FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups 
 ProfileProfile   PreferencesPreferences   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Forum index » Science and Technology » Chem
reactivity of esters
Post new topic   Reply to topic Page 96 of 96 [1440 Posts] View previous topic :: View next topic
Goto page:  Previous  1, 2, 3, ..., 94, 95, 96
Author Message
<lucasea@sbcglobal.net
science forum addict


Joined: 25 Mar 2006
Posts: 94

PostPosted: Tue Jul 11, 2006 2:18 am    Post subject: Re: fabulous summers for the rest of our lives Re: Summer without any rain Re: Reply with quote

<a_plutonium@hotmail.com> wrote in message
news:1152561856.445605.164820@h48g2000cwc.googlegroups.com...

Quote:
How do we do this? We do it by requiring airplanes in the apogee of
their flightpath to emit Thistle seeds and to thus imitate Pinatuba
volcano of 1992. The thistle seed will reflect sunlight and cause a
cool summer and an ample rainfall.

Lemme guess...you're being held hostage by a giant goldfinch, and being
forced to say these things. I know it's a goldfinch, because if it were a
blue jay, you'd be telling us that sunflower seeds are the answer to our
impending climatological disaster...and if it were a woodpecker, suet cakes
(although I'm going to have to get busy and build myself a garage before
that one comes to pass).

Gosh, I never realized how easy this climatology thing is until now. To
think of all the time I've wasted slaving away in a lab collecting data for
the past 25 years! Hmmph.

Eric Lucas
Back to top
<lucasea@sbcglobal.net
science forum addict


Joined: 25 Mar 2006
Posts: 94

PostPosted: Tue Jul 11, 2006 2:24 am    Post subject: Re: Cleaning zinc battery plates Reply with quote

<HLS@nospam.nix> wrote in message
news:1Evsg.63295$Lm5.35961@newssvr12.news.prodigy.com...
Quote:

"Jim Land" <RrrrFfffTttt(NO)@(SPAM)hotmail.com> wrote in message
news:Xns97F983614FD81RrrrFfffTttt4396hotm@216.168.3.44...


Since this is a museum setting, not a chem lab, it would be preferable to
do it in a safe and clean manner. Hence I'm reluctant to use any acid
that will evolve more than a few small bubbles of hydrogen gas, or use
mechanical removal (sanding, wire brusing) which would release
particulates.

On small metal samples, we have used a lapidary tumbler. The samples
may not meet your need for bright and shiny, but the surfaces are clean
and relatively reproducible

Actually, this reminds me of another possibility. Check around for tool and
die outfits in your area that have a fluidized sand bed cleaning bath. Most
are heated to burn off cutting oils, etc., and that will help loosen and
remove whatever is on your plates. A lapidary tumbler is likely to fail for
the same reason the OP described steel wool did--depending on what you
tumble the plates with, it probably won't be small enough to get into the
surface roughnesses of less than a certain size. However, in a fluidized
sand bath, that sand will scrub clean every feature that a grain of sand can
get into. Fluidized beds are omnidirectional and *amazingly* abrasive.

Eric Lucas
Back to top
Jim Land
science forum beginner


Joined: 05 Jul 2006
Posts: 6

PostPosted: Tue Jul 11, 2006 4:56 am    Post subject: Re: Cleaning zinc battery plates Reply with quote

<lucasea@sbcglobal.net> wrote in
news:gZDsg.46887$VE1.11876@newssvr14.news.prodigy.com:

Quote:
Actually, this reminds me of another possibility. Check around for
tool and die outfits in your area that have a fluidized sand bed
cleaning bath. Most are heated to burn off cutting oils, etc., and
that will help loosen and remove whatever is on your plates. A
lapidary tumbler is likely to fail for the same reason the OP
described steel wool did--depending on what you tumble the plates
with, it probably won't be small enough to get into the surface
roughnesses of less than a certain size. However, in a fluidized sand
bath, that sand will scrub clean every feature that a grain of sand
can get into. Fluidized beds are omnidirectional and *amazingly*
abrasive.



