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hello dear students welcome to a very
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special course on introduction to
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nanoscience and nanotechnology i am
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doctor purvey zamath and this is the
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first lecture of the course
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so in this first lecture uh we will
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start uh from the very basic definitions
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of the nano
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so let's proceed towards today's lecture
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so whenever we heard the word nano so we
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have the question in mind that what is
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mean
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nano so be remember
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the word nano mean
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one billionth i mean nano by itself is
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nothing but it's actually the free facts
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and this pre-packs mean 10 raised to the
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power
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9 so whatever you uh you attach i mean
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you attach gram you attach a meter or
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you attach anything else uh after the
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nano so it would mean uh 10 raised to
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power and -9 of that particular thing so
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if you let's suppose if you want to
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attach meter
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uh after nano are you put a prefix nano
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before the meter so it will mean uh
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nanometers so if you teach gram
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uh after the nano so it would means uh
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nanogram and so on so what actually nano
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nanometer means a nanometer means one
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billionth of amp meters so just like
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that after you put some things else i
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mean instead of meter you put a gram so
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it would mean nanograms a nanogram would
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mean one billionth of a gram similarly
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if you put i means
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second i mean that is for the time and
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you say that you have instead of meter
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you say you have
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nanoseconds so nanosecond would mean one
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billionth of a
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meter so in scientific terms i mean
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you want to have uh the scales of nano
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in term of
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scientific terminologies for example in
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science we have
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uh i mean
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we have human hair
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so if we refer
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the length scale that that of nano in
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term of a human hair
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so a human hair has the diameters as
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small as
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10 000 nanometer so that's how
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scientifically you relates the length of
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a human hair and it is this is the
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typical
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uh same image of the human hair so this
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is the brief introductions of a nano so
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let me let me uh try it again
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let me repeat it again what is mean by
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nano uh nano by itself is a basically a
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prefix uh which means uh one billionth
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so this prefix furth
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is with a meter so it would mean
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nanometer and nanometer mean one billion
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up a meter similarly if you would take
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that pre-packs with the uh
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with the times unit that is cycling so
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it would mean nanosecond in nanosecond
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would mean
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one billionth of a second if you would
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take that with a gram so it would mean a
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nanogram in nanogram would mean one
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billionth of a
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gram and scientifically if you you
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utilize uh the term nano and you want to
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admire something uh that is well known
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to you for example the human hair so uh
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the diameter of human hair is equal to
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10 000 uh nanometers so let's be a more
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a bit more specific about the nano so
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for that you can consider the example of
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a child you can see it here in this
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particular figure so here you can see
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that this child uh
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at height the height of this child is
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about
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uh
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one meter
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and if you consider
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if you put that one
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uh meter and two
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nanometer so it would equal to 1 billion
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nanometers i mean that is how you
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convert the scale i mean you're already
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familiar with the convergence of the
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scales and your basic class i mean while
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you were doing your matriculation so you
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are familiar with the uh si system
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uh and you also know that how to convert
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uh the scales uh amines and different
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multiples so uh i mean one meter height
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of this child if you convert that into a
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scale of nano so it would be equal to
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uh one billion nanometers so there uh
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here you can see
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uh a typical ruler
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and this ruler you can see that you can
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start it here from
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one meter which we took it here for
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uh the the height of a head so one meter
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is basically equal to uh one billionth
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nanometer
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and here if we just want to put that in
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a power of 10
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so here you can see that uh one meter is
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equal to uh 10 raised to power 0 meter
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and then uh you have 10 centimeters so
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10 centimeter is equal to 10 raised to
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power minus 1 meter
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and if you proceed again toward the
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smaller one that is one centimeter so
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one centimeter is 10 raised to power
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minus 2 meter
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and again
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you're proceeding towards the smallest
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uh so 1 millimeter 1 millimeter 10 is to
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power minus 3 meter
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then you have 100 micrometer and that is
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equal to 10 raised to power minus 4
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meter then you have
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uh 10 micrometers and 10 micrometers is
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equal to 10 raised to power minus 5
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meters then 1 micrometers and 1
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micrometer that is equal to 10 raised to
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the power minus x then 100 nanometers
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and 100 nanometer is equal to 10 raised
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to the power minus
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7 meters
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then 10 raised
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10 nanometers and 10 nanometer is equal
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to 10 raised to power minus 8
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meters
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and then we have one nanometer and one
