A little crow- I did find a paper describing a one MILLION rpm turbine. That's the good news. The bad news is, like my prediction about the square and cube scaling laws, while it's really zippy, it dissipates THIRTEEN watts (in air friction mostly), and puts out exactly ZERO output power. So it seems you can have a small turbine, a high RPM turbine, or one that puts out significant power. But probably ony one of the above at a time.
>Efficiency in small devices is MEANINGLESS. What matters is power and energy density by volume and weight. This has both in spades.
Huh? We usually want something to come out of the turbine, usually mechanical power we can use to turn something , like a wheel or a generator. And efficiency is usually particularly welcome in portable devices, unless you like luggnig a bowling-ball tank of propane or somesuch on your wanderings.
Somehow I don't see any super up-side to this feature. Most people keep their eyes near the ground anyway, and don't have eyes in the back of their heads, so just keeping the surveillance camera between the sun and the target is going to be beacoup camo anyway.
Only things mising: blood, sweat, tears, and $$$$
on
IPv6 Essentials
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· Score: 2, Insightful
It's nice to sit in some aitr-conditioned office and write a book about how easy it is to get into IPV6.
And someday Britney will learn to sing and parent, and all rappers will go sign up as sunday-school superintendents.
In the meantime, the folks at the end of the ISP wires will have to spend kilo to megabucks on hardware and software upgrades, not to mention training themsleves, and training the users. Think of the millions of linksys home routers and wireless access points that will haev to be tossed out or reflashed! THink of all the books with xxx.xxx.xxx.xxx ip addresses that will be obsoleted! Lots of frustrated human-hours, even if the IP6 world will run as smoothly as the book suggests.
And efficiency drops very quickly with size-- you see friction goes down as the square of the size, while power goes down as the cube. Somewhere between the size of a sausage and a hot dog, all the turbine power is going into overcoming friction.
And the biz about 1 million RPM is pure hokum-- the worlds record is a bit below that, and that was with a tungsten alloy rotor in a vacuum chamber.
Methinks some press agent was drinking while on duty.
What's this common dread of "bacteria"? You have to look at the big picture. 97% of bacterial species have not the slightest ability to harm us. A typical surface has millions of these critters. Most of them are your friends, as they help crowd out the really bad varieties.
If you "disinfect" a surface, it's like clear-cutting a rain-forest. You've upset the balance, making a fresh new playground where the really baad and hardy weeds might take hold.
>Next, the point IS that EEStor has made improvements in ultracapacitors,
Hmmm, well I based my comments on the current state of the art. Which if you plot the progress over the years, on;y increases in performance about 20 to 30 percent a year, over the last 15 years.
Now they're fuzzily claiming they can get about 80 times the charge per pound, 180 times the $/charge.
Tis kind of jump has never happened in any kind of electronic technology. I remain skeptical.
>kWh per hour???
Yes. You'd like to charge the battery with a certain number of kWh. You'd like this to take a certain number of hours. The unit for this is kWh per hour.
Once the plane has done its zero-g fall, it has accelerated downwards at 9.8 m/s for a number of seconds. If it's a 20-second parabola, the plane will be going down at close to 200 m/s, that's almost 600 ft/sec. Real basic physics.
Now please explain how that plane is going to regain level flight without accelerating upwards? At 600 ft/sec down, yo don't have a whole lot of time to pull up. There's going to be significant G's pulled.
Er, Um, let's think a minute here. This article leaves out some very significant facts:
On Earth, gravity rules. And it plays a zero-sum game. Which means any time you spend at zero-G you spend a proportional amount of time 1/T at "T" G. So assuming this Euro "vomit comet" does 20 second weightless parabolas, there's immediately afterwards 20 seconds of TWO G, or fourty seconds of 1.5 G, or so on.
There's unlikely to ever be a need to do surgery in Earth orbit. Any reasonable orbiting craft will have a "down to Earth" capsule.
It's probably easier to dream up a.1 gravity rotatinal space station plan in order to make regular surgery, with liquids that don't float around, than to perfect zero-G surgery, in 20-second snatches.
Real surgery usually requires full anesthesia, which is hard enough to manage on Earth. Imagine trying to keep the patient from retching, vomiting, coughing, and keeping their airways clear of glop! I'd hate to have that job!
Otherwise up to the usual SD journalism by proxy standards.
