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I learned that hazelnuts are cracked by
pressurizing air and then quickly releasing
the high pressure.I suppose this would kill
any microbe and perhaps break up any virus,
for sure it would get rid of any pests and
their eggs in linnen and clothes. No?
High Pressure Air Dry Cleaning
[xaviergisz, May 30 2022]
[link]
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//I suppose this would kill any microbe and perhaps break
up
any virus, for sure it would get rid of any pests and their
eggs
[...]// |
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My instinct is probably not, almost certainly not and
maybe/sometimes respectively, for any reasonable pressure
swing. |
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Changing the atmosphere by itself may cause damage or
prevent growth in itself of course. But if we're just looking
at the pressure drop, I don't think there's much scope to do
a bacterium or virus in, because they don't contain pockets
of air. |
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Using a pressure cooker is a well known method of sterilising
glassware. You could probably do use a pressure cooker to
sterilise tough clothes. |
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How do bacteria do in a vacuum? |
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//Using a pressure cooker is a well known method of
sterilising glassware.// |
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Yes. Raising the temperature and pressure does them in.
Microbiology labs use
autoclaves to do this. This effect is mostly the high
temperature (121°C), the pressure (about 1 extra
atmosphere) is I think basically incidental. I'm not sure if
lab coats are autoclaved or just washed with lots
of bleach, but the process isn't particularly gentle on them. |
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Google gives a link to a page I can't read which says
bacteria are killed at a pressure of
60,000 pounds per square inch. But that's pretty high - over
4000 atmospheres. I found
a scientific review and eyeballed the free preview - it also
says it varies, but
includes a graph which shows /Paracoccus denitrificans/
(which is apparently typical
for vegative bacteria), which survives perfectly fine up to
300MPa (about 3000
atmospheres) and is basically completely done in by 450MPa
(4440 atmospheres). |
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//How do bacteria do in a vacuum?// |
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Bacteria vary immensely in their nature, some do much
better than others. Long
periods in a vacuum will dry most things out... but
apparently not /Deinococcus
radiodurans/ (I assume as spores).
Brief periods I think many are totally fine with - particularly
any which are on the inside of a clump. |
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I'm talking about a sudden pressure DROP that should
hopefully pop any insect and possibly even affect their
eggs, and maybe affect microbes and viruses, although they
don't have air pockets. It's worth giving it a try, but after
reading studies about pesticides in silos, following your
remarks, it most probably won't work. |
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I must say that the search for insects and air pressure did
bring me to quite a few interesting articles about insects,
one called "It's Not a Bug, It's a Feature: Functional
Materials in Insects", another "Survival Sounds in Insects:
Diversity, Function, and Evolution". and then "Why Giant
Bugs Once Roamed the Earth", and "Fly Like a Fly" about
the air pressure that flies build up with their wings to fly. |
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The article that seemed most relevant mentions pressure
once, off topic: Role of Modified Atmosphere in Pest
Control and Mechanism of Its Effect on Insects. |
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The air-pressure-alone idea by [bungston] from 2004 is very
similar, but not completely equivalent. Thanks [xaviergisz]
for pointing it out. |
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Hi [Loris], nice talking to you, for the first time, I think. If
you can't read the page Google showed you, how did you
get so much info about what it says? |
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//use pressure to replace washing// |
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I will have nightmares about your shower cubicle. |
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//Hi [Loris], nice talking to you, for the first time, I think.// |
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I boggled at this. We've both been here for 20 years. I've annotated
your ideas; you've
annotated mine. Have you never responded to one of my
comments directly before? |
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//If you can't read the page Google showed you, how did you get so
much info about
what it says?// |
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I could only read the snippet shown on the search page. The page
itself said "451
Unavailable For Legal Reasons Sorry, this content is not available
in your region."
So I read another page instead. Which did seem consistent with the
snippet,
however it didn't seem to endorse anything illegal in my region. |
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I don't know whether a pressure drop would affect insects or their
eggs. It seems
plausible. |
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If you just need a sudden pressure change, maybe a
shock wave would suffice (e.g. produced by a small
explosive). |
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