September 27, 2007, 9:43 PM CT

Solving A Dragonfly Flight Mystery

Dragonflies adjust their wing motion while hovering to conserve energy, as per a Cornell University study of the insect's flight mechanics. The revelation contradicts prior speculation that the change in wing motion served to enhance vertical lift.

The Cornell physicists came to their conclusions after analyzing high speed images of dragonflies in action. The insects have two pairs of wings, which sometimes move up and down in harmony. At other times the front set of wings flap out of sync with the back set.

The physicists observed that dragonflies maximized their lift, when accelerating or taking off from a perch, by flapping both sets of wings together. When they hover, however, the rear wings flap at the same rate as the front, but with a different phase (imagine two people clapping at the same speed, but with one person's clap delayed relative to the other).

The physicists' analysis of the out-of-sync motion showed that while it didn't help with lift, it minimized the amount of power they had to expend to stay airborne, allowing them to conserve energy while hovering in place.

The research will be detailed in a forthcoming issue of Physical Review Letters. The authors are Z. Jane Wang and David Russell......... Posted by: Ashley      Read more         Source

September 26, 2007, 8:13 PM CT

Recruiting Minorities to Science and Engineering

The Model Institutions for Excellence Program (MIE) funded by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) has developed a body of work over the past 11 years demonstrating successful strategies for recruiting underrepresented minority students to science and engineering fields and supporting their successful completion of science degrees.

Five minority-serving institutions--Bowie State University in Maryland, Spelman College in Atlanta, Universidad Metropolitana in Puerto Rico, the University of Texas at El Paso, and Xavier University of Louisiana in New Orleans--plus the Oyate Consortium, representing three tribal colleges in the Midwest, are MIE's participating institutions.

Their collective results show that underrepresented minority students' enrolling in science, technology, engineering and mathematics (STEM) coursework increased at a higher rate than total STEM enrollment. Meanwhile, the total number of bachelor's STEM degrees conferred increased by 44 percent, from 691 in the 1994-1995 academic year to 994 in 2004-2005.

These results are noteworthy in light of the fact that over nearly 40 years, the percentage of bachelor's degrees awarded in science and engineering (out of all fields of study) has remained static at about 32-35 percent. MIE helps address a national concern about maintaining a pipeline of trained researchers that are needed to make the discoveries that will spark innovations in national security, healthcare and industry--supporting the quality of life of all citizens......... Posted by: Tom      Read more         Source

September 21, 2007, 5:22 AM CT

Computer program traces ancestry

A group of computer scientists, mathematicians, and biologists from around the world have developed a computer algorithm that can help trace the genetic ancestry of thousands of individuals in minutes, without any previous knowledge of their background. The teams findings would be reported in the September 2007 edition of the journal PLoS Genetics.

Unlike prior computer programs of its kind that require previous knowledge of an individuals ancestry and background, this new algorithm looks for specific DNA markers known as single nucleotide polymorphisms, or SNPs (pronounced snips), and needs nothing more than a DNA sample in the form of a simple cheek swab. The scientists used genetic data from prior studies to perform and confirm their research, including the new HapMap database, which is working to uncover and map variations in the human genome.

Now that we have observed that the program works well, we hope to implement it on a much larger scale, using hundreds of thousands of SNPs and thousands of individuals, said Petros Drineas, the senior author of the study and assistant professor of computer science at Rensselaer Polytechnic Institute. The program will be a valuable tool for understanding our genetic ancestry and targeting drugs and other medical therapys because it might be possible that these can affect people of different ancestry in very different ways......... Posted by: Kevin      Read more         Source

September 12, 2007, 6:54 PM CT

Lighter gas reduces damage to optics

Scientists at the University of Illinois have discovered a way to generate light and reduce damage in a leading candidate for next-generation microelectronics lithography. The technique could help pack more power into smaller computer chips.

