X-Message-Number: 8537
Date: Thu, 4 Sep 1997 12:42:17 -0400
From: yvan Bozzonetti <>
Subject: Corrosive LN2

In message #8515, G. Olschewski said:

(snip)...
> If you notice that samples deteriorate in direct 
>contact with LN2 over longer periods of time, then the reason for 
>this is, that most containers aren't pressure-sealed for the sake of
>simplicity. Thus oxygen out of the surrounding air with it's higher
>condensation point, diffuses into the LN2. This oxygen that is 
>resolved in the nitrogen is the actual reason why this "mixture" 
>may show corrosive properties. This effect could be completely 
>avoided by consequently working under oxygen-free conditions.
>
Well, that is not quite I found in my references, but OK I accept that
explanation. I conclude that, indeed, for PRACTICAL purposes LN2 is
corrosive, not in itself but because there are some impurities. Even with
the added cost of oxygen free storrage you don't get out the problem: Your
suppliers have not an oxygen free production-transportation line so the
product is contaminated from start. But why look at LN2 free from oxygen
when a simple plastic bag solve the problem? I think that debate is
splitting hairs.

The true question is why save LN2 if a cheaper, simpler, CO2 ice system can
work? the final objective would be to copy artemias salina eggs able to
live in suspended animation for many years in dried mud at hot temperature
(even boilling water). If the price to pay in uploading and not nanotech
repair, then I choose uploading.

Beyond the PP step there is a choice: Do we stand on LN2 technology for
poor preservation cases and try to go out with nanotech or are we moving to
dry ice then room temperature conservation for a mass technology (such cars
or computers) with recovery in uploading form?

Yvan Bozzonetti.

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