Tag: digest-golf

Wires smaller in diameter than light waves boost solar cell efficiency

Electron micrograph of indium phosphide (InP) nanowires. Each is 180 nanometers in diameter; this diameter allows them to capture more light, making them effective in a photovoltaic solar cell. Wallentin et al. In the continuing quest to create solar cells, researchers seek new materials, use clever techniques, and look for novel physical phenomena to extract the maximum electricity out of sunlight for the lowest cost. One method of extracting more power at a lower cost relies on creating arrays of nanowires that stand vertically on inexpensive substrates. In contrast to the material in ordinary solar cells, nanowires use less material, can potentially be built with less costly materials, and in principle trap more light thanks to the geometry of the arrays. However, most nanowire solar cells are currently outperformed by their conventional counterparts. A new effort used indium phosphide (InP) nanowires with diameters smaller than the wavelength of the light they were trapping. That trick enabled Jesper Wallentin and colleagues to reach comparable efficiencies and slightly higher voltage than a conventional InP solar cell. While the wires only covered 12 percent of the surface area, they exploited a principle known as resonant trapping to extract over half as much current as a full planar cell of InP. This approach could lead to even greater efficiency at lower cost for solar cells. Many candidates for the next generation of photovoltaic (PV) solar cells are being investigated. Research in this area has two goals that don’t always overlap: maximizing the efficiency of converting sunlight into electric current, and reducing cost per unit of electricity. The advantage of nanowire-based cells lies in using a lot less material, since the entire surface need not be covered in PV material. Additionally, the wires themselves can be fabricated from relatively inexpensive semiconductor materials. Read 7 remaining paragraphs | Comments

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Wires smaller in diameter than light waves boost solar cell efficiency

All backscatter “pornoscanners” to be removed from US airports

Bloomberg is reporting that the TSA will be removing all of the remaining backscatter X-ray machines from US airports. The removal isn’t because of health concerns—instead, the machines’ manufacturer, Rapiscan Systems , failed to meet a US Congress-imposed deadline for altering the machines’ software to produce “generic passenger images,” according to the report. TSA assistant administer for acquisitions Karen Shelton Waters, speaking on behalf of the agency, noted that Rapiscan Systems would absorb the cost for the scanners’ removal, and that the removal is unrelated to Rapiscan’s alleged falsification of the machines’ abilities to protect passengers’ privacy. Nor does the removal appear to be related to ongoing questions about the safety of the backscatter X-ray technology. The CEO of OSI systems, Rapiscan’s parent company, says that rather than pitching the expensive machines into the garbage bin, the TSA will be relocating them to other government agencies. In total, there are 174 Rapiscan backscatter X-ray machines that will be pulled from airports and relocated, on top of the 76 that were  removed last year. Read 1 remaining paragraphs | Comments

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All backscatter “pornoscanners” to be removed from US airports

FCC adds spectrum to Wi-Fi—but you likely need a new router to use it

Jason Alley The Federal Communications Commission last week said it will add 195MHz of spectrum to Wi-Fi’s 5GHz band. This move is designed to relieve congestion in Wi-Fi networks, particularly in areas of widespread simultaneous usage like airports and sports stadiums . It could help your home network too, but not right away—routers available in stores today may not be able to use the new spectrum at all . Finding out definitively whether today’s routers will support the new spectrum is difficult, partly because the FCC still has to issue specific rules governing its use. We’ve hit up router vendors and other industry people to find out whether software updates might let current routers access the new spectrum. While the results were a bit muddled, it seems safe to say no one is guaranteeing today’s routers will get the benefit of the new 195MHz. Even the latest routers supporting the ultra-modern 802.11ac standard may be left behind. Cisco refused to comment at all, telling us only “Cisco has not made any announcements about this so cannot discuss at this time.” Buffalo told us “the chip vendors will need to work on it” and that “they will at least to have to make changes to the hardware driver. … The magnitude of that change will determine if Buffalo is able to use the same hardware.” Read 21 remaining paragraphs | Comments

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FCC adds spectrum to Wi-Fi—but you likely need a new router to use it