Eric, thanks for the interesting possibility. Checking around the web,
it looks as though a "fluidized sand bed cleaner" is like a sand blaster
combined with a furnace. It is typically used to remove paint and other
organics from metal parts. The combination of high temperature and
abrasive sand removes and combusts the organic coating. My experience
with the gray corrosion or oxidation on the zinc parts is that it is
*not* organic and is hard and tenacious. I'm dubious that a fluidized
sand bed or sandblaster would efficiently remove it. That's why I'm
still considering chemical means.
Back to top
William Asher
science forum beginner


Joined: 02 Jun 2005
Posts: 3

PostPosted: Tue Jul 11, 2006 6:01 pm    Post subject: Re: fabulous summers for the rest of our lives Re: Summer without any rain Re: Reply with quote

wrote:


http://www.crank.net/usenet.html

--
Bill Asher
Back to top
jmfbahciv@aol.com
science forum Guru Wannabe


Joined: 12 Sep 2005
Posts: 297

PostPosted: Thu Jul 13, 2006 9:17 am    Post subject: Re: Nanotechnology is the ultimate cure Reply with quote

In article <af3ab2d4fpo5e9pur0rsc4c3sklrqm0h0c@4ax.com>,
Gordon <gordonlr@DELETEswbell.net> wrote:
Quote:
On 11 Jul 2006 14:30:16 -0700, "bill"
ford_prefect42@hotmail.com> wrote:

[snip]

An anecdote from the farm.
My mother raises sheep for reasons known only to her. for a time,
we had a sheepdog, not the kind that chases the sheep, but the kind
that lives with them and fights off the wolves.
This dog could stand and bark all day long and the sheep would
ignore him. But on many occasions, I observed the dog give a different
bark, in response to which, all the sheep stopped eating and ran home.

There was a monkey a while back that was taught sign language. a
few dozen words, like crap, food, jump, like that. at some point in
his training, his trainer refused to give him food, to which the monkey
responded by calling him a s**t-head. without any introduction of
insults.
We are no different to the animals, we are just the next very
small step.

Bill, I grew up on a farm/ranch and can reinforce what you are
saying. Even as a child I was amazed at the level of vocal
communications between the farm animals, both domestic and wild.

A hen with a clutch of newly hatched chicks will walk around the
farmyard, clucking softly while the chicks rome out a few yards
from the hen and go about their business of hunting for something
to eat. If the hen spots something she thinks the chicks would
like she makes a different clucking sound and instantly all the
chicks respond by running to the area immediately in front of the
hen. Whom ever gets there the firstest gets the mostest, or
something like that.

If the hen spots a hawk in the air she will make a trilling sound
and the chicks will instantly respond by hiding themselves under
any available cover. Then, after the hawk has left the area the
hen will make another clucking sound and instantly all the chicks
will come out of hiding and take up where they left off.

All this is a form of language. Very primitive, but none the
less, language.

I'm not sure I'd call it primitive because the chicks didn't have
to have 25 years of schooling to understand the word "no" and
"come here".

You might replace the word language with communication and the
human holier-than-anthings might listen for more than a nanosecond.

/BAH


/BAH
Back to top
John Savage
science forum addict


Joined: 24 Mar 2005
Posts: 63

PostPosted: Fri Jul 14, 2006 4:18 am    Post subject: Re: Cleaning zinc battery plates Reply with quote

Jim Land <RrrrFfffTttt(NO)@(SPAM)hotmail.com> writes:
Quote:
Yes, the museum wants to give bright, shiny plates to the students. The
zinc plates they received from their supplier are covered with a
tenacious layer of dark grey solids which I referred to as "corrosion"
but could be oxide. Whatever the solids may be, I'm looking for a good
way to remove them.

I'm inclined towards the view that what you have there are plates with
a clean zinc surface, but because it is not smooth and shiny it seems
dull and rough or lumpy. Ordinarily, zinc shouldn't show heavy oxide
growth; zinc is the coating used on galvanised iron to protect the steel
from oxidation. And I can't see why your suppliers would supply dirty or
corroded samples.

If you want to see what zinc looks like cut the paper or plastic outer
wrap off an ordinary 1.5 volt flashlight cell from the supermarket. The
metal container this reveals is zinc, it's a darkish grey colour. It has
a shiny lustre because it has been rolled smooth and thin.

