October 10, 2007, 7:15 PM CT

Physics professor probes superconductivity

When Eric Hudson was introduced to high-temperature superconductivity as a graduate student, it was still, so to speak, a hot topic.

The phenomenon, discovered in the 1980s, reflects the fact that if you develop the right types of compounds, you can create electrical conductors that are completely resistance-free at temperatures well above the threshold for conventional superconductors.

"With conventional systems, you get to about 25 degrees Kelvin [-415? F] and then plateau," says Hudson, now the Class of 1958 Assistant Professor of Physics at MIT. "With high-temperature superconductivity, you were suddenly at 90 degrees Kelvin".

That figure is well above the mark at which nitrogen gas turns liquid. This meant you could create devices like the high-powered electromagnets used in a number of MRI scanners without having to use costly liquid helium to cool the magnets' coils to superconducting temperatures. (Helium, which liquefies at a hyper-frigid 4 degrees above absolute zero, is a must for conventional superconducting devices.).

More exciting yet, the discovery seemed to signal that room-temperature superconductivity was on its way. This triggered claims that problems like electricity line -losses--the often-hefty amount of power lost to resistance in electrical transmission networks--would soon -disappear......... Posted by: Kevin      Read more         Source

October 10, 2007, 7:07 PM CT

Increase in ethanol production from corn

If projected increases in the use of corn for ethanol production occur, the harm to water quality could be considerable, and water supply problems at the regional and local levels could also arise, says a new report from the National Research Council. The committee that wrote the report examined policy options and identified opportunities for new agricultural techniques and technologies to help minimize effects of biofuel production on water resources.

Recent increases in oil prices in conjunction with subsidy policies have led to a dramatic expansion in corn ethanol production and high interest in further expansion over the next decade, says the report. Indeed, because of strong national interest in greater energy independence, in this year's State of the Union address, President Bush called for the production of 35 billion gallons of ethanol by 2017, which would equal about 15 percent of the U.S. liquid transportation fuels.

A National Research Council committee was convened to look at how shifts in the nation's agriculture to include more energy crops, and potentially more crops overall, could affect water management and long-term sustainability of biofuel production. Based on findings presented at a July colloquium, the committee came to several conclusions about biofuel production and identified options for addressing them......... Posted by: Kevin      Read more         Source

October 10, 2007, 5:54 PM CT

Simultaneous Study of Multiple Variables

Researchers at the U.S. Department of Energy's Brookhaven National Laboratory have developed a method for correlating the results of microscopic imaging techniques in a way that could lead to improved understanding, diagnosis, and possibly therapy of a variety of disease conditions, including Alzheimer's disease. The Laboratory has filed a U.S. provisional patent application for the invention.

The invention is essentially a micron-scale metallic marking grid upon which researchers place their samples - biological tissues or inorganic samples such as minerals - previous to imaging with different methods. "When the findings are analyzed, the grid can be used to 'map,' or orient, the images to one another, allowing us to study multiple variables in a single sample and better understand how they relate to one another," said biophysicist Lisa Miller, leader of the team that developed the new method.

Typically for example, a number of diseases such as alzheimer's are characterized by changes in both organic materials, such as proteins, as well as changes in the composition or concentration of inorganic trace metals (e.g., iron, copper, and zinc). Researchers have techniques - infrared spectroscopy and x-ray fluorescence - for studying each of these independently. But without a way to correlate the findings from the two methods, important information about the relationship between the organic and inorganic components can be missed......... Posted by: Kevin      Read more         Source

October 10, 2007, 5:17 PM CT

Biometric sensors no dirtier than doorknobs

While biometric equipment is gaining popularity in a variety of applications, such as ensuring secure access to buildings, industries are finding that a number of users believe the devices are unsanitary and a potential source of germs that could cause illness.

But a Purdue University study has observed that while the platen glass surfaces of devices that scan fingerprints or hand geometry may look more unsanitary due to visible dirt and prints, they in fact harbor about the same amount of bacteria as a typical doorknob.

