By the way, the reason I mentioned penicillin had to do with the fact that Fleming originally discovered the microbe in the late '20s, but it wasn't until early in WW2 that technology came into being that allowed the mass production of the drug.
The relevance (which my underslept brain wasn't providing the other day) is that it seems like this new technique might have the same type of multiplicative effect on stem cell research that corn steep liquor had on penicilllin)
Keeping in mind that my answer is drawing from a micriobiology class I took in the dim dark ages (the late '80s), two years is a helluva long time because we're not talking about the age of the organism, we're talking about the number of generations of cells from the original that seem to be multiplying without observed mutation, etc.
In fact, we studied a particularly remarkable cancerous cell line that was significant in that even though the patient died something like twenty five years ago (?), the particular cell line has remained viable (it still divides into new cells true to the original) since then.
I haven't decided how related this is, but penicillin only became a useful antibiotic only after a couple of other inventors were able to find a growth medium (corn steep liquor) that allowed large quantities of the organism to breed true.
So if the New Scientist article is correct and there is not a generational OR a quantity limiting factor in these cells, my thought is that this is a Noble-Prize level discovery.
With a question... Given the current lawsuits against 2600, etc., if Microsoft comes up with their own streaming video format, and someone programs for interoperability [the same way that deCSS decodes but does not copy CSS-encoded DVDs], what's to stop M$ from using the DCMA to punish/prohibit any non-windows OS programmers up to and including the WINE team.
Or from extending the same logic and copyrighting the file formats for MS office files, and that any attempts to sell software that decodes them outside of M$ operating systems are a violation of the DCMA, etc.?
Oh.... this could be good. See if my logic holds water or not...:
The RIAA tries to clobber Phillips with the DCMA,
Phillips replies in effect saying "okay fine. Since your CD's don't comply to the CD-DA standard which we licensed to you in our patents, you are in violation of the licensing agreements which allowed you to use our patented technologies."
Phillips sues the RIAA for breach of contract and obtains an injunction blocking future sales of all or just the incompatible CDs.
RIAA companies can no longer sell a certain amount of music until the court case is finished.
The RIAA folds on copy protection because they can't afford to lose that much money in sales.
Myself, I'd bet against any such thing happening, because Phillips would lose alot of money as well, but wouldn't it be nice if I was wrong?
Since so far virtually no 32 bit OS from Microsoft has proven to be secure, why would we expect their latest greatest offerings to be any better? After all, this is the company that seems to be more focused on spending time and money to prevent interoperability (AKA Samba, the ever changing.doc file formats, the attempt to poison Java, etc., anti-competitor FUD) than they do on making sure their products are secure in the first place. Maybe they don't believe that they can be harmed by people who want to cause their OS to interoperate remotely in *cough* *cough* original and new ways not favorable to the users of the WinXX machine's interests, a.k.a. at the behest of computer virus writers.
Until their damn EULA gets blown away in court and they get sued and lose bigtime for negligence in how they handle security concerns, I don't see any reason why M$ would change things -- doing things right might cut into profitibility more than the aforementioned business methods we all know and love...to hate.
[Admitting right off tht this is probably a rant in disguise. And that most of my points are from memory and may not be 100% accurate -- feel free to correct at will and I thank you in advance]
Before the investment bubble burst last year, an unbelievable amount of fiber optic telco cable was laid, and IIRC, a lot of these lines have not even been activated, and won't be. Company after company has gone bankrupt trying to provide broadband and make money, even though most of us want the service.
Trouble is the damn RBOCs have managed to not only keep their local service monopolies pretty much intact but to strangle the up-and-comers at the connection point --- which was supposed to have been opened up by the 1996 telecommunications reform bill. Some legislators at the time grumbled that they had been sold a lie by the big telcos about the reforms, and promised to revisit the issue in the very next Congress... So here we are five years later... these same politicians continue to feed on the lobbyist cash cow, the RBOCS continue to rake in the profits on their existing poor service, and we wonder why nothing changes?
While some of Mr. Lessig's points strike true, in my view more of the problem has to do with big money corrupting the U.S. political process than any stranglehold on content because many of us would provide the content if we could get fairly priced access through-out the whole telco system.
Given how easily the ACLU gets up in arms about very small issues related to things like the 10 commandments on plaques, buildings, etc., why do you think that we aren't reading about the ACLU attacking bad legislation or proposed legislation(s) such as the DCMA, UCITA, the SSSCA (?), etc. ?
