TRIZ is a step-by-step method for generating innovative solutions. That sounds stupid, I know, but bear with me. TRIZ is based on resolving contradictions between parameters... in classical TRIZ, there are 39 such parameters, mostly engineering focused. You have a contradiction when you have 2 parameters in conflict, where improving one of them makes the other worse. Your ideal solution would have BOTH improve.
Considering air flowing over an airfoil, I can see contradictions between lift (pressure, parameter 11) with speed (parameter 9) and energy spent (parameter 19). TRIZ then suggests inventive principles that might present a solution. Some promising hits appear to be:
Spheroidality - Replace flat parts with curved ones. (principle 14)
Vibration - Set an object into oscillation, or if oscillation exists, increase its frequency. (principle 18)
There are plenty of other ways to look at this, and possibly other principles might come into play. Combinations of principles might work as well... this seems to be the case with the principles found above.
For more info, check out the following site - TRIZ.
Please note that I have no connection with this site.
Wrong wrong wrong! Math and science are critical to a fundamental education. Yes, reading and writing are very important... but since you mentioned it, what about critical thinking? In which classes did you learn logic and analysis? Which classes forced you to think through a problem from beginning to end, and how to learn new things on your own? Match and science classes are not about stuffing your head full of facts and methods... they are about teaching you how to THINK.
When you want to compare two strings you have to make them the same length with a "substr" type operation (eg "STRING1(1:37).EQ. STRING2(1:37)") - it's easy to use, just too crude to be usable.)
Incorrect. Fortran will automatically pad the shorter string with spaces to perform the comparison.
By the way, do you see how easy it is to perform substring operations in Fortran? Since Fortran treats strings like arrays of characters, substring operations become trivially easy to perform. Combine this array-like syntax with the standard selection of intrinsic character functions, and I can do anything I want with a string in Fortran without ever using a single pointer.
Gaseous nuclear fuel has been researched quite a bit, theory-wise, but I don't believe anybody's tried building anything. Most envisioned applications are for space-propulsion, although an interesting use that has been researched quite a bit is for nuclear-pumped laser platforms. The weirdest idea I've seen is in an OLD text-book that I have... a piston engine using gaseous nuclear fuel.
For more info, try looking up something on "Nuclear Lightbulb" engines... a rocket propulsion system in which fissioning uranium plasma inside an arrangement of quartz tubes heats a propellant flowing outside the tubes. The latest concepts (I believe out of the University of Florida) use a fissioning uranium tetrafluoride plasma at 30,000 to 60,000 degrees Kelvin. The ball of plasma is supposedly confined hydronamically by the flow of propellant around it. Don't ask me how. Interesting idea, supposed to be able to obtain a very high specific impulse for propulsion, but I have no idea if it would actually work. You might try searching for "Vapor Core Reactor" or something like that.
Whoops, my bad memory strikes again. Slowpoke is not a water-boiler. Here's some info on Slowpoke.
Re:Killing two birds with one stone
on
Fission in a Box
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· Score: 1
Wasn't slowpoke (and most early research reactors) water boilers with an aqueous solution of uranyl-sulfate or something? No fuel rods, I think... just a big liquid solution with fuel mixed in.
Re:Gas Turbine Modular Helium Reactors
on
Fission in a Box
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· Score: 1
Sorry... that was long. Short answer... the probability of fission in fuel material is extremely dependent on both fuel and moderator temperatures. Guaranteeing negative temperature coefficient of reactivity over all core conditions is a good thing, although a positive coefficient can be mitigated through good design.
Re:Gas Turbine Modular Helium Reactors
on
Fission in a Box
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· Score: 1
You've got several different types of "temperature" coefficients. First, there's thermal expansion of the fuel material, moving fuel atoms further apart. Then there's energy-spectrum shift... nuclear fission cross-sections of various fuel materials vary greatly with energy spectrum, which is affected by temperature. Then there's similar effects due to moderator materials, either direct through temperature or through voiding (boiling) of moderator or coolant. The scattering properties of light water, for instance, are affected by the temperature and density of water... or in the case of boiling, the overall density of the water could be so low that neutron moderating efficiency (scattering neutrons down to thermal energies, where they're most efficiently absorbed by fuel nuclei) is decreased greatly.
