Actually, I believe that the efficiency rating measures how much of the heat produced is captured for use in heating the building vs. how much goes up the chimney. Those 97% efficent furnaces have very efficient heat exchangers so that only 3% of the heat produced goes up the chimney. If 3% of the natural gas was going unburned, that would be a huge pollution problem.
I was pointing out that the Carnot Cycle does not affect all processes, only the proceses which attempt to convert heat into work.
See my previous post. The Carnot cycle limits the efficiency of the conversion of heat into work, but there are processes which are not Carnot limited. Fuel cells, for example. You can buy 97% efficient gas furnaces.
Actually the Carnot cycle puts a limit on the conversion of heat energy into any other form of energy (kinetic, potential, electrical, magnetic, chemical, nuclear, etc). However, heat is the only form of energy so limited. Other conversions, say chemical => electrical are only limited by the second law of thermodynamics. For that matter, converting any other energy to heat can be very efficient. Electrical energy => heat, for example.
So, something like a microturbine is limited to ~30% efficiency for electricity generation. Larger plants can get up to 35% efficiency. A fuel cell has no such limit and could potentially reach into the 90% range for efficiency of electricity generation. Hybrid fuel cell-turbine generation systems are being tested which have efficiencies of over 50% and they speculate that they could hit 70% or more. The problem with such a system is that the upfront cost is very high and it does not get offset by the savings in fuel. Not yet, anyway.
Remember too that conversion of any energy to heat can be very efficient. Natural gas furnaces can be extremely efficient, as high as 97%. That's because converting chemical energy => heat is not a Carnot limited process, and is only limited by the second law of thermodynamics.
Sorry, I realized after I submitted the comment that I didn't phrase that right. I appreciate open source, but I don't think it should be manditory or anything.
Anyway, my comment could have been modded (-1:Redundant), just on account of the fact that I posted one of the obvious advantages of open source on Slashdot.:-)
You're working yourself up here... Consider this like Red Hat refusing to patch up Red Hat 3.0 with the latest security fixes.
Except that the source code to Red Hat 3.0 is publicly available, so a fix could be made by anybody. The problem here is that the only people who could fix NT4 is Microsoft and they are refusing to do so. Worse, we can only take their word for it that a fix would be nearly impossible.
I'm not a big proponent of open source, but this is a case where there are clear advantages.
I guessed it was because the moderators saw it as a joke. It seems a little humourous to me.
If it had been modded up as "funny", I would agree with you. However, the post was getting "insightful" mods. There was nothing insightful about it. I try not to get too up in arms about moderation, but that was just dumb. I seem to have had the desired effect, as the post was modded back down. I don't care if it gets modded back up as "funny", but to allow that post to get (Score:5, Insightful) is insulting to most of the/. community. It's like the karma whores who post CNN articles in the comments "in case of slashdotting", as though CNN doesn't handle vastly more traffic than Slashdot does.
Slashdot is a high traffic website, and as such, it has to be designed to handle the load that it gets. Sites that get/.ed are usually low traffic sites that aren't set up to the sort of page views that Slashdot.
OTOH, Slashdot generally doesn't have any effect on other high traffic sites. You don't see the/. effect on sites like CNN, Microsoft, Apple, Cisco, or the NY Times. It is when Slashdot links to someone who put up a picture of their case mod, they likely aren't set up to handle the same sort of traffic that/. does and they become inaccessable.
Sometimes you can get the airlines to let you change those "non-refundable" fares if you give them enough evidence that your reason for changing was beyond your control.
I've heard the thing to do is to go to the airport, so you can talk to an actual human being face to face. Explain that you booked a flight to go to this conference, the conference got pushed back a month, and you'd like to reschedule your flight so that you can attend the rescheduled conference. Have printed documentation of what happened. If you can convince them that this was something you couldn't forsee, they willl often give you a break. Don't try this over a phone call, though. It won't work.
I did some research and found that the inclusion of a clock was the culprit
No, you and everyone else blamed the clock, as it was the only apparant change to the iPod firmware that seemed like it might have introduced a drain on the battery.
However, if this update works, it blows that theory out of the water. The knowledgebase article for this says that the problem was that the iPod was incorrectly interpreting the battery charge. It seems that the 1.2 firmware was not allowing the iPod to use all of the battery capacity, and was shutting down when there was still plenty of life left. There is no way anyone outside of Apple could have figured this out, so the clock got blamed.
is it possible to run Darwin/PowerPC binaries on Linux/PowerPC?
I believe that Darwin and LinuxPPC are mostly binary compatible. Even Xwindows apps will run on both. I don't think the differences are any worse than Linux and FreeBSD
The idea of the code morphing is that any ISA could emulated. x86 is the only emulation that they focus on, but it should be able to emulate PPC, Alpha, MIPS, Z-80, you name it.
