The poor power factor is caused by harmonic distortion, not phase displacement. Phase compensation capacitors don't fix that problem. One CFL doesn't create enough distortion current worry about, but when all the lamps in the house are CFLs it's noticeable, and when every house on the block converts to CFLs there's likely to be trouble. Harmonic current causes disproportionately high losses in distribution transformers, because the proximity effect losses are dramatically higher at the harmonic frequencies. Even though the current is "only" twice what you'd expect for a 13W lamp, the losses in the transformer are higher than that current suggests. There should still be a net energy savings, but having a large percentage of the load be high distortion devices does over-work some parts of the power system. Many office buildings had damage and even fires when PCs were adopted in large numbers. The rated load "watts" appeared to be safe, but the high harmonic current over-heated neutral conductors and supply transformers. This led to electrical code changes for full-size (or larger) neutral conductors, and to requirements forK-rated power distribution transformers.
Before, 1500 Staples employees knew who he was, that he was terminated, and the reason cited by Staples for doing so. Now, millions do. That certainly won't help him find a new position!
That's so very true! Microsoft's past success has become their present burden. They can't remove a function that worked in the last version without some customers calling it "broken". The first Windows release had to support DOS programs, and that means drive letters and back-slash directory separators. It then went into Windows 2, then 3, on through 95, 98, and ME. NT had different (non-DOS) underpinnings, but still had a "DOS shell" for compatibility and still supported drive letters and backslashes. Thus the legacy lives on in 2000, XP, Vista, and on to Windows 7.
It's a lesson that every engineer and programmer eventually learns: be careful what you release today, because you'll be living with that decision ten years from if the product succeeds, and you'll have to put it on your resume if it doesn't!
I'm not saying MS is perfect, nobody is. I do appreciate how difficult a job they have trying to update a product with so long a history and so large a customer base. That's the biggest difference between the established incumbent and the start-ups who challenge them: the new players lack long-time customers, so they don't worry about losing them.
Colorado PBS affiliate KBDI can't delay. Their analog transmitting antenna was badly damaged, and it's not worth the cost to fix it for a few more months' service even if they had the money (and like most PBS stations, they don't have much to spend). Besides that, repairs on that mountain really should wait until the weather improves--which isn't likely until May. Such is life when the antenna is at 11,500 feet!
If you're using a standard connector, use it as intended! A "USB type B" connector should only be 5V, should not exceed the current ratings, etc. If the device being charged is built per the USB slave specs:
- Any USB connector is a suitable power supply for recharging.
- You don't need a special chip, nor a special charger.
- The USB connector is used in a 100% standard way, so there is no risk of damaging another USB device by attaching it to the charger instead of the PC.
- A standard battery charger IC can handle the job at less cost.
- Using standard USB for charging has already been proposed in China.
Truth is an absolute defense to libel. In the US, that's generally true. But it's not the same everywhere, nor for every person and entity. Even if you're "in the right", being involved in a defamation action can be brutal. For a semi-fictional, semi-autobiographical account of this, read Uris' QB VII.
If it's a valid predictor, it would produce those results based only on citations before the author receives a Nobel nomination. An author known to be a Nobel nominee, and especially a Nobel prize winner, will receive more citations and page reads based on their Nobel notoriety. An author who fails to cite a Nobel winning paper would be considered to have incomplete references, and the referees or thesis committee will tell them to add those missing citations.
No, not kidding. Like many technical regulations, the cost and expertise required is considerable and the government has little desire to be involved (and less funding). Some large companies can afford to run their own test labs with the necessary equipment and training, but most don't. If you don't have a steady stream of testing, expensive gear is left sitting idle and the test techs' expertise grows stale. That's why independent testing labs are in business: you hire a reputable, qualified lab to do the testing, and you attest that the product is compliant (or more commonly, go back and fix it, then test it gain). The FCC does not test most equipment (radio transmitters being the main exception), the makers are responsible for that. In Europe even your product safety approval is self-certified: an outside lab is probably doing the testing, but it's your responsibility to be sure it's done properly. Frankly, it's an improvement over the old bureaucratic ways: needing an Official Government Test for every jurisdiction was expensive and maddeningly slow. That has mostly been done away with as an artificial trade barrier, and rightly so!
