That is a really good question. I'm a materials engineer, and we don't have to take OChem, even if we specialize in polymers.
Our EEs actually just take a semester of gen chem. I think the same applies to some of the others like Mechanical, Aero, and Construction engineering. I haven't taken any electronics courses but I can't really see where that would come in handy for you. So I second your motion of shenanigans.
100 C is boiling water. If steel melted at that temperature my stove would be covered in a puddle of slag right now.
Huh?
I know steel melts at significantly higher temperatures. I specified polymer composites and did not say anything about melting. You may be able to try out the property with boiling water, though. PVC and PET both have Tgs between room temperature and 100 C so they should feel noticeably softer (because they "transform" to a rubbery state) if you hold them in a pat of boiling water for a while.
If you remain unconvinced that polymers can have rather limited operational temperature ranges, just stick your hand in, too. I guarantee you will get some thermal degradation in very short order.
I really don't need to know bad enough for you to get in trouble about it. I'm actually a materials engineering major in Ames and I'm specializing in polymers and ceramics (metals too at the moment, but we'll see how that goes) so I was kind of interested in specialized applications like this, and especially if everything I'm being told is wrong.
I'm still having trouble believing a polymer that holds up to more than a thousand degrees Celsius, but it wouldn't be the first time something slipped me by. I would think a polymer with any kind of strength at 2000-3000 C would be one of the first things we would hear about because there would just be so many applications (the first thing I though of when I heard you say that was that they could definitely use fan blades for the jet turbines with those properties in polymers - ceramics are weak in tension and refractory metals that would lend themselves to this application are ungodly expensive).
I know that some allotropes of carbon will do go that hot (like graphite and diamond), but carbon chains and networks with hydrogen and other functional groups tend not to have the greatest bond strength and some ability to move past each other, reducing melting point below those levels. My old Callister book even gives a melting temperature of 640 C for aramid fibers. These are things like Kevlar and are usually what people mean when they say "carbon fiber". I've seen people use a process like the one you described to lay up composite panels, they refer to it as "prepreg" since the resin is pre-impregnated in the fibers. Sure is a lot easier than laying them up by hand. But I'm pretty sure they never took them above 500 except to see when stuff would burn off in a TGA analysis or something. With the right material, you could probably mitigate thermal effects by drawing it away with the right thermal conductivity, but I would bet money you were using a ceramic to take the brunt of the heat if it got as hot as you said. I could see you cooking with an aramid composite, but much hotter and you'd essentially be able to, for example, melt and pour aluminum in a plastic bowl. I just can't see that happening right now.
Anyhow, I do find this pretty interesting now and I'll probably look into it a little more. If you have any suggestions where to start (again, don't risk any trouble, it's really not worth your former employer coming down on your ass) I would appreciate it but otherwise I thank you for the engaging discussion.
Oh, and in case you're worried about sending the thread off topic with a reply, my gmail's csents.
> 100-200 deg. C
May be your missing some "0" in there.
The High Temperature Carbon fiber reinforced polymers I was working with a NASA Ames were good up 2500 to 3000 deg. C. Their thermal conductivities were over 1700 WmK (Watts per Meter Kelvin where Steel is around 60, Aluminum 200 & Copper 400) These were used for the leading tips of super sonic aircraft.
I even experimented and made a light weight non-metallic frying pan just for fun using the stuff.
My interest was in using these Carbon fibers to cool CPU chips, so I never took them any near those temperatures in my application but needed the thermal conductivities.
The price of the material wasn't actually that expensive either when you started buying in bulk. Problem now is these fibers are only made for Aerospace in very small runs and done on defense contractor budgets.
Can you tell me which material this is? I looked on the NASA Ames website and it seems the project you are describing actually used a ceramic matrix rather than a polymer, which would make a lot more sense to me. The best high-temperature resin I am familiar with is Bisphenol E cyanate ester (BECy), which has a Tg of around 225 if I am remembering correctly. Polymers, at least the definition I am familiar with, just simply don't work around the temperatures you quoted.
