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Comment: Re:Money? (Score 1) 263

by koolguy442 (#45413437) Attached to: Physicists Plan to Build a Bigger LHC

Well, the numbers are all there in the summary

Cost of LHC is $5B
This one would be 3-4x as large.
So I would assume $15B-20B.

According to Wikipedia (http://en.wikipedia.org/wiki/Superconducting_Super_Collider#Comparison_to_the_Large_Hadron_Collider), the LHC was only so cheap because it took over existing tunnels from the former Large Electron-Positron Collider (whose cost a cursory Google search does not reveal). Digging fresh tunnels will add much more expense to the project.

Comment: Re:pilkington method (Score 2) 102

The Pilkington method, as claimed in patent 2,911,759, describes a method for producing and manufacturing glass. Based on the wording of that patent, it seems only to have ever been considered for, only describes, and, therefore, only applies to what is traditionally thought of as "glass" - the hard clear stuff made mostly of silica. As well, it seems quite narrowly focused on such silica glass, effectively limiting its applicability to other materials. The patent in question here, 8,485,245 B1, talks about a superficially similar method used to manufacture amorphous metallic alloys, also known variously as bulk metallic glasses, liquid metals, and glassy metals. Since it's a method on a completely different materials system, it would indeed be eligible for patent protection. The earlier Pilkington patent also doesn't cover anything regarding the various temperature-controlled annealing and phase transformation steps outlined in claim 1 of the Crucible patent, though that part would be pretty obvious and obviously necessary to anyone skilled in the art of amorphous metallurgy.

Comment: Not to nay-say, but... (Score 5, Interesting) 127

by koolguy442 (#39095531) Attached to: Physicists Create a Working Transistor From a Single Atom

I hate being a nay-sayer, but the NYT article is making quite a spectacle about this whole thing. What the group has truly done is demonstrate a novel method for placing a single phosphorus atom within silicon and proceeded to measure the semiconducting properties of the resultant device with quite good precision. Because the doping is the result of a single atom, they can resolve more than just "on" and "off", and in fact can read three states from it, so it gets its quantum computing title.

As a materials scientist, I'm worried that they don't show any long-term data and all their results appear (from my not-so-thorough reading of the originating Nature Nanotechnology report) to be based on a single device. How repeatable is this result and how consistent are the signals across multiple devices? How far will the phosphorus atom diffuse over the lifetime of the device? Or even over the first few hours of its operation at room temperature? How closely can these devices be placed to each other on the silicon chip without getting cross-interference or depriving the dopant of its discrete quantum states? The dopants in a normal device aren't too terribly close to each other. And finally, how big must the surrounding structure be?

Don't get me wrong, this is excellent science and well deserving of its publication in such a prestigious journal, but the spectacle that the NYT is creating around this and the dreams of such a tiny device is a bit premature.

Comment: Re:Two-dimensional? (Score 4, Insightful) 160

by koolguy442 (#38915245) Attached to: Researchers Create Glass Just 3 Atoms Thick

The glass is a mere three atoms thick — the minimum thickness of silica glass—which makes it two-dimensional.

It's not two dimensional if it has a measurable thickness, which you stated in that same sentence. Unless you have a different definition of "two dimensional" than the rest of us.

Really? Graphene is 0.34 nm thick, and I'm quite certain that is a 2 dimensional material. In terms of graphene it's 3 dimensional after 3 layers. So the measurable thickness argument isn't valid

Graphene is most certainly not .34 nm thick. What you are quoting is the equilibrium spacing between one graphene sheet and the next in crystalline graphite. The true "thickness" of graphene is hard to gauge, actually. If you take the standard model of quantum mechanics, the carbon atoms within graphene are point particles, and therefore have no thickness. It is reasonable, then, to measure the extent of the electron clouds from the carbon. Since the electron clouds are statistical formulations, they theoretically extend to infinity. However, because I'm a materials scientist and not some fancy physicist with a deep, quantitative understanding of electron orbital theory, I would say a good guess is to say that the radius of the electron cloud around a particular atom is about equal to half the bond length between one carbon and the next. In this case, about 0.071 nm.

So if I were pressed to give an answer as to the thickness of a graphene sheet, not that it would generally matter in any context I'd think of, I'd call it 0.142 nm thick.

Comment: Re:Two-dimensional? (Score 4, Informative) 160

by koolguy442 (#38915127) Attached to: Researchers Create Glass Just 3 Atoms Thick

The glass is a mere three atoms thick — the minimum thickness of silica glass—which makes it two-dimensional.

It's not two dimensional if it has a measurable thickness, which you stated in that same sentence. Unless you have a different definition of "two dimensional" than the rest of us.

Your question can be answered in two ways. First, in the materials science community, it's common to denote a material or chunk of material that has a very high aspect ratio, for instance very large in one or two dimensions and small in size on the order of the atomic scale in the remaining directions as effectively one- and two-dimensional. In fact, quantum dots are thought of in materials science as generally zero-dimensional, even though they most certainly have more than one atom (and even if they comprised a single atom, the electron cloud extends in three dimensions). So, as far as the materials science and electron microscopy fields are concerned, this is two-dimensional.

Second, you tend to get your paper published in fancier journals and grab more headlines by having sensational things such as 2D (in this case) or quantum or some such buzzword in your title these days.

