/sci/ - Science & Math

[Anonymous No.6938946]

Just got my take-home exam in my most difficult course back. Assigned last friday at 5:30 pm, was due monday before 9 am. It spanned 10 chapters and took me 12 and a half hours to finish (and we got to choose our own problems). I score 100% and I'm fucking amped, because it likely turned my B into an A and I will (knock on wood) be exempt from taking the final exam. Celebrating with beer and pork chops. Ask me anything.

[Anonymous No.6938952]

>>6938946
what kind of beer?

[Anonymous No.6938955]

>>6938946
What's it like going to a garbage school that gives take home exams?

[Anonymous No.6938956]

>>6938952
blue moon because it's chill as fuck

[Anonymous No.6938962]

>>6938955
we were supposed to have 3 exams but only got to 2 before this and couldnt go into dead week which started monday (which is why the professor made the exam due at 9 am). but I go to Purdue. pretty good program for what I'm studying. the only other time I had a take home exam was a take home final for a lab course. but I will say that this exam sure as shit wasn't easy

[Anonymous No.6939000]

>>6938962
>state school
>good

[Anonymous No.6939003]

>>6938946
>Ask me anything.
What's it like to have a personal blog that also functions as an imageboard for Cambodian cartoons?

[Anonymous No.6939006]

>>6939003
hey man I'm just hype as fuck for doing well in my hardest course and having my hard work pay off. And if anyone wants to ask me questions about anything, I'm like a reservoir of information. I'm a 5th year student (don't give me shit I switched majors) so I can give out more info than just first/second year math/phys stuff.

[Anonymous No.6939054]

More specifically, yall niggas can ask me anything on the subjects of nuclear engineering, radiation, or fusion power. I'm starting to get a little buzzed so you'll get my honest answers

[Anonymous No.6939176]

Come on you fuckers, don't you want to learn something new? Ask me some shit, I'm bored as fuck and answering questions is always good review/reinforcement for finals coming up.

[Anonymous No.6939189]

>>6939006

>OP is an engineer
>at Purdue
>the hardest course's final question was something like:

>"Calculate the flux of the vector field 3xyi+6x^2yzj-3yz^2k through the unit sphere"

>mfw it took OP 12.5 hours to solve

[Anonymous No.6939201]

>>6939189
it's a graduate level course so it's not some trivial /sci/ tier problem that you could find on yahoo answers

[Anonymous No.6939206]

>>6939201

>graduate level intensive study of differential equations

[Anonymous No.6939207]

>>6939201
my graduate level exams are definitely easier than my undergrad ones were.

Why aren't you working on your research?

[Anonymous No.6939213]

>>6939207
I don't do research, I'm still in undergrad, this course is an elective to fill in space because I'm behind in some areas and ahead in others for my plan of study, but I didn't take it as an easy elective, it's a tough course but I really respect the professor and the subject is something I'd like to pursue further, either in grad school or industry

[Anonymous No.6939220]

>>6939054
What sort of equations do you usually use to model a fusion plasma?

-Do you use a "multiple fluid" model, like, for each type of charged particle in the plasma (electron, deuterium, tritium, alpha), you have a set of navier-stokes coupled with maxwell's equations?
-Then what equation do you use for the actual fusion process? Is it just some rate like "if densities and temps of the D and T plasmas are ..., then rate of fusion is ..."? Would that rate be determined empirically, or is their theoretical work on this?
-Do you ever need to take quantum effects into account (e.g. QED formulas)? What about relativistic effects? Do you have to use some relativistic analogue of Navier-stokes?
-How exactly was it determined that the stellarator is the "optimal" shape for fusion? What does that mean, in quantitative terms?

Sorry for all the questions. I hear that modelling fusion is very difficult.

[Anonymous No.6939261]

>>6939220
>-How exactly was it determined that the stellarator is the "optimal" shape for fusion? What does that mean, in quantitative terms?
first of all, TYBG, nobody on /sci/ ever knows shit about fusion, let alone stellarators. it's not that they're the best shape, but they exhibit some really great plasma phys and topology. for one, they aren't subject to the nasty E x B drift that tokamaks are subject to, and they are inherently steady state devices, whilst tokamaks are inherently pulsed devices. but the plasma phys and transport theories are much more difficult than in tokamaks due to the helical winding of external coils.

as for modeling, I can only say that there are 3 different ways of looking at it. my professor always likes to say that plasma wears 3 different hats. a fluids hat (MHD), a particle hat (treatment of ions/electrons as particles), and a wave hat (treatment of ions/electrons as waves). they all have purposes/advantages. MHD will help determine bulk plasma behavior and plasma instabilities, particle treatment can be used to determine banana orbits and diffusion rates (which can be useful in determining bootstrap current), and wave nature can be very useful in determining the coupling of wave/microwave systems for plasma heating/current drive. relativistic effects aren't that significant, at least for ions (with velocities on the order of 10^5 m/s) whereas electrons may have velocities on the order of 10^7 m/s). there are of course momentum equations similar to navier stokes, just solved in terms of plasma denisty and such, not in the same respect as regular fluids.

[Anonymous No.6939267]

>>6939261
quantum effects aren't a huge concern, but MHD is a big deal, even when not dealing with plasmas, for example in the blanket region of a D-T reactor, if you were to use a liquid metal coolant such as Li, you would need to take MHD effects into account, because it would take significantly more power to pump liquid litium than helium, even if both were the same density, due to the fact that liquid lithium has charge movement when pumped, which is current, which generates its own magnetic field, and can induce its own electric field, ie EMF and requires additional power to pump.

[Anonymous No.6939269]

>>6938946
Did you take the exam for knowledge or for the grade?

[Anonymous No.6939288]

>>6939269
I'm not sure what you mean. Of course I wanted to get a good grade, but I couldn't exactly do that without adequate knowledge of the material, especially given that our professor takes off points when you don't have ideas that logically follow one another. so it's pretty difficult to bullshit your way through a homework assignment/exam. it was mostly due to wanting to not let the professor down, because I have great respect for him and admire the things that he's done, and partially because I want to prove to myself that I've learned enough in the course to understand and solve the problems, because it's one of the fields I'd like to work in when I graduate.

[Anonymous No.6939322]

>>6939206
not everyone on /sci/ is a sperg math major

[Anonymous No.6939386]

>>6939322
>dubs
>somehow still don't believe 100% of /sci/ isn't sperg math majors