June 16, 2009, 5:17 AM CT

Magnetic Superatoms

A team of Virginia Commonwealth University researchers has discovered a 'magnetic superatom' - a stable cluster of atoms that can mimic different elements of the periodic table - that one day appears to be used to create molecular electronic devices for the next generation of faster computers with larger memory storage.

The newly discovered cluster, consisting of one vanadium and eight cesium atoms, acts like a tiny magnet that can mimic a single manganese atom in magnetic strength while preferentially allowing electrons of specific spin orientation to flow through the surrounding shell of cesium atoms. The findings appear online in the journal Nature Chemistry.

Through an elaborate series of theoretical studies, Shiv N. Khanna, Ph.D., professor in the VCU Department of Physics, together with VCU postdoctoral associates J. Ulises Reveles, A.C. Reber, and graduate student P. Clayborne, and collaborators at the Naval Research Laboratory in D.C., and the Harish-Chandra Research Institute in Allahabad, India, examined the electronic and magnetic properties of clusters having one vanadium atom surrounded by multiple cesium atoms.

They observed that when the cluster had eight cesium atoms it acquired extra stability due to a filled electronic state. An atom is in a stable configuration when its outermost shell is full. Consequently, when an atom combines with other atoms, it tends to lose or gain valence electrons to acquire a stable configuration......... Posted by: Kevin      Read more         Source

June 5, 2009, 5:00 AM CT

Graphene May Have Advantages Over Copper

The unique properties of thin layers of graphite-known as graphene-make the material attractive for a wide range of potential electronic devices. Scientists have now experimentally demonstrated the potential for another graphene application: replacing copper for interconnects in future generations of integrated circuits.

In a paper reported in the June 2009 issue of the IEEE journal Electron Device Letters, scientists at the Georgia Institute of Technology report detailed analysis of resistivity in graphene nanoribbon interconnects as narrow as 18 nanometers.

The results suggest that graphene could out-perform copper for use as on-chip interconnects-tiny wires that are used to connect transistors and other devices on integrated circuits. Use of graphene for these interconnects could help extend the long run of performance improvements for silicon-based integrated circuit technology.

"As you make copper interconnects narrower and narrower, the resistivity increases as the true nanoscale properties of the material become apparent," said Raghunath Murali, a research engineer in Georgia Tech's Microelectronics Research Center and the School of Electrical and Computer Engineering. "Our experimental demonstration of graphene nanowire interconnects on the scale of 20 nanometers shows that their performance is comparable to even the most optimistic projections for copper interconnects at that scale. Under real-world conditions, our graphene interconnects probably already out-perform copper at this size scale."........ Posted by: Kevin      Read more         Source

June 5, 2009, 4:56 AM CT

Nanoscale zipper cavity

Physicists at the California Institute of Technology (Caltech) have developed a nanoscale device that can be used for force detection, optical communication, and more. The device exploits the mechanical properties of light to create an optomechanical cavity in which interactions between light and motion are greatly strengthened and enhanced. These interactions, notes Oskar Painter, associate professor of applied physics at Caltech, and the principal investigator on the research, are the largest demonstrated to date.

The device and the work that led to it are described in a recent issue of the journal Nature

The fact that photons of light, despite having no mass, nonetheless carry momentum and can interact with mechanical objects is an idea that dates back to Kepler and Newton. The mechanical properties of light are also known to limit the precision with which one can measure an object's position, since simply by using light to do the measurement, you apply a force and disturb the object.

It was important to consider these so-called back-action effects in the design of devices to measure weak, classical forces. Such considerations were part of the development of gravity-wave detectors like the Laser Interferometer Gravitational-Wave Observatory (LIGO). These sorts of interferometer-based detectors have also been used at much smaller scales, in scanning probe instruments used to detect or image atomic surfaces or even single electron spins......... Posted by: Kevin      Read more         Source

June 3, 2009, 5:10 AM CT

Control heat in large data centers

Approximately a third of the electricity consumed by large data centers doesn't power the computer servers that conduct online transactions, serve Web pages or store information. Instead, that electricity must be used for cooling the servers, a demand that continues to increase as computer processing power grows.

And the trend toward cloud computing will expand the need for both servers and cooling.

At the Georgia Institute of Technology, scientists are using a 1,100-square-foot simulated data center to optimize cooling strategies and develop new heat transfer models that can be used by the designers of future facilities and equipment. The goal is to reduce the portion of electricity used to cool data center equipment by as much as 15 percent.

