| Issue no. 32, 2009
Published: Sep 25, 2009
| Photon 'machine gun' could power quantum computers |
| Polymer battery breaks new records|
| New computing tool could lead to better crops and pesticides say researchers|
| Galactic-scale observatory planned |
| MIT retinal implant could help restore some vision|
| Honda shows small light 'personal mobility' device|
|Photon 'machine gun' could power quantum computers
|There is a simple rule of computing that holds true even in the quantum
world: increase the number of units of information available to boost
computing power. But raising the number of quantum bits, or qubits, has
proven tricky because of the difficulty of reliably producing entangled
particles. Now a team at Technion in Israel has designed a system that
should fires barrages of entangled photons with machine-gun regularity.
At the heart of the 'photonic machine gun' is a quantum dot - a
nanoscale crystal within a semiconducting device - chilled to a low
temperature. When a short, strong pulse of light hits the dot, one of
the electrons inside is raised to an excited state. As it 'relaxes' back
to its resting energy state it throws out a photon.
A practical version of the gun could be built within a few years,
according to the researchers.
| New Scientist / Physical Review Letters
Sep 25, 2009
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|Polymer battery breaks new records
|Researchers in Sweden have designed a simple polymer battery that has
the highest ever reported charge capacity and charging rate. The device,
which is made of cellulose fibres of natural origin coated with a 50 nm
polymer layer, is environmentally friendly and might find use in 'smart'
packaging and other paper-based products and textiles.
Batteries made from conducting polymers could be used in a variety of
new applications, like smart clothing and textiles. However, such
batteries suffer from slow charging rates - partly because thick layers
of polymer are needed to achieve high charge capacities. Now,
researchers at Uppsala University have made a novel nanostructured
high-surface-area electrode material for energy-storage applications
composed of cellulose fibres extracted from algae coated with a 50 nm
layer of polypyrrole.
The battery can be charged within just 11 seconds and has a capacity of
about 38-50 Ah/kg - the highest values reported to date for a polymer
paper-based battery. The paper has a surface area of 80 m2/g and
batteries based on the material can be charged with currents as high as
600 mA/cm2. What's more, they only lose 6% of their capacity after being
charged and discharged more than 100 times.
| NanoTechWeb / Nano Letters
Sep 18, 2009
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|New computing tool could lead to better crops and pesticides say researchers
|A new computing tool that could help scientists predict how plants will
react to different environmental conditions in order to create better
crops, such as tastier and longer lasting tomatoes, is being developed
by researchers at Imperial College London.
Scientists are keen to develop new strains of crops such as drought
resistant wheat and new pesticides that are more environmentally
friendly. However, in order to do this, they need to predict how the
genes inside plants will react when they are subjected to different
chemicals or environmental conditions.
The researchers have developed a prototype of the new tool, which they
are currently testing. It can analyse in a matter of minutes, instead of
months, which genes are responsible for different processes inside a
plant, and how different genes work together. It uses a type of computer
programming that relies on 'machine learning', a set of sophisticated
algorithms that allows a computer to 'learn' based on data that it is
analysing. The researchers say the tool will recognise complex patterns
in that data to find 'nuggets' of information about plant biology that
might previously have taken months or even years to find.
The 'machine learning' ability of the new tool means that researchers
can develop an understanding of different plants even when they are
lacking information about some aspects of their inner workings.
Sep 22, 2009
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|Galactic-scale observatory planned
|Physicists have drawn up ambitious plans to detect very low-frequency
gravitational waves - ripples in the fabric of space-time that general
relativity predicts ought to pervade the universe. But rather than
looking for them using existing facilities like the LIGO detectors in
the US, which are designed to detect tiny changes in the interference
patterns of laser beams sent down pairs of kilometre-long pipes
positioned at right angles to one another, the idea is instead to use
radio telescopes on Earth. The telescopes would measure tiny variations
in the output of pulsars spread thousands of light-years apart.
The galactic observatory, proposed by the North American Nanohertz
Observatory for Gravitational Waves (NANOGrav), would rely on minute
changes in the relative timing of emissions from different pulsars -
rapidly rotating neutron stars that emit very regular pulses of radio
waves. A gravitational wave passing between a pulsar and a radio
telescope affects the time it takes for the emissions to arrive, and so
an array of pulsars with different lines of sight to the Earth would
reveal the presence of any wave as well as its direction of propagation
This idea was first put forward in the late 1970s but requires such
high-precision measurements that it has not been technically feasible
until now. The NANOGrav team says that it should be possible to
correlate the output of 40 pulsars, each with a timing precision better
than 100 ns, within the next decade. This would allow astronomers to
observe gravitational waves with wavelengths of several light-years
coming from sources such as the black-hole binaries that form when
galaxies merge, as well as early-universe phenomena such as cosmic
strings or inflation.
Sep 22, 2009
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|MIT retinal implant could help restore some vision
|MIT engineers have designed a retinal implant for people who have lost
their vision from retinitis pigmentosa or age-related macular
degeneration, two of the leading causes of blindness. The retinal
prosthesis would help restore some vision by electrically stimulating
the nerve cells that normally carry visual input from the retina to the
brain. The chip would not restore normal vision but could help blind
people more easily navigate a room or walk down a sidewalk.
Patients who received the implant would wear a pair of glasses with a
camera that sends images to a microchip attached to the eyeball. The
glasses also contain a coil that wirelessly transmits power to receiving
coils surrounding the eyeball. When the microchip receives visual
information, it activates electrodes that stimulate nerve cells in the
areas of the retina corresponding to the features of the visual scene.
The electrodes directly activate optical nerves that carry signals to
the brain, bypassing the damaged layers of retina.
The research team recently reported a new prototype that they hope to
start testing in blind patients within the next three years, after some
safety refinements are made. Once human trials begin and blind patients
can offer feedback on what they're seeing, the researchers will learn
much more about how to configure the algorithm implemented by the chip
to produce useful vision.
Sep 23, 2009
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|Honda shows small light 'personal mobility' device
|Honda's new 'personal mobility' device looks like a unicycle, but all
you need to do to zip around on it - sideways as well as forward and
back - is lean your weight into the direction you want to go. The U3-X
was designed to be small, safe and unobtrusive enough to mingle with
pedestrians, according to Honda.
The single wheel on the U3-X is made up of many tiny motor-controlled
wheels, packed inside the bigger wheel, allowing the device to swerve in
any direction. It stands upright on its own. Sit on it as though it is a
stool, and shift your weight to drive. The thing maintains its own
balance as it scoots along at a speed of up to 6 kilometres per hour.
The device weighs less than 10 kilograms, runs on a full charge for an
hour, and has a lithium-ion battery. Honda said the machine is aimed at
the elderly. Japan is one of the most rapidly aging societies in the
world, and concerns are growing about helping the elderly get around.
| Google News / AP
Sep 24, 2009
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