What thickness are your zinc plates? Perhaps the way they have been
manufactured/refined means they are never going to be smooth and shiny,
even when they are clean. If this is the case, and you still want them to
be shiny you will have to sand them with fine emery paper wrapped over a
wooden block or maybe use a belt sander.
--
John Savage (my news address is not valid for email)
Back to top
Jim Land
science forum beginner


Joined: 05 Jul 2006
Posts: 6

PostPosted: Fri Jul 14, 2006 5:03 am    Post subject: Re: Cleaning zinc battery plates Reply with quote

John Savage <rookswood@suburbian.com.au> wrote in
news:060714000123633.14Jul06$rookswood@suburbian.com:

Quote:
Jim Land <RrrrFfffTttt(NO)@(SPAM)hotmail.com> writes:
Yes, the museum wants to give bright, shiny plates to the students.
The zinc plates they received from their supplier are covered with a
tenacious layer of dark grey solids which I referred to as "corrosion"
but could be oxide. Whatever the solids may be, I'm looking for a
good way to remove them.

I'm inclined towards the view that what you have there are plates with
a clean zinc surface, but because it is not smooth and shiny it seems
dull and rough or lumpy. Ordinarily, zinc shouldn't show heavy oxide
growth; zinc is the coating used on galvanised iron to protect the
steel from oxidation. And I can't see why your suppliers would supply
dirty or corroded samples.

If you want to see what zinc looks like cut the paper or plastic outer
wrap off an ordinary 1.5 volt flashlight cell from the supermarket.
The metal container this reveals is zinc, it's a darkish grey colour.
It has a shiny lustre because it has been rolled smooth and thin.

What thickness are your zinc plates? Perhaps the way they have been
manufactured/refined means they are never going to be smooth and
shiny, even when they are clean. If this is the case, and you still
want them to be shiny you will have to sand them with fine emery paper
wrapped over a wooden block or maybe use a belt sander.

Thanks for the reply, John. The plates are about .12in/3mm thick, about
2in/5cm square, and look like they've been shear-cut from a large plate
of that thickness. I don't know the source, but have inquired to see if
someone knows.

I agree that, being zinc plates, they ought to at least look metallic,
even if metallic zinc is a dull gray color (dry cell battery consulted
for reference). But they don't. The crud on the surface is dark gray,
almost black, and doesn't look metallic. Besides, the crud isn't
uniform over the surface of the plates. That's what led me to believe
that there is some kind of oxidation or corrosion on top of the zinc.
Although, come to think of it, it could be something entirely different,
some outside contamination deposited on the plate.
Back to top
William P.N. Smith
science forum addict


Joined: 23 Nov 2005
Posts: 56

PostPosted: Fri Jul 14, 2006 12:44 pm    Post subject: Re: Cleaning zinc battery plates Reply with quote

Jim Land <RrrrFfffTttt(NO)@(SPAM)hotmail.com> wrote:
Quote:
I agree that, being zinc plates, they ought to at least look metallic,
even if metallic zinc is a dull gray color (dry cell battery consulted
for reference). But they don't. The crud on the surface is dark gray,
almost black, and doesn't look metallic. Besides, the crud isn't
uniform over the surface of the plates. That's what led me to believe
that there is some kind of oxidation or corrosion on top of the zinc.
Although, come to think of it, it could be something entirely different,
some outside contamination deposited on the plate.

Have these been used in batteries, and could the deposits be a result
of galvanic action, or are these 'new' from the source?
Back to top
john.spevacek@aspenresear
science forum beginner


Joined: 10 May 2005
Posts: 36

PostPosted: Fri Jul 14, 2006 1:32 pm    Post subject: Re: fabulous summers for the rest of our lives Re: Summer without any rain Re: Reply with quote

lucasea@sbcglobal.net wrote:
Quote:
a_plutonium@hotmail.com> wrote in message
news:1152561856.445605.164820@h48g2000cwc.googlegroups.com...

How do we do this? We do it by requiring airplanes in the apogee of
their flightpath to emit Thistle seeds and to thus imitate Pinatuba
volcano of 1992. The thistle seed will reflect sunlight and cause a
cool summer and an ample rainfall.