"Computers convert electricity to heat as they operate," said Yogendra Joshi, a professor in Georgia Tech's Woodruff School of Mechanical Engineering. "As they switch on and off, transistors produce heat, and all of that heat must be ultimately transferred to the environment. If you are looking at a few computers, the heat produced is not that much. But data centers generate heat at the rate of tens of megawatts that must be removed".

Summaries of the research have been reported in the Journal of Electronic Packaging and International Journal of Heat and Mass Transfer and presented at the Second International Conference on Thermal Issues in Emerging Technologies, Theory and Applications. The research has been sponsored by the U.S. Office of Naval Research, and by the Consortium for Energy Efficient Thermal Management......... Posted by: Kevin      Read more         Source

June 3, 2009, 5:01 AM CT

Memory with a twist

Electronic memory chips may soon gain the ability to bend and twist as a result of work by engineers at the National Institute of Standards and Technology (NIST). As published in the July 2009 issue of IEEE Electron Device Letters,* the engineers have found a way to build a flexible memory component out of inexpensive, readily available materials.

Though still not ready for the marketplace, the new device is promising not only because of its potential applications in medicine and other fields, but because it also appears to possess the characteristics of a memristor, a fundamentally new component for electronic circuits that industry researchers developed in 2008.** NIST has filed for a patent on the flexible memory device (application #12/341.059).

Electronic components that can flex without breaking are coveted by portable device manufacturers for a number of reasonsand not just because people have a tendency to drop their mp3 players. Small medical sensors that can be worn on the skin to monitor vital signs such as heart rate or blood sugar could benefit patients with conditions that require constant maintenance, for example. Though some flexible components exist, creating flexible memory has been a technical barrier, as per NIST researchers.

Hunting for a solution, the scientists took polymer sheetsthe sort that transparencies for overhead projectors are made fromand experimented with depositing a thin film of titanium dioxide, an ingredient in sunscreen, on their surfaces. Instead of using expensive equipment to deposit the titanium dioxide as is traditionally done, the material was deposited by a sol gel process, which consists of spinning the material in liquid form and letting it set, like making gelatin. By adding electrical contacts, the team created a flexible memory switch that operates on less than 10 volts, maintains its memory when power is lost, and still functions after being flexed more than 4,000 times......... Posted by: Kevin      Read more         Source

June 1, 2009, 6:56 PM CT

Nanosecond pressure jump

A new method to induce protein folding by taking the pressure off of proteins is up to 100 times faster than prior methods, and could help guide more accurate computer simulations for how complex proteins fold, as per research by a team of University of Illinois researchers accepted for publication in the journal Nature Methods and posted on the journal's Web site May 31.

Martin Gruebele, the James R. Eiszner Professor of Chemistry at the U. of I. and corresponding author of the paper, says that prodding proteins to fold by suddenly removing high pressure (a technique also known as "pressure jumping") through electrical bursting makes for a "kindler, gentler way" of inducing proteins to fold.

"When you're increasing the pressure on something, you're squeezing the atoms and making them come closer to one another," Gruebele said, "but you're not necessarily causing the very complicated changes to the microscopic motion that occur when you change the temperature. Pressure is a simpler variable than temperature".

In order to carry out their biomolecular functions, proteins fold from a chaotic, random coil that looks like spaghetti strands floating in boiling water to their native state as an orderly, well-defined but compact structure.

From the point-of-view of the protein, Gruebele said, pressurizing it to about 2,500 atmospheres is much less disruptive than, say, cranking up the temperature by 30 degrees......... Posted by: Kevin      Read more         Source

May 24, 2009, 8:57 PM CT

Multiferroics

Multiferroics are materials in which unique combinations of electric and magnetic properties can simultaneously coexist. They are potential cornerstones in future magnetic data storage and spintronic devices provided a simple and fast way can be found to turn their electric and magnetic properties on and off. In a promising new development, scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) working with a prototypical multiferroic have successfully demonstrated just such a switch -- electric fields.

"Using electric fields, we have been able to create, erase and invert pn junctions in a calcium-doped bismuth ferrite film," said Ramamoorthy Ramesh of Berkeley Lab's Materials Sciences Division (MSD), who led this research.

