Engineering

Hi. Scientists are not fully sure; they have good suspicions the warming is caused by us. Very probable. What would be wrong with a lunatic idea of massively attempting to cover with cheap mylar mirror film the sunniest unused areas of the planet? Even roofs? Would that reflect a ~95% of their incident solar heat back to space? Tiny area in the global context, but... is there another action in plan? I have no clue on how calculations would have to be conducted to come up with a mirrored acreage to at least counteract the situation to get worse. Would you replace your car with a bicycle forever? Or just spend more energy in airconditioning your home ? …

Hi, It seems that new LED technologies will be past by laser technology in the display market. They even claim the end of plasma TV's. (due to better quality with lower production cost) news: http://www.theage.com.au/news/NATIONAL/Laser-TV-predicted-to-be-death-of-plasma/2006/10/10/1160246121576.html lasers: http://www.novalux.com/ Making a big investment in a new plasma screen could be a bad idea now. They claim to have a first commercial model end 2007.

i think this is the place to put it. i am looking in a dc (15v) relay. i want to have it so i press a butten and it opens for 5 or so seconts. i cant find how to do this so does any one know how i may go about doing this. thanks

Does anybody knows about a material (media or cloth) that allows the molecules of water to pass through but not the air (normal air). Thanks JP

can anyone help me how to build your own gyrocopter? anything any form any ideas:D

Hi there, How about using Air engine to be built up for normal day to day life use for e.g applications such as cars , bikes ,etc.. Thanks in advance...

The bad news of the city I live in is the price of housing is going through the roof. The good news is the city council seems to be interested in finding ways to rectify this I've seen information on several possibilities, here's what I know, I'd like some reliable info on these and other possiblities, I'll turn over the infor to the city council as I recieve it. Cord wood - good possiblity except here in redwood country, wood is profitable for other purposes Hay - Climate is too wet for it, decays when exposed to moisture Cobb (Earth) - Too unsafe in quakes??????? Too labor intensive? PaperCrete (Recycled Paper) - Water won't harm it, unknown o…

why is it not common with street performance cars to both turbo and super charge their engine? Also, what are peoples opinions of electric turbo's?

I suppose this is the best area for the question - Does anyone know how to construct a latch from 2 normally open switches? Not homework - just a brain teaser i can't solve!

My physics teacher, being the wonderful person she is, has assigned my class a project. The goal is to "build a car that is self-propelled." It basically means a propeller. I was wondering what the best design was. I figured 45 deg skew along the axis, and as large height- and length-wise as possible, but what about depth? Having the fans extend backwards? Anything else we should think of?

Ok, I've been drafted into the crab-lab here to help with some experiments involving magnetism, and we've decided we need a very large Helmholtz coil system. Since the cheapest one at the size we need (2 meter diameter, possibly bigger) costs as much as a new Lexus, we're going to build one, and have found plenty of resources on how to do so. However, I've hit a snag: wire temperature. We're going to have a *LOT* of wire in this thing (image 2 wheels 2 meters in diameter each with about 500 wire wraps around each), and field strength is proportionate to current strength. Now, I know the equation for power (P=RI^2), and I found the right equation to covert that i…

at the timer you have a hot wire going out to each valve, which then connects into a common wire. all the valves share the same common wire, and im assuming its nothing but a ground to complete the circuit. we just put in a second timer and because of how my yard is laid out and what wires i already ran it would be much easier for me if i could put the new valves on the new timer's hot wire, but on the old timer's common wire. im curious if there is any problem with connecting a valve to power through one timer, and grounding it through another timer. (didnt we used to have an electricity subforum?)

Opponents are always talking about nuclear waste disposal problems & the Nevada national disposal site is still not open . The French generate 80% of their electric power needs by nuclear energy . Does anybody know what they do with their waste ?