Most polymer composites (which include carbon fiber materials) have a Tg (glass transition temperature) around 100-200 deg. C. At this temperature the polymer changes from a glassy state to a rubbery state (the opposite can be observed if you cool a rubber band down far enough). Some can be higher but not much. They also tend to degrade and oxidize around the 400-600 deg. C range. Long story short: polymer composites are great for a lot of things, but high-temperature applications definitely do not fall into that category.
I do agree with a previous post I saw which suggests engineered ceramics. Ceramics are very good refractory materials, as they retain much more strength and oxidation resistance at high temperatures than steel, or for that matter, nearly all metals. They're also most likely going to be much, much cheaper than any metal engineered for this application. Steel doesn't fit the bill yet, and it would probably take a lot of research to figure out new heat-treatment methods to get it there. Some more exotic metals like some in the platinum group might look attractive until you see the price tag.
Actually, all ferromagnetic materials have a point called the Curie temperature where they lose said ferromagnetic properties. It's pretty high for iron (Wikipedia cites 768 deg. C) but maybe if you could cycle up the beam to a high enough temperature using physical contact with the walls at first before actually turning on the magnets, this would probably keep the machine from ripping itself apart.
Mind you, I have no idea if this goes completely against how the machine works or anything, and there are a lot of other problems with steel that have been mentioned already, but this could be a workaround.
I remember playing Sim City way back in elementary school on some obscenely old Mac at the library. At that point it was a toy, I would build a police and fire station, maybe put up a stadium and some power plants or whatever I thought would look cool at the time, and then ran out of money.
It blew my mind when I finally realized that there was more to it; you could improve your situation and all and actually play it like a game. The fact that it worked on both of those levels probably made it the game I had played the longest/most out of any to date. Although I do still break out the Kirby once in a while just to make sure I can still destroy King Dedede.
The trouble with epoxy potting is getting the heat out of the board. You need to leave the thermally conductive parts outside of the potting so that you can remove the heat. The epoxy itself isn't thermally conductive enough to get processor heat out, even on a processor with passive cooling.
Coming from a materials engineering background, this was my first thought about the question. A material which is very thermally conducting while also electrically insulating sounds like a pretty tall order to me. The reason is that one of the primary methods of heat transfer is through transferring excited electrons.
The two others are phonon transmission through the lattice and radiation. A lot of things which block electrons also block phonon movement (basically heat transfer through vibration) and I'm guessing radiant heat is not going to be sufficient. The one material I do know of which has high thermal conductivity and low electrical conductivity is diamond. It's kind of an oddball, though. I'd be interested to know if there are other, more common materials that would suit this application.
Then there's also the CTE mismatch issue mentioned later in the thread. Whether you design the specs for the high-heat state while it's in use or the cool state when it's off, the other state is going to put a lot of thermal strain on your circuit board components. I'd imagine you could solve some of these problems, but I doubt you're going to be able to take care of them all.
I seriously doubt that humans were holding on to each other for lifetimes before the dawn of religions. After all, the whole idea of staying together forever and ever is all taken from a few books that people wrote hundreds of years ago.
Let's say that we go 10,000 years back.
Did you not see 10,000 B.C.? Eh, can't really blame you.
I guess technically that was 12,000 years back, but it seemed to go on at least long enough to fit into your timeframe.
And before someone goes around throwing the hindenburg in everyone's faces, keep in mind that it was painted with rocket fuel, and that more than half the people on board survived the crash. The same cannot be said for your average airplane.
Any plans for what to do as they convert to wind power? Or will power plants be kept as a source of heat with electricity as a brpãduct?
I think they use the steam to power those giant fans you see everywhere. This is where wind comes from, and it's eventually reclaimed by wind turbines. Unfortunately, the wind is being overfarmed, and we need to build more nice big coal power plants to ensure it remains a sustainable source of power.
Actually, it seems to me like the MPAA's been taking the saner approach all along.
Every time I hear about the RIAA, they're suing someone new or getting another judgment handed down. Every time I hear about the MPAA, they're trying something new - online services like streaming shows and the whole Netflix thing, "educational" (threatening) letters, or a summer which, in my opinion, has been filled with an unreasonably high number of decent films.