"Through the combination of electronic conduction with the electric and magnetic properties already present in the multiferroic bismuth ferrite, our demonstration opens the door to merging magnetoelectrics and magnetoelectronics at room temperature".

Ramesh, who is also a professor in the Department of Materials Science and Engineering and the Department of Physics at UC Berkeley, has published a paper on this research that is now available in the on-line edition of the journal Nature Materials The paper is titled: "Electric modulation of conduction in multiferroic......... Posted by: Kevin      Read more         Source

May 18, 2009, 5:38 AM CT

Detecting single atoms

Researchers have devised a new technique for real-time detection of freely moving individual neutral atoms that is more than 99.7% accurate and sensitive enough to discern the arrival of a single atom in less than one-millionth of a second, about 20 times faster than the best prior methods.

The system, described in Advance Online Publication at the Nature Physics web site by scientists at the Joint Quantum Institute (JQI) in College Park, MD, and the Universidad de Concepcin in Chile, employs a novel means of altering the polarization of laser light trapped between two highly-reflective mirrors, in effect letting the researchers "see" atoms passing through by the individual photons that they scatter.

The ability to detect single atoms and molecules is essential to progress in a number of areas, including quantum information research, chemical detection and biochemical analysis.

"Existing protocols have been too slow to detect moving atoms, making it difficult to do something to them before they are gone. Our work relaxes that speed constraint," says coauthor David Norris of JQI. "Moreover, it is hard to distinguish between a genuine detection and a random 'false positive' without collecting data over a large period of time. Our system both filters the signal and reduces the detection time"......... Posted by: Kevin      Read more         Source

May 14, 2009, 9:36 PM CT

Shift in Simulation Superiority

Science and engineering are advancing rapidly in part due to ever more powerful computer simulations, yet the most advanced supercomputers require programming skills that all too few U.S. scientists possess. At the same time, affordable computers and committed national programs outside the U.S. are eroding American competitiveness in number of simulation-driven fields.

These are some of the key findings in the International Evaluation of Research and Development in Simulation-Based Engineering and Science, released on Apr. 22, 2009, by the World Technology Assessment Center (WTEC).

"The startling news was how quickly our assumptions have to change," said Phillip Westmoreland, program director for combustion, fire and plasma systems at the National Science Foundation (NSF) and one of the sponsors of the report. "Because computer chip speeds aren't increasing, hundreds and thousands of chips are being ganged together, each one with a number of processors. New ways of programming are necessary".

Like other WTEC studies, this study was led by a team of leading scientists from a range of simulation science and engineering disciplines and involved site visits to research facilities around the world.

The nearly 400-page, multi-agency report highlights several areas in which the U.S. still maintains a competitive edge, including the development of novel algorithms, but also highlights endeavors that are increasingly driven by efforts in Europe or Asia, such as the creation and simulation of new materials from first principles......... Posted by: Kevin      Read more         Source

May 5, 2009, 5:16 AM CT

Clues for self-cleaning materials

Self-cleaning walls, counter tops, fabrics, even micro-robots that can walk on water -- all those things and more could be closer to reality because of research recently completed by researchers at the University of Nebraska-Lincoln and at Japan's RIKEN institute.

Humans have marveled for millennia at how water beads up and rolls off flowers, caterpillars and some insects, and how insects like water striders are able to walk effortlessly on water. It's a property called super hydrophobia and it's been examined seriously by researchers since at least the 1930s.

"A lot of people study this and engineers particularly like the water strider because it can walk on water," said Xiao Cheng Zeng, Ameritas university professor of chemistry at UNL. "Their legs are super hydrophobic and each leg can hold about 15 times their weight. 'Hydrophobic' means water really doesn't like their legs and that's what keeps them on top. A lot of researchers and engineers want to develop surfaces that mimic this from nature".

In a paper to be reported in the May 4-8 online edition of the Proceedings of the National Academy of Sciences, Zeng and his Japanese colleagues, Takahiro Koishi of the University of Fukui and RIKEN, Kenji Yasuoka of Keio University, and Shigenori Fujikawa and Toshikazu Ebisuzaki of RIKEN, give engineers and materials researchers important clues in how to develop the long-sought super hydrophobic materials......... Posted by: Kevin      Read more         Source

May 5, 2009, 5:14 AM CT

Particles, molecules prefer not to mix

In the world of small things, shape, order and orientation are surprisingly important, as per findings from a newly released study by chemists at Washington University in St. Louis.