Yeah, I kind of wonder why there aren't more Java apps myself. I took it upon myself to write a program for statistical design of experiments about a year ago. I wasn't happy with any of the software I had used, so I picked up a matrix library that NIST and Mathworks made available for Java.
Now, I didn't know Java when I started. I learned Pascal in college and I've made a few attempts to learn C++, but I've never really succeded.
I picked Java for this project because I intended it for educational purposes and I'm not delusional enough to think that anyone would adopt my program if it was MacOS X only.
Anyway, long story short, I've written a beta quality piece of software for statistical design of experiments using the Java/Swing API. I thought it was pretty easy to work with, and the speed is more than adequate, even on my iBook/500.
I think the reason you don't see more Java Apps is just that not many people have inscentive to write their programs for cross platform use. If I had been a Windows user, I probably wouldn't have cared about the people who don't use windows and just learned C++ and the Win32 api. There wouldn't be the inscentive to capture the other 5-10% that doesn't run Windows. Even most Mac or Linux programmers don't care. Even though Java really is "fast enough" for most things.
BTW: if anybody would like to beta test some Java software for Statistical DOE, email me. Let's see... Take my slashdot username and email me with that at mac.com.
The problem was that if you have a voice over with no motion going on, people get restless and don't pay attention. (This being the MTV based concentration deprived generations)
That is a little harsh. One of the reasons the effect is so appealing is that human vision is tuned to picking up motion. The other thing is that a TV is not designed to display still pictures, so a moving still picture will look better on a TV than a stationary one.
And yes, it is the same Ken Burns of "The Civil War" et al. "The Ken Burns Effect" was the developmental name for Apple's pan & zoom effect, but when they showed it to Ken Burns himself, he gave his blessing to use his name in the finished product.
hy would SCSI be less prone to heat and wear than IDE?
I think the point was just that SCSI provides better performance, even with 7200RPM. Much of that comes from the fact that SCSI drives are "smart" and require almost no CPU time, whereas IDE drives are "dumb", and require the CPU to handle much of the work.
A fuel cell IS a battery. It is a refillable battery. One of the biggest anoyances of rechargable batteries is how long they take to recharge. That is the reason (well, one of them) that electric cars have never become popular. If you run out of juice, they take HOURS to recharge.
With laptops, this problem is not so bad. You can use a laptop while it is recharging, and most places you would want to use a laptop, you will be within range of a plug anyway. Still, there are times when I would like to be able to run unteathered for long periods of time. So whenever the fuel cell gets low, you just add some more methanol and in seconds, you're good to go for another 5 hours.
Well, OpenBSD only counts remote root exploits. Since sendmail isn't activated externally by default, then it can't be exploited.
Plenty of software that ships with OpenBSD have exploits from time to time. It is just that there has only been one known remote root exploit turned on in the default install of OpenBSD in the past seven years.
I don't think the bus speed changes with processor speed for the 970, only the multiplier. It is still a 900MHz effective bus (225-quad pumped, IIRC). Much better than the 166 SDR bus on the current G4's.
Fortunately, Apple's Policy will give you a price adjustment on your existing system. They should drop it down to at least the price of a new system, and probably a little below.
That way you get to keep the existing server without feeling ripped off and use it during the 6 weeks you'd be waiting for a new one anyway.
FWIW: BS in Materials Science, '98, CWRU, and I'm finishing up my Ph.D in Materials Science at Northwestern University right now.
Admittedly my specialty is ceramics, but I have friends in polymers and I know more about materials than the average geek. I use polymers as part of the processing technique that I use, and I've spent the past week investigating the properties of various polymer films. Don't get me started....
I'm not sure what your point is. Sodium and aluminum have vastly different properties. Sodium would be useless for a structural applications because it is so reactive. Aluminum is also very reactive, but it quickly forms a thin protective oxide layer that prevents further oxidation. Even so, you would have no hope arguing that they are not both metals
I realize that cars are not brush painted, but it doesn't change my statement. IAAMS (I am a materials scientist). I have friends who work on paint.
Let's get our semantics right. All plastics are polymers. Not all polymers are what we would call "plastics" (e.g. DNA), but from an engineering perspective, virtually all polymers are interrelated.
Your example shows you don't know what your are talking about. Acrylic is a plastic. You can buy chunks of it from McMaster-Carr. It is dissolved in a solvent and sprayed on for paint, but what do you think happens when the solvent dissolves? The acrylic re-deposits to form a film, but it is still fundamentally the same material that is used to make those clear tumblers you can buy at Crate & Barrel.
