAs quantum dots fabricated by
metalorganic vapor epitaxy [3] The sample has two quantum dot layers Separation between each
layer is about 5 nm Figure 4(b) shows result of simulation by equations 7(а) (8) and (9) (а)
(b)
Fig 4 PL spectrum from bilayer InGaAs quantum dots Experimental data [3] (a) results of numerical
analyses (b) 2165 1 gE eV I 3 4
0 4 10 10 E eV w eV
Discussion
Shift of exciton and biexciton spectra by photon frequency is observed in theoretical figures
Exciton peaks in theoretical curves are seen in ranges of 2 310 10w eV These facts
correspond to experimental data If we choose 0 gE E according to the conditions of experiment
then we have good agreement between theoretical and experimental results Amplitudes of exciton
spectra and spectra of excitonic formations correspond to experimental data Threshold energy 0E
which need to formation of exciton depends on character of localization of nanostructures and
temperature Meaning of 0E is maximal phonon energy Exciton destructed if phonon energy is
greater than 0E
It is worthy of notice that in experiment [2] biexciton forms around of quantum dot Region of
its localization it not limited artificially Biexciton can be formed between two quantum dots [3]
28 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Distance between quantum dots is about 5 nm ie strong localization stimulates formation of
exciton at small 0E These facts correspond to the theory
So fractal model of the dependence of electron-hole pair energy on energy of exciting photon
can be used for the description of coherence between exciton formations The terms ―quantum-
mechanical coherence and ―coherence of wave processes of different nature have diverse
meanings Quantum-mechanical coherence means the time interference between wave functions
only It appears as energy oscillations in a system Generally coherence means that phase
difference is stable by some determining variables at subsystem evolution In excitonic formations
coherence can be observed in these different types
Conclusions
In the present work we suggest the new equation for fractal measure depending on itself and
scale of measurements This measure correctly describes a hierarchy of excitonic formations The
theory describes conditions for initiation of oscillations and for energy peaks coherence of exciton
formations These new ideas can find wide applications in modern nanoelectronics
References
1 Zhanabayev ZZh Grevtseva TYu Fractal Properties of Nanostructured Semiconductors Physica B
Condensed Matter ndash 2007 - Vol 391 1 - P 12-17
2 Gotoh H Kamada H et al Exciton Absorption Properties of Coherently Coupled Exciton-Biexciton
Systems in Quantum Dots Phys Rev В 71 ndash 2005 ndash PP 195334-1 ndash 9
3 Gotoh H Sanada H Kamada H Nakano H Hughes S Ando H Temmyo J Detecting Coupled Excitons
with Microphotoluminescence Techniques in Bilayer Quantum Dots Phys Rev В 71 ndash 2006 ndash PP
115322-1 ndash 6
4 Kamada H Gotoh H Temmyo J Takagahara T Ando H Exciton Rabi Oscillations in a Single Quantum
Dot Physical Review -Vol 87 No 24 ndash 2001 ndash PP 246401-1 ndash 4
Heat Physics Hydrodynamics Energetic 29
UDC 53254
HYDRODYNAMICS OF HYDROCYCLONE WITH BUILT-IN WATER INJECTOR
1L Minkov 2M Farghaly 3J Dueck
1Tomsk State University Tomsk Russia
2Al-azhar University Egypt
3Friedrich-Alexander-University Erlangen-Nuremberg Germany lminkovftftsuru
The paper considers the numerical simulation of 3D fluid dynamics based on the k-eps RNG
model of turbulence in the hydrocyclone with the injector containing 5 tangentially directed
nozzles The simulation results are supported by experimental research It is shown that the
direction of movement of injected fluid in the hydrocyclone depends on the water flow rate through
the injector Experiments and calculations show that the dependence of the Split-parameter on the
injected water flow rate has a non-monotone character associated with the ratio of power of the
main flow and the injected fluid Keywords numerical simulation hydrocyclone injector injected fluid water flow rate split-parameter
Introduction
The basic separation principle employed in hydrocyclones which are widely used in different
fields of engineering applications is the centrifugal sedimentation Feed slurry is introduced under
pressure via the tangential inlet and is constrained by the geometry of the unit to move into a
circular path This creates the outward centrifugal force and the convective flux of particles toward
the wall
In spite of its simple configuration the hydrocyclone has a complex flow field The
characteristics of the hydrocyclone flow are as follows very strong circulation complex turbulent
fields formation of closed circulation zones and formation of the air core near the central axis
zone
Turbulent diffusion prevents fine particles to accumulate near the wall of hydrocyclone and
even leads to make them spreads over the whole space of the hydrocyclone In case of neglecting
the influence of the centrifugal force on the fine particles they will leave the hydrocyclone
proportionally to the quantities of water flowing out through both outlets
Many researchers [1-9] were interesting to study the hydrocyclone hydrodynamics
(computational mathematics) that theoretically and experimentally revealed basic characteristic
features of hydrocyclone flow while other studies were focusing on the technological aspects of the
solid-liquid separation or size classification [10 ndash 15]
The typical disadvantages of hydrocyclone operation can be summarized as follows
incomplete separation of solid phase especially the fine fractions insufficient quality of the
separation and the relatively small value of cut size These disadvantages can be partially
eliminated by changing the design parameters of the hydrocyclone or by variation of the
hydrocyclone feed pressure Changing the hydrocyclone configuration to improve the separation
and classification processes have been undertaken for a sufficiently long time
One of these techniques is the water injection into the conical part of the hydrocyclone [16 ndash
21] Recently a new water injection hydrocyclone which is characterized by the injection in the
lowest possible position near the hydrocyclone apex is developed and is schematically shown in
Fig1 A simplified mathematical model of classification in a hydrocyclone is presented in [22]
Further development requires a deep knowledge of hydrodynamics in the hydrocyclone with the
injector
30 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
A B
C D
E F
A B
Fig 1 Scheme of hydrocyclone and water injector
Water injection is expected to wash out the fine particles from the wall boundary layer to the
axis where particles are swept up by upward flow and then discharge through the overflow
Accordingly fine particles missreported through the underflow discharge will be decreased
The effect of the injection depends on many parameters such as the amount of injected water
the injection velocity the position of injection and many other parameterswhich should be
optimised Besides the experimental investigations the modelling processes of the injection is of
great importance to describe the injection mechanism Models describing the influence of water
injection on the separation efficiency of dispersed material have found not enough in the literature
till now Such models could be created on the base of appropriated investigations of the
hydrodynamics but the hydromechanics of flow in case of water injection hydrocyclone is not
described in the literature
Modeling the hydrodynamics in hydrocyclone with water injector supported by experiments is
the aim of this work Special emphasis were focused on to explain the mechanism of injection and
its influence on the variation of fluid flow field and hence on the classification mechanisms
Experimental test rig and procedures
The test-rig used in the experimental work consisted of a 50-mm water injection cyclone
positioned vertically above a feed tank (Fig 2)
Heat Physics Hydrodynamics Energetic 31
Fig 2 Water injection hydrocyclone test rig 1 ndash Water injection cyclone 2 ndash Injector 3 ndash Feed slurry
tank 4 ndash Control valves 5 ndash Pressure gauge 6 ndash Manometer 7 ndash Pump
The outlet of the pump is connected to the hydrocyclone feed inlet A by-pass pipe with a
control valve was connected to the outlet line to obtain the desired pressure drop inside the cyclone
A pressure gauge was fitted near the feed inlet to indicate the pressure drop The water injection
cyclone which is used through this work is a conventional hydrocyclone with a modified conical
part with water injection facility
The water injection assembly consists of an outer solid ring and inner solid ring with 5 inlet
openings at equal distances opened directly on the periphery of the cone part as shown in Fig 1
This assembly is connected with water control valve through which the water can be supplied under
pressure in the assembly and injected through these openings A digital flowmeter was fixed near
the water injection to indicate the water injection rate
The injection ring was designed to permit the water to be injected in a tangential direction with
the same swirling direction as the main flow inside the hydrocyclone The ring when attaches to the
cone part will have the same internal geometry of it without any mechanical parts to be inserted
inside the cone part to avoid any mechanical disturbing of the flow inside the hydrocyclone The
water injection part was added near the apex of the cyclone without causing any extension of the
total cyclone length
A pre-selected vortex finder and apex were fitted to the body of the water injection cyclone and
then the feed is pumped at the required inlet pressure The steady state is reached through nearly
one minute
To investigate the effect of water injection rate on the hydrodynamics of the separation
samples were taken at different flow rates of injection From these samples the feed flow rate
overflow rate and underflow rate can be calculated at every test from which the split - parameter
can be estimated
32 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Numerical model
The geometry of the hydrocyclone is given in Fig 3 The grid for a discrete description of flow
field was realized with the help of a computer software (Gambit 2316 Fluent Inc copy) to create the
3D body fitted grid of 170000 cells Calculation of hydrodynamics was done on the base of Fluent
6326 software
The set of Navier-Stokes equations includes
Continuity equation
0x
u
i
i
321i
Momentum equation
j
ieff
jij
ji
x
u
xx
p
x
uu
321ji
dinj hinj
z = 0
hinj dinj
Dc 50 mm
Din 145 mm
Do 16 mm
Du 6 mm
L1 130 mm
L2 350 mm
L3 135 mm
l1 + l2 79 mm
l2 37 mm
l 8 mm
dinj 25 mm
hinj 20 mm
Fig 3 Geometry of water injection hydrocyclone
The RNG k model of turbulence [23] is used to calculate effective
viscosity tmoleff
The turbulence kinetic energy equation
k
j
effk
ji
i Gx
k
xx
ku
The dissipation rate of turbulence kinetic energy equation
2k1
j
eff
ji
i CGCkxxx
u
Heat Physics Hydrodynamics Energetic 33
Knowing values of the turbulence kinetic energy and its dissipation rate one can calculate the
value of turbulent viscosity as follows
kf
kC s
2
t
Where
kf s
= the correction function taking into account a swirling flow [FLUENT 63
Users Guide Fluent Inc 2006-09-20- 2006] 2
tk SG ijijSS2S
Where
ijS = mean rate-of-strain tensor
j
i
i
j
x
u
x
u
2
1 3
0
3
221
1CCC
Where
k
S
Model constants
3931k 150s
0120 421C1
08450C 3840
Boundary conditions
a) At the inlet of main feed pipe
Normal component of inlet velocity 2
4
inlet
inlet
nD
Qu
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inlet
2343
D070
kC
Where
inletD = diameter of feed pipe
inletQ= volumetric flow rate at the inlet of main feed pipe
b) At the inlet of injector feed pipe
Normal component of injection velocity 2
inj
inj
nd
Q4u
Tangent component of inlet velocity 0u
Turbulence kinetic energy 2n
2 u102
3k
Dissipation rate of turbulence kinetic energy inj
2343
d070
kC
Where
injd = diameter of injector pipe
injQ= volumetric flow rate at the inlet of injector pipe
c) On the injector and hydrocyclone walls
No-slip conditions were chosen 0u i
34 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
