top Apple Sapphire Glass Supplier GT Advanced Files For Bankruptcy
A lot of companies used CIGS or CdTe.
"Used" is the key word here.
Because you can more easily use print and roll technologies and get fabrication costs down.
In theory. In practice, almost everybody who has tried it has failed. Thin film PV requires very large sheets of very thin layers that are also very uniform. It's not an easy task, and those who have solved it have not been eager to share how they did it. Nor have they been able to maintain their cost advantage against silicon PV.
Examples include FirstSolar and NanoSolar.
I'll grant you that First Solar is doing just fine, but not only has Nanosolar been unsuccessful, it doesn't even exist anymore. The only reasonably successful CIGS manufacturer to date (as defined by having a production volume similar to that of mid-sized silicon PV companies) has been Frontier Solar, and they ain't exactly cheap.
What the Chinese managed to do was lower the costs enough using conventional technology pushed to the limit that the advantages of low temperature manufacturing without requiring silicon ingot formation
Huh? Low-temperature manufacturing? No ingots? I monitor Chinese PV manufacturing practices like it's my job. Because it
is my job. I've been inside the fabs. I know the people who develop the technology. I assure you that they process their silicon and their wafers at the same temperature as everybody else, and that every single one of them is using ingot-based wafers. What the Chinese managed to do was develop an extensive local supply chain, then squeeze the crap out of everybody's profit margins when times got tough. Low labor cost played a role too, though with rapid wage inflation, the low labor intensity of solar cell production, and the increasing automation of solar module production, labor cost is not really much of a factor anymore.
top Terrible Advice From a Great Scientist
And from my experience, publishing dozens of peer-reviewed scientific articles, your experience is the exception. In fact, many sciences do not even utilize technicians. In the ten or so laboratories that I have worked in/with and the labs of the numerous professors that I talk with about their publication policies, exactly zero will allow someone authorship on a paper that they don't see until it's "basically finished." I'm sure some fall through the cracks, though certainly not the majority. However, I would not generalize my experiences and neither should you.
My experience -- also publishing dozens of peer-reviewed scientific articles -- is quite different from yours and much more like that of the poster to whom you were responding. More than once I've found out that I was a co-author on an article when the publishing company contacted me to let me know that my article had been received for submission. That's even a step beyond what the first poster mentioned -- I didn't even see the article that I supposedly co-authored until
after it was submitted for publication! I've also had my authorship credit manipulated so as to imply collaboration where there was none. It was accidental, I think, but afterward there was actually a story in the press about our non-existent collaboration. about a year and a half ago
top BitCoin Value Collapses, Possibly Due To DDoS
Good luck going to Safeway and buying your Jeno's frozen pizza with Euros, Yuan, or Yen, but they're all "real" money.
Good luck going to Safeway and buying your Jeno's frozen pizza with gold or silver, but a lot of people would have you believe that those are the
only "real" money. about a year and a half ago
top BP and Three Executives Facing Criminal Charges Over Oil Spill
Has Rep. Joe Barton apologized to BP for this yet?
top Stanford Ovshinsky, Hybrid Car Battery Inventor, Has Died
You can argue that he
commercialized amorphous silicon solar cells, but he most certainly did not invent them. That distinction goes to Chris Wronski and David Carlson at RCA.
top Can Anyone Become a Programmer?
Yes. I can.
top Towards a 50% Efficient Solar Cell
Why would the military focus so heavily on solar power?
It's not just solar, they are also very interested in wind, geothermal/ground source, and biofuels. But they think solar and wind have the most potential for their purposes (it's mostly only the Air Force interested in biofuels, for fueling their planes).
As for why, well, 80% of the convoys run in Iraq and Afghanistan are fuel convoys. On average, a soldier died or was wounded in one of every 46 of those convoys in 2010. And by the time you take into account the cost of the fuel and the expense of moving it, the military is paying something like 5-10 times the price you pay at the pump when you fill your gas tank.
What is this fuel used for? Some of it is used to power vehicles, of course, but the vast majority of it is used to provide electricity at remote and forward bases. They dump it in a generator, burn it, and wait for another convoy. On the other hand, the sun and the wind come to many of their locations without the need for a convoy.
The upshot of all of this is that with sufficient energy densities, the military could spend a whole lot more on solar panels and wind turbines that would seem justifiable to the average homeowner and still have it be economical -- I mean, just think of the money and lives that could be saved if a base could reduce the number of convoys it needs by 80%.
For all of that, you probably don't need cells with 50% efficiency, and I guess that's why TFA focuses on soldiers' gear instead of base power.
Your concern about a soldier contending with solar panels hanging off his back is a bit misplaced, I think. TFA says that at 50% efficiency, a 10-cm square panel is all that would be needed. That is already smaller than a single standard silicon cell in production today (standard is 15-cm square). And if you're worried about bad weather, sandstorms, and distractions then I would think that the last thing you want is a mechanical device with moving parts like foot pedals.
top Towards a 50% Efficient Solar Cell
It concentrates light from the entire sky into a narrow beam which is then split into different wavelengths. It says that right in the summary.
