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Model of graphene structure Image: CORE-Materials
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Issue no. 29, 2011 Published: Sep 02, 2011 |
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Graphene finding could lead to super-fast internet | Portable ammonia factories could fuel clean cars | Portable microscope detects bacteria using holograms | Heat sensor provides fast, cheap TB detection method | Coral could hold key to sunscreen pill | Automation in the air dulls pilot skill | Laser beams create rain | Innovation prize set to reward African inventors | Dumping friends on Facebook helps make you secure |
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| Graphene finding could lead to super-fast internet |
Scientists from the Universities of Manchester and Cambridge have
devised a way of using graphene, the thinnest material in the world, to
capture and convert more light than previously, paving the way for
advances in high-speed internet and other optical communications. The
team found that by combining graphene with metallic nanostructures,
there was a 20-fold enhancement in the amount of light the graphene
could harvest and convert into electrical power.
Previous research has shown that electrical power can be generated by
putting two closely-spaced metallic wires on top of graphene and shining
light on the whole structure, effectively making a simple solar cell.
Due to the particularly high mobility and velocity of the electrons in
graphene, such graphene cell devices can be incredibly fast - tens or
potentially hundreds of times faster than communication rates in the
fastest internet cables currently in use.
The main stumbling block to practical applications has so far been the
cell devices' low efficiency. The problem is that graphene absorbs
little light - only around 3% - with the rest going through without
contributing to the electrical power.
The team solved this problem by combining graphene with tiny metallic
structures known as plasmonic nanostructures, which are specially
arranged on top of graphene. By using the plasmonic enhancement, the
light-harvesting performance of graphene was boosted by 20 times without
sacrificing any of its speed, they wrote in their study. |
| Reuters / Nature Communication
Aug 30, 2011 |
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| Portable ammonia factories could fuel clean cars |
Forget hydrogen: ammonia could be the answer to developing an
emissions-free fuel for cars. Ammonia produces just nitrogen and water
vapour when burned and, unlike hydrogen, it is relatively easy to store
in liquid form. That means transporting ammonia will not require costly
new infrastructure, according to researchers at Texas Tech University.
The team are developing a system to produce ammonia that can be
installed in filling stations. It first produces hydrogen from water
using electrolysis, then combines it with nitrogen from the air to
produce ammonia. To achieve this, the researchers have adapted the
Haber-Bosch process used to make ammonia industrially. Their version
works on a small scale and can make ammonia fairly cheaply.
Apiston rapidly compresses hydrogen and nitrogen, heating the gases to
400 °C. The mixture is fed into a chamber containing an iron oxide
catalyst, which sparks a reaction that further heats the gases and
generates ammonia. In a third chamber, the mixture decompresses and
cools down to room temperature. As it does so, it pushes against another
piston, from which mechanical energy is recovered and fed back to the
compressor, significantly cutting the process's power consumption.
Finally, a heat pump cools the mixture down to around -75 °C, liquefying
the ammonia for collection. |
| New Scientist
Sep 01, 2011 |
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| Portable microscope detects bacteria using holograms |
A cheap holographic microscope capable of detecting bacteria has been
developed by researchers at the University of California, Los Angeles
(UCLA). The handheld device uses a laser instead of lenses to identify
bugs in water, food or blood, and costs less than USD 100 to build.
Images can be uploaded to remote computers for further analysis.
Scientists hope the technology will improve healthcare in areas that
lack sophisticated diagnostic equipment.
The device has two modes of operation: a 'transmission' mode which can
analyse liquids such as blood and water, and a 'reflection' mode which
produces holographic images of denser surfaces. In reflection mode, the
microscope uses holography to create a 3D image of the sample being
studied. A key advantage of the design is that it employs cheap
electrical components instead of heavy and expensive lenses. Instead,
the microscope uses digital photo sensors, which can cost less than USD
15 each to produce. The researchers claim that the microscope can help
to monitor outbreaks of difficult-to-detect bacteria such as E. coli.
The device captures raw data, but its simple design means that
processing needs to be done on an external device with more computing
power. A user in the field can forward the image data to their mobile
phone, a laptop PC, or even upload it to an internet server. The team
believe the microscope could prove invaluable for medics working in
developing countries. |
| BBC News / Biomedical Optics Express
Sep 01, 2011 |
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| Heat sensor provides fast, cheap TB detection method |
A potentially cheaper and faster method for diagnosing tuberculosis (TB)
has been developed by researchers at the University of Basel,
Switzerland, who hope to test it in Tanzania.
The lack of a cheap, quick and accurate test makes it hard to control
the TB epidemic, which claims millions of lives every year in developing
countries. Culture-based methods are the gold standard for TB tests in
the developing world, but these can take nearly 60 days to give a
result. Molecular tests, such as GeneXpert, unlike culture-based
methods, are fast, accurate and can detect drug-resistant strains. But
the high costs and need for laboratories make access an issue for
developing countries.
The new method uses a microcalorimeter to detect heat produced by
Mycobacterium tuberculosis, the bacterium that causes TB, on a growth
medium. The study showed that detection takes 4-5 days but more
sensitive microcalorimeters could detect tuberculosis in 24 hours.