d) At the outlets
The ambient pressure was applied in the centre of the upper flow and underflow outlets and the
condition of equilibrium of the centrifugal forces with the radial pressure gradient was used in the
internal points of the outlets
r
u
r
p 2
The set of equations (1) - (4) was numerically solved using the upwind differential scheme of
second order of accuracy for convective terms and the second order of accuracy for pressure
gradients SIMPLEC was used for the pressure-velocity coupling
Results and Discussion
1 Stream lines and velocity fields
The flow field of fluid in the conical part of hydrocyclone on the section included the axis of
cyclone and the straight line AB is showed in Fig 1 above the injector and is depicted in Fig 4 (y =
0 z = - 0341 m) It should be noted that using of 5 injectors tubes leads to asymmetrical profiles
of velocities
а)
b)
y
x
-12 69 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
6 ms
y
x
2 ms
Heat Physics Hydrodynamics Energetic 35
c)
Fig 4 Flow fields above the injector (z = - 0341 m) Qfeed= 6362 lmin а) Qinj= 0 lmin b) Qinj= 4
lmin c) Qinj= 9 lmin
In the calculations and the subsequent presentation of the results a rectangular coordinate
system was used Coordinate x is measured along the line AB as shown in Fig 1 and the coordinate
z is measured along the axis of the hydrocyclone beginning with the transition cross section of the
cylindrical part of the hydrocyclone in a conical one as shown in Fig 1
In case of no injection the increased velocity zone directed to the apex takes place near the
axial domain (Fig4 а) The velocity profile at low values of injection rate (Qinj= 4 lpm) becomes
flat (Fig4 b) whereas at high values of injection rate (Qinj=9 lpm) the reorganization of flow field
takes place near the wall of hydrocyclone zones of flow inverse directed to the main one are
formed (Fig4 b) Similar conclusions can be made by analysis of Fig5
а) b) c)
Fig 5 Trajectories of fluid Qfeed=6362 lmin а) Qinj=0 lmin b) Qinj=4 lmin c) Qinj=9 lmin 1 ndash
Trajectory of fluid particle leaving the hydrocyclone through the upper outlet 2 ndash Trajectory of fluid
particle leaving the hydrocyclone through the down outlet
x
-1269 mm
-9469 mm
-17669 mm
-25869 mm
-34069 mm
y
6 ms
36 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 5 shows the swirling trajectories of the injected liquid for nonzero rates 4 lpm (Fig 5 a)
and 9 lpm (Fig 5 b and Fig 5 c) At low injection rate (Qinj= 4 lpm) most of the injected water is
entrained by the main flow and leaves the hydrocyclone through the underflow which leads to the
increasing the water discharge through the underflow
At high injection rate (Qinj = 9 lpm) in Fig 5b one can see the trajectories of injected fluid are
both upward and downward This means that the injected liquid can be entrained by two streams
and can be removed from the apparatus through the both outlets It is interesting to note that at this
injection intensity (Qinj = 9 lpm) among trajectories initially directed upwards there are those which
at a certain height relative to the injector are fully turned and finish at the underflow apex (Fig 5 c
trajectory 2)
2 Velocity components
The following results were picked up on the section included the axis of apparatus and the
straight line AB showed in Fig 1 Along this line is the x-coordinate which intersected with the
axis of apparatus (axis of hydrocyclone)
21 Axial velocity
The profiles of the axial velocity are shown in Fig 6 The axial velocity above the position of
the injector is shown in Fig 6a while the axial velocity under the position of the injector is shown in
Fig 6b At low injection rate the power of injected water is small to overcome the resistance of the
main flow Additional resistance created by the injected water results in the stagnation of main
flow near the injector All flux from the injector directs to the underflow that leads to the increase
in the axial velocity of flow into the apex
At injection with flow rate equal to 4 lpm all the liquid flowing through the inlet leaves the
hydrocyclone either through the overflow or through the underflow while the injected liquid flows
only through the underflow When Qinj = 9 lpm the power of injected jet is enough to overcome the
resistance of the main flow and the injected liquid flows both through the underflow and through
the overflow while the liquid fed through the inlet flows through the underflow discharge
At high injection rate the upward swirling flow along the wall of cone part of hydrocyclone is
formed upstream At the zone near the axis the downward swirl rotating co-axial with the outer
vortex is developed
The three minima presented in the velocity distribution in Fig 6b can be explained by the
presence of two whirls present in this part of the apparatus one is formed on the periphery as a
result of the liquid which comes directly from the injector to the apex the other central whirl
formed by a liquid which is carried away from the injector upwards which is braked as a result of
interaction with the main downwards stream
Fig 6 Dependence of axial velocity distribution of a transverse coordinates x at various velocities of
injected water Qinj a) Z=0341 m (above the injector position) b) Z= 0350m (under the injectors
position)
Heat Physics Hydrodynamics Energetic 37
22 Tangential velocity
Fig 7 shows the distribution of the tangential velocity This velocity component as a source of
centrifugal force affects critically the classification performance
In Fig 7 a mild injection leads to a reduction in the tangential velocity on the periphery of
liquid (at 4 lpm) Increasing of the injected velocity leads to an increase in the tangential component
of flow Thus the tangential velocity increases in the whole flow (at 9 lpm) Near the axis zone the
velocity distribution of rotating flow is similar to the velocity distribution of a solid body (profiles
tangential velocities are close to straight lines) Towards the periphery the velocities profiles
change the sign of their second derivative which showed as stated previously the existence of
internal injector swirl rotating at a velocity different from the velocity of the external vortex
Fig 7b shows the tangential velocity profiles at the position under the injectors at different
velocity of injected water At low injection velocity of 4 lpm only weak changes are occurred at
the profile tangential speed below the injector while at high injection speed of 9 lpm the velocity of
the flow near the wall of apex is increased
Fig 7 Profiles of tangential velocity a) above the injector (Z= 0341 mm) b) below the injector
(Z= 0350 mm)
23 Radial velocity
A strong restructuring of the profile of the radial velocity occurs above the injector (Fig 8a)
Fig 8 Profiles of radial velocity a) over the injector (Z= 0341 m) b) under the injector (Z= 0350 m)
Arrows indicate the direction of the radial velocity at 90 lpm
In case of no injection the fluid is directed from the axis to the walls (solid curve at Qinj=0)
The curves are rather symmetrical relatively to the z-axis The positive values of radial velocity
at xgt 0 indicate the movement from the axis to the wall as negative for xlt0 The low injection
38 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
velocity reduces the radial velocity and changes its direction to the opposite from the periphery to
the center (the curve at Qinj=4 lpm) At high injection rates there is a non monotone and
asymmetrical profile of radial velocity (curve at Qinj=4 lpm) Near the axis the flow is directed to
the periphery of the axis while near to the walls the motion may be directed inward (the left part
profile) and outside (the right side profile) Under the injector (Fig 8b) the radial velocity is
directed mostly to the wall The radial velocity is rather weaker in comparison with the case without
injection
3 Pressure
Increasing the injected water generates upwards flow which forms additional hydraulic
resistance Consequently the pressure in the inlet increases according to adjusted constant flow rate
of water
Fig 9 shows the calculated increase in the pressure values at the feed inlet with increasing of
the injected liquid velocity (under condition that the feed throughput is constant) This should be
taken into account during the experiments Such increase of pressure in the feed is observed during
the experiments and requires readjusting the pressure if a constant pressure is desired The
dependence of the pressure increase on the rate of injection is describing well by the power
dependence with an exponent approximately equal to 13
y = 00102x1312
0
005
01
015
02
025
0 2 4 6 8 10
Winjmsec
P
Fig 9 Dependence of feed pressure on the injected water velocity
4 Ratio of flow rates at outlets
The split-parameter (S) which is defined as the ratio of water flows through both output
openings of apparatus (overflow and underflow water) is of great importance to the separation
process and can be given as follows
un
ov
Q
QS
The fine particles are divided proportional to the ratio of water flows through these outlets For
conventional hydrocyclone (without injection) the split parameter increases if the feed pressure
increases as it is shown in Fig 10 This trend is agreed with the investigations of Bradley [24]
while it is contradicts to the work of Tarjan [25]
Heat Physics Hydrodynamics Energetic 39
4
5
6
7
8
9
10
11
12
0 5 10 15 20
Qinj lmin
Qu
n lm
in
P=08 bar P=10 bar
P=15 bar P=20 bar
calc P=08 bar calc P=15 bar
Fig 10 The volumetric flow rate through the underflow discharge as dependent on the injection velocity
(Symbols and solid curves are the experimental data dashed ones are the calculations)
Herewith at constant feed pressure the effect of injection velocity on the split parameter (S) is
investigated Experiments have showed that the increase in injection velocity at low values (up to 5
lpm) leads to an increase in the fluid flow through the underflow while at high velocity values it
leads to decrease in the underflow throughput as seen in Fig 10 The same trend was also obtained
from the modeling calculations as shown in Fig 10
Fig 11 shows the change of the split parameter related to throughput of the injected water
( injQ ) at different feed pressure values From this figure it can be seen that the estimated numerical
values of the split parameter injQS are agreed qualitatively well with the experimental data The
split parameter injQS decreases gradually by increasing injQ in a small range Further increase of
injQ leads to gradually increase of the split-parameter injQS values So it can be concluded that the
trend of the split-parameter curve as a dependent on injQ is non monotone
Fig 11 Effect of the injection throughput on the split parameter
40 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Discussion
Injection of water through the hydrocyclone may significantly change the hydrodynamic field
in the apparatus This change is particularly strong near the injection inlets The present work
examined the impact of tangential injection of water through the injector located at the bottom of
the conical part of the hydrocyclone The influence of tangential injection is found to be the highest
hydrodynamic impact on the classification process
The calculation results have showed that the injection influence is not only due to the change of
radial velocity component as it was supposed ie carrying out the particles from near the wall zone
into the axis region and then to be separated in the overflow outlet This can be shown apparently
from Fig 8 where the radial velocity changes its sign (radial speed changes its direction) at
intervals along radial coordinate from the axis towards the wall
The other reason which could be more possible to explain the injection effect is by considering
the mechanism influencing the particles (if they would be in a flow) that is connected with the
change of the axial component as follows
A powerful stream of liquid arises upward during enough strong injection at the conical wall of
the hydrocyclone should move out the particles upwards specially the fines up to the cylindrical
part of the cyclone Some of these particles which follow the flow lines as it is shown in Fig 5 will