I'm not saying they've gotten things perfect, but it at least looks like they're trying, and it would be nice if people recognize that and throw a noticeable amount of support their way in response. That way, they can see that the evil haX0rs aren't out to get them and the public really is willing to work with them. Because the alternative is that they recognize the RIAA's "bite the hand that feeds you" campaign is turning more of a profit through settlements and go that route. Maybe I've missed news stories where the MPAA does the same thing, but for the sake of not moving to Canada I'd like to think not. It's cold up there. And filled with Canadians.
The flipside of that, of course, is to let the RIAA know how we feel about their strategy. For example, I recently got fed up with them and opened an e-music account. I know there are other sites but I'm a little hooked on this one, you know how it is. It seems to have everything we want straight from a wish list (reasonably priced quality songs without DRM and no RIAA). Like I've seen a lot with similar posts, I missed some of the bigger name bands and it's a little harder to find what I want, but I've also heard that if that sort of thing deters you they take your geek license on the spot.
So yeah, I guess my point here is look around, and use the language they under$tand to tell the *AAs what you like (or don't). That's the only way things will really get better. If you only hide behind "extra features" of illegal services to justify breaking the law, well, sorry to say but they probably are justified in suing that attitude out of you. But if you are willing to support those features, they might actually get implemented. Because, in the immortal words of Peter Griffin, "Black or white, the only color that really matters is green." And I'll continue to watch Family Guy as long as they don't sue me for the $0.02 of whatever I just stole there.
Innocent infringement : defendant was not aware of any copyright infringement, and upon information and belief some or all of the copies which she downloaded did not bear copyright notice.
This looks very weird - when people rip CDs and DVDs, they rarely (if ever) attach any copyright notice to the resulting mp3 and avi files... Would it mean, that because the copyright notice has been removed (it was on the CD case for sure, or the load screen of the DVD), then you don't know you are infringing? As much as I applaud the rest of the complaints, this is just silly. On the internet it is mostly: "everything is copyrighted except if it's explicitly noted", not the other way around...
On the other hand, if it gets accepted, then everyone is pretty innocent from this point on... Would be fun.:)
True, but since everyone involved in this matter seems to so enjoy analogies...
Say someone anonymously donates a DVD (or a CD) to a library. It gets rented out to anyone who cares to watch/listen to it gets to, free of charge. Now one day one of the *AAs comes in and says the disc was illegally produced. They have no way of knowing or finding out who produced the copy, so instead they're going to obtain the library's records to sue everyone who touched the thing as well as the library itself.
Maybe the original crook even stripped copy protection somehow and the *AA's now suing for more on the basis that the renters "could" have made the content available online. If not that, they certainly could have shared it with their friends. And they almost definitely viewed it without the license to do so. However, just like the typical targets of online file-sharing stings and lawsuits, they most likely had no idea that what they were doing was wrong.
People don't question free goods/bargains. Don't believe it? How many people wonder even for a second how they can get a decent shirt for a buck or a pair of five/ten dollar shoes? That kind of ignorance leads companies to act illegally/immorally for a competitive advantage anywhere they can get away with it. This scenario could most likely even play out with unreleased material and no one would care until the legal shit went down.
Are these people guilty under some interpretation of the law? I would almost guarantee that the lawyers will spin it that way. Did they really do anything wrong? I'm inclined to say hell no. And some exorbitant six-figure fine or several thousand dollar settlement seems unreasonable to me.
Of course ignorance shouldn't be excused, but if dirty water starts coming in, it doesn't make sense to beat the people bringing it to you. If you want the problem fixed you go after the person who's mucking things up upstream, no matter how hard that may be. Otherwise you deal with it.
Again, I apologize for the analogies, it seems to be the native language of these forums.
Maybe the most important point, at what cost? how rare/expensive is that new material? If is very, maybe the main use would be not for our normal lifes, but maybe for i.e. space probes.
They already use materials like this in space probes - you put a hot radioactive isotope at the end of one of those long rods and thermoelectric generators through the rod - they're ridiculously inefficient right now, but there are no moving parts they're less likely to break down, which is more important on long, unmanned space missions. I'm a materials engineering major and one of the things we were told in our intro class was that if anyone ever figures out a way to make this type of material more efficient, they will make bank.
