Issue no. 18, 2008
Published: Jun 06, 2008 |
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 Nanosponges could soak up oil spills |
| IBM developing miniature pipes for chip cooling |
| Malicious software threatens internet economy |
| Mobile phones can help predict epidemics |
| Nanoscope peers beyond the limits of light |
| Scientists turn exhaust fumes into power |
| 'Scrubber' may clean air of CO2 emissions |
| German scientists develop bionic eye |
| Giant telescopes could be built from Moon dust |
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| Nanosponges could soak up oil spills |
Researchers at MIT have created a sheet of entwined nanowires that sop
up oil but leave water behind. The sponge, which resembles paper, can
absorb 20 times its weight in oil, which may make the technology useful
in cleaning up spills and separating contaminants from water.
The researchers say that the material should be easy to produce in large
quantities. The sponge can be reused after heating, which evaporates off
any oil or organic solvent the mesh has absorbed.
To make the nanowire membrane, the researchers adapted an existing
method to make nanowire sheets. They produced wires made from manganese
oxide that were roughly 20 nanometres in diameter and naturally
assembled into a wool-like tangle. The team added a layer of silicone to
the membrane to make it hydrophobic, or water repellent.
Because the membrane is mostly air, it functions like a sponge, drawing
in liquid through capillary action. But because the surfaces are
unfavourable to water, the membrane selectively absorbs hydrophobic
solvents such as oil. |
| Nature / MIT
May 30, 2008 |
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| IBM developing miniature pipes for chip cooling |
As chips get smaller and smaller, cramming more processing power into
ever-tinier spaces, the heat thrown off by the miniature circuits
becomes harder to manage. Cooling measures used now to avoid chip
meltdowns, including heat sinks made from heat-absorbing materials,
might not work on tinier scales.
In fact, in a future microprocessor design IBM is exploring - in which
chips are stacked vertically to save space and enhance performance,
rather than arrayed next to each other - the heat-to-volume ratio
exceeds that of a nuclear reactor. To address that, IBM researchers say
they could pipe water in between chips that are sandwiched together. The
system uses pipes that are just 50 microns wide. The tiny tubes are
sealed to prevent leaks and electrical shorts.
Even these micro amounts of water can handle prodigious cooling chores,
because water is much more efficient than air at absorbing heat. That is
why some high-end computers long have used water cooling. The new trick
here is that IBM expects to do it at the miniature scale, inside chips. |
| PhysOrg / AP
Jun 05, 2008 |
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| Malicious software threatens internet economy |
National economies and security interests face a growing threat from
malicious software, says a damning report by the Organisation for
Economic Co-operation and Development (OECD).
Communities involved in fighting malware 'offer essentially a fragmented
local response to a global threat,' says the report, which urges
international cooperation to combat the danger. The report cites
evidence that around one in four PCs in the US - or 59m - is already
infected with malware. A booming market in attack software and services
has also made attacks more sophisticated and cheaper to perform.
Most malware infections (93%) occur on home users' computers. However,
OECD research suggests that this can have a knock-on effect on national
industries reliant on online transactions such as banking. For example,
malware may deter people from using the internet to access more
efficient savings products.
Thirty-eight countries around the world now have national bodies focused
on computer security. But the OECD says international organisations and
agreements are needed to properly measure the impact of malware attacks
and counteract them. |
| New Scientist
Jun 02, 2008 |
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| Mobile phones can help predict epidemics |
A new study suggests that people, regardless of travel habits, follow
the same general patterns of motion, spending the bulk of their time in
a few favourite spots. The conclusions could help researchers devise
more accurate models of disease outbreaks.
Human travel routines affect how a virus will spread during an epidemic.
But monitoring large numbers of people is not easy. A 2006 study using
hundreds of thousands of dollar bills as surrogates found that a typical
bill circulated within a small area but could also travel long distances
when its owner went on a trip or vacation. It was not clear whether this
pattern reflected the movements of individuals, however, because a
dollar bill can easily change hands.
So researchers at Northeastern University in Boston turned to the cell
phone. They monitored 100,000 users for 6 months and recorded the
location of the cell phone tower that transmitted each call or text
message. The team found that most people stayed close to home, and a
select few regularly took long trips. This mixed profile suggests that
the typical journey seen in the dollar bill study had at least partially
captured the movements of multiple people rather than individuals. The
researchers then ranked each user's favourite spots and found that
regardless of how mobile they were, people returned over and over to a
few top locations with similar probability. |
| ScienceNow / Nature
Jun 04, 2008 |
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| Nanoscope peers beyond the limits of light |
The power of light microscopes to resolve fine details has just doubled.
The new technique can distinguish tiny structures inside cells, in
colour and 3D, even if they are only 100 nanometres apart.
The resolution achievable with light microscopy - the diffraction limit
- is normally restricted to about half the wavelength of visible light,
around 200 nanometres. If two objects are closer together than this,
they cannot be distinguished from each other and appear as one
structure. Electron microscopy, which uses much shorter wavelengths, can
visualise smaller details, but is limited to black and white images and
thin or very small specimens.
