http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054

"...is extremely pure water..."

"PH: 2.0 - 3.0"

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 7/28/2011 12:24, Orchid XP v8 wrote:
> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
> "...is extremely pure water..."

Pure water is non-conductive. Water with contaminants is conductive.

> "PH: 2.0 - 3.0"

They have also filtered out the dissolved carbon dioxide from the air which 
would tend to make the water acidic.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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Le 28/07/2011 21:24, Orchid XP v8 nous fit lire :
> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
> 
> "...is extremely pure water..."
> 
> "PH: 2.0 - 3.0"
> 
more interesting: 1000ml ... 1,100g !

They also tuned the gravity field.
(ok, maybe it's bottle+water)

And what is PH ? pH yes, but PH ?

Also, notice, once open, any floating dirt in the air will contaminate
the water... in a fraction of second.

In fact, the air inside the bottle is not clean enough... they should go
the tires way: have it filled with 100% nitrogen (gas) instead of air.

Oh, btw, what about dissolved gas into the water after a storage of a
few weeks ? (closed bottled)

Post a reply to this message

On 28/07/2011 10:38 PM, Le_Forgeron wrote:
> Le 28/07/2011 21:24, Orchid XP v8 nous fit lire :
>> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
>>
>> "...is extremely pure water..."
>>
>> "PH: 2.0 - 3.0"
>>
> more interesting: 1000ml ... 1,100g !

Um, yeah.

> (ok, maybe it's bottle+water)

Perhaps. But don't bet on it!

> And what is PH ? pH yes, but PH ?

Well, ebuyer is very bad at formatting product descriptions properly. 
Most of them look like they blindly copy/pasted from the manufacturer's 
website. Hell, whoever did this probably thought that "pH" was a typo 
and helpfully "corrected" it.

> Also, notice, once open, any floating dirt in the air will contaminate
> the water... in a fraction of second.
>
> In fact, the air inside the bottle is not clean enough... they should go
> the tires way: have it filled with 100% nitrogen (gas) instead of air.
>
> Oh, btw, what about dissolved gas into the water after a storage of a
> few weeks ? (closed bottled)

OK, well I work for a lab company, and we really do use chemically pure 
water, so this is a subject I know a little bit about.

Nitrogen dissolves in water. Not as readily as some gasses, but it does 
dissolve. Apparently helium is the thing to use. (Indeed, we have 
degassing equipment that works by merely bubbling helium through the 
liquid. Any dissolved gasses tend to precipitate into the helium bubbles 
and leave with them.) Helium is very, very insoluble in liquids. I don't 
know why.

For this application (i.e., liquid cooling a computer), dissolved gas is 
unlikely to be important. Also, while dissolved CO2 might make the water 
very slightly acidic, pH 2 is *very* acidic. Either they got their 
measurements hopelessly wrong, or this "very pure water" actually 
contains some kind of additive (perhaps to limit corrosion or something).

Post a reply to this message

On 28/07/2011 09:28 PM, Darren New wrote:
> On 7/28/2011 12:24, Orchid XP v8 wrote:
>> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
>> "...is extremely pure water..."
>
> Pure water is non-conductive. Water with contaminants is conductive.

I'm aware of that. (Although apparently many people aren't.) Our lab 
water purification system (which really *does* produce "very pure 
water") measures water purity in mega-Ohms - which is amusing, given 
that it's the /non/-ionic containments which we're worried about!

>> "PH: 2.0 - 3.0"
>
> They have also filtered out the dissolved carbon dioxide from the air
> which would tend to make the water acidic.

Um, what?

pH 2 is *very* acidic. Pure water should be pH 7.0. Things having a pH 
of 2.0 include lemon juice and vinegar. (Stomach acid is pH 1.0.)

By contrast, Wikipedia quotes a pH of about 5.65 for a solution of CO2 
in water - much higher than 3 as quoted on the bottle. (Even fizzy water 
as found in fizzy drinks is only about pH 4.)

Post a reply to this message

Orchid XP v8 <voi### [at] devnull> wrote:
> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054

> "...is extremely pure water..."

> "PH: 2.0 - 3.0"

  Today's WTF is rather unusual in that it requires a degree in chemistry
rather than in computer science (which is the usual norm here). I for one
don't know what you are talking about and, for once, am too lazy to do some
google-based research. :P

  (Ok, the "requires a degree" part is an exaggeration, but you know what
I mean.)

