HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.chem
Subject: Re: Heavy water separation
From: del_col@ab.wvnet.edu
Date: 12 Nov 92 09:07:50 -0500
Organization: Alderson-Broaddus College

In article <1992Nov3.205140.18843@pellns.alleg.edu>, dblackbu@alleg.edu (Dave Blackburn) writes:
> In article <1992Nov3.180908.24563@kth.se> tomas_e@LINK.Physchem.KTH.SE (Tomas  
> Eriksson) writes:
> 
> |
> |And - I'd advice against drinking water that's enriched in deuterium. 
> |The rates of many reactions in the body is tunnel-effect dependent, 
> |which means that if you get a D atom instead of an H atom at the wrong 
> |place, the rate of the reaction can decrease rather much. And to 
> |deliberately include deuterium in quite a lot of molecules of your body 
> |could do strange things to your physiology. (Not that I really expect 
> |you to die of a single sip of water with a few percent deuterium in it.)
> |
> |Tomas
> |-----------------------------------------------------------------------------
> 
> Interesting. Are there any reports of the physiological effects of D2O?  
> Preferably in non-journal form, more like Scientific American level, so that 
> those of us who don't read physiological lit can understand. (Either cellular  
> or whole-animal. Both should show isotope effects if Tomas is correct about  
> H-tunneling!)
> --
> 
> * Dave Blackburn 

Dave:

	I' not a chemist, but I am a long time reader of Sci/Amer. ( that is
until it took its recent yuppieish turn)  Anyway, many and many a year ago
( in the early 1960's?) there was an article about the physiological
effects of D2O.  In both plants and animals the cumulative effect is ultimately
fatal. Chlorella algae became distorted and eventually died, and deuterized
rats developed severe kidney problems and other troubles, if I remember
correctly.  In short, ingestion of significant quantities of D2O is bad news.
Neither plants nor animals can use D2O as a substitute for honest-to-god
water.  There is, I believe, a cumulative index of S/A that should list the
articles.

J. del Col
From: carter@cemvax.cem.msu.edu (Tom Carter)
Newsgroups: sci.chem
Subject: re: ChemDraw for IBM???
Date: 11 Nov 92 13:58:17 GMT
Organization: Michigan State University, Chemistry Dept., E. Lansing, MI


In article <1992Nov9.221258.5431@newsroom.utas.edu.au> astley@franklin.cc.utas.edu.au writes:
>Fellow netters, I have just purchased an IBM 486/33 DX clone. Now, I am about
>to start writing my thesis up but want to be able to draw Chemical Structures
>like it possible to do with ChemDraw on a MacIntosh....is there a similar
>programme available for an IBM and would it happen to be shareware an which
>ftp site is it on if it exists...
>
>Thanking you all in advance,
>Tim
>
>--
>Tim Astley      | Address : 1/16 Wallace Ave., Lenah Valley, Hobart,Tas. 7008
>Chemistry Dept. |     or   astley@tasman.cc.utas.edu.au
>Uni. of Tasmania|     or   phone (002) 202158 (work) (002) 280829 (home)

I use (and like) ChemWindow, which is very like ChemDraw, and it runs under
Microsoft Windows (which you very likely got with your new computer).

Contact:
SoftShell Int'l
715 Horizon Drive, Ste. 390
Grand Junction, CO  81506
(303) 242-7502

