Physics, Astronomy & Cosmology / Re: Is there a substance where entropy decreases at higher temperature?« on: 17/12/2022 16:42:12 »
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I think you need to be careful about specifying whether you mean temperature or thermal energy.
One reasonable definition of energy is: T = ∂U/∂S (constant volume).might be a typing error. That's a perfectly good thermodynamic definition of temperature.
So the question becomes. For a given high and low temperatures (Thigh and Tlow), what is the optimal choice of ΔH and ΔS, such that the system is most stable between those to temperatures?Stability is not something you've decleared very well. I'm going to interpret the notion of "stability" as implying that the reaction would absorb (or release) as much heat as possible to counter a temperature change in the room.
But what I am most interested in at the moment, is just the math involved in figuring out how to maximize the ability of the solution to absorb/release energy over a desired temperature range.Let's minimise peoples disinterest and just do something for the simple situation.
I'll try and get it done but I'm off to the big city tomorrow and I know I won't be writing much here for at least a day.I'm really sorry but I'm not going to get this done any time soon.
This question is inspiredWell, it is quite a good idea.
ΔG = –RTln([Z]/[A])Could you clarify this please? I'm not sure what your ΔG is, is it actually ΔG° ? Are [Z] and [A] concentrations at equillibirum only? i.d.k.
Is this a known effect?Very much so, especially for flu. It is similar to heightened sensitivity to sound and light, especially when feverish.
Is there a known (or likely) mechanism?Apparently staying hydrated is a good way to limit it. Ibuprofen helps reduce inflamatory related symptoms, including the skin sensitivity. I found that acetaminophen does a nice job on headaches and fever, but not so helpful with the inflamation.
Is there anything I can do to limit it while recovering?
I came across another wrinkle: what about –1?Your general arguments after this are reasonable. However, I think it is again just a matter of simplicity and having a set of numbers that are useful for something. It is possible and useful to confine your attention to what people might call the counting numbers or the Natural Numbers, so we do. That doesn't mean that mathematicians have never considered generalising the idea of prime numbers and investigating properties like prime factorisation in a structure bigger or more abstract than just the positive counting numbers - they certainly have.
Is 2 really a prime number?Actually 2 is another number that has very unusual properties even though it is prime. It is often very useful and desirable for mathematicians to consider a subset of primes that doesn't include 2. They call this set the "odd primes" and several theorems are stated with reference to "odd primes" instead of just "the primes". Alternative terms exist for this set and it's quite common not to bother naming the subset and just write a result as holding "for all primes, p > 2".
The patterns formed on Chladni plates are a result of the properties of the plates themselves, and has nothing to do with the sand/salt/sugar/dust/etc. placed on top for visualization purposes. ..... The pattern that the nodes make is a function of the frequency of the vibration and the size/shape of the plate.Fully agree, acid test is that the pattern changes with frequency, so there is no memory effect.
Hi. I come up with extinguisher that can kill forest fires. I call it CO2 bomb.Fires need heat fuel and oxygen, you need to remove one to extinguish the fire. You cannot reliably remove the oxygen from a fire for a sustained period, nor the fuel in any reasonable scenario using fire suppressants etc, so you need to remove the heat. Extinguishing the fire may remove the heat from a small fire long enough to cool the fire but a large fire needs cooling down a great deal, this is why the fire brigade spend long periods dampening fires and raking through material piles.
Looks like American-football ball, but bigger. inside is lots of liquid CO2.
Drop one in the forest fire. Valves will open and release huge amount of liquid CO2, which will become gas.
Alan, don't you work with MRIs? I assume you know what happens when a magnet quenches...Indeed. But suffocation incidents are usually associated with the loading and cooling process, not a subsequent quench. We have exhaust stacks to vent quench gas safely once the magnet is assembled.
If you want light energy......Heat a piece of quicklime with your oxyhydrogen torch.
A great way to reduce co2 or methane if you believe both to be the cause is to shoot animals, people will even pay you for the privilege.We fish and shoot already.
What's 0 to the power of 0?This is actually a very good question and it's something that isn't easily resolved.