Lev Gelb, WUSTL associate professor of chemistry, his graduate student Brian Barnes, and postdoctoral researcher Daniel Siderius, used computer simulations to study a very simple model of molecules on surfaces, which looks a lot like the computer game "Tetris." They have observed that the shapes in this model (and in the game) do many surprising things.

"First, different shapes don't mix very well with each other; each shape prefers to associate with others of the same kind," Gelb says. "When you put a lot of different shapes together, they separate from each other on microscopic scales, forming little clusters of nearly pure fluids. This is true even for the mirror-image shapes.

"Second, the structures of the pure (single-shape) fluids are quite complex and not what we might have predicted. There is a very strong tendency for some of the shapes, like rods and S- and Z- shapes, to align in the same direction. Finally, how `different looking' the shapes are isn't a good predictor for how well they mix; it turns out that the hard-to-predict characteristic structures of the fluids are more important than the shapes themselves, in this regard."........ Posted by: Kevin      Read more         Source

May 4, 2009, 5:16 AM CT

Nanotechnology holds promise

Yale scientists describe a breakthrough in safe and effective administration of potential antiviral drugs small interfering RNA (siRNA) molecules that silence genes the first step in development of a new kind of therapy for sexually transmitted diseases (STDs). The work is reported May 4 as an advance online publication of Nature Materials

"RNA interference is a promising approach for prevention and therapy of human disease," said main author Kim Woodrow, Yale postdoctoral fellow in Yale's School of Engineering & Applied Science. "We wanted to develop a new strategy of delivering siRNAs with a FDA-approved material".

As their name suggests, siRNAs interfere and knock out the function of genes in higher organism as well as in microbes that may cause STDs. The scientists designed siRNAs to target a gene expressed widely in the lining of the female mouse reproductive tract, in this proof-of-principle work.

Using densely-loaded nanoparticles made of a biodegradable polymer known as PLGA, the scientists created a stable "time release" vehicle for delivery of siRNAs to sensitive mucosal tissue like that of the female reproductive system.

They observed that the particles, loaded with the drug agent, moved effectively in two important ways, penetrating to reach cells below the surface of the mucosa and distributing throughout the vaginal, cervical, and uterine regions. Furthermore, the siRNAs stayed in the tissues for at least a week and knockdown of gene activity lasted up to 14 days......... Posted by: Kevin      Read more         Source

April 30, 2009, 5:50 PM CT

SEO Services

Search Engine Optimization is a combined order of practices that yield advanced organic search engine positions. Search engines have become one of the major means through which all web users, like me, trace required information. These days it has become imperative for all kinds of business to make use of these mediums and make themselves more widespread through it. According to my experiences, Nureach Global is aimed at adding something effective and innovative to the Internet Marketing campaign for people who are well aware of this process as well as those who are unversed with it, like me. Their proposals were tailor-made to suit my budget. I appreciate that they understand that each website is unique in its own way and demand a customized proposal. I was immensely impressed when they provided me with a free SEO consultation and analysis. I gained some great results due to their customized proposal. I got higher search engine positions, advanced number of targeted site visitors, sales, and increase in online visibility. They worked on my project and website for continuously six months. It was converted into a high traffic lead producing machine from a mere a business expense. Thanks to Nureach Global, I have achieved a stand above my competitors.

Nureach Global offers through its SEO Services a broad variety of services. These include unlimited e-mail or phone customer support, submission to local & international search engines/directories, current performance & monthly SEO reports, Google (XML)/Yahoo & MSN sitemap creation, Google product search feeds, image & hyperlink optimization, working on html source code, title & Meta tag optimization, manual link requests to related sites, internal link analysis & broken link checker, content writing, and keyword research. These services boosted up my targeted visitors. A large proportion of conversations were converted into deals. TrustRank and Google PageRank of my website were thereby increased. Number of incoming links was multiplied as well. More and more search engines were crawling through and indexing my website with each passing day. I also got higher website rankings for my targeted keywords on search engines like Yahoo, Google, and MSN, and others. The initiative taken by Nureach Global all lead to an increased return-on-investment. I now proudly compete with greater business houses. This has been possible because Search Engine Optimization has exposed my business, products, services, and website to millions of potential customers across the globe. I must confess that this has been one of the wisest choices I have made in promoting my website. I suggest you all adopt the same. I am sure you won't regret you investment......... Posted by: Kevin      Read more         Source

April 27, 2009, 5:21 AM CT

How to catch the lightwave?

