Persian Penguin Network

Researchers over at the National Renewable Energy Lab have reportedly made the first solar cell with an external quantum efficiency over 100 percent. Quantum efficiency relates to the number of electrons-per-second flowing in a solar cell circuit, divided by the number of photons from the energy entering. The NREL team recorded an efficiency topping out at 114 percent, by creating the first working multiple exciton generation (MEG) cell. Using MEG, a single high energy photon can produce more than one electron-hole pair per absorbed photon. The extra efficiency comes from quantum dots ‘harvesting’ energy that would otherwise be lost as heat. The cell itself uses anti-reflection coating on a transparent conductor, layered with zinc oxide, lead selenide, and gold. NREL scientist Arthur J. Nozik predicted as far back as 2001 that MEG would do the job, but it’s taken until now for the concept to leap over from theory. The hope is, of course, that this will lead to more competitively priced solar power, fueling the transport of the future.So in the future who owns the most desert wins the power race.. oh wait. isn’t that the middle easterners again. ;D

By Engadget

So, this is pretty… big. At this very moment, researchers at IBM are building the largest data drive ever — a 120 petabyte beast comprised of some 200,000 normal HDDs working in concert. To put that into perspective, 120 petabytes is the equivalent of 120 million gigabytes, (or enough space to hold about 24 billion, average-sized MP3’s), and significantly more spacious than the 15 petabyte capacity found in the biggest arrays currently in use. To achieve this, IBM aligned individual drives in horizontal drawers, as in most data centers, but made these spaces even wider, in order to accommodate more disks within smaller confines. Engineers also implemented a new data backup mechanism, whereby information from dying disks is slowly reproduced on a replacement drive, allowing the system to continue running without any slowdown. A system called GPFS, meanwhile, spreads stored files over multiple disks, allowing the machine to read or write different parts of a given file at once, while indexing its entire collection at breakneck speeds. The company developed this particular system for an unnamed client looking to conduct complex simulations, but Bruce Hillsberg, IBM’s director of storage research, says it may be only a matter of time before all cloud computing systems sport similar architectures. For the moment, however, he admits that his creation is still “on the lunatic fringe.”

By Engadget

A NEW way of providing crystal clear vision through an opaque layer could one day lead to a non-invasive technique for targeting cancer cells.

Some opaque materials will allow small amounts of light through if they are in a thin enough layer. But as light passes through the layer it is scattered in both time and space, so an image projected on one side emerges blurry and unfocused on the other.

Now Jochen Aulbach at the FOM Institute for Atomic and Molecular Physics in Amsterdam, the Netherlands, and colleagues, have found a way to sharpen things up. They figured that it should be possible to manipulate light so that the scattering it experiences as it passes through the layer leaves it focused.

The team achieved this through a trial and error process. They used a liquid crystal device which allows precise control of light, called a spatial light modulator (SLM), to manipulate 64-femtosecond-long laser pulses being projected onto a layer of paint. A detector measured the intensity and duration of the pulses that emerged from the other side. This information was then passed to a computer program that used it to tweak the SLM to make the next pulse arriving at the detector both brighter and less spread out in time.

In a paper to appear in Physical Review Letters, the team reports that it took about 10 minutes of repetition for the system to refine the tweaks sufficiently to create a coherent, bright pulse that was still just 115 femtoseconds long despite its tortuous route through the paint. By modifying the light pulse to travel through skin instead of paint it might be possible to deliver short, intense laser pulses to destroy cancer cells but leave nearby healthy cells intact.

Sylvain Gigan of the Langevin Institute in Paris, France, calls the time resolution impressive. “It is both very elegant and very effective,” he says.

By New Scientist