This is the absolute perfect application for a water-cooled system. You just have to come up with a heat exchanger that dumps heat to the seawater outside, instead of the air. And it would be totally fanless, too!
It would probably be a bit more realistic to find a manufacturer of a box which is conductively cooled to the outer (sealed) casing. That takes care of corrosion issues in the computer itself; the keyboard, mouse and display will have to take care of themselves, and of course you're going to have to use something like a USB floppy/CD drive to avoid penetrations through the casing.
Must depend where you are; I checked with some local restauranteurs and they have to pay to have their waste grease taken away. Converting it to bio-fuel would at least set a ceiling on what it costs to dispose of it. On top of this, I've read that biodiesel (the methyl esters, not the raw vegetable oil) is a superb lubricity additive and can replace the sulfur compounds which currently lube the injection pumps (and create nasty particulates). Looks like we should be paying companies to use waste grease for fuel. We could easily pay for it by getting rid of the wasteful ethanol subsidies and mandates (as if Archer Daniels Midland would let that happen).
I haven't done the propagation checks, but I'll bet you dollars to doughnuts that the 5 GHz stuff has much worse attenuation than 2.45 GHz. For a dense urban area where interference and raising the noise floor is an issue, attenuation is good (it keeps users out of each other's hair); for a rural scheme where you are regularly linking over hops of several miles, it's very bad.
I think you missed the point
on
Microsoft Freon
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· Score: 2
CFCs were being produced world-wide for decades before the ozone layer became a political issue and the Montreal Protocol was implemented to deal with it. Even after that, CFCs were being smuggled into the USA because they are so much cheaper than HFCs. And no, most of them are not manufactured by DuPont and do not carry the Freon trademark. IIRC, China and Mexico are big producers; they were given more time, as "developing countries", to shift to non-depleting refrigerants. Of course, people there have exploited this for everything it's worth (their entrepreneurs are no less smart than our entrepreneurs).
If you think that the ozone-depletion problem is part of a conspiracy to jack up DuPont revenues, you need to check your tinfoil hat, it's leaking.
One REALLY big question... does the 131,000 BTU figure include the energy absorbed from the sun?
No; most of that winds up as heat (of course, much of it would wind up as heat pretty much regardless of what it landed on). Again IIRC, the figure only accounts for inputs in the form of:
Fuel for cultivation and spraying;
Fertilizer and pesticides; and
Processing and distillation of the product.
If we were just trying to get off imported oil for motor fuel, the way to go would be to use CNG, LNG or oxidize methane to methanol to make liquid motor fuel. There are a bunch of manufacturers making cars that run on M85.
Freon was patent-free for decades
on
Microsoft Freon
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· Score: 2
I hate to come along this late, but I found this comment in meta-mod and... According to this page on Freons, they were patented in 1928. This would have put them ex-patent in 1945.
Between fertilizer, pesticides/herbicides and fuel required for cultivation, a gallon of ethanol yielding 77,000 BTU of energy requires inputs totalling about 131,000 BTU (if memory serves). In other words, it's a complete boondoggle.
Diesel engines have greater NOx emissions than most gasoline vehicles, plus vastly higher particulate emissions. I understand that both of these can be dealt with but you won't be able to buy a vehicle with such technology installed. If you are motivated by a desire to keep the air clean rather than carbon-abatement you are probably better off with one of the gasoline or CNG vehicles instead. People living in thinly-populated areas with large distances to travel would probably make the opposite selection, on the merits.
I read your post just fine the first time, and I told you that it is inconsistent. To illustrate another place where you've made an error in your gedankenexperiment,
I said you have to make the ball pivot on the pole, so it *lags* 90 degrees out of phase with the Moon.
Okay, this arm is lagging 90 degrees behind the Moon. (Why not just extend the arm directly to the Moon and transfer force by contact?) To maintain its position 90 degrees behind, you will have to apply torque to brake it. This braking torque will be transferred to the Earth as accelerating torque. This process does not produce energy (contrary to your "generator" claim), it consumes it.
Also, "so the rest of the Moon moves outward and slows down," seems wrong. Speeding up the Moon would move its orbit outward.
