I don't know if you know this or not, but "VR" is still something that is still being explored, and in some cases, actually used to solve problems.
Currently, "VR" is being used by large organizations, to do things that aren't otherwise easily possible - companies like Caterpillar use VR technology to simulate their tractors and place controls, and work out (via the simulation) where windows and controls need to be placed to allow the operator optimum view and comfort. The DOD has their "dismounted soldier" project, which aims to combine various "VR" technology (including new devices like 360 degree treadmills, developed for the project), real equipment, and other elements to train soldiers in a virtual combat simulation (while allowing other groups/soldiers from around the world to participate in the exercise with real equipment in the same simulation). Auto companies use "VR" technology for similar uses as Caterpillar does, to help design and build safer automobiles. Doctors are exploring virtual surgery - both for training purposes, as well as for endoscopic visualization use.
"VR" HMDs have become way more advanced than what the early 1990's offered - take a look at Kaiser Electro Optics lineup sometime, and be envious that you likely can't afford the top of the line models for a good FPS frag session (hell, what am I saying - even their bottom-of-the-barrel old tech is out of the price range of most/.ers). If you want to see what might come out for consumer use in the future (I can't imagine people would want to continue to play 3D FPS games and not look around - and don't say "it's too much work" - look at DDR, which is a much more active game), get an old Virtuality Visette 2 display and hook it up - old tech, 640x480 with 60 degree FOV - but with the full immersion - wow.
Finally, why do I keep referencing "VR" with quotes? Well, the fact is that "VR" is really the pop expression - you won't hear (much) the words "virtual reality" being thrown around in the simulation and data visualization industry. The last expression I heard was "virtual environment modeling", but that has been several years back - I don't believe the word "virtual" is used anymore in the industry, simply because of the negative connotations it has gained over the years since its "demise". The main thing holding back mass adoption of any of this technology by consumers is the lack of a "killer app". One would think 3D FPS games would fill this niche easily (the idea of a game system, similar to a Virtual Boy, but using full color OLED displays, the HMD being worn, cartridge or mini-disc software being inserted into a slot in the HMD, a cable from that to a joystick, the HMD using a passive mag tracked/tilt sensor package for sourceless 3DOF tracking, and simple tilt sensors ala a Cyberpuck - isn't too outlandish - but if it would sell or not?) - but for some reason, they just aren't (not yet, anyhow). 3D desktop/window managers aren't going to do it. The killer app has yet to arrive, but when (or if) it does, it might spawn a revolution in computer use not seen since the internet popped up (which, incidentally, also helped kill the first round of "VR" adoption - though had the hardware been more fully developed, could have enabled it instead)...
Actually, a friend of mine set this kind of deal up once. I never actually participated, but he would rent out a large storage room, and stuff would go in there. Certain piles/areas were things that were off limits to all but original owners, other things were free-for-all, and then there was the "library" section - where you would sign out books (every geek has a large collection of old computer books). He would collect rent for the space each month, and each person would get a key. Depending on your share of the rent, you would either get a community key, a master key, or no key at all. If you had a master key, you could remove the lock at will, and go in alone. Community keys or those without a key could only unlock the door if you had someone with a master key as well. Only a couple of people had master keys - for most cases you had to have someone with you to get stuff/trade stuff out.
As you note, use of a concentrating lens (or mirror setup, either way) on a solar cell, if at the focus, will quickly lead to the destruction of the solar cell. We are talking major heat at the focus - larger lens and mirror arrays can easily heat steel to the melting point - a solar cell would have no chance.
If you wanted to pursue this, though, you could use the lens to focus more light on the cell(s), provided that the cells are not at the focus, but are in front of or behind it, then mount the cells with heat conductive epoxy to a large heat sink (depending on thermal transfer rates, the heatsink may be either passive or active, if active, air-cooled or water-cooled). There have been experiments using these systems, but most have been abandoned because of the need to have an expensive and heavy (not to mention difficult to design) tracking system to track the sun from sun-up to sun-down (dual-axis tracking with end-of-day return to home).
If you wanted to use the focal point heat to change to electricity direction, look into building thermopiles - these can be built from various metals welded together (find a set of old Popular Mechanics Do-It-Yourself encyclopedias - ST-TI, page 2646, "Fun With a Homemade Thermopile") - use the heat of the solar concentrator on the the pile to generate electricity.
These piles work on the peltier principle - two disimilar metals, when heated, produce an electric current (similarly, when electricity is run through the wires, one wire gets cooler, the other hotter - which is why you should never use copper and alluminum wire together in a high-current electric circuit, like in houses, because of fire issues - this is also the principle behind a peltier cooler, BTW, but I don't think you would get much output if you used such a device in reverse, but hey - give it a shot!).
Finally, on the steam generator - you won't get great efficiency - you need to generate the steam, then pipe it away from the concentrator to the turbine or engine, which will incur heat losses through the piping. Then the mechanical losses, and finally the losses inherent in the generator. If you got 20% efficiency, I would be very surprised. I am not trying to discourage you, though - remember, any efficiency is good efficiency when it comes to solar, simply because the "fuel" (or input energy) is free - if you are only getting 20% efficiency, then build five collectors!
All of these designs have the issue of needing to track the sun - not impossible to build, but not easy, either. The electronics are dead simple, but the drive mechanism can be a pain because it has to move so slow. Then there is skew and "hunting" issues (though at the slow speed these are less likely to show).
I never meant to imply that it was impossible to have internet access from the poles - I know that it can be done, and has been done (heck, I think they are ever thinking about a trans-antartica fiber line, aren't they?).
What I was meaning to convey was that compared to the poles, the Black Rock Desert isn't very isolated (but it is the most isolated and desolated place I have ever been) - the closest towns (Gerlach and Empire) aren't that far away (not that they are huge places) - and Reno isn't much further.
