This technique doesn't cool anything, it prevents the tile from ever heating up in the first place. It has been in use for decades in gas turbines and rocket nozzles.
http://en.wikipedia.org/wiki/Turbine_blade#Cooling
You're thinking about this completely the wrong way. This is not actually cooling at all. They are injecting cold gas into the flow, against a positive pressure gradient. The pressure keeps the flow pressed against the surface of the craft, producing a protective film. The film prevents the craft from ever heating up in the first place. While this is a novel use of the technology, the technology itself is nothing new. It has been used for decades in rocket nozzles and gas turbines to protect the hot sections, and is a well understood and researched technique.
From first thoughts and glancing at the article, it seems the first use that comes to mind is for sound effects in movies and the like.
Generating realistic sounds of rigid objects is fairly straight forward. You know the material properties. You know the size and shape from your physics engine. You run it through some relatively simple set of equations to get the resonance frequency of the shard. Add in amplitude from the impact, natural damping over time, and you're done. Oh, but you have to do it for hundreds or thousands of objects, and each of those is impacting or fragmenting several times per second.
Producing realistic sound like that isn't very impressive. What is noteworthy is the optimization, generalization, and statistical modeling that they used to simplify that massive amount of computation into something that could be run in real-time on commodity hardware, rather than having to be backed by a supercomputer. Movie and special effects studios have those supercomputers and render farms at their disposal already. This work is intended to go hand and hand with the realistic and complex physics engines that games have started getting in the past few years.
And what about availability? Just like oil, there's only a limited quantity of U-233 and U-235 available on Earth. If that's used up, that's it!
Then you start using U-238, which is a hundred times more abundant than U-233 and U-235 combined. And then you start using up Th-232, which is several times more abundant than U-238.
What about the nuclear waste? Many countries using nuclear power still don't know where to put it, and probably won't for centuries to come. In the meantime the waste is "safe-deposited" in "interim storage facilities". That's a problem the entire nuclear industry hasn't solved since the inception of the nuclear industry.
No. It has been solved. Nearly all currently operating reactors are light water reactors, which require U-235, and produce lots of radioactive waste with a long half-life that must be stored. U-238 and Th-232 cycles reuse much of their waste internally. The unusable waste that is left is nearly all short half-life material, rendered safe within a few years to decades.
If we switch to reactors that can burn thorium and natural uranium, we have known quantity for tens of thousands of years of power. Hopefully, by that time, we will have found a replacement source or technology.
"Environuts" as you call them would have a lot less to complain about if corner-cutting bean counters hadn't been in charge of the currently running reactor base.
That in no way equates to them complaining less about the 'horrors of nuclear power'.
No it's not. Enriched uranium (U-235), used by current reactor technology, is somewhat rare, accounting for some 0.7% of all naturally occurring uranium. Breeder reactors can run on U-238, which accounts for nearly all of the remaining 99%, as well as Thorium-232, which is considerably more abundant than uranium. Breeder reactors would easily have enough fuel to last us tens of thousands of years at our current electrical consumption rates.
There are no guns in the DMZ. There are no troops in the DMZ. There is no military presence in the DMZ, hence making it demilitarized. The guns are put on the border to the DMZ, ensuring that there is nothing living in the DMZ.
North and South Korea have been in a state of war for the past 60 years. The two sides agreed to an armistice, pulling their lines back to 2km on either side of the 38th parallel. The 'demilitarized zone' is this 4km wide buffer zone between the two front lines, where no military forces are allowed to pass, under risk of restarting active conflict.
I always thought that it was a war crime to use robots in this fashion. It's great to keep people out of harms way when it's your people. But when the bots are on the other side it's a different story.
So you're saying when we do it, it's fine, but when any one else does it, that's a war crime? Do as I say, not as I do? By the way, we sided with South Korea on this one.
So your sure you may not NEED a 150kW electric motor, but when you don't have one your neighbour will just say, HA my trolleybus accelerates faster than your shitty little thing, and that is a very critical thing to consider when you make assumptions about where the power for such things will come from.
You do NEED good acceleration in a vehicle. Try getting onto the highway on a short on-ramp behind a Prius or Smart or similarly underpowered vehicle, and tell me otherwise. It's downright dangerous trying to merge with 65mph traffic when the putz in front of you hasn't even hit 40mph yet. I will admit, I see just as many large engined vehicles over on the shoulder after a failed merge as underpowered ones, but that's due to incompetent drivers and a worthless licensing system.
Electric motors are extremely efficient. You're looking at 90%+ efficiency over most of the operating range. A 150kW motor instead of a 50kW motor is only going to suffer a couple a couple percent. Throw in a few more percent due to increased rolling resistance from the extra weight and you're left with a slightly less efficient and considerably more usable vehicle.
The only reason we reached the moon was it served as a convenient, popular excuse to develop the tech necessary to nuke Moscow with an ICBM.