There is no contradiction. Higher orbits move more slowly; in Newtonian mechanics, the orbital period is proportional to the 3/2 power of the semimajor axis. If you have an elliptical orbit the motion will be faster at periapsis than a body in a circular orbit at the same altitude, but the overall orbital period will still be greater.
You can work these things out for yourself using simple algebra. Just remember that angular momentum (m * R cross v) is a constant, and energy (1/2 m v^2 - m1m2g/r) is also constant. If only only consider conditions where v and R are perpendicular (circular orbit, or periapsis and apoapsis of an elliptical orbit) given the speed and radius at one point you can solve for the condition at the other; the only thing you have to solve is a slightly complex quadratic.
You could put a generator on the arm, and tap out the power, which would slow the Moon down in its orbit, and gradually lower it toward the Earth.
This is simply backwards. The Earth turns in the same direction that the moon orbits, but about 28 times faster. Generating drag between the Earth and the Moon (as tides do) results in the moon being *accelerated* and *lifted* in its orbit, while the Earth's rotation slows down.
You could accelerate the Earth if you wanted to, and generate electricity. This requires something like a 3- or 4-step process:
Lift lunar rock off using a long beanstalk extending toward Earth.
Drop material from the end of the beanstalk into an elliptical orbit falling in toward Earth, preferably an orbit with its perigee below Earth's geosynchronous orbit.
This time using a beanstalk coming up from Earth, catch this material with a device which converts its excess kinetic energy to electricity. The transfer of angular momentum also accelerates Earth's rotation.
If you've caught this stuff at or below geosync, you can just lower it down to Earth and convert the remaining potential energy to electricity (like a hydro turbine, only with moon rocks). This process transfers even more angular momentum to Earth.
What happens to the Moon in this? The process of sending material Earthward on the first beanstalk conserves angular momentum, so the rest of the Moon moves outward and slows down, making the month longer.
How does that contradict the poster's point about *American* cars?
Okay, I'll lay it out more plainly for you:
The "efficient" European manufacturers are among the worst offenders in the guzzler category over here.
This makes it obvious that the manufacturers are driven by some common concern.
(speculation which was left as an exercise for the reader in grandparent post) This may well be that imports tend to be luxury items and the people who buy them don't care much about efficiency, but subordinate it to status and comfort.
If you had the time and data to be able to see what a more-efficient US-market car would sell for if it was sent to Europe and how profitable it would be, you could check this out. I suspect (speculation) that such cars could not be sold profitably, which is why the only ones seen in Europe tend to be the (luxurious, status-promoting) guzzlers.
Your theory that the US's size causes the increased energy consumption is interesting and probably half-true... but we have a much, much lower population density (6 ppl per sqm compared with 77 ppl per sqmile in the US) here in Australia, yet our per capita energy use is still only 2/3 that of the US...and we are a first tier industrialised developed nation.
As I recall, the great majority of your population lives in a few mega-urban zones, and the rest of the continent is almost empty. If most of your energy is used for transport and you've achieved the density required to make buses and trains work well, you're in the same situation as Europe.
Well, it can add to the torque of the engine actually, on heavy thrust demands.
I was going to mention that if you hadn't. What you did miss is that energy-management can use the starter-generator as a dynamic brake and store energy in the vehicle battery.
On manual gearboxes, it restarts the engine when the clutch pedal is pressed. Automatic gearboxes?
Some automatics have had a feature called "neutral idle" which un-clutches the transmission when the vehicle is not moving and the driver's foot is on the brake. This eliminates the drag of the torque converter and reduces idle fuel consumption. It would be just as easy to shut down the engine entirely.
In Europe, and probably elsewhere, American cars have a reputation for being gas-guzzlers. Live with it.
If you have lived in the US for any length of time, you will also realize that the European imports to the US are some of the worst offenders in the gas-guzzling category. V8 Mercedes and V12 BMW's are particularly bad examples. In other words, you are being attacked for putting forth an argument which doesn't stand up well under examination.
I've been talking up the need for increased fuel taxes as a way to discourage consumption for over a decade. You can see how much progress I've made.
Gibraltar, which is part of the European continent (the Iberian peninsula, to be precise) and is a part of the British Empire for at least a little while longer.;)
It is also indisputable that America is ENORMOUSLY larger and less densly populated than any country in Europe, leading to vastly greater distances to be crossed to accomplish normal business and making the European's favorite solutions of trains and buses utterly impractical for getting around.