Of course in that $1,500 won't buy them what it would buy them now. You got that right! Like any subsidy, it will increase prices. The demand for used cars will increase, and the supply will decrease (the entire point of this proposal is to permanently remove large numbers of used cars from service). The market price goes up, just like the Econ 101 textbook says it would.
There _may_ be environmental benefits as people dump less fuel efficient cars for already existing more fuel efficient cars... The article said the program would be $2B per year. At an average $3K subsidy, that would cover less than a million cars per year. It sounds like a lot, but it comes to about 1/3 of 1% of the cars registered in the US. In other words, the difference it makes will be too small make a noticeable difference.
This reminds me of a proposal one of the car magazines published many years ago. They said that compared to the cost and effects of tightening pollution laws for new cars, we could achieve more pollution control at less cost by trading owners of old, highly polluting cars a brand new Cadillac for their old stink-bomb clunkers.
The presidential planes certainly have grown through he years! Eisenhower's plane was a Lockheed Constellation (on display at the Pima Air Museum in Tucson). It's downright cramped compared to even a B737 or A320. Perhaps bigger concerns in this era of globe-trotting politicians are range and the number of airports it can use. Both the B747-8 and the A380 have long cruising ranges, but both are also limited to the largest airports with the longest runways. It's time to forget about having the biggest and best, and think about the most practical replacement for Air Force One. On the bright side, they accumulate less flying hours and flight cycles than they would in airline service, so they're likely in better shape than age suggests.
Wouldn't the service station still need to collect the federal gas tax? There would be two completely different systems at work, trying to accomplish essentially the same goal (collecting highway taxes). Government efficiency at its finest!
They don't generate heat as such, but AC->DC conversion does...
LEDs do generate heat as such, but less than an incandescent bulb. Low power LED indicators don't make much heat because they are low power (10-100mW), but high brightness LED arrays for room lighting usually require heat sinks to keep the junctions at a safe operating temperature.
The CFL ballast performs both an AC to DC conversion (at 50-60Hz) and a DC to AC inversion (at 20kHz or higher). The fluorescent tube uses AC, so the discharge current can be limited by an inductor. The higher AC frequency means the inductor can be very small compared to a line-frequency ballast with a big iron core.
There are some nice ICs designed for HF ballast applications, offering improved performance and protection functions. You won't find them in low cost CFLs. Every circuit shown on that page is a two transistor self-oscillating inverter. There is no output regulation, there is no power factor correction, some lack RFI filtering, some even omit the fuse or fusible resistor. If low cost LED lamps become available, expect them to also use the cheapest possible solution!
A 12V car charger will do nicely. Most phones come with one, and even if yours doesn't they're widely available and don't cost much. The charger is low current, so you don't need to run the engine while charging.
The bigger concern is the cell company's infrastructure. I can't believe they fought the FCC's run time and maintenance requirements. Because the cell phone system is part of the 9-1-1 communications infrastructure, I'd expect at a minimum NFPA 110 Class 24, level 2 compliance (24 hours run-time before refueling).
Batteries would have higher loss than that giant ceramic capacitor in regenerative braking systems. Even at very slow charge and discharge rates, the best you can expect from a battery is about 90% efficiency. At the high rates needed for braking and acceleration, it's considerably lower. Charge voltage is higher than the discharge voltage in a storage battery, and by more just than the IxR resistive losses. If you trace the terminal voltage vs. charge (Coulombs) for charge/discharge cycle, the path traces a hysteresis loop. The area enclosed by that loop is the energy loss.
On the other hand, a big drawback for this giant capacitor is the high operating voltage (3.5kV, per the patent). Power electronic systems for that voltage are expensive and difficult to build. The voltage drops considerably during discharge: getting 75% of the energy out of the cap means operating to half the peak voltage, and at twice the current required at full bus voltage. That, too, makes electronics more expensive for the same power output.
The 375V battery in the Tesla Roadster allows use of parts marketed for 240Vac line applications, which are sold in high volumes and therefore competitively priced. The question is whether the benefits of the capacitor (reduced size and weight) justify the more expensive electronics.
"*** Not measured -- arcing hazard too great at close separation." In this case, "close separation" means 4m away, so don't put this in your room. Forget about RF radiation, worry about the fire hazard!
No, C1 is a "type X" capacitor connected from line (L) to neutral (N), with only the input fuse between the cap and the power cord. C1 is a differential mode noise filter, and presents a badly mismatched termination to the BPL signals on the L-N wire pair.