Can you heat it up and cause the film to flow? Yes, but that just makes it a thermoplastic (as opposed to a thermoset). You could do the same thing with a polyethylene film. The difference with polyethylene is that the flow temperature is about 120C (250F), whereas Acrylic will flow at temperatures closer to 60C (150F).
All paint contains a lot of highly engineered polymers with adhesive properties. Thus, paint amounts to brush on (or spray on) plastic coatings.
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Actually, I believe that the efficiency rating measures how much of the heat produced is captured for use in heating the building vs. how much goes up the chimney. Those 97% efficent furnaces have very efficient heat exchangers so that only 3% of the heat produced goes up the chimney. If 3% of the natural gas was going unburned, that would be a huge pollution problem.
I was pointing out that the Carnot Cycle does not affect all processes, only the proceses which attempt to convert heat into work.
See my previous post. The Carnot cycle limits the efficiency of the conversion of heat into work, but there are processes which are not Carnot limited. Fuel cells, for example. You can buy 97% efficient gas furnaces.
Reread your thermodynamics.
Actually the Carnot cycle puts a limit on the conversion of heat energy into any other form of energy (kinetic, potential, electrical, magnetic, chemical, nuclear, etc). However, heat is the only form of energy so limited. Other conversions, say chemical => electrical are only limited by the second law of thermodynamics. For that matter, converting any other energy to heat can be very efficient. Electrical energy => heat, for example.
So, something like a microturbine is limited to ~30% efficiency for electricity generation. Larger plants can get up to 35% efficiency. A fuel cell has no such limit and could potentially reach into the 90% range for efficiency of electricity generation. Hybrid fuel cell-turbine generation systems are being tested which have efficiencies of over 50% and they speculate that they could hit 70% or more. The problem with such a system is that the upfront cost is very high and it does not get offset by the savings in fuel. Not yet, anyway.
Remember too that conversion of any energy to heat can be very efficient. Natural gas furnaces can be extremely efficient, as high as 97%. That's because converting chemical energy => heat is not a Carnot limited process, and is only limited by the second law of thermodynamics.
Sorry, I realized after I submitted the comment that I didn't phrase that right. I appreciate open source, but I don't think it should be manditory or anything.
Anyway, my comment could have been modded (-1:Redundant), just on account of the fact that I posted one of the obvious advantages of open source on Slashdot. :-)
Except that the source code to Red Hat 3.0 is publicly available, so a fix could be made by anybody. The problem here is that the only people who could fix NT4 is Microsoft and they are refusing to do so. Worse, we can only take their word for it that a fix would be nearly impossible.
I'm not a big proponent of open source, but this is a case where there are clear advantages.
I thought the joke was:
If it had been modded up as "funny", I would agree with you. However, the post was getting "insightful" mods. There was nothing insightful about it. I try not to get too up in arms about moderation, but that was just dumb. I seem to have had the desired effect, as the post was modded back down. I don't care if it gets modded back up as "funny", but to allow that post to get (Score:5, Insightful) is insulting to most of the /. community. It's like the karma whores who post CNN articles in the comments "in case of slashdotting", as though CNN doesn't handle vastly more traffic than Slashdot does.
OK, why did this get modded up?
Slashdot is a high traffic website, and as such, it has to be designed to handle the load that it gets. Sites that get /.ed are usually low traffic sites that aren't set up to the sort of page views that Slashdot.
OTOH, Slashdot generally doesn't have any effect on other high traffic sites. You don't see the /. effect on sites like CNN, Microsoft, Apple, Cisco, or the NY Times. It is when Slashdot links to someone who put up a picture of their case mod, they likely aren't set up to handle the same sort of traffic that /. does and they become inaccessable.
Sometimes you can get the airlines to let you change those "non-refundable" fares if you give them enough evidence that your reason for changing was beyond your control.
I've heard the thing to do is to go to the airport, so you can talk to an actual human being face to face. Explain that you booked a flight to go to this conference, the conference got pushed back a month, and you'd like to reschedule your flight so that you can attend the rescheduled conference. Have printed documentation of what happened. If you can convince them that this was something you couldn't forsee, they willl often give you a break. Don't try this over a phone call, though. It won't work.
No, you and everyone else blamed the clock, as it was the only apparant change to the iPod firmware that seemed like it might have introduced a drain on the battery.
However, if this update works, it blows that theory out of the water. The knowledgebase article for this says that the problem was that the iPod was incorrectly interpreting the battery charge. It seems that the 1.2 firmware was not allowing the iPod to use all of the battery capacity, and was shutting down when there was still plenty of life left. There is no way anyone outside of Apple could have figured this out, so the clock got blamed.
