Actually, xenon is my second choice. I had to switch to it when I wasn't able to buy radon from this group of Libyan nationals I used to know.

i only fill my tires with 100% pure oxygen. it helps my car with a much cleaner, fuller combustion.

Man .. yeah that helium is so powerful.

Did yall see the mythbusters episode where they tried to float a kid with balloons? I think that they had several thousand of them, it took up a large part of the hangar that they use all the time, but they had just enough lifting power to keep the kid off the ground, but not enough for it to take off.

When I was doing my balloon project, I think our total payload was darn light, Id like to say under 2kg and we used half an industrial tank of helium each time we filled a balloon up.

BTW I know you werent serious sts, I was just saying that the lifting power of helium is surprising low. NASA uses hydrogen for their stratospheric ballons, but yeah, we couldnt get approved for that, there was so much red tape as it was, attempting to send the balloon to altitude.

but seriously, i'm filling my tires with CH4

that way when I tell someone that I'm just fartin around town on a saturday afternoon.... I won't have to be facetious

if you ate the gyro and hummus i had for dinner last night, you wouldn't be facetious either

quote:

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but seriously, i'm filling my tires with CH4

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When I was kid, a lot of farmers used butane (and later, propane) in their tractors and pickups.

It was pretty common for guys to air up flats, especially on cotton trailers, with a hose from their butane tank. This gave rise to two problems.

1)You think 78% N, 21% O2 expands when hot? Try C4H10.

2)Tire guys get really pissy when you forget to tell them that the flat you brought in contains an explosive mixture.

Randy03,

Air is ideal, for the most part. Z=0.98, IIRC.

But what you said is true.

And if you are worried about the "moisture" in your tire from the air compressor, put a desicator inline on the outlet of the compressor. Should get the dew point down to about -40F. At that level, there is little to no discernable amount of water.

~egon

Well you know its been a long time since Thermo, all I had to take in school was ENGR212, I dont think that ELENs even need to take that anymore, which is kind of a shame, but I also understand that with as wide as ELEN is as a field, another ELEN specific course is helpful, particularly when you are never going to do any thermo as an ELEN anyhow.

However, being familiar with some thermo really helps on the FE, too bad that almost no ELENs take the FE. I still think that anyone who wants to work in a position that is called "engineer" should be forced to do state licensing, like lawyers or doctors. It would both protect the public and protect the field a win-win.