In the quest for creating computer chips with ever-smaller feature sizes, chip manufacturers are exploring extreme ultraviolet lithography as the next chip-printing technology. For a light source at the necessary wavelength, researchers have turned to a hot, ionized gas called a plasma, generated within a Z-pinch device. But, energetic ions produced in the plasma can damage the mirror responsible for collecting the light.

"By adding a lighter gas to the plasma, we can significantly reduce the damage and extend the lifetime of the collector optics," said David Ruzic, a professor of nuclear, plasma and radiological engineering and lead author of a paper that describes the technique in the recent issue of the journal IEEE Transactions on Plasma Science.

In a Z-pinch device, xenon is fed into a chamber where it collides with a stream of electrons, producing a low-temperature and low-density plasma. This plasma then flows between two cylindrical electrodes, one positioned inside the other. (The "Z" in Z-pinch refers to the direction of current flow along the cylindrical electrodes.)......... Posted by: Kevin      Read more         Source

September 10, 2007, 9:46 PM CT

Nanoscale Features the Easy Way

Researchers at the Georgia Institute of Technology have developed a new technique for nanolithography that is extremely fast and capable of being used in a range of environments including air (outside a vacuum) and liquids. Scientists have demonstrated the technique, known as thermochemical nanolithography, as a proof of concept. The technique may allow industry to produce a variety of nanopatterned structures, including nanocircuits, at a speed and scale that could make their manufacture commercially viable. The research, which has potential applications for fields ranging from the electronics industry to nanofluidics to medicine, appeared earlier this year in the journal Nano Letters.

The technique is surprisingly simple. Using an atomic force microscope (AFM), scientists heat a silicon tip and run it over a thin polymer film. The heat from the tip induces a chemical reaction at the surface of the film. This reaction changes the film's chemical reactivity and transforms it from a hydrophobic substance to a hydrophilic one that can stick to other molecules. The technique is extremely fast and can write at speeds faster than millimeters per second. That's orders of magnitude faster than the widely used dip-pen nanolithography (DPN), which routinely clocks at a speed of 0.0001 millimeters per second......... Posted by: Kevin      Read more         Source

Thu, 06 Sep 2007 01:34:46 GMT

Flight Simulator hidden in Google Earth

Google Earth, the program you install on your computer to explore the earth, has a nice little "easter egg" built in : A fully working flightsimulator. The game was first discovered by a blogger from South Africa, who immediately revealed the game on his blog.
Just as he says on his blog, Google is wellknown for releasing data without ever saying a word about it. Apparently he was unable to find anything about the hidden game in Google Earth.It's not in the release notes and a search on Google produces no results. Seems Google have done one of their unpublicised updates they're becoming well-known for.
The game exists only in the latest version of Google Earth. On a mac, press control+a to start the game. On windows you can start it by typing Ctrl+Alt+A.

I wonder what else Google has hidden in unexpected places..... Posted by: S.M. Schrama      Read more     Source

September 4, 2007, 6:56 PM CT

Computer Scientists Take the Why out of WiFi

People expect WiFi to work, but there is also a general understanding that it's just kind of flakey," said Stefan Savage, one of the UCSD computer science professors who led development of an automated, enterprise-scale WiFi troubleshooting system for UCSD's computer science building. The system is described in a paper presented last week in Kyoto, Japan at ACM SIGCOMM, one of the world's premier networking conferences.

"If you have a wireless problem in our building, our system automatically analyzes the behavior of your connection - each wireless protocol, each wired network service and the a number of interactions between them. In the end, we can say 'it's because of this that your wireless is slow or has stopped working' - and we can tell you immediately," said Savage.

For humans, diagnosing problems in the now ubiquitous 802.11-based wireless access networks requires a huge amount of data, expertise and time. In addition to the myriad complexities of the wired network, wireless networks face the additional challenges of shared spectrum, user mobility and authentication management. Finally, the interaction between wired and wireless networks is itself a source of a number of problems.