With that said, it might actually be easier to get internet access at the south pole than it would be to set it up at Burning Man (or another desolate or isolated temporary camping event), simply because at the south pole - it is already in place, everything is set up and working, and it is maintenance after that (still no mean feat). For temporary or transient uses, though - setting up to connect to the internet can be a real challenge - what tech is best to use (wired, wireless, sattelite, lasercomm), clear line-of-sight for those connections that require it (or the ability to set up repeaters on mountains, etc), and the conditions of the environment (in the case of Burning Man - how well will the equipment stand up to 40-110 degree F temperature swings in a blowing flour-dust consistency environment for a week+?)...
It has been a while, and I should get back in my shop to finish it up to "testing" phase - but if you look on my site (under "Projects"), you will see the "experiment" I have been working on for a while now.
I am building a recumbent electric vehicle, built from bike parts. So far, I have the majority of the vehicle complete. I still need to mount the motor, attach the chain, get the batteries hooked up (I am also thinking about a motor controller, but I will probably go with a simple high-current relay at first - motor controllers aren't cheap). Later, I will need to get low-tread tires (more tread=more drag=lower efficiency=less miles per charge). If the motor works out (pretty powerful for its size), I also need new bearings installed on it.
It has been a very fun project. Google around for "electric bicycle" and "homemade recumbent" for other ideas. I had originally thought about using a chainsaw/weed trimmer engine - but due to noise and other reasons, decided against it. If you did use such an engine, try to get a 4-cycle. It will be more expensive, but it runs quieter, and there is no mixing of oil/fuel - plue it is easy to port the carb on such an engine so that it can run on propane (basically, the ports are driller larger, and a regulator is installed).
I also like the idea of electric, because of the possibility (if they ever get here with it) of using scavenged "laptop fuel cells" to generate the power needed. Another idea would be to scavenge parts from cheap gopeds (both gas and electric) that litter the market today (many engines and motors are sold on ebay all the time).
There is also the option of buying an electric bike, then either using it as-is, or stripping it down and rebuilding it as a recumbent...
I am not sure where to start with this - first off, calling SuSE to figure out hardware from Compaq, and he starts talking about Windows to configure the BIOS.
This has train wreck written all over it...
So tell me, why didn't you call Compaq in the first place (it is an issue with their hardware, after all)?
Last year was my first burn - of the many, many things that impressed me, the fact that I was able to email from such a remote place (ok, not that remote - not like Antarctica or something) is something I will never forget. I would say that if you want to find out how to do this - you might start here...
Which will likely never be implemented by Goodyear (or other companies) on their gas nozzle systems, simply because it would obviously eat into profits, angering their shareholders...
Does anybody here remember when gas pump handles were bare metal, not covered with rubber/plastic? I remember these, and while I don't know exactly why they switched, it probably had to do with comfort, most likely (to get more women pumping their own gas? to keep the sun's heat from making the handle unbearably hot?). Gas pumps are typically grounded anyhow, so when you reached for the pump, and static charge you had would be grounded away before you started pumping. However, when you pump gas now, you still have that possibility of having a charge, because the rubber/plastic on the handle insulates you...
So - why not a couple or three metal "knubbies" over the top outside of the handle, riveted or otherwise attached through the plastic to the grounded metal handle? You would still have the plastic to preserve comfort, and the nubs would act as a ground...
Now, this wouldn't stop other problems with static electricity (ie, the charge built up in the vehicle, or elsewhere), but it would definitely help in some manner. However, we are likely never to see it, unless required by law, or through a public outcry (and I doubt that is going to happen - this just doesn't affect enough people to mobilize others) - because it would eat into the bottom line...
and, before some smartass starts telling me the facts about gas vapors and hot coals - let me tell you this : Hollywood aside, you can't light gasoline w/ a cigarette, nor have I ever run across a case where you could light vapors w/ them either. Tobacco just doesn't burn hot enough.
You know, I have heard the same thing, but I have the opposite personal experience as well: Pour some gas in a pan or something, toss a burning match in, and it will likely hit the gas and extinguish itself. I am not sure if you have to fill the container up to the top (ie, no well for vapors to form in), or what - never did any empirical testing of this...
On the other hand, in my younger and stupider days, I remember going camping, and it was drizzling rain. I was at a campsite with a steel fire-ring area. Gathered up some wood, but it was mostly wet. Needed/wanted a fire - so I pulled out the gas can (didn't have any other flammable substance with me), sloshed a bit on the wood, set the can back a good distance away, stood back, lit a match, and tossed it in - let's just say the fire started, and no one was injured, nor did the campground burn down...
So, anybody here think...
on
Metal Velcro
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· Score: 4, Interesting
...this stuff will be stronger than JB-Weld?
JB-Weld, for those of you who don't know, is probably number one in the list of tools for rednecks and others (right next to duct tape, baling wire, and bubblegum) who need to make a repair fairly quickly, and want it to remain in place.
JB-Weld is strong - very strong. It is a two-part epoxy (comes in slow and quick setting versions) which I have yet to find an equal to.
My brother-in-law repaired the cracked housing of a blower off the diesel engine on his 10-wheel dump truck (it was alluminum, and he didn't have the equipment to properly weld it) - that repair lasted 5 years before he "retired" the truck (actually, the engine block cracked), probably would have lasted even longer...
I use it all the time - if it is something that I can't weld but I need to have it stay together (under heat, pressure, vibration, or other high stress especially) - JB Weld is my first choice. I have seen it hold shit together where you would swear it would have to be welded (more or less, it is - just an epoxy "weld") to stay together.