MTC (moderator temperature coefficient) in modern LWRs (light-water reactors) is usually negative at beginning of core life (a core is usually designed to last 18 to 24 months). This is because LWRs are designed to be under-moderated, i.e. less than optimum moderation, so that increases in temperature (and decrease in density) of the moderator cause the fission reaction to slow down. However, it is possible to have positive MTC near middle to end of core life due to conversion of U-238 to Pu-239 in the core (2/3 of power generated from a fuel element is by plutonium at end of fuel element life), and the core, on average, may be slightly over-moderated because of this.
Another situation is where you have a graphite moderator and light water coolant, as in the RBMK reactor (Chernobyl type). In this case, there are situations wherein heat-up of the coolant (making it less dense) increases the moderating effectiveness of the graphite... i.e., flashing coolant leading to bad things happening. This would actually be termed a positive void-coefficient of reactivity, as opposed to a temperature coefficient... but whatever.
The situation described above for Chernobyl is not an issue for a gas-cooled reactor using helium coolant, like the HTGR or the PBMR. Helium gas has no nuclear cross-section to speak of, so does not affect the moderation of neutrons at any temperature, high or low. That's a desirable feature.
Re:Gas Turbine Modular Helium Reactors
on
Fission in a Box
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· Score: 1
When Fort St. Vrain was built, I don't think it was called a GTHMR... just HTGR for High Temperature Gas-cooled Reactor. Same thing for Peach Bottom 1. Neither of these plants used a direct-cycle gas turbine for energy conversion; there was a steam generator with core-coolant helium on one side, and water/steam on the other to drive a normal steam turbine. They had terrible seal-leakage problems at St. Vrain with their main helium circulators; monatomic helium is incredibly tiny, and very difficult to keep from leaking everywhere. The core internals design for these older HTGRs and the PBMR featured in the article is very different also. The HTGR fuel used similar fuel-spheres, but they were packed into large, hexagonal graphite blocks with integral coolant channels. The blocks interlocked to form the core. Nice idea, but I imagine refueling was a bitch. The fuel cycle for these plants was supposed to be that of a thermal breeder, with a uranium-thorium fuel cycle. The breeding ratio was not terribly high, but I believe it was shown to be greater than unity (i.e., more fissile uranium created than consumed). I don't know too much about the history of Peach Bottom 1, but there is a lot of good information about Fort St. Vrain at the following location: Fort St. Vrain History.
You are talking about a pebble-bed reactor, and there is someone working on commercializing this technology, now dubbed the "Pebble Bed Modular Reactor" or PBMR. See this link for some info:
Make twice as much, pay much less in taxes, and have more earnings potential down the road, I suspect. At least, that's what I hear from my Canadian friends as reasons to come to the US. The so-called "brain drain" must be pretty bad if even I've heard of it down here in mucky Louisiana...
The company I work for is quite fond of the MBTI, especially when forming large cross-discipline teams. I'm not sure the results were used particularly effectively in my case... or maybe they were, I don't know. I always get stuck with people that are absolutely certain to drive me mad. Maybe they formed the group that way because I would keep my mouth shut about it (being an INTP), or because of other reasons. Perhaps I'm expendable, and it doesn't matter if I go mad.
It is interesting to see how well MBTI clusters people into various areas of the map, however. For example, 90% of all managers and supervisors were within one or two boxes, system engineers were in another area, etc. And yes, all the people that were absolutely guaranteed to drive me mad were grouped together.
One other note... I had a Chemistry professor in college that gave a very abbreviated form of type test. He used the results to decide who sat up front in the >300 seat lecture hall. His rationale was that some types would do well no matter where they sat, but others almost always did better when sitting up front. I don't know... it seems to me the front of the hall was pretty much loaded with females. Hehe, come to think of it, that's not a bad result (for the professor, since he was a guy)...
You're sadly misinformed if you think oil-fired power plants are more economical than nuclear. Oil tends to be the most expensive fuel, and coal the least expensive. Nuclear, especially now that plants are running so well, are essentially competitive with coal in terms of operation and maintenance costs. So nuclear plants are not MORE EXPENSIVE TO RUN as you claim, but are a helluva lot cheaper than oil and basically the same as coal.