-- 
                                                          - Warp

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Le 2011-07-29 04:12, Invisible a écrit :

> Well, ebuyer is very bad at formatting product descriptions properly.
> Most of them look like they blindly copy/pasted from the manufacturer's
> website. Hell, whoever did this probably thought that "pH" was a typo
> and helpfully "corrected" it.
>

The product description looks like it was written by Google's 
Translation tool.  "Through a reverse osmosis and mixed bed facility is 
also demineralized water. "  WAT????

> For this application (i.e., liquid cooling a computer), dissolved gas is
> unlikely to be important.

Actually, it would be.  Gas bubbles have a very different heat transfer 
coeeficient and will act as an insulator, instead of a conductor.

> Also, while dissolved CO2 might make the water
> very slightly acidic, pH 2 is *very* acidic. Either they got their
> measurements hopelessly wrong, or this "very pure water" actually
> contains some kind of additive (perhaps to limit corrosion or something).

If it contains an additive, is it still "very pure"?  Also, the bottle 
says that it is NOT an anti-corrosive agent, and that it should be mixed 
with one, preferably their own, of course.

Overall, I'm getting a bad-vibe from this product.  Just like when 
reading the description of audiophile gear.  Especially when you factor 
in the deep barytone voice that says "Feser aquaaa.  Ultra puuurrrre 
Waterrrr" when you visit their web site.

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   gmail.com     */}camera{orthographic location<6,1.25,-6>look_at a }

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On 29/07/2011 02:51 PM, Francois Labreque wrote:

> The product description looks like it was written by Google's
> Translation tool. "Through a reverse osmosis and mixed bed facility is
> also demineralized water. " WAT????

lolrus.

Have you ever tried reading the user manual for a motherboard? I'm sure 
those things are translated from Korean. Also love the way they say 
things like "option shadow video ram: causes shadowing of video ram". 
Gee, like, I couldn't figure that out. WHAT IS SHADOWING?! :-P

>> For this application (i.e., liquid cooling a computer), dissolved gas is
>> unlikely to be important.
>
> Actually, it would be. Gas bubbles have a very different heat transfer
> coeeficient and will act as an insulator, instead of a conductor.

This only matters if the gas comes out of solution. While it is /in/ 
solution, it is unimportant. Given the typical dimensions of the various 
water-cooling components, you'd have to have pretty damned big bubbles 
for it to matter.

To put it another way: Car engines are water-cooled. Typically not with 
especially pure water either...

>> Also, while dissolved CO2 might make the water
>> very slightly acidic, pH 2 is *very* acidic. Either they got their
>> measurements hopelessly wrong, or this "very pure water" actually
>> contains some kind of additive (perhaps to limit corrosion or something).
>
> If it contains an additive, is it still "very pure"?

Exactly.

Didn't the Coca-Cola company at one time try selling "extremely pure 
water" which was "triple-filtered" with "added minerals for extra purity"?

> Also, the bottle
> says that it is NOT an anti-corrosive agent, and that it should be mixed
> with one, preferably their own, of course.

You can READ that?? o_O

> Overall, I'm getting a bad-vibe from this product.

Heh, yeah. If I ever really /need/ very pure water... we lab has a 
£8,000 water purification system? Maybe I should just use that? :-P

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Le 29/07/2011 16:05, Invisible nous fit lire :
>> Overall, I'm getting a bad-vibe from this product.
> 
> Heh, yeah. If I ever really /need/ very pure water... we lab has a
> £8,000 water purification system? Maybe I should just use that? :-P

If you needed very pure water, you would go the enterprise way: ask for
allowance to pump the very old water table. Not the easy one, the very
old and very slow to fill one. Deep. Very deep. Not centuries of
filtering. Not even millenium... far more time!

Only available on continents, away from beaches.

Otherwise, use a simple cloth dryer with condensation, or just buy the
distilled water for iron.

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On 28-7-2011 21:24, Orchid XP v8 wrote:
> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
>
> "...is extremely pure water..."
>
> "PH: 2.0 - 3.0"
>

What about: 'Feser Aqua Ultra Pure Water is extremely pure water. This 
is largely removed by a double distillation process of salts, ions, 
trace elements and impurities'?
So you have pure water, then you remove it, and then you sell it?

-- 
Apparently you can afford your own dictator for less than 10 cents per 
citizen per day.

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On 7/29/2011 1:26, Invisible wrote:
> pH 2 is *very* acidic.