Now, I know this "metal velcro" is supposed to be an "industrial process" - meaning it will likely never be available for home use in the near future. I also know there are industrial epoxies. I wonder if any of them would beat the pants off of JB-Weld - though I wonder if JB is already an industrial epoxy packaged for "small project" use - I wish I could buy that stuff in larger quantities...
Actually, we would likely be screaming "why the hell is he trying so many damn different materials", instead of using scientific methods to discover the proper material thru hypothesis and experiment...
I am pretty certain that most people don't vote their conscience, and instead vote "for their party", or for "who is popular".
My "insight" is seeing how people vote for various candidates, talking to people about who they voted for and why, the statements other makes in this forum (as well as others), etc.
No, I do not think I am the only one who understands what is going on (hell, half the time I wonder if I even understand it, or if it is even capable of being understood!). I hope and "pray" every day that there are enough people out there who do understand to make a difference. Every day, though, I see the results of what can either only be incompetance, or worse, willfulness to bypass the "system" in ways which advance personal and/or partisan agendas.
Finally, AC - be a man (or woman, whatever you are) - and post something to me without hiding behind the "coward" label. I am about freedom - I never said "don't vote for Bush" - I explicitly stated that everyone needs to look closely at all of their options, and vote for whichever one they think is best - ie, voting their conscience. How is this "communistic"? Simply because one should look into third parties (not looking into them is as bad as only considering them - an informed voter should look into all of his or her options!)?
Damn - I wonder if I should be responding at all to such an anonymous post, let alone one obviously penned by an ignorant...
That final line is what is known as an "off-the-cuff 'jest'" - humor, if you will.
Which is beside the point. We are most likely both correct (shocking!) - the CDC is right in that food with possible fecal coliform matter contamination, such as ground beef, needs to be cooked to a temperature of 160 degrees F (for a minimum of 10 minutes). Other sources, however, indicate that in a methane digester, an environment completely unlike that of ground beef, that such fecal coliform bacteria will be killed by much lower temperatures in the digester, if maintained for longer periods of time, in this case, between 5-30 days, depending on temperature.
Look at it this way - you can cook a roast at 150 degrees F or 350 degrees F - both will cook the roast to the same level of "doneness", one just takes longer than the other. The same principle is at work here: cooking longer, at lower temperatures will kill the fecal coliform bacteria just as effectively as cooking at high temperatures for shorter amounts of time.
In fact, I will issue you a challenge (hell, the results would be useful for everyone):
1. Obtain some ground beef. 2. Seperate said ground beef into three equal amounts. 3. Make one amount your control amount - put it in the refrigerator. 4. For the other two amounts, cook one at 105 degrees F for 5 days. For the other, cook it at 160 degrees F for a couple of hours (or until it reaches on the interior 160 degrees F, for 10 minutes). 5. Take labeled samples of each and have them analyzed for levels of fecal colliform bacteria (specifically e. coli) at a reputable testing lab (heck, have the CDC do it if they can spare the time).
My hypothesis is that you are likely to find equal levels of e. coli in both of the two "cooked" samples (whether that level will be zero or low, is unknown), and who knows what will be in the uncooked control (likely higher levels).
There you go - a simple scientific experiment (maybe not cheap, for the testing - but simple nonetheless). Actually, if you really wanted to perform this experiment properly, you would want to replicate the conditions in a methane digester - but that would likely be difficult (and smelly?) for a home scientist to perform...
Actually, isn't this a style used by writers in Germany (I can't remember what the style is called, but I do know it has a format like this, and tends to date from a long while back) - can anyone back me up on this?
I agree this is an important property (having worked on more than a few PC's and "losing" screws by having them fall off my screwdriver while cursing, I can attest to this!). I also agree with the "anti-strip" feature such a head shape would have. There is always plenty of room for improvement in fastner design - but you are always going to run up against the "tried and true" (regardless of how well they work in practice), at least until enough time passes to render them completely obsolete (and for fasteners, that can be a very long time - it hasn't been too long in the history of things that nails look like they do today - and that is a very old fastening device).
Hardly similar to the enviroment found in a methane digester. Googling a bit does bring up the oft-cited "cook your burgers to 160F to kill e. coli". Digging deeper into those links I found, I ran across this page:
Within this paper, it notes in a table (toward the bottom) that "fecal coliform" bacteria (of which, e. coli is one) tend to live less than 5 days (for tropical climate - higher moisture, 20-30 C, or 68-86 F), and certainly less than 30 days (for temperate climate - lower moisture, 10-15 C, or 50-59 F), in "wet sludge" - both of which are temperature ranges well below that of a properly operating methane digester.
Lastly, no one is advocating eating of the sludge from a digester...
AC, when I spoke of using solar power to "crack" water, I wasn't speaking of misguided (at least until we get more efficient cells) use of solar cells.
What I was referring to was using solar concentrator towers to superheat water to steam (under very high pressure), then passing this steam over iron heated red-hot in another solar concentrator tower...
This form of hydrogen production (albeit without the use of solar power input) was used in the 1800's to generate hydrogen for the sport of ballooning (ie, aerostats in the vernacular of the time). At the time, there wasn't a way to generate hydrogen in sufficient quantities at a fast enough rate to fill one of the balloons - the best method used sulfuric or hydrochloric acid in barrels (!) into which was dumped iron, the reaction generated a lot of heat and hydrogen (among other things) - as such, there were at times explosions and other calamities which occurred as a result.
It was soon found that passing superheated steam over red hot iron would generate hydrogen in sufficient quantities for the sport, so the sport soon switched to that method.
A similar method is used today in refineries to break the hydrocarbons up into hydrogen - it uses superheated steam as well, but I haven't been able to find a complete description of the process. It may be that this process of using steam only isn't done, because more hydrogen can be currently released from oil than from water using the method...
