X-Message-Number: 2138 Date: Wed, 21 Apr 93 10:23:48 CDT From: Brian Wowk <> Subject: CRYONICS Ballast Comments Perry Metzger: > Here is a wacky idea -- possibly a bad one, but who knows. > Presumably, a mixture of water and cryoprotectants such as the > ones we use on patients would have a "knee" EXACTLY where we want > it -- at the glass transition point for the patients! Unfortunately (or perhaps fortunately) there is no phase change (crystalization) at the the glass transition point, and hence no energy absorption. As far as heat flow is concerned, the glass transition is a non-event Tim Freeman: > I wonder to what extent the ice will sublime from inside the buckets > and redeposit itself on the outside of the buckets? The vapor pressure of water is negligible at -130'C. I expect that the same goes for ethanol, which at this temperature is far below its boiling point. The biggest ice buildup problem is going to be from moist outside air that finds its way into the room. Most of this ice will deposit itself on the heat exchangers, which may have to be removed and defrosted from time to time. This is another reason to have two independent heat exchangers. --- Brian Wowk Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2138