Microbes turn electricity directly to methane

(PhysOrg.com) -- A tiny microbe can take electricity and directly convert carbon dioxide and water to methane, producing a portable energy source with a potentially neutral carbon footprint, according to a team of Penn State engineers.
Microbes turn electricity directly to methane

"We were studying making in microbial electrolysis cells and we kept getting all this methane," said Bruce E. Logan, Kappe Professor of Environmental Engineering, Penn State. "We may now understand why."

Methanogenic microorganisms do produce methane in marshes and dumps, but scientists thought that the organisms turned hydrogen or organic materials, such as acetate, into methane. However, the researchers found, while trying to produce hydrogen in microbial electrolysis cells, that their cells produced much more methane than expected.

"All the methane generation going on in nature that we have assumed is going through hydrogen may not be," said Logan. "We actually find very little hydrogen in the gas phase in nature. Perhaps where we assumed hydrogen is being made, it is not."

Microbial electrolysis cells do require an electrical voltage to be added to the voltage that is produced by bacteria using organic materials to produce current that evolves into hydrogen. The researchers found that the Archaea, using about the same electrical input, could use the current to convert and water to methane without any , bacteria or hydrogen usually found in microbial electrolysis cells. They report their findings in this week's issue of Environmental Science and Technology.

"We have a microbe that is self perpetuating that can accept electrons directly, and use them to create methane," said Logan.


DNA-Based Assembly Line for Precision Nano-Cluster Construction

March 29, 2009

UPTON, NY — Building on the idea of using DNA to link up nanoparticles — particles measuring mere billionths of a meter — scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have designed a molecular assembly line for predictable, high-precision nano-construction. Such reliable, reproducible nanofabrication is essential for exploiting the unique properties of nanoparticles in applications such as biological sensors and devices for converting sunlight to electricity. The work will be published online March 29, 2009, by Nature Materials.



A genetic technique successfully treats Duchenne muscular dystrophy in dogs

An international team of researchers has successfully treated dogs with the canine form of Duchenne muscular dystrophy (DMD), a rapidly progressing and ultimately fatal muscle disease that afflicts one out of every 3,600 boys. The researchers used a novel technique called exon skipping to restore partial function to the gene involved in Duchenne. The study, published in Annals of Neurology, gives hope that a similar approach could work in humans.



Solar Refrigerator: A Counterintuitive Prototype

The fridge was developed by mechanic engineering students Frederik Knop, Nicolás Ripoll, and Olivier Bernade, the last one a French exchange student.

The prototype is based on adsorption, which Wikipedia explains in the following way:

Absorptive refrigeration uses a source of heat to provide the energy needed to drive the cooling process.[...] The classic gas absorption refrigerator sends liquid ammonia into a hydrogen gas. The liquid ammonia evaporates in the presence of hydrogen gas, providing the cooling. The now-gaseous ammonia is sent into a container holding water, which absorbs the ammonia. The water-ammonia solution is then directed past a heater, which boils ammonia gas out of the water-ammonia solution. The ammonia gas is then condensed into a liquid. The liquid ammonia is then sent back through the hydrogen gas, completing the cycle.

Solar Fridge


Massive young star explodes 'before its time'

A massive young star seems to have exploded before its time, new Hubble Space Telescope images reveal. The star, the heftiest to have been linked to a supernova explosion, could challenge models of when stellar furnaces end their lives.

Stars heavier than about eight times the mass of the Sun end their lives in dramatic explosions when the nuclear furnaces at their cores run out of fuel and collapse into neutron stars or black holes.

The Hubble observations suggest the erstwhile star was a luminous blue variable, a massive star at least 50 times as heavy as the Sun that jettisons most of itself material into space in a series of outbursts. Eta Carinae, wedged between gigantic hourglass-shaped clouds of material that it sloughed off, is a classic example of this kind of star.

That classification was surprising, since luminous blue variables were not expected to explode. Stellar models predict that the stars should evolve further – into other stellar types, shedding all of the hydrogen on their surfaces and most of their mass, before running out of fuel and going supernova.

But "our star when it exploded still had some of its hydrogen envelope. It seems to have exploded before its time," says team member Douglas Leonard of San Diego State University in California.

One possibility, Leonard says, is that the star was actually close to death at its core, and for some reason did not lose all the hydrogen on its surface, appearing 'healthy'.



Desktop Factory 125ci 3D Printer

Until now, 3D printers have been large, expensive machines confined to the shops and design departments of major corporations and elite design firms. With the introduction of the Desktop Factory 3D printer, priced disruptively lower than the nearest competitive offering, Desktop Factory becomes the leader in high performance low-cost 3D printing technologies.