Oh, I got that backwards.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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On 7/29/2011 3:07, Warp wrote:
> the "requires a degree" part is an exaggeration

More like "requires remembering the first day of high-school chemistry 
class, that you've never touched since." :-)

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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On 29/07/2011 04:44 PM, andrel wrote:

> So you have pure water, then you remove it, and then you sell it?

LOL! Gotta love broken translations...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Orchid XP v8 <voi### [at] devnull> wrote:
> http://www.ebuyer.com/179913-feser-aqua-ultra-pure-coolant-1l-fa-0054
>
> "...is extremely pure water..."
>
> "PH: 2.0 - 3.0"
>
> --
> http://blog.orphi.me.uk/
> http://www.zazzle.com/MathematicalOrchid*

I'ts also absolutey germ-free, suppose that it will keep virus away from your
pc.

;-)

B Gimeno

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Le 2011-07-29 10:05, Invisible a écrit :
> On 29/07/2011 02:51 PM, Francois Labreque wrote:
>
>> Also, the bottle
>> says that it is NOT an anti-corrosive agent, and that it should be mixed
>> with one, preferably their own, of course.
>
> You can READ that?? o_O
>

Sure.

http://image.ebuyer.com/UK/P800-0179913-01.jpg

while fuzzy, it's big enough to read.

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   gmail.com     */}camera{orthographic location<6,1.25,-6>look_at a }

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>> You can READ that?? o_O
>
> Sure.
>
> http://image.ebuyer.com/UK/P800-0179913-01.jpg
>
> while fuzzy, it's big enough to read.

Barely...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 29/07/2011 05:51 PM, Darren New wrote:
> On 7/29/2011 1:26, Invisible wrote:
>> pH 2 is *very* acidic.
>
> Oh, I got that backwards.

Did I mention that my dad's a professional chemist and that I work for a 
lab company? Or that I scored 98% on my GCSE science exam? Or that my 
sister has an MSc in chemistry? Or that I personally own a chemistry 
set? :-P

Post a reply to this message

On 29/07/2011 06:15 PM, B. Gimeno wrote:

> I'ts also absolutey germ-free, suppose that it will keep virus away from your
> pc.
>
> ;-)

It's not the RNA viruses I'm worried about!

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On 01/08/2011 8:59 AM, Invisible wrote:
> Or that I personally own a chemistry set? :-P

Trust me, I own a chemistry set. ;-)
LOL

-- 
Regards
     Stephen

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On 29/07/2011 05:54 PM, Darren New wrote:
> On 7/29/2011 3:07, Warp wrote:
>> the "requires a degree" part is an exaggeration
>
> More like "requires remembering the first day of high-school chemistry
> class, that you've never touched since." :-)

Seriously. Everybody knows that water freezes at 0°C (actually no, it 
doesn't) and boils at 100°C. I've yet to meet anybody who didn't know 
that. Similarly, I was under the impression that knowing that water is 
pH 7 was common knowledge...

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On Mon, 05 Sep 2011 10:35:45 +0100, Invisible wrote:

>  that water freezes at 0°C (actually no, it
> doesn't) and boils at 100°C

It also doesn't always boil at 100C - reduce the atmospheric pressure and 
see when it boils.

Jim

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On 05/09/2011 04:43 PM, Jim Henderson wrote:
> On Mon, 05 Sep 2011 10:35:45 +0100, Invisible wrote:
>
>>   that water freezes at 0°C (actually no, it
>> doesn't) and boils at 100°C
>
> It also doesn't always boil at 100C - reduce the atmospheric pressure and
> see when it boils.

Or increase it. Or add impurities. Or whatever.

Yes, but under /normal/ circumstances, it boils at 100°C, which is why 
it's defined that way. :-P

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Le 2011/09/05 11:52, Invisible a écrit :
> On 05/09/2011 04:43 PM, Jim Henderson wrote:
>> On Mon, 05 Sep 2011 10:35:45 +0100, Invisible wrote:
>>
>>> that water freezes at 0°C (actually no, it
>>> doesn't) and boils at 100°C
>>
>> It also doesn't always boil at 100C - reduce the atmospheric pressure and
>> see when it boils.
>
> Or increase it. Or add impurities. Or whatever.
>
> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
> it's defined that way. :-P

Pure water at average sea level presure boils/condense at 100°C and 
melt/freeze at 0°C at the same presure level. Both by definition. In 
fact, it's the definition of 0°C and 100°C.
(0°F is defined as the freezing poing of sea water and 100°F as the body 
temperature of a "healthy" human male, but the "healthy" human male who 
was used for the original mesure was somewhat feverish at the time, and 
had the flue the next day...)