New features, new fixes: OS X Server’s six-month checkup

It has now been roughly half a year since the release of Mountain Lion . If Apple sticks to its new yearly release cadence for new OS X versions, that means we’re probably about halfway to OS X 10.9. That doesn’t mean the OS has stood still, though—two point updates have since tweaked the operating system’s functionality and stability, and this is even more true of OS X’s buttoned-up cousin, OS X Server . While Windows Server rarely picks up major new features outside of service packs, OS X Server is like the client version of OS X in that it sometimes takes a couple of point updates for its features to stabilize. Since July, we’ve received two point updates for OS X Server, and they’ve changed things around enough that it merits revisiting our original guide and pointing out what has changed. We’ll be focusing on the major user-facing changes here, but for a complete list of everything that has been changed and fixed you may also want to look at the complete release notes for OS X Server 2.1.1 and 2.2 . Read 14 remaining paragraphs | Comments

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New features, new fixes: OS X Server’s six-month checkup

Is Dell looking to kill PCs with “Project Ophelia”?

Dell’s Project Ophelia: an Android-based thin client that you can put in your pocket for around $50, eventually. Dell Dell is reportedly investigating a move to take the company private in a leveraged buy-out to clear the decks for a radical repositioning of the company. And according to a report from Atlantic Media’s Quartz , that includes relaunching Dell’s desktop and mobile business around a brand-new product: a computing device the size of a thumb-drive that will sell for about $50. Dell announced its pocket client PC, called ” project Ophelia ,” on January 8, and demonstrated it at CES. Developed by Dell’s Wyse unit, Ophelia uses a Mobile High-Definition Link (MHL) to draw power to boot from an HDTV display, or it can be powered off a USB port. It has integrated Bluetooth and Wi-Fi capability for connecting to a keyboard, a mouse, and the network, and it runs the Android 4.1 (Jelly Bean) operating system with all of the functionality of a tablet. It can also be used to power virtual instances of other desktop operating systems on a remote server or in the cloud. In other words, it’s a fusion of Wyse’s thin client technology modeled after the capabilities of a Google Chromebook—except it can be carried in a pocket. The main drawbacks are that few HDTVs currently support MHL—though such support can be found in a number of Dell flat-panel displays. Read 2 remaining paragraphs | Comments

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Is Dell looking to kill PCs with “Project Ophelia”?

New report shows Congress’ favorite BitTorrent downloads

Congress has become gun-shy about putting together Internet-related legislation after the attempt to pass SOPA generated unprecedented public outrage, but Internet piracy is still on its radar. Still, it turns out that digital copies of pirated movies and TV shows aren’t just the subject of committee debates on Capitol Hill—they’re also being downloaded onto Capitol Hill computers. A post today in US News & World Report’s tech blog published new information from anti-piracy forensics company ScanEye , a company that offers BitTorrent monitoring services in the name of fighting piracy. The ScanEye report [ PDF ] shows apparently pirated movie files being downloaded via IP addresses associated with the US House of Representatives. Congressional employees downloaded episodes of Glee , CSI , Dexter , and Home and Away in October and early November. There are more TV episodes downloaded than movies, but the report also shows downloads of films, such as Iron Sky , which was downloaded by a Congress-owned computer on Oct. 4; Life of Pi , downloaded on Oct. 27; and the Dark Knight Rises , downloaded on Oct. 25. Another download listed is Bad Santa 2 , a movie which has not been released yet. Read 1 remaining paragraphs | Comments

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New report shows Congress’ favorite BitTorrent downloads

Microsoft releases emergency update to patch Internet Explorer bug

Microsoft has released an emergency update to patch a security vulnerability in Internet Explorer that is being exploited in attacks aimed at government contractors and other targeted organizations. The patch fixes a “use after free” bug in versions 6, 7, and 8 of the Microsoft browser and will be automatically installed on affected machines that have automatic updating enabled, Dustin Childs, the Group Manager of the company’s Trustworthy Computing program wrote in a blog post published Monday . The unscheduled release comes just six days after Microsoft’s most recent monthly Patch Tuesday batch of security updates, but it was pushed out to counter an experienced gang of hackers who have infected websites frequented by government contractors to exploit the vulnerability. Monday’s update came hours after Oracle released an unscheduled patch to fix a critical vulnerability in its Java software framework. As Ars reported last week , the zero-day Java exploits were added to a variety of exploit kits that criminals use to turn compromised websites into platforms for silently installing keyloggers and other malware on the machines of unsuspecting visitors. Read 3 remaining paragraphs | Comments

