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Author Topic: Why Does CO2 Escape From An Enclosure More Easily Than Air?  (Read 61230 times)

Offline damocles

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Why Does CO2 Escape From An Enclosure More Easily Than Air?
« Reply #25 on: 02/06/2011 01:04:47 »
Dr John Christie here under a pseudonym (didn't realize that that was what I was setting up when I registered).
I am a "Mad Scientist", not a major expert, but do have some genuine knowledge in this area.

Here is a review article -- not quite on this topic, but it provides a useful clarification of some of the terms that are being used, and a diagram that displays quite clearly three different mechanisms whereby a gas might escape a container.
http://www.benthamscience.com/cheng/samples/cheng%201-1/Sandra%20E.%20Kentish.pdf

In my original MadSci reply at
http://www.madsci.org/posts/archives/may98/895552329.Ch.r.html
--"soluble" was in inverted commas as an implicit warning. I did mean soluble, but people usually think in terms of simple gas in liquid or solid in liquid solutions; solutions in a matrix of rubbery polymer as solvent are more complicated, and do not behave in exactly the same way.
-- "thread a maze, at best" meant exactly what it said. "Thread a maze" is only an option if open microchannels are available -- the first or "Knudsen diffusion" option of the three mentioned in the pdf.

On the underlying topic I have a very firm view that the ice core CO2 record is trustworthy. Regardless of the detail of mechanism or modelling, ANY diffusion process can only move a substance from a region of higher concentration to a region of lower concentration. The fact that sizable fluctuations in ice core CO2 analyses can be seen back to 300kyr or longer is a clear indicator that diffusion over the milennia has been only a minor process. The resolution of ice core analyses is 100-200yr for Vostok and most other cores; 20-30 yr for Law dome:
http://cdiac.ornl.gov/trends/co2/lawdome.html
and google for other refs.

Temporal resolution is a clear indicator of the extent of diffusion, regardless of process.
 

Offline Bored chemist

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« Reply #26 on: 02/06/2011 07:04:06 »
Bored chemist I couldn’t find anything about latex dissolving CO2 and mostly its the other way round so are you right about that or just guessing. One site says that the formula for pure latex is C3H3N so as you’re a chemist does that tell you anything about CO2 dissolving in it.


As a chemist I know  that formula is just plain wrong. It's close to right for nitrile gloves.
All things dissolve in all other things  to some extent (unless they react).

RD's suggestion will get upset by the CO2 dissolving in the water in the manometer.
 

Offline Peter Ridley under another name

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« Reply #27 on: 02/06/2011 21:14:14 »
Hello Dr. Christie thanks very much for commenting here so quickly because ideas from somebody who knows about the processes of molecular movement through pores and channels that approach the size of those molecules is really needed here. You may call yourself a mad scientist but at least you look like you understand the science. I don’t know if anyone else commenting here is a scientist so I think what you say may be more dependable. After all you do have a high qualification and are a science educator. You appear to have knowledge about my question that nobody else here seems to have so please tell me more about how those molecules move through pores and channels that are a similar size to the molecules.

Pete Ridley was asking about the size of molecules and talked about collision diameter being the wrong one and kinetic diameter being the one to use so was he wrong about that? He said that
Quote
For many of the gases that make up the atmosphere there is little difference between collision and kinetic diameter, as seen in the listing below, but for CO2 this is not the case. Consequently, as the ice is compressed and pressure builds up in the pockets the CO2 molecules (and any smaller ones) escape from the pockets and move down the pressure gradient towards the surface, long after the larger gases like N2, O2, Ar and CH4 are trapped
http://www.thenakedscientists.com/forum/index.php?topic=38675.0 so that other thing is about a pressure difference. I think he was talking about the air in the bubbles getting squashed and the pressure inside being higher than outside so isn’t that what happens in a balloon and why the gas gets out to the air and not from the air into the balloon?

You also said about
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if open microchannels are available -- the first or "Knudsen diffusion" option of the three mentioned in the pdf
I haven’t read the pdf yet but will do next but Pete Ridley also talked about that Knudsen diffusion and said on one of the sites that he linked to that
Quote
Some of the pores will be so small that not all of the different types of gas molecules in the air mixture can pass, allowing only the smallest ones through, including CO2, but preventing N2, O2 and CH4. Other pores will be large enough for the whole air mixture to diffuse. I also hypothesise that both Fickian and Knudsen diffusion takes place, depending upon the size of those pores, with Fickian being relevant in the upper layers of firn and Knudsen at the approach to “complete” close-off and a gradual shift in emphasis down the ice sheet
http://www.climateconversation.wordshine.co.nz/2011/03/fallen-snow/ so was he wrong again?
« Last Edit: 02/06/2011 21:22:02 by Yelder »
 

Offline Peter Ridley under another name

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« Reply #28 on: 02/06/2011 21:18:56 »
Bored chemist you said that the formula for pure latex of C3H3N
Quote
is just plain wrong
so can you say what it really is?. You also said
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All things dissolve in all other things to some extent (unless they react)
but when I think of something dissolving I think of it going into a liquid and forming ions. I googled “define dissolve” and it said
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to  make  a  solution  of,  as  by  mixing  with  a  liquid;  pass  into  solution:  to  dissolve  salt  in  water
(ttp://dictionary.reference.com/browse/dissolve which is how I picture it. I also looked at “define solution” and it said
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A homogeneous mixture of two or more substances, which may be solids, liquids, gases, or a combination of these
so it looks I was wrong and solids can dissolve into solids and liquids into liquids and gases into gases and all that so whats the difference between a mixture and a solution? Like the atmosphere is a mixture of different gases but is that a solution or a sponge sucks up water but are they solutions? I didn’t think they were. What makes a solution different from a mixture and how does CO2 going into latex make it a solution? Does the CO2 and latex form a homogenous mixture?

Princeton University says
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any combination of two different materials which don't react is a mixture, while solutions are a special kind of mixture where mixing occurs at the molecular level. Thus, all solutions are mixtures, but not all mixtures are solutions. To make the distinction clear, we'll use the phrase "physical mixture" to denote a mixture which is not a solution. So, by this definition, both muddy water and Kool-Aid®  are mixtures of solid and liquid (that's how they're prepared), but only Kool-Aid is a solution
http://www.princeton.edu/~pccm/outreach/scsp/mixturesandsolutions/background.htm. That tells me that if CO2 dissolves in latex then it must react with the latex but does it and if it does why does it come out again by itself.

