# P_Rog

Senior Members

52

1. ## Focusing Light - creating a hot zone

There are some larger lenses out there, but of course there is a payoff with focal distance. Looks like this idea is out, probably go with a resistance or RF furnace set up of some sort.
2. ## Focusing Light - creating a hot zone

Thanks for all the input so far...I'm still getting through my heat transfer class... It's for a heat treatment process, so I can't run a current through it. The heat treat has to be done in an inert environment, so the sample is enclosed with a He gas environment, which is why I was looking at the focused light. A laser is not in the budget. What about an RF induction setup or something similar?
3. ## Focusing Light - creating a hot zone

Hi all, I'm looking for some input on an experimental setup. I need to create a hot zone of about 800 centigrade and move a 2x2 inch bronze base through the hot zone. Ideally, the bronze base needs to be in a ambient temperature zone, then as soon as it hits the hot zone it heats up to the 800 or so centigrade. I initially thought of using a beam of light with a lens. I was thinking about using a 1000W halogen spotlight (8 inch diameter) and then use a lens to focus the light (the hot zone can be pretty small). Does anyone know any relationships of energy (temp) with respect to focal distance and diameter of lens? I was hoping to find a lens that would work for me based on that. Or any other suggestions for creating a hot zone? Thanks.
4. ## fusion by magnetic force

my thought process on this is that you have two particle accelerators, and im not sure how these work exactly and stuff, but two that accelerate to near the speed of light of a current or stream of protons. Lets say that at the end of the accelerator the two streams are parallel and a meter apart and then leave the accelerator. would the magnetic forces caused by the two particles force them to collide and ultimately fuse together?
5. ## fusion by magnetic force

If you could accelerate two beams of protons in the same direction near the speed of light would the magnetic force created by the particles overcome the elecric repulsion, allowing the particles to collide?
6. ## Diff EQ project help

I have a project assigned for my differential equations class and i was looking for some help on how to get started. I'm supposed to solve the initial value problem: y' = f(x,y) y(x(0)) = y(0) by taking into account the method of Picard, which we discussed in class. the problem is : y' = x*y y(0) = 1 i need to show that y(x) converges to the true solution. Our prof wants us to use a math software package which I don't have much experience in. I do know fortran, but don't know if that's any help. Im looking for a recommendation on what software to use, maybe some help on the code, or a general overview of how the problem should be handled. thanks.
7. ## nice little problem

if tan(pi/4 + a) = tan(pi/4) + tan(a) then it's just tan(pi/4 + a) I don't know if that is true, just a guess.
8. ## Why plane orbits

I was doing a little reading and looked and some pictures about planet orbits and other things. One thing they talked about is how they're all within one plane pretty much. I was wondering why this is, since gravity is holding it in, why wouldn't it be more spherical. If you look at dust clouds surrounding a star, they're planar, why isn't it a big sphere encompassing the planet?
9. ## White House cuts entire hubble budget, plans destruction

Apparently they plan to replace the hubble with the 'James Webb Space Telescope.' It won't be launched till 2011 though. This project is budgeted at $825 million, while the hubble fix up would be close to$2 billion. http://www.msnbc.msn.com/id/3217961/ I still think it's a mistake.
10. ## White House cuts entire hubble budget, plans destruction

http://www.msnbc.msn.com/id/6853009/ Now they've done it....
11. ## Acid/Base Problem

CH3COOH is a weak acid i believe, so it only partially dissociates. so turn 25 grams into moles, then divide by liters (1) to give you molarity, which is concentration. so... CH3OOH --> CH300- + H+ (Molarity)..........+X......+X M-X...................X........X X^2/(M-X) = Ka which is the equilibrium constant for this reaction, which should be given or you'll have to look up. X = [H+] and Molarity = [CH3OOH] pretty sure that's how it's done
12. ## Amount of energy in the universe

Since the first law of thermodynamics says that energy cannot be created or destroyed, only converted to one form or another....then the amount of energy when the universe was created would be total amount of energy available in the universe? Is there a way to know how much energy there was when the universe was created? Or maybe can one quantize the amount of energy say on earth and the atmosphere?
13. ## Car Stuff

correct, the torque converter is a clutch for the auto tranny except it uses fluid to transfer power. So when you're idling, only a small amount of fluid is being transferred.
14. ## I want to get ahead but...

you should be able to double up on your math courses by taking geometry and alg. 2 in the same year.
15. ## Why does burning Mg explode when...

I do remember this from one of your posts..... Not to be a bastard but you need to take chem 101...
16. ## Why does burning Mg explode when...

I do remember this from one of your posts..... Not to be a bastard but you need to take chem 101...
17. ## Why does burning Mg explode when...

when you pour water on Mg it is not combusting or burning, it is merely reacting chemically with the Mg. It is producing Mg(OH)2 plus H2.
18. ## Why does burning Mg explode when...

when you pour water on Mg it is not combusting or burning, it is merely reacting chemically with the Mg. It is producing Mg(OH)2 plus H2.
19. ## Magnetic field reversals, global warming & mutations.

i do remember watching some documentary about the switching of the poles and believe that it has been proven. I remember showing a computer model that predicted when the next switch would occur (it is continually switching). I think that it hasn't happened too many times in the history of the earth, so it is a very long process. I'm sure others can elaborate. Im not sure about the effects on the climate though.
20. ## Magnetic field reversals, global warming & mutations.

i do remember watching some documentary about the switching of the poles and believe that it has been proven. I remember showing a computer model that predicted when the next switch would occur (it is continually switching). I think that it hasn't happened too many times in the history of the earth, so it is a very long process. I'm sure others can elaborate. Im not sure about the effects on the climate though.
21. ## Global Warming

Can global warming be attributed to the large increases in processes in today's world that produce heat. Every day things such as transporation, A/C, creation of electricity, all produce heat. Can this be linked to global warming?
22. ## Waves as Particles

all things in motion have waves, called matter waves. light is is both waves and particles, called wave-particle duality, which einstein proved. the de Broglie relationship says that wavelenght= plank's contstant/mass*velocity. Since it is inversely proportional to the mass, the bigger the object, the smaller the wave. a baseball traveling at 60 mph has a wavelength of 1.6 x 10^-22 picometers. so small, it's not noticeable.
23. ## Derivative

d/dx[-.25x+2] = -.25
24. ## Ever catch spyware using Mozilla/Firefox?

I use IE and I run ad-aware about once a week and it always turns up about 10-20 spywares. I have norton anti virus and firewall, so what's the worse that spyware can do to my computer, saying that my firewall blocks out most of the big time things.
25. ## Recommed me a dvd - rw media pls!!

i use memorex and have no problems. Make sure you get the right kind, either DVD+R or DVD-R. Don't know how you can tell other than getting one of each and trying it out.
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