Comment: Re:What we don't know why or how? (Score 4, Interesting) 111

by koolguy442 (#34507858) Attached to: Video Shows Why Recharging Kills Batteries

TEM Comments
This experiment was actually quite a bit harder to carry out than you think. (I imagine, as I wasn't involved in this study but do similar work.) Doing these experiments is like traveling to the moon in that the principles are relatively simple, but it's the details that are hard. While operation of the TEM is relatively easy, preparation of samples is extremely tedious even when the sample is relatively robust and isotropic and it doesn't matter where you need to look on the sample. Constructing a TEM specimen with the intention of looking at a tiny little feature of some larger piece of material is extremely difficult, taking hours or days, if even possible. It's even more difficult to prepare a specimen and have the right equipment set up to control and observe dynamic processes, such as lithium discharge from a single nanofiber. And viewing dynamics in a complicated system, like a battery, which contains at a very minimum three active components, anode, cathode, and electrolyte, is another order of magnitude harder. Plus you have to find a way to make the thing less than 20 nanometers thick and get it into a microscope at high vacuum without breaking or contaminating it, which is nontrivial. There's also the cost of the equipment, which is between $500,000 and $10 million for the microscope itself and another couple hundred thousand dollars for the specialized probes required to do this experiment. I do this for a living myself, as do many people across the world who are either pursuing or already have PhDs in microscopy and analysis, and if it were easy, it'd've already been done and we'd be out of the job.

Battery comments
We understand pretty much exactly why batteries wear out. Though the anodes in "real" batteries are usually some form of graphite, which expands less than 10% versus the SnOx in the video (~250%), there is still jostling of all the little powders that form the battery upon charging and discharging that eventually lead to the individual particles separating from the electrodes as a whole and essentially becoming dead micro-paperweights within the battery cell. It's just very hard to image them dynamically in a realistic operation because air and water vapor tend to destroy the materials nearly instantly.

Comment: Out of date and short on detail (Score 1) 108

by koolguy442 (#33960646) Attached to: Degraded Electrodes Observed In Aging Batteries
This is some just really old news. Papers have been published on this and the other myriad sources of lithium battery degradation over the last several decades. In fact, this sort of coarsening, irreversibility, and poisoning are common in all such "nano" and even "micro" systems in which thermodynamics and kinetics are pitted against each other. For instance, at a three day international workshop on automotive lithium batteries half a decade ago, about a third of the talks were on various degradation mechanisms in these systems. On the other hand, this might be something completely knew that no one in the materials science or electrochemistry fields have heard of, but, being one of those people, and seeing the utter lack of detail in the news article and not being able to find the originating scientific publication, I doubt it. It looks like one of many articles on the subject that someone happened to pick up and submit. And yes, I'm a materials scientist and I study nano-scale materials, including battery electrodes.

Comment: Re:questions from a biologist (Score 2, Informative) 70

by anmida (#26727969) Attached to: Efficiently Producing Quantum Dots
There are a lot of different types of quantum dots. Some are colloidal (dots in a liquid) - others are buried or built into materials. The fluorescent dots that you are familiar with are the colloidal ones; some are made of CdSe, ZnSe, etc, and being in a liquid medium, of course they are injectable and can be used as biological fluorescent markers. In terms of color of light emitted, the bulk material emits at some characteristic color. With QDs, as you change their size, the light emitted changes color, even though you're using the same material. Larger dots emit at a longer wavelength (redder), smaller dots at higher wavelengths (bluer).

The other type of quantum dots, the ones with photovoltaic/electronic applications, tend to be dots that are buried or grown into another solid material. The "dots" that this researcher has created are of this type - basically it seems he's managed to create individual silicon atoms on a surface that have dangling bonds in a sea of non-dangling-bond Si. The fact that the dangling bond Si atoms are far-separated from each other makes them maintain their atomic energy levels instead of having their energy levels develop into bands, as what happens in typical crystalline material. It seems like these dots were developed for quantum computing purposes and are concerned with the wave functions of the electrons, as opposed to light emission and band gap energies.

Comment: Wouldn't exactly call it a quantum dot (Score 1) 70

by anmida (#26727039) Attached to: Efficiently Producing Quantum Dots
As someone who works with typical quantum dots, I find Wolkow's research interesting, but I wouldn't necessarily call what he's created a "quantum dot." Usually we are concerned with the bandgap shifting that is possible by changing the size of the dot. As I interpret his paper, it seems he's managed to create individual dangling-bond Si atoms surrounded by Si terminated by H. These dangling-bond states *handwaving explanation* seem to remain with quantized energy states instead of acting like the bulk material they're surrounded by, which have energy bands. It seems like he's interested more in electron tunneling effects for quantum computing rather than bandgap size manipulation. Maybe I'm just old-fashioned in how I think about quantum dots :p
Businesses

IT Job Market Is Tanking, But Not For Everyone 371

Posted by kdawson
from the jobs-available-but-not-for-you dept.
CWmike writes "Shortly after the COO of Automated HealthCare Solutions learned that Microsoft planned to cut 5,000 workers over the next 18 months, he and another employee of the medical services provider flew out to Redmond. AHCS now has more than 100 resumes, some of them from Microsoft employees, for about a dozen open positions. That's how the tech job market is these days: there's no doubt the market is tanking, but not for everyone. While numerous IT vendors are laying off workers, and corporate IT jobs are being lost as well, plenty of companies are still hiring. Microsoft's careers site lists more than 700 open jobs in the US, both technical and administrative positions. And IBM has about 3,200 jobs and internships listed worldwide, more than 550 of them in the US — even as it cuts thousands of workers in a move that it is describing not as a layoff, but an effort to 'match skills and resources with our client needs."

Comment: Re:Elimitate upselling (Score 1) 1367

by anmida (#26028807) Attached to: Time To Discuss Drug Prohibition?
Off-topic: Damn! I just used my last mod point! I would mod you Overrated just to prove that I really DON'T have a penis :p

Truthfully, I totally agree with you on the marijuana culture issue - at least within the sphere of universities, which is where most of us Slashdotters probably encounter it. However, it does depend on where you are - sometimes the people selling marijuana DO also sell harder drugs, too (my boyfriend worked in Hawaii for a while, the latter was the case there).

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