You also said that
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RD's suggestion will get upset by the CO2 dissolving in the water in the manometer
and Ive read that it does do that but it also gets put out by water depending on how hot it is. If there is a full amount of CO2 in the water to start with why would any more dissolve and what would stop some coming out of the water if the temperature went up during the experiment so it could happen either way couldn’t it.
 

Offline damocles

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« Reply #29 on: 02/06/2011 22:16:22 »
When chemists talk about the shape of molecules, they often get it quite wrong -- including those who write textbooks! Chemists have been in the habit of playing too much with ball-and-stick or wireframe molecular models, and too little with space filling models.

Thus I hear of the CO2 molecule being in the shape of "a needle" in this thread. CO2 is approximately an ellipsoid of rotation, with a long axis around 560 pm and identical short axes around 350 pm. It is thus the shape of an American football, or a peanut. A peanut is a good one because the only way to describe the shape of a water molecule is not a boomerang or a "V-shape", but a cashew nut!

From Yelder
Quote
Pete Ridley was asking about the size of molecules and talked about collision diameter being the wrong one and kinetic diameter being the one to use so was he wrong about that?

Collision diameter and kinetic diameter both work out to be an average of sorts between the lengths of the three principal axes. That is, both are strictly larger than the smallest axis and strictly smaller than the longest axis. There is a "fuzziness" of about 10 to 20 pm in the axis length, connected with what one regards as the outer boundary of an atom -- hence the "about" in the football measurements given above. Collision diameter is well defined; kinetic diameter is much more context dependent, and for that reason alone should probably be avoided unless you are reproducing an exact context.

But in this case, if you work along the same lines as the pdf reference, you will realize that there is a lot that does not make much sense. From Pete Ridley:
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Some of the pores will be so small that not all of the different types of gas molecules in the air mixture can pass, allowing only the smallest ones through, including CO2, but preventing N2, O2 and CH4. Other pores will be large enough for the whole air mixture to diffuse. I also hypothesise that both Fickian and Knudsen diffusion takes place, depending upon the size of those pores, with Fickian being relevant in the upper layers of firn and Knudsen at the approach to “complete” close-off and a gradual shift in emphasis down the ice sheet

As the pores get smaller, Knudsen diffusion clearly takes over, and the context-dependent kinetic diameter approaches closer to the smaller axis lengths of the molecule. But when the pores reach the size where they start to block the passage of some molecules, I think the view taken in the pdf is the best approach -- the description should be in terms of a different mechanism-- molecular sieving.

However, for the overall discussion purposes, the detail of diffusion mechanism is totally irrelevant! This is the most important point in my previous post. If diffusion of carbon dioxide through ice were a serious problem for the glacial record of past atmospheric CO2, then ice cores would be showing higher carbon dioxide levels, closer to present day levels, and the large variations in the record would be "ironed out" to show a fairly smooth variation. The Vostok record shows anything but that!
http://cdiac.ornl.gov/trends/co2/graphics/vostok.co2.gif

Diffusion can ONLY move material from high concentration to low concentration regions -- 2nd law of thermodynamics. The mechanism of diffusion makes no difference to this, in exactly the same way that scientists can and will rule out perpetual motion machines without looking too closely at the detail of the ingenious mechanisms they are based on.
 

Offline Peter Ridley under another name

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« Reply #30 on: 03/06/2011 10:34:40 »
Hello Dr. Christie Ive had a first read of “Carbon Dioxide Separation through Polymeric Membrane Systems for Flue Gas Applications” http://www.benthamscience.com/cheng/samples/cheng%201-1/Sandra%20E.%20Kentish.pdf and was puzzled straight away by the start saying
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A developing technology is membrane gas separation, which is more compact, energy efficient and possibly more economical than mature technologies, such as solvent absorption
Is a polymeric membrane like a latex balloon? If it is it seems to say that its not a solvent like water and the CO2 doesn’t dissolve in it so does it dissolve in latex?

The paper talks about molecules adsorbing (I hadn’t heard of that word before) along the pore walls and surface diffusion, not about dissolving in the membrane and that is interesting because Pete Ridley also asked about adsorption. On 28th February at 20:50 he talked about Professor Hartmut Frank saying this happened in the snow as it was falling. He asked Bored chemist
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whether or not that initial adsorption of CO2 in the snow is a chemical or a physical process (http://www.tutorvista.com/content/chemistry/chemistry-iv/surface-chemistry/absorption-types.php). My suspicion is that it is Chemisorption but as I’m not a chemist I’d appreciate your opinion. Following on from that is another question about adsorption in the deep firn, but that can be followed up later. Let’s work our way down the ice sheet looking at the different processes that Professor Zbiniew Jaworowski has been expressing concern about since 1992 and return to deep firn adsorption of CO2 and clathrate formation at a later stage
http://www.thenakedscientists.com/forum/index.php?topic=38675.50.

Bored chemist never had a chance to answer that question of Pete Ridley’s about adsorption because the thread was locked. Can you tell me what the answer is please and can you tell me if adsorption occurs in ice not just in snow. I googled adsorption and it says
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The accumulation of gases, liquids, or solutes on the surface of a solid or liquid
with a diagram of gas molecules sticking onto charcoal. If CO2 gets adsorbed does it stick to the ice and how thick does it get and does it block up pores and channels or does it go somewhere?

Another thing that paper talks about kinetic diameter like Pete Ridley did. It gives a list of kinetic diameters for N2 O2 CH4 and CO2 in table1 which are nearly like he said on 14th April at 21:38 http://www.thenakedscientists.com/forum/index.php?topic=38675.0.

I’ll have to read the paper again a few times to try to understand more what is being said because its hard for me to understand but I'll keep trying.
 

Offline graham.d

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« Reply #31 on: 03/06/2011 13:55:07 »
Hi Yelder. I have not read all the posts but it is interesting to see experiments like this being done in a home/kitchen environment. A couple of suggestions to improve the results validity:

1. Use something with better quality control than party balloons. Condoms may be better if rather more expensive.
2. Use several balloons for each single test to minimise the variability of the quality of the balloon and/or method of sealing (knot??) from the experiment.

 

Offline damocles

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« Reply #32 on: 03/06/2011 15:56:16 »
Hello Dr. Christie Ive had a first read of “Carbon Dioxide Separation through Polymeric Membrane Systems for Flue Gas Applications” http://www.benthamscience.com/cheng/samples/cheng%201-1/Sandra%20E.%20Kentish.pdf and was puzzled straight away by the start saying
Quote
A developing technology is membrane gas separation, which is more compact, energy efficient and possibly more economical than mature technologies, such as solvent absorption
Is a polymeric membrane like a latex balloon? If it is it seems to say that its not a solvent like water and the CO2 doesn’t dissolve in it so does it dissolve in latex?