be directed to the overflow another will return downwards again and be compelled to undergo
again through the hydrodynamic influence of injector
Apparently that probability of such particles to be transported through the underflow discharge
is much lower in comparison with similar probability for particles which do not be influenced by
injected jets
This circumstance well proves to be true in experiments [16 ndash 21] where significant decrease
of values of the separation function (analogue of discussed probability of carrying out the particles
through the apex) for fine particles was observed
Concerning the effect of the tangential velocity the results have showed that the increase of
injection throughput leads to a growth in the centrifugal force (tangential velocity component) This
force affects on the particles and brings them out towards the hydrocyclone wall It is known that
the larger are the particles the higher is the effect Thus for fine particles the increase in tangential
velocity practically will not cause any effect while the coarse particles should leave more
effectively to a wall and finally to apex
The presented calculations show that the influence of injection on the flow in the hydrocyclone
is affected by alteration the velocity field by injected water At low water injection rate the injected
tangential water slows the mean stream especially its tangential component (Fig 7) but at high
injection speed it accelerates the tangential component This complex influence of injection affects
dependence on the distribution of quantity of injected water between both outlets (overflow and
underflow)
Experiments and calculations showed a non monotonous change of a portion of the injected
water which goes through the underflow discharge This explains the change of the influence
mechanism of the injected water on the main flow
Conclusions
The influence of tangential water injection through an injector located at the conical part just
above the apex on the mean stream in a hydrocyclone is investigated The injection of water in a
hydrocyclone can markedly change the hydrodynamic fields in the device
On the basis of the calculations partially supported by measurements the explanation of the
mechanism of influence of an injector on separation characteristics of a hydrocyclone is presented
The mechanism is based on the generation of the axial streams which have been directed
upwards that leads the recirculation of particles in the device and to lowering of value of probability
for fine particles to be transported through the underflow discharge
Heat Physics Hydrodynamics Energetic 41
At low water injected rates the mean stream is broken but at high ones it is accelerated It
leads to non monotone dependence of a fraction of the injected water allocated through the
underflow aperture
References 1 Pericleous KA Rhodes N ―The hydrocyclone classifier ndash a numerical approach International Journal of
Mineral Processing Vol 56 pp 23-43 1986
2 MR Davidson ―Simularity solution for flow in hydrocyclones Chem Eng Sci 43 (7) pp 1499-1505
1988
3 K T Hsien RK Rajamani ―Mathematical model of the hydrocyclone based of fluid flow AIChE J 37
(5) pp735-746 1991
4 Monredon TC Hsien KT and Rajamani RK ―Fluid flow model of the hydrocyclone an investigation of
device dimensions International Journal of Mineral Processing Vol 35 pp 65-83 1992
5 TDyakowski RA Williams ―Modelling turbulent flow within a small-diameter hydrocyclone Chem Eng
Sci 48 (6) pp 1143-1152 1993
6 P He M Salcudean IS Gartshore ―A numerical simulation of hydrocyclones Trans Inst Chem Eng J
Part A 7 pp 429-441 1999
7 G Q Dai JM Li WM Chen ―Numerical prediction of the liquid flow within a hydrocyclone Chem
Eng J 74 pp 217-223 1999
8 Novakowski A F Kraipech W Dyakowski T and Williams RA ―The hydrodynamics of a
hydrocyclone based on a three-dimensional multi-continuum model Chem Eng J Vol 80 pp 275ndash282
2000
9 J Ko S Zahrai O Macchion H Vomhoff ―Numerical modeling of highly swirling flows in a through-
flow cylindrical hydrocyclone AIChE Journal 52 10 pp 3334 ndash 3344 2006
10 Nowakowski J C Cullivan R A Williams and T Dyakowski ―Application of CFD to modelling of the
flow in hydrocyclones Is this a realizable option or still a research challenge Minerals Engineering Vol
17 Issue 5 pp 661-669 May 2004
11 Dueck J Matvienko OV and Neesse Th ―Modeling of Hydrodynamics and Separation in a
Hydrocyclone Theoretical Foundation of Chemical Engineering Kluver AcademicPlenum Publishers Vol
34 No 5 pp 428-438 2000
12 Narasimha M Sripriya R Banerjee P K ―CFD modelling of hydrocyclone- prediction of cut size
International Journal of Mineral Processing Vol 75 pp 53-68 2005
13 SSchuumltz M Piesche G Gorbach M Schiling C Seyfert P Kopf T Deuschle N Sautter E Popp T
Warth ―CFD in der mechanischen Trenntechnik Chemie Ingenieur Technik 79 11 pp 1777 ndash 1796 2007
14 Neesse T and Dueck J ―Dynamic modelling of the hydrocyclone Minerals Engineering Vol 20 pp
380-386 2007
15 Neesse T and Dueck J ―CFD ndash basierte Modellierung der Hydrozyklonklassierung Chemie Ingenieur
Technik 79 11 pp 1931 ndash 1938 2007
16 Heiskanen K ―Particle Classification Chapman and Hall LondonndashGlasgowndashNew YorkndashTokyondash
MelbournendashMadras 321 pp 1993
17 DD Patil TC Rao Technical Note ―Classification evaluation of water injected hydrocyclone Mineral
Engineering Vol 12 no 12 pp 1527- 1532 1999
18 DF Kelsall JA Holmes ―Improvement in classification efficiency in hydraulic cyclones by water
injection In Proc 5th Mineral processing Congress Paper 9 Inst Of Mining and Metallurgy pp 159-170
1990
19 RQ Honaker AV Ozsever N Singh B K Parekh ―Apex water Injection for improved hydrocyclone
classification efficiency Mineral Engineeering Vol 14 No 11 pp 1445- 1457 2001
20 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao TC Rao ―Modelling studies on a 100 mm
water-injection cyclone Physical Separation in Science and Engineering September-December Vol 13
no 3-4 pp 89 ndash 99 2004
21 K Udaya Bhaskar B Govindarajan JP Barnawal KK Rao BK Gupta TC Rao ―Classification studies
of lead-zinc ore fines using water-injection cyclone Intern Journ Mineral Processing 77 pp 80-94 2005
22 JG Dueck EV Pikushchak and LL Minkov ―Modelling of change of the classifiers separation
characteristics by water injection into the apparatus Thermophysics and Aeromechanics Vol 16 No 2
pp 247-258 2009
23 Yakhot V Orszag SA Thangam S Gatski TB amp Speziale CG ―Development of turbulence models
for shear flows by a double expansion technique Physics of Fluids A Vol 4 No 7 pp1510-1520 1992
24 Bradley D ―The Hydrocyclone Pergamon Press London 1965
25 Tarjan G ―Some theoretical questions on classifying and separating hydrocyclones Acta tech Acad Sci
32 pp 357 ndash 388 1961
42 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 534185172
THE RESULTS OF ldquoVIBRATION-SEISMIC-MODULE-SOLID MASSIF-DISTURBANCErdquo
SYSTEM SIMULATION MODELING
Y M Smirnov BM Kenzhin MA Zhurunova
Karaganda State Technical University Kazakhstan Karagandy smirnov_y_mmailru
Paper is devoted to study of interaction of a mechanic harmonic generator ndash the vibration-
seismic module - and a coalbed As a result there are qualitative and quantitative dependences of
distribution of elastic seismic ostillations in a coalbed
Keywords mechanic harmonic generator massif elastic seismic ostillations massif particlesrsquo dislocation
In the result of complex analytical and experimental research dedicated to the development of
adaptive method of impact onto the coal solid massif as well as due to the outcomes of
determination of internal parameters and output indicators of vibration hydraulic executive elements
and parameters of their interface with the massif there had been analytical dependences and its
graphical interpretations defined that shall be verified for compliance to field values [1]
Since the experimental research under mining environment sets forward particular difficulties -
quite sufficient and frequently justified due to production conditions - there had been computer-
based experiment fulfilled This type of approach for development of new techniques and
technologies across various industries is not deemed brand new
The nature of the research is as follows
To enable experimental verification of the theoretical results there had been ANSYS licensed
computer application package used [2] Simulation modeling of major elements interfacelsquos dynamic
processes examined both theoretically and experimentally is targeted to provide vivid possibility to
determine optimal and efficient parameters of ―module-solid massif-disturbance dynamic system
avoiding expensive experiments and using calculative approach
ANSYS licensed computer application includes variety of extensive capabilities such as pre-
processor solid modeling strength heat magnet hydraulic and combined types of calculations
processor elaboration of the results and their graphical interpretation The model data (including
geometry description final elementslsquo decomposition materials etc) are recorded in the database
by means of ANSYS processor
The solver works directly with the information that is stored in the database and then records
the results in the same database All of the data required for the calculation are set in the course of
pre-processor treatment stage There is a possibility to select the end element type to input
material properties create solid models and decompose them onto elements as well as to set the
required boundary conditions
Upon completion of model development the type and parameters of the required analysis
load and its options shall be set The indicated type of analysis shows which equations will be
used to deliver the solution In the course of pre-processor treatment stage there shall be results
processing actions performed provided the results used are those obtained during solution
delivery they may include dislocations temperatures voltage deformation speed etc
The results may be presented graphically or in tables ANSYS software owns powerful
geometrical modeling subsystem that creates the geometry of the detail or the structure
irrespective of its end element grid
The major goal during the discrete model development stage was the creation of an adequate
end element grid that contains the blocks and the elements
When building up the end element grid the following had been taken into consideration
ndash The zones that require the voltage or deformation to be defined there had been more fine
grid used compared to that related to the zoned of dislocation definition
Devices And Methods Of Experiment 43
ndash for nonlinearity the grid had been built so that nonlinear effects may be disclosed the
plasticity requires reasonable increase of integration points therefore more fine grid in the zones
with high gradient of plastic deformations
There had been algorithm developed for the procedures to calculate module to solid massif to
disturbance interface parameters in accordance with the assumed research design
Definition of distribution form that is generated by the seismic wave module in the solid
massif Setting up the parameters for wave to disturbance interface
Results processing to obtain the distribution dependences for the waves reflected due to
disturbance Acquisition of specific diagrams for single and alternate impulses
Research of beats phenomenon under the environment of forced oscillations in the massif and
inherent oscillations in the disturbance Processing of the results of reflected waves records and the
delivery of recommendations to be applied to the recording equipment
Simulation model for the interface of the vibration seismic modulelsquos executive element with
the coal solid massif represents the equations system that provides the characteristics of internal
parameters and output indicators of the executive element and the element that manages the
vibration seismic module parameters of module interfaces with the massif and tectonic
disturbances
The indicated similarities allow developing the equations for the mathematic model of the
module based on the physical model (see Figure 1) М mass representing the combination of the
