Pro teams and CO2

ben@31

bernithebiker wrote:

Oh and recently saw an article about a potential ban on using helium to fill balloons as it's becoming much rarer.

Rubbish.

You can't create or destroy helium. Just move it about. As soon as the balloon inevitably bursts the helium will return back to the atmosphere.

bernithebiker

ben@31 wrote:

bernithebiker wrote:

Oh and recently saw an article about a potential ban on using helium to fill balloons as it's becoming much rarer.

Rubbish.

You can't create or destroy helium. Just move it about. As soon as the balloon inevitably bursts the helium will return back to the atmosphere.

hey pal, don't shoot the messenger......this is from the Independent;


At the Oxford Centre for Human Brain Activity, we have had to temporarily shut down our cryogenic laboratory equipment.

Our multimillion-pound magnetoencephalography (MEG) facility must operate at temperatures of near-absolute-zero degrees Kelvin (-273C), but this month they will not be maintained due to yet another interruption in our helium supply – only liquid helium can cool to such extreme temperatures.

This is not the first time we have had to halt operations over the past 12 months, and we fear more difficulties over the coming year.

Despite the apparent abundance of helium as cheap gas for filling party balloons, industrial-grade liquid helium is a precious commodity, and it is increasingly difficult to secure supplies. Intermittent supplies are extremely disruptive to our research programme, and jeopardise the basic viability of the centre.

The US government is currently the largest helium supplier, but in recent years privatisation has led to a rapid sell-off of the National Helium Reserve. This fire-sale has distorted the helium market, causing turmoil in global supplies.

Like so many natural resources, it is inevitable that demand will out-strip supply. Although the time scale of effective helium depletion cannot be predicted with certainty, most estimates range between 30 and 50 years. Alternatives are available for some usages. For many cryogenics uses, however, there is no equivalent. Without helium, there is simply no other way to cool matter so close to absolute zero.

Mark Stokes is a senior research fellow in psychiatry and experimental psychology at Oxford University

navrig

ben@31 wrote:

bernithebiker wrote:

Oh and recently saw an article about a potential ban on using helium to fill balloons as it's becoming much rarer.

Rubbish.

You can't create or destroy helium. Just move it about. As soon as the balloon inevitably bursts the helium will return back to the atmosphere.

He's right.

You are correct in that you cannot CREATE Helium but you can and do abstract or recover it from other matural materials. As such once it is released to the atmosphere it is "lost".

As of 2012 the United States National Helium Reserve accounted for 30 percent of the world's helium.[36] The reserve was expected to run out of helium in 2018.[36] Despite that a proposed bill in the United States Senate would allow the reserve to continue to sell the gas. Other large reserves were in the Hugoton in Kansas, United States and nearby gas fields of Kansas and the panhandles of Texas and Oklahoma. New helium plants were scheduled to open in 2012 in Qatar, Russia and the United States state of Wyoming but they were not expected to ease the shortage.[36]

Taken from Wiki

http://en.wikipedia.org/wiki/Helium#Extraction_and_use

Guanajuato

Going way off topic here. Once its lost to the atmosphere its so bouyant that it ends up being lost to 'space'. It CAN be created - that's how that ball of fire we occasionally see in the sky works. It's also produced in fusion reactors, such as JET and ITER (when/if it gets built). But that's rather expensive and doesn't help us on bikes, until they can fit a fusion reactor in the frame.

gwebb118

Berni...(Sorry, slight edit from reading your post again) He2 used for tyre inflation and balloons will only use a tiny tiny amount of the He on earth compared to its use as a cryogenic coolants.
Also, CO2 is not smaller than air. Air actually contains CO2, and CO2 is relatively quite a large molecule compared to the major components of air (N2 and O2). The reason it leaks out of tyres is because is is polar and interacts with the rubber, making it soluble. N2 and O2 (from pumping tires with air) are not polar, so are not soluble in rubber (well technically they are very very slightly soluble, as everything is).
He2 is inert, and doesn't react with anything under normal conditions.
Argon is not radioactive (well maybe one isotope of it which is like 0.001% of it, but this makes no difference in the grand scheme of things, as it is also a component of air (~1%))

ricky1980

i was thinking of radon when i wrote radioactivity...der on my part. but yes there is an isotope of argon out there.

is CO2 canister storing liquid CO2? CO2 has a very short phase in which it is in a liquid form. thus Dry ice (solid CO2) almost immediately turn into the gaseous phase of CO2. I would be intrigued to know if this liquid form is stored in the canisters. but never the less, even it is highly compressed gaseous form of CO2, the expansion from a high pressure to low pressure will cause the temperature drop around the casing. it's simple fluid and thermal dynamics and laws of energy conservation. The canisters aren't necessarily cold normally as otherwise you need to refrigerate them. it only gets cold during the process of gas expansion. and that works for all gases, try it with a balloon blow up by your own breath. then hold the mouth piece and left the air go, the mouth piece will feel cold afterwards.

if bike tyre deflates very suddenly, then the inner tube will feel colder than before. the very same principle.

Lycra-Byka

178gm per tube! Lol

You'd definatly feel that weight!

If it was filled with bread or rice grains maybe 178gm would be gained.

100psi He in an innertube would be unusable after 10 mins riding I reckon?

charlie_potatoes

I got a really nasty burn from a CO2 canister when I foolishly unscrewed the valve when there was still some left in there.
It blistered up quite badly despite my applying liberal amounts of rule 5.

oldwelshman

too expensive and would leak, also if all cyclists did this there would be none for mri scanners