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June 18, 2006, 10:58 AM CT

Chemists Direct Silicon Oxide

Chemists Direct Silicon Oxide

Chemistry often seems to operate at random. However, scientists from the Max Planck Institute of Coal Research and the International Max Planck Research School "SurMat" have been able to change that: they grew silica particles from a solution onto a surface in such a way that a pattern of tiny little cones was regularly formed. Every silica cone was made of numerous spirals sitting on top of each other, and every spiral was made of tubes, in which the silica grouped itself around micelles of long-chain organic molecules. These kinds of selected hierarchical structures, which are exactly defined at large and small scales, were unknown to scientists except in nature, for example in bones, wood, and sea shells. Now, however, they can be grown in test-tubes - and that could allow engineers to produce even smaller optical and electronic components (Advanced Materials, April 18, 2006).

Bones are light and stable. That is because they are built optimally, at the smallest and largest levels. Their smallest elements are bound to fibrils, which fold together to make lamellae. These, in turn, organise themselves into girders that form a scaffolding, which has inspired even/also? structural engineers. Materials scientists call this kind of highly selected structure "hierarchical". Now, chemists from the Max Planck Institute of Coal Research in Mülheim an der Ruhr, Germany, have created a selected hierarchical structure from silica particles for the first time. It was made from a reaction solution in which very different forms of silica particles were able to grow. A silicon compound was mixed with an amine dragging a long tail of fatty acid. The amine molecules assemble micelles, which form long threads, and the silica accumulates on these threads. If the scientists dip an untreated support into the solution - for example, a lightly contaminated glass plate - the particles form random deposits: sometimes cone-shaped, sometimes a double cone, sometimes fibre-like shapes.........

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June 17, 2006, 1:35 PM CT

Hot Wheels For Wheelchair Users

Hot Wheels For Wheelchair Users
Style has rarely been a priority in industrial design for the disabled - until now that is. Designed in Hungary, the Kenguru is a car specially designed for wheelchair users. The car's interior space has no front seat - just a space built to house the driver's own wheelchair so all he/she has to do is simply roll in through the extra large car doors and into position.

The wheelchair locks into place, within easy reach of the car's controls which are centred around a joystick. It's light years away from the current options for disabled drivers, which involve having to hoist themselves into the driver's seat of standard cars.

by Billy T........

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June 15, 2006, 0:13 AM CT

Controlling The Computer By Thought

Controlling The Computer By Thought
Controlling a computer just by thought is the aim of cerebral interfaces. The engineer from Pamplona, Carmen Vidaurre Arbizu, has designed a totally adaptive interface that improves the performance of currently existing devices in, reducing the time needed to become skilled in their operation and enhance the control that users have over the interface. Moreover, according to Ms Vidaurre, the majority of the population is capable of using it.

The results appear in the PhD thesis, Online Adaptive Classification for Brain-Computer Interfaces, defended recently at the Public University of Navarre.

Cerebral interface.

A cerebral interface or brain-computer interface (BCI) allows people with communication problems to relate to their surroundings using a computer and the electrophysiological signals from the brain. The actual interface with which Carmen Vidaurre has worked with is based on electroencephalograms (EEG) of the individual, although there are others that use signals recorded from electrodes fitted directly into the brain.

The user and the interface are highly interdependent "systems" that, up to recently, adapted to each other independently. In the past, when a non-experienced individual started to use a BCI, the systems were unable to supply feedback, i.e. the individual was unable to see the results of their brain patterns on the screen.........

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June 12, 2006, 11:33 PM CT

Prettier World Of Computer Modeling

Prettier World Of Computer Modeling
Taking issue with the perception that computer models lack realism, a Sandia National Laboratories researcher told his audience that simulations of the nanoscale provide researchers more detailed results - not less - than experiments alone.

The invited talk by Eliot Fang was delivered to members of the Materials Research Society at its recent semiannual general meeting.

Sandia is a National Nuclear Security Administration laboratory.

