April 4, 2006, 0:05 AM CT

Single-molecule Diode May Change Computing

Using the power of modern computing combined with innovative theoretical tools, an international team of scientists has determined how a one-way electrical valve, or diode, made of only a single molecule does its job.

Diodes are critical components within computer, audio equipment and countless other electronic devices. If designers can swap existing diodes with the single-molecule one, the products could be shrunk to incredibly small sizes.

The technology may allow computer designers to sustain "Moore's Law"--a prediction made by Intel co-founder Gordon Moore in 1965--which suggested technological advances will allow a doubling every 18 months in the number of transistors that can fit on a computer chip. But the "law" has been nearing the end of its useful life as ever-shrinking silicon chips approach their physical limits.

Created by a research team at the University of Chicago, the single-molecule diode is merely a few tens of atoms in size and 1,000 times smaller than its conventional counterparts. Recently, theorists from the University of South Florida and the Russian Academy of Sciences have explained the principles that make the device work.

The scientists showed electron energy levels in a molecule are efficient channels for transferring electrons from one electrode to another. Because the molecule in the diode is asymmetrical, the electronic response is also asymmetrical when voltage is applied. The asymmetry contributes to a phenomenon called molecular rectification: the channels conduct electrons in one direction, but limit flow in the opposite direction when the voltage polarity reverses. That property makes the molecular diode a potential gatekeeper for circuits and a candidate to one day replace silicon in computer chips.........

Posted by: Kevin      Permalink         Source

March 30, 2006, 4:29 PM CT

Intense Heat From Gold Nanoparticles

Nanoparticles of gold can act as tiny, precise and powerful heaters, which potentially could be used in biomedical applications, as per a new study.

When stimulated with the right frequency of laser light, a small collection of metal nanoparticles, such as gold, can heat an area up to 1,000 times its size, as per Ohio University researchers Hugh Richardson and Sasha Govorov.

The heating properties were observed in ice, water and a polymer shell that was designed to mimic material in biological systems. Though the ice did not melt when heated by low-intensity laser alone, it dissolved once a gold nanoparticle was embedded, said the scientists, whose findings have been published online by the journal Nano Letters.

The gold particle is 50 nanometers, which is 200,000 times smaller than an object 1 centimeter in size, Govorov said.

The process not only generates a considerable amount of heat at much larger scale than the nanoparticle, but also is very precise, the scientists report. By using bio-linkers, the nanoparticles can be designed to affect specific targets. Bio-linkers are special, sticky molecules that are created to link with only certain types of cells. In a biomedical application, a few gold nanoparticles could be used to generate heat to impact a single macro-scale object, such as a tumor cell.........

Posted by: Kevin      Permalink         Source

March 30, 2006, 4:15 PM CT

Personal Networks In Making

MAGNET is an integrated project supported within the Sixth Framework Programme of the EU Commission. The project acronym stands for "My personal Adaptive Global NET", and as the name indicates the project has a profound emphasis on user-centricity, personalization and personal networking.

The objective of this user-centric approach is to improve the quality of life for the end-user by introducing new technologies more adapted to the user. MAGNET research focuses on environments to become smarter, more responsive, and more accommodating to the needs of the individual without jeopardizing privacy and security. The MAGNET project has a total cost of 18.14 million euro. The EU Commission has granted 10.00 million euro to the project and the remaining 8.14 million comes from partners. The project has a duration of 24 months, and started out January 1st 2004. The project has 37 partners.........

Posted by: Kevin      Permalink         Source

March 29, 2006, 11:16 PM CT

Rising To The Challenge Of Managing Bandwidth

Emerging mobile services are demanding an ever-increasing amount of bandwidth, but the radio spectrum for third generation (3G) and beyond systems is in short supply. Algorithms developed by European researchers are helping operators better manage their precious bandwidth resources.

The EVEREST project developed and tested advanced algorithms to provide mobile operators with enhanced Radio Resource Management (RRM) techniques aimed at reducing the risk of communications bottlenecks at a time when mobile devices are increasingly being used for much more than just voice calls. Email, video conferencing, live television and streaming music, together with a range of other emerging mobile services and applications all increase the pressure on limited network resources.

"Operators will therefore have to manage the scarce resources they have more efficiently if they are to maintain service quality and increase network capacity while meeting consumers' demands for new services," explains Fernando Casadevall, coordinator of this IST project. "The goal is for users to be provided with just the sufficient bandwidth necessary to ensure end-to-end Quality of Service (QoS)".