Lemme guess...you're being held hostage by a giant goldfinch, and being
forced to say these things. I know it's a goldfinch, because if it were a
blue jay, you'd be telling us that sunflower seeds are the answer to our
impending climatological disaster...and if it were a woodpecker, suet cakes
(although I'm going to have to get busy and build myself a garage before
that one comes to pass).

Eric Lucas

Thank goodness it's not a giant oriole! They prefer mealworms.

John
Aspen Research - www.aspenresearch.com
"Turning Questions into Answers"

Opinions expressed herein are my own and may not represent those of my
employer.
Back to top
mkness21@yahoo.com
science forum beginner


Joined: 17 Dec 2005
Posts: 24

PostPosted: Sun Jul 16, 2006 5:06 pm    Post subject: Re: Angular Momentum Operator Reply with quote

Farooq W wrote:
Quote:
Secondly, there is another question of evaluating an integral where
psi(x)* psi(x) are involved. Whereas psi(x) = sin kx. What would the
conjugate of a real trigonometric function i.e. what should be psi*(x)

If there is no imaginary part, then taking the complex conjugate (what
I assume you mean by *) means doing nothing, so psi(x)* and psi(x) are
exactly the same.

The rest of your stuff seemed ok to me, although I didn't check the
numbers. The 'quantum mechanical' way to think of the kinetic energy
is as an operator equal to p^2/2m, and since p = -i * hbar * d/dx, then
p^2 = - hbar^2 * d^2/dx^2, so kinetic energy = (-hbar^2/2m) * d^2/dx^2.
Back to top
rabbitispoor@bellsouth.ne
science forum beginner


Joined: 17 Jul 2006
Posts: 1

PostPosted: Mon Jul 17, 2006 7:58 pm    Post subject: Re: Cleaning zinc battery plates Reply with quote

Jim Land (NO SPAM) wrote:
Quote:
John Savage <rookswood@suburbian.com.au> wrote in
news:060714000123633.14Jul06$rookswood@suburbian.com:

Jim Land <RrrrFfffTttt(NO)@(SPAM)hotmail.com> writes:
Yes, the museum wants to give bright, shiny plates to the students.
The zinc plates they received from their supplier are covered with a
tenacious layer of dark grey solids which I referred to as "corrosion"
but could be oxide. Whatever the solids may be, I'm looking for a
good way to remove them.

I'm inclined towards the view that what you have there are plates with
a clean zinc surface, but because it is not smooth and shiny it seems
dull and rough or lumpy. Ordinarily, zinc shouldn't show heavy oxide
growth; zinc is the coating used on galvanised iron to protect the
steel from oxidation. And I can't see why your suppliers would supply
dirty or corroded samples.

If you want to see what zinc looks like cut the paper or plastic outer
wrap off an ordinary 1.5 volt flashlight cell from the supermarket.
The metal container this reveals is zinc, it's a darkish grey colour.
It has a shiny lustre because it has been rolled smooth and thin.

What thickness are your zinc plates? Perhaps the way they have been
manufactured/refined means they are never going to be smooth and
shiny, even when they are clean. If this is the case, and you still
want them to be shiny you will have to sand them with fine emery paper
wrapped over a wooden block or maybe use a belt sander.

Thanks for the reply, John. The plates are about .12in/3mm thick, about
2in/5cm square, and look like they've been shear-cut from a large plate
of that thickness. I don't know the source, but have inquired to see if
someone knows.

I agree that, being zinc plates, they ought to at least look metallic,
even if metallic zinc is a dull gray color (dry cell battery consulted
for reference). But they don't. The crud on the surface is dark gray,
almost black, and doesn't look metallic. Besides, the crud isn't
uniform over the surface of the plates. That's what led me to believe
that there is some kind of oxidation or corrosion on top of the zinc.
Although, come to think of it, it could be something entirely different,
some outside contamination deposited on the plate.

Just to make you anxious:

In the good old days zinc dry-cell casings were amalgamated with some
mercury. This must explain why the zinc filings and sulphur mixtures I
prepared as a boy chemist were so damn hard to light.
Back to top
Adam Funk
science forum beginner


Joined: 07 Jun 2005
Posts: 37

PostPosted: Tue Jul 18, 2006 9:15 am    Post subject: Re: trek Reply with quote

On 2006-07-18, Joseph Michael Bay <jmbay@Stanford.EDU> wrote:
Quote:
asw@TheWorld.com (plorkwort) writes:

In article <1152929639.548282.198800@m79g2000cwm.googlegroups.com>,
Talysman the Ur-Beatle <talysman@gmail.com> wrote:
Oh, and in case anyone is curious, D&D didn't make up "orichalcum",
either. They did make up "mithril", however.

