I&T Weekly
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This week's headlines:
published: Jul 11, 2008
- Researchers claim superconductivity breakthrough
- Japanese researchers build artificial DNA
- MIT develops less-expensive way to shrink chip circuitry
- Brain implant helps stroke victim speak again
- Organic dye lets window panes harvest the Sun
- Game theory could save the world
- How jungle rot could power the future
- Chip may speed up internet 100 times
- Kodak develops 50-megapixel image sensor for digital cameras
- Nuclear fallout used to spot fake art
Researchers claim superconductivity breakthrough
Scientists at the University of Cambridge have published details of a key breakthrough in unravelling the mystery of room temperature superconductivity.
They write that materials which could potentially transport electricity with zero loss (resistance) at room temperature hold vast potential. Some of the possible applications include supercomputers, magnetically levitated trains, efficient magnetic resonance imaging, and lossless power generators, transformers and transmission lines.
Creating such materials has long eluded scientists, but the materials that are known to superconduct at the highest temperatures are ceramic insulators that behave as magnets before 'doping'. 'Doping' is a method of introducing impurities to a semiconductor to modify its electrical properties. After doping charge carriers (holes or electrons) into these parent magnetic insulators, they mysteriously begin to superconduct.
The Cambridge researchers have discovered where the charge 'hole' carriers that play a significant role in the superconductivity originate within the electronic structure of copper-oxide superconductors.
VNUnet UK / Nature, July 10, 2008
Japanese researchers build artificial DNA
Japanese scientists from the University of Toyama say they have created the world's first artificial DNA. The technology could be used in immensely powerful DNA computers.
Biological computing has the potential to make silicon-based systems obsolete and allow the development of tiny supercomputers many times more powerful than today's systems. DNA computers are constructed by using DNA as software and enzymes as hardware. By mixing the two and monitoring the resulting reactions, simple computer calculations can be performed.
The storage capacity of DNA is also far superior to that of silicon systems. Half a kilo of DNA would have a greater storage capability than all the hard drives in existence today. It is also much more power efficient. The new discovery would allow scientists to build custom DNA types optimised for computing.
VNUnet UK / Journal of the American Chemical Society, July 08, 2008
MIT develops less-expensive way to shrink chip circuitry
Researchers at MIT have developed a relatively inexpensive technique for shrinking the size of integrated circuitry found in microprocessors, computer memory, and other applications. The new technique has the potential of paving the way for next-generation computer components that deliver higher performance at the same or less power than current technology. This is the result of being able to pack more circuitry on the same size surface. In addition, the technique could be used in the development of circuitry for other applications, such as solar cells.
Specifically, the researchers have been able to etch 25-nanometer wide electron-carrying paths that are 25 nanometres apart. The thinnest circuitry available today in general microprocessors that are the brains of home and business computers is 45 nanometres.
The accomplishment of the MIT team is not in the size, but in the fact that it can etch the paths without the use of environmentally dangerous chemicals and other materials that add to the infrastructure cost in building today's processors. The new line-drawing method is similar to using a comb with three of every four teeth missing to draw lines in the sand. The researchers can move the comb over one line at a time to fill in the gaps, using sound waves as a guide. The tool developed for the process is called a nanoruler.
InformationWeek, July 09, 2008
Brain implant helps stroke victim speak again
Nine years ago, a brain-stem stroke left Erik Ramsey almost totally paralysed, but with his mental faculties otherwise intact. Today he is learning to talk again. In 2004, Ramsey had an electrode implanted in his speech-motor cortex by scientists at Neural Signals, US, who hoped the signal from Ramsey's cortex could be used to restore his speech.
Interpreting these signals proved tricky, however. Fortunately, a team from Boston University has been working on the same problem from the opposite direction. They have used information from brain scans of healthy patients to monitor neural activity during speech and found that the brain signals do not code for words, but instead control the position of the lips, tongue, jaw and larynx to produce basic sounds.
The Boston University group then developed software that could recognise and translate the patterns of brain activity during speech. When they teamed up with Neural Signals, they could use their software to interpret the signals from Ramsey's implanted electrode and work out the shape of the vocal tract that Ramsey is attempting to form. This information can then be fed to a vocal synthesiser that produces the corresponding sound. The software is now translating Ramsey's thoughts into sounds in real time, so Ramsey hears his 'voice' as he makes a sound, effectively bypassing the damaged region of his brain stem.
New Scientist, July 09, 2008
Organic dye lets window panes harvest the Sun
Harvesting sunlight before turning it into electricity could become easier thanks to an exotic organic dye developed at MIT. Coated onto an ordinary sheet of glass, the dye traps light inside the glass allowing it to be channelled to photovoltaic cells placed along the edges of the sheet. The technique could turn up to 20% of incident light into electricity at a fraction of the cost of conventional photovoltaic cells.