It's not shareware, but they do have student pricing. (I can't find an 
address for a rep. down under, sorry.) HTH
===========================================================================
|        Tom Carter                    |     carter@cemvax.cem.msu.edu    |
|  Michigan State University           |     carter@msucem.bitnet         |
|    Chemistry Department              |                                  |
==========================================================================
Newsgroups: sci.chem,alt.save.the.earth
From: ladasky@netcom.com (John J. Ladasky II)
Subject: Re: Ethanol fuel
Followup-To: alt.save.the.earth
Organization: Netcom - Online Communication Services (408 241-9760 guest)
Date: Fri, 13 Nov 1992 00:36:57 GMT

ckp@netcom.com (Charles Pooley) writes:
>maierc@edmund.cs.andrews.edu (Christopher Maier) writes:
>> I'm interested in getting info on any current research in alcohol fuels.
>> primarily ethanol production.  Is anyone out there involved in this type
>> of work?  If not, does anyone know of anyone who I could correspond with
>
>I've for a long time felt that using ethanol produced by fermentation is
>fundamentaly immoral.  Using food production capacity (crops, vegetable
>matter, soil, skill and crop-growing labor, etc) to feed automobiles in
>competition with people will eventually pit automobiles against the hungry.
>
>  Let people ear what grows upon the ground and cars burn what comes from
>underground.           How 'bout that?

	I've for a long time felt (nice split infinitive there) that using
petroleum produced by the decay of ancient organic matter is fundamentally
immoral.  Using a non-renewable resource that pollutes the environment
and endangers human health when sensible alternatives are available 
(granted, ethanol fuel may not fall into this category) but underdevloped
pits automobiles against all humanity.  By postponing the technological
restructuring we will ultimately have to undertake anyway, we steal the
health of those who can't afford to move out of polluted environments, 
create the need for an occasional war, and line the pockets of people who
have managed to get the general public to bear the costs of petroleum
use.

	Let people eat what grows on the ground, let the stuff that is 
underground stay there, and let's figure out how to move around without
threatening our own existence.  How 'bout that?

	Followups to a more appropriate newsgroup.

>-- 
>Charles Pooley                  ckp@netcom.com    GEnie  c.pooley
>EE consultant, Los Angeles, CA
		^^^^^^^^^^^^^^^

	Should I have to point this out to someone who lives in LA?
-- 
== John J. Ladasky II ("ii") ========================= ladasky@netcom.COM ==
"Great composers do not borrow -	     "Talking about music is like
 they steal."  - John Ladasky	      ~ -     dancing about architecture."
(quote stolen from Stravinsky, who    o o     - Elvis Costello?  Laurie
 stole it from a statement made by     >        Anderson?  Frank Zappa?
 Pablo Picasso about painting, who    \_/    -------------------------------
 stole it from...)			     "Property is theft." - Groucho
============================================================================
Newsgroups: sci.chem
From: hpv@kelvin.uio.no (Hans Peter Verne)
Subject: Re: GRAVITY-NEUTRALIZING CHAMBER
Organization: University of Oslo, Norway
	<1992Nov9.110257.185@physc1.byu.edu>
Date: Tue, 10 Nov 1992 12:43:40 GMT


In article <1992Nov9.110257.185@physc1.byu.edu> asplundm@physc1.byu.edu writes:

>> Robby, do you do requests?  I want to know how to turn gold into lead...
                                                     ^^^^^^^^^^^^^^^^^^^
>Actually, we figured out how to do this one time.  All you need is a good
>particle accelator, and a lot of time.  We figured that given a month
>or two you could get a pretty good (5 to 10% enrichment).  It would be 
>much more expensive than just going down to the jewelery store.

I didn't know the jewelery sold lead in bulk :-)

Hugs,
Hans Peter.
Newsgroups: sci.chem
From: tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson)
Subject: Re: Heavy water separation
Reply-To: tomas_e@LINK.Physchem.KTH.SE
Organization: Royal Institute of Technology, Stockholm
Date: Sat, 7 Nov 1992 15:55:13 GMT

In article <1992Nov6.175058.7288@kth.se>, tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) writes:
>In article <1992Nov6.053218.5498@discus.technion.ac.il>, chmoris@techunix.technion.ac.il (Moris Eisen) writes:
>>Well, Based on simple facts: water has a density of 0.998 gr/cc at STP 
>>when heavy water is 1.104 gr/cc. Simple physiscs will explain whyheavy 
>>water concentration will be larger at the bottom given enough time.
>
>When conc. (D) >> conc. (1H), due to rapid proton exchange in water, all 
                ^^
Sorry, make that "<<", of course...

