On 02/07/12 11:12, Dirk Kostrewa wrote:
Dear Jürgen,
Am 07.02.12 16:58, schrieb Bosch, Juergen:
<snip>
Then one last remark, LN2 versus cryo-stream freeze. Dipping in LN2
leads to a quicker freeze of your material.
</snip>
Are you sure? There was a publication by Warkentin et al. [1] about a
cold gas layer above liquid nitrogen that reduces the expected cooling
rate a lot!
My very personal experience is, that cryo-cooling in the N2-stream
worked better for me than in LN2 in a variety of projects - but the
reason could just be me ;-)
Yes, Warkentin, et al found the cold gas layer affects cooling rate -
but they were able to overcome it by blowing air across the surface.
Your point is taken that complications such as this affect the cooling
rate much more than a simple liquid vs. stream choice.
--
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All Things Serve the Beam
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David J. Schuller
modern man in a post-modern world
MacCHESS, Cornell University
[email protected]