One way to reduce the cost of photovoltaic power is to focus light from a large area onto a small cell. In that way, a small cell can harvest light from a larger area. But the collecting optics must track the Sun's path across the sky, requiring expensive machinery and control systems. The dye-covered glass works differently. The dye molecules absorb sunlight over a wide range of visible wavelengths and then emit light at a longer wavelength.
About 80% of the emitted light then becomes trapped within the glass by an effect called total internal reflection, which guides the light within the sheet in the same way it guides light through optical fibres. Solar cells along the edges of the glass that are designed to work most efficiently at the longer wavelength then convert this trapped light into electricity.
New Scientist / Science, July 10, 2008
Game theory could save the world
New hope that people around the world can work together to combat global warming has come from a new theoretical study by researchers at the University of Lisbon and the Free University of Brussels. The team has been using 'game theory' - where mathematics is used to capture how people deal with each other - to show that a classic problem that undermines the ability of individuals to cooperate can be overcome, if people are diverse enough, as is the case when it comes to the 6.5 billion citizens of planet Earth.
Working together for the common good is crucial for progress in any society. But there is a basic problem with how to make the public share responsibility for common problems, such as climate change. This was illustrated by Garrett Hardin in his 1968 paper 'The tragedy of the commons'. He used the example of a public pasture. Each herdsman will keep adding cows to a common field, because the benefit of an additional cow goes exclusively to the herdsman. Because the cost of overgrazing is shared by all, the pasture will end up ruined.
Existing mathematical models treat individuals as equivalent, ignoring real-life diversity and population structure. So the team made the mathematics more realistic in this respect. The team shows that, contrary to expectations, the temptation to cheat declines as society becomes more diverse. Another discovery is that diversity also plays an important role in wealth distribution.
Daily Telegraph, July 09, 2008
How jungle rot could power the future
The genetics of 'jungle rot' may hold the key to more economical biofuel in the near future. Ethanol, the most common biofuel, is primarily made from grains, sugarcane and other crops. But it can also be made from cellulose Found in stems, bark and other plant parts.
To break down cellulose into fermentable sugars, however, requires special enzymes, called cellulases, which are expensive to produce. The biofuel industry has primarily obtained cellulase from the fungi Trichoderma reesei, which became infamous during World War II as jungle rot. The green mould devoured military tents and uniforms in the South Pacific.
To help reduce the cost of cellulase, an international group of scientists organised by the US Department of Energy's Joint Genome Institute (JGI, has now sequenced the DNA of one strain of T. reesei from the Solomon Islands. The hope is that this genetic information could allow the engineering of fungi or bacteria that can produce enzymes more efficiently than the current approach.
MSNBC / LiveScience, July 09, 2008
Chip may speed up internet 100 times
Scientists at the University of Sydney have developed a revolutionary optical chip that could improve internet speeds to up to 100 times.
The device, a photonic integrated circuit, could overcome the gridlock that occurs when information travelling along optical fibres at the speed of light has to be processed by slow, old-fashioned electronic components.
The chip, which the Australian team developed with Danish and Chinese colleagues, is made from chalcogenide, with tiny channels etched into the surface by lithographic techniques. The scratches on the surface of the glass act as a guide or switch for incoming data, akin to a train changing tracks, only rapidly.
The Age, July 10, 2008
Kodak develops 50-megapixel image sensor for digital cameras
Eastman Kodak said it has developed a 50-megapixel image sensor for digital cameras used by professional photographers.
The KAF-10100 produces exceptional resolution and detail in digital camera photography by producing images with a pixel array of 8176 x 6132, the highest resolution available in the popular 48 mm x 36 mm optical format used in medium-format photography, Kodak said.
Other features of the sensor include a newly designed 6-micron pixel instead of the 6.8-micron pixels used in current products for the commercial market. The smaller pixel reduces the 'click-to-capture' time for better camera response, lower power consumption, and more vivid colours.
InformationWeek, July 09, 2008
Nuclear fallout used to spot fake art
Scientists and art historians have developed what they say is a foolproof way of identifying forged works of art. They can distinguish between art created before 1945 and that produced after that date by measuring levels of the isotopes caesium-137 and strontium-90. These isotopes do not occur naturally but are released into the environment by nuclear blasts.
Over 2000 nuclear tests have been carried out since the first atomic explosion took place in New Mexico in July 1945. Among the by-products of these tests are caesium-137 and strontium-90, tiny quantities of which make their way into the Earth's soil and plants. It is then via the natural oils, such as linseed from the flax plant, that are used as binding agents in paints that these isotopes end up in post-1945 art.
The patented technique involves extracting tiny (of the order of 1 square millimetre) samples from paintings. The team were able to show that the two isotopes are not present in paintings from the first half of the 20th century, but that there were traces in paintings done in the 1950s.
PhysicsWorld, July 04, 2008