reduced mass of coal solid massif that participates in the movement main executive element and
the moving liquid is situated under the impact of forces produced by the drive F(t) and R massif
reaction The drive is represented by the flexible and viscous body with the hardness coefficient CH
and Н free end of the above is moving under the velocity of Vo defined by the liquid supplied by
the source The massif is also represented by the flexible and viscous body with corresponding
hardness coefficient Сс and viscosity с During the movement the main executive element is
situated under the impact of dissipative forces of resistance Rc The movement of the mass is
executed in the interval lp that is remote from the conditions of initial reference point at the distance
Xo The background data for the research are reduced mass М coefficients that characterize the
properties of the impact object Сс and с the initial deformation force Ro extent of deformation
oRR maximum deformation velocity v maximum value of deformation lp and the reference
coordinate Xo that are linked with the ratios
1 c
o
C
Rlp 1 lpXo
М ndash reduced mass Vo ndash reduced liquid velocity F(t) ndash force from the drive
СН and Н ndash transmission hardness and viscosity coefficients R ndash impact object reaction Сс and с ndash
impact object hardness and viscosity coefficients Rc ndash reduced resistance force Хо ndash initial coordinate
lp ndash movement interval Х ndashcurrent coordinate
Fig 1 Physical model of hydraulic vibration seismic module
44 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
The single cycle of the system under research includes 2 similar in nature phases of
deformation and unloading During the deformation phase the massif deforms due to the position of
static balance towards the stimulating force in the course of unloading the massif deforms ndash from
the position of static balance in opposite direction This cycle presumes particular boundary
conditions for each period and its phases initial dislocations initial and final velocities are zero
Thereupon the movement within each phase is described by means of equations of one type while
the solutions for corresponding equations is defined by the set of additional conditions that are input
and formulated upon occurrences The accepted model determines the values of forces impacting
the massif
XXXtVCP)t(F Ho0Ho (1)
XCXXMRR cco (2)
where Ро ndash initial force from the drive X and t ndash current coordinate and time correspondingly
With regards to the above the differential equations of system movement will be displayed as
follows
а) during deformation phase
tVCXCRRPXCCXXM oHoHcoocHHc (3)
б) during unloading phase
R1RXCXXM cocH (4)
The obtained are quadric differential equations with the right part the solutions of these is
defined by the ratio of input coefficients characterizing flexible and viscous properties of the drive
and coal solid massif The equations of module managing element are set based on the
recommendations [2]
sgn20 ррppg
kdt
dyF сdisf
(5)
pFdt
dysgnRy
dt
dyФ
dt
ydM 02
2
(6)
where F ndash effective area of the cylinder μ ndashcoefficient of the flow through the working door of
the spool kf ndash proportion coefficient used during the determination of spoollsquos working door opening
section Δ ndash opening of the spoollsquos working door g ndash acceleration of gravity γ ndash specific weight of
operating liquid p0 ndash pressure of supplied operating liquid flow pdis ndash discharge pressure х ndash spool
dislocation у ndash cylinder dislocation
Working processes in coal solid massif are described by the equations recommended by
Professor Chichinin [3]
2
00
ozz 11
z
z
r
RUU
(7)
HHHin RxfMRFW
1222
2
1 (8)
r17R 2
0s2
H (9)
Devices And Methods Of Experiment 45
where Uz (z) ndash massif particles dislocation r Ө φ ndash spherical system of coordinates r0 ndash
contact radius
s
р
Uz
0 ndash initial dislocation (from statics) Fin ndash force amplitude ρ ndash massif
density f ndash frequency
The acquired system composed of 9 equations is set as a base for computer-based experiment
The analysis of the results of computer-based experiment was executed in accordance with the
principle ―from simple to complicated In accordance with this the first results were those obtained
for single impulse transferred to the massif from the seismic module
The results of computer-based experiment indicate that during the excitation of vibration
seismic signal in the strata and during further wave distribution there are 3 sections of its spread
(Figure 1) These sections are differentiated by first of all nature of amplitude changes reference
tags will be as follows I ndash the zone prior strata disturbance II ndash zone of disturbance itself III ndash
zone after disturbance
Хк ndash massif particlesrsquo dislocation t ndash time I ndash the zone prior strata disturbance II ndash zone of
disturbance itself III ndash zone after disturbance
Fig 2 Quality picture of seismic wave spread across the solid massif
The first zone is characterized by insufficient reduce of the amplitude while remaining the
frequency of the signal This is explained by the fact that when the wave is passing through the
massif it loses the energy to overcome the resistance while keeping the frequency allows to reduce
the amplitude
The second zone is attributive of chaotic changes both amplitude and form of the impulse This
phenomenon is explained by the fact that the volume of the disturbance is filled with the substance
with physical and mechanical indicators that differ from those specific for the coal The seismic
waves passing the overall volume of the disturbance are multiply reflected from its walls and this
leads to overlap of the oscillations and impulse deformation The nature of the deformation is
defined by the sizes of the disturbance chamber and type of medium
All of the analytical research presented during the work and its results are those for ideally
flexible medium that forms the massif where the waves are distributed without the dissipation of its
amplitude while the generated signal does not change its form This is different in reality Any of
real medium owns the dissipation property which sufficiently impacts the amplitude of the seismic
waves located at the significant distance from the source First of all the mathematic model
developed for computer-based experiment shall consider the frictional forces between the particles
and strata of the massif and dissipation of the energy supplied to the massif from vibration seismic
module In the result of mathematic model solutions there had been major dependences defined
such as those characterizing the amplitude of ground particles dislocation with respect to the value
46 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
of initial deformation of the breast in the point of interface with the modulelsquos executive element
(Figure 3) As displayed when there is no disturbance the quality diagrams are significantly
dependant of the breast static deformation value To get abstracted from the numbers Х0Аmax
indicator is introduced that is there to indicate the relation of the initial deformation Х0 to the
maximum amplitude of the seismic signal Аmax transferred to the massif It is obvious that Х0 le
Аmax for Х0Аmax le 1 The dependences indicate that there are 2 dislocation zones I ndash Х0Аmax gt 0 ndash
particles dislocations are observed in the direction towards signal activation zone (compression
zone) II ndash Х0Аmax lt 0 - particles dislocations in the direction opposite to signal activation zone
(recovery zone) This is fairly natural because the massif is assumed to be flexible and it tends to
recover its static condition
The analysis of dependences also indicates that in case of Х0Аmax reduction the type of the
diagram changes from practical asymptote to non-periodic oscillations The compression zone is
maximal at the large values of Х0Аmax coefficients From the physical point of view this is
conditioned by the fact that during the minor initial deformation the massif may recover its static
condition quicker
I - compression zone II ndash recovery zone
Fig 3 Reduced amplitudes of massif particlesrsquo dislocation
The diagram of signal change without the disturbance is described by Figure 4 It is shown on
the figure that the sinusoidal impulse supplied to the breast reduces its amplitude during Т time The
duration of impulse ti remains unchanged This is defined by the fact that the model captures
dissipative forces that reduce wave energy and hence its velocity The notable fact is the
permanence of impulse duration under various physical and mechanical properties of the massif
Devices And Methods Of Experiment 47
Т ndash alteration time ti ndash impulse time
Fig 4 Diagram of signal changes without disturbance
When having various types of disturbances available the diagram takes the form as shown on
Figure 4 As it is seen the main curve Хк(t) disrupts in the sections of disturbances and these
sections are filled by the corresponding curves characterized by the properties of substances located
under disturbance and geometrical sizes The wave dislocation being reflected from the boundaries
―strata-disturbance adopts corresponding form The distance to the disturbance and between them
is defined by means of known wave spread velocity values υc and fixed time The form of the
signal given the disturbance is in place changes in accordance with the diagram presented in Figure
5 The sufficient result of this research is the rapid increase of the signal amplitude within the
disturbance Being reflected from the ―massif-disturbance boundaries and due to the flexible
recovery forces of the massif and additional energy of the substance particles the disturbances
acquire additional velocity and thereupon the disturbance volume energy increases
I ndash first disturbance II ndash consequent disturbance
Fig 5 Diagram of signal change provided the disturbance is available
The results obtained during the modeling of alternate impulseslsquo processes indicate the
following Quality picture acquired for single impulse under the conditions of permanent initial
process environment is similar to the series of impulses The difference is observed in terms of
quantitative value and distribution of strata particleslsquo dislocation Figure 6 displays the results of
results processing for the experiment dedicated to the massif dislocation amplitude under the
conditions of several alternate signals of the prescribed form
48 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
1 ndash 5 imp 2 ndash 10 imp 3 ndash 15 imp 4 ndash 20 imp
Fig 6 Reduced amplitudes of massif particles dislocation under the conditions of
multiple alternations of impulses
From here it can be seen that along with the increase of impulses number the curve Х0Аmax =
f(t) goes up towards the abscissa axis and the curvature radius increases The compression zone
enlarges while the tension zone decreases and then disappears This is conditioned by the fact that
through the course of time the massif is not able to timely recover its static balance It is obvious
that under the conditions of endless increase of the impulseslsquo number the curve tends to move
towards the horizontal line This occasion is inadmissible in practice due to the below conditions
When the wave from each impulse approaches the disturbance there is particular power
injected into the disturbance that under the conditions of permanent volumes increases the pressure
and the temperature Depending on the massif condition the increment of this power may lead to the
collapse of the massif and provoke sudden outburst
References
17 Kenzhin BM Diss Doctor of Technical Science - М 1974
18 Zakharov YE Hydraulic and Electrical Hydraulic Vibrators Diss Doctor of Technical Science - М 1974
19 Chichinin AS Vibration Radiation of Seismic Waves ndash М Nedra 1984
Devices And Methods Of Experiment 49
UDC 53004
ANALYSIS OF THE PROCEDURE LCAS IN TRANSPORT NETWORKS NGSDH
DM Zakiev GP Amochaeva RA Mursalin
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The paper presents a procedure LCAS (Link Capacity Adjustment Scheme) - scheme of