On top of this, America accounts for a huge amount of the world's industrial production. A great deal of that energy is actually being used for something. While I will not argue that the USA couldn't do quite a bit to increase efficiency in all parts of the economy (just about everything I've tried to check in depth makes it appear that 2x is quite realistic for most applications not involving direct conversion of electricity to heat), there are excellent reasons why the USA is always going to have higher energy consumption per-capita than the "good folks" of Europe even if they are employing the same technologies just as well.
You have engaged in the non-formal inductive fallacy of semantic confusion. Whereas, I was using the more colloquial definition of 'efficiency'' i.e. mpg, you used a more technical thermodynamic definition of 'efficiency'' i.e. nu (the greek letter).
In other words, I was correcting your fallacious argument (implied by your false equivalence between different motor fuels) by using a more precise definition. I plead nolo contendere.
Can all these changes be implemented by the auto manufacturers?
It's not necessary to make a production vehicle exactly like the experimental one, it's only necessary to achieve the same results. The Moolennium (click on the Moolennium link on the right) got 32 MPG. Heck, Ford itself was talking about a 40-MPG Escape for production in what, MY2004?
These trucks must be inexpensive enough to produce to be inexpensive enough for the average consumer.
No they don't. The price of the truck needs to incorporate all the external costs which are currently foisted off on the rest of the world. If fuel cost $5/gallon it would make efficient trucks quite attractive even without much prompting, and $5/gallon is probably what petroleum fuel would cost if all of the external costs of protecting the Persian gulf, subsidizing Saddam Hussein and the Wahhabi fundamentalists of Saudi Arabia (the folks whose theology drives Usama bin Laden and Al Qaeda) and other things were charged at the pump.
And aluminum as safe as an all-steel frame?
Pound for pound, aluminum is much stiffer and stronger than steel. That's why modern aircraft are built mostly out of aluminum (where they haven't gone to composites).
You are right about air quality, but I think that if we aren't willing to shoot for a doubling of fuel economy in our vehicles (and quite a bit more in the rest of the economy via co-generation), frankly we are being lazy pikers. We can double economy with technologies which are student playthings; when you consider the kind of advances which are currently in the real labs, and how they could come to the car dealerships and merchandise racks at Home Depot and Lowe's over the next 20 years, you have to wonder what excuse there is for doing nothing. I sure don't see one.
Diesel has a greater density than gasoline, and thus that is why Diesel engines are more efficient than gasoline engines.
Um, no. If all you did was substitute a fuel with more energy/gallon (such as gasoline for propane), you will get more miles per gallon even at the same efficiency. Greater energy density of the fuel does not make an engine more efficient. You might also want to look at this paper, where it states:
Burning natural gas and propane gives less carbon dioxide and more water vapour per energy unit than burning gasoline or diesel fuel. Carbon dioxide is the most important
greenhouse gas. International agreements to reduce carbon dioxide have been signed/39/.
The emission of greenhouse gases is dependent on both the efficiency of the whole chain
and fuel chemistry. Evaluations of energy consumption and greenhouse gases should be
carried out over the whole fuel chain including production, distribution and utilisation (life
cycle analysis, LCA).
One argument heard in promoting natural gas as an automotive fuel is that natural gas
reduces carbon dioxide emissions compared to conventional hydrocarbon fuels. This is
most cases true when substituting gasoline with natural gas.
The situation is different for heavy-duty vehicles. The thermal efficiency of the Otto cycle
is lower than that of the diesel cycle, and therefore the energy consumption of a heavyduty
spark-ignited natural gas or propane engine is higher compared to the diesel engine.
The fact is that diesel engines running on typical fuels use higher compression ratios than Otto-cycle engines, and higher compression means greater efficiency. The diesel also runs without a throttle, eliminating throttling losses at partial power and further increasing efficiency; engine torque is modulated by reducing the fuel without changing the airflow, which cannot be done in an Otto-cycle engine because the engine will misfire when the mixture gets too lean.