New Haven, Conn. As scientists push towards detection of single molecules, single electron spins and the smallest amounts of mass and movement, Yale scientists have demonstrated silicon-based nanocantilevers, smaller than the wavelength of light, that operate on photonic principles eliminating the need for electric transducers and expensive laser setups.

The work reported in an April 26 advance online publication of Nature Nanotechnology ushers in a new generation of tools for ultra-sensitive measurements at the atomic level.

In nanoelectromechanical systems (NEMS), cantilevers are the most fundamental mechanical sensors. These tiny structures fixed at one end and free at the other act like nano-scale diving boards that "bend" when molecules "jump" on them and register a change that can be measured and calibrated. This paper demonstrates how NEMS can be improved by using integrated photonics to sense the cantilever motion.

"The system we developed is the most sensitive available that works at room temperature. Previously this level of sensitivity could only be achieved at extreme low temperatures" said senior author Hong Tang, assistant professor of electrical and mechanical engineering in the Yale School of Engineering and Applied Sciences......... Posted by: Kevin      Read more         Source

April 23, 2009, 5:09 AM CT

Self-healing concrete for safer infrastructure

A concrete material developed at the University of Michigan can heal itself when it cracks. No human intervention is necessary-just water and carbon dioxide.

A handful of drizzly days would be enough to mend a damaged bridge made of the new substance. Self-healing is possible because the material is designed to bend and crack in narrow hairlines rather than break and split in wide gaps, as traditional concrete behaves.

"It's like if you get a small cut on your hand, your body can heal itself. But if you have a large wound, your body needs help. You might need stitches. We've created a material with such tiny crack widths that it takes care of the healing by itself. Even if you overload it, the cracks stay small," said Victor Li, the E. Benjamin Wylie Collegiate Professor of Civil Engineering and a professor of Materials Science and Engineering.

A paper about the material is published online in Cement and Concrete Research. It will be printed in a forthcoming edition of the journal.

In Li's lab, self-healed specimens recovered most if not all of their original strength after scientists subjected them to a 3 percent tensile strain. That means they stretched the specimens to 3 percent beyond their initial size. It's the equivalent of stretching a 100-foot piece an extra three feet-enough strain to severely deform metal or catastrophically fracture traditional concrete......... Posted by: Kevin      Read more         Source

April 22, 2009, 5:23 AM CT

New technique may lead to sharper images

When photographers zoom in on an object to see it better, they lose the wide-angle perspective -- they are forced to trade off "big picture" context for detail. But now an imaging method developed by Princeton scientists could lead to lenses that show all parts of the scene at once in the same high detail. The new method could help build more powerful microscopes and other optical devices.

"It allows you to take a closer look at an object without narrowing your field of view," said Jason Fleischer, an assistant professor of electrical engineering at Princeton who led the research. The study, co-written with graduate students Christopher Barsi and Wenjie Wan, is reported as the cover story in the April edition of Nature Photonics

Cameras and other optical devices -- including the human eye -- are limited by the amount of light that they can collect through their lens openings, or apertures. In order for a light ray to be recorded, it has to pass through the lens and reach the device's "detector" -- such as the eye's retina or a digital camera's detector. But a number of light rays never make it to the detector, either because they are too weak, or because they are deflected.

This problem is especially acute with details that are smaller than the wavelength of light. (Each color of light has a distinct wavelength -- green, for instance, has a wavelength of 530 nanometers, roughly the size of a typical bacterium's internal structure.) Light rays from such tiny features fade before they reach the lens. To capture these rays, devices have to probe very near the surface of the object, and scan it point-by-point, stitching together a full image......... Posted by: Kevin      Read more         Source

Tue, 21 Apr 2009 23:54:32 GMT

Anna Sui for Firefox

(screen capture from www.getpersonas.com/demo_install)

If you are an Anna Sui fan and a Firefox user, you might want to know that you can dress up your browser by downloading "personas" (developed by Mozilla Labs), which include the one you see above by Anna Sui. (There is another one here.) Posted by: PJ      Read more     Source

Tue, 21 Apr 2009 10:28:06 GMT

House of Dereon - Really?

Beyonce gets so much venom spewed at her on blogs that I feel I have to preface this post by stating for the record that I think she is a beautiful and talented young woman. Any negativity in this post is NOT directed at her but more at the design team that brought up this particular ensemble.

