Microsoft PowerPoint - 20130502b_BO_Sapporo.ppt []May 2, 2013
photocatalytic reaction of naphthalene by titania
no reports on elemental analysis: gas chromatographic data only required matching of elemental analysis within 0.3%
problem in photocatalytic organic synthesis
OH OH CHO
CHO
both of them are of C10H8O2 = 160.05both of them are of C10H8O2 = 160.05
in original report in revised report
2013/05/02—Advanced Course in Molecular Environmental Science 3
necessary and sufficient conditions
conditions
if this is the object compound molecular weight should be ... elemental analysis should be ... NMR spectrum should be ... infrared absorption spectrum should be ...
(ONLY) probability is HIGH = no proof
A
B
Mount Everest
ridge three climbing routes
requisites for a researcher
with basic facilities
• fundamental knowledge and skills • communication skills (not only in English) • just doing it, without looking for the reason for not doing • double check: humility for one's work
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How do you say?
How do you say?
"microwave oven" or "microwave"
"nuke" or "micro"
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penetration of home electric appliances > 90% at1997/ca. 99% at 2009 for microwave oven
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mechanism of microwave cooking
Q Why foods are heated in a microwave oven? Interpret scientifically.
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what is electromagnetic wave
Light is electromagnetic wave. Which are electromagnetic waves? alpha beam, beta beam, gamma beam, X ray, ultraviolet light, visible light, infrared light, microwave, radio wave, electron beam




Q: speed of light
• The shorter the wavelength, the higher the energy.
• The speed of light is constant in vacuum, not depending on its wavelength:
ca. 3 x 108 m s-1
• number of vibration per unit time = frequency (Hz)
• wavelength x frequency = (speed of light)
• (speed of light)/wavelength = frequency
microwave
2.45 GHz2.45 GHz
rotational and translational energies
molecular rotation Molecules can be rotated if they have dipole moment than changes by rotational motion. Relating to heating in a microwave oven quantized
translational energy motion of molecules themselves not quantized = continuous
2013/05/02—Advanced Course in Molecular Environmental Science 14
fate of excited states
Unstable excited state(s) tends to release energy by (1) deactivation: transition back to the ground state (2) redox reaction(s)
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microwave heating = rotational excitation
• microwave from magnetron (oscillator): 2.45 GHz (12-cm wavelength) • Water molecules are rotationally excited. Note that water molecules are
rotating even without microwave irradiation and that water molecules in ice are not fixed, i.e., not rotating and thereby no absorption of microwave.
• relaxation: releasing heat as translational energy
energy conversion electromagnetic wave — rotational energy — translational energy (heat)
keyword rotational excitation and relaxation
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mechanism of microwave cooking
Q Why foods are heated in a microwave oven? Interpret scientifically.

?
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(1) (2) (3) (4) (5)
http://www.chemistryquestion.com/index.htm
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http://www.chuden.co.jp/e-museum/denkiarekore/knowledge/trip/housing/renzi.html
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mechanism of microwave oven in Internet (4)
Electrical Appliances Around Us http://contest.thinkquest.jp/tqj2002/50504/Rsikumi2.htm
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http://www.topics.or.jp/rensai/sadako/2000/page13.html http://www.topics.or.jp/rensai/sadako/2000/page13.html

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http://www.iee.or.jp/emf/renji2.htm http://www.iee.or.jp/emf/renji2.htm
mechanism of microwave oven in Internet (6)


Internet search

• Indivisible series of words should be shown by quotation marks (") difference between ""
• "NOT" can be shown by "- (hyphen)"
- -
strict searching: Use "+".
Internet search

• Indivisible series of words should be shown by quotation marks (") difference between ""
• "NOT" can be shown by "- (hyphen)"
- -
strict searching: Use "+".

""
comments on this lecture and question
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