There is a very *bad* result of trying to take too much heat out of some smokestacks which hasn't been mentioned so far: condensation of heavier hyrdrocarbon molecules inside the smokestake... which can then catch fire and/or explode.
Actually, very few IC car engines even get 30% thermal efficiency, so as a previous poster noted the ability to grab even small amounts of waste heat for conversion into electricity could offer a substantial improvement in the basic power versus economy curves.
Texts I have read put the cooling waste for an IC engine at about 30%, which means that if the MIT devices could convert half of the heat wasted through the cooling system (not to mention the exhaust stream) to useful power, you would get a roughly sixty percent increase in fuel economy. Couple that with a hybrid system for autos or a diesel and now I'd even be interested.
By the way: top turbines now get around 40% thermal efficiency ratings , with combined cycle systems closing in on 60%. Big marine and stationary diesels can get close to 50%, but all of these are for huge engines/engine systems.
Too bad they haven't figured out how to downsize to much more moderate sizes without sacrificing the higher efficiencies offered by the big boys.
I thought so to. Until I realized that when you consider the efficiecy of the PV cells, it takes a great big set of wings to generate even the equivalent of 10 horsepower/hr. During the day. During the summer. (unless you can afford the best ones -- which are worth well more than their weight in gold...)
By the time a non -charged piston engine is up to about 8000 feet, it's lost about 20%-30% of its original sea level power, IIRC, so about the best use I've come up with for PV cell power so far would probably be for turbo and or light supercharging so that the damn fuel hogging engine up front gets more O2 to burn as the aircraft goes higher. Since drag goes down as the plane goes up, this would be a good thing in terms of fuel economizing. Still leaving more than enough extra extra engine power for the instruments, I think.
Several notes from an aircraft engine enthusiast in response to your points....
In terms of weight and bulk, there are existing studies for aircraft designs that use fuel cells as the nighttime power source for high altitude unmanned missions during the night, with the hydrogen being provided from surplace PV electricity generated during daylight hours. Interestingly enough, PV efficiency was less critical to aircraft size and mission profiles than fuel cell weight, as you noted.
The article mentions that fuel cells are twice as efficient as heat engines.
Well, sort of. From what I have read, the top fuel cells are between 60% and 70% efficient when used in with a bottoming cycle to use the excess heat produced by the cell. Top (big) diesel engines are between 40% and 50%, turbines (jet fuel is similar to diesel and kerosene) can be anywhere from horrible up to nearly 60% (bigger newer = better efficiency). I have yet to read the specs for a gasoline fired production engine getting much more than 30%-35%, so a higher capacity fuel cell does pretty darn good compared.
The critical thing to consider in terms of weight is that (depending on mission profile), if the engine is twice as efficient, you can carry half as much fuel. So even if the engine system weighs 60 pounds more (which would be make most general aviation engine designers shudder) for most general purpose aviation engines up to around 300-400 hp, for any flights requiring more than about 10 gallons of fuel, the overall aircraft weight would go down.
As far as propellers, designs are pretty much optimizable already because the aerodynamic shape isn't generally affected by the engine pulses. What is being lost between pulses is a slight amount of rotational speed in the blade, so an electrical prop wth the exact same aerodynamic design should have a very slight performance advantage over a piston driven prop... provided that the electrical system doesn't add so much weight that the drag induced by the added weight doesn't actually increase the power requirements for the aircraft. Props are actually pretty good at turning shaft energy into thrust, btw, with a good prop providing about 85-90% of the shaft horsepower as thrust.
Just my 2 cents worth. If I am wrong about any facts or figures, jump in and let me know...:-)
dang fingers. Accidentally hit the enter key with the focus on the submit button instead of the double quote before I got the HTML fixed. Sorry folks.:-(
The only phrase that was supposed to be bold was "which is only true for extremely large diesel engines." The rest was supposed to be just plain text.
A little knowledge is a dangerous thing....and a lot of knowledge will get you a career.
As in I didn't say that my knowledge of thermodynamics was limited to one class. Which it isn't, by a factor of several years]. I only mentioned the first class because the knowledge is that elementary.
Out of curiousity, I looked at the VisionEngineer page, but it neglects to put the Gibbs energy, etc. into the overall exergy system -- which forces even a fuel cell to conform to known mathematical formulas and systems, none of which I want to type out and explain here.