Your reasoning does apply to C3 and C11, much smaller "type Y" caps connected from the rectifier output to ground (E, "Earth"). The combination of less capacitance, common mode chokes L2 and L3, and ferrite bead L1 means that C3 and C11 won't significantly influence signals sent over the power line.
There is a bleeder, but it's not obvious from the schematic. U1 draws some supply current through its "D" pin, and various other resistor strings (R3-R4 and R7-R8-R9) bleed off a bit more current. There's not a lot of bleed current by design: you have to keep it low to meet the Energy Star efficiency and stand-by power limits, and you need to meet them to sell products in California (among other places). The charge on C2 isn't available at the line cord, because the bridge rectifier blocks the reverse current flow. So a discharge time measured in minutes is fine for that part of the circuit.
What is important is to discharge C1, which is where R1-R2 come into play. Those are sized to waste as little power as possible, while still meeting the safety requirements for discharging C1 to a safe level quickly after disconnecting the AC line plug.
There are more issues that make RF communications on power lines very difficult. Growing numbers of devices plugged into the AC line generate RF noise, which must be controlled to meet FCC regulations (and overseas equivalents). Manufacturers of switch-mode power supplies include filtering to meet those requirements. That means there's a filter cap lurking inside, shorting out BPL signal on the power line (in this typical example, it's C1). Every time you plug in another device, the AC line transmission path is further compromised.
The state-of-the-art power supply designs also use "spread-spectrum" clocks, to distribute the noise over as much bandwidth as possible. That reduces the power at any one frequency to ease the RFI filter requirements, but does so by moving noise power to what would have been quiet spots between the noise peaks of a fixed-frequency clock. In other words, the BPL system can't choose a quiet operating frequency, because there are none. See figure 3 of the previous example. At frequencies above 2MHz, the individual clock harmonics blur together. The emissions are 10dB or more below the legal limit at the peaks, but aren't very much lower between them. This is frequency spreading at work.
Now imagine such devices being attached to every light fixture in the house (modern CFLs and LED lamps both use switch-mode technology). Getting a signal from the utility system to a household outlet will become increasingly difficult. BPL is not a good fit for the modern household.
If the device being interfered with has a "CE" mark, that means it's supposed to pass several IEC RF immunity tests. Recent changes have added higher frequencies to the test, to address the operating frequencies of newer cell phones etc. The performance levels for consumer-grade equipment aren't especially high, but are much better than nothing at all. 2W radiated from a cell phone should not exceed the test level (3V/m) at 3m distance from the antenna. So equipment in the next room should be OK, but anything within arm's reach of the phone user is in a much stronger field and likely to be interfered with.
...there's the reputation effect of guest authorship where having a well-known, senior, academic's name on the paper helps it through no matter how absurd the findings.
There's an antidote for that: blind reviews, where the authors' names and affiliations are removed from the review copies. Even the cited references can be removed, because authors are more inclined to cite papers from their own department than those of competitors. It's not a perfect solution; you can still see the authors' writing style, terminology, etc. and in many cases that's enough to identify the papers' origins. But it does help the reviewers to rate the papers more on their quality, and less on the reputation of the author and research lab that produced them.
Wasn't platform independence the selling point of UCSD's p-system? Yes, it worked, but it never really caught on. One camp of software development says that hardware is always getting faster, cheaper and more efficient, so adding a layer of abstraction between the source code and the hardware is not a problem. The other camp says we can use those same performance improvements to build software that does more things, on larger data sets, with better graphics, and in general make what once were impractically large and complex software tasks run on the average users' systems. Over the last three decades, the market has favored the latter.
The economy benefit comes from engine braking being s-l-o-w, so you learn to get off the throttle sooner. It doesn't matter if you turn kinetic energy into hot brake rotors via friction or hot air via compression, either way it's disposed of (OK, maybe 30% gone if you have a hybrid or EV with regenerative brakes). Using engine braking discourages you from charging up to the red light under power, then braking hard only when you must. Downshifts don't save fuel, you can get the same savings by braking early and very gently to stop in the same distance as you would with engine braking. They just teach you to plan ahead and make better use of the energy you expended accelerating up to speed.
