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Everything posted by SH3RL0CK

  1. Sure, there are ways to generate energy which are conceivably better than corn to ethanol. But every solution to our thirst for energy, green or not, has problems. I do not believe that we will ever be burning ethanol for the production of electricity, but for use in automobiles it makes great sense to me for the short-to medium term. Long-term, nuclear fusion to generate electricity and hydrogen fuel for travel would be perfect, but isn't possible yet. Since I think it will be another 50+ years before we have the technology for nuclear fusion power conversion to electricity we do need to be creatively thinking about how to generate the energy necessary until then. We haven't solved (and probably won't) the nuclear waste issue with fission. Solar cells consume awesome amounts of pollution to create and is dependant on abundant sunshine anyway, windmills kill birds and Ted Kennedy's view while sailing , hydroelectric is pretty much tapped out in the lower 48 states of the US, ocean driven energy is still being developed... True change may be necessary, but it is going to take a while to get there.
  2. After some research, other posters were correct, the production of ethanol does indeed reduce the nutritional value of the corn as animal feedstock (which is where a very large portion of the corn grown in the US goes). http://www.ddgs.umn.edu/overview.htm from the article: "yielding a DE [dietary equivalent] value that is approximately 91% of that found in corn. " But the loss can be minimized to only 9% with proper treatment of the distillers grains, so I still do not buy the argument that we cannot generate both food and fuel from the corn, nor do I see why rationally, biofuels can be blamed for the price increase of grain on the international markets. Perhaps inefficient use and conversions of the distillers grain? If so, surely this could be overcome? Also, regarding the cost of a gallon of ethanol, see: http://www.energyfuturecoalition.org/biofuels/fact_ethanol.htm#4 from the article: "The two largest variables in the cost of ethanol are the cost of corn and the cost of natural gas or other sources of heat needed to process the mixture. When corn costs $2 a bushel, it costs between $1 and $1.20 to make a gallon of ethanol. Because ethanol has only two-thirds the energy content of gasoline, that’s equivalent to $1.50-$1.80 per gallon of gasoline (wholesale), or $50-$60 per barrel of oil. At that price of corn, ethanol is competitive with gasoline with the current subsidy for gasoline blenders when oil costs $30 a barrel or more. It is economically competitive with gasoline without a subsidy when oil costs $50 a barrel or more." see also: http://devafdc.nrel.gov/pdfs/4898.pdf Granted the raw materials cost of both corn and natural gas have increased above the above values. However, it seems to me that with grain costs roughly doubling at $4.28 a bushel, and natural gas costs not doubling either since 2006, and other costs (labor, equipment, etc) remaining the same as in 2006, you could safely assume ethanol is still cost competitive, without a subsidy, to gasoline with oil at $120 a barrel. I am still convinced we should be converting as much corn into ethanol as we can. It would greatly reduce the greenhouse gas emissions, reduce other pollution effects, and keep money in the US (and away from the dictators in the middle east), along with other beneficial side effects.
  3. I'm not sure but this might be more art than science. I would suggest you experiment. You could try a few things (on other glass samples with varying sizes and types of wires) to see what works and what doesn't.
  4. You have to melt the glass around the wire.
  5. Ethanol production from corn uses only the inedible parts of the corn kernel. The remainder, called distillers grain, has as much food value as pure corn and is fed to livestock as is/was corn. The rise of food prices is more of a reflection of the cost to ship the food than because of ethanol production. http://www.ethanol.org
  6. A very big part of the increase of the cost of food at the grocery store is the fuel used to make and ship it...its much more significant than the price of the food itself. It would seem to me that the production of biofuels might possibly reduce the price of food by decreasing the cost of fuel. I base this on the fact that ethanol costs about $1.80 per gallon to produce (without government subsidies I should add), and this could very well decrease due to economies of scale savings from increased production. So reducing the fuel costs from $3.60 to $1.80 reduces the price of the fuel (the major reason for food price increases) in half. A 50% reduction in fuel costs is, IMO, quite significant.
  7. I have always thought the problem was not in the food supply but rather the distribution of the food. Right now there is a surplus of food, globally, with the potential to grow even more (there is a significant amount of arableland in the USA and in other countries which lies fallow). In some locations, sadly, there are food shortages. Here, the price of food is too high for the people. A great case example of this would be Korea. Prior to the end of WWII, the entire country was essentially in the same place. But today, N. Korea starves while S. Korea is rich. Why? Nevertheless, as long as there are food surpluses, I don't see how biofuels are a bad thing. Though they might indeed make the situation worse by raising prices, the root cause is not, and would not be biofuels (until such time as there are actual food shortages).
