An anonymous reader quotes a report from Ars Technica: Researchers from MIT and the Masdar Institute of Science and Technology, led by George Ni, describe a prototype design that boils water under ambient sunlight. Central to their floating solar device is a “selective absorber” — a material that both absorbs the solar portion of the electromagnetic spectrum well and emits little back as infrared heat energy. For this, the researchers turn to a blue-black commercial coating commonly used in solar photovoltaic panels. The rest of the puzzle involves further minimizing heat loss from that absorber, either through convection of the air above it or conduction of heat into the water below the floating prototype. The construction of the device is surprisingly simple. At the bottom, there is a thick, 10-centimeter-diameter puck of polystyrene foam. That insulates the heating action from the water and makes the whole thing float. A cotton wick occupies a hole drilled through the foam, which is splayed and pinned down by a square of thin fabric on the top side. This ensures that the collected solar heat is being focused into a minute volume of water. The selective absorber coats a disc of copper that sits on top of the fabric. Slots cut in the copper allow water vapor from the wick to pass through. And the crowning piece of this technological achievement? Bubble wrap. It insulates the top side of the absorber, with slots cut through the plastic to let the water vapor out. Tests in the lab and on the MIT roof showed that, under ambient sunlight, the absorber warmed up to 100 degrees Celsius in about five minutes and started making steam. That’s a first. The study has been published in two separate Nature articles: “Steam by thermal concentration” and “Steam generation under one sun enabled by a floating structure with thermal concentration.” Read more of this story at Slashdot.
Read this article:
Floating Solar Device Boils Water Without Mirrors
MTorrice writes: After a nice long bout of aerobic exercise, some people experience what’s known as a “runner’s high” — a feeling of euphoria coupled with reduced anxiety and a lessened ability to feel pain. For decades, scientists have associated this phenomenon with an increased level in the blood of beta-endorphins, which are opioid peptides thought to elevate mood. Now, German researchers have shown the brain’s endocannabinoid system—the same one affected by marijuana’s 9-tetrahydrocannabinol (THC)—may also play a role in producing runner’s high, at least in mice. Read more of this story at Slashdot. 
siddesu writes A popular ‘encryption’ package for Android that even charges a yearly subscription fee of $8, actually does nothing more than give false sense of security to its users. Not only is the app using a worthless encryption method, it also uses weak keys and ‘encrypts’ only a small portion of the files. One wonders how much snake oil flows through the app stores, from ‘battery savers’ to ‘antivirus’. What is the most worthless app purchase you made? Did you ask for a refund? Read more of this story at Slashdot. 
Windows/Mac/Linux: Calibre, one of the best free ebook managers out there (and a great tool for removing DRM ), released a big update this week. Calibre 2.0 includes a new editor function, comparison tool, support for Android phones on OS X, and more. Read more… 
Airplane tickets are one of the biggest costs of traveling, so cutting down the price on those can expand your travel budget in a huge way. If you’re planning to visit Europe, Business Insider has determined the nine cheapest airlines to fly to Europe. Read more… 
Trailrunner7 writes: As the uncertainty surrounding the end of TrueCrypt continues, members of the security community are working to preserve a known-good archive of the last version of the open source encryption software released before the developers inserted a warning about potential unfixed bugs in the software and ended development. The message that the TrueCrypt posted about the security of the software also was included in the release of version 7.2a. The OCAP team decided to focus on version 7.1a and created the verified repository by comparing the SHA2 hashes with files found in other TrueCrypt repositories. So the files are the same as the ones that were distributed as 7.1a. “These files were obtained last November in preparation for our audit, and match the hash reported by iSec in their official report from phase I of the audit, ” said Kenn White, part of the team involved in the TrueCrypt audit. Read more of this story at Slashdot. 
