August 26, 2007, 10:37 AM CT

Basalt In The Outer Asteroid Belt

Analysis of the chemical make up of two asteroids in the outer asteroid belt has thrown the classification system for these small bodies, which orbit between Mars and Jupiter, into disorder.

Dr Rene Duffard, who is presenting results at the European Planetary Science Congress in Potsdam on Wednesday 22nd August, said, "We appear to have detected basalt on the surface of these asteroids, which is very unusual for this part of the asteroid belt. We do not know whether we have discovered two basaltic asteroids with a very particular and previously unseen mineralogical composition or two objects of non basaltic nature that have to be included in a totally new taxonomic class".

The presence of basalt means that the asteroid must have melted partially at some time in the past, which implies that it was once part of a larger body which had internal heating processes. However, there do not appear to be other basaltic fragments in the region and, from spectral analysis, it is not clear whether the two are fragments of the same parent body or not.

Until recently, most of the known basaltic asteroids, which are classified as V-type, were believed to be fragments of Vesta, the second largest object in the asteroid belt. Since 2001, several V-type asteroids have been identified as not belonging to this Vesta family, including (1459) Magnya, the first basaltic object to be detected in the outer asteroid belt......... Posted by: Brooke      Read more         Source

August 25, 2007, 7:18 AM CT

Highly sensitive weather radar

TU Delft has taken a new weather radar system into use, the 'Drizzle Radar', which can observe even the lightest of drizzles. This is an enormous gain for climate scientists and is attracting international attention. The radar was successfully installed on the 213 metre-high Royal Netherlands Meteorological Institute (KNMI) measurement tower in Cabauw, near Lopik, on Thursday, August 23. From this spot the highly sensitive radar, together with the other advanced instruments of the CESAR observatory (Cabauw Experimental Site for Atmospheric Research), is to provide a complete picture of the interaction between dust, clouds, rain and radiation. The latter is still one of the least understood factors in climate models.

Clouds and the climate

Clouds are of great importance for the greenhouse effect. On the one hand, clouds wrap a blanket round the Earth which retains heat, but they also cool the planet through the reflection of sunlight. Clouds can therefore compensate for some of the global warming, but the question is how much, and how precisely does it work. Dust particles play a crucial role in the formation of clouds and precipitation. They act as condensation nuclei, around which small droplets form. The more dust particles, the more dense the clouds, the more solar radiation is reflected and the cooler the Earth stays......... Posted by: Kevin      Read more         Source

August 25, 2007, 7:16 AM CT

Explosive crystal

Known to the alchemists and long used as a detonator to set off dynamite-mercury fulminate has a checkered past. Now, more than 300 years after the discovery of this explosive compound, German scientists have been able to characterize its crystal structure and thus finally reveal the molecular structure of mercury fulminate. As Wolfgang Beck, Thomas Klapotke 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. In his book Laboratorium Chymicum, Johann Kunckel von Lowenstern describes the vigorous reaction of mercury nitrate with alcohol to form mercury fulminate (Hg(CNO)2). In 1799, the English chemist Edward Howard isolated the compound by chance, which was produced a sensation in the nascent scientific field of chemistry.

Mercury fulminate is very sensitive to shock, friction, and sparks. It explosively decomposes to form mercury, carbon monoxide, and nitrogen. This explosive power was used extensively: Alfred Nobel put mercury fulminate into blasting caps for detonating dynamite. This relatively safe new detonator was what allowed for the huge success of dynamite. In Gera number of alone, the annual production of mercury fulminate in the early 20th century reached about 100,000 Kg......... Posted by: Sarah      Read more         Source

August 23, 2007, 10:28 PM CT

Ground-breaking antilandmine radar

Scientists in The Netherlands are in the process of developing a radar system that might one day see through solid earth and could be used to clear conflict zones of landmines, safely and at low cost. Writing in Inderscience's Journal of Design Research, the team explains how the new technology, with further industrial development, could eventually make vast tracts of land around the globe safe once more.

Landmines were first used widely during World War II and continue to represent a significant threat to life and limb in areas afflicted by war. Originally, landmines were used to protect strategic areas such as borders, camps or important bridges and to restrict the movement of enemy forces. The use of landmines has spread to countless national conflicts and they are now usually used by terrorist and other organizations against civilians and rivals. This has led to a major proliferation of landmines in a number of areas beyond conventional military conflict zones.