  8. Look at it from the voltage standpoint. What is the voltage drop across the switch when it is closed? Will it be a large voltage or a small voltage? Take this voltage across the bulb C and determine the current which will flow through bulb C by Ohms law, I = V/R. This should give you the answer you are looking for.
  9. It is easy to get expelled from somewhere, just act inappropriately. Hey, how much is the entrance fee? Maybe I could come out ahead here I might be willing to take that bet, but I need to put limitations on the behavior of the group (i.e. no inappropriate behavior)...and I suppose we would also want the questions to be probing of the flaws in this musuem as well. I don't know how we could verify the actions of anyone there. It would be a he said, she said situation if they did get expelled, and if they didn't I suppose one could argue they weren't critical enough.
  10. I am not at all convinced that biofuels must consume more energy than they generate. It is my belief that this is misinformation from the oil companies and that every environmentalist who agrees with this information are deceived and/or tools for the oil corporations. See for example: http://www.ethanol.org/index.php?id=81&parentid=25#MISCONCEPTIONS http://www.ethanol.org/pdf/contentmgmt/Issue_Brief_Ethanols_Energy_Balance.pdf from the article: Additionally, the use of corn for ethanol feedstock is especially advantageous. After the ethanol is removed from the corn, the remainder contains as much food value as before the ethanol was removed. What could be better than two valuable products (food and fuel) for the price of one? see: http://www.ethanol.org/index.php?id=38&parentid=8#Distillers%20Grain
  11. My experience in the United States is very similar to Josh (aka 7he3ngineer). 5+ hours of work on a on a single assignment, and 24h+ on a design project isn't at all unusual. That said, you do have a week or so for the assignments, and the whole semester for the design project. Just don't wait until the last minute on anything. It is possible to do these in smaller time increments, in fact when I was in school, I would usually take a break every 1-2 hours. It is all doable if you want it. The questions you need to ask yourself is do you want to be an engineer? Why? and How badly? If you don't know this is what you want to do, or are not sure what you want, perhaps a business degree would be more appropriate. With a business degree you can work in any industry that interests you (albeit on the financial side).
  12. I think the hardest part is sticking with it, even while getting C's after studying all night and watching your friends in other (easier) majors getting A's after partying all night. Its really hard then to stay committed to getting this degree, when you can drop the goal and do as they do. It helps to keep the long term perspective in mind, after college there isn't as much demand, or pay, for a basketweaver as there is for an engineer.
  13. Heh, its funny to think this will hinder the illicit drug manufacturers at all. As you say, you can buy similar equipment at your local hardware store (safety and cleanliness really aren't a concern here). Or if you really needed something, you could just get them in a neighboring state or Mexico and carry them in as well. Or steal them from the local school. Or just lie and pay to get the permit. This will do absolutely nothing to hinder drugs, but just be a PITA for legit users of this type of equipment. But then, very few politicians (or journalists for that matter) have any common sense. Unfortunately for us, politicians are the ones who make the laws, usually because journalists push an issue to get their viewership ratings up.
  14. Since it does interact with gravity (dark matter has been shown to create gravitational lensing), presumably it would get sucked into black holes as does the matter we know about. If we actually knew what dark matter was, we could probably answer your question better.
  15. My experience is that I graduated from a major college in the USA about 15 years ago, now I am gainfully employed as an electrical engineer. I do not beleive it is ever easy to get an engineering degree, you will have to do a considerable amount of hard work. That you aren't great at math will not help you either, but if you really want to be an engineer I would not let that stop you, you might want to consider taking extra formal math classes to catch up on your math skills. Many people drop out in the first year or two because it is so difficult. In my experience it did get easier after the first two years, but you really have to be committed to it to graduate. As far as your chances, that really depends on how hard you work, how efficiently you work, and how committed you are to this goal.
  16. Yet again, this is not a conflict if only a small portion (but all of it that Noah knew about) of the earth flooded. Its also not a conflict if the story is meant to be an allegory. There are very many ways to interpret the Bible, different people hold differing views on the flood story, on evolution, on creation, etc. Some religious people believe in a 6 day (= 144 hours) creation and others believe in a 6 "days = unspecified period of time" = about 14 billion year creation. Who am I to say which is the correct interpretation (although I agree with the interpretation which best matches science as we know it today). I once read that at one time science believed the universe was only 6,000 years old (before nuclear science was known somebody calculated that the sun, as a chemical fire, could be no older than this). This was the basis of the 6,000 year old creation story, someone else tried to fit the Bible to Science . For some interesting perspective on this, you could go to: http://www.reasons.org/resources/apologetics/flood.shtml http://www.reasons.org/resources/apologetics/index.shtml#young_earth_vs_old_earth Science and faith simply do not address the same questions in my opinion, it is silly to suggest that they do.
