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Saturday, May 14, 2011
“Five Minds for the Future” written by Howard Gardner.
Inspiring Thoughts By Dr.APJ Abdulkalam
has not yet happened
but it certainly will happen.
transform a child into a
leader- the transformatino from
‘what can you do for me’ to
‘what can i do for you’.
are booked and registered.
reside on your shoulders.
on the earth,
above the earth and
under the earth.
more important than the
education received in college
and university.
of the young.
autonomous learner.
finding the right
answers through hard
work and research into
laws of nature.
exclusively for book reading and
in a few years you will become a
knowledge centre
Sunday, May 8, 2011
New Material Derived From Graphene May Have Many Applications In Future Electronics
(Graphane crystal. This novel two-dimensional material is obtained from graphene (a monolayer of carbon atoms) by attaching hydrogen atoms (red) to each carbon atoms (blue) in the crystal. (Credit: Image courtesy of University of Manchester)
— Researchers at The University of Manchester have produced a ground-breaking new material, graphane, which has been derived from graphene.
Graphene, which was discovered at the University in 2004, is a one-atom-thick crystal with unusual highly conductive properties, which has quickly become one of the hottest topics in physics and materials science. It is also tipped for a number of future applications in electronics and photonics.
But research published January, 30, 2009 by Professor Andre Geim and Dr Kostya Novoselov, who led the group that discovered graphene in 2004, suggests its uses could be far greater.
That's because the scientists, from the University’s School of Physics and Astronomy, have found that graphene will react with other substances to form new compounds with different properties - opening up further opportunities for development in the field of electronics.
As part of the research, published in the journal Science, Professor Geim and Dr Novoselov have used hydrogen to modify highly conductive graphene into a new two-dimensional crystal - graphane.
The addition of a hydrogen atom on each of the carbon atoms in the graphene achieved the new material without altering or damaging the distinctive one-atom-thick ‘chicken wire’ construction itself.
But instead of being highly conductive, like graphene, the new substance graphane has insulating properties.
The researchers say the findings demonstrate that the material can be modified using chemistry - clearing the way for the discovery of further graphene-based chemical derivatives.
“Graphene is an excellent conductor and is tipped for many electronic applications,” said Dr Novoselov. “However it was tempting to look at ways to gain additional control of its electronic properties through the use of chemistry.
“Our work proves that this is a viable route and hopefully will open the floodgates for other graphene-based chemical derivatives. This should widen the possible applications dramatically.”
The unique electronic properties of graphene have already led researchers to look at ways the material could be used in the development of increasingly small and fast transistors. However, the absence of the energy gap in the electronic spectra forced scientists to use rather complex graphene-based structures like quantum point contacts and quantum dots for this purpose.
The discovery that graphene can be modified into new materials, fine tuning its electronic properties, has opened up the increasingly rich possibilities in the development of future electronic devices from this truly versatile material.
Professor Geim said: “The modern semiconductor industry makes use of the whole period table: from insulators to semiconductors to metals.
“But what if a single material is modified so that it covers the entire spectrum needed for electronic applications?
“Imagine a graphene wafer with all interconnects made from highly conductive, pristine graphene whereas other parts are modified chemically to become semiconductors and work as transistors.”
The Manchester researchers produced high-quality crystals of graphane by exposing pristine graphene to atomic hydrogen. The approach shows a way of making many other ultra-thin crystalline materials based on graphene
Graphene, which was discovered at the University in 2004, is a one-atom-thick crystal with unusual highly conductive properties, which has quickly become one of the hottest topics in physics and materials science. It is also tipped for a number of future applications in electronics and photonics.
But research published January, 30, 2009 by Professor Andre Geim and Dr Kostya Novoselov, who led the group that discovered graphene in 2004, suggests its uses could be far greater.
That's because the scientists, from the University’s School of Physics and Astronomy, have found that graphene will react with other substances to form new compounds with different properties - opening up further opportunities for development in the field of electronics.
As part of the research, published in the journal Science, Professor Geim and Dr Novoselov have used hydrogen to modify highly conductive graphene into a new two-dimensional crystal - graphane.
The addition of a hydrogen atom on each of the carbon atoms in the graphene achieved the new material without altering or damaging the distinctive one-atom-thick ‘chicken wire’ construction itself.
But instead of being highly conductive, like graphene, the new substance graphane has insulating properties.
The researchers say the findings demonstrate that the material can be modified using chemistry - clearing the way for the discovery of further graphene-based chemical derivatives.
“Graphene is an excellent conductor and is tipped for many electronic applications,” said Dr Novoselov. “However it was tempting to look at ways to gain additional control of its electronic properties through the use of chemistry.
“Our work proves that this is a viable route and hopefully will open the floodgates for other graphene-based chemical derivatives. This should widen the possible applications dramatically.”
The unique electronic properties of graphene have already led researchers to look at ways the material could be used in the development of increasingly small and fast transistors. However, the absence of the energy gap in the electronic spectra forced scientists to use rather complex graphene-based structures like quantum point contacts and quantum dots for this purpose.