You also accused my figures about IC engines to be drivel, because your source page shows that the state of the art for IC engines is somewhere above 52%.which is only true for extremely large diesel engines. If you take diesel engines out of the mix, the efficiency drops rather dramatically, and as far as I know there are no production automobile engines getting much more than 30%. The best non-turbine aero engines peak at around 37-38%. (By the way, I am humble enough to be willing to accept correction and update my knowledge base, if someone out there has figures showing something better)
Rather than resorting to the math, let me point out that one of the main by-products of a fuel cell is heat -- and in the case of the more highly efficient fuel cells, alot of it. In fact, so much heat that you can use the heat in a combined Air bottoming or Rankine Cycle engine system. That particular combination can theoretically get to about 75% thermal efficiency, but I haven't seen much that convinces me conclusively that it will go much higher.
So no matter what may be claimed, Fuel Cells are not 100% efficient and never will be. But we do agree that they have great potential to be a damn sight better than our current energy wasting IC engines.
Yes, the programmer had to translate the text into phonemes, but you know what? That wasn't the hard part, because with a decent translation dictionary, you can get about 95% of the words right with a simple one pass "phoneme compiler" and a good set of rules. The hard part is that English is a highly inflected language without a constant set of rules for doing the inflections.
Still, I was part of the team that made the first Apple II (at least in the State I lived in at the time) that could read from the screen back in 1981 -- to an "Echo II Speech Synthesizer" which IIRC came from Radio Shack.
We took some of our stuff to the linguistics department at the University across town, and of all things, had the darn machine speaking understandable Japanese (from Romaji, or romanized letters) within a few days because the Japanese language is consistent not only in phonetic translation but also in inflection. It still sounded like a machine, but that was a limitation of the sound chip's internal phoneme library in the Echo II. The same program with one of today's chips would have sounded very near normal.
Goes to show you how much more difficult spoken English is than most of us native speakers tend to realize, because I have yet to see a low cost implementation of a text to speech translator that was all that much better than what we were doing back in '81. (not that I have seen everything out there by the way -- I do have a life outside the PC world....occasionally:-)
Sorry to burst your bubble, but fuel cells do have the same limitations -- known as Carnot efficiency, btw. And the top temperatures and bottom temps are measured in terms of absolute zero, and metallurgical limits on the high end are currently around 1300K IIRC. So the best a person can get from any engine using existing metals is around (1-290K/1300k=) 77%.
It just so happens that the Carnot efficiency for the best current fuel cells is about double (50-60%) that of an internal combustion engine -- which is typically 25%-30%, not 30%-40% when you consider all losses. About the same as the best combined cycle (gas turbine + steam turbine) plants with a huge difference: fuel cells are small, where the best CC plants have always been in the 250 MW range or higher.
My source for info? a good introductory thermodynamics class.
I respectfully disagree, because until equality of human rights is guaranteed, there is no level playing field.
Your point seems to be that "so long as a nation is willing to allow their citizens to be exploited, there will be healthy competition" -- instead of the idea being "so long as there is healthy competition, the playing field can be leveled". The fact is, governments can either work for or against healthy competition, capitalism can either work for or against healthy competition, and even "big business" can work for or against healthy competition. Gee, a theme here... leading to the further question of "what is healthy competition?"
My definition: healthy competition raises the level of all those participating in the competitive process -- which is where most big businesses and gov'ts fail. [Notice that I deliberately left out 'capitalists', because they are usually allied with one of the two other groups -- and it is often the capitalists who find ways of leveling the playing field -- by investing in the newer competitors to the established concerns.]
Then we come to the idea that taxes are something stolen from a citizen to help a business. Face it, in the 21st century, taxes are what we use to pay for services we all want, but usually with less efficiency and much more corruption than the private market would deliver. However -- no private company seems eager to provide an equality of services to all comers like fair governments are ostensibly supposed to do.
The system falls apart when instead of the common good, governments, capitalists, and big businesses only look to further their own interests, regardless of the damage done to those outside their respective domains. In other words, by participating in unhealthy competition in which one set of participants must lose (and lose regularly) in order for the other side to gain.
Thus my contention is that it isn't free trade that will "save the world", but equitable trade -- for example, that allows a well run farm in Iowa to get a fair price for his products without requiring that a well run farm in France go out of business. With true globalism -- both farms must improve to compete -- so the issue isn't trade -- but unfair trade -- which is where we come back into agreement.
