In a familiar high-school chemistry demonstration, an instructor first uses electricity to split liquid water into its constituent gases, hydrogen and oxygen. Then, by combining the two gases and igniting them with a spark, the instructor changes the gases back into water with a loud pop.
Scientists at the University of Illinois have discovered a new way to make water, and without the pop. Not only can they make water from unlikely starting materials, such as alcohols, their work could also lead to better catalysts and less expensive fuel cells.
“We found that unconventional metal hydrides can be used for a chemical process called oxygen reduction, which is an essential part of the process of making water,” said Zachariah Heiden, doctoral student and lead author of the paper.
Some Texas A&M University researchers examining ancient Egyptian mummies may have unwrapped – literally – some of the mysteries that embalmers used to preserve bodies more than 3,000 years ago.
Mahlon "Chuck" Kennicutt II, MoonKoo Kim and Yaorong Qian of Texas A&M's College of Geosciences, along with colleagues from the University of Alexandria, have discovered that tar originating from natural oil seeps in the Middle East area was used in the preservation and mummification process by Egyptians thousands of years ago.
Examining areas near the Suez Canal, Kennicutt and the team also learned that tar fueled fires in glass factories used by the surrounding communities.
Polymer-based piezoelectric materials are currently the object of great interest in the world of industry because they enable their use in new applications in sectors such as transport and aeronautics, amongst others.
A definition of piezoelectricity – piezo being Greek for “subjected to pressure” - is the generation of the electrical polarisation of a material as a response to mechanical strain.
This phenomenon is known as direct effect or generator effect and is applied fundamentally in the manufacture of sensors (mobile phone vibrators, lighters, etc.). In these cases piezoelectric materials, also used in actuators, undergo an inverse or motor effect, i.e. a mechanical deformation due to the application of an electrical signal.
A Florida State University researcher has helped solve a scientific mystery that stumped chemists for nearly seven decades. In so doing, his team’s findings may lead to the development of more-powerful computer memories and lasers.
Naresh S. Dalal, the Dirac Professor of Chemistry and Biochemistry at FSU, recently collaborated with three colleagues, Jorge Lasave, Sergio Koval and Ricardo Migoni, all of the Universidad Nacional de Rosario in Argentina, to determine why a certain type of crystal known as ammonium dihydrogen phosphate, or ADP, behaves the way it does.
“ADP was discovered in 1938,” Dalal said. “It was observed to have some unusual electrical properties that weren’t fully understood -- and for nearly 70 years, scientists have been perplexed by these properties.
For the first time, scientists have linked the all-too-human preference for a food — chocolate — to a specific, chemical signature that may be programmed into the metabolic system and is detectable by laboratory tests. The signature reads ‘chocolate lover’ in some people and indifference to the popular sweet in others, the researchers say.
The study by Swiss and British scientists breaks new ground in a rapidly emerging field that may eventually classify individuals on the basis of their metabolic type, or metabotype, which can ultimately be used to design healthier diets that are customized to an individual’s needs. The study is scheduled for publication in the Nov.
has just significantly upgraded the capabilities of his molecule rezzer in Second Life. It is available on the Chemistry Corner
on Drexel Island.
300 years after its discovery, the crystal structure of mercury fulminate has been determined.
Though well known by alchemists for its explosive capability and later used as a detonator for dynamite, mercury fulminate's crystal structure has been unknown until now. As Wolfgang Beck, Thomas Klapötke and their team report in the journal ZAAC – Journal of Inorganic and General Chemistry, the orthorhombic crystals consist of separate, nearly linear Hg(CNO)2 molecules.
The alchemists of the seventeenth century were already aware that mixtures of “spiritus vini” (ethanol) and mercury in “aqua fortis” (nitric acid) made for an explosive brew.
Chemists and food scientists at Rutgers employed natural antimicrobial agents derived from sources such as cloves, oregano, thyme and paprika to create novel biodegradable polymers or plastics to potentially block the formation of bacterial biofilms on food surfaces and packaging.
Typically, a variety of bacteria will congregate on a surface to form a bacterial community that exists as a slime-like matrix referred to as a biofilm. This kind of bacterial community is often described as being polymicrobial; it harbors multiple versions of infectious, disease-causing bacteria, such as Salmonella and E. coli.
Most people understand how liquids freeze as solid crystals when temperatures become cold enough, like water droplets crystallizing into snowflakes or molten glass hardening into solid glass.
Latter 20th-century physicists realized that at low enough temperatures, most liquids that exist in nature become energetically unstable as they solidify. Scientists discovered solids that don't have the commonly known, regular crystalline and glass phases - things like liquid crystals, quasi-crystals and charge-density waves. Charge-density waves are systems that display interesting physics, such as metals becoming insulators.
Aircraft engines are more efficient at higher temperatures, but this requires thermal treatment of engine components at very specific high temperatures in excess of 1300 °C. If the heat treatment temperature deviates too much from the optimal temperature, the treatment may be inadequate.
Thermocouples are calibrated using materials with known melting points (fixed points), but the available reference materials in the region of the very high temperatures required to treat jet engine components have a large uncertainty compared with the lower temperature fixed points.
Now measurement scientists at the National Physical Laboratory (NPL) have reduced the uncertainty of thermocouple temperature sensors at high temperatures to within a degree.