Issue no. 4, 2009
Published: Jan 30, 2009 |
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 China builds super-sized radio telescope |
| Cheap, super-efficient LED lights on the horizon |
| Novel technology could produce cheap biofuel |
| Balloon power isn't just a load of hot air |
| Physicists raise serious LHC safety doubts |
| Alarm sounded over Wi-Fi networks |
| Invention: Sleepy driver sensor |
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| China builds super-sized radio telescope |
Construction has begun on a massive new 500m diameter radio telescope in
Guizhou Province, China, that will allow astronomers to detect galaxies
and pulsars at unprecedented distances. The facility, known as the
Five-hundred-meter Aperture Spherical Telescope (FAST), will boast a
collecting area equal to 30 football fields - more than twice as big as
the 305 m diameter radio telescope at Arecibo Observatory in Puerto
Rico, which has been the world's largest since it opened in 1964.
The geography and remoteness of FAST's site make it very radio-quiet.
The new telescope will sit in a natural karst depression that mimics the
shape of the collecting surface, simplifying the support structure and
shielding the telescope from stray human-generated radio waves. The
site's potential for long, uninterrupted observations - coupled with the
telescope's huge size - means that researchers will be able to detect
objects like weak, fast-period pulsars that are too faint to be measured
accurately by smaller instruments.
In addition to being big, FAST is designed to be flexible: a system of
motors attached to its 4600 panels will allow astronomers to change its
shape from a sphere to a paraboloid, making it easier to move the
position of the telescope's focus. This will allow the south-pointing
telescope to cover a broad swathe of the sky - up to 40 degrees from its
zenith, compared to the 20-degree-wide strip covered by Arecibo. |
| Physics World
Jan 27, 2009 |
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| Cheap, super-efficient LED lights on the horizon |
UK scientists have discovered a cheaper way to produce LED bulbs, which
are three times as efficient as fluorescent lamps.
Gallium nitride (GaN) LEDs have many advantages over compact fluorescent
lamps (CFLs) and incandescent bulbs. They switch on instantly, with no
gradual warm-up, and can burn for an average of 100,000 hours before
they need replacing. CFLs also contain small levels of mercury, which
makes environmentally-friendly disposal of spent bulbs difficult.
The cost of production has kept the LEDs far from homes and offices,
however. Gallium nitride cannot be grown on silicon like other
solid-state electronic components because it shrinks at twice the rate
of silicon as it cools. Crystals of GaN must be grown at 1000°C, so by
the time a new LED made on silicon has cooled, it has already cracked,
rendering the devices unusable.
Now researchers at the University of Cambridge have discovered a simple
solution to this problem. They included layers of aluminium gallium
nitride in their LED design. These layers shrink at a much slower rate
during cooling and help to counteract the fast-shrinkage of pure gallium
nitride. These LEDs can be grown on silicon as so many other electronics
components are. A 15-centimetre silicon wafer costs just USD 15 and can
accommodate 150,000 LEDs making the cost per unit tiny. |
| New Scientist
Jan 29, 2009 |
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| Novel technology could produce cheap biofuel |
A novel technology for synthesising chemicals from plant material could
produce liquid fuel for just over EUR 0.50 a litre, say German
scientists at the Karlsruhe Institute of Technology (KIT). But only if
the infrastructure is set up in the right way.
The novel technology is known as bioliq, and is able to produce a range
of different types of liquid fuel and chemicals from plant material such
as wood and straw. Bioliq involves first heating the plant material in
the absence of air to around 500°C. This produces a thick oily liquid
containing solid particles of coke termed biosyncrude.
The biosyncrude is then vaporised by exposing it to a stream of oxygen
gas, before being heated at high pressures to a temperature of around
1400°C. This gasification process transforms the liquid biosyncrude into
a mixture of carbon monoxide and hydrogen called syngas. After any
impurities are removed from the syngas, it can be catalytically
converted into a range of different chemicals and fuels, including
methanol, hydrogen and a synthetic version of diesel. |
| EurekaAlert / Biofuels, Bioproducts & Biorefining
Jan 29, 2009 |
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| Balloon power isn't just a load of hot air |
For those who dislike the sight of wind turbines on the horizon, would a
spectacular hot-air balloon farm be more acceptable?