IMO most multinational companies aren't interests in free trade-- they are interested in gaining unfair advantage for their own constituent interests. Usually making their alliance with government interests suspect at best and undeniably evil at worst.
I'd love to look at their stuff, but it has been years since I "spoke" Fortran fluently, having moved most of my old stuff to C or C++. Are there any converters out there that are up to snuff for this kind of work?
Let me start by saying I would love to have some sort of rating system that worked web wide.
What I am not sure of is that I want the biggest companies acting as pitch men on the issue, because I for one do not trust the big companies to play fair one bit. Does anyone really think that the MPAA and the RIAA are interested in selling quality entertainment, as opposed to controlling the playing field? Remember, two of the largest corporate interests behind both the MPAA and the RIAA are AOL Time Warner and Disney... So why should I trust them to play fair with the administration or even development of a rating system, if they do not control my content directly?
My other issues are whether or not the blacklist is open for public review and change, and finally whether a website can offer more than one type of content under a given domain name. Which is why up to this point I oppose most sorts of filtering software is the lock-in -- I have to buy into using a proprietary, non-open list maintained by a corporate interest.
Secondarily, the so-called "white list" versions of blocking software have a similar problem -- someone has to rate the site to get on the list -- with all of the issues of list distribution or centralization, etc.
You know what works best for me? and doesn't require any new software or black/white list to work? Searching via Google with their 'safe" filters on, because 99% of the porn sites out there cross refer, and so when a new domain name gets a lot of hits from the known porn referrers, Google's algorithm correctly identifies the new site as, you guessed it -- another porn site. Easy, huh? Now all I have to do is get Google's attention for my own site....
Keeping /. alive: several thoughts
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Hopefully by the time I post this, at least part of it won't be too redundant, but here goes anyway:
Hopefully being a subscriber would have some little perks, but I would be glad to subscribe to/. anyway, because I ignore probably 95% of the banner ads which I see, which means that 95% of the page views I am getting aren't making money for CmdrTaco and crew who have put together a hellofa good site.
I would also be happy to fill out some kind of preferences survey so that the folks selling the click throughs at OSDN can get more $ per. For example, if my preferences show that I always ignore X banners, but often click on Y banners, I make $$/yr, etc., then an advertiser whose banner I do see and click through has already got a higher likelihood of a buy, so they should pay more for the click.
If the banners are served by a different machine than the text, a second cookie could store some of these prefs so that all of the OSDN sites I visit should get the same higher value for the click, right?
I would also love to subscribe to a/. magazine, but frankly haven't figured out how the crew could get something like this started without a huge investment in folks to market the ad space, or without taking on additional liability (i.e. editorial staff and legal staff) because a mistake or unidentified plagarism in the print game can hurt you in the pocketbook a whole lot more than just by pulling or changing a link or text online.
The last thing is something the/. crew might be able to do now, or maybe is even part of the current system: a comment mode where only comments rated at a certain level or higher, or which have been modded up at least once display full text, with unmodded responses displaying only the title. Seems like it would reduce the amount of text to be sent out without diminishing the quality or requiring more page views for folks browsing at 0 or higher.
By the way, a tool I have found useful in my online studies and research (but so far available only for WinXX machines AFAICT) is the Copernic 2001 search aggregator.
It's a cool tool because not only does it get and prioritize links from a bunch of the top search engines, it also has a mode that will go through the list that it returns and get rid of any dead links.
I'd be interested in anybody's experiences with similar software, btw.
You mean, PC's aren't everything? *grin* Actually, I am also part of that group who is finding out that there's a whole lot more interesting stuff out there than our little niche world of PCs, operating systems, etc. And my favorite textbook right now is...
The web. Seriously. I have learned more about more science in more subjects in two or three years by researching online than I have ever been able to get out of a textbook. I have also found mentors in various knowledge areas, on-line tutorials and tools that are also far superior to the textbooks. The end result is that I am taking a couple of textbook based classes, namely Calculus and Thermodynamics, (because they relate to my specific interests.
So my best suggestion is for you to figure our what you'd really really like to know more about, and then jump out there on the web and start learning, and when you discover a specific knowledge base (like Calculus) for which there is a good textbook available, go ahead and get it.
Nah, the Chiefs are way to unpredictable. Better to invest in things like airlines, then blow something up with an airline, and sell short...Oh wait, they haven't proven that yet.