Yes. A latex balloon is acting as a polymeric membrane and selectively passing CO2 in this situation. And the CO2 is definitely dissolving in the latex. It is because it is more latex-soluble than the other gases that CO2 effuses more quickly. Solvent extraction as a  "conventional technology" is quite a different process, involving use of a liquid solvent to selectively remove the gas, followed (if required) by releasing the gas from the liquid again. Physical means like low pressure or warming might be used for this part of the process, or chemical means via reaction. With membrane permeation technology, the required gas dissolves in the membrane, as it would in a liquid solvent, but then it is spontaneously released at the other side of the membrane where there is none of the gas initially present. So the membrane is effectively holding the other gases in and allowing the required gas to escape. The whole situation is governed by the principles of chemical equilibrium-- thoroughly covered in any college freshman course or textbook. Membrane permeation can only separate, never concentrate -- the gas on the extraction side of the membrane arrives at a lower concentration or partial pressure than that in the original sample.

Yelder again:
Quote
Bored chemist you said that the formula for pure latex of C3H3N
Quote
is just plain wrong
so can you say what it really is?.

Bored Chemist was quite right about it being the formula of nitrile rubber. Acrylonitrile is CH2=CH-C≡N which is C3H3N. So PAN is {-CH2-CH(CN)-}n , or (C3H3N)n

Latex is {-CH2-C(CH3)=CH-CH2-}n , or (C5H8)n . The lower case n indicates an n-fold repetition, and is nothing to do with the element nitrogen. This sort of thing gives plenty of scope for confusion! There is definitely no nitrogen bonded into a latex polymer.
« Last Edit: 03/06/2011 15:58:28 by damocles »
 

Offline Peter Ridley under another name

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« Reply #33 on: 03/06/2011 18:48:45 »
Hello graham.d I was going to get some condoms but then came across those people saying about their bike tyres gong down when CO2 was used but staying up with air so is an experiment needed now to show that it happens. I might get some tyres instead and a bottle of CO2 that they seem to be able to get easily if I want to do it. I’m not sure I need to bother now that Dr Christie is helping on this as he seems to know all about it.

Hello Dr.Christie, thanks for getting back so quickly again. The help that you give is like what Professor Wolff did on the “Another Hockey Stick Illusion?” but more theory like you said you are and he was using the empirical evidence for ice cores. OK so CO2 dissolves in latex and in a polymeric membrane but now you say that it effuses, not diffuses. When I googled effuse I found this “Graham's Law of Effusion” U-tube lesson that says
Quote
The rapid and random motion of tiny gas molecules results in effusion, the escape of gas molecules through very small openings
http://www.youtube.com/watch?v=TropqfFqUiI&feature=related and the teacher talks about helium in a balloon and why it goes down
Quote
you’ve got it enclosed in a container. Its enclosed in a good balloon usually. Well the holes that it is escaping through may only be about the size of the atoms or molecules that are escaping so the helium can very gradually effuse through
She goes on to say that gases can effuse through bottles. So does that mean that effusion is the same as diffusion but just means going through tiny openings instead of in a big space?

Thanks again for helping because I expect your very busy marking exams or something. That paper you linked to gives a lot of information about the separation of gases from a mixture using a membrane and is a big help but it doesn’t talk about effusion so is it just a matter of people using the words differently. When you say that
Quote
the CO2 is .. dissolving in the latex ..  effuses more quickly .. but then it is spontaneously released at the other side of the membrane
would someone else say it effuses more quickly through it? I’m still puzzled about that word dissolve so Ill give an example of what I didn’t think was dissolve. A sponge has lots of little holes and water can go into those holes so there is a mixture of a liquid in a porous flexible solid but is the water dissolved in the sponge? I didn’t think so. Whats the difference between a very thin sponge and a latex or polymeric membrane?
 

Offline damocles

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« Reply #34 on: 04/06/2011 00:29:44 »
Yelder, a response to a couple of points in your latest.

Effusion and diffusion? It is all a matter of Latin prefixes. E(f)-fusion is out of -melting, and di(f)-fusion is through-melting. So diffusion refers to something moving through a matrix of some sort, and effusion refers to something moving out of a container. They are really the same process (or set of processes). But to say "diffusion through" or "effusion out of" is a tautology (redundancy), while to say "diffusion out of" or "effusion through" may be valid, but is more likely a mild oxymoron (contradiction).

Solutions and mixtures and holes in sponges and the like? The word dissolve relates very directly to solutions and the process of entering into a solution. These are very basic concepts in Chemistry, and probably should be discussed a little more and in more depth in chemistry subjects at secondary and tertiary level. The key concept is a matter of homogeneous or heterogeneous. In a true solution, the component substances are divided at molecular level, and any sample of about 1000 molecules or more should have the same molecular make-up with only statistical variation. In a heterogeneous mixture the divisions are "lumpy" with clumps of many molecules of each of the component substances. There is also a very important intermediate grey area with mixtures known as colloids, where the components come in lumps of size about 1 nm to 1 μm (one millionth to one thousandth of a millimetre). Bigger than single molecules, but not much bigger! Colloids have some interesting and surprising properties. Thirty or forty years ago colloid chemistry was a bit of a backwater specialization. More recently it has formed much of the basis of the modern and trendy field known as nanotechnology.

And I am not really busy marking exam papers and the like; I am enjoying a very relaxed retirement. I maintain an Honorary appointment to my Department for the small amount of professional work I might get around to doing!
 

Offline Bored chemist

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« Reply #35 on: 04/06/2011 14:26:31 »
Effusion is the word usually used to describe a gas escaping through a small hole- for example a pinhole in a piece of metal foil.
Diffusion is the transfer of a material through the bulk of another material.
I can calculate effusion rates directly from the kinetic theory of gases (though I'd not like to have to- it's been a while since I studied that).
Diffusion rates are measured empirically because they depend on a lot of odd parameters. The exception is the diffusion of one gas through another (for example when you smell a gas leak)  which you can calculate, and even that case is fairly complicated.
 

Offline Peter Ridley under another name

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« Reply #36 on: 06/06/2011 11:49:06 »
Dr. Christie thanks for helping me on what diffusion is which I now think I understand better but not all except the bit about melting but I guess that is just the Latin and I neednt worry about it. You said
Quote
So diffusion refers to something moving through a matrix of some sort, and effusion refers to something moving out of a container
Thinking about that balloon or tyre isnt the rubber a “matrix of some sort” so is the He or CO2 doing effusion and diffusion at the same time?