Fang derided the pejorative "garbage in, garbage out" description of computer modeling - the belief that inputs for computer simulations are so generic that outcomes fail to generate the unexpected details found only by actual experiment.

Fang not only denied this truism but reversed it. "There's another, prettier world beyond what the SEM [scanning electron microscope] shows, and it's called simulation," he told his audience. "When you look through a microscope, you don't see some things that modeling and simulation show".

This change in the position of simulations in science - from weak sister to an ace card - is a natural outcome of improvements in computing, Fang says. "Fifteen years ago, the Cray YMP [supercomputer] was the crown jewel; it's now equivalent to a PDA we have in our pocket".

No one denies that experiments are as important as simulations - "equal partners, in fact," says Julia Phillips, director of Sandia's Physical, Chemical, and Nanosciences Center.........

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June 11, 2006, 12:46 AM CT

FUSEing Carbon Planets

FUSEing Carbon Planets
Researchers using NASA's Far Ultraviolet Spectroscopic Explorer, or FUSE, have discovered abundant amounts of carbon gas in a dusty disk surrounding a well-studied young star named Beta Pictoris.

Asteroids and comets orbiting Beta Pictoris might contain large amounts of carbon-rich material, such as graphite and methane. Planets forming from or impacted by such bodies would be very different from those in our solar system and might have methane-rich atmospheres, like Titan, a moon of Saturn.

The star and its emerging solar system are less than 20 million years old, and planets may have already formed. The abundance of carbon gas in the remaining debris disk indicates that the star's planets could be exotic, carbon-rich worlds of graphite and methane. Or conversely, the scientists say, Beta Pictoris and its environs might resemble our own solar system in its early days.

A team led by Dr. Aki Roberge of NASA Goddard Space Flight Center in Greenbelt, Md., presents the FUSE observation in the June 8 issue of Nature. The new measurements make Beta Pictoris the first disk of its kind whose gas has been comprehensively studied. The discovery settles a long-standing scientific mystery about how the gas has lingered in this debris disk yet raises new questions about the development of solar systems.........

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June 11, 2006, 9:38 AM CT

On Track To Win Case Against iTunes

On Track To Win Case Against iTunes
On 25th January, the Consumer Council lodged a complaint with the Consumer Ombudsman against iTunes Music Store Norge for breach of fundamental consumer rights.

Among other things, the decision clearly states that the terms of agreement demanded by iTunes are unreasonable with respect to Section 9a of the Norwegian Marketing Control Act. Moreover, it is unreasonable that the agreement the consumer must give consent to is regulated by English law. That iTunes disclaims all liability for possible damage the software may cause and that it may alter the rights to the music, are also considered unreasonable. iTunes must now alter their terms and conditions to comply with Norwegian law by the 21.of June.........

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June 11, 2006, 9:32 AM CT

A Sixth Sense

A Sixth Sense

That gave Jarrell and Haworth a new direction: Could they obtain that effect deliberately, extending the sense of touch into a sense of magnetism?

Todd Huffman, a graduate student at Arizona State University with a background in neuroscience, joined the project and brainstormed with Jarrell and Haworth about how, and where, to best implant a powerful magnet. He helped come up with the most effective design for an implant, and eventually became the first recipient. "The fingertip was chosen because of the high nerve density, and because the hands are constantly interacting with the environment, increasing the chances of sensing electromagnetism in the world," Huffman says.

"We chose the ring finger primarily because of its size and relatively low importance in gripping action, so there was plenty of room for the implant and a lower chance of physically damaging the implant," Huffman explains. Jarrell puts it more bluntly, writing about the procedure in a BMEZine article from March: "'If you had to lose or seriously damage one of your fingers, which would it be?' This was our answer." But nobody's finger fell off, and Huffman's results were better than they'd imagined.........