"Let's not even get into Nuclear Technologies, which countries are abandoning en masse as they are far too expensive in the short term, let alone the incalculable costs in the longer term."
Far too expensive? Then why not shut down all the plants right now? Well, maybe not, because most plants can still make money producing power, both safely and efficiently.
And what about those incalculable costs? How do they compare to continued reliance on fossil fuels? Do you even know the volume of high level waste generated by a typical 1000 MWe plant in one year? How does the volume of waste from a typical nuclear power plant compare to the waste generated by other forms of energy production? And what about the benefits? Does freedom from greenhouse gas emission mean anything?
If you'd like to learn a little more about what you're dismissing as "too expensive" and "too costly", here's a good site to visit.
That you might not have all the details on this? I've seen a lot of posts castigating Boeing for this. Did you stop to think it might be NASA's fault? Or maybe the Redstone Arsenal trash contractor's? This happened at Marshall Space Flight Center, didn't it? So what if it was a part Boeing made. Who put the part outside the building in the first place? We have very few facts, and there are numerous possible explanations for how this could have happened. And no, I do not work for Boeing. I don't even work in Huntsville.
Please pardon my ignorance here. I just listened to the sample audio track for this thing. I'm interested by the performance of the neural network on the set of four words "yes, no, fire, stop" with varying levels of conversation noise added. Listening to the samples, it occurred to me that even though there was no way in hell I could actually understand which words were being spoken, I noticed that you can almost tell which word is spoken simply by the length of each sample. So... is the neural network actually recognizing the words spoken, or just keying off the sample lengths?
According to this very informative article on NucNet, the maximum dose equivalent received by a single individual was approximately 8 Sieverts (800 REM). This is a HUGE dose equivalent. The normal US limit for radiation workers is 5 REM per year, I believe.
I mentioned Grays and RADs above, which are simply dose, as opposed to dose equivalent, which factors in absorbed dose and biological effects. As a first cut, you could assume a one-to-one correspondence between dose and dose equivalent. So, to put 800 REM in perspective, you basically have a dose around 800 RAD. Since the LD-50/30 dose is about 700 RAD... well, this person has less than a 50/50 chance of surviving over the next 30 days.
In the US, there is no operating commercial reactor from a standard design. However, there are a lot of similarities in how US plants of different design are operated, maintained, etc.
Other countries did a little better job at standardizing, France in particular. Korea is also doing very well at standardizing their plant designs. And even the US is not doing too badly in the standard design area. True, none of these "standard" designs have been built in the US yet, but there are some in other countries. Japan has the GE Advanced Boiling Water Reactors at Kashiwazaki Kariwa (Units 6 and 7). Korea has several ABB System 80 pressurized water reactor plants. Both of these are the bases for the next generation of standard US plant designs.
This is sort of correct, but the conclusion you draw is not entirely accurate. Yes, alphas and betas are stopped fairly easily. Alphas can generally be stopped by a single sheet of paper... or your outer layer of dead skin. Betas are a little more penetrating, they make it past your skin before stopping. Neutrons and gammas are more penetrating yet, they go a good ways inside before they stop.
The problem is this. While alphas may be slowed down and stopped easily, they give up a lot of kinetic energy as they do so. They are rather massive (basically a helium nucleus), and strongly charged (+2). This is why they stop so quickly, shedding all their kinetic energy in a relatively small space as they slow down. That's why it's not good to inhale alpha emitters... there's a lot of soft tissue in your lungs, and alpha emitters can screw it up royally. But basically, you have to ingest alpha emitters for there to be any damage.
Betas are different. They're less massive (basically an electron), but are still charged (-1 or +1). Betas are weakly penetrating, but impart a fair amount of energy as they slow down. Generally speaking, the most common hazard from betas is dose to the lens of the eye.
