I prefer www.heavens-above.com. He has better choices for satellite viewing and has Iridium Flare sighting information as well. Make sure you create an account so that you get info for your location.
That's right - stay the heck out of the Amateur radio bands! We've got specially-resonant pitchforks ready, just in case. 8-) The 433 MHz ISM band is supposedly available in region 2 only, which does not include the US. Also, it's not listed in CFR Title 47, Part 18.
Google around for papers by Dr. Eleanor Adair. She was an expert on RF exposure, and has done thousands of Simian and Human exposure tests as described in this NY Times Article. She claims to have personally tried every test before using it on her subjects, with no ill effects, ever. I tend to believe it, since the frequencies involved are 10^6 times lower than ionizing radiation that is proven dangerous.
The wayward satellite motor part came from an outdated PAM-D rocket engine that was once used to boost a satellite from low-Earth orbit a few hundred miles above Earth out to a geosynchronous position about 22,300 miles (36,000 km) above the planet. The debris was small, just 1/3 of an inch long, and was flying at about 19,800 mph, NASA officials said. The space station orbits the Earth at about 17,500 mph.
I was thinking about the DC side, not the AC side. My bad. The efficiency would be the same except that you'd have twice as many primary windings.
On the DC side, in a linear power supply any input voltage that exceeds the desired output voltage must be regulated in some sort of power sink such as a bipolar transistor or MOSFET (generally called a pass transistor). For example, if you look at the power dissipation curves for this integrated 5V regulator, you'll see that as the voltage across the regulator increases, the available output current decreases due to maxing out the thermal limits of the die.
I've never heard of a 10A circuit or receptacle. Many outlets in the US are supplied via a 20A branch circuit using #12 copper, but are wired with 15A receptacles. This is legal according to the NEC code. The remainder are supplied via a 15A branch circuit using #14 copper. The 15A receptacles have the typical 'I I' look to them. 20A receptacles look more like 'I- I' where the neutral blade has a Tee shape. A 20A plug has the neutral lead rotated 90 degrees, so it'll fit in a 20A receptacle but not a 15A one. Similarly, a 15A plug will mate with a 20A receptacle. This chart shows various NEMA plug and receptacle configurations.
I think he meant I^R losses in the premise wiring, not in the transmission lines. His point, though, is valid - for the same frequency (hence the same impedance), doubling the voltage will halve the current but quarter the power lost in distribution.
To your point re: 50 vs 60 Hz - I wonder how the additional transmission losses at 60Hz compare to the efficiency gain you get in the transformers at either end? Typically higher frequencies allow for smaller and more efficient transformers. It would be interesting to see where the sweet spot is for a given configuration. I'd guess it'd be closer to 400Hz, but that's just my guess.
Do you have independent circuit breakers on each end of the ring? If not, a break in the ring could lead to 4800W through one leg of the ring, leading to a fire.
Here in the states we have to worry about which phase a particular circuit is on, so the ring configuration would be difficult to do safely. The odds of hooking opposite phases in the ring would be unacceptably high, although the only result would be a pair of breakers that would refuse to stay on (perhaps sparking rather magnificently when closed).
240V is standard in the US - just ask your electric clothes dryer, oven, air conditioner, heat pump, water heater, etc.
Using 240V to power low demand items, especially things with cheap linear power supplies, leads to much more energy being wasted as heat in the regulating elements. Switching supplies fare better, however. For high demand items, the higher voltage means less loss in the wires supplying the equipment, and allows for smaller wires to boot, saving money on copper or aluminum.
Nearly all so called diesel locomotives are actually diesel-electric - the diesel engine turns a generator that supplies the power to drive the electric motors that make it move. The idea of having a battery bank on-board is not such an outrageous idea. In fact, there are hybrid locomotives that do just that.
On the main rail line on the East coast of the US, all train traffic south of Washington, DC is diesel-electric. Traffic in and north of DC is powered by overhead catenaries. They either run full-electric or electro-diesel combo engines.