I remember on the “Another Hockey Stick Illusion?” http://www.thenakedscientists.com/forum/index.php?topic=38675.25 on 19th April 04:02) yor_on quoted from “Carbon dioxide concentrations for the Last Millennium, Antarctica” http://doi.pangaea.de/10.1594/PANGAEA.728135 about
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diffusion of dissolved air through the ice matrix into the bubbles
then Pete Ridley said on 28th April at 20:50 what Professor Hartmut Frank said about
Quote
preferred diffusion of CO2 into the ice matrix
http://www.thenakedscientists.com/forum/index.php?topic=38675.50. Then Bored Chemist said here on 31st May at 09:46
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the gases .. can "dissolve" in the rubber, diffuse through it, and escape. Secondly the air outside a balloon full of CO2 will diffuse into the balloon .. so the balloon is filling up as well as emptying
http://www.thenakedscientists.com/forum/index.php?topic=39542.0.

You linked to a paper in your first comment here and it says in section 2.2 about
Quote
The molecular sieve framework forms a well-defined repeating structure of regular channels and cages. Gas separation is dependent on the size of these channels and cages relative to the kinetic diameter of the gas. The difference in kinetic diameter of gas molecules (Table 1) dictates which molecular sieves are useful and provides an indication of selectivity [17]. For example, Zeolite 3A separates hydrogen effectively from hydrocarbon feeds because the pore diameters are ~3 Å [109]. Zeolite 4A has pore sizes of ~ 4 Å, which will separate carbon dioxide from nitrogen and methane
http://www.benthamscience.com/cheng/samples/cheng%201-1/Sandra%20E.%20Kentish.pdf. It also shows a picture in fig (6) of what happens.

I see the “porous hollow fibre” like a container and the wall like the membrane of a balloon or tyre with a “repeating structure of regular channels and cages” to be a matrix so does that mean that the hydrogen and carbon dioxide are dissolved into the membrane then diffuse through it and effuse out of it? Like you said
Quote
They are really the same process (or set of processes)

On that business about what was right to use kinetic or collision diameter am I right to take what Pete Ridley said that it is kinetic diameter when those “regular channels” are around the size of the molecules “~3 Å” and “~ 4 Å”? I’d like to be able to clear that one up before talking about the other things in that paper “Carbon Dioxide Separation through Polymeric Membrane Systems” like the different ways to separate gases. It says
Quote
There are five possible mechanisms for membrane separation .. Knudson diffusion, molecular sieving, solution-diffusion separation, surface diffusion and capillary condensation .. Molecular sieving and solution diffusion are the main mechanisms for nearly all gas separating membranes. Knudson separation is based on gas molecules passing through membrane pores small enough to prevent bulk diffusion ..

 
You’ve said a little bit about Knudsen diffusion and molecular sieving but I think Ill have more questions if you have time to keep on helping me.
 

Offline Peter Ridley under another name

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« Reply #37 on: 06/06/2011 22:04:57 »
Hello again Dr. Christie, on this thing about CO2 inside a balloon dissolving into the latex then diffusing then effusing into the air I had another read of your answer to “Why is my carbon dioxide effusing too fast?” http://www.madsci.org/posts/archives/may98/895552329.Ch.r.html and see you said then that
Quote
'The permeation of small molecules through flawless polymer films occurs by the consecutive steps of solution of permeant in the polymer and diffusion of the dissolved permeant.' In the table for Natural rubber which follows (page III-233), the following permeabilities are given: oxygen 23.3, argon 22.8, nitrogen 9.43, carbon dioxide 153. Permeability is governed by solubility and diffusion. There is little difference in the respective diffusion coefficients: 1.73, 1.36, 1.17, and 1.25 for the four gases (note that diffusion coefficients through the polymer do not reflect either molecular size or molar mass directly). The striking difference in the permeability figure for carbon dioxide is associated with solubility in the rubber: heat of solution figures are -4.2 kJ/mol for oxygen, -0.1 for argon, +2.1 for nitrogen, but -12.5 for carbon dioxide

That seems to answer part of what I asked in my last comment about 
Quote
so does that mean that the hydrogen and carbon dioxide are dissolved into the membrane then diffuse through it and effuse out of it?
except for the effuse bit. I see that CO2 permeability is 6 times for O2 and Ar and 15 times N2 so does the same thing happen  in ice? Am I right thinking that the – “heat of solution” figures for O2 Ar and CO2 mean that heat is generated not used http://www.google.co.uk/search?q=define+%22heat+of+solution%22&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a#hl=en&client=firefox-a&hs=rU1&rls=org.mozilla:en-GB:official&q=Heat+of+solution&tbs=dfn:1&tbo=u&sa=X&ei=BDHtTdD0Cc_C8QPDtJTDAQ&ved=0CBgQkQ4&bav=on.2,or.r_gc.r_pw.&fp=11e1338e32ed5bc&biw=1024&bih=535? If it is could that make ice melt a bit?

I googled - permeability CO2 ice – and found a 1958 paper “Permeation of Gases through Ice” http://onlinelibrary.wiley.com/doi/10.1111/j.2153-3490.1959.tb00041.x/pdf that said
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One may think of two possible pathways for the permeation of gas through ice, either through pores in a dry crystalline ice structure, or through a liquid phase which might exist in the ice. In the first case, according to Graham's law, one would expect that the smaller oxygen molecules would move through the ice in greater amount than the carbon dioxide molecules, but if permeation takes place through liquid pathways carbon dioxide would pass through in greater amount because of its 20 -30 times greater solubility. The latter was clearly the case, and this strongly suggests that we are dealing with permeation through a liquid phase
I see that he says
Quote
the smaller oxygen .. than the carbon dioxide molecules
then says that is why CO2 is more permeable because of liquid being there. If kinetic diameter should be used for the permeation would there need to be liquid for CO2 to permeate more easily and if liquid is there would the CO2 permeate even more easily and would it make more liquid because of “heat of solution” do you think? 
 

Offline damocles

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« Reply #38 on: 07/06/2011 10:01:41 »
Just a quick comment on a couple of points from Yelder's latest:
Quote
Am I right thinking that the – “heat of solution” figures for O2 Ar and CO2 mean that heat is generated not used
This is quite right. However the heat is associated with entering into solution or leaving solution. If a gas is dissolving into a membrane, there will be a minute heating of the entry side and a minute cooling of a little under the same size at the exit side.
A brief technical lesson: The solubility of a material is governed by the "standard free energy of solution". This has two components, one of which is the "heat of solution" or "standard enthalpy of solution" that I quoted. The other is an entropy based term. For solid in liquid solutions, this can vary a lot.  But it is usually a large positive entropy, as the relatively ordered structure of a solid is broken down into a less ordered random distribution in a liquid solvent. But for solutions of gases it is a small negative entropy that varies little for different gases or different solvents. Gases are slightly less disordered in solutions than as the free gas because their motions are somewhat restricted. So my reason for quoting "heats of solution" was because it gives a strong indication of the affinity of the gas for the matrix, and of the consequent solubility. It was not really anything to do with heat as such.