Change the presure and you also change freezing temperature.


Alain

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Alain <aze### [at] qwertyorg> wrote:
> Pure water at average sea level presure boils/condense at 100°C and 
> melt/freeze at 0°C at the same presure level. Both by definition. In 
> fact, it's the definition of 0°C and 100°C.

  So, does water freeze or melt at exactly 0 degrees celsius?

-- 
                                                          - Warp

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On 9/5/2011 8:52, Invisible wrote:
> Yes, but under /normal/ circumstances, it boils at 100°C, which is
 why it's
> defined that way. :-P

No it doesn't. At 100°C, it's in equilibrium. Just like at 0°C,
 it's neither 
getting more frozen or less frozen.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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On Mon, 05 Sep 2011 16:52:50 +0100, Invisible wrote:

> On 05/09/2011 04:43 PM, Jim Henderson wrote:
>> On Mon, 05 Sep 2011 10:35:45 +0100, Invisible wrote:
>>
>>>   that water freezes at 0°C (actually no, it
>>> doesn't) and boils at 100°C
>>
>> It also doesn't always boil at 100C - reduce the atmospheric pressure
>> and see when it boils.
> 
> Or increase it. Or add impurities. Or whatever.
> 
> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
> it's defined that way. :-P

Not here at 4,000 feet - "normal" circumstances here have it boiling at a 
slightly lower temperature. :P

IOW, it all depends on how you define "normal".  (Hence my suggestion of 
reducing the atmospheric pressure, because here, lower pressure is 
'normal').

Jim

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On Mon, 05 Sep 2011 13:17:32 -0400, Warp wrote:

> Alain <aze### [at] qwertyorg> wrote:
>> Pure water at average sea level presure boils/condense at 100°C and
>> melt/freeze at 0°C at the same presure level. Both by definition. In
>> fact, it's the definition of 0°C and 100°C.
> 
>   So, does water freeze or melt at exactly 0 degrees celsius?

Yes, at some altitudes, it does.

Jim

Post a reply to this message

>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>> it's defined that way. :-P
>
> Not here at 4,000 feet - "normal" circumstances here have it boiling at a
> slightly lower temperature. :P

96.2°C, a piffling 3.8° lower.

> IOW, it all depends on how you define "normal".  (Hence my suggestion of
> reducing the atmospheric pressure, because here, lower pressure is
> 'normal').

This is why the /actual/ specification is far more complicated. But for 
any sane real-world purpose, you can more or less ignore such 
technicallities.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 9/5/2011 10:47 AM, Darren New wrote:
> On 9/5/2011 8:52, Invisible wrote:
>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>> it's
>> defined that way. :-P
>
> No it doesn't. At 100°C, it's in equilibrium. Just like at 0°C, it's
> neither getting more frozen or less frozen.
>
Worse than that, in certain conditions you can "hyper-heat" water, and, 
I assume, probably super cool it, without changing state. In the former 
case you just need a container that has "no" places for bubbles to form. 
Not sure what you would need to do in the later case to make it happen, 
if you could.

Post a reply to this message

Le 2011/09/05 13:17, Warp a écrit :
> Alain<aze### [at] qwertyorg>  wrote:
>> Pure water at average sea level presure boils/condense at 100°C and
>> melt/freeze at 0°C at the same presure level. Both by definition. In
>> fact, it's the definition of 0°C and 100°C.
>
>    So, does water freeze or melt at exactly 0 degrees celsius?
>
At sea level, yes. Melt if you add energy, freeze if it looses energy, 
but stay at 0°C as long as there is still ice and liquid water.

As you climb or reduce presure, the freezing point slowly climb, but not 
much.
As you go lower or increase presure, the freezing point goes into the 
negative.

Post a reply to this message

Le 2011/09/05 18:50, Patrick Elliott a écrit :
> On 9/5/2011 10:47 AM, Darren New wrote:
>> On 9/5/2011 8:52, Invisible wrote:
>>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>>> it's
>>> defined that way. :-P
>>
>> No it doesn't. At 100°C, it's in equilibrium. Just like at 0°C, it's
>> neither getting more frozen or less frozen.
>>
> Worse than that, in certain conditions you can "hyper-heat" water, and,
> I assume, probably super cool it, without changing state. In the former
> case you just need a container that has "no" places for bubbles to form.
> Not sure what you would need to do in the later case to make it happen,
> if you could.