If you run an Otto-cycle engine exclusively on propane rather than gasoline, and increase the compression to suit the fuel, you will get higher efficiency and lower CO2 emissions than the gasoline version... but at 5 pounds of propane per gallon vs. 6.2 pounds/gallon of gasoline, you are still going to get fewer miles per gallon.
(I know you were trolling, but there are some valid points to be made in response.)
The balloons themselves are made of latex, a natural substance derived from plants. They decay in ultraviolet light and break down quite naturally. An airplane hitting one of the balloons probably wouldn't notice. An airplane hitting one of the payloads might suffer some damage, but the construction of those radiosondes is for lightness, not durability. How much punishment do you need to take, riding up into the sky under a balloon?
Of course, all the balloons come down by themselves within a rather short time. Sheer UV and ozone embrittlement of the balloon envelope will do it if nothing else does. They burst and come down in rather small pieces (if you want to see what happens you can buy a balloon from one of the scientific surplus houses which sell them, and inflate it with your shop vac until it explodes).
What gets me is the claim that the payloads are unrecoverable. How hard could it be to equip each one with a mylar Rogallo kite and have it aim toward its ground station once the balloon bursts and lets it start gliding down? A 5:1 lift/drag ratio means a range of about 100 miles starting from 100,000 feet. What do you need to guide it, one model-airplane servo? This isn't rocket science.
Wrong battery type, missing information
on
24/7 Notebook Power?
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· Score: 5, Informative
A motorcycle starting battery is almost certainly not suitable for this job. Starting batteries are meant to power a starter motor for a few seconds, discharging them a few percent. Then they are recharged almost immediately. Using them otherwise is a sure bet for rapid capacity loss and early failure.
This application is totally different. The laptop and battery would be in use for at least the duration of a shift, possibly all day. This calls for a deep-cycle battery which can be drained to a large fraction of its capacity on every cycle without taking damage. Something in the form factor of a motorcycle battery might do the trick, but you wouldn't want the real thing.
The article is missing information on the actual power drain of the laptops and the required period of operation before recharges. If we can assume that the laptop draws 30 watts and it needs to run for a 10-hour shift, that's 300 watt-hours. If you could get a 50 amp-hour deep-cycle battery, it would only go to 60% depth of discharge on that cycle. Such a battery would probably weigh about 30-35 pounds; an absorbed glass mat design has no free liquid electrolyte and would probably meet the hospital's safety requirements. If you need more capacity or less weight you are probably talking NiMH batteries and your cost/WH goes way up.
Another thing that's missing is whether the batteries must be mounted to the equipment (is there a risk of them being stolen?) or if they can be made swappable. It would be much easier to have a battery in a little carrier that slips into the cart and plugs in than to have it mounted to the cart; being able to hot-swap batteries would make it very easy to have a set in use and another set charging at all times. This is a lot better than having to park the cart and plug it in for the duration of the charging cycle when the nurse needs to be on the floor.
Finally, you're going to have some issues with regard to tracking of the battery cycling and lifespan. A solution to that involving something like Dallas Semi iButtons could easily cost ten times as much to engineer and roll out as all the batteries in your hospital. If you do it on paper or by ear, you're going to be caught by surprise by flaky units or systematic problems with over-discharged batteries (which can hammer you with costs at very inconvenient times). Tracking batteries, their charging and discharging behavior and other vital stats with paper is just too error-prone and labor-intensive to work well. This guy's going to need all his smarts to make this work, no doubt about it.
An off the shelf 12v inverter and a marine battery could last quite a while, but you'd still have to charge it eventually.
He already said that the nurses couldn't push something the weight of a car battery, which marine batteries are. I'm a big guy and I can push (or curl) a deep-cycle battery with no problem. You want to assign some little Filipina nurse to shove it around all day along with the rest of her gear?
On top of that, the laptop is already set up to accept DC input. Carrying an inverter on the cart to run the AC power supply just adds two redundant conversion steps and their losses, plus the capital cost of the inverter and its wiring plus the downtime from the inevitable failures. You must have some critical thinking skills somewhere; try using them.
Having a bank of spare batteries charging off of a solar array would also be an interesting alternative.
The author said:
Unfortunately, charging and replacing lithium-ion batteries is expensive, and cost is definitely an issue.