The only reason we reached the moon was Kennedy set it as a national goal, and had the good fortune to get himself shot at the height of his popularity. It was politically beneficial for subsequent administrations to rally behind the grandiose plans of the fallen hero.
If you covered the entire wing and fuselage with solar panels, you might get around 150kW out of it. That's 0.1% of the engine power at cruise. You probably wouldn't even provide enough thrust to offset the additional weight of the system, much less make it economical.
im kinda suprised they didnt make the wings longer from back to front, for more solar panel area.
Larger chord length would result in lower aspect ratio, higher induced drag, and lower efficiency. They could put propellers out on the wingtip to counter induced drag...
If they wanted to produce a useful airplane, they would probably use solar power to split water into hydrogen and oxygen on the ground, and use the hydrogen as fuel for some kind of jet/prop engine.
Then you would have to land to refill. The purpose of this kind of aircraft is that you can load it down with some electronics, radio, or other sensor package, and let it loiter over an area for months on end. Ideal for surveillance drones, atmospheric testing, flying cell transponders, etc...
You are above the clouds so you have a steady supply of power, but I dont know anything about the amount of energy a jet plane needs.
Going off some numbers for a (relatively old and inefficient) 747, you burn through ~5gal of kerosene per mile, at 550mph. That's about 6lbs of fuel per second, or around 120MW of thermal output. Using average efficiency available for commercial solar panels, you're looking at a half square kilometer array to power a single aircraft at cruise conditions. If you were to replace the turbine powered ducted fan engines for electric powered ones, you would cut that power consumption in about half.
No, it doesn't have tides, but it still has nearly constant flow of water through the Straight. Saltier, denser water sinks and constantly flows out to the open ocean at depth. Surface evaporation pulls new water into the Mediterranean. Tidal flows are only occasionally powerful enough to disrupt this flow, and then only during brief periods. There have been a number of proposals over the years to install undersea impellers to capture this energy.
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This technique doesn't cool anything, it prevents the tile from ever heating up in the first place. It has been in use for decades in gas turbines and rocket nozzles. http://en.wikipedia.org/wiki/Turbine_blade#Cooling
You're thinking about this completely the wrong way. This is not actually cooling at all. They are injecting cold gas into the flow, against a positive pressure gradient. The pressure keeps the flow pressed against the surface of the craft, producing a protective film. The film prevents the craft from ever heating up in the first place. While this is a novel use of the technology, the technology itself is nothing new. It has been used for decades in rocket nozzles and gas turbines to protect the hot sections, and is a well understood and researched technique.
From first thoughts and glancing at the article, it seems the first use that comes to mind is for sound effects in movies and the like.
Generating realistic sounds of rigid objects is fairly straight forward. You know the material properties. You know the size and shape from your physics engine. You run it through some relatively simple set of equations to get the resonance frequency of the shard. Add in amplitude from the impact, natural damping over time, and you're done. Oh, but you have to do it for hundreds or thousands of objects, and each of those is impacting or fragmenting several times per second.
Producing realistic sound like that isn't very impressive. What is noteworthy is the optimization, generalization, and statistical modeling that they used to simplify that massive amount of computation into something that could be run in real-time on commodity hardware, rather than having to be backed by a supercomputer. Movie and special effects studios have those supercomputers and render farms at their disposal already. This work is intended to go hand and hand with the realistic and complex physics engines that games have started getting in the past few years.
Is he the one who eats us with a dash of steak sauce?
And what about availability? Just like oil, there's only a limited quantity of U-233 and U-235 available on Earth. If that's used up, that's it!
Then you start using U-238, which is a hundred times more abundant than U-233 and U-235 combined. And then you start using up Th-232, which is several times more abundant than U-238.
What about the nuclear waste? Many countries using nuclear power still don't know where to put it, and probably won't for centuries to come. In the meantime the waste is "safe-deposited" in "interim storage facilities". That's a problem the entire nuclear industry hasn't solved since the inception of the nuclear industry.
No. It has been solved. Nearly all currently operating reactors are light water reactors, which require U-235, and produce lots of radioactive waste with a long half-life that must be stored. U-238 and Th-232 cycles reuse much of their waste internally. The unusable waste that is left is nearly all short half-life material, rendered safe within a few years to decades.
If we switch to reactors that can burn thorium and natural uranium, we have known quantity for tens of thousands of years of power. Hopefully, by that time, we will have found a replacement source or technology.
Oh come on... someone modded this interesting? All you have to do to prove the AC wrong is point toward that big glowing ball in the sky.
"Environuts" as you call them would have a lot less to complain about if corner-cutting bean counters hadn't been in charge of the currently running reactor base.
That in no way equates to them complaining less about the 'horrors of nuclear power'.
"Fissionable material" is somewhat rare.
