December 18, 2007, 8:11 PM CT

Research could give the Beach Boys a new surfing song

Blacksburg, Va. Surfers in Hawaii had better beware. Four Virginia Tech engineering science and mechanics (ESM) students have completed Surf Green for their senior design project, and conclude that they can technically improve the surfboards performance.

The Beach Boys may have sung about surfing but this team of ESM students decided to quantify the feel of surfing, something only engineers would try to do.

Michael Porter and Stephanie Salmons, both of Virginia Beach, Va., Matthew Dunham of Pleasantville, N.Y., and Nandan Shah of Midlothain, Va., worked with their faculty adviser, Jack Lesko, professor of ESM, for a year, submitting a final report at the end of 2007.

Mike Porter lead the effort and completed most of the work this summer while living out of his van and driving up and down the east coast this summer in search of waves, Lesko smiled. He added that the project lasted beyond the spring semester because the surfboards were in his lab in Norris Hall and inaccessible to the students for weeks after the Virginia Tech tragedy last April.

So, beyond the very good technical work, there is a good bit of character and fortitude exhibited by these students that I would like to acknowledge. I am just honored to be a small part of the lives of these talented students, he added......... Posted by: Kevin      Read more         Source

December 17, 2007, 9:14 PM CT

A 'Gizmo' That Saves Lives

When Javier Rodriguez Molina visited the Atocha Train Station Memorial in Madrid last summer, the Barcelona native felt a great sadness for the victims of the 11 March 2004 Madrid train bombings. But he also felt some hope that his advanced emergency technology work at University of California, San Diego can some day save lives in similar disasters.

Police, firefighters and other emergency workers responding to natural or manmade disasters may someday save more lives with the help of "Gizmo," an advanced mobile wireless communications device.

Rodríguez is Gizmo's lead gadgeteer. He's an electrical engineering graduate student and programmer analyst at UC San Diego's California Institute for Telecommunications and Information Technology (Calit2), one of the most advanced, interdisciplinary research institutes in the world. "Gizmo," which looks like a cross between a remote-controlled toy truck and a lunar landing vehicle, may eventually transform disaster response by collecting and transmitting in real time any information that emergency personnel need via any communications system they're using.

"In almost any emergency, the most important thing is immediate, accurate information," Rodriguez said. "Gizmo will eventually be able to go anywhere on its own and send back in real time whatever information you might need"......... Posted by: Kevin      Read more         Source

December 12, 2007, 10:02 PM CT

Maps Nanomechanical Properties

The National Institute of Standards and Technology (NIST) has developed an imaging system that quickly maps the mechanical properties of materials-how stiff or stretchy they are, for example-at scales on the order of billionths of a meter. The new tool can be a cost-effective way to design and characterize mixed nanoscale materials such as composites or thin-film structures.

The NIST nanomechanical mapper uses custom software and electronics to process data acquired by a conventional atomic force microscope (AFM), transforming the microscope's normal topographical maps of surfaces into precise two-dimensional representations of mechanical properties near the surface. The images enable researchers to see variations in elasticity, adhesion or friction, which may vary in different materials even after they are mixed together. The NIST system, described fully for the first time in a new paper,* can make an image in minutes whereas competing systems might take an entire day.

The images are based on measurements and interpretations of changes in frequency as a vibrating AFM tip scans a surface. Such measurements have usually been made at stationary positions, but until now 2D imaging at a number of points across a sample has been too slow to be practical. The NIST DSP-RTS system (for digital signal processor-based resonance tracking system) has the special feature of locking onto and tracking changes in frequency as the tip moves over a surface. Mechanical properties of a sample are deduced from calculations based on measurements of the vibrational frequencies of the AFM tip in the air and changes in frequency when the tip contacts the material surface......... Posted by: Kevin      Read more         Source

December 12, 2007, 9:50 PM CT

Device Generates and Traps Rare Ultracold Molecules

Physicists at the University of Rochester have combined an atom-chiller with a molecule trap, creating for the first time a device that can generate and trap huge numbers of elusive-yet-valuable ultracold polar molecules.

Researchers believe ultracold polar molecules will allow them to create exotic artificial crystals and stable quantum computers.

"The neat thing about this technology is that it's a very simple, but highly efficient method," says Jan Kleinert, a doctoral physics student at the University of Rochester and designer of the new device. "It lets us produce huge quantities of these ultracold polar molecules, which opens so a number of doors for us".