Theoretically, you can pump them up to a higher efficiency than modern generators and keep the moving parts out, eliminating nearly all of the maintenance costs in power production. So I find this very exciting, although a little disappointing that there's one less target to go after now.
Slashdot Mirror
Swearing alone would take up at least half of the filter.
And the other half is someone just yelling, "VEETO!"
Our EEs actually just take a semester of gen chem. I think the same applies to some of the others like Mechanical, Aero, and Construction engineering. I haven't taken any electronics courses but I can't really see where that would come in handy for you. So I second your motion of shenanigans.
Uh, yeah, you missed a zero.
100 C is boiling water. If steel melted at that temperature my stove would be covered in a puddle of slag right now.
Huh?
I know steel melts at significantly higher temperatures. I specified polymer composites and did not say anything about melting. You may be able to try out the property with boiling water, though. PVC and PET both have Tgs between room temperature and 100 C so they should feel noticeably softer (because they "transform" to a rubbery state) if you hold them in a pat of boiling water for a while.
If you remain unconvinced that polymers can have rather limited operational temperature ranges, just stick your hand in, too. I guarantee you will get some thermal degradation in very short order.
I really don't need to know bad enough for you to get in trouble about it. I'm actually a materials engineering major in Ames and I'm specializing in polymers and ceramics (metals too at the moment, but we'll see how that goes) so I was kind of interested in specialized applications like this, and especially if everything I'm being told is wrong.
I'm still having trouble believing a polymer that holds up to more than a thousand degrees Celsius, but it wouldn't be the first time something slipped me by. I would think a polymer with any kind of strength at 2000-3000 C would be one of the first things we would hear about because there would just be so many applications (the first thing I though of when I heard you say that was that they could definitely use fan blades for the jet turbines with those properties in polymers - ceramics are weak in tension and refractory metals that would lend themselves to this application are ungodly expensive).
I know that some allotropes of carbon will do go that hot (like graphite and diamond), but carbon chains and networks with hydrogen and other functional groups tend not to have the greatest bond strength and some ability to move past each other, reducing melting point below those levels. My old Callister book even gives a melting temperature of 640 C for aramid fibers. These are things like Kevlar and are usually what people mean when they say "carbon fiber". I've seen people use a process like the one you described to lay up composite panels, they refer to it as "prepreg" since the resin is pre-impregnated in the fibers. Sure is a lot easier than laying them up by hand. But I'm pretty sure they never took them above 500 except to see when stuff would burn off in a TGA analysis or something. With the right material, you could probably mitigate thermal effects by drawing it away with the right thermal conductivity, but I would bet money you were using a ceramic to take the brunt of the heat if it got as hot as you said. I could see you cooking with an aramid composite, but much hotter and you'd essentially be able to, for example, melt and pour aluminum in a plastic bowl. I just can't see that happening right now.
Anyhow, I do find this pretty interesting now and I'll probably look into it a little more. If you have any suggestions where to start (again, don't risk any trouble, it's really not worth your former employer coming down on your ass) I would appreciate it but otherwise I thank you for the engaging discussion.
Oh, and in case you're worried about sending the thread off topic with a reply, my gmail's csents.
> 100-200 deg. C May be your missing some "0" in there.
The High Temperature Carbon fiber reinforced polymers I was working with a NASA Ames were good up 2500 to 3000 deg. C. Their thermal conductivities were over 1700 WmK (Watts per Meter Kelvin where Steel is around 60, Aluminum 200 & Copper 400) These were used for the leading tips of super sonic aircraft.
I even experimented and made a light weight non-metallic frying pan just for fun using the stuff.
My interest was in using these Carbon fibers to cool CPU chips, so I never took them any near those temperatures in my application but needed the thermal conductivities.
The price of the material wasn't actually that expensive either when you started buying in bulk. Problem now is these fibers are only made for Aerospace in very small runs and done on defense contractor budgets.