Top fuel drag racing is all about the noise and noxious nitromethane fumes that make you cry. If you've never heard a top fuel dragster (or funny car) launch, you've not heard loud (shuttle/Saturn V launches and Krakatoa excepted, of course). So loud it makes you lungs vibrate. Startlingly loud. Barely-holding-my-fudge loud.
My main objection is that unless your atomizer is perfect, you may end up with retrograde-orbiting ice crystals of unusual size that are quite possibly more dangerous than the prograde debris you're trying to eliminate.
I mentioned that here. I didn't work out the B cross v of it, but it has promise. Note that even if the debris is accelerated away from the Earth, it still changes the eccentricity of its orbit so that it will dip into the atmosphere and decay.
Your article proves my point!!! That waste was generated by a once-thru reactor and is dangerous _because_ there is so much energy left in it! A once-thru reactor burns at most 1-2% of the available energy in the fuel. A fast neutron reactor would have burned up closer to 98% of the fuel, leaving waste that was dangerous for years, not thousands of years.
As I said, read up on modern fuel cycles - quit dragging Carter's idiotic one-thru legacy into discussions of the future of nuclear energy. An IFR could burn up 90+% of today's waste as fuel!
That would only work if the material were ferromagnetic, or at least highly diamagnetic or paramagnetic if you could generate an immense field (we're talking about yank-the-aircraft-carrier-into-orbit fields). Alas, most materials used in spacecraft are aluminum, titanium, or other non-ferromagnetic materials.
I intended for the ablation to provide enough momentum change for the particle to deorbit, not to lase it enough to eliminate it.
I would think your band of higher density would be dangerous, given that tiny particles of water have a nasty habit of sticking together and forming larger chunks (like a comet, say). Even by themselves, how much damage would a tiny retrograde water crystal do hitting a prograde satellite?
Without knowing the drag function on water vapor, it'd be hard to say how long it would stay up.
I like the idea of lofting a slowly-rotating honkin' aerogel disk many 100's of meters (or perhaps kilometers) in diameter. How cool would that be? You probably could see it from the Earth, and pay for it with advertisements on the disk! 8-(
As I noted, the only MASSLESS way would be photons, which electrons, etc aren't. New paragraph, new idea. I mentioned the others since there are already great gobs of them flying around every time the sun decides to burp. They would quickly be channeled toward the poles by the Earth's magnetic field and be quickly eliminated as a hazard.
Not only would lofting water into space be a colossal waste of energy and water, it would only exacerbate the problem!
IMHO the only 'clean' way to deorbit debris is to add energy to the debris in the retrograde direction without using additional mass, which means photons. Laser pulses could do it either by radiation pressure directly (huge laser), or by pulses that ablate the debris slightly (creates tiny beads of additional debris).
Electron/proton beams would work as well, as would alpha particles, but they'd pose a risk to humans in space. In fact, using charged particles might induce a charge on the debris that would then help direct the debris toward it's doom (debris vector, Earth's magnetic field, right hand rule....whatever).
It seems to me that you haven'treadanypapers on breeder technology. Waste from a breeder is not 'hot' for 10,000 years - the point of burning up the long half life actinides is to eliminate them from the waste stream, making what little waste there is very hot for a very short time. That's how radiation works - things are either very hot for a short time or moderately hot for a long time.
You realize that all of the nuclear waste in the US today is stored on-site in casks either _in the open_ or in a shallow pool of water?
I would suggest you read up on modern reactor technology (and existing, proven technology that Clinton canned like the IFR) before you rehash arguments based on information from the 1950's.
Explain that to people who have their laptops seized at the border and have been arrested for child porn for images that were in their browser's cache directory. The user may have never even seen those images if their browser decided to 'helpfully' preload linked pages and images for speed, or if a site dymanically loaded the image (web 2.0, I'm talking about you), or if their AV software did it.
Authoritarian measures 'for the children' always stomp on rationality.
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I prefer www.heavens-above.com. He has better choices for satellite viewing and has Iridium Flare sighting information as well. Make sure you create an account so that you get info for your location.