RRM techniques to control traffic, prioritise some services and clients over others, and switch clients between different wireless communications systems depending on their location and needs are an increasingly necessary feature of network management. Operators benefit by being able to handle more traffic and therefore more clients, while consumers receive better quality services.........

Posted by: Kevin      Permalink         Source

March 29, 2006, 10:03 PM CT

Properties Of Most Popular Conducting Plastic

Steadily increasing the length of a purified conducting polymer vastly improves its ability to conduct electricity, report scientists at Carnegie Mellon University, whose work appeared March 22 in the Journal of the American Chemical Society. Their study of regioregular polythiophenes (RRPs) establishes benchmark properties for these materials that suggest how to optimize their use for a new generation of diverse materials, including solar panels, transistors in radio frequency identification tags, and light-weight, flexible, organic light-emitting displays.

"We found that by growing very pure, single RRP chains made of uniform small units, we dramatically increased the ability of these polymers to conduct electricity," said Richard D. McCullough, who initially discovered RRPs in 1992. "This work establishes basic properties that scientists everywhere need to know to create new, better conducting plastics. In fact, designing materials based on these results could completely revolutionize the printable electronics industry."

"Our results are very significant, since they cast new light on the mechanism by which polymers conduct electricity," said Tomasz Kowalewski, associate professor of chemistry and senior author on the study.

Unlike plastics that insulate, or prevent, the flow of electrical charges, conducting plastics actually facilitate current through their nanostructure. Conducting plastics are the subject of intense research, given that they could offer light-weight, flexible, energy-saving alternatives for materials used in solar panels and screen displays. And because they can be dissolved in solution, affixed to a variety of templates like silicon and manufactured on an industrial scale, RRPs are considered among the most promising conducting plastics in nanotech research today, as per McCullough, dean of the Mellon College of Science and professor of chemistry.........

Posted by: Kevin      Permalink         Source

March 25, 2006, 11:34 AM CT

A Gadget For The Heart

HeartWare is developing a family of implantable mechanical circulatory assist devices or "blood pumps", aimed at treating patients with congestive heart failure. Heart failure is one of the leading causes of death in the developed world, affecting over 10 million people globally.

HeartWare's lead product, the HVAD, is the smallest full-output "third generation" circulatory assist device in development. Having completed extensive pre-clinical studies, the HVAD will begin human clinical trials in early 2006. HeartWare's "next generation" device - the MVAD or Miniaturized VAD - is expected to begin clinical trials in approximately two years. The MVAD is one tenth the size of the HVAD. Small size is a key competitive advantage as it facilitates a relatively fast surgical implantation procedure, enhances patient quality of life, and expands the range of patients who might be implanted with the device.

HeartWare listed on the Australian Stock Exchange (ASX: HTW) on 31 January 2005, raising A$32.4 million (US$24.95 million). The Company's Corporate Head Office is in Sydney, Australia and its Operations Centre is in Miami, USA.........

Posted by: Kevin      Permalink         Source

March 24, 2006, 0:12 AM CT

What Happened to the Antimatter?

Researchers of the DZero collider detector collaboration at the Department of Energy's Fermi National Accelerator Laboratory have announced that their data on the properties of a subatomic particle, the B_s meson ("B sub s"), suggest that the particle oscillates between matter and antimatter in one of nature's fastest rapid-fire processes-more than 17 trillion times per second. Their findings may affect the current view of matter-antimatter asymmetry, and might also offer a first glimpse of the contributions of new physics, such as supersymmetry, to particle physics.

The DZero result, suggesting a preferred oscillation frequency between 17 and 21 times per picosecond (trillionth of a second), is described in a paper submitted to the journal, Physical Review Letters. The result, a measure of the oscillation or "mixing" frequency of the particle, has a confidence level of 90 percent, and so does not qualify as a discovery. Physicists have agreed that claims of a discovery must have a confidence level of 99.99995 percent, indicating a 99.99995 percent chance that the result can be reproduced. The data for the DZero result were culled from one inverse femtobarn of total collision data, or more than one billion events from Fermilab's Tevatron particle accelerator -- a milestone capitalizing on the significant luminosity improvements in the Tevatron. The DZero result also sets the stage for future results. Within the next month or so, the CDF collider detector collaboration at Fermilab expects to have a result with greater precision than the DZero result.........