regulation of channel capacity is built on virtual concatenation mechanism LCAS protocol allows
you to dynamically change the capacity of the channel without interference from staff In particular
it is interesting to create a model protocol on one of the most common programming languages
since the simulation to evaluate the effectiveness of almost any technology to run it in operation
Keywords link capacity adjustment simulation virtual concatenation dynamically change
For the last 8-10 years the situation in the communication market has sharply changed The
global information society demands new technologies that are technologies of a packet transmission
of the data and to remain in the market the operators maintaining networks with switching off
ports should provide effective drive of the package traffic Volumes of the package traffic have
increased repeatedly There is statistic data access services to the information with use info
communicational technologies (Internet) for 9 months 2010 have generated the traffic of 177 626
415 153 Mb that is 24 times more than a similar indicator in 2009
Classical SDH (Synchronous Digital Hierarchy) it was developed for traffic transmission with
constant bit speed and it is badly adapted for the package traffic drive Nevertheless high indicators
of quality and possibility of self-restoration of a network are rather attractive to use SDH as
transport for information networks However at attempt directly to pack shots of a LCN into
containers SDH engineers have faced certain difficulties but the main thing capacities of
containers were filled inefficiently Besides the networks SDH are characterized by reservation
that is the big redundancy Half of ports capacity is intended for reservation thus efficiency of
transmission falls to several tens percent mdash some experts compare such operating ratio of
throughput capacity with UAC of a steam locomotive [1]
Networks SDH are constructed and debugged the big resources are enclosed into creation and
operation and to refuse further use that means to pass to networks with switching off packages is
impossible in many ways Besides the technology is worked out for many years there are experts
and there is equipment Introduction of new technologies can change this viewpoint For example
Ethernet over SDH EoSDH can essentially expand a spectrum of services of communications
service providers as in many cases this is rather inexpensive enterprise (as SDH serves only as
transport modernization is necessary only on terminal points of a route)
For a solution of a problem of adaptation of the package traffic to ports with constant bit speed
the modern report GFP already exists and it is supported by many manufacturers allowing to
smooth pulsations of the package traffic and economically using resource of virtual containers at the
same time [2]
Typical speeds of networks of data transmission are poor coordinated with speeds SDH as
capacities of virtual containers were developed for mostly ports of the vocal traffic transmission
This question is solved by procedure of virtual concatenation allowing uniting capacities of several
containers together for maintenance of the demanded pass-band
Another problem issues that port loading can reach a maximum at certain hours and fall to a
minimum during other time It will be natural and expedient to change capacity of all port adding
50 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
or deleting the elements referring to the group of concatenated containers In data transmission
networks the traffic instead of time usage of the allocated port is usually paid
The decision of the given problem is procedure LCAS that is the scheme of resetting of
throughput capacity of the port representing a superstructure over the gear virtual конкатенации
Report LCAS allows changing the capacity of the port dynamically without staff intervention
Technology LCAS has appeared rather recently and isnt studied up to the end In particular
creation of model of the report on one of widespread programming languages is a sphere of interest
as it allows estimating efficiency of almost any technology before its start in operation
Working out the model of report LCAS in language of high level and its analysis of functioning
is the purpose of the given work
For achieving the objective it is necessary to solve following problems
1 To create the accurate description which considers difficult specificity of report LCAS
2 On the basis of the information description to create virtual model of report LCAS
3 The results received at the analysis of virtual model of report LCAS should be as much as
possible approached to the results received by means of practical modes at functioning of the report
For creation of the description of report LCAS language SDL (recommendation ITU-T Z100)
which basis is made by the concept of interaction of final automatic machines was used There are
two versions of language SDL - graphic (SDLGR) and SDL ndash program similar (SDLPR) Each
symbol SDLGR corresponds to the concept and a designation in program similar version SDL The
description of telecommunication reports in language SDL in a graphic kind represents diagrams
reflecting logic of the report sequence of operations and changes of the object condition presented
in the form of blocks [3]
Each block in the SDL-system diagram can be divided further either into blocks or a set of
processes The process describes behavior in SDL and it is the most important object in language
The behavior of each process is defined by the expanded final automatic machines which perform
operations and generates reactions (signals) in reply to external discrete influences (signals)
So process in the SDL-specification has final number of states in each of which it can accept a
number of the admissible signals sent to these process (from other processes or from the timer)
Process can be in one of the states or in transition between states If during transition the signal
intended for given process is received it is put in turn to process arrives
The operations performed during transition can include data transformation as in signal
transition to other processes etc Signals can contain the information which is defined on the basis
of the process data sending a signal in a parcel of signals and it is used by process-addressee
together with that information which this process has Besides the processes contained in the
considered system signals can also go out of the system limits to environment and arrive from
environment as well Environment is understood as everything which is out of SDL-system [4]
Sending and receiving signals their transmission by means of the information from one process
to another processing and using this information also define the way of SDL-system functioning It
is supposed that after performance of the set of operations the certain result in behavior of specified
system in particular the signaling report should be achieved As a rule the expected result will
mean that in reply to a number of the signals arriving from environment (for example the terminal
station complete set of a connecting line) the system should perform the certain operations
terminating in message transfer into environment (in the same station complete set of a connecting
line andor in other program process managing the sending of tone signals in process of
information inquiry by АND etc) [5]
For the description of report LCAS in language SDL a modified version of the report is used
some elements arent used the values of the rest ones are resulted in Figure 1
Graphic representation of sequence of states change and work mechanisms of the report gives
more evident representation about its work and it is the analysis tool as well
Devices And Methods Of Experiment 51
Report LCAS is described on diagrams SDL in detail to show the transition from one state into
another The functions performed by scheme LCAS can be broken into following sections
- A part of the report that is realized on the side of a source of group VCG
- A part of the report that is realized on the side of the receiver of group VCG
It is necessary to mean that the information stream from a source to the receiver is intended on
each separate element of group VCG ie SQ CTRL CRC and MFI The stream of the information
from the receiver to a source occurs by definition that is general for all elements of group VCG
Using these streams it is possible to make the further division
- A part performing functions on the source side transferring the information of each separate
element to the receiver side ie SQ CTRL CRC MFI Information interchange SQ between group
VCG elements is made Information SQ is also transferred to a reception side to steer the
distribution MST of a corresponding element
- A part performing functions on the receiver side both transferring the information of each
separate element from the side of a source are directing SQ and the status of elements of the
following part
- A part which is performing functions on the receiver side receiving the information
concerning all elements of group VCG ie the status of elements of group VCG as a whole and
conferring the revealed change in numbering of sequence of group VCG
- A part which is performing functions on the source side receiving the information
concerning all elements of group VCG ie VCG MST and RS-Ack and distributing MST of each
part of the element of group VCG
In Figure 1 these parts are shown and the information stream between these parts is presented
Figure 2 shows events signals that have been exchanged by separate parts of report LCAS
Fig 1 Highlighting the sections of report LCAS
Figures 3 and 4 describe behavior of the source and the receiver accordingly in language SDL of diagrams
52 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Fig 2 the stream of events of report LCAS
Fig 3 Diagram of the source side states
Devices And Methods Of Experiment 53
Fig 4 Diagram of the source side states
Owing to the evident description of report LCAS in language SDL it is simple to make the
information model of report LCAS which is based on the description of elements VCG of the
source and the receiver in a programming language of high level as final automatic machines The
language C ++ was chosen as a language of high level as the most suitable one in respect of
simplicity of the class admission describing final automatic machines of the source and the receiver
RESULTS OF MODELLING WORK OF REPORT LCAS
Lets consider some scenarios of work of report LCAS using of the received model In each
case the function contents mainlsquo will change The target data are files of journals it is possible to
estimate correctness of work of the program referring to them
1 Addition of two VC to VCG by turn and simultaneously
The key moment while addition the elements is the correct establishment (distribution) of
indicators of sequence on the source side We will check up the correctness of work of model when
adding several containers simultaneously In this case two containers in the first example by turns
in the second one simultaneously are added Initially all elements are in position IDLE in group
there are no active containers
Results of work of the program are resulted in table 1
The control system submits signals of addition to elements by turns sequence indicators
receive numbers 0 and 1 accordingly
Lets consider further simultaneous addition identifiers can not coincide with the previous case
but not with each other
Simultaneous addition
54 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Table 1 Journal of the source and the receiver of the container 1
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=1| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt (OK)
Start sending payload
(NORMEOS)
Table 2 Journal of the source and the receiver of the container 2
Источник (Source) Приѐмник (Sink)
(IDLE) (IDLE)
gtМ ADD| gtM ADD|
|SQ=0| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=1| (OK)
|n=2|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
Lets notice that log entries correspond to the report and sequence indicators are established
truly In this case as well as at addition of elements by turns the model works truly