No, it doesn't say that in the summary. It says (incorrectly) that dichroic films are used to concentrate sunlight 20-200X, but nothing accurate about how it achieves that concentration. TFA says that for the concentrators to work, they would have to be pointed at the sun.
This is consistent with my personal experience. I've never seen a concentrator that can collect light from the entire sky and deliver it in a tight, focused beam. It's part of the reason concentrator systems have never quite managed to live up to their economic promise -- the diffuse portions of the solar spectrum go unused, reducing available energy by about 20% even in cloudless locations, and output drops to near zero as soon you have a few clouds or some haze.
And the dichroic films are used to split the light into its constituent parts, a bit like a prism. They play no role in the concentration of the light (though that is not your error).
top Websites Can Detect What Chrome Extensions You've Installed
If you don't like the behavior, you have quite a few options: Remove the extension, disable it,
go incognito when you don't want your extensions detected, or simply use another browser
... it seems I may have been a little too quick. When I visit the site running the extension-detection script in icognito mode, it is still able to detect my extensions. Now I wonder if disabling is even effective.
That said, I don't really think there's anything anybody can learn about me from the extensions I have installed -- at least, not anything that I wouldn't tell a total stranger. Since there are few extensions that don't interact with at least
one website, I think that's a good policy to follow even if you're a Firefox user.
top Websites Can Detect What Chrome Extensions You've Installed
This "exploit" looks more like begging the question to me. As far as I can remember, every single Chrome extension I have installed warned me that it might share data with the websites I visit before I installed it. It stands to reason that if an extension can share data with a website, that website can detect the extension, does it not?
I'm not saying that it's
ideal behavior, only that it seems to me that Chrome users have already been warned about it by Google itself. If you don't like the behavior, you have quite a few options: Remove the extension, disable it, go incognito when you don't want your extensions detected, or simply use another browser come immediately to mind.
top Power Demand From US Homes Expected To Fall For a Decade
Now maybe they can reverse that ridiculous incandescent light ban.
is no incandescent light ban, despite what Joe Barton (who co-sponsored the "ban" in the first place) would like you to believe. There is only a mandate for lights to become more efficient -- there is nothing in the law mandating that a particular lighting technology be phased in or out. In the end, it is likely a moot point anyway as market forces (partly as a result of European regulations, which the US Congress can do nothing about) have been pushing incandescent bulb manufacturers to close factories. In other words, with or without the law, incandescents are on the way out.
Like others, I would suggest LEDs. The prices are coming down fast, and the quality (and directionality, or lack thereof) is improving fast. Right now you still have to be pretty careful about what brand you buy and such -- the cheapest available bulb is likely to disappoint -- but by the time you have a hard time finding the incandescents you need I suspect LEDs will be much more viable.
top Ask Slashdot: Best Second Major For a Mechanical Engineer?
If I were in your position, I would stick with the ME for now. For one thing, you can do a BS + MS in the same amount of time (or less) that you can do a double-major BS, and the MS will get you farther in the job market than a double BS. When you become an upperclassman, you will have the opportunity to choose electives from other departments, and maybe even some grad-level courses, which will allow you some limited space to explore your interests. If you're interested in controls, look to EE departments -- where I did my MS and Ph.D., the EE controls classes were filled with students from other departments. Perhaps other universities offer those in the CS department, but I doubt it. And don't limit yourself to controls: If you're interested in biofuels, maybe look for some relevant chemical or bioengineering courses. You should also look for undergraduate research opportunities, summer internships, and student projects that coincide with your interests (e.g., a solar-car-racing team, if you're going to a university that has one).
When you finish your BS, you will have a lot more opportunities to specialize during an MS year. Not only can you switch fields if you like (e.g., switch to CS if you think it is really the way to go), but many universities offer specialized multi-disciplinary MS and certificate programs that are targeted to specific skill sets. My university offered quite a few of those -- off the top of my head, I remember computer-aided manufacturing, a multidisciplinary semiconductor processing program, and a business certificate aimed at succeeding in the global (as opposed to American) business environment. Universities are now adding similar programs targeted at biofuels and other alternative energy technologies.
top Scientists Breeding Super Bees
Only the '80s version had loud guitars and were called Stryper. They pollinated with Bibles, which might have helped churches but didn't do much for crops....
top National Academies Release Over 4,000 Free Science Books
I assume that you are aware that all these books were produced at US Government expense?
What gives you that idea? The National Academies are private organizations and the books they publish do not all result from federally funded research. Even so, the only publications that are automatically public domain are those of US government employees, regardless of the funding source.
top 80% Improvement In Solar Cell Efficiency
According to the article, part of the cell is composed of cadmium telluride. Both are toxic and various compounds of tellurium stink to high heaven. I wonder what happens if the cells get caught in a fire?