This number is otherwise known as the "golden ratio", it was discovered back in classical Greece and it was known to be the most aesthetically pleasing of all ratios. The Parthenon in Athens was built so that its length and width were dictated by this ratio, it was also used by many Renaissance artists to draw the human body so it seems "perfect".
These supposed "truisms" are actually mostly false - most are due to attempting to find the ratio where it didn't exist in the first place (ala Hoagland's "City of Mars" "mathematical layout", the Great Pyramid's "mathematical layout", etc)...
If you want a great book on the subject of the phi, check out the book "The Golden Ratio" by Mario Livio (ISBN 0-7679-0816-3) to learn more about it than you would ever care to know...
It might have to do with "farm mentality" - not that it is wrong.
Basically, both phillips and standard screws/screwdrivers can be easily made on a farm (or in the garage or shop) with a minimum of special tools - a standard screw can simply be notched on one end, and a flat piece of metal can turn it. Same with phillips (two notches and a small dimple, and a nail's pointed end reworked with some common tools and grinder to give you a "phillips" screwdriver).
Such cannot be said with other forms of fasteners. I have never heard of "Robertson screws" (hmm - googling shows a square inset with square bits - screwdrivers could be improvised on the farm, but the the screws themselves couldn't - still, I have seen such screws, now I know the name for them - thanks!) - personally I prefer Torx (at least those can sometime be removed with hex bits and wrenches of the right size).
Your septic tank isn't an ideal, anaroebic environment for this kind of system - it isn't designed properly.
For a methane digester to work properly, it not only needs crap (and a lot of it), it also needs proper "food" and most importantly, insulation, to keep it working. It has to be kept at the right temperature and the right N2 and CO2 mixture levels - monitoring is essential. Once you get it at the right temperature, and keep it there (95-105 F), you can feed in other biowastes - table scraps, lawn clippings, etc (plus a little extra water every now and then). Basically, it works like a liquidy compost pile (and yes, it needs to be stirred every now and then, just like a compost pile - most digesters use a motor powered stiring "paddle" - like an oversized paint mixer).
A septic tank has no insulation, and it generally isn't sealed well enough to keep the outside air out - plus it doesn't have the pressure relief and other mechanisms needed for proper gas delivery.
That isn't to say you couldn't build a methane digester for a home - but you couldn't just pump the water from the toilets into one, either - too much water in a digester is a bad thing - you would need to figure out a way to either separate the water from the waste (talk to a sanitation engineer for that one), or figure out a way to build a toilet that doesn't use water to flush (I would think some kind of "outhouse" style toilet could be made to do this well - but it wouldn't work in a home, obviously).
Your idea has merit - but it would have to be a system (both inside the house and outside) designed from the ground up - it probably wouldn't be something that could be retrofitted. Furthermore, you would have to keep a sharp eye on monitoring it - if it is something you really want to do, that wouldn't be a problem - but for most people, it would be too time consuming and technical to deal with (similar to a swimming pool, BTW, so maybe there is a whole new industry of service workers waiting there - methane digester servicing, anyone?)...
I agree with you that the quote is misleading - but if you do some research into the theory of "peak oil" (Hubbert's Peak), which is an accepted theory by the oil companies (indeed, the theory is based on algorithms and calculations done by one of their late scientists), which they do not deny themselves, even in recent trade magazines - you will find that this quote isn't really wrong, we have already (likely around 2002-2003) "peaked", and are beginning the decline.
This theory does not say we will run out of oil, but that recoverable oil will take more and more energy to recover, until it reaches a point where it takes more energy to recover a barrel of oil, than would be provided by that barrel of recovered oil (basically thus becoming an energy sink).
The theory predicted that in 30 years (from roughly the 1970s), the oil that is recoverable without much in the way of input energy (that is, the oil recovered gives back more energy than was required to get it), that those days would be over in about 30 years (hence, the peak), and that world oil demand, coupled with falling recoverable oil reserves, would then lead to a gradual decline.
One could argue that what we are seeing in regards to the conflicts in the Middle East are one result of this (he who controls the last drops of oil will be in a very well off position both economically and politically in the future). If this is true, what is happenning now is only the tip of the iceberg - expect in the future even higher gas prices (like they have ever dropped - ha!), higher food prices, possible "plagues" of insects and disease in crops (since chemical controls made from petroleum sources will get more expensive, and either will be less used, or not used altogether), higher costs for electric, water, and sewage treatment...
Not too mention more wars, possibly world wars, as the countries which need, or perceive the need (like China) for this energy look to take it away from those (USA?) who control it...
Nearly all of western society is dependent with a capital "D" on oil - unless we change or augment it with a different energy source (hydrogen isn't it, unless we somehow could build fusion reactors to crack seawater - though I have posted many times how this might be able to be accomplished via solar energy, and have yet to be refuted though I beg for it - because my answer seems so simplistic as to be naive, thus likely having problems with it), we are likely to be screwed in another 20-30 years...
Nah! Forget about the tractor spreading it! You should try being on the tractor loading it into a dump truck, in the wintertime (when the piles "steam" putridly in the cold air), when it is raining, and the wind is blowing.
Word of caution: don't breath through your mouth unless you need the extra fiber...
At the above link, you will find the following little tidbit:
Because manure digestion is anaerobic, most weed seeds and pathogens are killed during the process. Pathogens like E.coli, Salmonella, and Cryptosporidium can't survive the high temperature of heated digester. Fecal coliform bacteria numbers in the biosolids are only about one percent of those in fresh and stored manure, lowering the potential for this source of water pollution.
Forget about "mutated e. coli" - read a little before making posts demonstrating your ignorance...
No, I did not just come to this conclusion - I am merely restating what most of us already know...
Why is it that these "mobs" of people can "come together", promoting violence, hatred, and fighting - amongst apparently (mostly) consenting adults (and disturbingly, children) - for what appear to be absolutely no reason at all! At best (in the cases of hooligans), it is over who's sports team is better!