  17. I've heard that arguement before. And the arguement about the ark not being large enough for specimens of all the animals in the world. But then you have to define "world" in the sense of someone writing if thousands of years ago. Is all the land Noah and his culture knew about, the world as he knew it? Of course. If so, then the flood only needed only to cover perhaps a small island to completely flood Noah's world. As such, there would have been plenty of space in the ark, and he could have easily had specimens of each creature known in his world. As an aside comment, I don't view any valid debate as science against the bible and your inference to this confuses me. They each have different purposes, and where they interlap they agree or at least can be interpreted in a manner which does not disagree. The Bible wasn't meant to answer every science questions and likewise science cannot answer every spiritual question.
  18. Also, I think you should try to talk with others working in the field who are not professors to give you an idea of career possibilities apart from teaching at the University. I don't know how you would meet these individuals, but if you work at it you should be able to find at least a few contact and some career advice. Maybe you could get a summer internship? Even if it were an unpaid internship, I think it would be time well spent.
  19. OK, I can see how this would work. But wouldn't the conclusion eventually end up the same? There are only so many resources in a given solar system, given enough time wouldn't these civilizations be force to leave a solar system because the resources there are exhausted or because the civilization has outgrown that particular solar system? Therefore, they would still reach us out of necessity. And if e.t. was mining the moon for iron ore, I think we would notice. Of course, how much time it would take to do this could be longer than the present age of the universe depending factors such as the civilization growth rate, size of the solar system, etc. I have no idea how to calculate this critical time (to consume the resources of a solar system), but since we are talking exponential growth of the civilization, I imagine the argument is still valid. Or is the resources in a given solar system THAT much greater than on a single planet?
  20. http://en.wikipedia.org/wiki/Flowers_for_algernon
  21. I would think you can readily build or buy what you need from a place such as http://www.omega.com, I suggest you take a look here (or similar company) first. Why can you not use the temperature sensors the company provides? I can envision at least two possibilities: 1) the sensor element (such as the thermocouple or RTD) doesn't work below 70. 2) The display doesn't work when the signal is indicating a temperature below 70. Of the two, the second seems most likely to me. You should try to find out what type of sensing element they are using. If they are using an RTD, it may be possible to "fool" the device by adding a resistance in series (or parallel) with the sensor. Of course then you would need a correlation table so that when the display is reading 100 degrees you will know the actual temperature is 10 degrees.
  22. Actually all you need is two different materials, one significantly more conductive than the other. I have heard of a motor being built out of only Aluminum and Iron. The Iron is the insulator. I'm sure there is quite a bit of energy loss in this type of motor, but I don't see why it wouldn't work. As there are (relatively) conductive plastics, in theory you could make a motor entirely out plastic as well (though I think this would be very inefficient as the magnetic field would be quite weak).
  23. I fail to understand why anyone would buy one for US$5000 when they could buy either a bicycle or golf cart (either of which would be much more useful, IMO, than the Segway) for US$500 or less. For what it is worth, you can buy a decent used car for US$5000.
  24. One thing that hasn't been noted here yet is cost. Incandescent bulbs are the cheapest to buy, followed by fluorescent, and then the most expensive is LED lighting (I haven't even seen these for sale in Home Depot yet). Fluorescents have gotten cheaper (especially the compact versions that screw into the normal "incandescent" light bulb fittings), but are still more expensive initially than incandescent. However, they make up the cost difference due to the electricity saved and because they typically last so much longer. I don't think it would be fair to compare LEDs since they aren't in common use yet and as I understand it, there are factors that can affect their longevity.
  25. Why can I not use "Impedance" as part of the explaination? But I like a challenge. Rather than using equations (which will eventually lead to this verbotten word), think of it intuitively. Think of the ferrite as an inductor. An inductor will build a magnetic field in response to the current flowing through. When the current changes, the magnetic field must also change in this inductor. Now if the inductor were designed to be inefficient (as a ferrite is) there will be energy lost when this magnetic field changes, which will results in less current flow. At low frequencies, the field does not change much and there is little energy lost. At high frequencies, there is more energy lost because the field changes often. Therefore with much energy lost, the current is suppressed. Its quite a bit more complicated than this, but this is the best I can do without going into a great deal of mathematical equations.
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