The team are working with the Swiss Tropical and Public Health Institute
to test the method at the Ifakara Health Institute in Tanzania. They
hope1 the test will be ready for use within two years although it might
take longer for the World Health Organization to endorse it. |
| SciDev / Applied Microbiology
Aug 30, 2011 |
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| Coral could hold key to sunscreen pill |
Scientists hope to harness coral's natural defence against the sun's
harmful ultraviolet rays to make a sunscreen pill for humans. The King's
College London team visited Australia's Great Barrier Reef to uncover
the genetic and biochemical processes behind coral's innate gift. By
studying a few samples of the endangered Acropora coral they believe
they can synthetically replicate in the lab the key compounds
responsible. Tests on human skin could begin soon.
The team plan to test a lotion containing the same compounds as those
found in coral. To do this, they will copy the genetic code the coral
uses to make the compounds and put it into bacteria in the lab that can
rapidly replicate to produce large quantities of it.
Scientists have known for some time that coral and some algae can
protect themselves from the harsh UV rays in tropical climates by
producing their own sunscreens but, until now, they didn't know how. The
work could ultimately mean that people might be able to get inbuilt sun
protection for their skin and eyes by taking a tablet containing the
compounds. But for now, the team are focusing their efforts on a lotion.
Another long-term goal of the study is to look at whether the processes
could also be used for developing sustainable agriculture in the Third
World. The natural sunscreen compounds found in coral could be used to
produce UV-tolerant crop plants capable of withstanding harsh tropical
UV light. |
| BBC News
Aug 30, 2011 |
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| Automation in the air dulls pilot skill |
Automated flight systems and auto-pilot features on commercial aircraft
are causing 'automation addiction' among today's airline pilots and
weakening their response time to mechanical failures and emergencies,
according to a new study by safety officials. This dangerous trend has
cost the lives of hundreds of passengers in some 51 'loss of control'
accidents over the past five years, the report found.
The technology behind the auto-pilot on commercial aircrafts only
requires pilots to do approximately three minutes of flying - during
take-off and landing - which has contributed heavily to the number of
'loss of control' accidents. The new study by the Federal Aviation
Administration (FAA) found that in two thirds of such accidents, pilots
had trouble manually flying the plane, or made mistakes with automated
flight controls. The FAA study says that pilots often 'abdicate too much
responsibility to automated systems'.
Airlines and regulators discourage or even prohibit pilots from turning
off the autopilot and flying planes themselves, according to the FAA
committee. The situation is even worse on commuter flights, where pilots
only manually operate the plane for 80 seconds out of a typical two-hour
flight. The FAA's report recommends that pilots take control of the
airplane more often in order to keep their skills sharp - so they are
prepared to react when the computers cannot. |
| ABC News / AP
Aug 31, 2011 |
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| Laser beams create rain |
Researchers from the University of Geneva used lasers to create water
droplets in the air, in a development which could eventually lead to
man-made weather systems. Although the technique, known as
laser-assisted water condensation, does not work in dry air scientists
were able to generate the droplets in very humid conditions over the
Rhône river in Switzerland.
The drops created - just thousandths of a millimetre across - were not
heavy enough to fall as rain but the experts hope that by making them
hundreds of times larger they will be able to create or prevent rainfall
in the right conditions.
The method works by firing laser beams into the air, creating nitric
acid particles which draw water molecules together and stop them from
evaporating. If the process is repeated in air currents that are blowing
towards mountains, the researchers hope the air will cool enough that
the droplets grow large enough to fall as rain. |
| Daily Telegraph / Nature Communications
Aug 31, 2011 |
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| Innovation prize set to reward African inventors |
African innovators and inventors who design products with the potential
to drive the continent's economic transformation may benefit from a new
awards scheme.
The Innovation Prize for Africa, worth USD 100,000, will be given for
the first time in February 2012 to the best innovators in three areas:
ICT, green technologies, and health and food security. The runner-up
will receive USD 50,000. The prize was announced last month by the UN
Economic Commission for Africa (UNECA) and the African Innovation
Foundation (AIF) based in Switzerland.
The aim of the prize is to support sustainable development by tapping
into the ingenuity of Africans to solve their own challenges. A
technical advisory committee will set different thematic areas for the
prize each year. The closing date for the first prize is 30 September.
The AIF hopes the prize will lead to increased commercialisation of
research and development, the adoption of emerging technologies, and
accelerated growth of the private sector in Africa. |
| SciDev
Aug 31, 2011 |
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| Dumping friends on Facebook helps make you secure |
Worried about loose-tongued friends sharing your private details with
the world? Culling the least discreet members of your social network
will help you feel more secure, but it's not a perfect solution. What if
your best friend is an offender?
Pritam Gundecha at Arizona State University in Tempe has a technique for
working out which friends are most likely to leak private information so
you can remove them, if you choose. Gundecha examined the relative
importance of data 2 million Facebook users elect to share with the
world and calculated the privacy risks friends pose to each other.
For example, around 80% of users are happy to disclose their gender, but
less than 1% share their home address. That suggests people publicising
their address aren't particularly privacy-conscious and you might want
to avoid them. Using these statistics, the researchers gave each user a
vulnerability score and worked out which friends will cause your
vulnerability score to go down should you unfriend them.
It turns out that unfriending the least discreet friend increases your
security by an average of more than 5% - worth it for a casual
acquaintance, but perhaps not so easy if your best buddy is a
blabbermouth. 'There are some friends you cannot remove, irrespective of
their vulnerability,' admits Gundecha. While the existing technique
doesn't take this kind of social importance into account, he is now
working on a version that does. |
| New Scientist
Aug 30, 2011 |
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