Slashdot Mirror
It would probably be a bit more realistic to find a manufacturer of a box which is conductively cooled to the outer (sealed) casing. That takes care of corrosion issues in the computer itself; the keyboard, mouse and display will have to take care of themselves, and of course you're going to have to use something like a USB floppy/CD drive to avoid penetrations through the casing.
... you've never heard of laptops (which run LCDs off of 12 volts, more often than not) or inverters.
I haven't done the propagation checks, but I'll bet you dollars to doughnuts that the 5 GHz stuff has much worse attenuation than 2.45 GHz. For a dense urban area where interference and raising the noise floor is an issue, attenuation is good (it keeps users out of each other's hair); for a rural scheme where you are regularly linking over hops of several miles, it's very bad.
If you think that the ozone-depletion problem is part of a conspiracy to jack up DuPont revenues, you need to check your tinfoil hat, it's leaking.
- Fuel for cultivation and spraying;
- Fertilizer and pesticides; and
- Processing and distillation of the product.
If we were just trying to get off imported oil for motor fuel, the way to go would be to use CNG, LNG or oxidize methane to methanol to make liquid motor fuel. There are a bunch of manufacturers making cars that run on M85.I hate to come along this late, but I found this comment in meta-mod and... According to this page on Freons, they were patented in 1928. This would have put them ex-patent in 1945.
Between fertilizer, pesticides/herbicides and fuel required for cultivation, a gallon of ethanol yielding 77,000 BTU of energy requires inputs totalling about 131,000 BTU (if memory serves). In other words, it's a complete boondoggle.
Unleaded burns cleaner, but the diesel will usually have lower carbon emissions. As always, YMMV (pun intended).
Diesel engines have greater NOx emissions than most gasoline vehicles, plus vastly higher particulate emissions. I understand that both of these can be dealt with but you won't be able to buy a vehicle with such technology installed. If you are motivated by a desire to keep the air clean rather than carbon-abatement you are probably better off with one of the gasoline or CNG vehicles instead. People living in thinly-populated areas with large distances to travel would probably make the opposite selection, on the merits.
You can work these things out for yourself using simple algebra. Just remember that angular momentum (m * R cross v) is a constant, and energy (1/2 m v^2 - m1m2g/r) is also constant. If only only consider conditions where v and R are perpendicular (circular orbit, or periapsis and apoapsis of an elliptical orbit) given the speed and radius at one point you can solve for the condition at the other; the only thing you have to solve is a slightly complex quadratic.
Fruit flies are attracted to vinegar, and if you want them out of your kitchen....
You could accelerate the Earth if you wanted to, and generate electricity. This requires something like a 3- or 4-step process:
- Lift lunar rock off using a long beanstalk extending toward Earth.
- Drop material from the end of the beanstalk into an elliptical orbit falling in toward Earth, preferably an orbit with its perigee below Earth's geosynchronous orbit.
- This time using a beanstalk coming up from Earth, catch this material with a device which converts its excess kinetic energy to electricity. The transfer of angular momentum also accelerates Earth's rotation.
- If you've caught this stuff at or below geosync, you can just lower it down to Earth and convert the remaining potential energy to electricity (like a hydro turbine, only with moon rocks). This process transfers even more angular momentum to Earth.
What happens to the Moon in this? The process of sending material Earthward on the first beanstalk conserves angular momentum, so the rest of the Moon moves outward and slows down, making the month longer.- The "efficient" European manufacturers are among the worst offenders in the guzzler category over here.
- This makes it obvious that the manufacturers are driven by some common concern.
- (speculation which was left as an exercise for the reader in grandparent post) This may well be that imports tend to be luxury items and the people who buy them don't care much about efficiency, but subordinate it to status and comfort.
If you had the time and data to be able to see what a more-efficient US-market car would sell for if it was sent to Europe and how profitable it would be, you could check this out. I suspect (speculation) that such cars could not be sold profitably, which is why the only ones seen in Europe tend to be the (luxurious, status-promoting) guzzlers.I've been talking up the need for increased fuel taxes as a way to discourage consumption for over a decade. You can see how much progress I've made.