No it's not. Enriched uranium (U-235), used by current reactor technology, is somewhat rare, accounting for some 0.7% of all naturally occurring uranium. Breeder reactors can run on U-238, which accounts for nearly all of the remaining 99%, as well as Thorium-232, which is considerably more abundant than uranium. Breeder reactors would easily have enough fuel to last us tens of thousands of years at our current electrical consumption rates.
There are no guns in the DMZ. There are no troops in the DMZ. There is no military presence in the DMZ, hence making it demilitarized. The guns are put on the border to the DMZ, ensuring that there is nothing living in the DMZ.
North and South Korea have been in a state of war for the past 60 years. The two sides agreed to an armistice, pulling their lines back to 2km on either side of the 38th parallel. The 'demilitarized zone' is this 4km wide buffer zone between the two front lines, where no military forces are allowed to pass, under risk of restarting active conflict.
I always thought that it was a war crime to use robots in this fashion. It's great to keep people out of harms way when it's your people. But when the bots are on the other side it's a different story.
So you're saying when we do it, it's fine, but when any one else does it, that's a war crime? Do as I say, not as I do? By the way, we sided with South Korea on this one.
So your sure you may not NEED a 150kW electric motor, but when you don't have one your neighbour will just say, HA my trolleybus accelerates faster than your shitty little thing, and that is a very critical thing to consider when you make assumptions about where the power for such things will come from.
You do NEED good acceleration in a vehicle. Try getting onto the highway on a short on-ramp behind a Prius or Smart or similarly underpowered vehicle, and tell me otherwise. It's downright dangerous trying to merge with 65mph traffic when the putz in front of you hasn't even hit 40mph yet. I will admit, I see just as many large engined vehicles over on the shoulder after a failed merge as underpowered ones, but that's due to incompetent drivers and a worthless licensing system.
Electric motors are extremely efficient. You're looking at 90%+ efficiency over most of the operating range. A 150kW motor instead of a 50kW motor is only going to suffer a couple a couple percent. Throw in a few more percent due to increased rolling resistance from the extra weight and you're left with a slightly less efficient and considerably more usable vehicle.
The only reason we reached the moon was it served as a convenient, popular excuse to develop the tech necessary to nuke Moscow with an ICBM.
The only reason we reached the moon was Kennedy set it as a national goal, and had the good fortune to get himself shot at the height of his popularity. It was politically beneficial for subsequent administrations to rally behind the grandiose plans of the fallen hero.
I've answered the phone as Satan, I've tried converting a telemarketer to Zoroasteranism, all great fun.
Your slashdot ID is such an appropriate number for that form of work.
If you covered the entire wing and fuselage with solar panels, you might get around 150kW out of it. That's 0.1% of the engine power at cruise. You probably wouldn't even provide enough thrust to offset the additional weight of the system, much less make it economical.
im kinda suprised they didnt make the wings longer from back to front, for more solar panel area.
Larger chord length would result in lower aspect ratio, higher induced drag, and lower efficiency. They could put propellers out on the wingtip to counter induced drag...
If they wanted to produce a useful airplane, they would probably use solar power to split water into hydrogen and oxygen on the ground, and use the hydrogen as fuel for some kind of jet/prop engine.
Then you would have to land to refill. The purpose of this kind of aircraft is that you can load it down with some electronics, radio, or other sensor package, and let it loiter over an area for months on end. Ideal for surveillance drones, atmospheric testing, flying cell transponders, etc...
You are above the clouds so you have a steady supply of power, but I dont know anything about the amount of energy a jet plane needs.
Going off some numbers for a (relatively old and inefficient) 747, you burn through ~5gal of kerosene per mile, at 550mph. That's about 6lbs of fuel per second, or around 120MW of thermal output. Using average efficiency available for commercial solar panels, you're looking at a half square kilometer array to power a single aircraft at cruise conditions. If you were to replace the turbine powered ducted fan engines for electric powered ones, you would cut that power consumption in about half.
A jet engine requires combustion.
No, a jet engine requires heat input. You can provide that heat in any manner you please, including electric resistance heating.
I'm not sure how you would get solar to work with a jet engine unless you switched over to a ducted fan type setup.
Nearly all jet engines in use are ducted fans.
Someone's precious snowflake will figure out a way to have the machine try and eat them, and they'll be shut down.
Fear and respect the escalator.... http://www.youtube.com/watch?v=5gwGcP8QbH8
Because this is not a switched protocol. It is a point-to-point serial data link using standard Cat6 cabling.
So I found it surprising that HDMI was a parallel cable spec!
HDMI is a serial cable spec. It consists of three independent serial data channels.
This is an observatory, but not a telescope. It's an omnidirectional particle detector, not pointed at some distant star.
No, it doesn't have tides, but it still has nearly constant flow of water through the Straight. Saltier, denser water sinks and constantly flows out to the open ocean at depth. Surface evaporation pulls new water into the Mediterranean. Tidal flows are only occasionally powerful enough to disrupt this flow, and then only during brief periods. There have been a number of proposals over the years to install undersea impellers to capture this energy.