h a l f b a k e r yCompound disinterest.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
"The form of ice that is created when water is cooled at atmospheric pressure, 'Ice I',has a higher unit volume than the liquid water. As a result, increasing the pressure actually causes ice to melt rather then water to solidify. That is, up to a pressure of about 2000 atm. Above this pressure, other,
more dense forms of solid water (Ice II, Ice III, Ice V, Ice VI, and Ice VII) can form." (link1)
These ice forms are denser than water. (link2)
So, perhaps they would not damage the cells like ordinary ice does.
For instance, Ice III is formed by cooling water down to 250 K at 300 MPa [Wikipedia:Ice III]. The pressure would occur naturally in the sea, 30 kilometers below the sea level.
"Ice III ... has a density of 1.16 g cm-3 (at 350 MPa where water density = 1.13 g cm-3)." (link about Ice III)
It's a contraction by only 2.65%, versus the usual expansion by 8.33% upon freezing.
Freezing Water at 100 degrees C
http://www.newton.d...hem00/chem00298.htm
[Inyuki, Sep 06 2012]
Ice phases
http://www.lsbu.ac.uk/water/ice.html
[Inyuki, Sep 06 2012]
File:Density of ice and water (en).svg
http://upload.wikim...iagram_of_water.svg
[Inyuki, Sep 06 2012]
Preezing.
Preezing
[2 fries shy of a happy meal, Sep 06 2012]
Nitrogen boiling point at 3000 bars
http://www.wolframa...+point+at+3000+bars
=> cooling with nitrogen would be impossible at this pressure. [Inyuki, Sep 06 2012]
Density Changes
http://www.lsbu.ac....ater/phase.html#den
[Inyuki, Sep 06 2012]
Ice III
http://www.lsbu.ac.uk/water/ice_iii.html
[Inyuki, Sep 06 2012]
high pressure microscope
http://www.ncbi.nlm...gov/pubmed/15529757
Microscopy under pressures up to 300 MPa. [Inyuki, Sep 06 2012]
High pressure freezing and thawing of foods: a review
http://www.scienced...i/S0140700701000305
It seems, these techniques had been used in recent 20 years, but for a different purpose. Cryogenecists really didn't think of it?.. [Inyuki, Sep 06 2012]
Suspended Animation
Suspended_20Animation
I posted this Idea back in 2001 [Vernon, Sep 06 2012]
High Pressure Cryonics
http://www.benbest....onics/pressure.html
"A German cryonicist, who has training in physical chemistry, has suggested that high pressure may be the best means of eliminating freezing damage in cryonics." [ Halfbaked? ] [Inyuki, Sep 07 2012]
Magnetic Resonance Freezing (for foods)
http://onlinelibrar...4302325.ch5/summary
"STEP1: Food undergoes continuous magnetic wave vibrations, which impede crystallisation. STEP2: After a suitable product-specific period of time the magnetic fields are abruptly removed, with uniform flash freezing of the entire food volume, avoiding cracks and related damages." [Inyuki, Sep 07 2012]
The Ice I - line...- just go down the slope..
https://en.wikipedi...I_phase_diagram.svg
[Inyuki, Oct 29 2018]
Instant freeze water
https://youtu.be/RMzio5sLN48
Shows very cold water freezing quickly when bumped or opened (lowering pressure) [caspian, Oct 30 2018]
High pressure freezing and thawing
http://www.ref-wiki...ng-and-thawing.html
Found a description of pressure shift freezing, it's similar to what I was thinking of [caspian, Oct 30 2018]
Ultra-fast freezing at high pressure
https://www.leica-m...EAAYASAAEgKg8vD_BwE
[MaxwellBuchanan, Oct 30 2018]
Water phase diagram says we could stay solid at high temperatures...