You can have water that stay liquid down to -10°C and possibly even 
less. You need a container with very smooth surface and no particles in 
suspention. In this state, a vibration can be just enough to cause 
almost instant crystalisation.

If you slowly heat very pure water, it can bet a good bit warmer that 
100°C before it start to boil. There will be vapour escaping from the 
surface, but no ebulition, even in a open container. It's a dangerous 
situation, as any disturbance can cause explosive ebulition projecting 
scalding water everywhere.

If you slowly cool down steam and don't give it any nucleation point, 
that steam may stay totaly gaseous at relatively low temperature. You 
get hyper-saturated steam. It appens in, and around, clouds. Again, it's 
an unstable situation and even a very faint sound, or a dust particle 
can cause almost instant condensation.

But you can't prevent ice from melting as you slowly heat it.

Post a reply to this message

On Mon, 05 Sep 2011 21:12:15 -0400, Alain wrote:

> You can have water that stay liquid down to -10°C and possibly even
> less. You need a container with very smooth surface and no particles in
> suspention. In this state, a vibration can be just enough to cause
> almost instant crystalisation.

Which is actually quite cool to see - I've seen it done with beer before.

Jim

Post a reply to this message

On Mon, 05 Sep 2011 19:32:49 +0100, Orchid XP v8 wrote:

>>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>>> it's defined that way. :-P
>>
>> Not here at 4,000 feet - "normal" circumstances here have it boiling at
>> a slightly lower temperature. :P
> 
> 96.2°C, a piffling 3.8° lower.

Which is still not 100C no matter how you slice it.  The difference in 
humidity, altitude, and other things makes cooking things that require 
precise measurements (usually baked goods) slightly different than at 
other altitudes and in other conditions.

>> IOW, it all depends on how you define "normal".  (Hence my suggestion
>> of reducing the atmospheric pressure, because here, lower pressure is
>> 'normal').
> 
> This is why the /actual/ specification is far more complicated. But for
> any sane real-world purpose, you can more or less ignore such
> technicallities.

Baking is a real-world purpose.  An awareness of the 'normal' as well as 
'current' environment are, for some things, absolutely *critical* in 
order to be successful.

Jim

Post a reply to this message

On 06/09/2011 06:25 AM, Jim Henderson wrote:
> On Mon, 05 Sep 2011 21:12:15 -0400, Alain wrote:
>
>> You can have water that stay liquid down to -10°C and possibly even
>> less. You need a container with very smooth surface and no particles in
>> suspention. In this state, a vibration can be just enough to cause
>> almost instant crystalisation.
>
> Which is actually quite cool

I see what you did there.

I've got a box of hand warmers at home. They contain a super-saturated 
solution (of what I don't know). Once you provide a nucleation point, 
the whole lot crystallises within a few seconds. It also gets quite warm 
in the process. (This is what makes it good for warming your hands.)

Post a reply to this message

On 06/09/2011 06:27 AM, Jim Henderson wrote:
> On Mon, 05 Sep 2011 19:32:49 +0100, Orchid XP v8 wrote:
>
>>>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>>>> it's defined that way. :-P
>>>
>>> Not here at 4,000 feet - "normal" circumstances here have it boiling at
>>> a slightly lower temperature. :P
>>
>> 96.2°C, a piffling 3.8° lower.
>
> Which is still not 100C no matter how you slice it.  The difference in
> humidity, altitude, and other things makes cooking things that require
> precise measurements (usually baked goods) slightly different than at
> other altitudes and in other conditions.

I would suggest that the wild variations in oven temperatures have a 
vastly bigger impact than a 4% difference in the boiling point of water.

Post a reply to this message

On 9/5/2011 6:12 PM, Alain wrote:
> If you slowly heat very pure water, it can bet a good bit warmer that
> 100°C before it start to boil. There will be vapour escaping from the
> surface, but no ebulition, even in a open container. It's a dangerous
> situation, as any disturbance can cause explosive ebulition projecting
> scalding water everywhere.
>
Or, very fast, by heating it all more or less at the same time (i.e., 
with something like a microwave oven.