The analysis below is predicated upon the reasonable conclusions that a) because Bert is more likely to be a closet Steelers fan (note the "steely" grimace...), and b) the Chiefs or Redskins could be conceivably be mistranslated into Arabic to represnt an oppressed people whose homeland has been confiscated by the evil invaders.
Our conclusion, developed using all of the available CIA supercomputers, is that the above over/under betting plot is designed to undermine the free world, that anyone who makes this bet in an off shore Internet casino is a terrorist, because that is the only bet that Osama can reasonably make because either he offends Bert or the refugees...
*grin* Either that or it's time to go take our medication now... otherwise them FBI agents in white coats are gonna put me- I mean us back inside the padded -- click --
...are impossible -- unless we're talking about a nuclear or atomic engine. Math in a moment. That does not mean that a vehicle couldn't be designed with an overall engine system that would tromp all over the best current designs, andf maybe this new "nutating" engine is the right stuff -- don't know yet
The math for fuel economy is as follows: other than pure hydrogen, methane (CH4)(you know, natural gas -- most qty's derived from "dead dino dinner" aka antediluvian vegetation) at around 22,000 btu lb. LHV ["low heating value"], gasolines come in at about 20,500 btu/lb, diesel and jet fuels about 18,800 or so. [IIRC without the book in front of me.]
Using gasoline as the example fuel, you get about 6-1/2 lbs per gallon, or about 130K BTU. 1 HP = 2547 btu, so 135K/2547 equals about 50hp per gallon used per hour. Now then, my little subcompact gets about 35 mpg at that speed on the freeway, at around 12 hp in cruise gear. This particualr engine was rated about 25% thermally efficient under lab conditions. So even if my little car could get a 100% efficient engine (not possible in the real world), the max would be about 140 mpg.
Now then, pure hyrogen is pound for pound about three times more powerful as a fuel, but by the time you get the storage problems resolved, so far you've either added so much weight or drag, you've negated the fuel advantage.
Of course, if we were all flying around in low-drag H2 powered and lifted personal airships -- the weight component would go away.;-)
Finally, as has been noted in comments posted to other threads, H2 isn't an easy commodity to come by -- don't forget that 2000 sq. ft of solar panels will cost about the same as a medium size new car, or enough to buy fuel for my little car and a 35 mile round trip for somewhere around the next 20 years...
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By the way, the reason I mentioned penicillin had to do with the fact that Fleming originally discovered the microbe in the late '20s, but it wasn't until early in WW2 that technology came into being that allowed the mass production of the drug.
The relevance (which my underslept brain wasn't providing the other day) is that it seems like this new technique might have the same type of multiplicative effect on stem cell research that corn steep liquor had on penicilllin)
In fact, we studied a particularly remarkable cancerous cell line that was significant in that even though the patient died something like twenty five years ago (?), the particular cell line has remained viable (it still divides into new cells true to the original) since then.
I haven't decided how related this is, but penicillin only became a useful antibiotic only after a couple of other inventors were able to find a growth medium (corn steep liquor) that allowed large quantities of the organism to breed true.
So if the New Scientist article is correct and there is not a generational OR a quantity limiting factor in these cells, my thought is that this is a Noble-Prize level discovery.
Or from extending the same logic and copyrighting the file formats for MS office files, and that any attempts to sell software that decodes them outside of M$ operating systems are a violation of the DCMA, etc.?
Or am I just paranoid?
Dang. Read the article... Phillips patents expire in 2002 and 2003, and it would take that long just to get the litigation moving. We may be screwed.
- The RIAA tries to clobber Phillips with the DCMA,
- Phillips replies in effect saying "okay fine. Since your CD's don't comply to the CD-DA standard which we licensed to you in our patents, you are in violation of the licensing agreements which allowed you to use our patented technologies."
- Phillips sues the RIAA for breach of contract and obtains an injunction blocking future sales of all or just the incompatible CDs.
- RIAA companies can no longer sell a certain amount of music until the court case is finished.
- The RIAA folds on copy protection because they can't afford to lose that much money in sales.
Myself, I'd bet against any such thing happening, because Phillips would lose alot of money as well, but wouldn't it be nice if I was wrong?Until their damn EULA gets blown away in court and they get sued and lose bigtime for negligence in how they handle security concerns, I don't see any reason why M$ would change things -- doing things right might cut into profitibility more than the aforementioned business methods we all know and love...to hate.