Quote
I googled - permeability CO2 ice – and found a 1958 paper “Permeation of Gases through Ice” http://onlinelibrary.wiley.com/doi/10.1111/j.2153-3490.1959.tb00041.x/pdf that said
Quote
One may think of two possible pathways for the permeation of gas through ice, either through pores in a dry crystalline ice structure, or through a liquid phase which might exist in the ice. In the first case, according to Graham's law, one would expect that the smaller oxygen molecules would move through the ice in greater amount than the carbon dioxide molecules, but if permeation takes place through liquid pathways carbon dioxide would pass through in greater amount because of its 20 -30 times greater solubility. The latter was clearly the case, and this strongly suggests that we are dealing with permeation through a liquid phase
I see that he says
Quote
the smaller oxygen .. than the carbon dioxide molecules
then says that is why CO2 is more permeable because of liquid being there. If kinetic diameter should be used for the permeation would there need to be liquid for CO2 to permeate more easily and if liquid is there would the CO2 permeate even more easily and would it make more liquid because of “heat of solution” do you think? 
It is important to understand the context of this paper. It is written by a biologist whose reason for pursuing this enquiry has to do with the survival of plants through the Canadian winter. He is actually doing the experimental work at temperatures that are not extreme -- just a few degrees below freezing.
You have been contending that kinetic diameter of CO2 is smaller than that of O2 or N2, and that kinetic diameter rather than collision diameter should be used in these diffusion studies. If you are right, then his conclusion (that liquid brine channels must be an important factor) is invalidated.

Quote
If kinetic diameter should be used for the permeation would there need to be liquid for CO2 to permeate more easily and if liquid is there would the CO2 permeate even more easily and would it make more liquid because of “heat of solution” do you think?
(Hope it is not bad form to re-quote) Let us get the logic of this into place. He has MEASURED diffusion rates, and INFERRED that liquid channels must be involved to explain why CO2 diffuses faster than O2. If you are right and he is wrong about the diffusion treatment in the absence of liquid channels, then that undermines his INFERENCE but has absolutely no effect on his MEASUREMENTS. There is no question of CO2 permeating even more easily, and as explained above, release of "heat of solution" in this context is not enough to melt anything.

His study makes some other telling points:
-- that the rate of diffusion of all three gases is more than a million times slower in ice than in water,
-- that diffusion rates fall off rapidly with decreasing temperature (though he only explores temperatures relatively close to melting point, so this trend might not continue).
 

Offline Peter Ridley under another name

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« Reply #39 on: 08/06/2011 11:33:08 »
Hi Bored chemist, in your last comment you said
Quote
Effusion is the word usually used to describe a gas escaping through a small hole- for example a pinhole in a piece of metal foil
I think that one of the difficulties that many of us lay people have is the different way that people, even scientists, use the terminology. Elsewhere effusion is described as you did but with the rider “into a vacuum” (although one source said “Effusion is the escape of a gas through a small hole into a vacuum or area of lower pressure”). Pete Ridley gave a link http://www.thenakedscientists.com/forum/index.php?topic=38675.0 14th April at 09:36) to an animation http://www.youtube.com/watch?v=0uBK7VxT00E that does that and describes how to
Quote
calculate effusion rates directly from the kinetic theory of gases
so it might help jog your memory.

Pete Ridley went on to say
Quote
but imagine that the bubble is an air pocket in an ice sheet approaching close-off, with all excepting one pore closed to all molecules (CO2 included). Imagine also that the hole size of that single pore is just larger than 0.33nm (the kinetic diameter of CO2) and that the red balls are CO2 molecules (N2, O2 and CH4 molecules present but not shown because they can’t escape but are still bouncing around inside in far larger quantities than CO2). Also imagine that the pore is not giving access to an empty space as shown but access to an equally small channel linking to another similar air pocket in a chain of such air pockets. Does that very simplified picture of the structure within the ice/firn help to clarify the basis of my main question? Does that very simplified picture of the structure within the firn/ice help to clarify the basis of my main question?
.

I see that you didn’t offer any help about this on that thread which is a shame because he needed it. Let’s hope that he’s watching this one and learning from it like I am.

Dr Christie’s explanation on 4th June at 00:29, involving going back to the Latin origin then talking about
Quote
The key concept is a matter of homogeneous or heterogeneous. In a true solution, the component substances are divided at molecular level
has helped me understand this a lot better but perhaps not fully. My understanding of the terms dissolve, diffuse and effuse were much too restricted. What I now understand the different terms to mean are:
- “to dissolve” is to form a homogenous mixture of several different substances,
- “to diffuse” is to move within (a vacuum, a fluid, a solid),
- “to effuse” is to move out of (a vacuum, a fluid, a solid),
(is another term “to infuse”, meaning to move into (a vacuum, a fluid, a solid) is required?)
In the context of this discussion we are specifically talking about individual molecules.

You said
Quote
Diffusion is the transfer of a material through the bulk of another material
and I see the significant word there being “bulk”. Dr. Christie said
Quote
diffusion refers to something moving through a matrix of some sort
and that puzzles me. From the definitions that I use above water going into a sponge and being squeezed out again is not dissolving (infusion?), diffusion and effusion because the substance of the sponge is not present as free molecules. Both water and sponge are “material” (per your definition of diffusion), the water is “something” and the sponge is “ a matrix of some sort” (per Dr. Christie’s definition). Despite that I do not think that water that has entered, permeated and been squeezed from a sponge has dissolved (infused?) diffused and effused because it does not form a homogenous mixture at the MOLECULAR level.

If my understanding is flawed again then please put me straight.

If I understand correctly then can you explain the difference between a balloon that has been punctured with numerous tiny holes (let’s say 10nm diameter each) and one that naturally has numerous tiny pores (let's say 0.33nm) as a result of being blown up and the latex stretched? Michegan State University Chemistry Department provides a spacefill model (which you can zoom into) of the molecular structure of latex [urlhttp://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/lipidstr2.htm#rubber/url]. This tells me that there are tiny air spaces between the fabric (a matrix of C and H atoms? With no mention of anything else, like water) which must grow larger as the fabric is stretched (as in blowing up a balloon). At some stage the spaces must become large enough to let through any trapped gas inside, like He or CO2. Is that what you and Dr. Christie are referring to as dissolving, diffusing and effusing into the outside air? If so, what is the appropriate measure of the gas molecules size when the air holes in the fabric are large enough for them to escape?