Now researchers at the Ludwig Maximilians University in Munich, Germany,
and the University of California in San Francisco, US, have found a new
trick to push past the diffraction limit. Shining structured patterns of
light on specimens creates an interference pattern cast by the tiniest
fine structures of the sample. This can be used to extract information
about their shapes even if they cannot be visualised directly. The
technique might make it possible to study in much greater detail how
chromosomes and other subcellular components are structured in space. It
could also distinguish DNA regions with active genes from those with
inactive genes - an important step for understand ageing and diseases. |
| New Scientist / Science
Jun 05, 2008 |
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| Scientists turn exhaust fumes into power |
Researchers at the Fraunhofer Institute for Physical Measurement
Techniques have published plans to develop a thermoelectric generator
which converts heat from car exhaust fumes into electricity.
Two-thirds of the fuel's energy is emitted in the form of heat. About 30
per cent is lost through the engine block, and a further 30 to 35 per
cent as exhaust fumes. To use this wasted energy the scientists are
developing thermoelectric generators that convert heat into electrical
energy by making use of a temperature gradient.
The temperatures in the exhaust pipe can reach more 700 then degrees
Celsius. The temperature difference between the exhaust pipe and a pipe
carrying engine cooling fluid can thus be several hundred degrees
Celsius. The thermoelectric converter makes use of this huge
differential. Driven by the flow of heat between the hot exhaust fumes
and the cold side of a coolant pipe, the charge carriers pass through
special semiconductors, thus producing an electric current similar to a
battery. The researchers say that the device could cut petrol
consumption by between five and seven per cent. |
| VNUnet UK
Jun 04, 2008 |
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| 'Scrubber' may clean air of CO2 emissions |
Scientists at Colombia University in New York claim to have made a major
breakthrough towards developing a machine that can 'suck' CO2 from the
air. Dubbed the 'scrubber' and small enough to fit in a cargo container,
it will hopefully provide a cost-effective means of removing up to a
tonne of CO2 each day from the air - roughly the equivalent amount
produced by a transatlantic flight.
However, while the scientists say the 'scrubber' is a major innovation
in the battle against climate change, they have stressed their invention
does not provide a magic solution to the problem of CO2 emissions.
Millions of the devices would need to be produced to capture all global
emissions, and the problem of disposing of the CO2 once it has been
trapped still remains.
The technology is based around absorbent plastic sheets called ion
exchange membranes that are routinely used to purify water. The critical
discovery the team is believed to have made is that humid air can cause
the membranes to 'exhale' the trapped CO2, meaning they are then ready
to be used again. The team is developing a prototype of the device. |
| The Scotsman
Jun 01, 2008 |
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| German scientists develop bionic eye |
German researchers at the Fraunhofer Institute for Microelectronic
Circuits and Systems IMS in Duisburg this week reported that a 12-year
project to develop a wireless implant that can restore vision to the
blind has been successful. They unveiled details of a fully implantable
visual prosthesis for patients who have lost their sight through
diseases of the retina.
Sufferers of retinitis pigmentosa have light sensitive cells in the
retina destroyed, but the connection of the nerve cells to the brain
remains intact. The scientists have bypassed the defects of the retina
by means of a visual prosthesis. The system comprises the implant and an
external transmitter integrated in a spectacle-frame. The implant system
converts the image patterns into interpretable stimulation signals, and
data and energy are transferred to the implant by a telemetric link.
Nerve cells inside the eye are then stimulated according to the captured
images. The intact cells are innervated by means of 3D stimulation
electrodes that rest against the retina like small studs. |
| VNUnet UK
Jun 02, 2008 |
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| Giant telescopes could be built from Moon dust |
Dust - often thought of as an impediment to lunar exploration - could be
put to good use to build giant telescopes on the Moon - perhaps some
large enough to fill entire craters, says a team of NASA researchers.
The team has devised a simple method to create a concrete-like substance
using a mixture of carbon nanotubes, epoxy and a crushed rock material
that NASA uses as a stand-in for Moon dust. Using the mixture, they
built a 30-centimetre disc. Then they added more liquid epoxy to its
surface and spun it, coating it with aluminium in a vacuum. They believe
the process could be scaled up to produce 20- to 50-metre-wide
telescopes on the Moon.
That would be useful since the limited fuel and cargo capacities of
rockets make it unfeasible to launch large mirrors or telescopes to the
Moon. To make a 2.4-metre mirror like Hubble's, the researchers
estimates the recipe would call for about 600 kilograms of Moon dust, 60
kg of epoxy, 6 kg of carbon nanotubes and less than a gram of aluminium.
The technique could also be used to build other structures on the Moon,
including reflectors for an array of solar panels, as well as habitats,
or igloos, for astronauts, they say. |
| New Scientist
Jun 04, 2008 |
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