[ExI] Help with freezing phenomenon

[Jeff Davis]

Recently, there has been discussion in the CI Google group about the
CAS (cells alive system) freezing system being distributed
commercially by a Japanese company, ABI. Originally intended for food
preservation, the method claims much higher quality preservation,
approaching "fresh".

It was invented in 1996, publicized in an article in Forbes in 2008.
http://www.forbes.com/forbes/2008/0602/076.html, and came to my
attention last year.   I googled it, read about it, and sent an
inquiry to the company.  As a cryonicist my interest is obvious, so I
payed particular attention to the organ preservation angle.  Then this
week another article on a site called Singularity Hub.
http://singularityhub.com/2011/01/23/food-freezing-technology-preserves-human-teeth-organs-next/
-- features the technology once again.  This time tooth freezing with
a transplant success of 87 percent.

A very short (and potentially very 'dirty') description of the
process: a valuable bluefin tuna is caught and put in the CAS freezer
on the boat.  The cooling airflow temp is say -10 degrees C.  (Higher
than the -40C typical of flash freezing.) Somewhere in the vicinity of
the cooling chamber (probably around it) is a mechanism that produces
a varying magnetic/electric field. The influence of this "field"
during the cooling process is claimed to delay the onset of freezing.
This may sometimes be phrased as "depressing the freezing point".
Then, when the entire tuna is at a uniform (or maybe just close)
temperature below the "undepressed" freezing point, the field is
turned off, and the entire tuna 'flashes' solid.  There are guesses --
first generation?; sure to be wrong?) --that the ice is in the form of
small granules that substantially reduces freeze damage.

I need more damn details, or I'm gonna embarrass myself.

That should get you started.  Now here's my question.

The thermal conductivity of water is 0.58 kW/mK.  Of ice, 1.12 kW/mK
(increases with decrease in temp.).   Does this mean that given
similar geometry, water will cool more slowly than ice?  Does this
mean that the conventional flash-frozen tuna will begin to cool
***more quickly*** as the outer layers freeze solid, and then freeze
ever more quickly as the frozen 'shell' thickens?   Does this mean
that the CAS process ***SLOWS*** the flow of heat out of the frozen
tuna, precisely because it maintains the tuna in a "liquid" -- ie not
solidified state -- as it is cooled.

I ask because I was expecting the reverse.  Somehow I got the notion
that the outer shell of ice (conventional freezing) would slow the
cooling rate, compared to the "shell" of fluid tissue kept unfrozen
until the end point of the CAS process.


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Water isn't tissue.  And convection, ...what about convection?!

Make believe there is no such thing as convection.

 I know, I know.


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Cryopreservation of periodontal ligament cells with magnetic field for
tooth banking

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WD5-5033XY2-1&_user=10&_coverDate=08/31/2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4873b90b166ee18578b31651f180d459&searchtype=a


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Best, jeff davis

          "Everything's hard till you know how to do it."
                                                Ray Charles