I believe that Darwin and LinuxPPC are mostly binary compatible. Even Xwindows apps will run on both. I don't think the differences are any worse than Linux and FreeBSD
The idea of the code morphing is that any ISA could emulated. x86 is the only emulation that they focus on, but it should be able to emulate PPC, Alpha, MIPS, Z-80, you name it.
Now, I didn't know Java when I started. I learned Pascal in college and I've made a few attempts to learn C++, but I've never really succeded.
I picked Java for this project because I intended it for educational purposes and I'm not delusional enough to think that anyone would adopt my program if it was MacOS X only.
Anyway, long story short, I've written a beta quality piece of software for statistical design of experiments using the Java/Swing API. I thought it was pretty easy to work with, and the speed is more than adequate, even on my iBook/500.
I think the reason you don't see more Java Apps is just that not many people have inscentive to write their programs for cross platform use. If I had been a Windows user, I probably wouldn't have cared about the people who don't use windows and just learned C++ and the Win32 api. There wouldn't be the inscentive to capture the other 5-10% that doesn't run Windows. Even most Mac or Linux programmers don't care. Even though Java really is "fast enough" for most things.
BTW: if anybody would like to beta test some Java software for Statistical DOE, email me. Let's see... Take my slashdot username and email me with that at mac.com.
That is a little harsh. One of the reasons the effect is so appealing is that human vision is tuned to picking up motion. The other thing is that a TV is not designed to display still pictures, so a moving still picture will look better on a TV than a stationary one.
And yes, it is the same Ken Burns of "The Civil War" et al. "The Ken Burns Effect" was the developmental name for Apple's pan & zoom effect, but when they showed it to Ken Burns himself, he gave his blessing to use his name in the finished product.
I think the point was just that SCSI provides better performance, even with 7200RPM. Much of that comes from the fact that SCSI drives are "smart" and require almost no CPU time, whereas IDE drives are "dumb", and require the CPU to handle much of the work.
The price differential, OTOH, is substantial.
A fuel cell IS a battery. It is a refillable battery. One of the biggest anoyances of rechargable batteries is how long they take to recharge. That is the reason (well, one of them) that electric cars have never become popular. If you run out of juice, they take HOURS to recharge.
With laptops, this problem is not so bad. You can use a laptop while it is recharging, and most places you would want to use a laptop, you will be within range of a plug anyway. Still, there are times when I would like to be able to run unteathered for long periods of time. So whenever the fuel cell gets low, you just add some more methanol and in seconds, you're good to go for another 5 hours.
Plenty of software that ships with OpenBSD have exploits from time to time. It is just that there has only been one known remote root exploit turned on in the default install of OpenBSD in the past seven years.
Only if sendmail is turned on by default, and I don't think it is.
I don't think the bus speed changes with processor speed for the 970, only the multiplier. It is still a 900MHz effective bus (225-quad pumped, IIRC). Much better than the 166 SDR bus on the current G4's.
Yep,
Just like OS/2....
I'm not aware of nanotubes being used in anything structural yet. Post below if I'm wrong.
That way you get to keep the existing server without feeling ripped off and use it during the 6 weeks you'd be waiting for a new one anyway.
Why do I bother?
FWIW: BS in Materials Science, '98, CWRU, and I'm finishing up my Ph.D in Materials Science at Northwestern University right now.
Admittedly my specialty is ceramics, but I have friends in polymers and I know more about materials than the average geek. I use polymers as part of the processing technique that I use, and I've spent the past week investigating the properties of various polymer films. Don't get me started....
I'm not sure what your point is. Sodium and aluminum have vastly different properties. Sodium would be useless for a structural applications because it is so reactive. Aluminum is also very reactive, but it quickly forms a thin protective oxide layer that prevents further oxidation. Even so, you would have no hope arguing that they are not both metals
Let's get our semantics right. All plastics are polymers. Not all polymers are what we would call "plastics" (e.g. DNA), but from an engineering perspective, virtually all polymers are interrelated.
Your example shows you don't know what your are talking about. Acrylic is a plastic. You can buy chunks of it from McMaster-Carr. It is dissolved in a solvent and sprayed on for paint, but what do you think happens when the solvent dissolves? The acrylic re-deposits to form a film, but it is still fundamentally the same material that is used to make those clear tumblers you can buy at Crate & Barrel.
Can you heat it up and cause the film to flow? Yes, but that just makes it a thermoplastic (as opposed to a thermoset). You could do the same thing with a polyethylene film. The difference with polyethylene is that the flow temperature is about 120C (250F), whereas Acrylic will flow at temperatures closer to 60C (150F).
All paint contains a lot of highly engineered polymers with adhesive properties. Thus, paint amounts to brush on (or spray on) plastic coatings.