That's right - stay the heck out of the Amateur radio bands! We've got specially-resonant pitchforks ready, just in case. 8-) The 433 MHz ISM band is supposedly available in region 2 only, which does not include the US. Also, it's not listed in CFR Title 47, Part 18.
There's an exception for Part 15 devices to use 433-434 MHz, but that's for shipping container ID devices only.
Google around for papers by Dr. Eleanor Adair. She was an expert on RF exposure, and has done thousands of Simian and Human exposure tests as described in this NY Times Article. She claims to have personally tried every test before using it on her subjects, with no ill effects, ever. I tend to believe it, since the frequencies involved are 10^6 times lower than ionizing radiation that is proven dangerous.
It's Mother-pus-bucket, of course.
Here's a picture of a PAM-D motor.
I was thinking about the DC side, not the AC side. My bad. The efficiency would be the same except that you'd have twice as many primary windings.
On the DC side, in a linear power supply any input voltage that exceeds the desired output voltage must be regulated in some sort of power sink such as a bipolar transistor or MOSFET (generally called a pass transistor). For example, if you look at the power dissipation curves for this integrated 5V regulator, you'll see that as the voltage across the regulator increases, the available output current decreases due to maxing out the thermal limits of the die.
And affix a new set of tires.
Roger that on the dangers of high short circuit current and moderately high voltages. Look for videos of Arc Flash to see how deadly it can be.
I've never heard of a 10A circuit or receptacle. Many outlets in the US are supplied via a 20A branch circuit using #12 copper, but are wired with 15A receptacles. This is legal according to the NEC code. The remainder are supplied via a 15A branch circuit using #14 copper. The 15A receptacles have the typical 'I I' look to them. 20A receptacles look more like 'I- I' where the neutral blade has a Tee shape. A 20A plug has the neutral lead rotated 90 degrees, so it'll fit in a 20A receptacle but not a 15A one. Similarly, a 15A plug will mate with a 20A receptacle. This chart shows various NEMA plug and receptacle configurations.
I think he meant I^R losses in the premise wiring, not in the transmission lines. His point, though, is valid - for the same frequency (hence the same impedance), doubling the voltage will halve the current but quarter the power lost in distribution.
To your point re: 50 vs 60 Hz - I wonder how the additional transmission losses at 60Hz compare to the efficiency gain you get in the transformers at either end? Typically higher frequencies allow for smaller and more efficient transformers. It would be interesting to see where the sweet spot is for a given configuration. I'd guess it'd be closer to 400Hz, but that's just my guess.
Do you have independent circuit breakers on each end of the ring? If not, a break in the ring could lead to 4800W through one leg of the ring, leading to a fire.
Here in the states we have to worry about which phase a particular circuit is on, so the ring configuration would be difficult to do safely. The odds of hooking opposite phases in the ring would be unacceptably high, although the only result would be a pair of breakers that would refuse to stay on (perhaps sparking rather magnificently when closed).
240V is standard in the US - just ask your electric clothes dryer, oven, air conditioner, heat pump, water heater, etc.
Using 240V to power low demand items, especially things with cheap linear power supplies, leads to much more energy being wasted as heat in the regulating elements. Switching supplies fare better, however. For high demand items, the higher voltage means less loss in the wires supplying the equipment, and allows for smaller wires to boot, saving money on copper or aluminum.
Nearly all so called diesel locomotives are actually diesel-electric - the diesel engine turns a generator that supplies the power to drive the electric motors that make it move. The idea of having a battery bank on-board is not such an outrageous idea. In fact, there are hybrid locomotives that do just that.
On the main rail line on the East coast of the US, all train traffic south of Washington, DC is diesel-electric. Traffic in and north of DC is powered by overhead catenaries. They either run full-electric or electro-diesel combo engines.