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nanometer is equal to 10 raised to power
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minus 9 meters
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and if we proceed toward further smaller
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length that is up to 0.1 nanometers so
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that is equal to 10 raised to power
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minus 10 meter which is the diameter of
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a hydrogen
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atom so that is how you proceed from
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bigger
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towards the smallest i mean you start
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from the height of a kid and you proceed
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towards the diameter of the atom and
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that is how you you observe that how the
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length scale uh i mean it's changes from
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a bigger one to uh the smallest one and
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if you consider for uh the nano that
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that that we could consider further in
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this lecture
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nano now basically whenever we refer to
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a narrow something uh which we call the
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nano so that will basically lie between
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range from
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this one i mean from this particular
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point uh up to this particular scale
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that is if something has uh a length and
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between the scale that is from 10 raised
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to the power -7 to 10 raised to power
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minus 9 meter uh
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so that we will call that lies in the
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nano but that is necessary for uh i mean
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for an object which should have at least
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one dimension in this particular region
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so we will call that as a nano object or
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we will call that an
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nano events or we will call that uh a
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nano uh quantity are
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nano things
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so what is nano technology so let's we
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have a formal definitions for uh the
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nano technology uh you already know
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about the technology that what
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technology is you mean that's the
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techniques uh i means uh and the best of
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the knowledge trying to do something to
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develop something i mean normally you
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you are really familiar with the with
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the term uh technology
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so uh when we have the prefix uh nano
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before the technology so again the
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definitions uh it had a bit change
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so uh how we have the proper definitions
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or we can say that a formal definitions
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for the nanotechnology so the problem
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definition for the nanotechnology will
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look like this
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uh that uh it's a field of applied
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science
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uh in which we focused on designs
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formations
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identifications
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and applications of materials and
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devices on the nano scales i mean this
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this is the thing which we should have
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i mean the above from here up to this
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point i mean this this is the general
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definition for uh the technology i mean
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so whenever you heard the words
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technology so a technology you means i
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feel like applied design focus on
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designs formation identifications
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and application and application of
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materials and devices i mean to this
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accents we have this as a definitions
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for
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are the technology
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but uh if you proceed further that is we
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saying that on the nanoscale
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so
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then the technology is converted into
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nanotechnology so what actually it means
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uh what is mean by nanotechnology and
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nanotechnologies mean that something
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or
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some event or some applications we want
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to try at a nanoscale that is uh between
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uh one two hundred nanometers i mean
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whatever we trying to do or whatever we
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we intend to do
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in a smaller scale with at least one
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dimension in the range of one two
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hundred nanometers so we call that uh we
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call that it lies in the field of
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nanotechnology and we remember here we
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have one thing that is a field of
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applied science i mean we have the
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sciences like we have biology uh we have
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chemistry we have physics i mean
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all of these that that there are
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sciences but out of these sciences some
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of the sciences i mean uh these are
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those uh where can be which can be
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applied in a practical life so here uh
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nanotechnology is basically the applied
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field of science and we remember later
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on we will define it in full detail
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that nanotechnology it counts
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all the uh the science is here i mean
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it's uh it's combined the physics with
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biology uh it combined chemistry with
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the physics uh
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it combined computer science with the
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physics and so on uh in short for we can
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say that it's a multi-disciplinary field
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i mean where we unite all the field and
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to a single field i mean by itself since
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simply we can say that
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uh nanotechnology by itself
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it's not a new field it's basically a
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field that is the combinations of all
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the other fields i mean it's include
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physics it's include chemistry include
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biology it can include computer science
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it includes engineering and even in some
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action we can say that it also include
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the fine arts so uh this is something uh
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informally you have about the
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nanotechnology so that is what is
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nanotechnology all the technology that
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we want to develop or we want to do or
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we want to accelerate or we want to
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focus
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uh
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at a nanoscale so
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uh that massively means
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nanotechnology i mean the technology
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that you want to do or you want to apply
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or you want to develop at the nano scale
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so we call that
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nano technology so the only difference
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is the scale
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so now we have the questions
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that uh we define nanotechnology
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we mentioned uh some important fact
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about nanotechnology