Er, Um, all these comments, and nobody tried doing the math?
A capacitor bank to store that much charge (100 to 200 KwH) is going to cost, retail, at today's prices, oh, about $220,000 to $440,000 AND take up most of the space inside a minivan. . It's unlikely these folks have made that much of an improvement in cost and density.
That much energy stored in a capacitor bank will make Jerry Brukheimer really envious-- every such car out there will explode on impact.
Most houses are only wired for 100 to 200 amps at 120VAC, which scientists tell us, is only 24KwH per hour. Every house would have to be rewired from the power pole with wire two to five times as thick. And a fusebox and timer able to schedule your time sucking up the amps.
If EVERYBODY tried to do this, we'd need three to five times the available electic power. No way this can happen, there isnt that much available capital in the whole world to build that many power plants. And oh, those power plats would have to use nuclear or coal, not exactly "clean energy" in the broad view.
The F-14? A great plane? Maybe if you're 13, and seen in short-cut MTV-video style, with perky background music, interspersed with cuts to Kelly McGillis in a tight sweater. But as a *good* airplane, on the facts, it might not rate so wonderfully:
It had a horrible flight-to-maintenance hour figure, something like 40 hours of maintenance for each hour in the air.
The first engine for it had major problems with reliability and aerodynamic stalling. For many years neither the plane nor engine could be used to the edges of its intended flight envelope. And landing on a carrier with one engine is a major sweat-inducer.
Yes, it could go really fast, but not with any significant load of bombs or pods.
It predated stealth, so it was very radar-visible, even when as an afterthought, slathered with hundreds of pounds of ferrite paint. Its powerful radar also made it very visible to anyone with a fuzz-buster.
One of its most famous missions, hitting Khadaffi's tents, turned out to be less than glorious (not the plane's fault). The bombing of the Italian cafe, the "provocation", turned out to have nothing to do with Khadaffi.
Let's keep in mind:
(1) A survey of pantents shows somethng like 80% of patents could likely be successfully challenged on the basics: obviousness and prior art.
(2) Only about 3% of patents are ever licensed to others. Less than 1.5% of patents ever make any money for anyone but patent lawyers.
Okay, start with 9KW, peak, happening on a uncloudy day, at noon.
Now integrate that over all the daylight hours, taking into account the sun angle. That chops off at least half.
Then chop off the nightime hours, that subtracts another 40%
Then take into account all the cloudy or rainy or overcast hours. Another 30% off
Then take into account the losses charging and discharging the battery. Another 25% off.
Then take into account losses in the controller circuitry and motor. Subtract another 20%.
So that's 9KW times.5 times.6 *.7 *.6 *.8, or real close to 0.9KW, about 1.3 HP. Unlikely to make headway against the lightest of currents or winds.
>14x5 = 90 m^2. Efficiency 10% gives 9 m^2 effective. Solar influx is around 1kW/M^2. So this gives something like 9 kW peak, equating to about 12 hp.
Okay, let's do the math, all of it.
9KW is what you get when the sun is (1) Above the horizon. (2) Not obscured by clouds (3) directly overhead.
Looking at the design, the panel doesnt look steerable, as that would form a solid sail against the wind. It seems to have to lie flat. So it's only going to give 12hp at a small time around local noon, at the tropics. Quickly dropping on either side of noon, dropping to zero at night. So knock out 50% for nighttime, 35% for being off-perpendicular. You're down to about 3KW. But wait, there's more.
Now boats need to maintain headway against the waves 24 hrs a day, so to maintain headway they have to use batteries to store the energy, as mentioned in TFA.
Add a charging efficiency of 75% and a discharge efficiency of 70%, and the 85% effcicncy of a DC motor, and you get.... pretty darn close to my numbers! Down in the very very low horsepower-- hardly enough to fight a light current, much less a wind.
I'm surprised nobody's actually done the 9-line spreadsheet to calculate this out.
Let's assume, from the picture, they have a full 14 by say 5 meters of solar cells. If you do the math, starting from the number of watts of sun per square meter, the typical cell efficiency (when new and clean), the amount of sunlight, hmmm, the numbers are really dismal.
I get about 0.6 HORSEPOWER average over 24 hrs, 2.2 PEAK at noon. Unlikely to be able to budge the craft against even a light headwind or current.
Er, um, how's about a little bit of the scientific method?