2 Removal of an element
In case of element removal as well as while addition change of the indicator of number of
sequence demands attention When removing the last element of group field CTRL of the
penultimate element (having the highest number of sequence) changes Numbering of the sequence
and steering fields of other elements in group are not changed If not last element is removed
numbers of sequences more than the removed one should be counted
Lets create the scenario in which three elements at first are added then one of them we will
remove At first we will consider the removal of the second element then removal of the last the
third one
Removal of not last element of group
For creation of the specified scenario in the basic program the steering command about addition
of three elements is given and after processing of signals by function mainlsquo the second container
receives a command for removal and function mainlsquo is caused again Journals of work for
Devices And Methods Of Experiment 55
elements of the second and third containers are resulted as removal of the second container doesnt
affect the work of the first one
Having received a removal command the source notifies about sequence change it ceases to
send loading and having put SQ = 255 passes to a disabled state
Table 3 Journal of the source and the receiver of the container 3
Источник (Source) Приѐмник (Sink)
(IDLE) gtM_ADD| (IDLE) gtM_ADD|
|SQ=O| (FAIL)
|F ADDgt gtF_ADD|
(ADD) Connectivity check
gtR OK| |R OKgt
|SQ=2| (OK)
|n=3|
|F EOSgt gtF_EOS|
|S RSQgt Reading payload
|C_NRMgt |S RSQgt
Start sending payload (OK)
(NORMEOS)
gtC RSQ|
|SQ=1|
C RSQgt
(NORMEOS)
Apparently from table 3 the source of the second element informs the receiver about the
change of number of sequence and changes it from SQ=2 to SQ=1 and also informs that now it is
the last one in the sequence The model works right
In this case elements having received a command of removal of the container following report
LCAS put the container out of work establishing SQ=255 pass in a disabled state
In work the information model of report LCAS is developed The created model adequately
reflects principles of work of the report While steering signals affect the system of elements the
model processed them correctly the elements were transferred into the necessary states and thus
they sent signal messages to each other The journals of work of elements received during modeling
help to find out correctness of processing of messages of a model for debugging of a model or on
the contrary they can help to find feeble sides in report LCAS
As the report LCAS is for today young enough and it is not studied up to the end the results
received in given work can be of interest both as a methodical material and for use in research
work
References
1 NGSDH success is inevitable Part 1 New principles of measurement in modern systems of data
transmission IG Baklanov Connect The world of communications - 2004 - 11 -P 164-167
2 SDH Networks new generation and use them for backhaul Ethernet Electronics NTB - 2005 - gt
34
3 Recommendation ITU-T G7042 Y 1305 (032006) Capacity Adjustment Scheme lines (LCAS) for virtual
concatenated signals
4 Statistics of the industry information exchange on the communication networks Web site of the Ministry
of Information Technologies and Communications - Httpminsvyazruindustry 11933010
5 ITU-T Recommendation G7041Y1303 (082005) The general procedure for framing
56 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
UDC 53004
RESEARCH OF INFLUENCE OF SPEECH CODECS ON TRANSMISSION QUALITY OF
THE DIGITAL SIGNAL
ZhK Ishchanova GP Amochaeva AK Tussupbekova
Karaganda state University named after EA Buketov Universitetskaia St 28 Karaganda 100026 Kazakhstan Karaganda_07mailru
The Kazakhstan telephone system of the general using contains both analog and digital
segments For a long time analog segments served for an information exchange between
subscribers however introduction of digital segments has led qualitative information transfer for
long distances because digital technologies possess a number of advantages
Keywords analog segments telephone system signal constellations characteristics of errors telephone ports
Digital segments are less subjected to distortion and interference when comparing with analog
ones As binary digital ports give a significant signal only at work in one of two states that is
switched onlsquo and switched offlsquo disturbance should be great enough to tranfer a working point of
the port from one state into another one Presence of only two states facilitates restoration of a
signal and hence prevents accumulation in the course of noise transmission or other disturbances
While using digital technologies very low frequency of occurrence of errors plus application the
procedures of revealing and correction of errors make possible high frequent accuracy of a signal
There are also other important advantages of digital communication Digital links are more reliable
and can be produced at lower prices than analog ones Besides the digital software admits more
flexible realization than analog ones [1]
Despite achievements in the field of high-speed digital transmission systems modems for
commutated telephone ports keep their appeal Because for introduction of high-speed technologies
such as xDSL Ethernet data transmission in networks of mobile connection of the 2nd and 3rd
generations modernization of a communication network and installation of the expensive
equipment are required Therefore transmission of digital data by analog ports by means of the
modem that is technology dial-up is used in telephony It is explained by a wide circulation and
availability of such ports where the primary appointment was speech transmission If a subscriber
can use only analog port then only the modem can solve its problems on data transmission Modem
access remains especially claimed at departmental communication networks (for example at power
engineering networks oil industry workers) and also in the remote and sparsely populated areas of
Kazakhstan [2]
The dial-up technology is less modernized and noise immuned in comparison with xDSL
Ethernet an IP-telephony data transmission in networks of mobile connection of the 2nd and 3rd
generations however it is simple in the realization and doesnt demand the great expenses
Therefore this technology is the most comprehensible in telephone systems as at present the
cardinal telephony change is impossible The dial-up technology provides gradual transition to use
of digital segments joining them to analog segments
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation (PAM-technology) and two-dimensional symbols quarter amplitude
modulation (KAM- technology) For data transmission by telephone ports it is recommended to use
only two-dimensional symbols of KAM- technology because while coding these signals are set by
two parameters that is accepted to consider more exact reproduction of the information Therefore
in given article the method of quarter amplitude modulation is considered as this mode of
modulation is recommended by ISES for use in telephone ports [3]
Devices And Methods Of Experiment 57
On joints of digital and analog segments of a network standard codecs ICМ are used Standard
codecs possess a number of advantages they are less sensitive to digital errors bypassing and bring
an insignificant delay of a signal Use of these codecs allows to have a considerable quantity of
consecutive transitions on a network without essential drop of quality [2]
Analog data is represented by digital signals and transferred by telephone ports by means of
codecs (coderdecoder) which approximate signals by means of bit streams While analog-digital
transformation of a linear signal of the codec the former is exposed to specific distortions that lead
to increase of error probability Digital signals are subjected to influence of noise of coders which
are impossible to simulate and count manually as noise is a random variable
A lof of works are devoted to problems of digital signals transmission by analog ports
However a number of problems of speech codecs concerning influence namely logarithmic and
nonlinear ones on quality of QАМ-signals transmission in the scientific literature are regarded
insufficiently Therefore the theme of the research of speech codecs influence on digital signals is
actual
In the given article influence of speech codecs on quality of digital information transmission by
telephone ports will be investigated Namely influence of the analog-digital converter on QАМ-
signals transmission as these signals is exposed to influence of specific distortions which cant be
simulated by additive Gaussian noise that is connected with nonlinearity of the used quantizator In
this connection points of constellations of QАМ-signals distant from the center are subjected to
stronger influence of distortions than near ones Accordingly the object of the article is speech
codecs
The research objective is investigation of speech codecs influence on qualities of digital signals
transmission of QАМ-technology the estimation of influence degree is made by computer
modeling
For achievement of the specified purpose following problems are solved
1 The comparative analysis of existing methods of analog-digital transformation of speech
signals
2 The analysis of properties of signals of quantizator amplitude modulation
3 The theoretical analysis of influence of codecs ICМ on quality of QАМ ndash signals
transmission
4 Creation of imitating model of influence of analog-digital transformation on the QАМ-
signal
5 Investigation the received model
While carrying out the investigation methods of the theory of digital processing of signals
theories of chains and signals theories of electric connection the theory of the information and
casual processes methods of mathematical statistics and engine modeling have been used
Scientific novelty of the given work issues that by means of computer modulation the imitating
model of quantizator IKM-codec influence on KAM-signals by means of which it is possible to
estimate influence as own noise of system ndash additive noise and other noises Moreover by means of
the created program it is possible to state an estimation of the minimum achievable probability of an
error by drive of digital KAM-signals by the telephone port equipped with codecs ICМ
There is a set of methods of coding for transformation of an analog signal into the digital form -
time frequency parametrical Methods of frequency coding of the information issue in modulation
by information signal on so-called carrying frequencieslsquo Methods of time coding issue in the exact
description and reproduction of the form of fluctuations in time ie we code directly the signal
form They include ICМ with a uniform and non-uniform scale of quantization DICМ delta-
modulation АДКМ coding with splitting on subgamuts Parametrical coding is based on use of
voice coders which use the analysis for transformation and representation in a short form and
synthesis for restoration of a source speech signal on the basis of its short representation
58 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Referring to stated above it is possible to make a conclusion that it is considered to be the best
methods of time coding because they are noise defended most of all From all methods of coding in
time area the greatest distribution in digital telephony methods ICМ and АDICM were accepted
since their realization is a simple and at the same time useful signal that is easier to identify while
hindrances distortions and noise of converters
ICМ issues in representation of a continuous analog signal in the form of sequence equidistant
from each other impulses where their amplitude is presented by a binary code (quantization on
level) and coding as well Similar transformation allows raising essentially reliability of signal
transmission and storage АDICM is a modernized version of DICМ which issues in the following
prediction the current value of reference point on the basis of previous M reference point Its
modernization issues that here quantizator and the predictor adapt to the changing environment of