Neutrons, being uncharged, don't slow down as rapidly as alphas or betas. They do slow down though... either by scattering off light nuclei (hydrogen and carbon... hmm, not much of that in the human body, is there?) or by being absorbed. In the process of slowing down, neutrons have the capability of inducing ionization in the materials through which they're traveling. Or, they can be absorbed, causing nuclear transormations which can lead to emission of other types of ionizing radiations. But as far as risk from neutrons go, it's the induced ionization that is more of a problem.
Finally, there's gamma radiation (high energy photons). These are very penetrating, probably passing all the way through your body, but probably causing some damage along the way. The damage from gammas is not usually direct, however. A gamma may, when passing close by a nucleus, spontaneously disappear and be replaced by an electron and a positron. If a gamma undergoes scattering off an electron, the electron could be released. In both these cases, you've had a release of charged particles that will interact with the material around them.
So what I'm getting at, basically, is that all radiation presents a risk. The amount of risk is dependent on the type of radiation, the amount of radiation, the energy of that radiation, where the radiation is, the properties of the material the radiation's traveling through, etc. etc. etc. It's pretty hard to say that any one type is worse for you than another... it all depends.
Slashdot Mirror
Okay... imagine a Beowulf cluster of these! Actually, here it is.
TRIZ is a step-by-step method for generating innovative solutions. That sounds stupid, I know, but bear with me. TRIZ is based on resolving contradictions between parameters... in classical TRIZ, there are 39 such parameters, mostly engineering focused. You have a contradiction when you have 2 parameters in conflict, where improving one of them makes the other worse. Your ideal solution would have BOTH improve.
Considering air flowing over an airfoil, I can see contradictions between lift (pressure, parameter 11) with speed (parameter 9) and energy spent (parameter 19). TRIZ then suggests inventive principles that might present a solution. Some promising hits appear to be:
There are plenty of other ways to look at this, and possibly other principles might come into play. Combinations of principles might work as well... this seems to be the case with the principles found above.
For more info, check out the following site - TRIZ.
Please note that I have no connection with this site.
Wrong wrong wrong! Math and science are critical to a fundamental education. Yes, reading and writing are very important... but since you mentioned it, what about critical thinking? In which classes did you learn logic and analysis? Which classes forced you to think through a problem from beginning to end, and how to learn new things on your own? Match and science classes are not about stuffing your head full of facts and methods... they are about teaching you how to THINK.
Too late, Emacs has already passed becoming an OS. It is now on its way towards becoming sentient.
When you want to compare two strings you have to make them the same length with a "substr" type operation (eg "STRING1(1:37) .EQ. STRING2(1:37)") - it's easy to use, just too crude to be usable.)
Incorrect. Fortran will automatically pad the shorter string with spaces to perform the comparison.
By the way, do you see how easy it is to perform substring operations in Fortran? Since Fortran treats strings like arrays of characters, substring operations become trivially easy to perform. Combine this array-like syntax with the standard selection of intrinsic character functions, and I can do anything I want with a string in Fortran without ever using a single pointer.
> (sigh) I've had that last one, and it ain't fun. Imodium usually clears it up quick though...
In your case, was it streaming or steaming?
For more info, try looking up something on "Nuclear Lightbulb" engines... a rocket propulsion system in which fissioning uranium plasma inside an arrangement of quartz tubes heats a propellant flowing outside the tubes. The latest concepts (I believe out of the University of Florida) use a fissioning uranium tetrafluoride plasma at 30,000 to 60,000 degrees Kelvin. The ball of plasma is supposedly confined hydronamically by the flow of propellant around it. Don't ask me how. Interesting idea, supposed to be able to obtain a very high specific impulse for propulsion, but I have no idea if it would actually work. You might try searching for "Vapor Core Reactor" or something like that.
Whoops, my bad memory strikes again. Slowpoke is not a water-boiler. Here's some info on Slowpoke.
Wasn't slowpoke (and most early research reactors) water boilers with an aqueous solution of uranyl-sulfate or something? No fuel rods, I think... just a big liquid solution with fuel mixed in.
Sorry... that was long. Short answer... the probability of fission in fuel material is extremely dependent on both fuel and moderator temperatures. Guaranteeing negative temperature coefficient of reactivity over all core conditions is a good thing, although a positive coefficient can be mitigated through good design.