Christine R. Blomeke, a researcher and doctoral student in Purdue's Biometric Standards, Performance and Assurance Laboratory, performed the study along with lab director Stephen J. Elliott, an associate professor of industrial technology, and Thomas M. Walter, a continuing lecturer in the Department of Biological Sciences.

Blomeke said the study was conducted because of participant comments made during fingerprint and hand-geometry studies at the lab. She said the subjects, who were mandatory to touch their hands or fingers to the sensors, questioned the cleanliness of the surfaces.

"When you look at these devices, finger moisture, dirt and oils cause the surface to appear to be dirty," Blomeke said. "In a study we did on this last year, more than a quarter of the participants indicated that they thought the devices were somewhat unsanitary......... Posted by: Kevin      Read more         Source

October 8, 2007, 8:53 AM CT

'Green' leather is in this season

Fashionistas after the latest in leather bags could soon have a greener selection to choose from. Researchers in India have modified the tanning process making it far more eco-friendly, reports Anne Pichon in Chemistry & Industry, the magazine of the SCI.

Tanning is a complex chemical process used to transform perishable raw hides and skins into durable leather. Unfortunately, as a result, high levels of pollution are released into the water. Raghava Rao and his team at the Central Leather Research Institute (CLRI) in Adyar have modified the process to make it into an eco-friendly, cost-efficient method.

The scientists observed that simply reversing the order of the tanning and post-tanning steps can drastically improve the process. By also promoting non-chemical-based pre-tanning methods, they have reduced the amount chemicals released by 82% and made an energy saving of nearly 40% (Journal of Chemical Technology and Biotechnology, doi: 10.1002/jctb.1727).

As per Rao, The significance is tremendous in the context of environmental challenges being faced by the leather industry. Most importantly, no loss of the leather quality was observed when compared with conventional tanning methods......... Posted by: Kevin      Read more         Source

October 4, 2007, 9:32 PM CT

What Makes Quantum Dots Blink

In order to learn more about the origins of quantum dot blinking, scientists from the U.S. Department of Energy's Argonne National Laboratory, the University of Chicago and the California Institute of Technology have developed a method to characterize it on faster time scales than have previously been accessed.

Nanocrystals of semiconductor material, also known as quantum dots, are being intensively investigated for applications such as light-emitting diodes, solid-state lighting, lasers, and solar cells. They are also already being applied as fluorescent labels for biological imaging, providing several advantages over the molecular dyes typically used, including a wider range of emitted colors and much greater stability.

Quantum dots have great promise as light-emitting materials, because the wavelength, or color, of light that the quantum dots give off can be very widely tuned simply by changing the size of the nanoparticles. If a single dot is observed under a microscope, it can be seen to randomly switch between bright and dark states. This flickering, or blinking, behavior has been widely studied, and it has been observed that a single dot can blink off for times that can vary between microseconds and several minutes. The causes of the blinking, though, remain the subject of intense study......... Posted by: Kevin      Read more         Source

October 2, 2007, 8:43 PM CT

Nanotechnology: not just for geeks

Say nanotechnology, and geeks imagine iPhones, laptops and flash drives. But more than 60 percent of the 580 products in a newly updated inventory of nanotechnology consumer products are such un-geeky items as tennis racquets, clothing, and health products.

Maintained by the Project on Emerging Nanotechnologies at www.nanotechproject.org/consumerproducts, the updated inventory includes Head NanoTitanium Tennis Racquets, Eddie Bauer Water Shorts with Nano-Dry technology, Nano-In Foot Deodorant Powder/Spray, and Burts Bees sunscreen with natural Titanium Dioxide mineralmicronized into a nano sized particle.

Since the Project on Emerging Nanotechnologies launched the worlds first online inventory of manufacturer-identified nanotech goods in March 2006, the number of items has increased 175 percentfrom 220 to 580 products. There are 356 products in the health and fitness categorythe inventorys largest categoryand 66 products in the food and beverage category. One of the largest subcategories is cosmetics with 89 products. All are available in shopping malls or over the Internet. The list includes merchandise from such well-known brands as Samsung, Chanel, Black & Decker, Wilson, L.L. Bean, Lancome and LOreal.