an entrance signal
Data transmission by analog ports can be carried out using both one-dimensional symbols of
pulse-amplitude modulation and two-dimensional symbols quarter amplitude modulation ISES
recommends using only two-dimensional symbols of QАМ-technology for data transmission by TF
ports Two-dimensional signals as information transfer sources by the telephone port are more
reliable economic and profitable because two information parameters are already a pledge of noise
defended and better transmission Therefore in the thesis two-dimensional signals namely QАМ-
signals are considered QАМ-signals turn out by simultaneous change of inphase (I) and quarter (Q)
amplitude a component of the carrying harmonious fluctuation shifted on a phase from each other
on π2 The resultant signal Z is formed as a result of summation of these fluctuations
QАМ-modulation is formed by simultaneous coding of amplitude and a phase of carrying
fluctuation For the given modulation it is characteristic that while modulation of inphase and
quarter components of carrying fluctuation the same value of a change pace of amplitude is used
Therefore the terminations of vectors of the modulated fluctuation form a rectangular grid on a
phase plane valid - Re Z and imaginary - Im Z components of a vector of the modulated signal
The number of knots of this grid is defined by type of used algorithm QАМ The scheme of knots
arrangement on a phase plane modulated QАМ fluctuations is accepted to name constellationlsquo
In work the analysis of recommendations ISES for the modems working on telephone ports
using the given kind of modulation is carried out [4]
Since the introduction of digital segments equipment ICМ (reliable for transformation of the
analog information into digital information) has great influences on quality of QАМ-signals
transmission ICМ the codec in a telephone system possesses the certain nonlinearity providing
increase of quantizator efficiency for speech signals This nonlinearity reduces productivity of
modems such decline of productivity in directly proportional to speed increase of data
transmission In the second chapter of the thesis the attention to influence of logarithmic and
nonlinear quantizator on quality of QАМ-signals transmission is focused
While carrying out the analysis of influence of the speech codec on the QАМ-signal the
following conclusions have been made
1 The codec includes a logarithmic or nonlinear compander hence an error of each referring
point is regular distributed interval random variable that is proportional to the value of the referring
point
2 The transmitted signal is generated by two kinds of noise that are multiplicative and additive
ones where first makes more impact on value of error probability
3 With growth of amplitude of referring point the noise value grows as well
4 Noise has the ellipse form however an ellipse axis doesnt coincide with a radial axis of a
point of constellation
5 The size of constellation makes less impact on quantization noise than its form
To estimate influence of additive and multiplicative noise on points of constellation of QАМ-
signals the imitating model of influence of the ICМ-codec on the digital signal transferred by
Devices And Methods Of Experiment 59
telephone ports has been created Because the theoretical estimation of influence of noise takes a lot
of time and doesnt show an evident picture of signal constellations of QАМ-signals The program
consists of two modules The first module is used for construction of points of constellation of the
QАМ-signal and composing schedules of noise distribution around the constellation points This
module creates the evident picture of signal constellation subjected to influence of multiplicative
and additive noise The second module is used for calculation of noise immunity of a signal and
construction of the schedule of dependence of error factor on noise immunities by additive and
multiplicative noises
The program is realized in a programming language C++ Information input and output in the
program is realized through the operating system console
To write the program of imitating model algorithms of their work have been initially created
By the block diagram the code of work of the module which is programmed in the program farlsquo in
language C++ has been created
In Figure 1 the window of already created program of the first module is resulted where the
initial data for calculation of error quantity error factor and value AQD of noise are requested A
number of iterations the maximum pressure of a constellation point on an one-dimensional axis and
noise immunity on additive and multiplicative noises are accordingly related
Fig 1 Window of input-output calculations of the first module
This model has a number of advantages because it gives out results for all types
of QАМ-signals It is enough to enter the variables of investigated type and
depending on them corresponding results will be resulted
The first module deduces the quantity of errors error factor and value of noise
AQD This module proves that the transmitted signal is generated by two kinds of
noise - multiplicate and additive and with growth of amplitude of readout the noise
size grows also
Further the signal constellation depending on number QАМ is constructed The
program shows an evident picture of distribution of noise by vectorgram where ratios
60 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
between multiplicative and additive noise and error probability are considered By
means of the received data it is evident that noise has the ellipse form and the ellipse
axis doesnt coincide with a radial axis of constellation point
For an example in article results of calculations of the program for three
constellations are resulted QАМ-16 QАМ-64 QАМ-268 The kind of signal
constellation depends on a ratio between the signal and the noise
For QАМ -16 signal constellations on an input of the solving device with a ratio
between a signal and noise equal 175 dB and 20 dB for error probability 10-3
look as
follows (fig 2)
Fig 2 Signal constellations QАМ-16 having 517ЗиА dB 20ЗиА dB
Having analysed the received images it is possible to draw a conclusion that with ratio growth
between a signal and noise of constellation points lose its ellipse form
By results for QАМ-64 and QАМ-268 signal constellations on an input of the solving device at
ratios between the signal and the noise equal 23 dB and 30 dB accordingly for error probability 10-3
look like (fig 3)
Fig 3 Signal constellations QАМ-64 at 23ЗиА dB and QАМ-268 at 30ЗиА dB
Their difference issues in a number of constellation points
Devices And Methods Of Experiment 61
The second module of the program is intended for calculation of noise immunity of a signal and
construction of the schedule of error factor dependence on noise immunities on additive and
multiplicative noise
In Figure 4 calculating windows of the second module is presented Such initial data of a signal
are requested as QАМ type the maximum pressure of a point of constellation on an one-
dimensional axis and area on which it is necessary to investigate noise immunity that is the
maximum and minimum values and it is necessary to choose a type of investigation concerning
additive or multiplicative noise
Fig 4 The window of input-output of the second module for QАМ-16
Characteristics of errors (fig 5) are received by means of the program curveslsquo
Fig 5 Characteristics of errors
62 Eurasian Physical Technical Journal 2011 Vol8 No1(15)
Curves 1 and 2 correspond to constellation QАМ-16 the curve 1 describes dependence of error
factor on noise immunity on additive noise a curve 2 - on noise immunity on multiplicative noise
Curves 3 and 4 correspond to constellation QАМ-64 and also describe dependence of error
factor on noise immunity on additive and multiplicative noise
Curves 5 and 6 correspond to constellation QАМ-256
As while transmission QАМ signal by the telephone port to system there are both additive and
multiplicative noise components the real curve will lie between the curves constructed for cases of
pure additive and pure multiplicative noise
While carrying out the investigation of speech codecs influence on quality of digital signals
transmission by means of computer modeling the following conclusions have been formulated
1 The program which states the estimation of influence degree of speech codecs on quality of
QАМ-signals transmission by computer modulation is developed
2 From the received results of imitating model of the first module it is evident that with ratio
increase between the signal and noise constellation points lose their elliptic shape that is confirmed
by theoretical calculations
3 The second module of the program shows that with increase of the number of the QАМ-
signal its noise immunity increases as well multiplicative noise makes more essential impact on
value of error probability and accordingly demands more noise immunity
4 The regarded program is possible to recommend for experts in the field of working out of
telecommunication equipment and in educational process
Apparently from the resulted schedules the multiplicative noise makes more essential impact
on value of error probability and accordingly it demands more noise immunity (2-3 dB more) for
maintenance the demanded error probability
The results received in article can be used in the further theoretical researches when designing
the transmission systems using telephone ports and in the course of training while consideration the
modem reports and processes of digital information transmission by telephone ports
References
1 Bellami Dj Digital telephony ndash M Eko-Trends 2004- 640 p
2 Kuricyn SA Base of construction telecommunication system of transmission ndash SPb Information centre of
voice 2004
3 Rabiner LRShafer RV Digital processing of speech signal ndash M Radio and connection 1981 ndash 463p
4 Kruhmalev VV Gordienko VN Mochenov AD Digital system of transmission Hot line ndash Telecom2007
ndash 350p
63
SUMMARIES TYCІНІКТЕР АННОТАЦИИ
ВИ Олешко СС Вильчинская СГ Горина Время-разрешенная люминесцентная спектрометрия
кристаллов селенида цинка Измерены спектральные и кинетические характеристики импульсной
катодолюминесценции нелегированных монокристаллов ZnSe полученных путем сублимацией из паровой
фазы (метод Давыдова-Маркова) и выращиванием из расплава (метод Бриджмена) Установлено что в спектрах
излучательной рекомбинации селенида цинка наблюдается три группы полос ndash экситонные краевое излучение
и полосы обусловленные рекомбинацией носителей на глубоких центрах Изучены спектрально-кинетические
характеристики краевого излучения в кристаллах ZnSe различной предыстории Установлено что количество
серий краевого излучения соотношение их интенсивностей и спектральное положение определяются
предысторией кристаллов Показано что при повышении температуры в интервале 15-80 К общая
интенсивность краевого излучения уменьшается более чем на порядок Полученные результаты показывают
что свойства краевого излучения хорошо описываются с помощью модели донорно-акцепторных пар
ВИ Олешко СС Вильчинская СГ Горина Мырыш селенид кристалының уақыт бойынша ажыратылған
люминесценттік спектрометриясы
Ертінден өсірілген (Бриджмен әдісі) және бу фазасынан сублимация арқылы алынған (Давыдов-Марковтың
әдісі) легирленбеген ZnSe монокристалдардың импульстік катодо-люминесценциясының спектрлік және
кинетикалық сипаттамалары өлшенді Мырыш селенидінің сәулелену рекомбинация спектрлерінде үш топ
жолақтар экситондық шеткі сәулелену және терең орналасқан центрлеріндегі тасымалдаушылардың
рекомбинациясымен шартталған жолақтар байқалатыны дәлелденді Әр түрлі табиғатына байланысты ZnSe
кристалының шеткі сәулелерінің спектрлік-кинетикалық қасиеттері қарастырылды Шеткі сәулелерінің
топтамаларының саны олардың қарқындылықтардың қатынасы және спектрдегі орналасуы кристалдардың
табиғатымен анықталатыны көрсетілген (15-80)К аймағында температура жоғарылатуында шеткі сәулеленудің
қарқындылығы бір реттілікке азаятыны көрсетілген Алынған нәтижелер шеткі сәулелену қасиеттерінің донор-
акцепторлық қос жұпты үлгi арқылы жақсы сипатталғанын көрсетедi