When I saw this HoD ad in Lucky magazine, it definitely caught my eye. First, because of the aforementioned loveliness of the model and luminous quality of her skin. Once I soaked that in and really looked at what Bey is wearing, I could not help but marvel at the creation:

A tie-dyed zip up belted peasant-sleeved shoulder revealing granny bloomer jumpsuit with brass button detail at the pockets.

To be fully appreciated, it must be said aloud.

Bey is in the water for this ad but is it swimwear? A pool-side lounging outfit (imagine the tan-lines)?Party wear? Lingerie? I honestly have no idea but it is definitely an eye-catcher.

What do you think? Has House of Dereon made a mark in the fashion world? Posted by: Brigitte      Read more     Source

April 13, 2009, 1:19 PM CT

Laser with controlled polarization

Applied researchers at the Harvard School of Engineering and Applied Sciences (SEAS) in collaboration with scientists from Hamamatsu Photonics in Hamamatsu City, Japan, have demonstrated, for the first time, lasers in which the direction of oscillation of the emitted radiation, known as polarization, can be designed and controlled at will. The innovation opens the door to a wide range of applications in photonics and communications. Harvard University has filed a broad patent on the invention.

Spearheaded by graduate student Nanfang Yu and Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering, both of SEAS, and by a team at Hamamatsu Photonics headed by Dr. Hirofumi Kan, General Manager of the Laser Group, the findings will be published as a cover feature of the April 13 issue of Applied Physics Letters

"Polarization is one of the key features defining a laser beam. Controlling it represents an important new step towards beam engineering of lasers with unprecedented flexibility, tailored for specific applications," explains Capasso. "The novelty of our approach is that instead of being conducted externally, which requires bulky and expensive optical components, manipulation of the beam polarization is achieved by directly integrating the polarizer on the laser facet. This compact solution is applicable to semiconductor lasers and other solid-state lasers, all the way from communication wavelengths to the mid-infrared and Terahertz spectrum".........

Posted by: Kevin      Read more         Source

March 31, 2009, 3:55 PM CT

Mapping the mammalian brain circuits

Thirty-seven researchers from Cold Spring Harbor Laboratory (CSHL) and 20 other major research institutions in the U.S. and Europe have issued a major challenge to the neuroscience community. At long last, the time has come, they argue in a just-published paper, to assemble a comprehensive map of the major neural circuits in the mammalian brain.

In an age in which the genomes of a number of organisms, including that of humans, have been fully sequenced and can be accessed instantly by anyone with a computer, anywhere in the world, it is astonishing to consider that "we have, as yet, not been able to compile a whole-brain map of the circuitry that underlies the functioning of our own brains," notes Professor Partha P. Mitra, Ph.D., senior author of the paper and leader of the ongoing Brain Architecture Project at CSHL, funded by the WM Keck Foundation. To help address this knowledge gap, Mitra organized a series of meetings at the CSHL Banbury Center in 2007 and 2008, from which this proposal grew.

The neuroscience community's "sparse knowledge" of mammalian neuroanatomical circuitry is "perhaps the largest lacuna in our knowledge about nervous system structure," Mitra and his colleagues observe in their paper, which appears in the recent issue of PLoS Computational Biology........ Posted by: Kevin      Read more         Source

March 31, 2009, 2:58 PM CT

3-D printing hits rock-bottom prices

This story is, literally, stone age meets digital age: University of Washington scientists are combining the ancient art of ceramics and the new technology of 3-D printing. Along the way, they are making 3-D printing dramatically cheaper.

About five years ago, Mark Ganter, a UW mechanical engineering professor and longtime practitioner of 3-D printing, became frustrated with the high cost of commercial materials and began experimenting with his own formulas. He and his students gradually developed a home-brew approach, replacing a proprietary mix with artists' ceramic powder blended with sugar and maltodextrin, a nutritional supplement. The results are printed in a recent issue of Ceramics Monthly Co-authors are Duane Storti, UW associate professor of mechanical engineering, and Ben Utela, a former UW doctoral student.

"Normally these supplies cost $30 to $50 a pound. Our materials cost less than a dollar a pound," said Ganter. He said he wants to distribute the free recipes in order to democratize 3-D printing and expand the range of printable objects.