IHMO it's unlikely the "ionic breeze" does much if anything useful here. Natural convection (remember "hot air rises"?) is probably the main heat-moving factor at work here.
A real simple test: unplug the ionic "cooler" and see how much the motherboard and CPU temperatures change. My guess, very little.
Well, that's really very touching faith in NASA. I know they have design principles that suggest one aim for designs that can continue running even under partial failure. That is a good thing. It's just that it's really very very basic-- a true short in a wire or winding is really really hard to survive. The shorted winding would tend to counter the work of the other windings, while drawing high eddy currents and overheating and/or melting. To survive with a shorted wire or winding, the motor would have to be designed with very high "leakage inductance", i.e. the coils would have to be weakly coupled to each other and to the rotor. Which makes for a very weak and inefficient motor.
I'm not saying they didnt or couldnt master this hard bit of technology, just considerably dubious.
A leveraged buyout is where one group of idiots with the gift of gab convinces another group of idiots with more money than sense, that the first group can better manage a company currently being run by a third group of idiots.
It's particularly silly in this case, as Motorola/Freescale has been often held up (perhaps even partially correctly) as an example of really good management. It's hard to stay in business for 50+ years with bad management.
The ideal case would be where the company *is* being run by clueless types. Or managers that emphasize long-term results versus quick cashouts. In those cases the blabby idiotsd can run the company into the ground and get lots of cash for a few years at least until all the cash cows have been milked dry.
>I bet that NASA has indeed engineered it so that the coolant motor continues to function with one shorted lead.
Would be nice. But even NASA can't change the laws of topology and physics:
A true "short" will blow a fuse or circuit breaker.
If it's a fuse and it blows, you're left with two hot wires, which due to toplology can only deliver one phase, and it will end up applied across two of the windings in series, and across all of the thrd winding.
That results in a totally unusable magnetic field-- no chance it can start rotating the motor from a standing stop, and very little chance it can keep it running.
If it's a circuit breaker, most 3-phase breakers have all three breakers mechanically ganged together, so if one phase trips they all do. Ergo no power to the motor.
But that's all academic as they've apparently launched anyway.
The computer didnt need rebooting, it was a problem in some Signal Conditioning Equipment.
They were getting screwy telemetry data downloaded. One of the guys on the ground remembered something similar from a practice run, and suggested this unorthodox maneuver.
>It is a short, in the power to the motor that pumps Freon coolant through the fuel cell.
Very dubious information!
I've never seen a "short" in one phase that didnt pop the three breakers.
>One part of the 3-phase power is shorted. The motor can still run with 2 phases left.
There's no such thing as "2-phase" power. You lose one phase, you're left with two wires, across which there's a single-phase of sqrt(3) of the voltage. And no, a 3-phase motor can't run with one phase.
There's very little likelyhood the lightning strike is directly connected to the fuel cell problem.
It's not a "short". Everything isnt a "short". A shorted fuel cell would be totally unusable.
NASA, now or then, can't replace the fuel cell without major trouble-- the whole thing has to be taken back to the assembly building, anything in the cargo bay has to be unloaded, the cargo bay floor has to be taken up-- major hassle. Not something that can be done on the Q.T.
The shuttle has *three* fuel cells, so it's not a major problem if one is acting a teensy bit unusual.
There are plenty of safety issues with *not* launching, parts tend to age quickly when out in the humid Florida sun. It's not clear that delaying launch is a ssafety improvement.
waay back at the very start of real "Wireless" communication, the transmitters were these hefty spark-gaps, often modulated by a spinning set of electrodes. And back then most houses had DC power, and unsteady power at that.
And each transmitter was hand-built, using rather rough tools.
All these things ensured that each signal had it's own quirks, in time, frequency, and temperature. Radio ops could often identify transmitters by thepaerticular yawps, swooshes, and zaps of the signal. ot to mention, identifing the morse code operator by his particular "fist", i.e. spacing and other personal quirks.
Then during WW2 our side started using spectrumanalyzers to categorize each model of German and Japanese radar. Here again each transmitter tended to have its own set of quirks.
Now, surprise, the same thing gets rediscovered. On some low level each wireless card has some (shuddrr) analog controlled oscillators, frequency dividers, duplexers, antennas, and amplifiers, each with it's own slight amplitude, frequency, and phase characteristics.
So nothing new here. Not by like, almost 100 years.
