April 24, 2006, 7:19 PM CT

Harvesting Daylight And Saving Energy

Researchers at Rensselaer Polytechnic Institute's Lighting Research Center (LRC) have developed a simple, cost-effective, energy-saving device designed to harvest daylight automatically. The DaySwitch was designed as an alternative to traditional dimming ballast systems that adjust light levels by reducing the lamp current.

"The DaySwitch is designed to build end-use efficiency by reducing light energy usage in commercial buildings and maintaining occupant satisfaction," said Peter Morante, director of energy programs at the LRC. "It is estimated that the DaySwitch will be able to reduce lighting energy consumption by 30 percent in buildings with significant daylight contribution through windows or skylights, allowing for a payback period of approximately three years".

Typical dimming systems have several drawbacks, including high initial cost and difficult photosensor programming and installation. As a result, dimming systems have not permeated the market, as per Morante.

The DaySwitch development team, led by Morante and Richard Pysar, an electronic design engineer at the LRC, created a low-cost prototype to control individual light fixtures, unlike traditional systems where one sensor controls numerous lamps. Individual control provides flexibility for on/off control and simple installation.........

Posted by: Kevin      Permalink         Source

April 24, 2006, 7:13 PM CT

New materials for high efficiency organic solid state lighting

A new organic molecule developed by PNNL researchers may significantly improve the efficiency of organic solid state lighting. Direct conversion of electricity to light in "solid state" thin films of organic molecules occurs in organic light emitting devices which can be far more efficient than conventional "incandescent" light bulbs.

In an OLED, light emitting molecules harvest positive and negative charge carriers from oppositely charged electrodes to create excitons, which collapse to give light emission. By using organometallic phosphors, a photon can be emitted for every electron used so there is no wasted current.

But until now, no good host materials were available to transport the charge to blue phosphorescent light emitters. And, without an efficient blue component, it is not possible to generate the high quality white light mandatory for indoor lighting. The PNNL team is solving this problem by linking small organic molecules together using inorganic "phosphine oxide" connecting units to make larger molecules that transport charge but do not interfere with the blue light emission process.........

Posted by: Sarah      Permalink         Source

April 24, 2006, 6:45 AM CT

Next Generation Fuel Cells

The pressure to develop cleaner, more efficient single sources of heat and electrical energy is the driving force behind the development of solid oxide fuel cells (SOFCs) at NRC and elsewhere. However, if SOFCs are to become commercially viable, production costs must be lower and the reliability, as well as durability of these systems needs improvement.

NRC Institute for Chemical Process and Environmental Technology (NRC-ICPET) researchers, Drs. Pamela Whitfield, Gisele Amow and Isobel Davidson, teamed up with Dr. Stephen Skinner (Department of Materials, Imperial College, U.K.) to collaborate on a project that tackled these challenges.

The research was funded by the NRC-British Council Joint S&T Fund and involved comparing methods to synthesize novel cathode materials using a conventional Pechini process and a non-conventional production method - microwave-assisted synthesis. The novel cathode materials produced by both methods were then evaluated for their potential use in intermediate temperature SOFCs.

The two teams worked together on developing new cathode compositions in a family of oxides known to be hyperstoichiometric in oxygen. In this class of materials the ionic transport of oxygen is augmented by interstitial oxide ions within the structure's crystal lattice. Led by Dr. Skinner, the British team provided expertise on measuring oxide ion mobility using a technique of isotopic exchange and secondary ion mass spectroscopy. The research led to new cathode compositions with greater ionic conductivity, thereby decreasing the amount of energy necessary for oxygen ion mobility and enabling the fuel cell to operate at lower temperatures. Lower operating temperatures can increase the durability of SOFCs and makes smaller-scale applications, such as portable power units, more feasible.........

Posted by: Kevin      Permalink         Source

April 22, 2006, 6:01 PM CT

Magnetic Nanotechnology Cancer And Computing

Detecting cancer and reinventing computing are two challenges that seemingly have little, if anything, to do with each other. That is, unless you are a nanotechnologist like Shan Wang, an associate professor of materials science and engineering and of electrical engineering at Stanford. To him, the problems are two sides of the same coin, or more aptly, opposite poles of the same magnet.

"We have known for a long time that magnetism is a fundamental property of all materials and it has found wide applications in electronics and biology, like hard disk drives and magnetic resonance imaging, but there is also great potential to now apply magnetism at the nanoscale," Wang said in an interview in his office at the Geballe Laboratory for Advanced Materials.

