Issue no. 30, 2009
Published: Sep 11, 2009 |
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 US scientists levitate mice to study low gravity |
| Google plans new mirror for cheaper solar power |
| Robot to be controlled by human brain cells |
| Ultra-strong Velcro-like fastener inspired by birds |
| Harnessing bacteria to make fuel cells more efficient |
| 'NanoPen' may write new chapter in nanotechnology manufacturing |
| Cement's basic molecular structure finally decoded |
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| US scientists levitate mice to study low gravity |
With the aid of a strong magnetic field, mice have been made to levitate
for hours at NASA's Jet Propulsion Laboratory (JPL). The method works
because a strong magnetic field distorts the movement of electrons in
water molecules, which in turn produces a magnetic field that opposes
the one applied. The net result is a repulsive effect which, if suitably
oriented and strong enough, can overcome the pull of gravity.
The scientists used a purpose-built levitation device containing a coil
of wire cooled to a few degrees above absolute zero so that it became
superconducting. Running a current through the wire creates a magnetic
field of 17 teslas, ten thousand times as strong as a typical fridge
magnet and 10 million times that of the Earth.
The magnetic field varies along the length of the coil. A water-
containing object placed at the base of the coil develops an opposing
magnetic field that generates a force twice that of Earth's gravity at
the bottom, Earth-like gravity in the middle, and zero gravity at the
top. The system can levitate water-based objects for days at a time.
The levitating mice could provide a testing ground for studying the
effects of space travel on humans, such as bone and muscle loss, and
changes in blood flow. The machine is better suited to such experiments
than the 'vomit comet' planes that simulate microgravity, or the
International Space Station. It makes it possible to dial in anything
between Earth and zero gravity for as long as needed, and at lower cost. |
| New Scientist
Sep 10, 2009 |
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| Google plans new mirror for cheaper solar power |
Google is disappointed with the lack of breakthrough investment ideas in
the green technology sector but the company is working to develop its
own new mirror technology that could reduce the cost of building solar
thermal plants by a quarter or more.
Google in late 2007 said it would invest in companies and do research of
its own to produce affordable renewable energy within a few years. The
company's engineers have been focused on solar thermal technology, in
which the sun's energy is used to heat up a substance that produces
steam to turn a turbine. Mirrors focus the sun's rays on the heated
substance. Google is looking to cut the cost of making heliostats, the
fields of mirrors that track the sun, by at least a factor of two.
Google hopes to have a viable technology to show internally in a couple
of months. It will need to do accelerated testing to show the impact of
decades of wear on the new mirrors in desert conditions.
Another technology that Google is working on is gas turbines that would
run on solar power rather than natural gas, an idea that has the
potential of further cutting the cost of electricity, the company says. |
| Reuters
Sep 10, 2009 |
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| Robot to be controlled by human brain cells |
A robot controlled by human brain cells could soon be trundling around a
British lab. Researchers at the University of Reading, UK, have already
used rat brain cells to control a simple wheeled robotMovie Camera.
Some 300,000 rat neurons grown in a nutrient broth and producing spikes
of electrical activity were connected to the output of the robot's
distance sensors. The neurons proved capable of steering the robot
around a small enclosure.
The team say that observing how their neuron culture responds to
stimulation could improve our understanding of neurological conditions
such as epilepsy. For instance, the way large numbers of neurons
sometimes spike in unison – a phenomenon known as 'bursting' – may be
similar to what happens during an epileptic seizure. If that behaviour
can be altered by changing the culture chemically, electrically or
physically, it might hint at potential therapies.
To make the system a better model of human disease, a culture of human
neurons will be connected to the robot once the current work with rat
cells is completed. This will be the first instance of human cells being
used to control a robot. One aim is to investigate any differences in
the behaviour of robots controlled by rat and human neurons. |
| New Scientist
Sep 09, 2009 |
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| Ultra-strong Velcro-like fastener inspired by birds |
Researchers have created a new type of Velcro-like fastener system made
from steel that may be useful in a range of settings, including
hospitals and the aviation industry. Borrowing its design from nature,
the new material comprises a series of hooks in the shape of birds'
heads that feed into a series of tiny loops along a perforated strip.
