X-Message-Number: 4795 Date: 20 Aug 95 11:35:43 EDT From: yvan Bozzonetti <> Subject: Blue Blood Bottom Some time ago, Mr. Garret Smyth said in message 4776 : >The cracking in large tissue samples is usually attributed to mechanical strain >because of a temperature gradient. One part of the patient has contracted more >than the rest and stress is built up. Also, it is thought to occur only at >fairly low temperatures when expansion has finished. There has been a lot of >discussion of methods to overcome the problem - the main topics being rates of >cooling and also a cheap and reliable method of storage at the relatively hot >temperature of -130(ish) degrees c. There is how I see the things: Cracks come into play when strain exceeds mechanical capacity of a solid. In our case I think when all liquid water goes solid at near -130 degrees C, stifness get too large and any small mechanical constrain added to thr corpse produces cracks. handling could do the same, so that slow cooling is not sufficient ( I have written before about the need for slow cooling). Water expansion in ice form is the main agent in building in the first place the basic strain, when temperature get sufficiently cold, salts ladded water turns to glass, more than half a body mass at liquid nitrogen temperature is glass, not ice. This glassy state seems very britle and it would be wise not to load it with ice expansion generated strain. That was the essence of my proposal.I think we need to reduce strains even if they don't translate into cracks because they could shatter a whole body at any time for any reason : thermal effect, recrystalization (glass turning ice), handling... Cryonics patients would have a better prospect to get back comming from the blue. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4795