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Chemistry / Re: l-carnitine
« on: 21/05/2004 12:08:01 »
It has an acetyl group attached to the molecule?
Angel
Angel
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quote:
Originally posted by tweener
Actually, it is both cold and hot at the same time. Temperature is a measure of the average velocity of the particles making up the material you are concerned with. In space, there is a very low particle density, relative to what we are used to on earth anyway, and the temperature is very high. But, because there are very few particles, the major heat transfer mechanism is radiation, not convection. You are right that as you move away from the sun the temperature gets colder, primarily because the sun (and the earth's magnetic field) is what is exciting the particles around the earth.
For a spacecraft, the temperature on the side facing the sun can be extremely hot and the side away from the sun gets very cold because all the heat radiates away and is not replaced or held by air. That's why the apollo spacecraft were made to spin - to keep the temperature even on all sides. More modern craft like the shuttle have better heat control (radiating panels in the doors to the cargo bay) and don't have to spin constantly.
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John - The Eternal Pessimist.