When I googled –effusion "into a vacuum" video – I came across “Chemistry: Effusion and Diffusion” http://thinkwell.mindbites.com/lesson/4721-chemistry-effusion-and-diffusion, part of a series of Chemistry course lectures taught by Professors Harman, Yee, and Sammakia available from Thinkwell, Inc. http://www.thinkwell.com/student/product/chemistry. The scientist presenting the lecture starts off talking about effusion being gases moving through a pin hole into an evacuated space and Graham’s Law. I was getting all excited – then it stopped and asked for $2.97 to see the rest.

You also said
Quote
Diffusion rates are measured empirically because they depend on a lot of odd parameters. The exception is the diffusion of one gas through another .. which you can calculate, and even that case is fairly complicated
Dr. Christie agrees with you about the complexity of this subject and as Professor Wolff said on "Another Hockey Stick Illusion?" about the processes in the deep firn of an ice sheet
Quote
I think that none of us has a definite molecular-level understanding of the physical process occurring at closeoff, and it would be great if someone can do the experiments in the lab to understand that better.  But it won't alter the empirical facts[/quote http://www.thenakedscientists.com/forum/index.php?topic=38675.75.
 

Offline Peter Ridley under another name

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« Reply #40 on: 14/06/2011 19:13:21 »
Dr. Christie E-mailed today that he
Quote
Tried to post the following on the discussion forum, but the posting failed with an unspecified error, so I am sending it to you here
so I'll post his response to my previous comment on his behalf.
 
------
Hi Yelder
Quote
If my understanding is flawed again then please put me straight.
 
If I understand correctly then can you explain the difference between a balloon that has been punctured with numerous tiny holes (let’s say 10nm diameter each) and one that naturally has numerous tiny pores (let's say 0.33nm) as a result of being blown up and the latex stretched? Michegan State University Chemistry Department provides a spacefill model (which you can zoom into) of the molecular structure of latex [urlhttp://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/lipidstr2.htm#rubber/url]. This tells me that there are tiny air spaces between the fabric (a matrix of C and H atoms? With no mention of anything else, like water) which must grow larger as the fabric is stretched (as in blowing up a balloon). At some stage the spaces must become large enough to let through any trapped gas inside, like He or CO2.

 
I will have a try.
 
Firstly, the space-filling model of molecular structure shown in Prof Reusch's website is intended to show how the polymer molecules are put together in terms of the relationships and bonding of individual atoms in the molecular chain. What the model shows is the structure of a small section of an individual chain. It repeats at the purple atoms, and a single molecule of latex would typically contain between about 1000 and 10000 of these repetitions, and they do not run in a straight line.
 
Secondly this one molecule is fairly tightly packed in laterally with parts of chains of other molecules. In a polymer of this sort the packing cannot be perfect; there are always holes. But these are randomly sized and shaped sealed cells, not open channels (unless the rubber is perished or damaged).
 
Thirdly, there is no way that the tiny gaps you see are "air spaces". Any of the molecules in air are about the size of two of the dark grey carbon atoms, and there is no way that they would fit in the tiny gaps you are seeing in the model.
 
Fourthly, when you stretch rubber, you are not producing a regular expansion of the molecular structure. You are not stretching the chemical bonds between atoms nor even opening out the bond angles from their natural 110-120 degrees closer to a 180 degree straight line. Rather, you are actually partly unravelling a tangled series of random chain coils into a more extended chain -- a lot like trying to pull a tangle of ropes apart. Surprisingly, even some chemists in the rubber industry are not aware of this!
 
If you would really like to find out about how polymers work -- rubbery polymers, glassy polymers, and crystalline polymers -- I thoroughly recommend a book (a little old by now, like me) by Leo Mandelkern: "An Introduction to Macromolecules". It is an accessible and e-n-j-o-y-able read even for an intelligent layman.

-----------

Dr. Christie, thanks very much for another very helpful comment.

PS: I see that the problem was the spam detector picking up on the word "e-n-j-o-y-able" minus the -.
« Last Edit: 14/06/2011 19:15:18 by Yelder »
 

Offline rosy

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« Reply #41 on: 15/06/2011 10:21:22 »
Argh. Am getting very fed up of this spam filter. Have now added enjoyable to enjoy, enjoyed and enjoyment on the whitelist!
 

Offline Peter Ridley under another name

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« Reply #42 on: 15/06/2011 19:07:02 »
Hi Rosy, yes, it can be a little frustrating at times, can't it, especially because it does not make it clear to a newcomer what the problem is.
 

Offline Peter Ridley under another name

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« Reply #43 on: 20/06/2011 19:10:42 »
On 31/05/2011 10:21:16 I reported on my repeat of the balloon experiment that I started on 29th May where I had two balloons again, one filled with air and the other being half CO2 and half air. My comment after two days in which both balloons stayed the same size, was
Quote
If the CO2 was going into the balloon like you said then the one with half CO2 should have gone down a bit by now
After 17 days the situation was no different and I was tempted to terminate it, guessing that the reason might be that the balloons were coloured (not natural as on previous tests) and perhaps the die/colouring reduced the size of pores in the latex or was preventing the CO2 dissolving.

I was about to terminate the experiment because my wife had complained about the tape measure I’d stuck to the floor to get the balloon diameter when I noticed that the CO2 balloon looked a lot smaller than the other and sure enough it has suddenly started to deflate. It was down to 350mm and half an hour later it was at 300mm v the original 440mm while the air one is at 420mm v 450mm. I tested the CO2 balloon in waterwhen it was at 300mm and saw no bubbles escaping through any leak but an hour later it is down to 230mm but still no sign of a leak when immersed in water.

Have any of the experts here any idea why there would be that delayed response and what is causing this sudden collapse? - Dr. Christie, please help.

Regarding Dr. Christie’s response of 14th June @ 19:13 it looks as though the preferential escape of CO2 v other atmospheric gases from a latex enclosure may be a different process to that covering the escape of CO2 from air pockets in ice. On the other hand, Dr. Zbiniew Jaworowski has discussed in several of his numerous papers how liquid water exists in deep ice. I propose to take a look at his ideas again and comment on them in the hopes of getting some further assistance here on that .