https://en.wikipedi...iagram_of_water.svg
"Why can't you raise the pressure as you bleed off heat?" [Voice] -- cause at some point that pressure and temperature may lead to unwanted chemical changes in the body... [Inyuki, Sep 01 2019]
[link]
|
| |
I'm not a biologist, but it's possible that subjecting human tissue to pressures above 2000atm might damage it in other ways. |
|
| |
Perhaps there is no conclusive answer to this question without experimentation... unless there is something inside the cells, like organelles, that would be irrecoverably disrupted by the crystallization anyway. However, there was some success in preserving small organs even under atmospheric pressure. So, I guess it's an open question... |
|
| |
[8th of 7]'s anno to my version, [link] of this idea; |
|
| |
The problem is the size of a tomato (or rather its surface area to volume ratio). Fruit such as raspberrries can be frozen effectively using liquid Nitrogen; but with larger items, the outside freezes before the inside (in extreme cold) and you get bursting of the cell walls. Chilling the item to + 0.1 C, then drenching in LN2, sort-of works but is far from perfect - because on defrosting, the outside melts first .... barometric pressure has almost no effect on the thermodynamics. |
|
| |
For cryopreservation of vegetable material like soft fruit, rapid cooling resulting in minimal ice crystal sizes is the Holy Grail. The larger the item, the harder it is to cool the whole mass very fast.// |
|
| |
[2 fries shy of a happy meal], Wow, and you thought of something very similar in 2009. [+ for you] |
|
| |
I guess the bursting cell walls occur because of the different densities of unfrozen and frozen cells. So, the question boils down to: whether water density increase is better than its decrease. |
|
| |
(Ideally, we would want to find such pressure, where density of frozen water coincides with the density of unfrozen water, but according to the diagrams in link [Density Changes], there is no such point.) |
|
| |
Pretty sure that cryogenecists have thought about
adjusting even as radical a variable as pressure to change
ice phases during freezing for cryonics. |
|
| |
Perhaps it is not practical to achieve that pressures at this time, however, I'm convinced that in the future we will not rely so much on the temperature, but on pressure. |
|
| |
Pressure propagates at the speed of sound, but temperature transduces slowly. According to the water phase diagram, apply pressure of 1250 MPa to human body of natural temperature of 36.8'C (98.24'F), and it will uniformly convert into ice. |
|
| |
/30 kilometers below the sea level/
where is this? |
|
| |
/Pretty sure that cryogenecists have thought/
nah. theys ignorant. |
|
| |
/apply pressure of 1250 MPa to human body of natural temperature of 36.8'C (98.24'F), and it will uniformly convert into ice./
what? more pressure raises freezing point of water? I thought it was the other way around - increased pressure makes water volume increase on freezing more difficult, and so high pressure lowers freezing point. |
|
| |
//apply pressure of 1250 MPa to human body of
natural temperature of 36.8'C (98.24'F), and it will
uniformly convert into ice.// |
|
| |
That is a very, very elegant idea. |
|
| |
Would the body have to be stored under that pressure, or would it shatter if it was removed to be placed into permanent cold storage? |
|
| |
There's only one way to find out for certain
… |
|
| |
//apply pressure of 1250 MPa to human body of natural temperature of 36.8'C (98.24'F), and it will uniformly convert into ice.// |
|
| |
Interesting thought, but after doing some calculations, I don't think it would actually work. |
|
| |
I assume you're talking about converting to ice VI. There will be heating during the phase change. I assume if the temperature gets too hot (scalding temperature maybe) it could break chemical bonds that we don't want to be broken. The temperature ought to increase uniformly assuming the pressure increase is reasonably rapid, so if we can pre-cool the subject, use pressure to rapidly and uniformly solidify the water, then cool the ice for storage, that seems reasonable. |
|
| |
Unfortunately the triple points chart from the "Density Changes" link appears to indicate that the temperature change would be much too large. I think these charts indicate that the phase change between liquid and ice VI can happen anywhere between 0.16C and 81.85C depending on the pressure. I'm not sure what deltaH and deltaS are exactly, but based on the units, it looks like 1000*deltaH/deltaS would tell me roughly how much the temperature would change if the phase change happens because of pressure alone. For the liquid to ice VI transition, 1000*deltaH/deltaS is between 273K and 353K. So even if you pre-cooled your subject to 0.16C, using pressure increase to freeze it would make the temperature too high for ice VI to exist, and much too hot to avoid other damage. If you increase the pressure and reduce the temperature all the way to -21.9C, then transition from water through ice III, V, VI, and VII, your final temperature would be slightly lower but the dH and dS look similar for these transitions as well, so I suspect you'll still be way over 200C. |
|
| |
// Assembly is the reverse of disassembly // |
|
| |
Oh, well, good, that's that part of the problem
solved, then … |
|
| |
Another question is whether high-temperature
ices will preserve biology in the same way that low
temperatures do. |
|
| |
On the one hand, they should: they would
immobilize everything and prevent bacteria and
proteases and whatnot from screwing up your
cells. |
|
| |
On the other hand, everything's still warm, so
maybe chemistry would just carry on and you'd
just rust to death. |
|
| |
// if there are disolved gases // |
|
| |
Well, if there's no oxygen, nitrogen or CO2
then the whole preservation thing is moot,
'cos you'd be dead. |
|
| |
"Ice III ... has a density of 1.16 g cm-3 (at 350 MPa where water density = 1.13 g cm-3)." (link about Ice III)
It's a contraction by only 2.65%, versus the usual expansion by 8.33% upon freezing. |
|
| |
[scad mientist], since according to your calculation, transition to Ice VI because of pressure alone seem impracticable, the transition from liquid to Ice III occuring not only because of pressure, but from combination of temperature and pressure, as suggested in the original idea, seems to be the second best option. |
|
| |
Seems like this idea had been around for 20 years, in the field of food preservation (see link: High pressure freezing and thawing of foods: a review, 2002.) |
|
| |
[Vernon], [+]. I really like your lengthy depiction. I wish it really worked as you depicted. |
|
| |
Why can't you raise the pressure as you bleed off
heat? |
|
| |
The link on high-pressure freezing of food says " this
process permits the significant preservation of the
microstructure of biological substances" - which is
very interesting. |
|
| |
Suggest substituting water with whiskey. Might not work but what a way to go? |
|
| |
Alcohol's euphoria mechanism only makes use of the
existing dopamine in the user's brain. Once that's
gone you don't get more until your brain naturally
makes it and production is not stimulated. So you
can only be a happy drunk for a short time and the
pain of death will far outweigh that joy. |
|
| |
How interchangeable are other words with "alcohol". |
|
| |
i dinged you because the coma cabana is better.