Ian Edmonds, an environmental consultant with Solartran in Brisbane,
Australia, has designed a giant engine with a balloon as its 'piston'. A
greenhouse traps solar energy, providing hot air to fill the balloon. As
the balloon rises, it pulls a tether, which turns a generator on the
ground. Once the balloon has reached 3 kilometres, air is released
through its vent and it loses buoyancy. This means less energy is needed
to pull the balloon back down again, resulting in a net power gain.
For roughly the same cost as wind power, Edmonds has calculated that a
large 44-metre-diameter recreational balloon could generate 50
kilowatts, enough to supply energy to about 10 homes. Doubling the
diameter of the balloon would increase power production tenfold,
substantially reducing costs. |
| New Scientist / Renewable Energy
Jan 18, 2009 |
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| Physicists raise serious LHC safety doubts |
New research by three physicists has raised concerns over the safety of
the Large Hadron Collider (LHC), which is due to restart this summer.
Concerns had already been raised that the activities within the 27km
particle accelerator could create black holes, which could in turn
destroy the planet. A lawsuit was even filed to prevent the LHC from
operation which sparked ribaldry from internet users.
CERN, which operates the LHC, commissioned an extensive study which
concluded that, if black holes were formed by the LHC, they would last
for only milliseconds before extinguishing themselves. However, a new
study by Roberto Casadio of the University of Bologna, and Sergio Fabi
and Benjamin Harms of the University of Alabama, has concluded that the
black holes could survive for more than a second.
The danger would occur if the black holes stayed in existence long
enough to absorb material and become self-sustaining, but the physicists
say it is more likely that they would either collapse or stabilise at a
very small level and drift out into space. |
| VNUnet UK
Jan 29, 2009 |
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| Alarm sounded over Wi-Fi networks |
Wireless access points could be used by hi-tech criminals to spread
viruses and worms, warn researchers at Indiana University. Security
holes and the popularity of the devices in cities makes them ideal for
spreading malware, they found.
Using modelling methods from real diseases the team showed how a worm
could gradually infect all access points in urban areas. They found that
the majority of vulnerable access points would be hit in the first 24
hours of an outbreak. The simulation work showed that within two weeks
of an outbreak occurring 55% of Wi-Fi access points would be
compromised. In urban areas this could mean tens of thousands of people
were at risk, said the researchers.
The theoretical attack modelled by the team involved attempts to subvert
the firmware inside a Wi-Fi access point or router which keeps the
device running. Hi-tech criminals keen to subvert Wi-Fi access points
could rely on the fact that few people take basic steps to stop
unauthorised access to the device, said the researchers. The team
recommended that people be forced to change default passwords and
encouraged to use encryption - both of which can limit the ability of
wireless-borne malware to spread. |
| BBC News
Jan 27, 2009 |
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| Invention: Sleepy driver sensor |
Around 20% of accidents on multi-lane highways are the result of driver
fatigue. So the Japanese car maker Toyotahas developed a system to rouse
drivers before they quite literally drift off completely.
A camera watches the white lines on the road ahead to determine if and
how fast the car is veering towards or away from them. An onboard
computer then decides whether that kind of manoeuvre is appropriate for
the situation. If it is deemed potentially dangerous, the system raises
the alarm to wake the driver.
For example, a car regularly crossing white lines while accelerating and
braking is likely to be simply driving in city traffic. But wobbling to
and fro within a lane, or gradually veering across white lines while
moving at a constant high speed may indicate a driver falling asleep on
the open highway. If the driver is judged to be losing consciousness,
the computer raises an alarm to wake the driver. |
| New Scientist
Jan 23, 2009 |
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