X-Message-Number: 18924 Date: Sun, 14 Apr 2002 12:32:45 -0400 From: "Henry R. Hirsch" <> Subject: Volume heating and cooling: Adiabatic demagnetization and In cryonics, the problem with most heating and cooling techniques is that the energy has to be transmitted to or from a relatively large volume of tissue through a relatively small surface area. The rate of heating or cooling is therefore relatively slow. Microwave heating gets around this problem because the heat is produced throughout the tisssue volume. Adiabatic demagnetization with appropriate magnetic fluids can, in principle, offer the same advantage with respect to cooling. The tissue would be perfused with a magnetized fluid. Upon demagnetization it would cool due to entropic effects. This is essentially the way liquid helium is brought to temperatures near absolute zero. If I were young enough, strong enough, and rich enough, I would follow up on this idea myself. Since none of these apply, I offer the idea to the cryonics community at large. I have a lot of references that would be useful. If you want them, send me an e-mail. I won't reply right away because I am home recovering from surgery. However, when I can get back to my office, I'll send them along. Please provide a postal address and phone number as well as an e-mail address. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=18924