Moth eyes are covered in tapered nanostructures

Photovoltaics, which convert sunlight into electricity, have long been touted as one of the most promising solutions to our energy needs. Unfortunately, today’s devices reflect a lot of solar energy as heat, which means that solar power is currently not as cheap as other forms of energy. Now, however, researchers in the Netherlands have developed an anti-reflective coating based on the nanostructure of a moth’s eyes, which could reduce the reflection from photovoltaic cells and thereby make them more efficient.

Jaime Gomez Rivas and colleagues at the Philips Research Laboratories in Eindhoven say that their “moth-eye” technology is superior to other known anti-reflection measures. Additionally, they have developed a new eco-friendly production technique that can apply the coating with high precision.

More information is at Moth eyes inspire more efficient solar cell (free subscription may be required).

With the high cost of gasoline and diesel fuel impacting costs for automobiles, trucks, buses and the overall economy, a Temple University physics professor has developed a simple device which could dramatically improve fuel efficiency as much as 20 percent.

According to Rongjia Tao, chair of Temple’s Physics Department, the small device consists of an electrically charged tube that can be attached to the fuel line of a car’s engine near the fuel injector. With the use of a power supply from the vehicle’s battery, the device creates an electric field that thins fuel, or reduces its viscosity, so that smaller droplets are injected into the engine. That leads to more efficient and cleaner combustion than a standard fuel injector, he says.

Six months of road testing in a diesel-powered Mercedes-Benz automobile showed that the device increased highway fuel from 32 miles per gallon to 38 mpg, a 20 percent boost, and a 12-15 percent gain in city driving.

The results of the laboratory and road tests verifying that this simple device can boost gas mileage was published in Energy & Fuels, a bi-monthly journal published by the American Chemical Society.

Read the rest at Simple device which uses electrical field to boost gas efficiency developed by Temple University researcher.

Physicists find new material for storing hydrogen

Physicists in the US may have found a promising new class of material that can absorb and store large amounts of hydrogen. Adam Phillips and Bellave Shivaram of the University of Virginia measured around 12% by weight of hydrogen uptake in the metal-based composites. This is significantly higher than the target of 5.4wt% set by the US Department of Energy to support the development of hydrogen-powered vehicles — although the physicists say much work still needs to be done.

A low-cost, high-capacity hydrogen-storage medium is essential for the commercialization of hydrogen fuel-cell technologies in the future. While scientists have investigated various classes of material, such as carbon nanotubes, hydrogen-clathrate-hydrates and other nanostructured materials over the past few decades, no one satisfactory material has yet been found.

Adam Philips went on to say:

"It is critical to say that our work is at a very early stage," added Phillips. "While we have measured the hydrogen uptake, we have not yet been able to determine how the material desorbs. However, we are very optimistic about the possibility of scaling up and overcoming many of the other hurdles we now face."

You can read the whole article at http://physicsworld.com/cws/article/news/33614 (Free subscription may be required)

If this and other work like it pans out the pie-in-sky feel to the promises of a Hydrogen Economy may start to disappear.

When GWB was praising Hydrogen as a way to wean the US of its addiction to petroleum he was not completely candid.  Its important to remember that hydrogen is an energy carrier, and not an energy source. It is usually produced from other energy sources by burning petroleum, through wind power, or via solar photovoltaic cells. Hydrogen can also be extracted  from underground reservoirs of methane and natural gas,  from coal by coal gasification, or from oil shale by oil shale gasification.  Electrolysis (Remember Junior High Science and separating water into Oxygen and Hyydrogen?), which requires electricity, and high-temperature electrolysis/thermochemical production, which requires high temperatures (ideal for nuclear reactors), are two primary methods for the extraction of hydrogen from water.

If you understand the ways we are currently producing hydrogen in the quantities needed for fuel cells you can see that a "Hydrogen Economy" has benefits for humans such as cleaner burning cars but is NOT a solution to climate change or the geopolitical problems associated with petroleum extraction and consumption.

Researchers create ‘self-healing’ rubber

Rubbery materials can be easily stretched, but it is not easy to mend them when they break, as anyone who has ever had a punctured car tyre will know. Now, however, researchers in France have created a unique new rubber-like material that can “self-heal” at room temperature. If the material is snapped in half, the two torn pieces can be made to mend themselves simply by bringing the broken surfaces back in contact with each other (Nature 451 977).

The new “supramolecular rubber” has been created by Ludwik Leibler and colleagues at the Ecole Supérieure de Physique et Chimie Industrielles (ESPCI/CNRS) in Paris, France. It consists of “fatty acids” — short chains of carbon atoms — linked together via hydrogen bonds to form a macroscopic 3D network. The material behaves just like an ordinary rubber in that it can stretch to several times its normal length when pulled.

But if the material is cut in half, the two broken pieces of the rubber can self-heal when brought together and simply held in contact for a few minutes. The fracture mends and the material can be stretched and pulled in all directions again. “It is important to stress that the material is not self-adhesive,” Leibler told physicsworld.com. “The surfaces of the material are never sticky to the touch and feel like a rubber band or a plastic bag. Self-mending is possible even 12 hours after the fracture occurred.”

Read the rest over at http://physicsworld.com/cws/article/news/32970.  

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Physicists in the US have discovered a simple way to “store” light pulses in a material by converting them into sound waves. The technique, which involves just two lasers and a piece of standard optical fibre, could be used to create memory devices that could boost the performance of optical telecommunications networks.

Modern telecommunications networks transfer vast amounts of data along optical fibres in the form of packets of light pulses. However, if a network is extremely busy, two packets can arrive at the same node at the same time. Ideally, one packet would be stored for a very short period so that both packets could be processed in turn.