Post a reply to this message

On 06/09/2011 02:12 AM, Alain wrote:

> If you slowly heat very pure water, it can bet a good bit warmer that
> 100°C before it start to boil. There will be vapour escaping from the
> surface, but no ebulition, even in a open container. It's a dangerous
> situation, as any disturbance can cause explosive ebulition projecting
> scalding water everywhere.

Legend has it that boiling water in a microwave oven has this effect. I 
don't know of an authoritative source which can confirm or refute that...

Post a reply to this message

On 9/6/2011 1:04 AM, Invisible wrote:
> On 06/09/2011 06:25 AM, Jim Henderson wrote:
>> On Mon, 05 Sep 2011 21:12:15 -0400, Alain wrote:
>>
>>> You can have water that stay liquid down to -10°C and possibly even
>>> less. You need a container with very smooth surface and no particles in
>>> suspention. In this state, a vibration can be just enough to cause
>>> almost instant crystalisation.
>>
>> Which is actually quite cool
>
> I see what you did there.
>
> I've got a box of hand warmers at home. They contain a super-saturated
> solution (of what I don't know). Once you provide a nucleation point,
> the whole lot crystallises within a few seconds. It also gets quite warm
> in the process. (This is what makes it good for warming your hands.)
Seen those. There is also some expensive shirt that was made for 
joggers, which uses a similar principle, though, in that case, I get the 
impression they formulated the material so it crystalized faster than 
normal in cold temperatures, releasing heat, but softening faster than 
normal too, absorbing it, thus keeping you cooler, or warmer, depending 
on conditions.

Always wondered, in the case of the whole "heat pack" thing though if 
you couldn't make one that did the reverse, and was "recoolable", or 
whatever. The principle being, of course, than it is rechargable, so 
long as the solution doesn't change (often the plastic is 
semi-permiable, so loses moister over time, and stops working), so when 
you let it cool slowly, it "holds" the excess energy. When you apply 
kinetic energy to it, it instantly starts losing all of what it 
retained, and crystallizes. You would basically need to do the reverse, 
somehow, for a "cold pack", crystallizing it, so as to "lose" more heat 
than it needs in a stable state, then.. there comes the rub. Other than 
that it would liquify as it absorbed the heat, instead of crystallizing, 
like the supersaturation, I am not clear how you would manage to make it 
so it could recharge effectively.

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On 9/6/2011 2:36 AM, Invisible wrote:
> On 06/09/2011 02:12 AM, Alain wrote:
>
>> If you slowly heat very pure water, it can bet a good bit warmer that
>> 100°C before it start to boil. There will be vapour escaping from the
>> surface, but no ebulition, even in a open container. It's a dangerous
>> situation, as any disturbance can cause explosive ebulition projecting
>> scalding water everywhere.
>
> Legend has it that boiling water in a microwave oven has this effect. I
> don't know of an authoritative source which can confirm or refute that...
Uh.. Mythbusters? They tried it, and it did. lol

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> Always wondered, in the case of the whole "heat pack" thing though if
> you couldn't make one that did the reverse, and was "recoolable", or
> whatever.

Hmm. Plausibly.

I would imagine, like with other refrigeration technologies, the key is 
to find a material which has a phase change at the right temperature. 
Normal hand warmers become super-saturated solutions at very high 
temperatures. If you wanted to make something cold, you'd need something 
that becomes super-saturated at a low temperature.

I'm also not completely sure of the kinetics: a hand warmer releases 
heat quickly, and absorbs it slowly. That may or may not be useful for 
cooling purposes.

Unrelated, but I note that dissolving ammonia in water is an endothermic 
reaction. That, apparently, is how Victorian icecream was made. So I 
guess the question is, WOULD YOU EAT IT? ;-)

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On Tue, 06 Sep 2011 02:41:12 -0700, Patrick Elliott wrote:

> On 9/6/2011 2:36 AM, Invisible wrote:
>> On 06/09/2011 02:12 AM, Alain wrote:
>>
>>> If you slowly heat very pure water, it can bet a good bit warmer that
>>> 100°C before it start to boil. There will be vapour escaping from the
>>> surface, but no ebulition, even in a open container. It's a dangerous
>>> situation, as any disturbance can cause explosive ebulition projecting
>>> scalding water everywhere.
>>
>> Legend has it that boiling water in a microwave oven has this effect. I
>> don't know of an authoritative source which can confirm or refute
>> that...
> Uh.. Mythbusters? They tried it, and it did. lol

I've also had it happen to me.