Before the investment bubble burst last year, an unbelievable amount of fiber optic telco cable was laid, and IIRC, a lot of these lines have not even been activated, and won't be. Company after company has gone bankrupt trying to provide broadband and make money, even though most of us want the service.
Trouble is the damn RBOCs have managed to not only keep their local service monopolies pretty much intact but to strangle the up-and-comers at the connection point --- which was supposed to have been opened up by the 1996 telecommunications reform bill. Some legislators at the time grumbled that they had been sold a lie by the big telcos about the reforms, and promised to revisit the issue in the very next Congress... So here we are five years later... these same politicians continue to feed on the lobbyist cash cow, the RBOCS continue to rake in the profits on their existing poor service, and we wonder why nothing changes?
While some of Mr. Lessig's points strike true, in my view more of the problem has to do with big money corrupting the U.S. political process than any stranglehold on content because many of us would provide the content if we could get fairly priced access through-out the whole telco system.
When I read your post I started laughing so hard that I nearly choked and spit up the Dew I was drinking.
Damn, where's a moderator point when I need it?
Given how easily the ACLU gets up in arms about very small issues related to things like the 10 commandments on plaques, buildings, etc., why do you think that we aren't reading about the ACLU attacking bad legislation or proposed legislation(s) such as the DCMA, UCITA, the SSSCA (?), etc. ?
Texts I have read put the cooling waste for an IC engine at about 30%, which means that if the MIT devices could convert half of the heat wasted through the cooling system (not to mention the exhaust stream) to useful power, you would get a roughly sixty percent increase in fuel economy. Couple that with a hybrid system for autos or a diesel and now I'd even be interested.
By the way: top turbines now get around 40% thermal efficiency ratings , with combined cycle systems closing in on 60%. Big marine and stationary diesels can get close to 50%, but all of these are for huge engines/engine systems.
Too bad they haven't figured out how to downsize to much more moderate sizes without sacrificing the higher efficiencies offered by the big boys.
By the time a non -charged piston engine is up to about 8000 feet, it's lost about 20%-30% of its original sea level power, IIRC, so about the best use I've come up with for PV cell power so far would probably be for turbo and or light supercharging so that the damn fuel hogging engine up front gets more O2 to burn as the aircraft goes higher. Since drag goes down as the plane goes up, this would be a good thing in terms of fuel economizing. Still leaving more than enough extra extra engine power for the instruments, I think.
Thoughts anyone?
In terms of weight and bulk, there are existing studies for aircraft designs that use fuel cells as the nighttime power source for high altitude unmanned missions during the night, with the hydrogen being provided from surplace PV electricity generated during daylight hours. Interestingly enough, PV efficiency was less critical to aircraft size and mission profiles than fuel cell weight, as you noted.
The article mentions that fuel cells are twice as efficient as heat engines.
Well, sort of. From what I have read, the top fuel cells are between 60% and 70% efficient when used in with a bottoming cycle to use the excess heat produced by the cell. Top (big) diesel engines are between 40% and 50%, turbines (jet fuel is similar to diesel and kerosene) can be anywhere from horrible up to nearly 60% (bigger newer = better efficiency). I have yet to read the specs for a gasoline fired production engine getting much more than 30%-35%, so a higher capacity fuel cell does pretty darn good compared.
The critical thing to consider in terms of weight is that (depending on mission profile), if the engine is twice as efficient, you can carry half as much fuel. So even if the engine system weighs 60 pounds more (which would be make most general aviation engine designers shudder) for most general purpose aviation engines up to around 300-400 hp, for any flights requiring more than about 10 gallons of fuel, the overall aircraft weight would go down.
As far as propellers, designs are pretty much optimizable already because the aerodynamic shape isn't generally affected by the engine pulses. What is being lost between pulses is a slight amount of rotational speed in the blade, so an electrical prop wth the exact same aerodynamic design should have a very slight performance advantage over a piston driven prop... provided that the electrical system doesn't add so much weight that the drag induced by the added weight doesn't actually increase the power requirements for the aircraft. Props are actually pretty good at turning shaft energy into thrust, btw, with a good prop providing about 85-90% of the shaft horsepower as thrust.
Just my 2 cents worth. If I am wrong about any facts or figures, jump in and let me know... :-)
dang fingers. Accidentally hit the enter key with the focus on the submit button instead of the double quote before I got the HTML fixed. Sorry folks. :-(
The only phrase that was supposed to be bold was "which is only true for extremely large diesel engines." The rest was supposed to be just plain text.