Slashdot Mirror
Deciding to move the company to selling on-line services is a *marketing* decision.
Either MicroSoft is really screwed up, or the article is a bit off base.
or both.
>Efficiency in small devices is MEANINGLESS. What matters is power and energy density by volume and weight. This has both in spades.
Huh? We usually want something to come out of the turbine, usually mechanical power we can use to turn something , like a wheel or a generator. And efficiency is usually particularly welcome in portable devices, unless you like luggnig a bowling-ball tank of propane or somesuch on your wanderings.
Somehow I don't see any super up-side to this feature. Most people keep their eyes near the ground anyway, and don't have eyes in the back of their heads, so just keeping the surveillance camera between the sun and the target is going to be beacoup camo anyway.
And someday Britney will learn to sing and parent, and all rappers will go sign up as sunday-school superintendents.
In the meantime, the folks at the end of the ISP wires will have to spend kilo to megabucks on hardware and software upgrades, not to mention training themsleves, and training the users. Think of the millions of linksys home routers and wireless access points that will haev to be tossed out or reflashed! THink of all the books with xxx.xxx.xxx.xxx ip addresses that will be obsoleted! Lots of frustrated human-hours, even if the IP6 world will run as smoothly as the book suggests.
The best large gas turbines do about 35%.
And efficiency drops very quickly with size-- you see friction goes down as the square of the size, while power goes down as the cube. Somewhere between the size of a sausage and a hot dog, all the turbine power is going into overcoming friction.
And the biz about 1 million RPM is pure hokum-- the worlds record is a bit below that, and that was with a tungsten alloy rotor in a vacuum chamber.
Methinks some press agent was drinking while on duty.
Finally, I can now sleep soundly, knowing the flaming torches on by web site are -fully legal- flaming torches.
If you "disinfect" a surface, it's like clear-cutting a rain-forest. You've upset the balance, making a fresh new playground where the really baad and hardy weeds might take hold.
Now they're fuzzily claiming they can get about 80 times the charge per pound, 180 times the $/charge.
Tis kind of jump has never happened in any kind of electronic technology. I remain skeptical. >kWh per hour??? Yes. You'd like to charge the battery with a certain number of kWh. You'd like this to take a certain number of hours. The unit for this is kWh per hour.
Once the plane has done its zero-g fall, it has accelerated downwards at 9.8 m/s for a number of seconds. If it's a 20-second parabola, the plane will be going down at close to 200 m/s, that's almost 600 ft/sec. Real basic physics.
Now please explain how that plane is going to regain level flight without accelerating upwards? At 600 ft/sec down, yo don't have a whole lot of time to pull up. There's going to be significant G's pulled.
Otherwise up to the usual SD journalism by proxy standards.
A capacitor bank to store that much charge (100 to 200 KwH) is going to cost, retail, at today's prices, oh, about $220,000 to $440,000 AND take up most of the space inside a minivan. . It's unlikely these folks have made that much of an improvement in cost and density.
That much energy stored in a capacitor bank will make Jerry Brukheimer really envious-- every such car out there will explode on impact.
Most houses are only wired for 100 to 200 amps at 120VAC, which scientists tell us, is only 24KwH per hour. Every house would have to be rewired from the power pole with wire two to five times as thick. And a fusebox and timer able to schedule your time sucking up the amps.
If EVERYBODY tried to do this, we'd need three to five times the available electic power. No way this can happen, there isnt that much available capital in the whole world to build that many power plants. And oh, those power plats would have to use nuclear or coal, not exactly "clean energy" in the broad view.
Let's keep in mind: (1) A survey of pantents shows somethng like 80% of patents could likely be successfully challenged on the basics: obviousness and prior art. (2) Only about 3% of patents are ever licensed to others. Less than 1.5% of patents ever make any money for anyone but patent lawyers.
Okay, start with 9KW, peak, happening on a uncloudy day, at noon. Now integrate that over all the daylight hours, taking into account the sun angle. That chops off at least half. Then chop off the nightime hours, that subtracts another 40% Then take into account all the cloudy or rainy or overcast hours. Another 30% off Then take into account the losses charging and discharging the battery. Another 25% off. Then take into account losses in the controller circuitry and motor. Subtract another 20%. So that's 9KW times .5 times .6 * .7 * .6 * .8, or real close to 0.9KW, about 1.3 HP. Unlikely to make headway against the lightest of currents or winds.
