Antigravics

http://www.physorg.com/news93200439.html

>> Sandia’s huge Z machine, which generates termperatures hottter than the sun, has turned water to ice in nanoseconds.

"The three phases of water as we know them — cold ice, room temperature liquid, and hot vapor — are actually only a small part of water’s repertory of states," says Sandia researcher Daniel Dolan. "Compressing water customarily heats it. But under extreme compression, it is easier for dense water to enter its solid phase [ice] than maintain the more energetic liquid phase [water]."

In the Z experiment, the volume of water shrank abruptly and discontinuously, consistent with the formation of almost every known form of ice except the ordinary kind, which expands. (One might wonder why this ice shrank instead of expanding, given the common experience of frozen water expanding to wreck garden hoses left out over winter. The answer is that only "ordinary" ice expands when water freezes. There are at least 11 other known forms of ice occurring at a variety of temperatures and pressures.)

"This work," says Dolan, "is a basic science study that helps us understand materials at extreme conditions."

But it has potential practical value. The work, which appears online March 11 in Nature Physics, was undertaken partly because phase diagrams that predict water’s state at different temperatures and pressures are not always correct — a fact worrisome to experimentalists working at extreme conditions, as well as those having to work at distances where direct measurement is impractical. For example, work reported some months ago at Z demonstrated that astronomers’ ideas about the state of water on the planet Neptune were probably incorrect.

Closer at hand, water in a glass could be cooled below freezing and remain water, in what is called a supercooled state.

Accurate knowledge of water’s behavior is potentially important for Z because the 20-million-ampere electrical pulses the accelerator sends through water compress that liquid. Ordinarily, the water acts as an insulator and as a switch. But because the machine is being refurbished with more modern and thus more powerful equipment, questions about water’s behavior at extreme conditions are of increasing interest to help avoid equipment failure for the machine or its more powerful successors, should those be built.

One unforeseen result of Dolan’s test was that the water froze so rapidly. The freezing process as it is customarily observed requires many seconds at the very least.

The answer, says Dolan, seems to be that very fast compression causes very fast freezing. At Z and also at Sandia’s nearby STAR (Shock Thermodynamic Applied Research) gas gun facility, thin water samples were compressed to pressures of 50,000-120,000 atmospheres in less than 100 nanoseconds. Under such pressures, water appears to transform to ice VII, a phase of water first discovered by Nobel laureate Percy Bridgman in the 1930s. The compressed water appeared to solidify into ice within a few nanoseconds.

Ice VII has nothing to do with ice-nine, an entirely fictional creation of author Kurt Vonnegut in his 1963 novel Cat’s Cradle. There, a few molecules of the invented substance acts as a precipitating seed to cause an extended chemical reaction that freezes almost all of Earth’s water. Ice VII, on the other hand, only stays frozen as long as it is under enormous pressure. The pressure relenting, the ice changes back to ordinary water.

Nucleating agents, of course, are often used to hasten sluggish chemical processes, such as when clouds are "seeded" with silver iodide to induce rain. Dolan already had demonstrated, as a graduate physics student at Washington State University, that water can freeze on nanosecond time scales in the presence of a nucleating agent.

However, the behavior of pure water under high pressure remained a mystery.

Sandia instruments observed the unnucleated water becoming rapidly opaque — a sign of ice formation in which water and ice coexist — as pressure increased. At the 70,000 atmosphere mark and thereafter, the water became clear, a sign that the container now held entirely ice.

"Apparently it’s virtually impossible to keep water from freezing at pressures beyond 70,000 atmospheres," Dolan says.

For these tests, Z created the proper conditions by magnetic compression. Twenty million amperes of electricity passed through a small aluminum chamber, creating a magnetic field that isentropically compressed aluminum plates roughly 5.5 by 2 inches in cross section. This created a shockless but rapidly increasing compression across a 25-micron-deep packet of water.

The multipurpose Z machine, whose main use is to produce data to improve the safety and reliability of the US nuclear deterrent, has compressed spherical capsules of hydrogen isotopes to release neutrons — the prerequisite for controlled nuclear fusion and essentially unlimited energy for humanity.

Source: Sandia National Laboratories >>

http://www.physorg.com/news156779157.html

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Lawrence Livermore National Laboratory scientists have shown that water, in hot dense environments, plays an unexpected role in catalyzing complex explosive reactions. A catalyst is a compound that speeds chemical reactions without being consumed. Platinum and enzymes are common catalysts. But water rarely, if ever, acts as a catalyst under ordinary conditions.

Detonations of high explosives made up of oxygen and hydrogen produce water at thousands of degrees Kelvin and up to 100,000 atmospheres of pressure, similar to conditions in the interiors of giant planets.

While the properties of pure water at high pressures and temperatures have been studied for years, this extreme water in a reactive environment has never been studied. Until now.

Using first-principle atomistic simulations of the detonation of the high explosive PETN (pentaerythritol tetranitrate), the team discovered that in water, when one hydrogen atom serves as a reducer and the hydroxide (OH) serves as an oxidizer, the atoms act as a dynamic team that transports oxygen between reaction centers.

"This was news to us," said lead researcher Christine Wu. "This suggests that water also may catalyze reactions in other explosives and in planetary interiors."

This finding is contrary to the current view that water is simply a stable detonation product.

"Under extreme conditions, water is chemically peculiar because of its frequent dissociations," Wu said. "As you compress it to the conditions you'd find in the interior of a planet, the hydrogen of a water molecule starts to move around very fast."