The discovery that graphene can be modified into new materials, fine tuning its electronic properties, has opened up the increasingly rich possibilities in the development of future electronic devices from this truly versatile material.
Professor Geim said: “The modern semiconductor industry makes use of the whole period table: from insulators to semiconductors to metals.
“But what if a single material is modified so that it covers the entire spectrum needed for electronic applications?
“Imagine a graphene wafer with all interconnects made from highly conductive, pristine graphene whereas other parts are modified chemically to become semiconductors and work as transistors.”
The Manchester researchers produced high-quality crystals of graphane by exposing pristine graphene to atomic hydrogen. The approach shows a way of making many other ultra-thin crystalline materials based on graphene
Scientists Strive to Replace Silicon With Graphene on Nanocircuitry
(In a technique known as thermochemical nanolithography, the tip of an atomic force microscope uses heat to turn graphene oxide into reduced graphene oxide, a substance that can be used to produce nanocircuits and nanowires with controllable conductivity. (Credit: University of Illinois at Urbana-Champaign)
Scientists have made a breakthrough toward creating nanocircuitry on graphene, widely regarded as the most promising candidate to replace silicon as the building block of transistors. They have devised a simple and quick one-step process based on thermochemical nanolithography (TCNL) for creating nanowires, tuning the electronic properties of reduced graphene oxide on the nanoscale and thereby allowing it to switch from being an insulating material to a conducting material.
The technique works with multiple forms of graphene and is poised to become an important finding for the development of graphene electronics. The research appears in the June 11, 2010, issue of the journal Science.
Scientists who work with nanocircuits are enthusiastic about graphene because electrons meet with less resistance when they travel along graphene compared to silicon and because today's silicon transistors are nearly as small as allowed by the laws of physics. Graphene also has the edge due to its thickness -- it's a carbon sheet that is a single atom thick. While graphene nanoelectronics could be faster and consume less power than silicon, no one knew how to produce graphene nanostructures on such a reproducible or scalable method. That is until now.
"We've shown that by locally heating insulating graphene oxide, both the flakes and epitaxial varieties, with an atomic force microscope tip, we can write nanowires with dimensions down to 12 nanometers. And we can tune their electronic properties to be up to four orders of magnitude more conductive. We've seen no sign of tip wear or sample tearing," said Elisa Riedo, associate professor in the School of Physics at the Georgia Institute of Technology.
On the macroscale, the conductivity of graphene oxide can be changed from an insulating material to a more conductive graphene-like material using large furnaces.
Now, the research team used TCNL to increase the temperature of reduced graphene oxide at the nanoscale, so they can draw graphene-like nanocircuits. They found that when it reached 130 degrees Celsius, the reduced graphene oxide began to become more conductive.
"So the beauty of this is that we've devised a simple, robust and reproducible technique that enables us to change an insulating sample into a conducting nanowire. These properties are the hallmark of a productive technology," said Paul Sheehan, head of the Surface Nanoscience and Sensor Technology Section at the Naval Research Laboratory in Washington, D.C.
The research team tested two types of graphene oxide -- one made from silicon carbide, the other with graphite powder.
"I think there are three things about this study that make it stand out," said William P. King, associate professor in the Mechanical Science and Engineering department at the University of Illinois at Urbana-Champaign. "First, is that the entire process happens in one step. You go from insulating graphene oxide to a functional electronic material by simply applying a nano-heater. Second, we think that any type of graphene will behave this way. Third, the writing is an extremely fast technique. These nanostructures can be synthesized at such a high rate that the approach could be very useful for engineers who want to make nanocircuits."
"This project is an excellent example of the new technologies that epitaxial graphene electronics enables," said Walt de Heer, Regent's Professor in Georgia Tech's School of Physics and the original proponent of epitaxial graphene in electronics. His study led to the establishment of the Materials Research Science and Engineering Center two years ago. "The simple conversion from graphene oxide to graphene is an important and fast method to produce conducting wires. This method can be used not only for flexible electronics, but it is possible, sometime in the future, that the bio-compatible graphene wires can be used to measure electrical signals from single biological cells."
Friday, May 6, 2011
An inspirational speech BY APJ
in India
so embarrassed to recognize our own strengths, our achievements?
We are such a great nation. We have so many amazing success stories but we
refuse to acknowledge them. Why?
We are the first in milk production.
We are number one in Remote sensing satellites.
We are the second largest producer of wheat.
We are the second largest producer of rice.
Look at Dr. Sudarshan , he has transferred the tribal village into a
self-sustaining, self-driving unit. There are millions of such achievements but
our media is only obsessed in the bad news and failures and disasters.
I was in Tel Aviv once and I was reading the Israeli newspaper. It was the day
after a lot of attacks and bombardments and deaths had taken place. The Hamas
had struck. But the front page of the newspaper had the picture of a Jewish
gentleman who in five years had transformed his desert into an orchid and a
granary. It was this inspiring picture that everyone woke up to. The gory
details of killings, bombardments, deaths, were inside in the newspaper, buried
among other news.