Okay, let's do the math, all of it.
9KW is what you get when the sun is (1) Above the horizon. (2) Not obscured by clouds (3) directly overhead.
Looking at the design, the panel doesnt look steerable, as that would form a solid sail against the wind. It seems to have to lie flat. So it's only going to give 12hp at a small time around local noon, at the tropics. Quickly dropping on either side of noon, dropping to zero at night. So knock out 50% for nighttime, 35% for being off-perpendicular. You're down to about 3KW. But wait, there's more.
Now boats need to maintain headway against the waves 24 hrs a day, so to maintain headway they have to use batteries to store the energy, as mentioned in TFA.
Add a charging efficiency of 75% and a discharge efficiency of 70%, and the 85% effcicncy of a DC motor, and you get.... pretty darn close to my numbers! Down in the very very low horsepower-- hardly enough to fight a light current, much less a wind.
Let's assume, from the picture, they have a full 14 by say 5 meters of solar cells. If you do the math, starting from the number of watts of sun per square meter, the typical cell efficiency (when new and clean), the amount of sunlight, hmmm, the numbers are really dismal.
I get about 0.6 HORSEPOWER average over 24 hrs, 2.2 PEAK at noon. Unlikely to be able to budge the craft against even a light headwind or current.
IHMO it's unlikely the "ionic breeze" does much if anything useful here. Natural convection (remember "hot air rises"?) is probably the main heat-moving factor at work here.
A real simple test: unplug the ionic "cooler" and see how much the motherboard and CPU temperatures change. My guess, very little.
I'm not saying they didnt or couldnt master this hard bit of technology, just considerably dubious.
It's particularly silly in this case, as Motorola/Freescale has been often held up (perhaps even partially correctly) as an example of really good management. It's hard to stay in business for 50+ years with bad management.
The ideal case would be where the company *is* being run by clueless types. Or managers that emphasize long-term results versus quick cashouts. In those cases the blabby idiotsd can run the company into the ground and get lots of cash for a few years at least until all the cash cows have been milked dry.
Home fridges do not have 3-phase motors.
>I bet that NASA has indeed engineered it so that the coolant motor continues to function with one shorted lead.
Would be nice. But even NASA can't change the laws of topology and physics:
- A true "short" will blow a fuse or circuit breaker.
- If it's a fuse and it blows, you're left with two hot wires, which due to toplology can only deliver one phase, and it will end up applied across two of the windings in series, and across all of the thrd winding.
- That results in a totally unusable magnetic field-- no chance it can start rotating the motor from a standing stop, and very little chance it can keep it running.
- If it's a circuit breaker, most 3-phase breakers have all three breakers mechanically ganged together, so if one phase trips they all do. Ergo no power to the motor.
But that's all academic as they've apparently launched anyway.The computer didnt need rebooting, it was a problem in some Signal Conditioning Equipment.
They were getting screwy telemetry data downloaded. One of the guys on the ground remembered something similar from a practice run, and suggested this unorthodox maneuver.
By comparison, Vandenberg or White Sands have LAND to the East, and much less equatorial boost.
Vandenberg is used mainly for spy satellites, which go into polar orbits, so the boost is not needed.
I've never seen a "short" in one phase that didnt pop the three breakers.
>One part of the 3-phase power is shorted. The motor can still run with 2 phases left.
There's no such thing as "2-phase" power. You lose one phase, you're left with two wires, across which there's a single-phase of sqrt(3) of the voltage. And no, a 3-phase motor can't run with one phase.
And each transmitter was hand-built, using rather rough tools.
All these things ensured that each signal had it's own quirks, in time, frequency, and temperature. Radio ops could often identify transmitters by thepaerticular yawps, swooshes, and zaps of the signal. ot to mention, identifing the morse code operator by his particular "fist", i.e. spacing and other personal quirks.
Then during WW2 our side started using spectrumanalyzers to categorize each model of German and Japanese radar. Here again each transmitter tended to have its own set of quirks.
Now, surprise, the same thing gets rediscovered. On some low level each wireless card has some (shuddrr) analog controlled oscillators, frequency dividers, duplexers, antennas, and amplifiers, each with it's own slight amplitude, frequency, and phase characteristics.
So nothing new here. Not by like, almost 100 years.