Recipes are available on the magazine's Web site at http://tinyurl.com/d5lcpa.

Glitzy three-dimensional printers have become common in the industrial world, churning out fast 3-D prototypes of everything from airplane parts to running shoes. But the machines also are becoming popular among artists, hobbyists and educational institutions......... Posted by: Kevin      Read more         Source

March 31, 2009, 2:54 PM CT

World's First Nanofluidic Device with Complex 3-D Surfaces

Scientists at the Commerce Department's National Institute of Standards and Technology (NIST) and Cornell University have capitalized on a process for manufacturing integrated circuits at the nanometer (billionth of a meter) level and used it to develop a method for engineering the first-ever nanoscale fluidic (nanofluidic) device with complex three-dimensional surfaces. As described in a paper published online today in the journal Nanotechnology*, the Lilliputian chamber is a prototype for future tools with custom-designed surfaces to manipulate and measure different types of nanoparticles in solution.

Among the potential applications for this technology: the processing of nanomaterials for manufacturing; the separation and measuring of complex nanoparticle mixtures for drug delivery, gene treatment and nanoparticle toxicology; and the isolation and confinement of individual DNA strands for scientific study as they are forced to unwind and elongate (DNA typically coils into a ball-like shape in solution) within the shallowest passages of the device.

Nanofluidic devices are commonly fabricated by etching tiny channels into a glass or silicon wafer with the same lithographic procedures used to manufacture circuit patterns on computer chips. These flat rectangular channels are then topped with a glass cover that is bonded in place. Because of the limitations inherent to conventional nanofabrication processes, almost all nanofluidic devices to date have had simple geometries with only a few depths. This limits their ability to separate mixtures of nanoparticles with different sizes or study the nanoscale behavior of biomolecules (such as DNA) in detail......... Posted by: Kevin      Read more         Source

March 16, 2009, 8:29 PM CT

Spreading high-speed Internet to rural areas

To cut the cost of bringing high-speed Internet to rural areas, Dr. Ka Lun Lee and his colleagues at the University of Melbourne and NEC Australia in the state of Victoria are experimenting with a way to boost the reach of existing technology. Their results, which show a new way to cheaply cover 99 percent of those living in this province, will be presented during the Optical Fiber Communication Conference and Exposition/National Fiber Optic Engineers Conference (OFC/NFOEC), taking place March 22-26 in San Diego.

The 21st century has seen a big push to close the digital divide that separates people in cities from people in rural areas. Even as this divide has closed somewhat in recent years, high-speed Internet is often unavailable, or too costly, for those who live far from the city. As per a 2008 report by the Pew Internet and American Life Research Project, the number of broadband users in rural areas is still about a third less than in urban areas in the United States.

Traditional high-speed services used by city-dwellers -- like DSL or cable -- require extensive networks of equipment and lines out in the field. The cost of this infrastructure increases rapidly as the size of the covered area increases. Other technologies like satellite and fixed wireless offer wider coverage, but are often unreliable and expensive......... Posted by: Kevin      Read more         Source

March 16, 2009, 8:15 PM CT

Magnetic properties of iron-based superconductors

Researchers at the Naval Research Laboratory (NRL) have proposed theoretical models to explain the normal magnetic properties in iron-based superconductors. This research was reported in the December 21, 2008 issue of Nature Physics Their research builds on earlier research they conducted proposing a theoretical model for superconductivity in newly discovered iron-based superconductors. That earlier research was published in Physical Review Letters

To set the stage for the NRL researchers' recent accomplishments, looking back over the last 50 years, the following are three very important discoveries in terms of superconducting materials:

• high-Tc cuprates in 1988, with critical temperature up to 160 K,.
• Magnesium diboride (MgB₂) (2001, 39 K) and.
• iron-based superconductors (2008, up to 57 K).

.

Superconductivity in cuprates (chemical compounds containing copper oxide) is believed to originate from electron-electron interaction, magnetic or Coulomb, and is understood as so-called d-wave symmetry superconductivity. Figure 1 illustrates this concept.

While in conventional BCS superconductors, the superconducting order parameter is the same for all electrons, as illustrated in the first panel (figure 1a), for d-wave (figure 1b) it actually changes sign depending on the direction in which an electron moves (roughly, like cos2α). It is worth noting that in 20 years more than 100,000 papers have been published studying the high-Tc cuprates......... Posted by: Kevin      Read more         Source