Gibraltar, which is part of the European continent (the Iberian peninsula, to be precise) and is a part of the British Empire for at least a little while longer. ;)
On top of this, America accounts for a huge amount of the world's industrial production. A great deal of that energy is actually being used for something. While I will not argue that the USA couldn't do quite a bit to increase efficiency in all parts of the economy (just about everything I've tried to check in depth makes it appear that 2x is quite realistic for most applications not involving direct conversion of electricity to heat), there are excellent reasons why the USA is always going to have higher energy consumption per-capita than the "good folks" of Europe even if they are employing the same technologies just as well.
You are right about air quality, but I think that if we aren't willing to shoot for a doubling of fuel economy in our vehicles (and quite a bit more in the rest of the economy via co-generation), frankly we are being lazy pikers. We can double economy with technologies which are student playthings; when you consider the kind of advances which are currently in the real labs, and how they could come to the car dealerships and merchandise racks at Home Depot and Lowe's over the next 20 years, you have to wonder what excuse there is for doing nothing. I sure don't see one.
If you run an Otto-cycle engine exclusively on propane rather than gasoline, and increase the compression to suit the fuel, you will get higher efficiency and lower CO2 emissions than the gasoline version... but at 5 pounds of propane per gallon vs. 6.2 pounds/gallon of gasoline, you are still going to get fewer miles per gallon.
The balloons themselves are made of latex, a natural substance derived from plants. They decay in ultraviolet light and break down quite naturally. An airplane hitting one of the balloons probably wouldn't notice. An airplane hitting one of the payloads might suffer some damage, but the construction of those radiosondes is for lightness, not durability. How much punishment do you need to take, riding up into the sky under a balloon?
Of course, all the balloons come down by themselves within a rather short time. Sheer UV and ozone embrittlement of the balloon envelope will do it if nothing else does. They burst and come down in rather small pieces (if you want to see what happens you can buy a balloon from one of the scientific surplus houses which sell them, and inflate it with your shop vac until it explodes).
What gets me is the claim that the payloads are unrecoverable. How hard could it be to equip each one with a mylar Rogallo kite and have it aim toward its ground station once the balloon bursts and lets it start gliding down? A 5:1 lift/drag ratio means a range of about 100 miles starting from 100,000 feet. What do you need to guide it, one model-airplane servo? This isn't rocket science.
This application is totally different. The laptop and battery would be in use for at least the duration of a shift, possibly all day. This calls for a deep-cycle battery which can be drained to a large fraction of its capacity on every cycle without taking damage. Something in the form factor of a motorcycle battery might do the trick, but you wouldn't want the real thing.
The article is missing information on the actual power drain of the laptops and the required period of operation before recharges. If we can assume that the laptop draws 30 watts and it needs to run for a 10-hour shift, that's 300 watt-hours. If you could get a 50 amp-hour deep-cycle battery, it would only go to 60% depth of discharge on that cycle. Such a battery would probably weigh about 30-35 pounds; an absorbed glass mat design has no free liquid electrolyte and would probably meet the hospital's safety requirements. If you need more capacity or less weight you are probably talking NiMH batteries and your cost/WH goes way up.
Another thing that's missing is whether the batteries must be mounted to the equipment (is there a risk of them being stolen?) or if they can be made swappable. It would be much easier to have a battery in a little carrier that slips into the cart and plugs in than to have it mounted to the cart; being able to hot-swap batteries would make it very easy to have a set in use and another set charging at all times. This is a lot better than having to park the cart and plug it in for the duration of the charging cycle when the nurse needs to be on the floor.
Finally, you're going to have some issues with regard to tracking of the battery cycling and lifespan. A solution to that involving something like Dallas Semi iButtons could easily cost ten times as much to engineer and roll out as all the batteries in your hospital. If you do it on paper or by ear, you're going to be caught by surprise by flaky units or systematic problems with over-discharged batteries (which can hammer you with costs at very inconvenient times). Tracking batteries, their charging and discharging behavior and other vital stats with paper is just too error-prone and labor-intensive to work well. This guy's going to need all his smarts to make this work, no doubt about it.
On top of that, the laptop is already set up to accept DC input. Carrying an inverter on the cart to run the AC power supply just adds two redundant conversion steps and their losses, plus the capital cost of the inverter and its wiring plus the downtime from the inevitable failures. You must have some critical thinking skills somewhere; try using them.
The author said: Your reading skills need a tune-up also.