MTC (moderator temperature coefficient) in modern LWRs (light-water reactors) is usually negative at beginning of core life (a core is usually designed to last 18 to 24 months). This is because LWRs are designed to be under-moderated, i.e. less than optimum moderation, so that increases in temperature (and decrease in density) of the moderator cause the fission reaction to slow down. However, it is possible to have positive MTC near middle to end of core life due to conversion of U-238 to Pu-239 in the core (2/3 of power generated from a fuel element is by plutonium at end of fuel element life), and the core, on average, may be slightly over-moderated because of this.
Another situation is where you have a graphite moderator and light water coolant, as in the RBMK reactor (Chernobyl type). In this case, there are situations wherein heat-up of the coolant (making it less dense) increases the moderating effectiveness of the graphite... i.e., flashing coolant leading to bad things happening. This would actually be termed a positive void-coefficient of reactivity, as opposed to a temperature coefficient... but whatever.
The situation described above for Chernobyl is not an issue for a gas-cooled reactor using helium coolant, like the HTGR or the PBMR. Helium gas has no nuclear cross-section to speak of, so does not affect the moderation of neutrons at any temperature, high or low. That's a desirable feature.
When Fort St. Vrain was built, I don't think it was called a GTHMR... just HTGR for High Temperature Gas-cooled Reactor. Same thing for Peach Bottom 1. Neither of these plants used a direct-cycle gas turbine for energy conversion; there was a steam generator with core-coolant helium on one side, and water/steam on the other to drive a normal steam turbine. They had terrible seal-leakage problems at St. Vrain with their main helium circulators; monatomic helium is incredibly tiny, and very difficult to keep from leaking everywhere. The core internals design for these older HTGRs and the PBMR featured in the article is very different also. The HTGR fuel used similar fuel-spheres, but they were packed into large, hexagonal graphite blocks with integral coolant channels. The blocks interlocked to form the core. Nice idea, but I imagine refueling was a bitch. The fuel cycle for these plants was supposed to be that of a thermal breeder, with a uranium-thorium fuel cycle. The breeding ratio was not terribly high, but I believe it was shown to be greater than unity (i.e., more fissile uranium created than consumed). I don't know too much about the history of Peach Bottom 1, but there is a lot of good information about Fort St. Vrain at the following location: Fort St. Vrain History.
It is interesting to see how well MBTI clusters people into various areas of the map, however. For example, 90% of all managers and supervisors were within one or two boxes, system engineers were in another area, etc. And yes, all the people that were absolutely guaranteed to drive me mad were grouped together.
One other note... I had a Chemistry professor in college that gave a very abbreviated form of type test. He used the results to decide who sat up front in the >300 seat lecture hall. His rationale was that some types would do well no matter where they sat, but others almost always did better when sitting up front. I don't know... it seems to me the front of the hall was pretty much loaded with females. Hehe, come to think of it, that's not a bad result (for the professor, since he was a guy)...
Remember when SLS was king? Ahhh, the good old days.
Take a look at your list. Every single thing you mention depends in some way on something on THEIR list.
You're sadly misinformed if you think oil-fired power plants are more economical than nuclear. Oil tends to be the most expensive fuel, and coal the least expensive. Nuclear, especially now that plants are running so well, are essentially competitive with coal in terms of operation and maintenance costs. So nuclear plants are not MORE EXPENSIVE TO RUN as you claim, but are a helluva lot cheaper than oil and basically the same as coal.
Far too expensive? Then why not shut down all the plants right now? Well, maybe not, because most plants can still make money producing power, both safely and efficiently.
And what about those incalculable costs? How do they compare to continued reliance on fossil fuels? Do you even know the volume of high level waste generated by a typical 1000 MWe plant in one year? How does the volume of waste from a typical nuclear power plant compare to the waste generated by other forms of energy production? And what about the benefits? Does freedom from greenhouse gas emission mean anything?
If you'd like to learn a little more about what you're dismissing as "too expensive" and "too costly", here's a good site to visit.