There Wang is tuning the characteristics of tiny magnets-on the scale of a billionth of a meter-to help address both cancer and computing. One part of his research group is developing an ultrasensitive detector of DNA and proteins, including proteins associated with cancer. With some of his students, Wang also is making key advances in "spintronics," a new computing technology that could augment or replace silicon microelectronics when progress there is no longer possible because of physical limitations.

Wang's expertise and promising results have made him an important member of two research centers announced this year. On Feb. 27, the National Cancer Institute awarded Stanford $20 million over five years to establish a Center of Cancer Nanotechnology Excellence Wang co-directs with radiology Professor Sanjiv Gambhir. Then on March 9, the university joined with three University of California campuses to announce the Western Institute of Nanoelectronics, a center headquartered at UCLA and dedicated to spintronics research.........

Posted by: Kevin      Permalink         Source

April 20, 2006, 9:29 PM CT

Physicists Get To Heart Of Antimatter

Like Jekyll and Hyde, some subatomic particles are able to act as both matter and their antimatter counterparts. Known as mixing, this process has been known to quantum physicists for 50 years. Now it has been measured for the first time by an international collaboration involving MIT scientists.

The work could lead to a better understanding of the early universe, when these particles were present in great abundance.

The achievement was announced yesterday by Ivan Furic (MIT Ph.D. 2004), now at the University of Chicago, representing the Collider Detector at Fermilab (CDF) collaboration at the Fermi National Accelerator Laboratory.

The CDF team specifically reported rapid-fire transitions between matter and antimatter of a subatomic particle called the Bs (pronounced "B sub s") meson. They found that this particle oscillates between matter and antimatter states at a mind-boggling 3 trillion times per second.

The Bs itself is composed of other subatomic particles: a heavy "bottom quark" bound to a "strange anti-quark".

Christoph Paus, associate professor of physics (and Furic's thesis advisor at MIT), represents MIT in the CDF collaboration, a team of 700 physicists from 61 institutions and 13 countries. Paus, a member of MIT's Laboratory for Nuclear Science, led the data analysis effort involving 80 researchers from 27 institutions.........

Posted by: Sarah      Permalink         Source

April 20, 2006, 0:21 AM CT

Ancient Earthworks Electronically Rebuilt,

Native American cultures that once flourished in Ohio, Kentucky, Indiana and West Virginia constructed geometric and animal-shaped earth works that often rivaled Stonehenge in their astronomical accuracy.

A few are still extant - Serpent Mound in Adams County, Ohio, for example - but most of the region's ancient architecture was all but squandered. Earthworks, from as early as 600 BC that stretched over miles and rose to heights of 15 feet or more, were either gouged out or plowed under in the 19th century or paved over for development in the 20th.

But now, this lost heritage from the Adena, Hopewell and Fort Ancient cultures is returning in the form of a traveling exhibit that will include virtual reconstructions of earthworks from 39 sites. The electronic recreations represent nearly ten years of work by an extensive team of architects, archaeologists, historians, technical experts and Native Americans. Project director is John Hancock, professor of architecture at the University of Cincinnati, working in partnership with the Center for the Reconstruction of Historical and Archaeological Sites (CERHAS) at the University of Cincinnati. The title of the project and the coming traveling exhibit is: "EarthWorks: Virtual Explorations of the Ancient Ohio Valley".........

Posted by: William      Permalink         Source

April 19, 2006, 11:46 PM CT

New Cheaper, More Sophisticated Video-conferencing

If only Fred Astaire and Ginger Rogers were around today to take a spin with new technology being developed and tested by a team of computer researchers in Illinois and California.

If they were, they'd be dancing circles around each other - only from a considerable distance. That's the beauty of Tele-immersive Environments for EVErybody, or TEEVE, a system that's being test-driven simultaneously across thousands of miles this spring in the labs of Klara Nahrstedt, a computer science professor at the University of Illinois at Urbana-Champaign, and Ruzena Bajcsy, a professor of computer science at the University of California at Berkeley.

In technical terms, TEEVE is a distributed multi-tier application that captures images using 3-D camera clusters and distributes them over Internet2 (the network reserved for research and corporate clients), compressing and decompressing the 3-D video streams, rendering them into immersive video and displaying them on one or multiple large screens.