And my office is full of orpiment! Or at least it will be if I don't get
all that realgar into airtight lightsafe containers.

Realgar shouldn't photodecay into orpiment, but into pararealgar (AsS).

But how do we synthesize kibonia?

--
Vielen Dank
Back to top
David DeLaney
science forum beginner


Joined: 08 May 2005
Posts: 20

PostPosted: Tue Jul 18, 2006 8:38 pm    Post subject: Re: trek Reply with quote

Adam Funk <a24061@yahoo.com> wrote:
Quote:
Michael Bay <jmbay@Stanford.EDU> wrote:
asw@TheWorld.com (plorkwort) writes:
And my office is full of orpiment! Or at least it will be if I don't get
all that realgar into airtight lightsafe containers.

Realgar shouldn't photodecay into orpiment, but into pararealgar (AsS).

But how do we synthesize kibonia?

I think we have to move to soviet roosia, where kibonia synthesizes YOU?

Dave "if Kibo has become nonexistent again, does that mean we have to reinvent
him?" DeLaney
--
\/David DeLaney posting from dbd@vic.com "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
Back to top
Rich Holme
science forum beginner


Joined: 06 Jun 2005
Posts: 45

PostPosted: Wed Jul 19, 2006 2:06 pm    Post subject: Re: trek Reply with quote

dbd@gatekeeper.vic.com (David DeLaney) writes:

Quote:
Dave "if Kibo has become nonexistent again, does that mean we have to reinvent
him again?" DeLaney

: (IFYQFY). Yes, and let's get it right this time. That's the trouble
with worshiping a wiki god; bozos come along and replace his
hypothalmus with "MEGAN ODONOHUE GIVES BLOW JOBS" and pretty soon he's
got orange hair and a whip. I say we revert to pre-Neptune and try
again from there. -- ~~~~

--
- Doctroid Doctroid Holmes <http://www.richholmes.net/doctroid/>
Ancient use of incendiary pigs as an anti-elephant measure is
disqualified on grounds of pigs not being cows, even when on fire.
-- John D Salt
Back to top
Otto Bahn
science forum Guru Wannabe


Joined: 08 May 2005
Posts: 101

PostPosted: Wed Jul 19, 2006 2:20 pm    Post subject: Re: trek Reply with quote

"Rich Holmes" <rsholmes+usenet@mailbox.syr.edu> wrote

Quote:
Dave "if Kibo has become nonexistent again, does that mean we have to
reinvent
him again?" DeLaney

: (IFYQFY). Yes, and let's get it right this time. That's the trouble
with worshiping a wiki god; bozos come along and replace his
hypothalmus with "MEGAN ODONOHUE GIVES BLOW JOBS" and pretty soon he's
got orange hair and a whip. I say we revert to pre-Neptune and try
again from there. -- ~~~~

If I'm dealt pocket jacks or better, I have a tendency to
go all in and get it over with. It makes the middle pairs
that much stronger when I'm short stacked.

--oTTo--
Back to top
Google

Back to top
Display posts from previous:   
Post new topic   Reply to topic Page 96 of 96 [1440 Posts] Goto page:  Previous  1, 2, 3, ..., 94, 95, 96
View previous topic :: View next topic
The time now is Sun Jun 25, 2017 10:30 pm | All times are GMT
Forum index » Science and Technology » Chem
Jump to:  

Similar Topics
Topic Author Forum Replies Last Post
No new posts acylation catayst for esters ghostwriter Chem 2 Mon Jan 16, 2006 5:21 pm

Copyright © 2004-2005 DeniX Solutions SRL
Other DeniX Solutions sites: Electronics forum |  Medicine forum |  Unix/Linux blog |  Unix/Linux documentation |  Unix/Linux forums  |  send newsletters
 


Powered by phpBB © 2001, 2005 phpBB Group
[ Time: 0.0535s ][ Queries: 12 (0.0172s) ][ GZIP on - Debug on ]