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chemistry --> chemical engineering
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rekuci@gmail.com
science forum addict


Joined: 22 Sep 2005
Posts: 98

PostPosted: Thu Jan 05, 2006 3:26 pm    Post subject: Re: High Pressure Separation Process Reply with quote

vjp2@panix.com wrote:
Quote:
Suppose you have a separation process one mile deep: How can you
use the pressure to your advantage in filtration or even distillation?

In filtration, you usually apply vacuum on the filtrate side of the
filter to speed it up. Only a pressure differential, not a high
pressure on both sides, will help you there. Same for reverse osmosis,
which couples normal osmotic pressure due to a chemical potential
difference across a semi-permeable membrane with an extra applied
pressure ONLY on the high-concentration side, to shift equilibrium. If
you had a reverse osmosis process under water, you would have a higher
pressure on both sides of the membrane, which wouldn't help you at all.
As far as water purification by distillation, high pressure is not
going to help you either because you are usually trying to remove
non-volatile components (salts, metals). This means at high pressure,
you'll just have to pump more heat into the water to get it to
vaporize. Elevated pressure is useful for many distillations, but
certainly the cost of building, operating, and maintaining an
underwater facility is much more than any energy cost to generate high
pressure in the column on land...

In short, desalination and water purification plants are already
located where they're most economical - on land and next to a source of
water.

Quote:
I am thinking of water purification, actually.
Someone (a p-chem prof, actually) had once told me something about
there actually being a voltage drop (caused by pressure difference)
when you go that deep under water?

Huh? Voltage drop? There's a lot of pressure due to the sheer weight of
the water, and it's not a pressure drop. Just pressure.
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Uncle Al
science forum Guru


Joined: 24 Mar 2005
Posts: 1226

PostPosted: Wed Mar 15, 2006 4:54 pm    Post subject: Re: Salicylic acid handling Reply with quote

Nicolas DELFAU wrote:
Quote:

Dear all,

I have one single question regarding the handling of salicylic acid. This
acid is a very volatile fine powder, which easily adsorb on skin, leading to
unwanted irritation. It also tends to agglomerate and is quite impossible to
solubilize afterwards. So we spread it manually through a mesh onto our
formula, which is the hardener of a high-solids epoxy.
My question is the following : how can one handle it safely, i.e. without
skin irritation ? Does someone have any idea about that ?
Best regards.

If you must sprinkle it over a large area... electrostatic platen. No
dust gets loose. Remember the megaohm resistors lest the high voltage
arc.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz3.pdf
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Bob111
science forum Guru Wannabe


Joined: 13 Jan 2006
Posts: 115

PostPosted: Mon Mar 20, 2006 7:00 am    Post subject: Re: Ink Reply with quote

<mshawjr@frontiernet.net> wrote in message news:J6qTf.1038$tT.939@news01.roc.ny...
Quote:
Man I have found this site that has the cheapest ink for any printer.
You can compare prices and then review the companies on service and
quality. <http://www.imagraphix.com> Let me know what you think

Why are spammers always so transparent? These things are always the same.

Bob
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The Nolalu Barn Owl
science forum beginner


Joined: 21 Mar 2006
Posts: 1

PostPosted: Tue Mar 21, 2006 1:46 am    Post subject: Re: Ink Reply with quote

On Mon, 20 Mar 2006 12:08:42 GMT, mshawjr@frontiernet.net wrote:

Quote:
Sorry guys. The spam stuff was not my intent. I do oppoligies and won't
happen again. I have never been on newsgroups before and not sure how to
work them. I hope you guys can forgive a bad choice. Murphey
BS. For a new guy you managed to hit every single, non related NG I

subscribe to. You are not a beginner any more than I am Mother
Theresa.
-
Regards
Gordie
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John P Bengi4
science forum beginner


Joined: 21 Mar 2006
Posts: 2

PostPosted: Tue Mar 21, 2006 3:14 am    Post subject: Re: Ink Reply with quote

Do you always answer bots?