>deuterium is present as HDO, monodeuterated ("half-heavy"?) water. The 
>density of HDO is probably about 1.05 g/cm^3. (Note that it's impossible 
>to get a pure sample of HDO, since it would become a mixture of about 
>25% H2O, 50% HDO and 25% D2O - neglecting free energy differences between 
>the three species which may promote >50% HDO or <50% HDO - very rapidly.)

Well, why guess, when we have formulas!? Using the equation for 
equilibrium between sedimentation in earth's gravitational field and 
diffusion (can be found in just about any colloid or biophysical 
chemistry textbook), using 0.1 m height difference, and the density 1.05 
for HDO, I got

	ln (c_2/c_1) = 0.000 000 4

I.e. when we reach equilibrium, the concentration of HDO at the bottom 
is 1.000 000 4 times that close to the surface.

Equilibrium requires that we have no thermal gradients in the sample, 
and not the slightest vibration. This also requires that no (net) 
evaporation takes place, otherwise you will get convective mixing of the 
sample due to evaporative cooling. (Btw, the formula used is perhaps not 
100% correct in this case, as it uses a Stokes-Einstein expression, 
which works good for a small spherical particle in water, but perhaps 
not as good for a HDO molecule in H_2O - but the error shouldn't be 
enormous)

How long would it take to reach equilibrium, if we can maintain the 
unrealistic conditions necessary that long? "Infinite time" the 
mathematician would say, but let's calculate how long time it takes for 
a water molecule to diffuse 0.1 m:

	average square displacement in a given direction = 2Dt

where D in this case is the self-diffusion coefficient of water, which 
is about 2E-9 m^2/s, giving us t as about *one month*.

From a chemical engineering standpoint, I wouldn't call this method of 
separation economically feasable. :-)

Tomas
-------------------------------------------------------------------------------
Tomas Eriksson                                          tomas_e@physchem.kth.se
            Surface Force Group, Department of Physical Chemistry,
               Royal Institute of Technology, Stockholm, Sweden

"These latter-day practitioners of surface chemistry reflect a lingering of the
adventurous spirit of the Enlightment" -- Charles Tanford
Newsgroups: sci.chem
From: jeroen@dxcern.cern.ch (Jeroen Belleman)
Subject: Gold dust a fire hazard?
Organization: CERN European Laboratory for Particle Physics
Date: Wed, 11 Nov 1992 16:18:21 GMT


I received my Goodfellow catalogue today was leafing through it when
my eye fell on this oddity:

High purity gold dust with particle size of 250 micrometres or less is
marked as being highly flammable.
In fact, so is platinum.

I'm no professional chemist, but it strikes me as odd that that these
metals would burn.

Anyone knows for sure?

Best regards,
Jeroen Belleman
jeroen@dxcern.cern.ch
From: chmoris@techunix.technion.ac.il (Moris Eisen)
Newsgroups: sci.chem
Subject: Re: chem abstracts via internet
Date: 6 Nov 92 08:38:01 GMT
Reply-To: chmoris@techunix.technion.ac.il (Moris Eisen)
Organization: Technion, Israel Inst. of Technology

In article <1992Nov4.093940.609@cine88.cineca.it> lunazzi@boifcc.cineca.it (Mauro Andrea Cremonini) writes:
>In article <1992Nov4.054752.2805@samba.oit.unc.edu> Stephen.Urquhart@launchpad.unc.edu (Stephen Urquhart) writes:
>>G'day:
>>
>>I would like to be able to do chem abs searches via telnet. I am more than
>>willing to pay a fair price for the service - the most important issue is
>> autonomy from an ill run library computer search service. (I'm not from
>>Univ. of North Carolina...I just rn from here... so I'm not slandering the
>>unknown but probably nice folks at unc ;-))
>>
>>Does anyone have an email contact they c ould send me?
>>
>>Stephen Urquhart
>>urquhart@mcmail.cis.mcmaster.ca
>>stephen.urquhart@bbs.oit.unc.edu
>
>                      Yes! Write to Jim Corning jfc88@cas.org .