Meanwhile, in the supposedly real world, we have people of all sorts (everywhere!), who are "arranging" their own sorts of "flash mobs" to kill each other over who knows what reason (is it oil? is it terrorism? is it entertainment?) - but no one is organizing "flash mobs" of protestors to stand against these attrocities against civilization!
We are living in a world of hate, anger, war and terror - yet I would bet that if you could poll each country's citizenry, likely 99% would say "yeah, I want peace, no fighting, just leave us alone, we'll leave you alone, and if you come visit, we can enjoy a brew down at the pub together"...
A sane society would each see the madmen for who they are, and get rid of them quickly and effectively, rather than letting them supposedly "lead" each other into conflicts that the majority don't really want.
You can't say to me that people really want war. You can't say to me that people really want body bags, sons and daughters missing limbs coming home, haunted looks in their eyes. You can't say to me people want to see each other blown up in a spray of bloody particles. Yet we continue to do what only a mad society would do.
Damnit! If only "The Day After Tommorow" wasn't a movie - we need a good cleaning to remind us of what is truely important (that, or just to show us, to our faces, what animals we really are - as if the current state of affairs can't do that)...
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Currently, "VR" is being used by large organizations, to do things that aren't otherwise easily possible - companies like Caterpillar use VR technology to simulate their tractors and place controls, and work out (via the simulation) where windows and controls need to be placed to allow the operator optimum view and comfort. The DOD has their "dismounted soldier" project, which aims to combine various "VR" technology (including new devices like 360 degree treadmills, developed for the project), real equipment, and other elements to train soldiers in a virtual combat simulation (while allowing other groups/soldiers from around the world to participate in the exercise with real equipment in the same simulation). Auto companies use "VR" technology for similar uses as Caterpillar does, to help design and build safer automobiles. Doctors are exploring virtual surgery - both for training purposes, as well as for endoscopic visualization use.
"VR" HMDs have become way more advanced than what the early 1990's offered - take a look at Kaiser Electro Optics lineup sometime, and be envious that you likely can't afford the top of the line models for a good FPS frag session (hell, what am I saying - even their bottom-of-the-barrel old tech is out of the price range of most /.ers). If you want to see what might come out for consumer use in the future (I can't imagine people would want to continue to play 3D FPS games and not look around - and don't say "it's too much work" - look at DDR, which is a much more active game), get an old Virtuality Visette 2 display and hook it up - old tech, 640x480 with 60 degree FOV - but with the full immersion - wow.
Finally, why do I keep referencing "VR" with quotes? Well, the fact is that "VR" is really the pop expression - you won't hear (much) the words "virtual reality" being thrown around in the simulation and data visualization industry. The last expression I heard was "virtual environment modeling", but that has been several years back - I don't believe the word "virtual" is used anymore in the industry, simply because of the negative connotations it has gained over the years since its "demise". The main thing holding back mass adoption of any of this technology by consumers is the lack of a "killer app". One would think 3D FPS games would fill this niche easily (the idea of a game system, similar to a Virtual Boy, but using full color OLED displays, the HMD being worn, cartridge or mini-disc software being inserted into a slot in the HMD, a cable from that to a joystick, the HMD using a passive mag tracked/tilt sensor package for sourceless 3DOF tracking, and simple tilt sensors ala a Cyberpuck - isn't too outlandish - but if it would sell or not?) - but for some reason, they just aren't (not yet, anyhow). 3D desktop/window managers aren't going to do it. The killer app has yet to arrive, but when (or if) it does, it might spawn a revolution in computer use not seen since the internet popped up (which, incidentally, also helped kill the first round of "VR" adoption - though had the hardware been more fully developed, could have enabled it instead)...
Actually, a friend of mine set this kind of deal up once. I never actually participated, but he would rent out a large storage room, and stuff would go in there. Certain piles/areas were things that were off limits to all but original owners, other things were free-for-all, and then there was the "library" section - where you would sign out books (every geek has a large collection of old computer books). He would collect rent for the space each month, and each person would get a key. Depending on your share of the rent, you would either get a community key, a master key, or no key at all. If you had a master key, you could remove the lock at will, and go in alone. Community keys or those without a key could only unlock the door if you had someone with a master key as well. Only a couple of people had master keys - for most cases you had to have someone with you to get stuff/trade stuff out.
If you wanted to pursue this, though, you could use the lens to focus more light on the cell(s), provided that the cells are not at the focus, but are in front of or behind it, then mount the cells with heat conductive epoxy to a large heat sink (depending on thermal transfer rates, the heatsink may be either passive or active, if active, air-cooled or water-cooled). There have been experiments using these systems, but most have been abandoned because of the need to have an expensive and heavy (not to mention difficult to design) tracking system to track the sun from sun-up to sun-down (dual-axis tracking with end-of-day return to home).
If you wanted to use the focal point heat to change to electricity direction, look into building thermopiles - these can be built from various metals welded together (find a set of old Popular Mechanics Do-It-Yourself encyclopedias - ST-TI, page 2646, "Fun With a Homemade Thermopile") - use the heat of the solar concentrator on the the pile to generate electricity.
These piles work on the peltier principle - two disimilar metals, when heated, produce an electric current (similarly, when electricity is run through the wires, one wire gets cooler, the other hotter - which is why you should never use copper and alluminum wire together in a high-current electric circuit, like in houses, because of fire issues - this is also the principle behind a peltier cooler, BTW, but I don't think you would get much output if you used such a device in reverse, but hey - give it a shot!).