Engine braking is the way to go for descents in the mountains, even with an automatic transmission (it has PRNDL for a reason). Besides keeping the friction brakes cooler, not riding the pedal constantly makes the brake lights meaningful to the driver behind you. If the brake lights are always on, they are just as useless as if they don't work at all.
Yes there still are NiCd batteries on the market, but they aren't popular for applications where NiMH batteries meet the needs. NiMH usually gives more A-Hrs in the same package compared to NiCd, at a comparable price. But NiCd is better for high peak current, cold weather use, is more tolerant of overcharge, and less toxic when it's disposal time. They're still sold in the US, but the RoHS regulations have banned them in most products sold in Europe.
No, there's no open season on fleeing fugitives. You can't shoot them unless they're an immediate threat and you reasonably believe that anything less would be inadequate to stop that threat, or if they have illegally entered your house and you have reason to believe they intend to harm you or commit a crime. Colorado's self-defense laws don't allow you to shoot somebody who's running away. Ignore the hype, "Make my day!" vigilante action is illegal here.
It's like a usenet flame-war, or a telemarketer. If you continue to respond, it only encourages them to continue the exchange.
Give them one polite response, maybe two if you're feeling generous. After that, ignore their posts. Deny them the satisfaction of harassing you. If their posts continue or worsen, expel them from the forum. It's your site, and you set and enforce the acceptable use policy for your forum. If you don't have an AUP posted for your site (I can't tell; you just slashdotted your own site!) then the first step is obvious.
Second, NEC ampacity standards are for tolerable voltage drop, not wire overheating. A 200A-rated line will actually carry a lot more than 200A.
That is backwards! The NEC ampacity tables (310.16, 310.17, etc.) are concerned with conductor heating. That's why there are:
Separate columns for different wire temperature ratings
Reduction factors for higher than normal ambient temperatures
Different tables for single conductors and multiple conductors in a raceway or cable
Adjustment factors for more than three current-carrying conductors in the same raceway or cable
The only exceptions to the temperature-based ratings are for 15A, 20A, and 30A circuits. In most installations these must use at least 14AWG, 12AWG and 10AWG conductors (respectively), even if the Section 310 tables otherwise permit a smaller conductor.
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The poor power factor is caused by harmonic distortion, not phase displacement. Phase compensation capacitors don't fix that problem. One CFL doesn't create enough distortion current worry about, but when all the lamps in the house are CFLs it's noticeable, and when every house on the block converts to CFLs there's likely to be trouble. Harmonic current causes disproportionately high losses in distribution transformers, because the proximity effect losses are dramatically higher at the harmonic frequencies. Even though the current is "only" twice what you'd expect for a 13W lamp, the losses in the transformer are higher than that current suggests. There should still be a net energy savings, but having a large percentage of the load be high distortion devices does over-work some parts of the power system. Many office buildings had damage and even fires when PCs were adopted in large numbers. The rated load "watts" appeared to be safe, but the high harmonic current over-heated neutral conductors and supply transformers. This led to electrical code changes for full-size (or larger) neutral conductors, and to requirements forK-rated power distribution transformers.
Before, 1500 Staples employees knew who he was, that he was terminated, and the reason cited by Staples for doing so. Now, millions do. That certainly won't help him find a new position!
That's so very true! Microsoft's past success has become their present burden. They can't remove a function that worked in the last version without some customers calling it "broken". The first Windows release had to support DOS programs, and that means drive letters and back-slash directory separators. It then went into Windows 2, then 3, on through 95, 98, and ME. NT had different (non-DOS) underpinnings, but still had a "DOS shell" for compatibility and still supported drive letters and backslashes. Thus the legacy lives on in 2000, XP, Vista, and on to Windows 7.
It's a lesson that every engineer and programmer eventually learns: be careful what you release today, because you'll be living with that decision ten years from if the product succeeds, and you'll have to put it on your resume if it doesn't!
I'm not saying MS is perfect, nobody is. I do appreciate how difficult a job they have trying to update a product with so long a history and so large a customer base. That's the biggest difference between the established incumbent and the start-ups who challenge them: the new players lack long-time customers, so they don't worry about losing them.
Colorado PBS affiliate KBDI can't delay. Their analog transmitting antenna was badly damaged, and it's not worth the cost to fix it for a few more months' service even if they had the money (and like most PBS stations, they don't have much to spend). Besides that, repairs on that mountain really should wait until the weather improves--which isn't likely until May. Such is life when the antenna is at 11,500 feet!