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Microsoft releases emergency update to patch Internet Explorer bug

Adobe almost does something amazing by accident

It seemed like an intriguing deal. An old version of Adobe Creative Suite—the 2005 vintage CS2, to be precise—became freely downloadable from Adobe, with nothing more than a free-to-create Adobe ID required from users. Although basically useless for Mac users, as CS2 is only available for PowerPC, for Windows users this is a powerful, if not quite cutting edge, suite of graphics apps. This looked like a clever move from Adobe. Photoshop is widely held to be one of the most routinely pirated applications there is. In making an old but still servicable version of the software it appeared that Adobe was offering a good alternative to piracy: instead of using a knock-off copy of CS6, just use CS2. A free CS2 would also go some way toward starving alternative applications of oxygen. Given the choice between a free copy of CS2 and downloading, say, the GIMP, one imagines that many users would plump for the commercial application. It’s more of a known quantity, with a more polished user interface. And Photoshop is, frankly, the gold standard of bitmap image editing. Even an older version has a prestige that GIMP doesn’t. This is not to say that CS2 is necessarily superior to the GIMP; it may or may not be. It doesn’t really matter; Photoshop has a reputation and respect that the GIMP doesn’t have, and even if some might argue that it was undeserved, it influences the decisions users make. Read 11 remaining paragraphs | Comments

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Adobe almost does something amazing by accident

Apple says Do Not Disturb scheduling is broken until January 8

After reports that iOS 6’s new Do Not Disturb feature stopped resetting according to schedule on New Year’s Day, Apple says scheduling won’t work until next Tuesday, January 8. The Do Not Disturb feature was added to iOS 6 in order to silence what might otherwise be distracting notifications, like those during a meeting or while sleeping. Users can manually turn Do Not Disturb on or off, or can set a scheduled time for Do Not Disturb to kick in automatically and then reset later. For instance, many users set Do Not Disturb to turn on around bedtime and reset the following day. However, users discovered on January 1 that Do Not Disturb did not automatically reset as scheduled. Furthermore, after manually resetting, it wouldn’t engage as scheduled that evening. Read 2 remaining paragraphs | Comments

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Apple says Do Not Disturb scheduling is broken until January 8

“Neuristor”: Memristors used to create a neuron-like behavior

A cartoon showing spikes of activity traveling among neurons. UC Berkeley Computing hardware is composed of a series of binary switches; they’re either on or off. The other piece of computational hardware we’re familiar with, the brain, doesn’t work anything like that. Rather than being on or off, individual neurons exhibit brief spikes of activity, and encode information in the pattern and timing of these spikes. The differences between the two have made it difficult to model neurons using computer hardware. In fact, the recent, successful generation of a flexible neural system required that each neuron be modeled separately in software in order to get the sort of spiking behavior real neurons display. But researchers may have figured out a way to create a chip that spikes. The people at HP labs who have been working on memristors have figured out a combination of memristors and capacitors that can create a spiking output pattern. Although these spikes appear to be more regular than the ones produced by actual neurons, it might be possible to create versions that are a bit more variable than this one. And, more significantly, it should be possible to fabricate them in large numbers, possibly right on a silicon chip. The key to making the devices is something called a Mott insulator. These are materials that would normally be able to conduct electricity, but are unable to because of interactions among their electrons. Critically, these interactions weaken with elevated temperatures. So, by heating a Mott insulator, it’s possible to turn it into a conductor. In the case of the material used here, NbO 2 , the heat is supplied by resistance itself. By applying a voltage to the NbO 2 in the device, it becomes a resistor, heats up, and, when it reaches a critical temperature, turns into a conductor, allowing current to flow through. But, given the chance to cool off, the device will return to its resistive state. Formally, this behavior is described as a memristor. Read 4 remaining paragraphs | Comments

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“Neuristor”: Memristors used to create a neuron-like behavior