"Wireless networks are hooked on to the wired part of the Internet with a bunch of 'Scotch tape and bailing wire' - protocols that really weren't designed for WiFi," explained Savage. "If one of these components has a glitch, you may not be able to use the Internet even though the network itself is working fine."........ Posted by: Kevin      Read more         Source

September 3, 2007, 11:27 AM CT

Low-cost Recipe For Patterning Microchips

Creating ultrasmall grooves on microchips -- a key part of a number of modern technologies -- is about to become as easy as making a sandwich, using a new process invented by Princeton engineers.

The simple, low-cost technique results in the self-formation of periodic lines, or gratings, separated by as few as 60 nanometers -- less than one ten-thousandth of a millimeter -- on microchips. Features of this size have a number of uses in optical, biological and electronic devices, including the alignment of liquid crystals in displays. The scientists will publish their findings Sept. 2 in the online version of Nature Nanotechnology.

Its like magic, said electrical engineer Stephen Chou, the Joseph C. Elgin Professor of Engineering. This is a fundamentally different way of making nanopatterns.

The process, called fracture-induced structuring, is as easy as one-two-three. First, a thin polymer film is painted onto a rigid plate, such as a silicon wafer. Then, a second plate is placed on top, creating a polymer sandwich that is heated to ensure adhesion. Finally, the two plates are pried apart. As the film fractures, it automatically breaks into two complementary sets of nanoscale gratings, one on each plate. The distance between the lines, called the period, is four times the film thickness......... Posted by: Kevin      Read more         Source

August 28, 2007, 9:37 PM CT

simpler method for analyzing radium in water

A simpler technique for testing public drinking water samples for the presence of the radioactive element radium can dramatically reduce the amount of time required to conduct the sampling required by federal regulations. The U.S. Environmental Protection Agency (EPA) has approved use of the new testing method.

The technique developed by Bernd Kahn, director of the Georgia Tech Research Institutes (GTRI) Environmental Radiation Center (ERC), and GTRI senior research scientist Robert Rosson became advantageous when the EPA established new radionuclide drinking water standards in 2000.

While radium is found at low concentrations in soil, water, plants and food, the greatest potential for human exposure to radium is through drinking water. Research shows that inhalation, injection, ingestion or body exposure to relatively large amounts of radium can cause cancer and other disorders. Since radium is chemically similar to calcium, it has the potential to cause harm by replacing calcium in bones.

As a result, drinking water systems are now required to sample and report on the amounts of two isotopes, radium-226 and radium-228, that are sometimes found in drinking water supplies.

The Georgia Department of Natural Resources recognized the applicability and benefits of our method because of the new rules and proposed it to the EPA in 2002, said Kahn......... Posted by: Kevin      Read more         Source

August 26, 2007, 10:55 AM CT

Toxic Byproducts of Carbon Nanotube Manufacturing

A new analysis of by-products discharged to the environment during production of carbon nanotubes (CNTs) -- expected to become the basis of multibillion-dollar industries in the 21st Century -- has identified cancer-causing compounds, air pollutants, and other substances of concern, scientists reported here today at the 234th national meeting of the American Chemical Society.

Co-author of study Desiree L. Plata and his colleagues described their work as "totally new," noting that past analyses of the environmental impact of the emerging nanomaterials industry have been based on the toxicity of ingredients used in the recipes, rather than the actual pollutants formed during CNT manufacture. While expressing concern about the possible health and environmental effects of nanotechnology by-products, Plata said the new data may be crucial as the nanotechnology industry seeks to avoid the kind of unanticipated health and environmental problems that have accompanied emergence of other new technology.

Scientists said, for instance, that they foresee developing, in collaboration with the CNT industry, "green chemical" reactions and filtration systems to substitute for those with potentially hazardous by-products and other ways of manufacturing carbon nanotubes that minimize potentially adverse impacts......... Posted by: Kevin      Read more         Source