Virtual Nuclear Tourist
That you might not have all the details on this? I've seen a lot of posts castigating Boeing for this. Did you stop to think it might be NASA's fault? Or maybe the Redstone Arsenal trash contractor's? This happened at Marshall Space Flight Center, didn't it? So what if it was a part Boeing made. Who put the part outside the building in the first place? We have very few facts, and there are numerous possible explanations for how this could have happened. And no, I do not work for Boeing. I don't even work in Huntsville.
Please pardon my ignorance here. I just listened to the sample audio track for this thing. I'm interested by the performance of the neural network on the set of four words "yes, no, fire, stop" with varying levels of conversation noise added. Listening to the samples, it occurred to me that even though there was no way in hell I could actually understand which words were being spoken, I noticed that you can almost tell which word is spoken simply by the length of each sample. So... is the neural network actually recognizing the words spoken, or just keying off the sample lengths?
According to this very informative article on NucNet, the maximum dose equivalent received by a single individual was approximately 8 Sieverts (800 REM). This is a HUGE dose equivalent. The normal US limit for radiation workers is 5 REM per year, I believe.
I mentioned Grays and RADs above, which are simply dose, as opposed to dose equivalent, which factors in absorbed dose and biological effects. As a first cut, you could assume a one-to-one correspondence between dose and dose equivalent. So, to put 800 REM in perspective, you basically have a dose around 800 RAD. Since the LD-50/30 dose is about 700 RAD... well, this person has less than a 50/50 chance of surviving over the next 30 days.
I sincerely hope this person makes it.
In the US, there is no operating commercial reactor from a standard design. However, there are a lot of similarities in how US plants of different design are operated, maintained, etc.
Other countries did a little better job at standardizing, France in particular. Korea is also doing very well at standardizing their plant designs. And even the US is not doing too badly in the standard design area. True, none of these "standard" designs have been built in the US yet, but there are some in other countries. Japan has the GE Advanced Boiling Water Reactors at Kashiwazaki Kariwa (Units 6 and 7). Korea has several ABB System 80 pressurized water reactor plants. Both of these are the bases for the next generation of standard US plant designs.
You would get a significant dose of photons as well.
This is sort of correct, but the conclusion you draw is not entirely accurate. Yes, alphas and betas are stopped fairly easily. Alphas can generally be stopped by a single sheet of paper... or your outer layer of dead skin. Betas are a little more penetrating, they make it past your skin before stopping. Neutrons and gammas are more penetrating yet, they go a good ways inside before they stop.
The problem is this. While alphas may be slowed down and stopped easily, they give up a lot of kinetic energy as they do so. They are rather massive (basically a helium nucleus), and strongly charged (+2). This is why they stop so quickly, shedding all their kinetic energy in a relatively small space as they slow down. That's why it's not good to inhale alpha emitters... there's a lot of soft tissue in your lungs, and alpha emitters can screw it up royally. But basically, you have to ingest alpha emitters for there to be any damage.
Betas are different. They're less massive (basically an electron), but are still charged (-1 or +1). Betas are weakly penetrating, but impart a fair amount of energy as they slow down. Generally speaking, the most common hazard from betas is dose to the lens of the eye.
Neutrons, being uncharged, don't slow down as rapidly as alphas or betas. They do slow down though... either by scattering off light nuclei (hydrogen and carbon... hmm, not much of that in the human body, is there?) or by being absorbed. In the process of slowing down, neutrons have the capability of inducing ionization in the materials through which they're traveling. Or, they can be absorbed, causing nuclear transormations which can lead to emission of other types of ionizing radiations. But as far as risk from neutrons go, it's the induced ionization that is more of a problem.
Finally, there's gamma radiation (high energy photons). These are very penetrating, probably passing all the way through your body, but probably causing some damage along the way. The damage from gammas is not usually direct, however. A gamma may, when passing close by a nucleus, spontaneously disappear and be replaced by an electron and a positron. If a gamma undergoes scattering off an electron, the electron could be released. In both these cases, you've had a release of charged particles that will interact with the material around them.
So what I'm getting at, basically, is that all radiation presents a risk. The amount of risk is dependent on the type of radiation, the amount of radiation, the energy of that radiation, where the radiation is, the properties of the material the radiation's traveling through, etc. etc. etc. It's pretty hard to say that any one type is worse for you than another... it all depends.