In
sickness, terrorism, crime.. Why are we so NEGATIVE? Another question: Why are
we, as a nation so obsessed with foreign things? We want foreign T.Vs, we want
foreign shirts. We want foreign technology.
Why this obsession with
everything imported. Do we not realize that self-respect comes with
self-reliance? I was in
giving this lecture, when a 14 year old girl asked me for my autograph. I asked
her what her goal in life is. She replied: I want to live in a developed
. For her, you and I will have to build this developed
is not an under-developed nation; it is a highly developed nation.
YOU say that
our government is inefficient.
YOU say that our laws are too old.
YOU say that the municipality does not pick up the garbage.
YOU say that the phones don't work, the railways are a joke. The airline is the
worst in the world, mails never reach their destination.
YOU say that our country has been fed to the dogs and is the absolute pits.
YOU say, say and say. What do
YOU do about it?
Take a person on his way to
Give him a name - 'YOURS'. Give him a face - 'YOURS'. YOU walk out of the
airport and you are at your International best. In
butts on the roads or eat in the stores. YOU are as proud of their Underground
links as they are. You pay $5 (approx. Rs. 60) to drive through Orchard Road
(equivalent of Mahim Causeway or Pedder Road) between 5 PM and 8 PM. YOU come
back to the parking lot to punch your parking ticket if you have over stayed in
a restaurant or a shopping mall irrespective of your status identity In
you don't say anything, DO YOU? YOU wouldn't dare to eat in public during
Ramadan, in
. YOU would not dare to go out without your head covered in Jeddah.
YOU would not dare to buy an employee of the telephone exchange in London at 10
pounds (Rs.650) a month to, 'see to it that my STD and ISD calls are billed to
someone else.'YOU would not dare to speed beyond 55 mph (88 km/h) in Washington
and then tell the traffic cop, 'Jaanta hai main kaun hoon (Do you know who I
am?). I am so and so's son. Take your two bucks and get lost.' YOU wouldn't
chuck an empty coconut shell anywhere other than the garbage pail on the beaches
in
.
Why don't YOU spit Paan on the streets of
Why don't YOU use examination jockeys or buy fake certificates in
talking of the same YOU. YOU who can respect and conform to a foreign system in
other countries but cannot in your own. You who will throw papers and
cigarettes on the road the moment you touch Indian ground. If you can be an
involved and appreciative citizen in an alien country, why cannot you be the
same here in
In an interview, the famous
Ex-municipal commissioner of
Mr. Tinaikar, had a point to make. 'Rich people's dogs are walked on the
streets to leave their affluent droppings all over the place,' he said. 'And
then the same people turn around to criticize and blame the authorities for
inefficiency and dirty pavements. What do they expect the officers to do? Go
down with a broom every time their dog feels the pressure in his bowels?
In
every dog owner has to clean up after his pet has done the job. Same in
Will the Indian citizen do that here?' He's right. We go to the polls to choose
a government and after that forfeit all responsibility.
We sit back wanting to be pampered and expect the government to do everything
for us whilst our contribution is totally negative. We expect the government to
clean up but we are not going to stop chucking garbage all over the place nor
are we going to stop to pick a up a stray piece of paper and throw it in the
bin. We expect the railways to provide clean bathrooms but we are not going to
learn the proper use of bathrooms.
We want Indian Airlines and Air
to provide the best of food and toiletries but we are not going to stop
pilfering at the least opportunity.
This applies even to the staff who is known not to pass on the service to the
public.
When it comes to burning social
issues like those related to women, dowry, girl child! and others, we make loud
drawing room protestations and continue to do the reverse at home. Our excuse?
'It's the whole system which has to change, how will it matter if I alone
forego my sons' rights to a dowry.' So who's going to change the system?
What does a system consist of? Very conveniently for us it consists of our
neighbours, other households, other cities, other communities and the
government. But definitely not me and YOU. When it comes to us actually making
a positive contribution to the system we lock ourselves along with our families
into a safe cocoon and look into the distance at countries far away and wait
for a Mr.Clean to come along & work miracles for us with a majestic sweep
of his hand or we leave the country and run away.
Like lazy cowards hounded by our fears we run to
praise their system. When
insecure we run to
. When
experiences unemployment, we take the next flight out to the Gulf. When the
Gulf is war struck, we demand to be rescued and brought home by the Indian
government. Everybody is out to abuse and rape the country. Nobody thinks of
feeding the system. Our conscience is mortgaged to money.
Dear Indians, The article is
highly thought inductive, calls for a great deal of introspection and pricks
one's conscience too . I am echoing J. F. Kennedy's words to his fellow
Americans to relate to Indians ..
'ASK WHAT WE CAN DO FOR
ARE TODAY'
Lets do what
needs from us.
Jai Hind