In the absence of records, the low cost of landmines and the vast areas that have been polluted with them due to aerial distribution, clearing landmines has become and increasingly frustrating and hazardous task.

A single landmine might cost $1, but once in the ground locating it and making it safe can cost up to $1000. As per P. van Genderen and A.G. Yarovoy in the Faculty of Electrical Engineering at Delft University of Technology, this cost is prohibitive in most areas affected by landmine use and so a cheaper solution is needed. The scientists also point out that a detection system that does not distinguish between landmines and other buried objects is not viable......... Posted by: Kevin      Read more         Source

August 21, 2007, 6:26 PM CT

Hydrogen For Tomorrow's Vehicles

Hydrogen may prove to be the fuel of the future in powering the effi cient, eco-friendly fuel cell vehicles of tomorrow. Developing a method to safely store, dispense and easily "refuel" the vehicle's storage material with hydrogen has baffl ed scientists for years. However, a new and attractive storage medium being developed by Pacific Northwest National Laboratory researchers may provide the "power of pellets" to fuel future transportation needs.

The Department of Energy's Chemical Hydrogen Storage Center of Excellence is investigating a hydrogen storage medium that holds promise in meeting long-term targets for transportation use. As part of the center, PNNL researchers are using solid ammonia borane, or AB, compressed into small pellets to serve as a hydrogen storage material. Each milliliter of AB weighs about three-quarters of a gram and harbors up to 1.8 liters of hydrogen. Scientists expect that a fuel system using small AB pellets will occupy less space and be lighter in weight than systems using pressurized hydrogen gas, thus enabling fuel cell vehicles to have room, range and performance comparable to today's automobiles.

"With this new understanding and our improved methods in working with ammonia borane," said PNNL scientist Dave Heldebrant, "we're making positive strides in developing a viable storage medium to provide reliable, environmentally friendly hydrogen power generation for future transportation needs"......... Posted by: Sarah      Read more         Source

August 21, 2007, 6:20 PM CT

molecules in living cells

Clemson University chemists have developed a method to dramatically improve the longevity of fluorescent nanoparticles that may someday help scientists track the motion of a single molecule as it travels through a living cell.

The chemists are exploiting a process called resonance energy transfer, which occurs when fluorescent dye molecules are added to the nanoparticles. Their findings will be reported at the 234th annual national American Chemical Society meeting Aug.19-24 in Boston.

If researchers could track the motion of a single molecule within a living cell it could reveal a world of information. Among other things, researchers could determine how viruses invade a cell or how proteins operate in the body. Such technology also could help doctors pinpoint the exact location of cancer cells in order to better focus therapy and minimize damage to healthy tissue. Outside the body, the technology could help speed up detection of such toxins as anthrax.

The key to developing single-molecule tracking technology may be the development of better fluorescent nanoparticles.

Fluorescent nanoparticles are thousands of times smaller than the width of a human hair and are similar in size to protein molecules, to which they can be attached. When illuminated by a laser beam inside a light microscope equipped with a sensitive digital camera, the nanoparticle attached to a protein will light up, allowing researchers to get a precise fix on the position of the protein and monitor its motion inside a cell......... Posted by: Kevin      Read more         Source

August 21, 2007, 5:49 PM CT

Hurricane Dean tracked from space

ESA satellites are tracking the path of Hurricane Dean as it rips across the Caribbean Sea carrying winds as high as 260 km/h. The hurricane, which has already claimed eight lives, is forecast to slam into Mexico's Yucatan Peninsula on Tuesday morning.

Dean was upgraded early Tuesday to a Category 5 - the highest on the Saffir-Simpson scale - before pummelling the peninsula. Knowing the strength and path of hurricanes is critical for issuing timely warnings; satellites are the best means of providing data on the forces that power the storm, such as cloud structure, wind and wave fields, sea surface temperature and sea surface height.

Instruments aboard ESA's Envisat and ERS-2 satellites allow them to peer through hurricanes. Envisat carries both optical and radar instruments, enabling scientists to observe high-atmosphere cloud structure and pressure in the visible and infrared spectrum.

The Medium Resolution Imaging Spectrometer (MERIS) optical instrument shows the swirling cloud-tops of a hurricane, while radar instruments such as the Advanced Synthetic Aperture Radar (ASAR) pierce through the clouds to show how the wind fields shape the sea surface and estimate their likely destructive extent.