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and we also mentioned about
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that what actually the materials that we
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call
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nanomaterials are
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so now the question is that how we can
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make the nanomaterial or how we can
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synthesize the nanomaterials or in short
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terms what are the methods of making the
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nanomaterials or the nanoparticles so
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we basically have two big approaches the
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first one is called the top down
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are the top-down methods so what
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actually we if we do in this methods uh
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in this technique normally we have uh
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some uh a big object or we have a heavy
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object and that heavy object or big size
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object we cut it into smaller and
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smaller pieces until we reach to the
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nanoscale region or we we reach to the
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nanoscale uh dimensions so that is
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called top down
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approach i mean we we get the thing and
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a bigger size and a bulk i mean a larger
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size and we cut it down to a smaller
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scale and then we have another approach
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which is called bottom up so what is
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mean by the bottom up uh bottom up mean
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that
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we have atoms and these atoms we put
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together
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one by ones until we reach to
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uh the nanoscale dimension that is we
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develop the bigger object by
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combinations of the atom i mean we put
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the atom
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side by side until we reach the
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dimension between 1 to 100 nanometers
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and we remember for the nano materials
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uh i mean it's it's compulsory that they
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should have at least one dimension in
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the range of uh 1 to 100 nanometer so uh
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what we have in short in short
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if we have a big object and we cut that
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into pieces to bring it into nanoscale
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regions so that particular method is
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called top-down methods
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and
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bottom-up approach our bottom-up
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technique is the one in which we combine
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atoms side by side uh we want to grow a
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materials from a smaller scales until we
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reach to
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the nano scales
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dimensions so that technique
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where we put atom side by side and grow
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a bigger size material so that it can
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lie in the range of 100 nanometer
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uh with at least one dimensions
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in that particular
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range uh we call that a bottom up
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approach i mean we are we are growing
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the material from the atomic scale and
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the top-down approach mean that we are
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we are cutting down the material from a
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bigger size to the nanoscale region so
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these are the two basic techniques for
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the growth of
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the nanomaterials
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so here you are in this particular
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figure you can see a lot of example
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everyday life example
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of nanoscale things or nanoscale
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materials i mean here you can see uh
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the scale of nano things are nanometer
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and more i mean here you can see that
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it's a dust mite and dust mite you can
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see that the scale is uh 200 micrometers
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and here you say we have an end and this
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is the feed the feet of an and and you
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you see here is almost approximately 5
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micrometers
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and here you can see human here human
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hair has a diameter
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in the range of approximately 60 to 120
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micrometers
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apply ash apply ash is approximately
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from 10 to 20 micrometer
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red blood cell is approximately from
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seven to eight micrometer i mean here
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you can see different object
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and on this side you can see as well
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a head have a pen that is from one to
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two millimeters
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i mean against here there there are so
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many things uh and you can see here
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uh the scale as well
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this is the same self-assembled
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natural inspired structures
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that is how many tens of nanometers
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and here you can see nanotubes nanotubes
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of the electrode that i mean the
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well-known nanomaterials that we call
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carbon nanotubes so carbon nanotubes can
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have a diameter approximately 1.3
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nanometers i mean they can have smaller
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you can grow
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nanomaterials i mean the well-known
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nanomaterials the carbon nanotubes you
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can grow that in the laboratory and they
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can have a typical size are the
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diameters uh that's that that lie in the
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range of approximately
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1.3 nanometer similarly you can have uh
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buckyball buckyball is also one can of
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carbon nanomaterials very famous carbon
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nanomaterials and buckyball can have a
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diameter approximately one
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nanometer so just like that you have
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many many narrow materials that we will
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discuss in the coming lecture
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so i think this is all we have uh for
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this lecture i mean it's somehow a short
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introductions of the term
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nano so you have to stay tuned with the
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next lecture
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that should be the next the next lecture
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will be lecture number two and that
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lectures uh we will further explain the
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term nano
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and we will try to explain
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that why
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nano is interesting i mean that is that
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that will be the key theme of the next
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lecture i mean in the first lecture we
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just explained
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the meaning of the nano now in the
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coming lecture that is lecture number
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two in that lecture we will explain why
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nano is interesting
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i mean why we are taking so much and
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trust in the nano so that will be the
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key theme of the next lecture so stay
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tuned with the next lecture till then
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bye bye