Finally, on the steam generator - you won't get great efficiency - you need to generate the steam, then pipe it away from the concentrator to the turbine or engine, which will incur heat losses through the piping. Then the mechanical losses, and finally the losses inherent in the generator. If you got 20% efficiency, I would be very surprised. I am not trying to discourage you, though - remember, any efficiency is good efficiency when it comes to solar, simply because the "fuel" (or input energy) is free - if you are only getting 20% efficiency, then build five collectors!
All of these designs have the issue of needing to track the sun - not impossible to build, but not easy, either. The electronics are dead simple, but the drive mechanism can be a pain because it has to move so slow. Then there is skew and "hunting" issues (though at the slow speed these are less likely to show).
What I was meaning to convey was that compared to the poles, the Black Rock Desert isn't very isolated (but it is the most isolated and desolated place I have ever been) - the closest towns (Gerlach and Empire) aren't that far away (not that they are huge places) - and Reno isn't much further.
With that said, it might actually be easier to get internet access at the south pole than it would be to set it up at Burning Man (or another desolate or isolated temporary camping event), simply because at the south pole - it is already in place, everything is set up and working, and it is maintenance after that (still no mean feat). For temporary or transient uses, though - setting up to connect to the internet can be a real challenge - what tech is best to use (wired, wireless, sattelite, lasercomm), clear line-of-sight for those connections that require it (or the ability to set up repeaters on mountains, etc), and the conditions of the environment (in the case of Burning Man - how well will the equipment stand up to 40-110 degree F temperature swings in a blowing flour-dust consistency environment for a week+?)...
I am building a recumbent electric vehicle, built from bike parts. So far, I have the majority of the vehicle complete. I still need to mount the motor, attach the chain, get the batteries hooked up (I am also thinking about a motor controller, but I will probably go with a simple high-current relay at first - motor controllers aren't cheap). Later, I will need to get low-tread tires (more tread=more drag=lower efficiency=less miles per charge). If the motor works out (pretty powerful for its size), I also need new bearings installed on it.
It has been a very fun project. Google around for "electric bicycle" and "homemade recumbent" for other ideas. I had originally thought about using a chainsaw/weed trimmer engine - but due to noise and other reasons, decided against it. If you did use such an engine, try to get a 4-cycle. It will be more expensive, but it runs quieter, and there is no mixing of oil/fuel - plue it is easy to port the carb on such an engine so that it can run on propane (basically, the ports are driller larger, and a regulator is installed).
I also like the idea of electric, because of the possibility (if they ever get here with it) of using scavenged "laptop fuel cells" to generate the power needed. Another idea would be to scavenge parts from cheap gopeds (both gas and electric) that litter the market today (many engines and motors are sold on ebay all the time).
There is also the option of buying an electric bike, then either using it as-is, or stripping it down and rebuilding it as a recumbent...
This has train wreck written all over it...
So tell me, why didn't you call Compaq in the first place (it is an issue with their hardware, after all)?
Last year was my first burn - of the many, many things that impressed me, the fact that I was able to email from such a remote place (ok, not that remote - not like Antarctica or something) is something I will never forget. I would say that if you want to find out how to do this - you might start here...
Does anybody here remember when gas pump handles were bare metal, not covered with rubber/plastic? I remember these, and while I don't know exactly why they switched, it probably had to do with comfort, most likely (to get more women pumping their own gas? to keep the sun's heat from making the handle unbearably hot?). Gas pumps are typically grounded anyhow, so when you reached for the pump, and static charge you had would be grounded away before you started pumping. However, when you pump gas now, you still have that possibility of having a charge, because the rubber/plastic on the handle insulates you...
So - why not a couple or three metal "knubbies" over the top outside of the handle, riveted or otherwise attached through the plastic to the grounded metal handle? You would still have the plastic to preserve comfort, and the nubs would act as a ground...
Now, this wouldn't stop other problems with static electricity (ie, the charge built up in the vehicle, or elsewhere), but it would definitely help in some manner. However, we are likely never to see it, unless required by law, or through a public outcry (and I doubt that is going to happen - this just doesn't affect enough people to mobilize others) - because it would eat into the bottom line...
You know, I have heard the same thing, but I have the opposite personal experience as well: Pour some gas in a pan or something, toss a burning match in, and it will likely hit the gas and extinguish itself. I am not sure if you have to fill the container up to the top (ie, no well for vapors to form in), or what - never did any empirical testing of this...
On the other hand, in my younger and stupider days, I remember going camping, and it was drizzling rain. I was at a campsite with a steel fire-ring area. Gathered up some wood, but it was mostly wet. Needed/wanted a fire - so I pulled out the gas can (didn't have any other flammable substance with me), sloshed a bit on the wood, set the can back a good distance away, stood back, lit a match, and tossed it in - let's just say the fire started, and no one was injured, nor did the campground burn down...
JB-Weld, for those of you who don't know, is probably number one in the list of tools for rednecks and others (right next to duct tape, baling wire, and bubblegum) who need to make a repair fairly quickly, and want it to remain in place.
JB-Weld is strong - very strong. It is a two-part epoxy (comes in slow and quick setting versions) which I have yet to find an equal to.
My brother-in-law repaired the cracked housing of a blower off the diesel engine on his 10-wheel dump truck (it was alluminum, and he didn't have the equipment to properly weld it) - that repair lasted 5 years before he "retired" the truck (actually, the engine block cracked), probably would have lasted even longer...
I use it all the time - if it is something that I can't weld but I need to have it stay together (under heat, pressure, vibration, or other high stress especially) - JB Weld is my first choice. I have seen it hold shit together where you would swear it would have to be welded (more or less, it is - just an epoxy "weld") to stay together.
Now, I know this "metal velcro" is supposed to be an "industrial process" - meaning it will likely never be available for home use in the near future. I also know there are industrial epoxies. I wonder if any of them would beat the pants off of JB-Weld - though I wonder if JB is already an industrial epoxy packaged for "small project" use - I wish I could buy that stuff in larger quantities...