ERS-2 uses its radar scatterometer to observe the hurricane's underlying wind fields. The scatterometer instrument works by firing a trio of high-frequency radar beams down to the ocean, then analysing the pattern of backscatter reflected up again. Wind-driven ripples on the ocean surface modify the radar backscatter, and as the energy in these ripples increases with wind velocity, backscatter increases as well. Scatterometer results enable measurements not only of wind speed but also of direction across the water surface......... Posted by: Brooke      Read more         Source

August 21, 2007, 5:29 PM CT

More Cheaper Hydrogen

A new class of catalysts created at the U.S. Department of Energy's Argonne National Laboratory may help researchers and engineers overcome some of the hurdles that have inhibited the production of hydrogen for use in fuel cells.

Argonne chemist Michael Krumpelt and colleagues in Argonne's Chemical Engineering Division used "single-site" catalysts based on ceria or lanthanum chromite doped with either platinum or ruthenium to boost hydrogen production at lower temperatures during reforming. "We've made significant progress in bringing the rate of reaction to where applications require it to be," Krumpelt said.

Most hydrogen produced industrially is created through steam reforming. In this process, a nickel-based catalyst is used to react natural gas with steam to produce pure hydrogen and carbon dioxide.

These nickel catalysts typically consist of metal grains tens of thousands of atoms in diameter that speckle the surface of metal oxide substrates. On the other hand, the new catalysts that Krumpelt developed consist of single atomic sites imbedded in an oxide matrix. The difference is akin to that between a yard strewn with several large snowballs and one covered by a dusting of flakes. Because some reforming processes tend to clog much of the larger catalysts with carbon or sulfur byproducts, smaller catalysts process the fuel much more efficiently and can produce more hydrogen at lower temperatures......... Posted by: Sarah      Read more         Source

August 21, 2007, 5:27 PM CT

Volcano Safety For Ecuadorians

A geologist at Washington University in St. Louis is doing his part to make sure that the small Latin American country of Ecuador follows the Boy Scout motto: Be prepared.

Robert Buchwaldt, Ph.D., Washington University lecturer in earth and planetary sciences in Arts & Sciences, is the only scientist from America who sits on an international committee that is seeking ways to address the volcanic threat in Ecuador, particularly in Quito, a city of five million nestled against a volcano, Guagua Pichincha, that erupted just two years ago.

Buchwaldt, a couple of German researchers and a mixture of Ecuadorian politicians and citizens comprise the committee, which is called the Ecuadorian Volcanic Hazard Assessment Group. Its task is to develop an emergency plan in case of an eruption, which could happen again soon because magma temperatures are rising, as per Buchwaldt.

"Dealing with the threat of a volcano is not an uncommon problem," Buchwaldt said. "In North America, we have Seattle, which is adjacent to Mount St. Helens and two other volcanoes. They have a plan. We're trying to implement one in Quito, but the Latin American culture is different."

Money and communications problems.

A key problem is wealth, or the lack thereof, in Ecuador......... Posted by: Tyler      Read more         Source

August 21, 2007, 5:21 PM CT

e-Science points to pollution solutions

Results from a UK e-Science project are helping to solve two pressing environmental problems. One finding could help to avoid arsenic contamination of drinking water extracted from man-made wells. Another could lead to improved methods of removing the now-banned industrial chemical, dioxin, from soil. The results were obtained using e-Science techniques and grid computing to simulate all the possible interactions between these contaminants and rock or soil.

Arsenic often appears in minerals rich in iron and sulphur, such as pyrite (fools gold). Researchers working as part of eMinerals, a major project funded under the Natural Environment Research Councils e-Science programme, have found out precisely how arsenic is taken up and held in the pyrite structure and the factors likely to lead to its release. We now know that arsenic replaces the sulphur in pyrite rather than the iron, and that pyrite is likely to dissolve more easily when arsenic is present, says Dr Kate Wright, who worked on the project. Further work could identify ways of stabilising arsenic-containing iron sulphide rock by introducing additives that slow the rate at which it dissolves.

The eMinerals project observed that a dioxin molecule will bind more strongly to clay surfaces the more chlorine atoms it contains, irrespective of the position of the chlorine atoms in the dioxin molecule. It also observed that binding is stronger the greater the electrical charge on the surface. However, water competes with dioxin to bind to surfaces and, in practice, a dioxin molecules ability to bind to a surface is a balance between the binding strength of the dioxin to the surface, the water to the surface, and the dioxin to the water......... Posted by: Kevin      Read more         Source