In layman's terms, think of TEEVE as a turbocharged version of videoconferencing, but with some very fancy new bells and whistles. Most notably, Nahrstedt said, TEEVE makes it possible for people to view their counterparts at remote sites from all angles.

And an important feature that sets it apart from other tele-immersive video-conferencing systems currently being developed or used elsewhere is its potential for delivering high-quality images and communications using relatively inexpensive technology and COTS - or commercial-off-the-shelf products and equipment.........

Posted by: Kevin      Permalink         Source

April 18, 2006, 10:44 PM CT

Unbreakable Quantum Encryption

Raw code for "unbreakable" encryption, based on the principles of quantum physics, has been generated at record speed over optical fiber at the Commerce Department's National Institute of Standards and Technology (NIST). The work, reported today at the SPIE Defense & Security Symposium in Orlando, Fla.,* is a step toward using conventional high-speed networks such as broadband Internet and local-area networks to transmit ultra-secure video for applications such as surveillance.

The NIST quantum key distribution (QKD) system uses single photons, the smallest particles of light, in different orientations to produce a continuous binary code, or "key," for encrypting information. The rules of quantum mechanics ensure that anyone intercepting the key is detected, thus providing highly secure key exchange. The laboratory system produced this "raw" key at a rate of more than 4 million bits per second (4 million bps) over 1 kilometer (km) of optical fiber, twice the speed of NIST's prior record, reported just last month.** The system also worked successfully, eventhough more slowly, over 4 km of fiber.

The record speed was achieved with an error rate of only 3.6 percent, considered very low. The next step will be to process the raw key, using NIST-developed methods for correcting errors and increasing privacy, to generate "secret" key at about half the original speed, or about 2 million bps.........

Posted by: Sarah      Permalink         Source

April 18, 2006, 10:37 PM CT

Linking Digital Images To The Cameras That Created The Image

Child pornographers will soon have a harder time escaping prosecution thanks to a stunning new technology in development at Binghamton University, State University of New York, that can reliably link digital images to the camera with which they were taken, in much the same way that tell-tale scratches are used by forensic examiners to link bullets to the gun that fired them.

"The defense in these kind of cases would often be that the images were not taken by this person's camera or that the images are not of real children," said Jessica Fridrich, associate professor of electrical and computer engineering. "Sometimes child pornographers will even cut and paste an image of an adult's head on the image of a child to try to avoid prosecution.

"But if it can be shown that the original images were taken by the person's cell phone or camera, it becomes a much stronger case than if you just have a bunch of digital images that we all know are notoriously easy to manipulate."

Fridrich and two members of her Binghamton University research team - Jan Lukas and Miroslav Goljan - are coinventors of the new technique, which can also be used to detect forged images.

The three have applied for two patents correlation to their technique, which provides the most robust strategy for digital image forgery detection to date, even as it improves significantly on the accuracy of other approaches.........

Posted by: Kevin      Permalink         Source

April 17, 2006, 9:36 PM CT

Unmanned Aerial Vehicles To Track Pollutants

A research consortium funded by the National Science Foundation (NSF) and led by the Scripps Institution of Oceanography at the University of California, San Diego, has successfully sent a fleet of aerial drones through the pollution-filled skies over the Indian Ocean, thereby achieving an important milestone in the tracking of pollutants responsible for dimming Earth's atmosphere.

The instrument-bearing autonomous unmanned aerial vehicles (AUAVs) completed 18 successful data-gathering missions in the vicinity of the Maldives, an island chain nation south of India, said Scripps scientist V. Ramanathan.

During the Maldives AUAV Campaign (MAC), groupings of three aircraft were flown in a vertical formation that allowed their onboard instruments to observe conditions below, inside and above clouds simultaneously. Scientists hope the data produced during the flights will reveal in unprecedented detail how pollution particles cause dimming and contribute to the formation of clouds which amplify the dimming caused by the pollution.

"MAC has demonstrated that lightweight AUAVs and their miniaturized instruments are an effective and inexpensive means of simultaneously sampling clouds in polluted environments from within and from all sides," said Jay Fein, program director in NSF's Division of Atmospheric Sciences, which funded MAC. "They will serve as critically important additions to our atmospheric measurement capability for one of the major issues in climate change science: How does pollution affect cloud microphysical and radiative processes in the context of weather and climate?".........

Posted by: Kevin      Permalink         Source

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