Actually, we would likely be screaming "why the hell is he trying so many damn different materials", instead of using scientific methods to discover the proper material thru hypothesis and experiment...
My "insight" is seeing how people vote for various candidates, talking to people about who they voted for and why, the statements other makes in this forum (as well as others), etc.
No, I do not think I am the only one who understands what is going on (hell, half the time I wonder if I even understand it, or if it is even capable of being understood!). I hope and "pray" every day that there are enough people out there who do understand to make a difference. Every day, though, I see the results of what can either only be incompetance, or worse, willfulness to bypass the "system" in ways which advance personal and/or partisan agendas.
Finally, AC - be a man (or woman, whatever you are) - and post something to me without hiding behind the "coward" label. I am about freedom - I never said "don't vote for Bush" - I explicitly stated that everyone needs to look closely at all of their options, and vote for whichever one they think is best - ie, voting their conscience. How is this "communistic"? Simply because one should look into third parties (not looking into them is as bad as only considering them - an informed voter should look into all of his or her options!)?
Damn - I wonder if I should be responding at all to such an anonymous post, let alone one obviously penned by an ignorant...
Which is beside the point. We are most likely both correct (shocking!) - the CDC is right in that food with possible fecal coliform matter contamination, such as ground beef, needs to be cooked to a temperature of 160 degrees F (for a minimum of 10 minutes). Other sources, however, indicate that in a methane digester, an environment completely unlike that of ground beef, that such fecal coliform bacteria will be killed by much lower temperatures in the digester, if maintained for longer periods of time, in this case, between 5-30 days, depending on temperature.
Look at it this way - you can cook a roast at 150 degrees F or 350 degrees F - both will cook the roast to the same level of "doneness", one just takes longer than the other. The same principle is at work here: cooking longer, at lower temperatures will kill the fecal coliform bacteria just as effectively as cooking at high temperatures for shorter amounts of time.
In fact, I will issue you a challenge (hell, the results would be useful for everyone):
1. Obtain some ground beef. .
2. Seperate said ground beef into three equal amounts
3. Make one amount your control amount - put it in the refrigerator.
4. For the other two amounts, cook one at 105 degrees F for 5 days. For the other, cook it at 160 degrees F for a couple of hours (or until it reaches on the interior 160 degrees F, for 10 minutes).
5. Take labeled samples of each and have them analyzed for levels of fecal colliform bacteria (specifically e. coli) at a reputable testing lab (heck, have the CDC do it if they can spare the time).
My hypothesis is that you are likely to find equal levels of e. coli in both of the two "cooked" samples (whether that level will be zero or low, is unknown), and who knows what will be in the uncooked control (likely higher levels).
There you go - a simple scientific experiment (maybe not cheap, for the testing - but simple nonetheless). Actually, if you really wanted to perform this experiment properly, you would want to replicate the conditions in a methane digester - but that would likely be difficult (and smelly?) for a home scientist to perform...
Actually, isn't this a style used by writers in Germany (I can't remember what the style is called, but I do know it has a format like this, and tends to date from a long while back) - can anyone back me up on this?
I agree this is an important property (having worked on more than a few PC's and "losing" screws by having them fall off my screwdriver while cursing, I can attest to this!). I also agree with the "anti-strip" feature such a head shape would have. There is always plenty of room for improvement in fastner design - but you are always going to run up against the "tried and true" (regardless of how well they work in practice), at least until enough time passes to render them completely obsolete (and for fasteners, that can be a very long time - it hasn't been too long in the history of things that nails look like they do today - and that is a very old fastening device).
The microbiology of sewage sludge and Farm Manure
Within this paper, it notes in a table (toward the bottom) that "fecal coliform" bacteria (of which, e. coli is one) tend to live less than 5 days (for tropical climate - higher moisture, 20-30 C, or 68-86 F), and certainly less than 30 days (for temperate climate - lower moisture, 10-15 C, or 50-59 F), in "wet sludge" - both of which are temperature ranges well below that of a properly operating methane digester.
Lastly, no one is advocating eating of the sludge from a digester...
What I was referring to was using solar concentrator towers to superheat water to steam (under very high pressure), then passing this steam over iron heated red-hot in another solar concentrator tower...
This form of hydrogen production (albeit without the use of solar power input) was used in the 1800's to generate hydrogen for the sport of ballooning (ie, aerostats in the vernacular of the time). At the time, there wasn't a way to generate hydrogen in sufficient quantities at a fast enough rate to fill one of the balloons - the best method used sulfuric or hydrochloric acid in barrels (!) into which was dumped iron, the reaction generated a lot of heat and hydrogen (among other things) - as such, there were at times explosions and other calamities which occurred as a result.
It was soon found that passing superheated steam over red hot iron would generate hydrogen in sufficient quantities for the sport, so the sport soon switched to that method.
A similar method is used today in refineries to break the hydrocarbons up into hydrogen - it uses superheated steam as well, but I haven't been able to find a complete description of the process. It may be that this process of using steam only isn't done, because more hydrogen can be currently released from oil than from water using the method...
These supposed "truisms" are actually mostly false - most are due to attempting to find the ratio where it didn't exist in the first place (ala Hoagland's "City of Mars" "mathematical layout", the Great Pyramid's "mathematical layout", etc)...
If you want a great book on the subject of the phi, check out the book "The Golden Ratio" by Mario Livio (ISBN 0-7679-0816-3) to learn more about it than you would ever care to know...
Basically, both phillips and standard screws/screwdrivers can be easily made on a farm (or in the garage or shop) with a minimum of special tools - a standard screw can simply be notched on one end, and a flat piece of metal can turn it. Same with phillips (two notches and a small dimple, and a nail's pointed end reworked with some common tools and grinder to give you a "phillips" screwdriver).