I’ll first have a look at an article that I hadn’t come across until now “Doing Jaworowski justice” (http://www.greenworldtrust.org.uk/Forum/phpBB2/viewtopic.php?t=116&sid=502c043eca9509535498780bbd11b74f) because the exchanges between Ferdinand Engelbeen and Lucy Skywalker are it is along the same lines as Pete Ridley’s exchanges with others on “Another Hockey Stick Illusion?” (http://www.thenakedscientists.com/forum/index.php?topic=38675.0).

Talking about Lucy Skywalker (anyone have any information about her?) she posted an interesting guest post “Yamal treering proxy temperature reconstructions don’t match local thermometer records” (http://wattsupwiththat.com/2009/10/30/yamal-treering-proxy-temperature-reconstructions-dont-match-local-thermometer-records/) relating to Michal Mann’s original “hockey stick”.



As Lucy concluded “There is no sign whasoever of a Hockey Stick shape with serious uptick in the twentieth century, in the thermometer records. Yet these records are clearly very consistent with each other, no matter how long the record or how cold, high, or maritime the locality, with a distance span of over a thousand miles. Neither does the Hockey Stick consistently show in the treerings except in the case of a single tree. Even with thermometer records that are incomplete and suffering other problems, the “robust” conclusion is -
“Warmist” treering proxy temperature evidence is falsified directly by local thermometer records”.
« Last Edit: 20/06/2011 19:13:41 by Yelder »
 

Offline damocles

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« Reply #44 on: 20/06/2011 21:16:56 »
On 31/05/2011 10:21:16 I reported on my repeat of the balloon experiment that I started on 29th May where I had two balloons again, one filled with air and the other being half CO2 and half air. My comment after two days in which both balloons stayed the same size, was
Quote
If the CO2 was going into the balloon like you said then the one with half CO2 should have gone down a bit by now
After 17 days the situation was no different and I was tempted to terminate it, guessing that the reason might be that the balloons were coloured (not natural as on previous tests) and perhaps the die/colouring reduced the size of pores in the latex or was preventing the CO2 dissolving.

I was about to terminate the experiment because my wife had complained about the tape measure I’d stuck to the floor to get the balloon diameter when I noticed that the CO2 balloon looked a lot smaller than the other and sure enough it has suddenly started to deflate. It was down to 350mm and half an hour later it was at 300mm v the original 440mm while the air one is at 420mm v 450mm. I tested the CO2 balloon in waterwhen it was at 300mm and saw no bubbles escaping through any leak but an hour later it is down to 230mm but still no sign of a leak when immersed in water.

Have any of the experts here any idea why there would be that delayed response and what is causing this sudden collapse? - Dr. Christie, please help.

I suspect that the "delayed response" is an illusion:
(1) Balloon latex does not follow Hooke's law. It is very stretchy at low pressures (low Young's modulus is the technical term) but much less so at higher pressures, almost rigid. What I think you might be seeing is a steady reduction in pressure in the CO2 balloon, but no discernible change in diameter while it remained effectively fully inflated.
(2) This effect is compounded with the fact that a reduction in volume of gas contained in a balloon is not commensurate with an equivalent change in diameter. If you observed a halved diameter, then the volume is only one eighth of what it was.

Quote
Regarding Dr. Christie’s response of 14th June @ 19:13 it looks as though the preferential escape of CO2 v other atmospheric gases from a latex enclosure may be a different process to that covering the escape of CO2 from air pockets in ice. On the other hand, Dr. Zbiniew Jaworowski has discussed in several of his numerous papers how liquid water exists in deep ice. I propose to take a look at his ideas again and comment on them in the hopes of getting some further assistance here on that .

There is no significant escape of CO2 from deep ice levels. If you look at the Vostok results, you will see that there is significant quite sharply resolved structure in the CO2 profile for a few hundred thousand years


There are peaks and valleys, with concentrations ranging from about 190 to 290 ppm. If CO2 had migrated through the ice, structure like this would necessarily be wiped out.
 

Offline Peter Ridley under another name

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« Reply #45 on: 21/06/2011 10:22:44 »
Hi John (damocles) thanks for having a stab at explaining that sudden collapse of the balloon with ½ CO2 and ½ air. It’s now down to 200mm diameter from the original 440mm while the air-filled one remains at 430mm (down from 450mm). Perhaps it is worth mentioning that the original (uncoloured) balloon that I filled with air about a month ago is still fully inflated. Hi John (damocles) thanks for having a stab at explaining that sudden collapse of the balloon with ½ CO2 and ½ air. It’s now down to 200mm diameter from the original 440mm while the air-filled one remains at 430mm (down from 450mm). Perhaps it is worth mentioning that the original (uncoloured) balloon that I filled with air about a month ago is still fully inflated.

I propose to re-use those same balloons but swop around the CO2 and air to try to rule out a difference in each balloon’s properties.



Regarding your response to my comment about Jaworowski discussing liquid water in deep ice, I misled you on that. I should have said water in deep firn. In his 1997 paper “ANOTHER GLOBAL WARMING FRAUD EXPOSED Ice Core Data Show No Carbon Dioxide Increase”  (http://www.warwickhughes.com/icecore/IceCoreSprg97.pdf) Fig. 2 Jaworoski provided an illustration of the vertical structure of an ice sheet and says
Quote
.. meltwater seeps down and collect over impermeable layers. The firn density gradually increases with depth and at .83 g/cm3, firn changes into solid ice in which all pores are occluded, forming the primary air bubbles. Between a depth of 900 to 1,200m air bubbles disappear. Liquid water is contained in quasi-infinite network of capillary veins and films between the ice crystals. ..

He goes on to talk extensively about liquid water in the ice, e.g.
Quote
.. liquid water is present in ice even at very low temperatures, and because many chemical and physical processes occur, in situ, in ice sheets and in recovered ice cores. These factors, discussed in References 8, 12, 22, and 24-28, change the original composition of air entrapped in ice, making the ice core results unrepresentative of the original chemical composition of the ancient atmosphere ..

He says in
Quote
.. Some False Assumptions - For climatic interpretation of the ice core data the following assumptions are used:
.. (2) No liquid phase occurs in firn and ice at average annual air temperatures of 224°C or less ..
these assumptions are incorrect, and thus that the conclusions on low pre-industrial levels of atmospheric greenhouse gases are wrong .

Professor Eric Wolff said on Pete Ridley’s “Another Hickey Stick Illusion?” thread
Quote
I think that none of us has a definite molecular level understanding of the physical process occurring at close-off ..
(http://www.thenakedscientists.com/forum/index.php?topic=38675.msg354373#msg354373). If we can for the moment make the assumption that Jaworowski is correct about that water in firn (and there are plenty who say that he is wrong) what effect do you think that would have on the movement of CO2 within the firn and ice?
 