As in I didn't say that my knowledge of thermodynamics was limited to one class. Which it isn't, by a factor of several years]. I only mentioned the first class because the knowledge is that elementary.
Out of curiousity, I looked at the VisionEngineer page, but it neglects to put the Gibbs energy, etc. into the overall exergy system -- which forces even a fuel cell to conform to known mathematical formulas and systems, none of which I want to type out and explain here.
You also accused my figures about IC engines to be drivel, because your source page shows that the state of the art for IC engines is somewhere above 52%.which is only true for extremely large diesel engines. If you take diesel engines out of the mix, the efficiency drops rather dramatically, and as far as I know there are no production automobile engines getting much more than 30%. The best non-turbine aero engines peak at around 37-38%. (By the way, I am humble enough to be willing to accept correction and update my knowledge base, if someone out there has figures showing something better)
Rather than resorting to the math, let me point out that one of the main by-products of a fuel cell is heat -- and in the case of the more highly efficient fuel cells, alot of it. In fact, so much heat that you can use the heat in a combined Air bottoming or Rankine Cycle engine system. That particular combination can theoretically get to about 75% thermal efficiency, but I haven't seen much that convinces me conclusively that it will go much higher.
So no matter what may be claimed, Fuel Cells are not 100% efficient and never will be. But we do agree that they have great potential to be a damn sight better than our current energy wasting IC engines.
Still, I was part of the team that made the first Apple II (at least in the State I lived in at the time) that could read from the screen back in 1981 -- to an "Echo II Speech Synthesizer" which IIRC came from Radio Shack.
We took some of our stuff to the linguistics department at the University across town, and of all things, had the darn machine speaking understandable Japanese (from Romaji, or romanized letters) within a few days because the Japanese language is consistent not only in phonetic translation but also in inflection. It still sounded like a machine, but that was a limitation of the sound chip's internal phoneme library in the Echo II. The same program with one of today's chips would have sounded very near normal.
Goes to show you how much more difficult spoken English is than most of us native speakers tend to realize, because I have yet to see a low cost implementation of a text to speech translator that was all that much better than what we were doing back in '81. (not that I have seen everything out there by the way -- I do have a life outside the PC world....occasionally :-)
It just so happens that the Carnot efficiency for the best current fuel cells is about double (50-60%) that of an internal combustion engine -- which is typically 25%-30%, not 30%-40% when you consider all losses. About the same as the best combined cycle (gas turbine + steam turbine) plants with a huge difference: fuel cells are small, where the best CC plants have always been in the 250 MW range or higher.
My source for info? a good introductory thermodynamics class.
Your point seems to be that "so long as a nation is willing to allow their citizens to be exploited, there will be healthy competition" -- instead of the idea being "so long as there is healthy competition, the playing field can be leveled". The fact is, governments can either work for or against healthy competition, capitalism can either work for or against healthy competition, and even "big business" can work for or against healthy competition. Gee, a theme here... leading to the further question of "what is healthy competition?"
My definition: healthy competition raises the level of all those participating in the competitive process -- which is where most big businesses and gov'ts fail. [Notice that I deliberately left out 'capitalists', because they are usually allied with one of the two other groups -- and it is often the capitalists who find ways of leveling the playing field -- by investing in the newer competitors to the established concerns.]
Then we come to the idea that taxes are something stolen from a citizen to help a business. Face it, in the 21st century, taxes are what we use to pay for services we all want, but usually with less efficiency and much more corruption than the private market would deliver. However -- no private company seems eager to provide an equality of services to all comers like fair governments are ostensibly supposed to do.
The system falls apart when instead of the common good, governments, capitalists, and big businesses only look to further their own interests, regardless of the damage done to those outside their respective domains. In other words, by participating in unhealthy competition in which one set of participants must lose (and lose regularly) in order for the other side to gain.
Thus my contention is that it isn't free trade that will "save the world", but equitable trade -- for example, that allows a well run farm in Iowa to get a fair price for his products without requiring that a well run farm in France go out of business. With true globalism -- both farms must improve to compete -- so the issue isn't trade -- but unfair trade -- which is where we come back into agreement.
IMO most multinational companies aren't interests in free trade-- they are interested in gaining unfair advantage for their own constituent interests. Usually making their alliance with government interests suspect at best and undeniably evil at worst.