Velcro can seal with a relatively tight grip but still be released with
minimal effort. The trouble, however, with these fasteners is that their
gripping mechanism tends to break down when exposed to harsh conditions
such as high temperatures and aggressive cleaning chemicals. This
limitation leads to problems in industrial and applications.
Now, a team at the Technical University of Munich may have found a
solution to this problem. They have created a new hook-and-loop fastener
using steel, chosen for its high resistance to mechanical loads and
chemical corrosion. Steel can also deform significantly under high
stresses without fracturing and breaking the grip.
In developing the fastener, which is dubbed 'Metaklett', the researchers
tested a range of different hook designs. After combining laboratory
testing with computer simulations, the researchers settled on two
specific designs, both of which are resistant to chemicals and remain
fastened up to 800 °C. |
| PhysicsWorld
Sep 08, 2009 |
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| Harnessing bacteria to make fuel cells more efficient |
Bacteria that generate significant amounts of electricity could be used
in microbial fuel cells to provide power in remote environments or to
convert waste to electricity. Researchers at the University of
Massachusetts isolated bacteria with large numbers of tiny projections
called pili which were more efficient at transferring electrons to
generate power in fuel cells than bacteria with a smooth surface.
The researchers isolated a strain of Geobacter sulfurreducens that grew
prolifically on the graphite anodes of fuel cells. The bacteria formed a
thick biofilm on the anode surface, which conducted electricity. The
team found large quantities of pilin, a protein that makes the tiny
fibres that conduct electricity through the sticky biofilm. The pili on
the bacteria's surface seemed to be primarily for electrical conduction
rather than to help them to attach to the anode.
Microbial fuel cells could be used in monitoring devices in environments
where it is difficult to replace batteries if they fail but to be
successful they need to have an efficient and long-lasting source of
power. |
| ScienceDaily
Sep 10, 2009 |
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| 'NanoPen' may write new chapter in nanotechnology manufacturing |
Researchers in California are reporting development of a so-called
'NanoPen' that could provide a quick, convenient way of laying down
patterns of nanoparticles - from wires to circuits - for making
futuristic electronic devices, medical diagnostic tests, and other
much-anticipated nanotech applications.
In the new study, the team point out that researchers have already
developed several different techniques for producing patterns of
nanoparticles, which are barely 1/50,000th the width of a human hair.
But current techniques tend to be too complex and slow. They require
bulky instrumentation and take minutes or even hours to complete. These
techniques also require the use of very high temperatures to apply the
nanostructures to their target surfaces. Such limitations prevent
widespread application of such techniques.
The scientists say their NanoPen solves these problems. In lab studies,
the researchers used it to deposit various nanoparticles into specific
patterns in the presence of relatively low light and temperature
intensities. The process, which requires the use of special
'photoconductive' surfaces, takes only seconds to complete.
Manufacturers can adjust the size and density of the patterns by
adjusting the voltage, light intensity, and exposure time applied during
the process, the researchers say. |
| Science Daily / Nano Letters
Sep 08, 2009 |
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| Cement's basic molecular structure finally decoded |
In the 2,000 years since the Romans employed a naturally occurring form
of cement to build a vast system of concrete aqueducts and other large
edifices, researchers have analysed the molecular structure of natural
materials and created entirely new building materials such as steel,
which has a well-documented crystalline structure at the atomic scale.
Oddly enough, the 3D crystalline structure of cement hydrate - the paste
that forms and quickly hardens when cement powder is mixed with water -
has eluded scientific attempts at decoding, despite the fact that
concrete is the most prevalent man-made material on earth.
Scientists have long believed that at the atomic level, cement hydrate
closely resembles the rare mineral tobermorite, which has an ordered
geometry consisting of layers of infinitely long chains of three-armed
silica molecules (called silica tetrahedra) interspersed with neat
layers of calcium oxide. But the MIT team found that the
calcium-silica-hydrate in cement is not really a crystal but a hybrid
that shares some characteristics with crystalline structures and some
with the amorphous structure of frozen liquids, such as glass or ice.
With a validated molecular model the chemical structure can be
manipulated to design concrete for strength and environmental qualities,
such as the ability to withstand higher pressure or temperature,
according to the researchers. |
| MIT
Sep 09, 2009 |
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