Recent content by uncanny_man

Do you have any chemistry background? Because the easiest way to think of the Fermi level is as your highest occupied orbital. The major difference is that in a crystal structure, your discrete atomic or molecular orbitals blend together into bands of energy levels (so it isn't a Highest...

I would be surprised if the current ICBM designs weren't still classified...

In terms of a p-n semiconductor laser, I would agree with you. However, what about a solid state laser (probably optically pumped...)? The low fermi level likely won't help the efficiency, but once the population of electrons is inverted, that direct gap should still lead to lazing as the...

This is actually where Einstein's famous E=mc^2 equation came from. For the longest time, physicists were puzzled because nuclear fission reactions seemed to slightly violate the law of conservation of mass. If this small amount of destroyed matter is converted to energy with the above...

I haven't looked up your papers yet, but if the solvent is water, the go to method for determining the purity is good old resistivity. Ultra pure deionized water has a resistivity of 18.2 mega-ohms, and that resistance drops extremely fast if there are any ions present.

Now that's an interesting idea. I had been thinking in terms of absorption, I hadn't been thinking in terms of emission. It might actually be interesting as a solid state laser active medium...

Thats a tough call because, unlike most metallic band diagrams, there is a largish (around 1.6 eV) direct band gap above the the fermi level, valence states, and some of the p-band conduction states. As an intrinsic crystal, it really does more closely resemble the band diagram for a highly...

Ah! The wafer spammers have followed me here!

Hello. "Hypothetically" let's say that I have a material that intrinsically behaves like a highly degenerate p-type direct gap semiconductor (significant p-orbital contribution to the DOS at and above the fermi level). Can anyone think of what in the world such a material may be useful for...

Oh yeah, you could only really separate out the light and select a wavelength if all of the wavelengths were present in the first place. Unfortunately, for a good intense beam of the full spectrum of x-rays, that pretty much leaves you using a synchrotron for your light source (from...

Absolutely. This is the approach often used in spectrophotometers: you break the light up into a rainbow and use a narrow slit to select a very specific wavelength range. That said, for a spectrophotometer you don't need to worry about the efficiency (obviously most of your light's energy is...

Actually, you kind of have that backwards. You compress a gas, which causes it to heat up in accordance with your favorite gas law (I like PV=nRT). If you're trying to chill something, you obviously perform this process on an the other side of an insulated barrier from what you want chilled...

Now obviously you aren't going to be able to decrease the wavelength (higher energy) with something like this, but x-rays are on the right wavelength for atomic lattices in a crystal to act as a diffraction grating. In that case, might it be possible to tune the wavelength using a crystal as a...

Theoretical, but for a very specific hypothetical application. I'm thinking of making a kind of detector in which sections of a thermoelectric array are functionalized to heat under certain conditions, others are not. In this case, it is essential to maximize temperature change for a small...

I first learned about them with this article, I thought it was pretty well written: http://home.howstuffworks.com/ac.htm