In the molecular dynamic simulations using the Lab's BlueGene L supercomputer, Wu and colleagues Larry Fried, Lin Yang, Nir Goldman and Sorin Bastea found that the hydrogen (H) and hydroxide (OH) atoms in water transport oxygen from nitrogen storage to carbon fuel under PETN detonation conditions (temperatures between 3,000 Kelvin and 4,200 Kelvin). Under both temperature conditions, this "extreme water" served both as an end product and as a key chemical catalyst.

For a molecular high explosive that is made up of carbon, nitrogen, oxygen and hydrogen, such as PETN, the three major gaseous products are water, carbon dioxide and molecular nitrogen.

But to date, the chemical processes leading to these stable compounds are not well understood.

The team found that nitrogen loses its oxygen mostly to hydrogen, not to carbon, even after the concentration of water reaches equilibrium. They also found that carbon atoms capture oxygen mostly from hydroxide, rather than directly from nitrogen monoxide (NO) or nitrogen dioxide (NO_). Meanwhile water disassociated and recombines with hydrogen and hydroxide frequently.

"The water that comes out is part of the energy release mechanism," Wu said. "This catalytic mechanism is completely different from previously proposed decomposition mechanisms for PETN or similar explosives, in which water is just an end product. This new discovery could have implications for scientists studying the interiors of Uranus and Neptune where water is in an extreme form."

More information: The research appears in the premier issue (April 2009) of the new journal Nature Chemistry.

Source: Lawrence Livermore National Laboratory >>>

http://www.physorg.com/news183732789.html

>> Most natural diamonds are formed at high-pressure, high-temperature conditions existing at depths of 87 to 120 miles in the Earth's mantle. Carbon-containing minerals provide the carbon source, and the growth occurs over periods from 1 billion to 3.3 billion years (25 percent to 75 percent of the age of the Earth).

In the recent research, the team measured the behavior of natural diamond crystals under shock-wave compression between 1 million and 10 million atmospheres of pressure, and the diamonds were crushed and melted in just a nanosecond (one billionth of a second).

"What we found is that diamond exhibits considerable strength right up to the point it melts," McWilliams said.

Earlier research conducted by Livermore scientists show that diamond melts at around 6 million atmospheres of pressure and 14,000 degrees Fahrenheit. >>>

Hydrogen peroxide decomposes (disproportionates) exothermically into water and oxygen gas spontaneously:

2 H2O2 → 2 H2O + O2

This process is thermodynamically favorable. It has a ΔHo of −98.2 kJ·mol−1 and a ΔGo of −119.2 kJ·mol−1 and a ΔS of 70.5 J·mol−1·K−1. The rate of decomposition is dependent on the temperature and concentration of the peroxide, as well as the pH and the presence of impurities and stabilizers. Hydrogen peroxide is incompatible with many substances that catalyse its decomposition, including most of the transition metals and their compounds. Common catalysts include manganese dioxide and silver. The same reaction is catalysed by the enzyme catalase, found in the liver, whose main function in the body is the removal of toxic byproducts of metabolism and the reduction of oxidative stress. The decomposition occurs more rapidly in alkali, so acid is often added as a stabilizer.

The liberation of oxygen and energy in the decomposition has dangerous side-effects. Spilling high concentrations of hydrogen peroxide on a flammable substance can cause an immediate fire, which is further fueled by the oxygen released by the decomposing hydrogen peroxide. High test peroxide, or HTP (also called high-strength peroxide) must be stored in a suitable,[citation needed] vented container to prevent the buildup of oxygen gas, which would otherwise lead to the eventual rupture of the container.

In the presence of certain catalysts, such as Fe2+ or Ti3+, the decomposition may take a different path, with free radicals such as HO· (hydroxyl) and HOO· being formed. A combination of H2O2 and Fe2+ is known as Fenton's reagent.

A common concentration for hydrogen peroxide is 20-volume, which means that, when 1 volume of hydrogen peroxide is decomposed, it produces 20 volumes of oxygen. A 20-volume concentration of hydrogen peroxide is equivalent to 1.667 mol/dm3 (Molar solution) or about 6%.

Hydrogen peroxide available at drug stores is three-percent solution. In such small concentrations, it is less stable, and decomposes faster. It is usually stabilized with acetanilide, a substance that has toxic side-effects in significant amounts.

Above roughly 70% concentrations, hydrogen peroxide can give off vapor that can detonate above 70 °C (158 °F) at normal atmospheric pressure.[citation needed] This can then cause a boiling liquid expanding vapor explosion (BLEVE) of the remaining liquid. Distillation of hydrogen peroxide at normal pressures is thus highly dangerous.

http://en.wikipedia.org/wiki/Hydrogen_peroxide



http://www.tecaeromex.com/ingles/destilai.htm
hydrogen peroxide distillation and purification machines for producing 90% to 99% pure hydrogen peroxide.

These stills are made entirely of borosilicate glass (PYREX) and Teflon, classified as class 1 for unlimited time exposure with high strength hydrogen peroxide and won’t leave traces of metals or react with the hydrogen peroxide like stills made of stainless steel or aluminum.

This machine distils the hydrogen peroxide at such a low temperature (55ºC - 131ºF) that the hydrogen peroxide doesn't lose any oxygen in the process and the result is a stronger more powerful hydrogen peroxide.

This distillation machine is made using a 20 liter (5.26 gal) flask, in the past we also made a 50 liter (13.15 gal) machine but it was proven that two 20 liter machines produce more hydrogen peroxide than a single 50 liter machine for less money.