Jim

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On Tue, 06 Sep 2011 09:05:23 +0100, Invisible wrote:

> On 06/09/2011 06:27 AM, Jim Henderson wrote:
>> On Mon, 05 Sep 2011 19:32:49 +0100, Orchid XP v8 wrote:
>>
>>>>> Yes, but under /normal/ circumstances, it boils at 100°C, which is
>>>>> why it's defined that way. :-P
>>>>
>>>> Not here at 4,000 feet - "normal" circumstances here have it boiling
>>>> at a slightly lower temperature. :P
>>>
>>> 96.2°C, a piffling 3.8° lower.
>>
>> Which is still not 100C no matter how you slice it.  The difference in
>> humidity, altitude, and other things makes cooking things that require
>> precise measurements (usually baked goods) slightly different than at
>> other altitudes and in other conditions.
> 
> I would suggest that the wild variations in oven temperatures have a
> vastly bigger impact than a 4% difference in the boiling point of water.

My point is that 4% is still 4%.

Jim

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On Tue, 06 Sep 2011 09:04:13 +0100, Invisible wrote:

> On 06/09/2011 06:25 AM, Jim Henderson wrote:
>> On Mon, 05 Sep 2011 21:12:15 -0400, Alain wrote:
>>
>>> You can have water that stay liquid down to -10°C and possibly even
>>> less. You need a container with very smooth surface and no particles
>>> in suspention. In this state, a vibration can be just enough to cause
>>> almost instant crystalisation.
>>
>> Which is actually quite cool
> 
> I see what you did there.

Wow, *completely* unintentional, that one.  Honest. :)

Jim

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On 9/6/2011 11:34, Jim Henderson wrote:
> I've also had it happen to me.

Me too.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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Le 2011/09/06 15:59, Darren New a écrit :
> On 9/6/2011 11:34, Jim Henderson wrote:
>> I've also had it happen to me.
>
> Me too.
>

Put a pinch of croase sand in the container. It provide some angular 
surfaces that will stimulate the bubble formation as the liquid reatch 
the ebulition point. It will allow a gradual transition.
You can also rub the inside bottom of a container with fine sand paper.

About any rough surfaced material will do the trick.

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Le 2011/09/06 01:27, Jim Henderson a écrit :
> On Mon, 05 Sep 2011 19:32:49 +0100, Orchid XP v8 wrote:
>
>>>> Yes, but under /normal/ circumstances, it boils at 100°C, which is why
>>>> it's defined that way. :-P
>>>
>>> Not here at 4,000 feet - "normal" circumstances here have it boiling at
>>> a slightly lower temperature. :P
>>
>> 96.2°C, a piffling 3.8° lower.
>
> Which is still not 100C no matter how you slice it.  The difference in
> humidity, altitude, and other things makes cooking things that require
> precise measurements (usually baked goods) slightly different than at
> other altitudes and in other conditions.
>
>>> IOW, it all depends on how you define "normal".  (Hence my suggestion
>>> of reducing the atmospheric pressure, because here, lower pressure is
>>> 'normal').
>>
>> This is why the /actual/ specification is far more complicated. But for
>> any sane real-world purpose, you can more or less ignore such
>> technicallities.
>
> Baking is a real-world purpose.  An awareness of the 'normal' as well as
> 'current' environment are, for some things, absolutely *critical* in
> order to be successful.
>
> Jim

That's why, in some areas, you have cook books that gives several 
cooking times sorted by altitude ranges.

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On Tue, 06 Sep 2011 21:15:32 -0400, Alain wrote:

> That's why, in some areas, you have cook books that gives several
> cooking times sorted by altitude ranges.

Yep, indeed it is.

Jim

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On 9/6/2011 18:11, Alain wrote:
> Le 2011/09/06 15:59, Darren New a écrit :
>> On 9/6/2011 11:34, Jim Henderson wrote:
>>> I've also had it happen to me.
>>
>> Me too.
>>
>
> Put a pinch of croase sand in the container.

Yeah, because Croase sand goes so well with tea.


-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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>> Put a pinch of croase sand in the container.
>
> Yeah, because Croase sand goes so well with tea.

Personally, I put sugar in it...

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On 9/7/2011 1:12, Invisible wrote:
>>> Put a pinch of croase sand in the container.
>>
>> Yeah, because Croase sand goes so well with tea.
>
> Personally, I put sugar in it...

I just stick a spoon in it.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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