PRESENTATION ON PHYSICS PRESENTATION ON PHYSICS CONTENTS SURFACE TENSION. VISCOSITY.
Presentation on Nanotechnogy
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Transcript of Presentation on Nanotechnogy
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8/2/2019 Presentation on Nanotechnogy
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Presentation on Nanotechnogy
Presented by,
Dilip PandeyShruti Pai
Siddharth Shinde
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What is Nanotechnology?
Nanotechnology is the study of manipulating matter
on an atomic and molecular scale. Generally,nanotechnology deals with developing materials,
devices, or other structures possessing at least one
dimension sized from 1 to100 nanometres.
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Environmental benefits of
nanotechnology
Energy
Nanotechnology could potentially have a
great impact on clean energy production.
Research is underway to use nanomaterials
for purposes including more efficient solar
cells, practical fuel cells, and environmentally
friendly batteries.
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Water filtration and remediation
A strong influence of nanochemistry on
waste-water treatment, air purification and
energy storage devices is to be expected.
Mechanical or chemical methods can be used
for effective filtration techniques. One class of
filtration techniques is based on the use of
membranes with suitable hole sizes, whereby
the liquid is pressed through the membrane.
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Impact of Nanotechnology
Nanopollution
Nanopollution is a generic name for all wastegenerated by nanodevices or duringthe nanomaterials manufacturing process. This kind of
waste may be very dangerous because of its size. It canfloat in the air and might easily penetrate animal andplant cells causing unknown effects. Most human-madenanoparticles do not appear in nature, so livingorganisms may not have appropriate means to deal
with nanowaste. It is probably one great challengeto nanotechnology: how to deal with itsnanopollutants and nanowaste.
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Bioaccumulation
Bioaccumulation refers to the accumulation ofsubstances, such as pesticides, or other organicchemicals in an organism.
Bioaccumulation occurs when an organismabsorbs a toxic substance at a rate greater thanthat at which the substance is lost. Thus, thelonger the biological half-life of the substance the
greater the risk of chronic poisoning, even ifenvironmental levels of the toxin are not veryhigh.
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Nanoparticles
Nanoparticles present possible dangers, both
medically and environmentally. Most of these
are due to the high surface to volume ratio,
which can make the particles very reactive
or catalytic. They are also able to pass
through cell membranes in organisms, and
their interactions with biological systems arerelatively unknown.
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Problems Life cycle
To properly assess the health hazards of
engineered nanoparticles the whole life cycle
of these particles needs to be evaluated,
including their fabrication, storage and
distribution, application and potential abuse,
and disposal. The impact on humans or the
environment may vary at different stages ofthe life cycle.
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The Royal Society report identified a risk of
nanoparticles or nanotubes being released
during disposal, destruction and recycling, andrecommended that manufacturers of
products that fall under extended producer
responsibility regimes such as end-of-liferegulations publish procedures outlining how
these materials will be managed to minimize
possible human and environmental exposure
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Inhalation: Inhaled particles induceinflammation in respiratory tract,
causing tissue damage. Example:Inhalation of silica particles inindustrial workers causes silicosis.
Ingestion: nanoparticles may cause liverdamage. Ingested nanoparticles (i.e. for
oral drug delivery) have been found toaccumulate in the liver. Excessiveimmune/inflammatory responses causepermanent liver damage.
Potential human hazards for nanoscale particulates.
Dermal exposure: Particles may enter
body through the skin. Potentialhazards are unknown at present.
Other: ocular, .
Adapted from presentation of Vicki Colvin, Rice University.
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Red- and green-emittingquantum dots highlight the
mitochondria and nuclei,respectively, of human epithelialcells in culture. Although thesecolorful nanocrystals don't seemto harm the cells, could theypose unforeseen hazards to
people or the environment?
Silica-coated semiconductor nanocrystals are readily incorporated into a wide variety of eukaryotic
cells.
In experiments where the quantum dots are deposited on a collagen substrate and then cells are
deposited on top of this, the cells incorporate any quantum dots that underlie them
When the cells migrate on a substrate, they ingest all the dots they pass over providing a convenientand rapid way for assessing the cells' potential to metastasize, or spread (as a cancer) from one part
of the body to another [Adv. Mater., 14, 882 (2002)].
The dots appear to go into cells as "inert spectators." The cells remain healthy and even continue to
divide, with each cell division reducing the number of dots in any given cell. The dots have no
discernible effect on the cells.
---- A. Paul Alivisatos
Semiconductor nanoparticules.