ВМЮров Поверхностное натяжение чистых металлов В работе рассмотрены вопросы экспериментального
определения поверхностного натяжения массивных образцов и наночастиц чистых металлов Предложена
модель позволяющая с хорошей точностью определять величину поверхностного натяжения ее зависимость от
температуры и от размера частиц Результаты расчетов сравниваются с известными моделями и методом
laquoнулевой ползучестиraquo
Работа выполнена в рамках Программы фундаментальных исследований МОН РК Грант 1034 ФИ
ВМ Юров Таза металдардың беттік тартылуы Жумыста қарастырылған сұрақтар массалық үлгілердің
беттік тартылуының экспериментальді анықтамасы және таза металдың нанобөлшектері Беттік тартылу-дың
ұзындығын жақсы дәлдікпен анықтауға модель ұсынылғанол температура және бөлшек пішініне қатысты
Есептеу нәтижесі белгілі модельдермен және laquoнөлдік өтуменraquo салыстырылады
Жұмыс МОН РК-ның Фундаментал зерттеулер программа бойынша жасалды 1034 ФИ Гранты
КС Бактыбеков МК Мырзахмет М Никл В Джери К Бекмырза О люминесцентных свойствах
монокристаллов сложных сульфатов активированных таллием Исследованы центры люминесценции в
активированных таллием кристаллах сульфата аммония и в смешанных кристаллах Кристаллы сульфата
аммония и смешанных сульфатов лития и калия чистые и в присутствии примеси таллия выращены из водного
раствора методом медленного испарения при комнатной температуре Cпектры рентгенолюминесценции всех
измеренных образцов показаны в сравнении со стандартным сцинтиллятором BGO Показано что центры
люминесценции являются однозарядными ионами таллия Две различные позиции замещения слабо
сказываются на люминесцентных характеристиках этих кристаллов
ҚС Бақтыбеков МК Мырзахмет М Никл В Джери К Бекмырза Таллиймен активтендірілген күрделі
сульфаттар монокристаллдарының люминесценттік қасиеттері жайлы Аммоний сульфаты кристалдары
мен аралас кристалдарда таллимен активтендірілген люминесценция центрлері зерттелген Амоний сульфаты
мен литий және калий аралас сульфаттарының таза және талий иондары ендірілген кристаллдары бөлме
температурасында су ерітіндісінен баяу буландыру әдісімен алынған Барлық зерттелген үлгілердің
рентгенолюминесценция спектрлері BGO стандартты сцинтилляторымен салыстырмалы түрде көрсетілген
Люминесценция центрлері таллидің бір зарядты иондары болып табылатындығы көрсетілген Орынбасудың екі
әртүрлі позициялары кристалдардың люминесценттік сипаттамаларына әлсіз әсер етеді
64
ИВ Поярков Гравитационная конвекция в газовой системе Ar ndash N2 Экспериментально исследована
граница перехода laquoдиффузия ndash гравитационная конвекцияraquo при различных давлениях и постоянном значении
градиента температуры в бинарной системе Аргон-Азот Изучено взаимное влияние градиента температуры и
градиента концентрации в градиент плотности В системе с неустойчивой стратификацией плотности
наблюдаются два режима смешения диффузия и конвективный массоперенос Показано что срыв
диффузионного процесса для изотермического и неизотермического смешения наступает при одном и том же
давлении Интенсивность конвективного массопереноса уменьшается при наличие градиента температуры
ИВ Поярков Ar ndash N2 газ жүйесіндегі гравитациялық конвекция Азот-Аргон бинарлық жүйесіндегі
температура градиентінің тұрақты мәні мен ―диффузия ndash гравитациялық конвекция өту шегі әртүрлі қысымда
эксперимент түрінде зерттелді Тығыздық градиентіне температура мен концентрация градиенттерінің әсері
зерттелді Тығыздығы орнықсыз жүйелерде екі түрлі араласу байқалады диффузия және конвективті
массатасымалдау Изотерімді және изотерімді емес араласуларда диффузиялық процесстің конвективті
процеске ауысуы бірдей қысымда өтетіндігі көрсетілген Температура градиенті кезінде конвективтік
массатасымалдаудың қарқындылығы төмендейді
ЗЖ Жанабаев ТЮ Гревцева Нелинейные фракталы и экситонные образования в
наноструктурированных полупроводниках Предлагается фрактальная модель энергетического спектра
экситонов в аморфных пористых полупроводниках из-за хаотичности структуры которых известная аналогия
экситона с водородоподобным атомом становится неполной Получены уравнения для энергии экситона
биэкситона и триона в зависимости от энергии возбуждающего фотона Приведено сопоставление теории с
экспериментами последних лет Теория указывает наличие наиболее универсальных закономерностей
присущих динамическим системам
ЗЖ Жаңабаев Т Ю Гревцева Бейсызық фракталдар және наноқұрылымды шалаөткізгіштердегі
экситондық құрылымдар Аморфты босқыл шалаөткізгіштердегі экситондар спектрінің фракталдық моделі
ұсынылған Бұл көрсетілген орталарда экситонның сутегі атомына ұқсастық моделі орындалмайды
Экситонның биэкситонның трионның энергиясының қоздырушы фотон энергиясына байланысын анықтайтын
теңдеулер алынған Теория соңғы жылдардағы экспериментпен салыстырылған Динамикалық жүйелерге сай
мейлінше әмбебап заңдылықтар бар екендігі теория жүзінде көрсетілген
ЛЛМиньков МДФаргхали ИГДик Гидродинамика гидроциклона со встроенным инжектором В статье
рассматривается численное моделирование трехмерного поля течения в гидроциклоне с инжектором
содержащим пять тангенциально направленных сопла на основе k--RNG модели турбулентности Результаты
моделирования сравнивались с результатами экспериментальных исследований Показано что направление
движения инжектированной жидкости в гидроциклоне зависит от расхода воды через инжектор Эксперименты
и расчеты показывают что зависимость сплит-параметра от расхода инжектируемой жидкости имеет
немонотонный характер связанный с соотношением мощностей потока жидкости через основной вход и
инжектор
ЛЛМиньков МДФаргхали ИГДик Ішіне инжектор орналастырылған гидроциклонның
гидродинамикасы Мақалада тангенс бойынша бағытталған бес түтiгі бар және ішіне инжектор
орналастырылған гидроциклондағы ағының үш өлшемді өрісін турбуленттік k--RNG үлгісінің негізінде
сандық моделдеуі қарастырылған Модельдеу есептеулері тәжирибелік зерттеу нәтижелерімен
салыстырылады Гидроциклонға инжектірілген сұйықтың қозғалыс бағытының сұйықтың шығынына
тәуелділігі көрсетілген Тәжирибелік нәтижелер мен есептеулер сплит-параметрдің инжектірілген сұйықтың
шығынына тәуелділігі бірқалыпты емес екендігі көрсетеді оның түрі негізгі саңылау арқылы және
инжекторланған сұйық ағындағы қуаттарының қатынасымен анықталады
ЮМ Смирнов БМ Кенжин МА Журунова Результаты имитационного моделирования системы
laquoвибрационно-сейсмический модуль-массив-нарушениеraquo Статья посвящена исследованию взаимодействия
генератора механических колебаний ndash вибрационно-сейсмического модуля ndash с углепородным массивом В
результате установлены качественные и количественные зависимости распространения упругих сейсмических
колебаний в углепородном массиве
ЮМ Смирнов БМ Кенжин МА Журунова Ұқсастырын үлгілеу жүйесінің нәтижелері laquoдірілдеткіш-
сейсмикалық модульndashсілемndashбұзылымraquo Мақала механикалық тербелістер генераторының ndash дірілді ndash
сейсмикалық модульдің көмірлі жыныс алабымен өзара әсерлесуін зерттеуге арналған Нәтижесінде көмірлі
жыныс алабына тараған серпімді сейсмикалық тербелістердің сапалы және мөлшерлік тәуелділігі белгіленді
65
ГП Амочаева ДМ Закиев РА Мурзалин Анализ процедуры LCAS в транспортных сетях NGSDH В
работе представлена процедура - LCAS (Схема регулировки пропускной способности канала) представляющая
собой надстройку над механизмом виртуальной конкатенации Протокол LCAS позволяет динамически
изменять ѐмкость канала без вмешательства обслуживающего персонала В частности представляет интерес
создание модели протокола на одном из распространѐнных языков программирования поскольку
моделирование позволяет оценить эффективность почти любой технологии до запуска еѐ в эксплуатацию
ГП Амочаева ДМ Закиев РА Мурзалин NGSDH транспорттық желісіндегі LCAS процедурасының
талдауы Берілген жұмыста LCAS (Арнаның өткізу қабілетін реттеу сұлбасы) процедурасы яғни виртуальды
конкатенция механизіміне реттеме жүргізетін арнаның өткізу қабілеттілігін реттеу сұлбасы келтірілген LCAS
протоколы арнаның сыйымдылығын қызмет көрсетушілердің араласуынсыз динамикалық түрде өзгертуіне
мүмкіндік береді Кез келген технологияның эффективтілігін басынан аяғына дейін тек осы әдіспен бағалауға
болуына байланысты протоколдың моделін ең кең тараған программалау тілінде жасау да үлкен қызығушылық
тудырып отыр
ЖК Ищанова ГП Амочаева АКТусупбекова Исследование влияния речевых кодеков на качество
передачи цифрового сигнала В данной статье рассматривается влияние речевых кодеков на Квадратурно-
Амплитудные Модулированные (КАМ) сигналы Оценка степени влияния производиться путем создания
имитационной модели Данная модель реализуется с помощью программы Borland C++Builder 6 Полученные
результаты показывают что вероятность ошибки зависит от КАМ сигналов Это программа может быть
использована в разработке новых телекоммуникационных устройств а так же в учебном процессе
ЖК Ищанова ГПАмочаева АК Тусупбекова Сандық дабылдардың таралу сапасыны сөздік кодектердің
әсерін зерттеу Мақалада дыбыстық кодектерді Квадраттық Амплитудалық Модульделген (КАМ)
сигналдарына әсер етуі қарастырылады Бағалау жасанды модельдің көмегімен жүргізілді Модель Borland
C++Builder 6 бағдарламасының негізінде құрастырылды Алынған нәтижелерді сараптай отырып бөгетке
қарсы тұру қабілеттілік Алынған нәтижелер қателіктер ықтималдылығының КАМ тәуелді екенін көрсетеді Бұл
бағдарламаны жаңа телекоммуникациялық құрылғылар дайындауда сондай- ақ оқу үдерісінде пайдалануға
болады
Guidelines for authors
Manuscripts and short notes are accepted for exclusive publication in the ―eurasian physical technical journal The
editors reserve the right to accept or reject manuscripts Authors are not reimbursed for articles
The manuscripts and short notes must contain original results of investigation in the following areas
Non-linear physics
Heat physics hydrodynamics energetic
Condensed matter physics
Technology of the creation new material
Ecological aspects of new technologies
Modeling of the nonlinear physical processes
Theoretical physics physics of space
Devices and methods of experiment Lying within the above areas scientific-technical information scientific life chronicles reviews may be published
by preliminary agreement with the editor board The text of a paper must not exceed 10 pages including tables figures
(no more than 6) and references A short note must not exceed 5 pages including no more than 2 figures A review
paper must not be more than 20 pages (including no more than 10 figures)
All publishing manuscripts and short notes must have recommendation from a member of the editor board and
from the organization or company where the work was performed
Author(s) shall submit two copies of the paper Both copies shall be on good quality paper of international size a4
The text must be printed in 12 point letters lines double spaced There shall be a margin of 30 mm at the left-hand edge
of 15 mm at the fore edge of 30 mm at the head of the page and of 30 mm at the tail All pages must be numbered
The paper short note or review paper shall include an abstract of the contents not exceeding two hundred words in
length The abstract must not coincide with the introduction or conclusive part of the work and must not contain
references abbreviations and other unknown words All texts must be printed in microsoft word It is preferable to use
the times fonts
Acknowledgments may be shown at the end of the abstract All references must be numbered in the text (for
example [1] [2-4]) and listed in numerical order Tables must be inserted into the text Figures shall be submitted on
the separate sheets and not included into the text
The following files must be submitted via e-mail
- Article text (doc)
- Figures (fig1jpg fig2pcx)
- Figure captions (txt doc)
- The text file containing Authorslsquo names organizations postal code postal address telephone fax E-mail
scientific area of the paper
IT IS POSSIBLE TO USE RAR OR ZIP COMPRESSORS AND TO TRANSMIT THE FILES AS AN
ATTACHMENT
Title page (specimen)
TITLE
JH Smith HJ Cooper
Karaganda State University Universitetskaia Str 28 Karaganda 100026 Kazakhstan
emailfor_correspondencekz
Abstract
Article text
Context of papers are presented in author versions
Editorial board is not responsible for the content of the publications
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