Would I be wrong to simplify and say a PID loop is more or less an if this, then that algorithm? I don't do industrial process control programming (but am thinking about it) I do have to manipulate user inputs via the hmi and I understand coding and work with paid and open source process control programs. (looking for a career change). Thanks

It can, yes.

It depends on the nuclide, and the energy regime. Here are some examples.

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Not really. The uranium atom would be in the ground state. Higher temperature would increase the KE of the U235 atom but it would also increase the average KE of neutrons available. And as mentioned elsewhere, higher KE neutrons have less probability of being absorbed.

So for cores designed for thermal neutrons they have a “negative temperature coefficient” or if the reactor gets hotter, fission rate decreases, bringing the temp back down. This is a nice feature to keep the reactor controlled, but it wont prevent a meltdown outright.

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No, that has more to do with the material choices in the construction of the reactor. The moderator (the medium used to slow the neutrons to the desirable range for continued absorption but the fuel for additional fission) in different reactor designs isn’t always water. As I understand it, it’s the moderator which carries the temperature coefficient attribute. Water is negative, graphite (like in Chernobyl’s RBMK style reactor) is a positive temperature coefficient.

With a water-moderated reactor: temperature goes up -> total fission goes down -> power goes down (all else being kept equal). Which makes temperature come down. Which makes power go back up. This results in a sort of sine-wave oscillation of the reactor’s power level for a short time until other elements of operation come into play.

Graphite moderated reactor: temperature goes up -> total fission goes up -> power goes up. Which makes temperature go up. And the cycle repeats. This was a key oversight in design for what happened in Chernobyl, and why the choice of a water moderator helps to create a reactor design which is inherently stable.

Edit: Doppler broadening is more about why it’s preferable to operate with the fuel at a higher temperature from an efficiency standpoint in terms of using the available neutron flux to create sustained chain reactions.

Checkout u/mtv2002 reply higher in the post. Farms might have common personnel, equipment, visitors,etc. after all its a business. So many ways to spread the virus through various surfaces. Not a virologist, but air transmission might be possible.

Surface tension is the main driver of the movement of water across fabrics.

Some materials, like cotton, are very porous, and have low "contact angle", a property which governs the wettability (yes, a real word) of the material. This encourages the ABsorption of water, both along the length of the fibers, and into every nook and cranny of a given fiber as well. This is what makes cotton so absorbent, but it's also what makes it such a terrible fabric to have against your skin. It TRAPS moisture. Once the water gets into those little nooks and crannies, surface tension keeps it there, and very little of the water is exposed to the air, so it dries very slowly.

Other materials, like nylon, are inherently non-porous, so they can't ABsorb water into the individual fibers. They can, however, still ADsorb (also a real word) water along the length of the fibers. This means that the water is just sitting in top of the fiber, fully exposed to the air, allowing it to evaporate quickly. This tends to be true of most of the synthetic fibers, which is why they dry so quickly once they DO get wet. Getting them wet in the first place, however, is hard, because they tend to have higher contact angles, which makes it harder for water to get a hold, and some of them, like nylon, can be woven so tightly that they almost become hydrophobic. This is why synthetic clothes dry really fast, but also feel nasty against your skin when you sweat - the sweat doesn't get picked up off your skin, so you just feel the sensation of water on your skin.

Now take wool. A truly impressive fiber. It's not really porous in and of itself, so it doesn't absorb very much, but it has a lower contact angle and greater ability to ADsorb water, which makes it much better and pulling water off your skin. This is why all of the finest expedition, outdoor, and sports clothes are made of merino wool. It's naturally anti-bacterial, and it's proficiency at wicking away water, and then letting it evaporate, makes it very thermo-regulating. It keeps you warm in the winter, and cool in the summer.

Ahh okay and another thing I hear being mentioned is it being SPREAD to another farm? How is it being spread if the birds are stationary.

Your logic is right. But note farms kill their birds quickly after the flu is detected, infected or healthy. They cannot test all birds, so there could potentially be some birds that got the virus before and survived, or inmune ones. But because of the risk involved all are killed.
So there is little time to actually have survivors.