If you're using a standard connector, use it as intended! A "USB type B" connector should only be 5V, should not exceed the current ratings, etc. If the device being charged is built per the USB slave specs:
- Any USB connector is a suitable power supply for recharging.
- You don't need a special chip, nor a special charger.
- The USB connector is used in a 100% standard way, so there is no risk of damaging another USB device by attaching it to the charger instead of the PC.
- A standard battery charger IC can handle the job at less cost.
- Using standard USB for charging has already been proposed in China.
Truth is an absolute defense to libel. In the US, that's generally true. But it's not the same everywhere, nor for every person and entity. Even if you're "in the right", being involved in a defamation action can be brutal. For a semi-fictional, semi-autobiographical account of this, read Uris' QB VII.
If it's a valid predictor, it would produce those results based only on citations before the author receives a Nobel nomination. An author known to be a Nobel nominee, and especially a Nobel prize winner, will receive more citations and page reads based on their Nobel notoriety. An author who fails to cite a Nobel winning paper would be considered to have incomplete references, and the referees or thesis committee will tell them to add those missing citations.
No, not kidding. Like many technical regulations, the cost and expertise required is considerable and the government has little desire to be involved (and less funding). Some large companies can afford to run their own test labs with the necessary equipment and training, but most don't. If you don't have a steady stream of testing, expensive gear is left sitting idle and the test techs' expertise grows stale. That's why independent testing labs are in business: you hire a reputable, qualified lab to do the testing, and you attest that the product is compliant (or more commonly, go back and fix it, then test it gain). The FCC does not test most equipment (radio transmitters being the main exception), the makers are responsible for that. In Europe even your product safety approval is self-certified: an outside lab is probably doing the testing, but it's your responsibility to be sure it's done properly. Frankly, it's an improvement over the old bureaucratic ways: needing an Official Government Test for every jurisdiction was expensive and maddeningly slow. That has mostly been done away with as an artificial trade barrier, and rightly so!
Of course in that $1,500 won't buy them what it would buy them now. You got that right! Like any subsidy, it will increase prices. The demand for used cars will increase, and the supply will decrease (the entire point of this proposal is to permanently remove large numbers of used cars from service). The market price goes up, just like the Econ 101 textbook says it would.
There _may_ be environmental benefits as people dump less fuel efficient cars for already existing more fuel efficient cars... The article said the program would be $2B per year. At an average $3K subsidy, that would cover less than a million cars per year. It sounds like a lot, but it comes to about 1/3 of 1% of the cars registered in the US. In other words, the difference it makes will be too small make a noticeable difference.
This reminds me of a proposal one of the car magazines published many years ago. They said that compared to the cost and effects of tightening pollution laws for new cars, we could achieve more pollution control at less cost by trading owners of old, highly polluting cars a brand new Cadillac for their old stink-bomb clunkers.
The presidential planes certainly have grown through he years! Eisenhower's plane was a Lockheed Constellation (on display at the Pima Air Museum in Tucson). It's downright cramped compared to even a B737 or A320. Perhaps bigger concerns in this era of globe-trotting politicians are range and the number of airports it can use. Both the B747-8 and the A380 have long cruising ranges, but both are also limited to the largest airports with the longest runways. It's time to forget about having the biggest and best, and think about the most practical replacement for Air Force One. On the bright side, they accumulate less flying hours and flight cycles than they would in airline service, so they're likely in better shape than age suggests.
Wouldn't the service station still need to collect the federal gas tax? There would be two completely different systems at work, trying to accomplish essentially the same goal (collecting highway taxes). Government efficiency at its finest!
They don't generate heat as such, but AC->DC conversion does...
LEDs do generate heat as such, but less than an incandescent bulb. Low power LED indicators don't make much heat because they are low power (10-100mW), but high brightness LED arrays for room lighting usually require heat sinks to keep the junctions at a safe operating temperature.
The CFL ballast performs both an AC to DC conversion (at 50-60Hz) and a DC to AC inversion (at 20kHz or higher). The fluorescent tube uses AC, so the discharge current can be limited by an inductor. The higher AC frequency means the inductor can be very small compared to a line-frequency ballast with a big iron core.
