Recent content by Chemmjr18

Pretty great thread. Thanks!

Negative Kelvin http://science.sciencemag.org/content/339/6115/52. How is this possible? If anyone could help me understand this I'd appreciate it.

Is there a way to look at mass spectra and determine the method of ionization? I.e., whether it's electrospray, FAB, MALDI, etc.

Ok. I was informed by both a professor and someone on this forum that If the concentration of dopant remains exactly the same in the crystal, and we just increase the size the crystal, emission lifetimes will not be affected. If the concentration changes, however, it will. I appreciate all the...

Here https://www.physicsforums.com/threads/does-the-size-of-a-crystal-used-for-a-laser-affect-lifetime.930443/#post-5876944

This what is was thinking. However, I was recently told that changing the crystal size would affect the lifetime. When I get a chance I'll link the thread. Thanks for the response.

I meant "first-order decay lifetime" as the intrinsic lifetime of the radioactive decay.

No, it's not. You're just perceiving as a strawman. If it's a misunderstanding, then it's a misunderstanding and call it that. How are detection limits not related to our ability to measure? (this is a genuine question) I said the sample size would impact what we observe--but right after that I...

Ok. There are limits to how much of something we can detect. The detection limit is "the concentration of analyte that gives a signal equal to three times the standard deviation of signal from a blank". If the analyte (in this case whatever is decaying) isn't producing a significant enough...

Don't quote me on this, but yes, I do believe the there is a size dependence of the material on the observed radioactive decay. Isn't there a size dependence on anything we use quantitative analysis on? I believe this is called the lower limit of quantitation. But just because we can't detect it...

Half-lives are constant, but different for different species, of course (It may not be exactly independent of temperature though). The half-life is inversely proportional to the rate constant. Thus, the rate constant is constant. I just assumed the since they were they were both first-order...

Thanks! Especially for the article. I can't read it right now since I'm not on campus but I'll make sure to. Just to make sure I'm understanding your answer: If the concentration of dopant remains exactly the same in the crystal, and we just increase the size the crystal, we can expect emission...

I thought it would only effect the quantum yield. How would any of these things impact the amount time it takes for a photon to be emitted from an long-lived excited state a short-lived lesser excited state? The lifetime is inversely proportional to the rate constant. I've heard of the rate...

Say that I have a neodymium doped yttrium aluminum Garnet (Nd:YAG) laser crystal rod. If I'm using this crystal in a laser, will the size of the crystal affect any characteristics of the laser itself. That is, will a laser containing a 4-by-7 mm Nd:YAG rod operate differently than a laser...

Hmmm. I see where you all are coming from. Perhaps it's due to my poor understanding/wording. Say that I have a neodymium doped yttrium aluminum Garnet (Nd:YAG) laser crystal rod. If I'm using this crystal in a laser, will the size of the crystal affect any characteristics of the laser itself...