>                      Mauro

Dear Stephen
You can telenet to STNC.CAS.ORG that's the STN on line and from there you are
already in the CAS on line.
Bye
Dr. Moris S. Eisen
Department of Chemistry
Israel Institute of Technology
Israel
Newsgroups: sci.chem
From: "david gebhardt" <david.gebhardt@canrem.com>
Subject: picric acid explosion
Reply-To: "david gebhardt" <david.gebhardt@canrem.com>
Organization: Canada Remote Systems
Distribution: sci
Date: 5 Nov 92 12:16:37 EST

On 11-05-92 at 1:27am, Hans Peter Verne wrote to All:

>2 C6H3O7N3 -----> 3 N2(g) + 3 H2O(g) + 5 CO2(g) + CO(g) + 6 C(s) (soot)
HP>                                          ^^^^^^             ^^^^

HP>At temperatures above 706 C, the reaction will be (according to my old book
HP>on inorganic chem.):

HP>   CO2 + C  -->  2 CO

I had a different equation that had all CO2 and no CO. My point is this:

During the reaction, there is a rapid increase in both energy and
temperature. CO2 gives off approx. 3.5 times as much heat as CO, so you
either need a reaction involving a lot of CO, or the other products
have to be present in larger quantities to make up the required energy.

The CO2 and C are propelled out from the blast area and undergo rapid
cooling in the surrounding air. If there is no fire, there will be a
rapid temperature drop and decrease in energy. Some of these may be
attributable to conversion of CO2 to CO, but there will also be rapid
dissipation of the heat.

The conversion of CO2 to CO should depend on the reaction rate for the
conversion and the amount of time for the temperature drop to occur. If
the reaction is almost instantaneous, you should end up with lots of CO.
But if the temperature drop is too fast fot the reaction, you may only
end up with a little CO.

David Gebhardt
ComputerPlus
---
  DeLuxe 1.25 #8170  Electricity was invented by rubbing cats backwards
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
From: tgtbtk@tb3.chem.tue.nl (Toine Kuiper)
Newsgroups: sci.chem
Subject: Chemwindow OLE support ?
Date: 8 Nov 92 10:58:37 GMT
Reply-To: tgtbtk@chem.tue.nl

The version of Chemwindow (classic and pro) I own doesn't support OLE. 
I would like to know if more recent versions of Chemwindow support OLE.

Thanks in advance.

Newsgroups: sci.chem
From: rfedkiw@olympic.math.ucla.edu (Ronald Fedkiw)
Subject: Equations for constant density reactions]`
Organization: UCLA Mathematics Department
Distribution: usa
Date: Thu, 12 Nov 92 20:14:18 GMT


As a model for chemically reacting flow....         
First convection with no reaction
Second reaction with no convection
(I use a Strang time spliting procedure)

Does this sound reasonable???

Now, the second part means that a reaction is taking place
in a control volume --- constant density,                  
                    --- pressure and temperature vary

If Yi is the mass fraction of the ith species then
the ODE's look like:
       
          dYi   production rate of species i
          --- = ----------------------------
          dt    density of control volume

But how do I account for temperature and pressure change at 
each time step. (I know just update, easy, but I'm looking
for the more correct coupled ODE's)

I've seen a coupled ODE for temp in a constant pressure 
reaction, but have never seen the constant density stuff.
 