There are some nice ICs designed for HF ballast applications, offering improved performance and protection functions. You won't find them in low cost CFLs. Every circuit shown on that page is a two transistor self-oscillating inverter. There is no output regulation, there is no power factor correction, some lack RFI filtering, some even omit the fuse or fusible resistor. If low cost LED lamps become available, expect them to also use the cheapest possible solution!
A 12V car charger will do nicely. Most phones come with one, and even if yours doesn't they're widely available and don't cost much. The charger is low current, so you don't need to run the engine while charging.
The bigger concern is the cell company's infrastructure. I can't believe they fought the FCC's run time and maintenance requirements. Because the cell phone system is part of the 9-1-1 communications infrastructure, I'd expect at a minimum NFPA 110 Class 24, level 2 compliance (24 hours run-time before refueling).
Batteries would have higher loss than that giant ceramic capacitor in regenerative braking systems. Even at very slow charge and discharge rates, the best you can expect from a battery is about 90% efficiency. At the high rates needed for braking and acceleration, it's considerably lower. Charge voltage is higher than the discharge voltage in a storage battery, and by more just than the IxR resistive losses. If you trace the terminal voltage vs. charge (Coulombs) for charge/discharge cycle, the path traces a hysteresis loop. The area enclosed by that loop is the energy loss.
On the other hand, a big drawback for this giant capacitor is the high operating voltage (3.5kV, per the patent). Power electronic systems for that voltage are expensive and difficult to build. The voltage drops considerably during discharge: getting 75% of the energy out of the cap means operating to half the peak voltage, and at twice the current required at full bus voltage. That, too, makes electronics more expensive for the same power output.
The 375V battery in the Tesla Roadster allows use of parts marketed for 240Vac line applications, which are sold in high volumes and therefore competitively priced. The question is whether the benefits of the capacitor (reduced size and weight) justify the more expensive electronics.
"*** Not measured -- arcing hazard too great at close separation." In this case, "close separation" means 4m away, so don't put this in your room. Forget about RF radiation, worry about the fire hazard!
No, C1 is a "type X" capacitor connected from line (L) to neutral (N), with only the input fuse between the cap and the power cord. C1 is a differential mode noise filter, and presents a badly mismatched termination to the BPL signals on the L-N wire pair.
Your reasoning does apply to C3 and C11, much smaller "type Y" caps connected from the rectifier output to ground (E, "Earth"). The combination of less capacitance, common mode chokes L2 and L3, and ferrite bead L1 means that C3 and C11 won't significantly influence signals sent over the power line.
There is a bleeder, but it's not obvious from the schematic. U1 draws some supply current through its "D" pin, and various other resistor strings (R3-R4 and R7-R8-R9) bleed off a bit more current. There's not a lot of bleed current by design: you have to keep it low to meet the Energy Star efficiency and stand-by power limits, and you need to meet them to sell products in California (among other places). The charge on C2 isn't available at the line cord, because the bridge rectifier blocks the reverse current flow. So a discharge time measured in minutes is fine for that part of the circuit.
What is important is to discharge C1, which is where R1-R2 come into play. Those are sized to waste as little power as possible, while still meeting the safety requirements for discharging C1 to a safe level quickly after disconnecting the AC line plug.
There are more issues that make RF communications on power lines very difficult. Growing numbers of devices plugged into the AC line generate RF noise, which must be controlled to meet FCC regulations (and overseas equivalents). Manufacturers of switch-mode power supplies include filtering to meet those requirements. That means there's a filter cap lurking inside, shorting out BPL signal on the power line (in this typical example, it's C1). Every time you plug in another device, the AC line transmission path is further compromised.
The state-of-the-art power supply designs also use "spread-spectrum" clocks, to distribute the noise over as much bandwidth as possible. That reduces the power at any one frequency to ease the RFI filter requirements, but does so by moving noise power to what would have been quiet spots between the noise peaks of a fixed-frequency clock. In other words, the BPL system can't choose a quiet operating frequency, because there are none. See figure 3 of the previous example. At frequencies above 2MHz, the individual clock harmonics blur together. The emissions are 10dB or more below the legal limit at the peaks, but aren't very much lower between them. This is frequency spreading at work.
Now imagine such devices being attached to every light fixture in the house (modern CFLs and LED lamps both use switch-mode technology). Getting a signal from the utility system to a household outlet will become increasingly difficult. BPL is not a good fit for the modern household.