LOL

"The Nolalu Barn Owl"
<&#103&#111&#114&#100&#105&#101&#64&#110&#111&#108&#97&#108&#117&#46&#
111&#110&#46&#99&#97> wrote in message
news:immu12po4subg9u67n4eddt95sp7c9p7s0@4ax.com...
Quote:
On Mon, 20 Mar 2006 12:08:42 GMT, mshawjr@frontiernet.net wrote:

Sorry guys. The spam stuff was not my intent. I do oppoligies and
won't
happen again. I have never been on newsgroups before and not sure
how to
work them. I hope you guys can forgive a bad choice. Murphey
BS. For a new guy you managed to hit every single, non related NG I
subscribe to. You are not a beginner any more than I am Mother
Theresa.
-
Regards
Gordie
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Jerry Avins
science forum Guru


Joined: 03 May 2005
Posts: 534

PostPosted: Fri Jun 23, 2006 12:52 am    Post subject: Re: Tall Tales of The Bible Belt Reply with quote

interesting122000@yahoo.com wrote:
Quote:
Tall Tales of The Bible Belt

Another edition of "Tall Tales of The Bible Belt" has been released.

This group is about process control, not mind control.

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ
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Radium
science forum Guru Wannabe


Joined: 15 Dec 2005
Posts: 241

PostPosted: Sun Jun 25, 2006 4:44 pm    Post subject: Re: Anthracite's Aromatic Compounds Smell Like Paradise Reply with quote

Farooq W wrote:
Quote:
Radium wrote:

Some of the rural areas of WV, where NG is not readily available and many
folks have coal stoves, burning coal smoke in the winter smells to me mostly
like aromatic organic compounds.

I love this smell.

Coal tar distillates (the volatiles that
distill from coal on thermal processing, such as burning) include a large
number of relatively simple aromatic compounds (toluene and other
substituted benzenes), hetero-substituted aromatic compounds (substituted
pyridines, anilines, phenols), and polycyclic aromatic compounds
(naphthalenes, anthracenes, phenanthrenes, pyrenes, etc.)

Yes. The above compounds are included in the countless long list of
chemicals that give anthracite its heavenly flavor.

These "heavenly flavours" would send people (who love these smells) to
heaven or hell by cancer!

Well, too much of anything -- good or bad -- is bad.

> Mr. Radium should tell us how real radium smells like?
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Bob111
science forum Guru Wannabe


Joined: 13 Jan 2006
Posts: 115

PostPosted: Sat Jul 08, 2006 1:25 am    Post subject: Re: Ink Reply with quote

"The Nolalu Barn Owl"
<&#103&#111&#114&#100&#105&#101&#64&#110&#111&#108&#97&#108&#117&#46&#111&#110&#
46&#99&#97> wrote in message news:immu12po4subg9u67n4eddt95sp7c9p7s0@4ax.com...
Quote:
On Mon, 20 Mar 2006 12:08:42 GMT, mshawjr@frontiernet.net wrote:

Sorry guys. The spam stuff was not my intent. I do oppoligies and won't
happen again. I have never been on newsgroups before and not sure how to
work them. I hope you guys can forgive a bad choice. Murphey
BS. For a new guy you managed to hit every single, non related NG I
subscribe to. You are not a beginner any more than I am Mother
Theresa.

Is that you Mother?

Bob
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Uncle Al
science forum Guru


Joined: 24 Mar 2005
Posts: 1226

PostPosted: Tue Jul 11, 2006 2:19 pm    Post subject: Re: highest-k tubing that won't corrode in Lithium Chloride? Reply with quote

dances_with_barkadas@yahoo.com wrote:
Quote:

seek tubing that won't corrode in strong solutions of Lithium Chloride,
but conducts heat very well. For service in auto/truck exhaust
temperatures.

Corrosion resistance will also depend on whether there is oxygen
(early and middle transition metals vanish), carbon monoxide (middle
and late transition metals vanish), or hydrogen (ferrous
embrittlement) present. Will there be contamination by transition
metal ions like iron or copper? Pitting!

Sintered beryllium oxide, silicon carbide, or alumina come to mind.
Hastelloy C-2000. Oh yeah... Is this Enviro-whiner spew or does the
cost matter?

Lithium is massively toxic. Small doses cause mental aberrations and
depression.

Googole
"green death" corrosion 430 hits
"green death" pitting 311 hits
"yellow death" corrosion 41 hits
"yellow death" pitting 23 hits

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz3.pdf
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