I'd love to look at their stuff, but it has been years since I "spoke" Fortran fluently, having moved most of my old stuff to C or C++. Are there any converters out there that are up to snuff for this kind of work?
What I am not sure of is that I want the biggest companies acting as pitch men on the issue, because I for one do not trust the big companies to play fair one bit. Does anyone really think that the MPAA and the RIAA are interested in selling quality entertainment, as opposed to controlling the playing field? Remember, two of the largest corporate interests behind both the MPAA and the RIAA are AOL Time Warner and Disney... So why should I trust them to play fair with the administration or even development of a rating system, if they do not control my content directly?
My other issues are whether or not the blacklist is open for public review and change, and finally whether a website can offer more than one type of content under a given domain name. Which is why up to this point I oppose most sorts of filtering software is the lock-in -- I have to buy into using a proprietary, non-open list maintained by a corporate interest.
Secondarily, the so-called "white list" versions of blocking software have a similar problem -- someone has to rate the site to get on the list -- with all of the issues of list distribution or centralization, etc.
You know what works best for me? and doesn't require any new software or black/white list to work? Searching via Google with their 'safe" filters on, because 99% of the porn sites out there cross refer, and so when a new domain name gets a lot of hits from the known porn referrers, Google's algorithm correctly identifies the new site as, you guessed it -- another porn site. Easy, huh? Now all I have to do is get Google's attention for my own site....
If the banners are served by a different machine than the text, a second cookie could store some of these prefs so that all of the OSDN sites I visit should get the same higher value for the click, right?
What do y'all think?
It's a cool tool because not only does it get and prioritize links from a bunch of the top search engines, it also has a mode that will go through the list that it returns and get rid of any dead links.
I'd be interested in anybody's experiences with similar software, btw.
The web. Seriously. I have learned more about more science in more subjects in two or three years by researching online than I have ever been able to get out of a textbook. I have also found mentors in various knowledge areas, on-line tutorials and tools that are also far superior to the textbooks. The end result is that I am taking a couple of textbook based classes, namely Calculus and Thermodynamics, (because they relate to my specific interests.
So my best suggestion is for you to figure our what you'd really really like to know more about, and then jump out there on the web and start learning, and when you discover a specific knowledge base (like Calculus) for which there is a good textbook available, go ahead and get it.
The analysis below is predicated upon the reasonable conclusions that a) because Bert is more likely to be a closet Steelers fan (note the "steely" grimace...), and b) the Chiefs or Redskins could be conceivably be mistranslated into Arabic to represnt an oppressed people whose homeland has been confiscated by the evil invaders.
Our conclusion, developed using all of the available CIA supercomputers, is that the above over/under betting plot is designed to undermine the free world, that anyone who makes this bet in an off shore Internet casino is a terrorist, because that is the only bet that Osama can reasonably make because either he offends Bert or the refugees...
*grin* Either that or it's time to go take our medication now... otherwise them FBI agents in white coats are gonna put me- I mean us back inside the padded -- click --
The math for fuel economy is as follows: other than pure hydrogen, methane (CH4)(you know, natural gas -- most qty's derived from "dead dino dinner" aka antediluvian vegetation) at around 22,000 btu lb. LHV ["low heating value"], gasolines come in at about 20,500 btu/lb, diesel and jet fuels about 18,800 or so. [IIRC without the book in front of me.]
Using gasoline as the example fuel, you get about 6-1/2 lbs per gallon, or about 130K BTU. 1 HP = 2547 btu, so 135K/2547 equals about 50hp per gallon used per hour. Now then, my little subcompact gets about 35 mpg at that speed on the freeway, at around 12 hp in cruise gear. This particualr engine was rated about 25% thermally efficient under lab conditions. So even if my little car could get a 100% efficient engine (not possible in the real world), the max would be about 140 mpg.
Now then, pure hyrogen is pound for pound about three times more powerful as a fuel, but by the time you get the storage problems resolved, so far you've either added so much weight or drag, you've negated the fuel advantage.
Of course, if we were all flying around in low-drag H2 powered and lifted personal airships -- the weight component would go away. ;-)
Finally, as has been noted in comments posted to other threads, H2 isn't an easy commodity to come by -- don't forget that 2000 sq. ft of solar panels will cost about the same as a medium size new car, or enough to buy fuel for my little car and a 35 mile round trip for somewhere around the next 20 years...