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June 11, 2006, 8:00 AM CT

Computing Material Truths

Computing Material Truths
It can take three decades before a new alloy makes its way from a glimmer in a scientist's mind to,say, the body of an airplane. That's because the development of alloys requires years of experiments to characterize the materials' mechanical properties. But what if you could model those characteristics in a computer? UC Berkeley engineer Daryl Chrzan is doing just that. He uses computational materials science to predict the properties of materials from the bottom up. His research could impact fields as diverse as nanotechnology and aeronautics.

"The intent of our work is to start with the properties of atoms and predict the larger scale properties that we experience everyday," says Chrzan, a professor in the Department of Materials Science and Engineering.

Already, scientists use computational tools to gain insight into the optical and electronic properties of certain materials. Predicting the mechanical properties, how a piece of metal will bend, for example, is a much harder problem though. That's because the number of degrees of freedom of a typical solid, how a number of ways the atoms can move, is "enormous," Chrzan says. A typical cubic centimeter of a metal contains 10 to the 22nd (10 followed by 22 zeros) atoms. Storing even the initial conditions of those atoms would require more computer memory than exists in the world, he explains. The difficulty is compounded by the fact that the structure of a material is not symmetric--defects are what allow it to bend in the first place.........

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June 10, 2006, 7:58 PM CT

Producing Bio-ethanol From Agricultural Waste

Producing Bio-ethanol From Agricultural Waste
Research conducted by Delft University of Technology has brought the efficient production of the environmentally-friendly fuel bio-ethanol a great deal closer to fruition. The work of Delft researcher Marko Kuyper was an important factor in this. His research in recent years has greatly improved the conversion of certain sugars from agricultural waste to ethanol. On Tuesday 6 June, Kuyper received his PhD degree for his research into the subject.

The search for alternatives to the current, oil-based, fuels is the focus of great interest around the world. One of the most attractive alternatives is bio-ethanol - alcohol produced from agricultural crops. At present, bio-ethanol is only made from sugars derived from corncobs, sugar beets, grain and sugarcane, with the help of baker's yeast. A great number of by-products result from the cultivation of these crops, such as straw and corn husks. It would be a major step forward if this leftover material, which also largely consists of sugar, could be used for the production of bio-ethanol. This would allow agricultural land to be used more efficiently and at the same time prevent competition with food supplies.

Until recently, the problem was that the complex mixture of sugars that makes up these leftover materials could not be efficiently converted into ethanol by the baker's yeast. Delft University of Technology, however, has recently devised a solution for this, which is achieved by genetically modifying the baker's yeast. The Delft scientists have inserted a gene (derived from a fungus that is found in elephant faeces) into baker's yeast, allowing it to convert an important sugar type, xylose, into ethanol, thereby making the production of bio-ethanol from supplies of leftover materials possible.........

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June 10, 2006, 7:51 PM CT

Synthesizing Complex Surfaces

Synthesizing Complex Surfaces Illustration of NIST's new gradient surface for materials research: a graded co-polymer
Credit: NIST
Scientists from the National Institute of Standards and Technology (NIST) have demonstrated an elegantly simple technique for synthesizing a wide variety of complex surfaces that vary in a controlled fashion across a test strip. The new technique is so flexible that it can be applied to surface science experiments ranging from developing better paints to exploring the bonding of proteins to cell membranes.

So-called "gradient composition surfaces"--their chemical composition changes gradually across the surface--have been shown to be powerful research tools for rapid, high-throughput testing of complicated surface properties, but they can be tricky to build. The new NIST technique described in a recent paper in Advanced Materials* coats a silicon wafer with a brush-like copolymer surface, varying the relative concentration of two components, or monomers, of the polymer along the length of the substrate. The dense polymer brush provides a controlled interaction surface at the top while effectively masking the underlying substrate.

The heart of the NIST technique is a combined microfluidic mixer and reaction chamber. The two components are injected into the mixer with gradually changing flow rates and mix thoroughly before filling a thin reaction chamber holding the silicon wafer substrate. Once the solution leaves the mixing region, the narrow dimensions of the reaction chamber inhibit further mixing, so the varying composition ratios through the chamber remain stable while the solution polymerizes on the substrate.........

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