The Thin WIre electroStatic Trap, or TWIST, is the first electrostatic polar molecule trap that works simultaneously with a magneto-optical atom trap. This means Kleinert can use the lasers of the magneto-optical trap, or MOT, to chill atoms to just a few millionths of a degree above absolute zero, then force the atoms to group into molecules, and instantaneously hold them in place with the electrostatic TWIST trap.

Traditionally, a complex process of creating and trapping is mandatory to produce these molecules, akin to repeatedly emptying and refilling the ice cube trays in your freezer, says Kleinert. A MOT with a TWIST, however, can create and store the chilled molecules in one place, instantly-more like a refrigerator with an automatic icemaker......... Posted by: Sarah      Read more         Source

December 10, 2007, 10:21 PM CT

Sculpted 3-D particles could aid diagnostics

MIT engineers have used ultraviolet light to sculpt three-dimensional microparticles that could have a number of applications in medical diagnostics and tissue engineering. For example, the particles could be designed to act as probes to detect certain molecules, such as DNA, or to release drugs or nutrients.

The new technique offers unprecedented control over the size, shape and texture of the particles. It also allows scientists to design particles with specific chemical properties, such as porosity (a measure of the void space in a material that can affect how fast different molecules can diffuse through the particles).

"With this method, you can rationally design particles, and precisely place chemical properties," said Patrick Doyle, associate professor of chemical engineering. Doyle is one of the authors of a paper on the work appeared in the Dec. 3 issue of the journal Angewandte Chemie, published by the German Chemical Society.

The research team started with a method that Doyle and his students reported in a 2006 issue of Nature Materials to create two-dimensional particles. Called continuous flow lithography, this approach allows shapes to be imprinted onto flowing streams of liquid polymers. Wherever pulses of ultraviolet light strike the flowing stream of small monomeric building blocks, a reaction is set off that forms a solid polymeric particle. They have now modified that method to add three-dimensionality......... Posted by: Kevin      Read more         Source

December 5, 2007, 8:34 PM CT

'Flying Fish' unmanned aircraft takes off

Flying fish were the inspiration for an unmanned seaplane with a 7-foot wingspan developed at the University of Michigan. The autonomous craft is thought to bethe first seaplane that can initiate and perform its own takeoffs and landings on water.

Funded by the Department of Defense's Defense Advanced Research Projects Agency (DARPA), it is designed to advance the agency's "persistent ocean surveillance" program.

Engineering scientists from U-M recently returned from sea trials off the coast of Monterey, Calif., where they demonstrated the craft's capability to DARPA officials.

"The vehicle did very well," said Hans Van Sumeren, associate director of the U-M Marine Hydrodynamics Laboratories. "To take off and land in the water was a big effort. We did it 22 times."

The scientists named the robotic plane Flying Fish after its inspiration. Guy Meadows, director of the U-M Marine Hydrodynamics Laboratories, conceived of the design while out on the water. "I saw these fish pop up and soar over the waves," Meadows said.

That got Meadows and colleagues looking at sea birds for a design for their craft.

"We studied sea birds seriously," Meadows said. "They're all about the same size---about 20 pounds with a 2-meter wingspan. It turns out that, aerodynamically speaking, that's a sweet spot to be flying close to the water. Our plane is about the size of a large pelican."........ Posted by: Kevin      Read more         Source

December 2, 2007, 9:22 PM CT

The best sources of geothermal energy

With fossil fuel sources depleting and global warming on the rise, exploring alternative means of power for humans is a necessary reality. Now, looking to the sky, relying on the wind or harnessing water power are not the only remaining options. Deep within Earth is an untapped source of energy: geothermal energy.

It has been estimated that within the continental United States, there is a sizable resource of accessible geothermal energy about 3,000 times the current annual U.S. consumption.

Two important reasons this storehouse of energy has not been tapped is that locating the specific energy hot spots is difficult and expensive.

Since a number of geothermal resources are hidden, that is, they do not show any clear indications of their presence at the surface, locating them by just using observations made at the surface is difficult, explains Matthijs van Soest, associate research professional at the Noble Gas Geochemistry and Geochronology Laboratory within the School of Earth and Space Exploration at Arizona State University.

Often when people thought there might be a geothermal resource below the surface the only way to determine if their assumption was correct was drilling and drilling is extremely expensive, he says.