Once I left a beer in the freezer more than an hour for the quick chill. What I saw in the bottle was a delicate ice matrix. I popped the cap, and seeing also some liquid in the bottom, did the appropriate inversion. I drank maybe an ounce of strong malt liquor, and in less than a minute, felt the punch of the entire 12-oz. beer. WHOA, BETTY! I lucked out at the perfect moment where almost all the water was caught in the ice matrix leaving solubles like malt sugar and the other stuff, with the alcohol. I guess none of these things is incorporated into the crystals, not surprising, but you have to have the right freeze rate and, whatever, you tell me: this was a hug…

When temperatures outside are frigid we really appreciate the heat available from our internal combustion engines. It takes notably longer to heat the engine to where the thermostat opens excess to the radiator (not the heater core). How much more relatively efficient are we now? Figure output of horsepower, take a low cruising output of maybe 40 horsepower. That is like 30 kilowatts. I figure waste heat is of a similar magnitude, and that is a lot of heat, so it seems still wasteful. Is this correct, and, how do electric or hybrids deal with the notable loads of heating and AC cooling in summer? These will be proportionally higher loads to a smaller power plant.

Hello, can someone please explain to me why F1 engines are so good. even tho they are very low literage (which is capacity right?) i konw thye can rev up to 20krpm. so is that all an engine needds... to be able to rev ridiculously high? to be an awesome engine.

OK, so I have a neat but maybe improbable idea. A V12 engine with 4 turbochargers. One turbocharger for every three exhaust ports. And if possible a cold air intake on each turbocharger. The turbochargers would be smaller than normal ones, as to reduce blowback into the combustion chamber. I know the smaller turbos have special blowout valves so they dont blow up because of high pressure at really high speeds. So is there anything that I should know before i get to involved and start making designs. Or does anybody know if this has already been done.

Hey guys this probably sounds crazy, but why couldnt you use water in a diesel engine? ok first of all, i know they used to inject water WITH diesel/petrol to improve fuel efficiency with some engines, and racing cars. but the compression of a diesel lends itself to high compression temps right? (around 500C ?) so if you could inject a fine mist of water at this temperature wouldnt it expand to produce steam? or am i totally missing something? (probably the case) ive searched all over but the steam tables dont really make much sense to me as i say, it probably sounds (and is) a crazy idea. but id just like to know from the experts why it wouldn…

I wish to construct a very simple fuel cell. I wont spend a lot of time going into detail of my design but all I want to know is: -If i had a tank of hydrogen gas and a tank of oxygen gas and inside the tanks was a platinum electrode (the catalyst for converting h2 and o2 into its ions). By connecting the two electrodes together with a component in between, e.g. a light bulb. Will this produce an electrical current? -What will happen to the gases (oxygen and hydrogen)? Where will they go? because they are only joined by a wire they cant react together to form water The reason I ask this is because many fuel cells require an expensive, hard to find material whi…

the current mode of thinking suggests that the only use for turbines in automobiles is to power electric engines, but I have an idea I would like to see come to fruition. a true electric/gas turbine engine. turbine engines are horribly inefficient at low rpm, and electric engines are limited to relativly small run times with current battery technology. but why not combine both of these engine to run in tandem depending on how the car is driven? an electric motor could drive a car up to an effiecient running speed and then transfer power over to a turbine engine to run rather efficeintly. this idea would primarily be useful in semi trucks, trains, and ocean liners, bu…

alright so hydrogen cars seem like a good idea until you think about how explosive hydrogen is, what happens when there's an accident? and if the car did explode in a place like NYC or in a traffic jam, what woud happen to the other cars in the area? could you have a giant chain reaction?

Simple question: Shouldn't it be possible to use similar geometries that are used to make "stealth" aircraft nearly invisible to radar to make "stealth submarines" nearly invisible to sonar? The same principles should apply, right? Is this done? If not, why? My only guess is that the decrease in hydrodynamical performance would just be too great to justify it.

how does a cars speedometer work? my brother suggested some kind of friction based device, where the faster one piece is turning the more the piece touching it gets raised. i was very disappointed to find that howstuffworks didnt have an entry for this one : (

How was cryogenics found? Any answers please... Thanks..

Do you guys think that chemical engineers will be as important as they are today 20 years from now? Why or why not