Can you tell me which material this is? I looked on the NASA Ames website and it seems the project you are describing actually used a ceramic matrix rather than a polymer, which would make a lot more sense to me. The best high-temperature resin I am familiar with is Bisphenol E cyanate ester (BECy), which has a Tg of around 225 if I am remembering correctly. Polymers, at least the definition I am familiar with, just simply don't work around the temperatures you quoted.
I do agree with a previous post I saw which suggests engineered ceramics. Ceramics are very good refractory materials, as they retain much more strength and oxidation resistance at high temperatures than steel, or for that matter, nearly all metals. They're also most likely going to be much, much cheaper than any metal engineered for this application. Steel doesn't fit the bill yet, and it would probably take a lot of research to figure out new heat-treatment methods to get it there. Some more exotic metals like some in the platinum group might look attractive until you see the price tag.
Mind you, I have no idea if this goes completely against how the machine works or anything, and there are a lot of other problems with steel that have been mentioned already, but this could be a workaround.
Does it use Wonderflonium as a power source?
It blew my mind when I finally realized that there was more to it; you could improve your situation and all and actually play it like a game. The fact that it worked on both of those levels probably made it the game I had played the longest/most out of any to date. Although I do still break out the Kirby once in a while just to make sure I can still destroy King Dedede.
The trouble with epoxy potting is getting the heat out of the board. You need to leave the thermally conductive parts outside of the potting so that you can remove the heat. The epoxy itself isn't thermally conductive enough to get processor heat out, even on a processor with passive cooling.
Coming from a materials engineering background, this was my first thought about the question. A material which is very thermally conducting while also electrically insulating sounds like a pretty tall order to me. The reason is that one of the primary methods of heat transfer is through transferring excited electrons.
The two others are phonon transmission through the lattice and radiation. A lot of things which block electrons also block phonon movement (basically heat transfer through vibration) and I'm guessing radiant heat is not going to be sufficient. The one material I do know of which has high thermal conductivity and low electrical conductivity is diamond. It's kind of an oddball, though. I'd be interested to know if there are other, more common materials that would suit this application.
Then there's also the CTE mismatch issue mentioned later in the thread. Whether you design the specs for the high-heat state while it's in use or the cool state when it's off, the other state is going to put a lot of thermal strain on your circuit board components. I'd imagine you could solve some of these problems, but I doubt you're going to be able to take care of them all.
I seriously doubt that humans were holding on to each other for lifetimes before the dawn of religions. After all, the whole idea of staying together forever and ever is all taken from a few books that people wrote hundreds of years ago.
Let's say that we go 10,000 years back.
Did you not see 10,000 B.C.? Eh, can't really blame you.
I guess technically that was 12,000 years back, but it seemed to go on at least long enough to fit into your timeframe.
And before someone goes around throwing the hindenburg in everyone's faces, keep in mind that it was painted with rocket fuel, and that more than half the people on board survived the crash. The same cannot be said for your average airplane.
Paint airplanes with rocket fuel... Brilliant!
I believe it is because the common sense argument does apply when it is convenient for the record companies.
Any plans for what to do as they convert to wind power? Or will power plants be kept as a source of heat with electricity as a brpãduct?
I think they use the steam to power those giant fans you see everywhere. This is where wind comes from, and it's eventually reclaimed by wind turbines. Unfortunately, the wind is being overfarmed, and we need to build more nice big coal power plants to ensure it remains a sustainable source of power.
Every time I hear about the RIAA, they're suing someone new or getting another judgment handed down. Every time I hear about the MPAA, they're trying something new - online services like streaming shows and the whole Netflix thing, "educational" (threatening) letters, or a summer which, in my opinion, has been filled with an unreasonably high number of decent films.
I'm not saying they've gotten things perfect, but it at least looks like they're trying, and it would be nice if people recognize that and throw a noticeable amount of support their way in response. That way, they can see that the evil haX0rs aren't out to get them and the public really is willing to work with them. Because the alternative is that they recognize the RIAA's "bite the hand that feeds you" campaign is turning more of a profit through settlements and go that route. Maybe I've missed news stories where the MPAA does the same thing, but for the sake of not moving to Canada I'd like to think not. It's cold up there. And filled with Canadians.