--
Ron Fedkiw (rfedkiw@joshua.math.ucla.edu)

A plan is made by someone who is sitting and thinking ...
while others are doing.
Newsgroups: sci.chem
From: LJ10717@LMSC5.IS.LMSC.LOCKHEED.COM
Subject: Re: MSDS information required
Organization: Lockheed Missiles & Space Company, Inc.
Date: Thu, 12 Nov 92 18:37:36 GMT


To whom it may concern,

There exists such an agency - online - that provides the information you are
requesting. The National Library of Medicine (NLM) provides *online* services
for chemical (CHEMLINE), toxicological (TOXLINE & TOXNET), health (DIRLINE) and
a host of other services that various health & safety organizations require.

You can contact them directly through the following address:

                         Specialized Information Services
                         National Library of Medicine
                         8600 RockvillePike
                         Bethesda, MD.  20209
                         Tele.  (301) 496-1131

Bonne Chance!
------------------------------------------------------------------------------
Diamond@lmsc.lockheed.com               "Live life as an exclamation NOT
                                         as an explanation!"
                                            -JH Jackson Brown Jr.
------------------------------------------------------------------------------
Note: if the above information is incorrect please notify via email *thanks*
From: bjgaed@bb1t.monsanto.com
Newsgroups: sci.chem
Subject: Re: chemometrics: statist
Date: 4 Nov 92 07:33:06 CST
Distribution: sci
Organization: Monsanto Company, St. Louis, MO

In article <1992Nov1.4261.6313@dosgate>, "david gebhardt" <david.gebhardt@canrem.com> writes:
> On 10-31-92 at 5:04am, Bjgaed wrote to All:
> 
> BD>My question is this:  What does the neural net approach get you that
> BD>the statistical approach does not?  Obviously you need a good deal
> BD>more computing muscle for the neural net approach, so how big a bang
> BD>do you get for the bucks?
> 
> I couldn't say for sure, but I would venture that the power of
> prediction for the neural net would be greater than that for a
> statistical method. Of course, that is also going to depend on the
> neural net configuration and the amount of training that the net has
> received.

Why would you "venture" that?  This is still my question:  Is there 
any basis for assuming better predictive power for the neural net 
approach over the statistical approach?

The software I was looking at was a pretty simple-minded neural net:  
About 10 inputs, 1 output, and 1 hidden level.  Just about the 
simplest neural net you can imagine, and it neede a Silicon Graphics 
workstation to run.  As long as I have enough experiments for the 
degrees of freedom involved I could do this one on a desktop PC or Mac 
in a walk with any number of inexpensive statistical saftware 
packages. 

> The problem is that it is not an easy concept to explain. The neural net
> uses past experiences to predict future occurrences and adapts itself.
> This should make it more accurate than a simple statistical approach.

Why?  Really, no flame intended.  As I understand it neural nets have 
the capability of using a much wider variety of functions than linear 
or polynomial multiple regression, but doesn't that depend on the 
particular "teaching" algorithm the neural net uses? (The software 
developer was very reluctant to talk about the algorithm; 
understandable, as it is probably proprietary.)  And can't you do 
the same in regression by transforming your input data, like using 
-log(response) instead of the raw response when doing QSAR?
 
> David Gebhardt (david.gebhardt@canrem.com)



--Electric Monk            (Bruce Gaede); 
                            e-mail: bjgaed@ccmail.monsanto.com

"...and then time started seriously to pass."
--Douglas Adams, _Dirk Gently's Holistic Detective Agency_
From: finkel@sirius.llnl.gov (Bob Finkel)
Newsgroups: sci.chem
Subject: CH3OH + HNO3 -> blue color. What is it?
Keywords: methanol, nitric acid
Date: 13 Nov 92 19:20:34 GMT
Organization: Lawrence Livermore National Laboratory

We are doing a set of aerosol analyses which require extracting
particulates from filters. Recently we began using teflon filters for
the first time. In our procedure we sonicate the filter, which has been
wetted with a small amount of methanol, in 50% HNO3. We found that
sonicating methanol and HNO3 yields a blue-colored solution. The color
decomposes on further heating. This reaction is new to me and I would
be interested in any hints about what we might be seeing.
From: cs90mdh@cen.ex.ac.uk
Newsgroups: sci.chem
Subject: IBM PC chemistry program
Date: 10 Nov 92 17:18:50 GMT
Organization: University of Exeter, UK.