The nanomaterial of choice appears to be silverwhich manufacturers claim is in 139 products or nearly 25 percent of inventoryfar outstripping carbon, gold, or silica......... Posted by: Kevin      Read more         Source

October 1, 2007, 10:26 PM CT

Finger Prints at Warp Speed

Scientists at the University of Warwick have devised a means of identifying partial, distorted, scratched, smudged, or otherwise warped fingerprints in just a few seconds.

Prior techniques have tried to identify a few key features on a finger print and laboriously match them against a database of templates. The University of Warwick scientists consider the entire detailed pattern of each print and transform the topological pattern into a standard co-ordinate system. This allows the scientists to "unwarp" any finger print that has been distorted by smudging, uneven pressure, or other distortion and create a clear digital representation of the fingerprint that can then be mapped on to an "image space" of all other finger prints held on a database.

This unwarping is so effective that it also for the first time allows comparison of the position of individual sweat pores on finger print. This has not previously been possible as the hundreds of pores on an individual finger are so densely packed that the slightest distortion prevented analysts from using them to differentiate finger prints.

The "unwarping" of distorted, damaged or partial prints is not the only benefit of the new technology. The system created by the Warwick scientists is also able to give almost instantaneous results. Instead of laboriously comparing a print against each entry in a database any new print scanned by the system is unwarped and over laid onto a virtual "image space" that includes all the fingerprints available to the database. It does not matter whether it's a thousand or a million fingerprints in the database the result comes back in seconds......... Posted by: Kevin      Read more         Source

October 1, 2007, 9:35 PM CT

Nanotube forests grown on silicon chips

Engineers have shown how to grow forests of tiny cylinders called carbon nanotubes onto the surfaces of computer chips to enhance the flow of heat at a critical point where the chips connect to cooling devices called heat sinks.

The carpetlike growth of nanotubes has been shown to outperform conventional "thermal interface materials." Like those materials, the nanotube layer does not require elaborate clean-room environments, representing a possible low-cost manufacturing approach to keep future chips from overheating and reduce the size of cooling systems, said Placidus B. Amama, a postdoctoral research associate at the Birck Nanotechnology Center in Purdue's Discovery Park.

Scientists are trying to develop new types of thermal interface materials that conduct heat more efficiently than conventional materials, improving overall performance and helping to meet cooling needs of future chips that will produce more heat than current microprocessors. The materials, which are sandwiched between silicon chips and the metal heat sinks, fill gaps and irregularities between the chip and metal surfaces to enhance heat flow between the two.

The method developed by the Purdue scientists enables them to create a nanotube interface that conforms to a heat sink's uneven surface, conducting heat with less resistance than comparable interface materials currently in use by industry, said doctoral student Baratunde A. Cola......... Posted by: Kevin      Read more         Source

September 27, 2007, 10:08 PM CT

Nanotubes To Detect and Repair Cracks in Aircraft Wings

Adding even a small amount of carbon nanotubes can go a long way toward enhancing the strength, integrity, and safety of plastic materials widely used in engineering applications, as per a new study.

Scientists at Rensselaer Polytechnic Institute have developed a simple new technique for identifying and repairing small, potentially dangerous cracks in high-performance aircraft wings and a number of other structures made from polymer composites.

By infusing a polymer with electrically conductive carbon nanotubes, and then monitoring the structure's electrical resistance, the scientists were able to pinpoint the location and length of a stress-induced crack in a composite structure. Once a crack is located, engineers can then send a short electrical charge to the area in order to heat up the carbon nanotubes and in turn melt an embedded healing agent that will flow into and seal the crack with a 70 percent recovery in strength.

Real-time detection and repair of fatigue-induced damage will greatly enhance the performance, reliability, and safety of structural components in a variety of engineering systems, as per principal investigator Nikhil A. Koratkar, an associate professor in Rensselaer's Department of Mechanical, Aerospace and Nuclear Engineering......... Posted by: Kevin      Read more         Source