Posted by: Sarah      Permalink         Source

March 24, 2006, 0:09 AM CT

European Robotics Under The Spotlight

The European Robotic Arm (ERA) will be delivered to Russia this summer in preparation for a launch to the ISS in 2007. ESA and Dutch Space have organised the European Robotics Media Day for 5 April to provide the media with the opportunity to become acquainted with ERA and the engineers behind this ambitious project.

After its launch in November 2007, the 11-metre long robotic arm will perform a variety of tasks outside the ISS. With the ability to move up to 8 tonnes of equipment, ERA will play a key role in the continued construction of the ISS and will be used to move experimental equipment to different external locations. In addition, ERA will be used to move astronauts and cosmonauts around during spacewalks and use its video cameras to carry out inspections of external space station surfaces. ERA therefore has an important role to play in the maintenance and scientific utilisation of the ISS.

These uses of ERA highlight the impact that robotics has on human spaceflight missions. Robotic equipment can be used to undertake certain work in the harsh environment of space that is not suitable or possible to be carried out by astronauts, and also assists astronauts in a range of tasks to help reduce the amount of time needed for spacewalk activities.

Along with the European Columbus laboratory and the Automated Transfer Vehicle (ATV), ERA is one of ESA's main contributions to the ISS. With its seven joints and an impressive concentration of tools and electronics, the robotic arm has the flexibility to move hand-over- hand between fixed base points around the Russian segment of the International Space Station in order to perform its tasks. This flexibility is added to by the fact that ERA can be operated from inside or outside the ISS and can be controlled either in real-time or pre-programmed.........

Posted by: Brooke      Permalink         Source

March 24, 2006, 0:02 AM CT

New Test Of General Relativity?

Researchers funded by the European Space Agency have measured the gravitational equivalent of a magnetic field for the first time in a laboratory. Under certain special conditions the effect is much larger than expected from general relativity and could help physicists to make a significant step towards the long-sought-after quantum theory of gravity.

Just as a moving electrical charge creates a magnetic field, so a moving mass generates a gravitomagnetic field. As per Einstein's Theory of General Relativity, the effect is virtually negligible. However, Martin Tajmar, ARC Seibersdorf Research GmbH, Austria; Clovis de Matos, ESA-HQ, Paris; and his colleagues have measured the effect in a laboratory.

Their experiment involves a ring of superconducting material rotating up to 6 500 times a minute. Superconductors are special materials that lose all electrical resistance at a certain temperature. Spinning superconductors produce a weak magnetic field, the so-called London moment. The new experiment tests a conjecture by Tajmar and de Matos that explains the difference between high-precision mass measurements of Cooper-pairs (the current carriers in superconductors) and their prediction via quantum theory. They have discovered that this anomaly could be explained by the appearance of a gravitomagnetic field in the spinning superconductor (This effect has been named the Gravitomagnetic London Moment by analogy with its magnetic counterpart).........

Posted by: Tyler      Permalink         Source

March 22, 2006, 11:22 PM CT

Space Tool For Clean Drinking Water

As per the UN, safe drinking water remains inaccessible for about 1.1 billion people in the world. To address this global dilemma, the UN Millennium Development pledged at the World Summit in Johannesburg in 2002 to reduce by half the proportion of people without access to safe drinking water by 2015.

Meeting this goal will demand reliable, current data and information about how much water is stored in large lakes, rivers and reservoirs around the world - which radar altimetry can provide.

In the past, hydrological information could often be difficult to obtain by ground-based gauge instruments due to the inaccessibility of the region, the sparse distribution of gauge stations or the slow dissemination of data due to national policy.

Radar altimetry can avoid these obstacles because it is located on satellites 800 to 1300 kilometres above the Earth and is able to measure large lakes' surface water height to two centimetres accuracy and rivers to ten centimetres by sending 1800 separate radar pulses over bodies of water per second and recording how long their echoes take to bounce back. In addition, these data are available in near-real time.

Today there are several teams in the world involved in radar altimetry over inland water, using satellite data from ESA, NASA and the French Space Agency (CNES). Hydrologists from each of these research teams met at the '15 Years of Progress in Radar Altimetry' symposium, organised by ESA and the French Space Agency (CNES) in Venice Lido, Italy, from 13-18 March 2006, to discuss the abilities of past and current altimeters for monitoring the Earth's changing inland water resources.........

Posted by: Tyler      Permalink         Source

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