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Re: F-word: second thoughts
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Bernhard Rupp wrote:
> As cryo-pioneer Hakon Hope has already pointed out over a decade ago,
> you do not want to FREEZE a crystal. Freezing technically implies
> the formation of ice, and that is exactly what you seek to avoid.
> So, keep on cryo-cooling, quenching, shock cooling whatever you like.
But no more flash-freezing, right?
Cryo-electronmicroscopists like to image samples in "vitreous ice".
Would you consider that a contradiction in terms? are they really
using glassy water?
Having sent this, I was actually motivated to look up the words
in the McGraw-Hill Dictionary of Scientific and Technical terms:
FREEZE: to solidify a liquid by removal of heat
ICE: The dense substance formed by freezing water to the solid state,
has a melting point of 32 F or 0 C, and commonly occurs in the form
of hexagonal crystals.
(so this could include hexagonal ice, cubic ice, and glassy ice? As
you warm up vitreous ice it forms cubic ice then hex ice then
melts at 0C?)
1. A substance that has a definite volume and shape and resists
forces that tend to alter its volume or shape.
2. A crystalline material, that is . . .
If we take the first definition of solid, then cryocooled crystals
and their surrounding mother liquor are solid, and since they got
to be that way by removal of heat they are frozen.
If we take the second definition, Hats off to Hope, and never let
any of my crystals be frozen!
Only question is- why am I wasting my time and yours on this?
Hope no one on my NIH study section reads this.
Edward A. Berry, MailStop 3-250
Lawrence Berkeley National Laboratory
1 Cyclotron Road, Berkeley, CA 94720
Jfax +1-530-323-9836 (you send fax, I receive email)
- From: "Bernhard Rupp" <firstname.lastname@example.org>