Top fuel drag racing is all about the noise and noxious nitromethane fumes that make you cry. If you've never heard a top fuel dragster (or funny car) launch, you've not heard loud (shuttle/Saturn V launches and Krakatoa excepted, of course). So loud it makes you lungs vibrate. Startlingly loud. Barely-holding-my-fudge loud.
No, it's more like fighting fire with gasoline.
My main objection is that unless your atomizer is perfect, you may end up with retrograde-orbiting ice crystals of unusual size that are quite possibly more dangerous than the prograde debris you're trying to eliminate.
I mentioned that here. I didn't work out the B cross v of it, but it has promise. Note that even if the debris is accelerated away from the Earth, it still changes the eccentricity of its orbit so that it will dip into the atmosphere and decay.
Your article proves my point!!! That waste was generated by a once-thru reactor and is dangerous _because_ there is so much energy left in it! A once-thru reactor burns at most 1-2% of the available energy in the fuel. A fast neutron reactor would have burned up closer to 98% of the fuel, leaving waste that was dangerous for years, not thousands of years.
As I said, read up on modern fuel cycles - quit dragging Carter's idiotic one-thru legacy into discussions of the future of nuclear energy. An IFR could burn up 90+% of today's waste as fuel!
Did they put the lotion on their skin?
Seriously, that's just appalling. /me shivers...
English doesn't have a decent plural for 'it' - 'they/their' just don't cut it as the plural for "It puts the lotion on its skin."
That would only work if the material were ferromagnetic, or at least highly diamagnetic or paramagnetic if you could generate an immense field (we're talking about yank-the-aircraft-carrier-into-orbit fields). Alas, most materials used in spacecraft are aluminum, titanium, or other non-ferromagnetic materials.
I intended for the ablation to provide enough momentum change for the particle to deorbit, not to lase it enough to eliminate it.
I would think your band of higher density would be dangerous, given that tiny particles of water have a nasty habit of sticking together and forming larger chunks (like a comet, say). Even by themselves, how much damage would a tiny retrograde water crystal do hitting a prograde satellite?
Without knowing the drag function on water vapor, it'd be hard to say how long it would stay up.
I like the idea of lofting a slowly-rotating honkin' aerogel disk many 100's of meters (or perhaps kilometers) in diameter. How cool would that be? You probably could see it from the Earth, and pay for it with advertisements on the disk! 8-(
As I noted, the only MASSLESS way would be photons, which electrons, etc aren't. New paragraph, new idea. I mentioned the others since there are already great gobs of them flying around every time the sun decides to burp. They would quickly be channeled toward the poles by the Earth's magnetic field and be quickly eliminated as a hazard.
Not only would lofting water into space be a colossal waste of energy and water, it would only exacerbate the problem!
IMHO the only 'clean' way to deorbit debris is to add energy to the debris in the retrograde direction without using additional mass, which means photons. Laser pulses could do it either by radiation pressure directly (huge laser), or by pulses that ablate the debris slightly (creates tiny beads of additional debris).
Electron/proton beams would work as well, as would alpha particles, but they'd pose a risk to humans in space. In fact, using charged particles might induce a charge on the debris that would then help direct the debris toward it's doom (debris vector, Earth's magnetic field, right hand rule....whatever).
It seems to me that you haven't read any papers on breeder technology. Waste from a breeder is not 'hot' for 10,000 years - the point of burning up the long half life actinides is to eliminate them from the waste stream, making what little waste there is very hot for a very short time. That's how radiation works - things are either very hot for a short time or moderately hot for a long time.
You realize that all of the nuclear waste in the US today is stored on-site in casks either _in the open_ or in a shallow pool of water?
I would suggest you read up on modern reactor technology (and existing, proven technology that Clinton canned like the IFR) before you rehash arguments based on information from the 1950's.
Explain that to people who have their laptops seized at the border and have been arrested for child porn for images that were in their browser's cache directory. The user may have never even seen those images if their browser decided to 'helpfully' preload linked pages and images for speed, or if a site dymanically loaded the image (web 2.0, I'm talking about you), or if their AV software did it.
Authoritarian measures 'for the children' always stomp on rationality.