News tagged with high pressure
Scientists predict an out-of-this-world kind of ice
(PhysOrg.com) -- Cornell scientists are boldly going where no water molecule has gone before -- that is, when it comes to pressures found nowhere on Earth.
Jan 17, 2012 |
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Probing hydrogen under extreme conditions
(Phys.org) -- How hydrogen--the most abundant element in the cosmos--responds to extremes of pressure and temperature is one of the major challenges in modern physical science. Moreover, knowledge gleaned ...
Apr 13, 2012 |
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Study resolves century-long debate over how to describe electromagnetic momentum density in matter
(PhysOrg.com) -- Researchers from the NIST Center for Nanoscale Science and Technology and the University of British Columbia have shown that the interaction between a light pulse and a light-absorbing object, including the ...
Dec 29, 2011 |
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Part of Earth's mantle shown to be conductive under high pressure and temperatures
(PhysOrg.com) -- Scientists studying the rotation of the Earth have long known that our planet doesn't have a perfect spin. Most believe this is due to the different types of materials that make up the core, mantle and crust, ...
Jan 20, 2012 |
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The high winds of the upper atmosphere contain less renewable energy than previously assumed
It seems that the energy mix of the future will have to differ from the current suggestions of some visionaries. This is because the jet streams that sweep the upper atmosphere with high winds would yield ...
Technology / Energy & Green Tech
Dec 12, 2011 |
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How diamonds emerge from graphite
Scientists have used a new method to precisely simulate the phase transition from graphite to diamond for the first time. Instead of happening concerted, all at once, the conversion evidently takes place in ...
Sep 21, 2011 |
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Gas hydrate strategy reinforced
Their critics weren't convinced the first time, but Rice University researchers didn't give up on the "ice that burns."
Space & Earth / Earth Sciences
Sep 15, 2011 |
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Oxygen molecule survives to enormously high pressures
Using computer simulations, a Ruhr-University Bochum (Germany) researcher has shown that the oxygen molecule (O2) is stable up to pressures of 1.9 terapascal, which is about nineteen million times higher than atmosphere pressure. ...
Jan 30, 2012 |
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System to deliver organ transplant drug -- without harmful side effects
A new system for delivering a drug to organ transplant patients, which could avoid the risk of harmful side effects, is being developed by scientists at the University of Strathclyde in Glasgow.
Nanotechnology / Bio & Medicine
Jan 26, 2012 |
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New method to clean and treat polluted water for extraction of chemicals
Scientists in Poland have discovered that it is easy to clean and treat polluted water for extraction of valuable chemicals, such as those used in the production of drugs. The upshot of this is that the use ...
Feb 24, 2012 |
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Understanding methane's seabed escape
A shipboard expedition off Norway, to determine how methane escapes from beneath the Arctic seabed, has discovered widespread pockets of the gas and numerous channels that allow it to reach the seafloor.
Space & Earth / Earth Sciences
Sep 19, 2011 |
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High pressure kills pathogens, maintains green onions' taste and color
Green onions cause about five percent of outbreaks of food poisoning from produce, worldwide. Now a team of researchers from the University of Delaware, Newark, shows that high pressure treatment of green onions can kill ...
Mar 20, 2012 |
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High pressure
High pressure science and engineering is studying the effects of high pressure on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By high pressure it is usually meant pressures of thousands (kilobars) or millions (megabars) of times atmospheric pressure (about 1 bar).
It was by applying high pressure as well as high temperature to carbon that man-made diamonds were first produced as well as many other interesting discoveries. Almost any material when subjected to high pressure will compact itself into a denser form, for example, quartz, also called silica or silicon dioxide will first adopt a denser form known as coesite, then upon application of more temperature, form stishovite. These two forms of silica were first discovered by high pressure experimenters, but then found in nature at the site of a meteor impact.
Chemical bonding is likely to change under high pressure, when the P*V term in the free energy becomes comparable to the energies of typical chemical bonds - i.e. at around 100 GPa. Among the most striking changes are metallization of oxygen at 96 GPa (rendering oxygen a superconductor), and transition of sodium from a nearly-free-electron metal to a transparent insulator at ~200 GPa. At ultimately high compression, however, all materials will metallize.[citation needed]
High pressure experimentation has led to the discovery of the types of minerals which are believed to exist in the deep mantle of the Earth, such as perovskite which is thought to make up half of the Earth's bulk, and post-perovskite, which occurs at the core-mantle boundary and explains many anomalies inferred for that region.[citation needed]
Pressure "landmarks": pressure exerted by a fingernail scratching is ~0.6 GPa, typical pressures reached by large-volume presses are up to 30-40 GPa, pressures that can be generated inside diamond anvil cells are ~320 GPa, pressure in the center of the Earth is 364 GPa, highest pressures ever achieved in a shock waves are over 100,000 GPa.[citation needed]
For more information about High pressure, read the full article at
Wikipedia.
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