Such cannot be said with other forms of fasteners. I have never heard of "Robertson screws" (hmm - googling shows a square inset with square bits - screwdrivers could be improvised on the farm, but the the screws themselves couldn't - still, I have seen such screws, now I know the name for them - thanks!) - personally I prefer Torx (at least those can sometime be removed with hex bits and wrenches of the right size).
For a methane digester to work properly, it not only needs crap (and a lot of it), it also needs proper "food" and most importantly, insulation, to keep it working. It has to be kept at the right temperature and the right N2 and CO2 mixture levels - monitoring is essential. Once you get it at the right temperature, and keep it there (95-105 F), you can feed in other biowastes - table scraps, lawn clippings, etc (plus a little extra water every now and then). Basically, it works like a liquidy compost pile (and yes, it needs to be stirred every now and then, just like a compost pile - most digesters use a motor powered stiring "paddle" - like an oversized paint mixer).
A septic tank has no insulation, and it generally isn't sealed well enough to keep the outside air out - plus it doesn't have the pressure relief and other mechanisms needed for proper gas delivery.
That isn't to say you couldn't build a methane digester for a home - but you couldn't just pump the water from the toilets into one, either - too much water in a digester is a bad thing - you would need to figure out a way to either separate the water from the waste (talk to a sanitation engineer for that one), or figure out a way to build a toilet that doesn't use water to flush (I would think some kind of "outhouse" style toilet could be made to do this well - but it wouldn't work in a home, obviously).
Your idea has merit - but it would have to be a system (both inside the house and outside) designed from the ground up - it probably wouldn't be something that could be retrofitted. Furthermore, you would have to keep a sharp eye on monitoring it - if it is something you really want to do, that wouldn't be a problem - but for most people, it would be too time consuming and technical to deal with (similar to a swimming pool, BTW, so maybe there is a whole new industry of service workers waiting there - methane digester servicing, anyone?)...
This theory does not say we will run out of oil, but that recoverable oil will take more and more energy to recover, until it reaches a point where it takes more energy to recover a barrel of oil, than would be provided by that barrel of recovered oil (basically thus becoming an energy sink).
The theory predicted that in 30 years (from roughly the 1970s), the oil that is recoverable without much in the way of input energy (that is, the oil recovered gives back more energy than was required to get it), that those days would be over in about 30 years (hence, the peak), and that world oil demand, coupled with falling recoverable oil reserves, would then lead to a gradual decline.
One could argue that what we are seeing in regards to the conflicts in the Middle East are one result of this (he who controls the last drops of oil will be in a very well off position both economically and politically in the future). If this is true, what is happenning now is only the tip of the iceberg - expect in the future even higher gas prices (like they have ever dropped - ha!), higher food prices, possible "plagues" of insects and disease in crops (since chemical controls made from petroleum sources will get more expensive, and either will be less used, or not used altogether), higher costs for electric, water, and sewage treatment...
Not too mention more wars, possibly world wars, as the countries which need, or perceive the need (like China) for this energy look to take it away from those (USA?) who control it...
Nearly all of western society is dependent with a capital "D" on oil - unless we change or augment it with a different energy source (hydrogen isn't it, unless we somehow could build fusion reactors to crack seawater - though I have posted many times how this might be able to be accomplished via solar energy, and have yet to be refuted though I beg for it - because my answer seems so simplistic as to be naive, thus likely having problems with it), we are likely to be screwed in another 20-30 years...
Word of caution: don't breath through your mouth unless you need the extra fiber...
They get hot - pretty damn hot, hot enough to kill a lot of "bad" things (just like any other form of decomposition, like a garden compost pile).
Methane Gas Recovery on the Farm
At the above link, you will find the following little tidbit:
Because manure digestion is anaerobic, most weed seeds and pathogens are killed during the process. Pathogens like E.coli, Salmonella, and Cryptosporidium can't survive the high temperature of heated digester. Fecal coliform bacteria numbers in the biosolids are only about one percent of those in fresh and stored manure, lowering the potential for this source of water pollution.
Forget about "mutated e. coli" - read a little before making posts demonstrating your ignorance...
2. Use "big words" and "science" to confuse people about cooling said beer.
3. ???^H^H^HGet grant of $20,000! Woohoo!!!
4. Profit, baby...
Why is it that these "mobs" of people can "come together", promoting violence, hatred, and fighting - amongst apparently (mostly) consenting adults (and disturbingly, children) - for what appear to be absolutely no reason at all! At best (in the cases of hooligans), it is over who's sports team is better!
Meanwhile, in the supposedly real world, we have people of all sorts (everywhere!), who are "arranging" their own sorts of "flash mobs" to kill each other over who knows what reason (is it oil? is it terrorism? is it entertainment?) - but no one is organizing "flash mobs" of protestors to stand against these attrocities against civilization!
We are living in a world of hate, anger, war and terror - yet I would bet that if you could poll each country's citizenry, likely 99% would say "yeah, I want peace, no fighting, just leave us alone, we'll leave you alone, and if you come visit, we can enjoy a brew down at the pub together"...
A sane society would each see the madmen for who they are, and get rid of them quickly and effectively, rather than letting them supposedly "lead" each other into conflicts that the majority don't really want.
You can't say to me that people really want war. You can't say to me that people really want body bags, sons and daughters missing limbs coming home, haunted looks in their eyes. You can't say to me people want to see each other blown up in a spray of bloody particles. Yet we continue to do what only a mad society would do.
Damnit! If only "The Day After Tommorow" wasn't a movie - we need a good cleaning to remind us of what is truely important (that, or just to show us, to our faces, what animals we really are - as if the current state of affairs can't do that)...