The flipside of that, of course, is to let the RIAA know how we feel about their strategy. For example, I recently got fed up with them and opened an e-music account. I know there are other sites but I'm a little hooked on this one, you know how it is. It seems to have everything we want straight from a wish list (reasonably priced quality songs without DRM and no RIAA). Like I've seen a lot with similar posts, I missed some of the bigger name bands and it's a little harder to find what I want, but I've also heard that if that sort of thing deters you they take your geek license on the spot.
So yeah, I guess my point here is look around, and use the language they under$tand to tell the *AAs what you like (or don't). That's the only way things will really get better. If you only hide behind "extra features" of illegal services to justify breaking the law, well, sorry to say but they probably are justified in suing that attitude out of you. But if you are willing to support those features, they might actually get implemented. Because, in the immortal words of Peter Griffin, "Black or white, the only color that really matters is green." And I'll continue to watch Family Guy as long as they don't sue me for the $0.02 of whatever I just stole there.
From the article:
Innocent infringement : defendant was not aware of any copyright infringement, and upon information and belief some or all of the copies which she downloaded did not bear copyright notice.
This looks very weird - when people rip CDs and DVDs, they rarely (if ever) attach any copyright notice to the resulting mp3 and avi files... Would it mean, that because the copyright notice has been removed (it was on the CD case for sure, or the load screen of the DVD), then you don't know you are infringing? As much as I applaud the rest of the complaints, this is just silly. On the internet it is mostly: "everything is copyrighted except if it's explicitly noted", not the other way around...
On the other hand, if it gets accepted, then everyone is pretty innocent from this point on... Would be fun. :)
True, but since everyone involved in this matter seems to so enjoy analogies...
Say someone anonymously donates a DVD (or a CD) to a library. It gets rented out to anyone who cares to watch/listen to it gets to, free of charge. Now one day one of the *AAs comes in and says the disc was illegally produced. They have no way of knowing or finding out who produced the copy, so instead they're going to obtain the library's records to sue everyone who touched the thing as well as the library itself.
Maybe the original crook even stripped copy protection somehow and the *AA's now suing for more on the basis that the renters "could" have made the content available online. If not that, they certainly could have shared it with their friends. And they almost definitely viewed it without the license to do so. However, just like the typical targets of online file-sharing stings and lawsuits, they most likely had no idea that what they were doing was wrong.
People don't question free goods/bargains. Don't believe it? How many people wonder even for a second how they can get a decent shirt for a buck or a pair of five/ten dollar shoes? That kind of ignorance leads companies to act illegally/immorally for a competitive advantage anywhere they can get away with it. This scenario could most likely even play out with unreleased material and no one would care until the legal shit went down.
Are these people guilty under some interpretation of the law? I would almost guarantee that the lawyers will spin it that way. Did they really do anything wrong? I'm inclined to say hell no. And some exorbitant six-figure fine or several thousand dollar settlement seems unreasonable to me.
Of course ignorance shouldn't be excused, but if dirty water starts coming in, it doesn't make sense to beat the people bringing it to you. If you want the problem fixed you go after the person who's mucking things up upstream, no matter how hard that may be. Otherwise you deal with it.
Again, I apologize for the analogies, it seems to be the native language of these forums.
Maybe the most important point, at what cost? how rare/expensive is that new material? If is very, maybe the main use would be not for our normal lifes, but maybe for i.e. space probes.
They already use materials like this in space probes - you put a hot radioactive isotope at the end of one of those long rods and thermoelectric generators through the rod - they're ridiculously inefficient right now, but there are no moving parts they're less likely to break down, which is more important on long, unmanned space missions. I'm a materials engineering major and one of the things we were told in our intro class was that if anyone ever figures out a way to make this type of material more efficient, they will make bank.
Theoretically, you can pump them up to a higher efficiency than modern generators and keep the moving parts out, eliminating nearly all of the maintenance costs in power production. So I find this very exciting, although a little disappointing that there's one less target to go after now.
I would definitely agree that teaching him how to cheat at schoolwork would be the most likely way to get and keep him interested.