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Absorption and transpiration are two different processes, though. Cotton IS very good at absorbing water, which is why it sucks so much to wear it. When something Absorbs a fluid, it takes it into itself. Cotton wicks water into its structure - - like, into the actual individual strands of thread, where air and wind can't get to it, to evaporate it.

If you take something like wool, on the other hand, the hairs themselves do not actually absorb water in the same way that cotton does. This is wonderful, because they simply pull the water ALONG the hairs via surface tension and capillary forces, rather than pulling the water INTO itself. This exposes the water to air on the other side of the fabric, allowing it to evaporate.

The same is true of polyester, which is why poly is the go-to cheap sports fabric, and wool is the king of sports and sweating fabric when you don't need the structural properties of poly.

Try it for yourself. Wear a pair of merino wool socks for a few weeks, then go back to cotton. It feels like you're standing in a puddle by comparison. The cotton simply traps moisture against your skin.

Good meme 10/10.

Actually, it's not patronising. It feels good to know that Feynman and Co said those things.

I listened to a few detailed podcasts explaining the maths of QM, but I haven't done anything myself.

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> QM
> more intuitive explanation

Choose one

;)

Sorry, just adding some drama to the question, or arguably a realistic perspective, regarding your more philosphical statements on fundamentals of QM or postulates, or understanding goals. I'd add more to try to answer your questions if I weren't under-qualified from the get go, combined with forgetting entirely too much of my education.

What I can comment with some relevance on: continue your pursuit of better understanding, but alter your expectations, because intuition is usually a false friend with QM! E.g., the fun, if not overused, electron spin meme

Also adding the first paragraph from the introduction in an intro QM for undergrad physics students book (Introduction to Quantum Mechanics: 2nd Ed. by David Griffiths): > Unlike Newton's mechanics, or Maxwell's electrodynamics, or Einstein's relativity, quantum theory was not created - or even definitively packaged - by one individual, and it retains to this day some of the scars of its exhilarating but traumatic youth. There is no general consensus as to what its fundamental principles are, how it should be taught, or what it really "means." Every competent physicist can "do" quantum mechanics, but the stories we tell ourselves about what we are doing are as various as the tales of Scheherazade, and almost as implausible. Niels Bohr said, "If you are not confused by quantum physics then you haven't really understood it"; Richard Feynman remarked, "I think I can safely say that nobody understands quantum mechanics."

Physics, including QM, is a lot of explaining these "why" questions you ask via math. My very unsatisfying and generalized - possibly patronizing (if so, sorry, that's not the intent) - recommendation is that if you want to dive deeper and have a more satisfying or stable foundation for your understanding, look into more of the accompanying math!

Happy exploring!

^(Thanks, also, for a reminder to revisit my own study :)^)

I'm confused, the survivors of any avian four would not have any virus. They would, actually, have immunity to the avian flu and thus be more safe than those who didn't have any protection to begin with? Although this can't be passed onto new members, aren't they "golden eggs" (no pun intended) because they will survive even if another virus spreads through the farm? Explain

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The obvious application is that if you want to design a control circuit for something that's able to move around and you want to be able to tell it to remain in a specific place, you use a PID controller to actuate whatever it uses to move itself. PID stands for "proportional, integral, derivative".

In the case of trying to maintain the same position, one part of the decision of how hard to try to move in a particular direction would be how far away you are from your set point at that instant. That's your proportional control. If you're really far away, you probably want to push pretty hard to get back so that you can spend more time at your set point. Another part of the decision of how hard to try to move would be how long you have been away from your set point, and how far you were over that time (you probably want to push harder to get back to your set point if you've been very far away for a very long time, but even if you've gotten very close, if you've been away from that set point for a really long time, you need to push a tiny bit harder to get back exactly where you want to be). That's the integral control. And, of course, the derivative control is obvious: if you're away from your set point and your velocity is still in a direction away from your set point, you definitely need to push harder back towards your set point.

The integral component here is reliant on absement.

I'm not sure i get what the Schrodinger equation solutions for the hydrogen atom have to do with the quantum nature of the electric charge.

I understand the electron shells, but how does that relate to the electric field being quantized?