Offline damocles

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« Reply #46 on: 21/06/2011 11:12:19 »
From Yelder's latest:
Quote
Professor Eric Wolff said on Pete Ridley’s “Another Hickey Stick Illusion?” thread
Quote
I think that none of us has a definite molecular level understanding of the physical process occurring at close-off ..
(http://www.thenakedscientists.com/forum/index.php?topic=38675.msg354373#msg354373). If we can for the moment make the assumption that Jaworowski is correct about that water in firn (and there are plenty who say that he is wrong) what effect do you think that would have on the movement of CO2 within the firn and ice?

Hmmm! I am intrigued with the idea of a Hickey Stick   ;D

This sort of post continues to miss the whole point of the evidence in the Vostok Ice core. To put it very simply:
-- Regardless of the detail of the mechanism a material (CO2 in this case) can only move from regions of higher concentration to lower concentration (else the second law of thermodynamics is violated and we can design a perpetual motion machine around the phenomenon)
-- The persistence of the sharp variations over periods of less than 1 kyr in the Vostok record is solid proof that the CO2 has NOT moved, because if it had moved, the only thing it could have done would be to have smoothed out these variations. The peaks would have had to flow into the troughs.
-- The detail of presence of liquid water or not, or fancy notions about diffusion mechanisms and bubble formation mechanisms and so on are therefore totally irrelevant. Jaworowski may or may not be right in the detail of some or all of what he has to say. It does not alter the fact that there is 100% solid proof in the ice record that the CO2 has moved less than 1 kyr through the profile in the whole lifetime of the ice sheet.
 

Offline Peter Ridley under another name

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« Reply #47 on: 21/06/2011 16:22:23 »
Hi John, thanks for the prompt response.

I’m surprised that you are
Quote
.. intrigued with the idea of a Hickey Stick ..
As I understand it this is what the global mean atmospheric CO2 content during the past 1000 years is claimed to be by the paleoclimatologists using measurements of air “trapped” in ice.

(http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/Image18.gif)
It looks very similar to the hockey stick claimed to be a true representation of the mean atmospheric temperature anomaly during the past 1000 years by Michael Mann

<spam link removed>


I’m sorry that I continue
Quote
to miss the whole point of the evidence in the Vostok Ice core
and of lots of other ice cores


(http://www.ferdinand-engelbeen.be/klimaat/klim_img/antarctic_cores_800kyr.jpg) but even though I accept that CO2
Quote
.. can only move from regions of higher concentration to lower concentration ..
wouldn’t those persistent
Quote
.. sharp variations over periods of less than 1 kyr in the Vostok record ..
still exist if the original CO2 concentration was much much higher than the level shown in the ice core record if the rate of migration was very very slow? Could not a slow rate of migration still leave residual peaks and troughs as seen from that record? Could this then mean that
Quote
.. The detail of presence of liquid water or not, or fancy notions about diffusion mechanisms and bubble formation mechanisms and so on ..
would be totally relevant?

Under those circumstance could not the claim that
Quote
.. that there is 100% solid proof in the ice record that the CO2 has moved less than 1 kyr through the profile in the whole lifetime of the ice sheet ..
be more opinion than fact?

Of course, not being a scientist I could be totally wrong, but Jaworowski and his supporter Professor Hartmut Frank are scientists, the latter being highly regarded by his peers. As Pete Ridley said almost a year ago
Quote
Dr. Hartmut Frank (Professor of Chemistry and Ecotoxicology, University of Bayreuth, Germany) who wrote the forward to Jaworowski’s 1994 paper, says QUOTE:
.. Prof. Jaworowski's main argument is valid and will remain valid because it is based on simple, but hard physicochemical facts. Most of the facts can be found in the old, traditional "Gmelin's Handbook of Inorganic Chemistry” - but nobody reads such books anymore today. The facts are so basic that one cannot even start a research project on an investigation of the validity of such carbon dioxide analyses in ice cores because the referees would judge it too trivial. But if one would apply proper quality assurance/quality control principles, as they are common in most other areas of application of chemical-analytical methods (for instance in drug control or toxicology) the whole building of climate change would collapse because of the overlooked fault.

And so one continues because there are so many living in or from this building. UNQUOTE
(http://julesandjames.blogspot.com/2010/07/monbiot-exonerated.html).
« Last Edit: 23/06/2011 13:45:27 by peppercorn »
 

Offline damocles

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« Reply #48 on: 21/06/2011 21:10:54 »
Quote
wouldn’t those persistent
Quote
.. sharp variations over periods of less than 1 kyr in the Vostok record ..
still exist if the original CO2 concentration was much much higher than the level shown in the ice core record if the rate of migration was very very slow? Could not a slow rate of migration still leave residual peaks and troughs as seen from that record?

No, they definitely could not still exist; those sharp features would necessarily be the first to disappear of there were any migration of CO2 at all.

It only involves a few kyr of migration through the record to wipe them out, one kyr to completely blunt them. CO2 trapped in ice has not moved.

Quote
Under those circumstance could not the claim that
Quote
.. that there is 100% solid proof in the ice record that the CO2 has moved less than 1 kyr through the profile in the whole lifetime of the ice sheet ..
be more opinion than fact?

No

Quote
Of course, not being a scientist I could be totally wrong, but Jaworowski and his supporter Professor Hartmut Frank are scientists, the latter being highly regarded by his peers.

No disrespect to Professor Hartmut Frank, but "Ecotoxicology" points to a background in Organic Chemistrry and Medical Chemistry, which is a very different specialization to Glaciology or Atmospheric Chemistry/Physics. It is disingenuous to trot out credentials like this when you are prepared to ignore the credentials of a huge consensus of Atmospheric Scientists who have views that do not fit in with your preconceived notions.

... And (unless I hear much more effective refutation), here endeth the topic as far as I am concerned.
 

Offline chris

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« Reply #49 on: 23/06/2011 00:53:20 »
Evidence has been presented to me confirming that the user "Pete Ridley" has, by his own admission, been using the false name "Yelder" to participate in this forum, referring to his own previous posts as though they were those of a third party; this is despite being asked previously to leave, and subseqently banned, owing to his repeated failure to abide by our forum rules and acceptable user policy.

Wantonly providing false personal information on the forum in this way is not acceptable.

For this reason, Mr Pete Ridley's alias "Yelder" has also been banned and renamed (for the benefit of other forum users) to make it clear that this content is also the work of Mr Pete Ridley.

Furthermore, having run its course and been thoroughly discussed, this thread has now been locked; thank you to everyone who has contributed to it.

Chris Smith
« Last Edit: 25/06/2011 00:07:55 by chris »
 

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