X-Message-Number: 33234
From: "Jens Rabis" <>
Subject: AW: CryoNet #33232
Date: Sat, 15 Jan 2011 13:35:10 +0100

Hi cryonauts,


Keyword:  Freezing point depression (misunderstood word because you think up
to, but that does down in temperature)
http://en.wikipedia.org/wiki/Freezing-point_depression

The school was long ago. Simply put, if you want to cool a large body
quickly, you need something that is colder than ice / ice water. However, it
should be liquid because liquids dissipate heat faster. Better is cold salt
water. I've also read highly concentrated (what?) of salt water with
alcohol. This one creates as -20 degrees Celsius. Please ask specialists.

****

Stichwort: Gefrierpunktserniedrigung (missverstandliches Wort weil man denkt
an rauf, aber das bedeutet runter in der Temperatur)
http://de.wikipedia.org/wiki/Gefrierpunktserniedrigung

Die Schule ist lange her. Einfach gesagt, wenn man einen groBes Korper
schnell abkuhlen will, braucht man etwas was kalter ist als Eis / Eiswasser.
Es sollte aber flussig sein, weil Flussigkeiten schneller Warme abfuhren.
Besser ist kuhles Salzwasser, ich habe auch gelesen hochkonzentriertes (wie
hoch?) Salzwasser mit Alkohol. Damit schafft man unter  -20 Grad Celsius.
Bitte fragt Spezialisten. 

Best greetings
Jens Rabis
Germany-Berlin
" The time is with us, we can ... more!  "



Message #33232
From: "Eisab" <>
References: <>
Subject:   latent heat of fusion
Date: Fri, 14 Jan 2011 21:34:58 -0500

"Despite the control applied to the cooling of cells, most of the water
present will freeze at approximately -2 C to -5 C. The change in state from
liquid to crystalline form results in the release of energy in the form of
heat; this is known as the latent heat of fusion. Warming of the sample
occurs until the equilibrium freezing point is reached, at which temperature
ice continues to form. To minimize the detrimental effects of this
phenomenon, undercooling must be minimized by artificially inducing the
formation of ice. This can be accomplished by seeding the suspension with
ice or some other nucleating agent, or by rapidly dropping the temperature
of the external environment to encourage ice crystal formation."

http://www.nalgenelabware.com/techdata/Technical/cryo.pdf

I  wonder if the latent heat of fusion is a big problem in cryonics.

Basie 

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