U.S. engineers find way to build a better battery

CHICAGO (Reuters) - U.S. engineers have found a way to make lithium batteries that are smaller, lighter, longer lasting and capable of recharging in seconds.

The researchers believe the quick-charging batteries could open up new applications, including better batteries for electric cars.

And because they use older materials in a new way, the batteries could be available for sale in two to three years, a team from Massachusetts Institute of Technology reported on Wednesday in the journal Nature.

Current rechargeable lithium batteries can store large amounts of energy, making them long-running. But they are stingy about releasing their power, making them discharge energy slowly and require hours to recharge.

Scientists traditionally have blamed slow-moving lithium ions -- which carry charge across the battery -- for this sluggishness.

However, about five years ago, Gerbrand Ceder and a team at MIT discovered that lithium ions in traditional lithium iron phosphate battery material actually move quite quickly.

"It turned out there were other limitations," Ceder said in a telephone interview.

Ceder and colleagues discovered that lithium ions travel through tunnels accessed from the surface of the material. If a lithium ion at the surface is directly in front of a tunnel entrance, it can quickly deliver a charge. But if the ion is not at the entrance, it cannot easily move there, making it less efficient at delivering a charge.

Ceder and colleagues remedied this by revamping the battery recipe. "We changed the composition of the base material and we changed the way it is made -- the heat treatment," Ceder said.

This created many smooth tunnels in the material that allow the ions to slip in and out easily. "The trick was knowing what to change," he said.

Using their new processing technique, the team made a small battery that could be fully charged in 10 to 20 seconds.

Ceder thinks the material could lead to smaller, lighter batteries because less material is needed for the same result.

And because they simply tinkered with a material already commonly used for batteries, it could be easily adapted for commercial use.

"If manufacturers decide they want to go down this road, they could do this in a few years," Ceder said.


The iPhone Becomes a Web Server

When those Apple advertisements tout "there's an app for just about anything," they aren't kidding. The latest example? A new iPhone application which just debuted in Japan's App Store transforms the handheld into a full-blown web server. Called "ServersMan@iPhone", the application allows your iPhone to appear just like any other web server on the internet.

The new application was developed by a Japanese operation called FreeBit, a Tokyo-based venture company known for providing its network platform to many VNO/ISPs (virtual network operator/Internet service providers).

Once the app is installed, PCs on the internet can access the iPhone to upload or download files through a browser or they can use the webDAV protocol. If the PC and the iPhone are on the same network, the PC can connect directly. If they are on separate networks, then FreeBit's VPN software will engage the connection.


Nanotubes That See Everything

Carbon nanotubes that respond to visible light might mean better solar cells and artificial retinas

Researchers at Sandia National Laboratories, in Livermore, CA, have created the first carbon-nanotube devices that can detect the entire visible spectrum of light. Their work might one day find a range of applications, including in solar cells that absorb more light, tiny cameras that work in very low light, and better artificial retinas.

Other researchers have demonstrated nanotubes that can detect light of specific wavelengths, including ultraviolet light, but never the entire visible spectrum of light. "This is a significant milestone," says George Grüner, a professor of physics and head of the Nano-Biophysics Group at the University of California, Los Angeles, who was not involved in the Sandia work.

The light sensor inside a digital camera--known as a charge-coupled device--converts light into an electrical signal because as photons bombard silicon, they create electron holes in the material. In contrast, carbon-nanotube light sensors work in a similar way to biological eyes. The nanotubes are decorated with three kinds of chromophores--molecules that change shape in response to a particular wavelength of light. This change in shape results in a change in the chromophores' orientations with respect to the nanotube that, in turn, changes the electrical conductivity of the nanotube in a way that can be measured to deduce the color and intensity of the light. The Sandia researchers used three different types of chromophores, which respond to either red, green, or blue bands of the visible-light spectrum.

The work is still at an early stage, but nanotube light sensors could have advantages over today's light-sensing chips. Most important, says Sandia researcher Xinjian Zhou, the devices are intrinsically high resolution and small. Their resolution is the same as the diameter of each nanotube--about one nanometer. And because an array of the nanotubes could be very small, light could be focused into a very small area, meaning that future devices would be very sensitive to low light levels. Also, nanotube light sensors could be printed on flexible polymer backings. This could make them cheaper to manufacture and also less irritating to biological tissue--an important consideration for retinal implants.