If the device being interfered with has a "CE" mark, that means it's supposed to pass several IEC RF immunity tests. Recent changes have added higher frequencies to the test, to address the operating frequencies of newer cell phones etc. The performance levels for consumer-grade equipment aren't especially high, but are much better than nothing at all. 2W radiated from a cell phone should not exceed the test level (3V/m) at 3m distance from the antenna. So equipment in the next room should be OK, but anything within arm's reach of the phone user is in a much stronger field and likely to be interfered with.
...there's the reputation effect of guest authorship where having a well-known, senior, academic's name on the paper helps it through no matter how absurd the findings.
There's an antidote for that: blind reviews, where the authors' names and affiliations are removed from the review copies. Even the cited references can be removed, because authors are more inclined to cite papers from their own department than those of competitors. It's not a perfect solution; you can still see the authors' writing style, terminology, etc. and in many cases that's enough to identify the papers' origins. But it does help the reviewers to rate the papers more on their quality, and less on the reputation of the author and research lab that produced them.
Wasn't platform independence the selling point of UCSD's p-system? Yes, it worked, but it never really caught on. One camp of software development says that hardware is always getting faster, cheaper and more efficient, so adding a layer of abstraction between the source code and the hardware is not a problem. The other camp says we can use those same performance improvements to build software that does more things, on larger data sets, with better graphics, and in general make what once were impractically large and complex software tasks run on the average users' systems. Over the last three decades, the market has favored the latter.
The economy benefit comes from engine braking being s-l-o-w, so you learn to get off the throttle sooner. It doesn't matter if you turn kinetic energy into hot brake rotors via friction or hot air via compression, either way it's disposed of (OK, maybe 30% gone if you have a hybrid or EV with regenerative brakes). Using engine braking discourages you from charging up to the red light under power, then braking hard only when you must. Downshifts don't save fuel, you can get the same savings by braking early and very gently to stop in the same distance as you would with engine braking. They just teach you to plan ahead and make better use of the energy you expended accelerating up to speed.
Engine braking is the way to go for descents in the mountains, even with an automatic transmission (it has PRND L for a reason). Besides keeping the friction brakes cooler, not riding the pedal constantly makes the brake lights meaningful to the driver behind you. If the brake lights are always on, they are just as useless as if they don't work at all.
Yes there still are NiCd batteries on the market, but they aren't popular for applications where NiMH batteries meet the needs. NiMH usually gives more A-Hrs in the same package compared to NiCd, at a comparable price. But NiCd is better for high peak current, cold weather use, is more tolerant of overcharge, and less toxic when it's disposal time. They're still sold in the US, but the RoHS regulations have banned them in most products sold in Europe.
No, there's no open season on fleeing fugitives. You can't shoot them unless they're an immediate threat and you reasonably believe that anything less would be inadequate to stop that threat, or if they have illegally entered your house and you have reason to believe they intend to harm you or commit a crime. Colorado's self-defense laws don't allow you to shoot somebody who's running away. Ignore the hype, "Make my day!" vigilante action is illegal here.
It's like a usenet flame-war, or a telemarketer. If you continue to respond, it only encourages them to continue the exchange.
Give them one polite response, maybe two if you're feeling generous. After that, ignore their posts. Deny them the satisfaction of harassing you. If their posts continue or worsen, expel them from the forum. It's your site, and you set and enforce the acceptable use policy for your forum. If you don't have an AUP posted for your site (I can't tell; you just slashdotted your own site!) then the first step is obvious.
Second, NEC ampacity standards are for tolerable voltage drop, not wire overheating. A 200A-rated line will actually carry a lot more than 200A.
That is backwards! The NEC ampacity tables (310.16, 310.17, etc.) are concerned with conductor heating. That's why there are:
Separate columns for different wire temperature ratings
Reduction factors for higher than normal ambient temperatures
Different tables for single conductors and multiple conductors in a raceway or cable
Adjustment factors for more than three current-carrying conductors in the same raceway or cable
The only exceptions to the temperature-based ratings are for 15A, 20A, and 30A circuits. In most installations these must use at least 14AWG, 12AWG and 10AWG conductors (respectively), even if the Section 310 tables otherwise permit a smaller conductor.