Now, research by van Soest and B. Mack Kennedy at Lawrence Berkeley National Laboratory reveals that geothermal exploration doesnt have to be high-priced......... Posted by: Sarah      Read more         Source

December 2, 2007, 9:12 PM CT

Between water and rock

Water chemistry and mineralogy are scientific fields that have been around long enough to develop extensive knowledge and technologies. The boundary of water and rock, however, is not a thin wet line but the huge new field of nanoparticle science.

Researchers are discovering that aquatic nanoparticles, from 1 to 100 nanometers, influence natural and engineered water chemistry and systems differently than similar materials of a larger size. Nanoparticles are in an awkward intermediate state, between elements dissolved in water and minerals that you can hold in your hand, said Michael Hochella Jr., University Distinguished Professor of geosciences at Virginia Tech. The nanoscale represents a transition zone. For instance, the electronic, magnetic, and optical properties at the atomic, nano, and bulk scales are all different.

The cover story of the recent issue of the Royal Society of Chemistrys Journal of Environmental Monitoring (www.rsc.org/Publishing/Journals/em/) offers a critical review of the emerging field of Aquatic environmental nanoparticles. Written by Virginia Tech Ph.D. students Nicholas S. Wigginton of Holt, Mich., and Kelly (Plathe) Haus of Rochester, Minn., and Hochella, the article looks at recent advances in identifying nanoparticles in water and in understanding their properties and reactivity......... Posted by: Sarah      Read more         Source

November 29, 2007, 9:10 PM CT

Helium Isotopes Point to New Sources of Geothermal Energy

Currently, most developed geothermal energy comes from regions of volcanic activity, such as The Geysers in Northern California. The potential resources identified by Kennedy and van Soest arise not from volcanism but from the flow of surface fluids through deep fractures that penetrate the earth's lower crust, in regions far from current or recent volcanic activity. The scientists report their findings in the November 30, 2007 issue of Science.

"A good geothermal energy source has three basic requirements: a high thermal gradient - which means accessible hot rock - plus a rechargeable reservoir fluid, commonly water, and finally, deep permeable pathways for the fluid to circulate through the hot rock," says Kennedy, a staff scientist in Berkeley Lab's Earth Sciences Division. "We believe we have found a way to map and quantify zones of permeability deep in the lower crust that result not from volcanic activity but from tectonic activity, the movement of pieces of the Earth's crust."

Kennedy and van Soest made their discovery by comparing the ratios of helium isotopes in samples gathered from wells, surface springs, and vents across the northern Basin and Range. Helium-three, whose nucleus has just one neutron, is made only in stars, and Earth's mantle retains a high proportion of primordial helium-three (in comparison to the minuscule amount found in air) left over from the formation of the solar system. Earth's crust, conversely, is rich in radioactive elements like uranium and thorium that decay by emitting alpha particles, which are helium-four nuclei. Thus a high ratio of helium-three to helium-four in a fluid sample indicates that much of the fluid came from the mantle......... Posted by: Sarah      Read more         Source

November 27, 2007, 10:21 PM CT

Nanowires may be practical oscillators

Nanowires grown at the National Institute of Standards and Technology (NIST) have a mechanical quality factor at least 10 times higher than reported values for other nanoscale devices such as carbon nanotubes, and comparable to that of commercial quartz crystals. Because a high Q factor indicates a capacity for stable vibrations, the nanowires might be used as oscillators in nano-electromechanical systems for future nano-sensors and communications devices.

We think the most interesting thing about these wires is the very high quality factor observed for such a small object, says NIST researcher and co-author Kris Bertness, who grew the nanowires.

NIST has developed a unique way of growing hexagonal gallium nitride (GaN) nanowires featuring low defect density and high luminescence intensity. In a new paper*, scientists at NIST and the University of Colorado at Boulder report high Q factors in wires that are 30 to 500 nanometers in diameter and 5 to 20 micrometers long, vibrating between 400,000 and 2.8 million times per second. (For comparison, the quartz crystals used in watches commonly vibrate about 32,000 times a second.) The nanowires vibrated when placed on a piezoelectric device stimulated by an electrical signal. The nanowires also oscillated when excited directly by an electron beam, apparently due to the GaN materials intrinsic piezoelectric ability to covert voltage to mechanical force......... Posted by: Kevin      Read more         Source