Saturday, 29 July 2017

Great news for SEE students

Dear Students
Scientific Nepal is a project launched to create a mega platform for all activities related to science and technologies conducted in Nepal as well as to facilitate students by providing easy learning platform for science and mathematics for all levels. This year we are going to help you for your SEE preparation in a convenient way. You will get learning materials as well as interaction platform for Science and Optional Mathematics.
How can you take advantage from this module?
We believe in one motto “Slow and steady wins the race”. Students  generally try to take all the burden of course at a same time which make their study lengthy as well as cumbersome. We are going to help you to change this study pattern and  learning  easy.
Everyday we will give five to ten questions which you can solve and learn within thirty minutes. If you continue practicing this  everyday, you will be able to get excellent grade without any difficulties.
In Optional mathematics we will provide five to ten questions based on same method. You will get one solved problem and other problems which can be solved by similar method.
Every weekend you will get a model question paper from which you can measure your learning process as well.
Very soon we are going to launch “Solution on demand” module in which you can get instant solution for the questions that you find hard to solve.
Very soon we will launch video classes also.
If you have some idea, feel free to contact us. You can leave your suggestions in comment box.
Your class will  start from tomorrow.
Mahesh Sagar Khanal
` Scientific Nepal

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Monday, 7 January 2013

seminar in kathmandu

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Saturday, 21 July 2012

Stars draw atoms closer together

Magnetism may be the secret to a strong marriage between atoms in the atmospheres of stars. Computer simulations show that a previously unknown type of powerful chemical bond should be induced by the stars’ ferocious magnetic fields. If the effect can be harnessed in the lab, ‘magnetized matter’ could be exploited for quantum computing.
Chemists identify two classes of strong molecular bonds: ionic bonds, in which electrons from one atom hop over to another, and covalent bonds, in which electrons are shared between atoms. But Trygve Helgaker, a quantum chemist at the University of Oslo, and his colleagues accidentally discovered a third bonding mechanism when they simulated how atoms should behave under magnetic fields of about 105 tesla — 10,000 times the biggest fields that can be generated on Earth. Their results are published in Science today1.
White-dwarf stars have huge magnetic fields that could force molecular bonds into powerful new modes.
NASA/ESA/H. Bond (STScI)/M. Barstow (Univ. Leicester)
The team first examined how the lowest energy state, or ground state, of a two-atom hydrogen molecule was distorted by the magnetic field. The dumb-bell-shaped molecule oriented itself parallel to the direction of the field and the bond became shorter and more stable, says Helgaker. When one of the electrons was boosted to an energy level that would normally break the bond, the molecule simply flipped so that it was perpendicular to the field and stayed together.
“We always teach students that when an electron is excited like this, the molecule falls apart,” says Helgaker. “But here we see a new type of bond keeps the atoms hanging together.” The team also reports that a similar effect should occur between helium atoms, which normally don't bond at all.
The atoms are held together by the way their electrons dance around the magnetic-field lines, explains Helgaker. “The way electrons move relative to the field, and their kinetic energy, can become as important for chemical bonding as the electrostatic attraction between the electrons and the nuclei,” he says. Depending on their geometry, molecules will turn to allow electrons to rotate around the direction of the magnetic field.

Star field

If the new states remain bound at very high temperatures, they could well exist in the atmospheres of some white dwarfs and neutron stars, where the magnetic fields are similar to those simulated by the team. But it will be difficult to spot them, says Dong Lai, an astrophysicist at Cornell University in Ithaca, New York. The team will need to extend its model to see whether the unusual bonding states would modify the spectra of light coming from the stars in a way that can be detected, he says. The simulation of the states “is an important step, but several more are needed to see how relevant this is in astrophysics”.
Closer to home, it is virtually impossible to generate such high magnetic fields, because they are accompanied by drastic changes in the chemistry of everything affected by them. The bond length between atoms can shrink by around 25% under such high fields, says Helgaker. “The experimental apparatus would cease to be an apparatus in these extreme conditions!”
Nevertheless, the findings boost hopes that ‘magnetized matter’ in the lab could have properties that may be exploited.
In 2009, physicists created a weakly bound state called a Rydberg molecule2, which some people have suggested could be used to carry information in a quantum computer. Rydberg molecules are highly sensitive to magnetic effects, says Chris Greene, an atomic physicist at the University of Colorado Boulder, who was one of the first people to posit the molecules' existence3. “That means we could use magnetic fields as a knob to tightly control the strength of the binding, to manipulate them to store and erase quantum memory as needed.”
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