I am going to write a package which could be used as a teaching aid in schools
and possibly universities - a 3d molecular rendering program. ( Displays
molecules with the 'ball and stick' model, which the user can pan around in
real time )

I would appreciate some feedback by chemistry teachers / would-be teachers
as to the usefullness of such a package and for any ideas to be included. Any
comments would be much appreciated, such as functionality within the package
and the user-interface.

(eg how important is a fast update, would shading be required, what 
information would be useful to display with each atom/bond, would it be
vital for students to use the package or could it just be demonstrated by
the teacher etc...)

Also, how would such a program fit in with current teaching methods
( at schools, colleges or universities) ?

Thanks in advance,

				Mark.H.
Newsgroups: sci.chem
Subject: ZPE differences
From: ivar@chem.ut.ee (Ivar Koppel)
Date: Wed, 11 Nov 1992 07:52:08 GMT
Organization: Tartu University, Department of Chemistry

Dear netters.
I'm starting a little project for quantum chemical calculations
of gas-phase acidities and/or keto-enol tautomerism. I have been
suggested, that in such cases in adition to SCF energy differences
also differences in zero point vibrational energies (ZPE) play important
role, but I have no knowledge how to calculate these energies with
MOPAC 6.0 or Gaussian 88, whitch are the programs available for me now.
Any hint will be appriciated.

Koit Herodes, student at Tartu University, Estonia
From: nuke@reed.edu (Bill Newcomb)
Newsgroups: sci.chem
Subject: Re: methanol "luminescence"
Date: 11 Nov 92 06:07:41 GMT
Article-I.D.: reed.1992Nov11.060741.26311
Organization: Reed College, Portland, OR

ebstokes@maxwell.crd.ge.com (Ed Stokes) writes:
>methanol. Just for kicks, we tried looking at pure,
>"spectrophotometer grade" methanol with a 280nm laser
>excitation (doubled 560nm dye laser). Much to our
>surprise, the methanol shows a visible blueish fluorescence
>around the laser beam as it passes through.

What kind of power are you putting into the sample? With sufficient power I
suppose it might be possible to "burn" the methanol with the dissolved
gases, or do some other kind of chemistry. With sufficient flux you could be
seeing some result of multiphoton absorption, which would correspond to
putting 140 nm light in, probably plenty to pump electrons into higher
states. 

I would save the sample you saw it in, and try the experiment again (I don't
wish to insult anyone's intelligence here, but certain people have gotten
pretty red in the face before for not doing so :-) in a number of different
cuvettes. You were using glass, were you not? If not, all bets are off--MeOH
is a fantastic solvent for fluorescent molecules in plastics. In fact, MeOH
is also a great solvent for metal ions, some of which have absorptions all
the way into the visible-- a nitric acid rinse or two should get rid of it.

It is entirely possible that your solvent is, in fact, contaminated. It
seems, though, that a lot of other things might have happened along the way.

Come to think of it, I take back the bit about MPA up there. Unles you were
actually doing some reaction, I don't know why MeOH would emit considerably
redder than your UV even if you were getting excitation. Oops, it appears
I've posed another question:-)

nuke@reed.edu
Bill Newcomb

>
>Now every book I can find tells me what I already knew: that
>methanol is transparent at 280 nm, and has only one
>absorption band in the uv, at about 180 nm. So, this
>must be some impurity in the "spectrophotometer grade"
>methanol.
>
>Does anyone have any experience/advice on this matter ?
>
>Ed Stokes
>ebstokes@crd.ge.com


--
~/.oo