Right, the cell is composed of cadmium telluride, which is a binary compound. That is different from saying the cell is composed of cadmium and tellurium, which are separate atomic compounds with different properties. Toxicity and fire studies on cadmium telluride are ongoing, but so far they have found that cadmium telluride is not much of a threat. In fact, there was a chicken farm with cadmium telluride solar panels that burned down in Germany in late 2009, and while the place was treated by the authorities as a hazardous waste site, it was because of the chicken poo, not the cadmium telluride -- the burnt panels were collected and sent back to the manufacturer for recycling.
Put another way, assuming cadmium telluride is toxic and stinky just because it is composed of toxic, stinky elements is like assuming water is explosive because it is composed of explosive elements.
top Solar Cells Integrated In Microchips
The only way I can see that one wins on cost with this technology is if one has electronics that are so low-powered that they can be powered by an amorphous solar cell with an area equal to that of the circuitry itself. If you need a point of reference on the practicality of this requirement, I point you to your average solar-powered calculator, which has a solar cell area of several cm^2, and an active circuit area of probably less than 5 mm^2.
According to the
press release from University of Twente, they will use amorphous silicon or CIGS layers deposited on top of the integrated circuit. A pretty average amorphous silicon solar cell will produce 6 mW/cm^2 in full sunlight, and about 0.5 mW/cm^2 indoors. A CIGS cell, especially on such a small scale, could probably come close to tripling those figures (one of the biggest problems in realizing high CIGS cell efficiencies in mass production is getting layers of uniform quality over large areas, an issue that would be dodged in this case).
The press release from Twente says the power requirement is "well below 1 mW"; if you assume the actual requirement is 0.1 mW and you use CIGS cells then you could probably still get enough power to run the circuit indoors on 6-7 mm^2 area. That doesn't seem out of line to me, but then I'm a solar cell designer, not an IC designer....
top Oregon Senator Stops Internet Censorship Bill
That purpose is largely defeated by having the senators elected by popular vote. Now they have to represent their campaign donors and supporters more than they represent their states, same as the House.
That said, the primary reasons the 17th Amendment passed, which mandated election of senators by popular vote, were repeated bribery scandals and deadlocked state legislatures, causing some states to go years without one of their senators. Even before the 17th Amendment, some states used referenda to direct the legislatures as to who should be seated in the Senate, so some senators who were ostensibly chosen by the state legislatures were actually elected by popular vote.
At any rate, my point not that you are wrong, of course, but that the old way was not necessarily better than what we have now. I guess it comes down to whether you think it's better that a senator be beholden to shady state legislators or shady lobbyists....
top Why Unlocked Phones Don't Work In the US
Can you guys go from carrier to carrier and keep your number? Easy in the EU (though I don't think you can cross national borders and do that).
Yes, since sometime in the mid-'00s it has been US law that you have to be able to keep your number when you switch carriers, provided you are not also changing your geographic location. Different parts of the US have different area code (like city codes in the EU), and if you go somewhere that is served by a different area code then your carrier can force to you take a new number. This is always the case with landlines, but not always with mobile numbers -- I have a friend who has lived in Washington, DC for years with an Atlanta phone number -- but if you change geographical locations
and change your carrier then you generally have to get a new number.
top Why Unlocked Phones Don't Work In the US
I think you're missing the (rather badly made) point. Go to a Eurpoean mobile telco website (e.g. TMobile UK). It doesn't matter because the prices are all the same*. You can get a contract for £10, for a basic service, £15 with data and so on. That comes to £360 over two years = $580, give or take. So if your mobile bill is about $2000 over 2 years, you're effectively paying $1400 for the phone.
The problem with that logic, of course, is that in the US the telcos do not charge you a higher rate to subsidize your phone; rather, they lock you into a contract for a certain amount of time (usually 2 years) to guarantee a certain amount of cash flow from you.* Once the contract ends, you continue paying exactly the same rates. If you walk into a US carrier with an unlocked phone that you already own, you will pay the same rate as somebody who gets a "free" subsidized phone -- the only difference is that you will not be locked in to using their service for 2 years.
Looked at from
that perspective, you could argue that by not taking the subsidized phone you're paying hundreds of dollars to continue using the phone you already own (though a monthly rate plan is, of course, not your only option when you already own the phone, particularly if it is unlocked).
* Unless, that is, something has changed in the 2-1/2 years since I moved outside of the US.
top Aussie Gov't Says Wiretap Laws Fine, Telcos 'Wrong'
... then it will be easy to prevent criminal using the internet to escape. And it seems that, intentionally or no, that is the direction they're headed. These requirements sound like a recipe for drastically increasing expenses while simultaneously making the internet less useful to end-users. If they intend to pass those expenses on to their customers, I think it will be no surprise if an awful lot of Australians suddenly start remembering how well they got along in the pre-internet days.