and--the problem with cryo-preservation is cooling
the body THOUGH the temperatures you are not
referring to , in order to get to the temperatures
you are referring to . |
|
| |
despite the enormous research about various states
of ice, which are enteratining, ---we still really don't
know squat about how the cooling and freezing
process goes on in cells. |
|
| |
given the recent discoveries of our near relatives in
madagascar--lemurs----a few species of which can
actually hibernate underground for months in a very
low metabolic state----i think those lemurs probably
provide the most realistic shot at engineering a bio-
technology allowing human beings to enter stasis-or
hibernation of one sort of the other. |
|
| |
given the vast quantities of research into biological
specimens that can survive partial and full freezing--
-and their sophisticated protein and metabolic
processes for achieving this accomplishement---it
stands to reason the path forward to cryo
preservation has less to do with precisely what
temperature and pressure the human being is
subject to during the preservation state---so much
as the metabolic and protein specific processes that
safely allow the human to transition from warm high
metabolic state ( awake and asleep ) ---into cold--no
metabolic state-----and then back again. |
|
| |
it is the TRANSITIONS that are where
cryopreservation is made possible. and these
transitions are not dependent so much on
temperature, as the bodies reaction to temperature. |
|
| |
i don't think flash freezing a human being would
change the reaction to result in preservation. but
then, you'd have to do that to find out wouldn't
you?! i think you can wait for experiments like that
to happen during the next world war. some crazy
mad doctors are bound to try it. |
|
| |
//we still really don't know squat about how the
cooling and freezing process goes on in cells// |
|
| |
It depends on which "we" you're referring to,
[Slab]. |
|
| |
Mouse embryos are routinely frozen (not for sale
as canapes, but for later thawing and
implantation). Other small organisms can likewise
be frozen and thawed, as can small tissue blocks
and organs. |
|
| |
As far as anyone has been able to tell, the success
of freezing depends chiefly on the rate of cooling. |
|
| |
Regarding the heating, take a look at the Ice I - line (link). It's smooth --
it means, all we need to do, is to gradually increase the pressure, as
we gradually decrease the temperature, to enter the Ice III. We can
stay in the Ice III, up to temperature of 240 K, not below. I wonder,
would that be enough to stop deterioration? |
|
| |
If you raised the pressure to allow cooling the body
well below 0, then dropped the pressure quickly, it
might freeze fast enough. The freezing would
probably release enough heat to prevent fully
freezing, but it might be enough that everything's
immobilised and large ice crystals can't form while
you cool further to complete the freezing. |
|
| |
There could be negative effects from the pressure
drop though. |
|
| |
You could do a similar thing when converting to ice
III. Get it almost to freezing, then suddenly raise
the pressure, raising the freezing temperature.
The freezing would generate heat, raising the
tissue temperature to the new freezing point, so it
would only partly freeze instantly, but it may be
enough to stop large ice crystals forming, and buy
you time to complete the freezing by cooling. |
|
| |
Also, I found a term online, "high pressure shift
freezing" but I can't find anything about it other
than academic articles. |
|
| |
I found this link from Leica <link> which talks about freezing
samples up to a few mm in diameter at moderately high
pressure (2100 bar) to preserve microstructure for
microscopy. I wonder if anyone has tried putting a usually-
non- freezable insect through one of these to see if it
survives? |
|
| |
Cats are an insect, aren't they ... ? |
|
| |
Yes, but only after you apply the 2100 bar. |
|
| |
If you can revive a bee with a novel pressure regime kind of
ice, then you can store an entire hive mind and revive it in
the future. |
|
| |