User talk:ThinkGreen

Thanks for visiting my talk page. I watch this closely, so writing here is probably the fastest way to get my attention.

Wikiproject Environment

Hello and welcome to wikiproject environment.--Alex 08:28, 1 October 2007 (UTC)

Hazards of Exploding Pop Bottles

I find your input on my article somewhat negative based solely on a lack of any suggestion as to where the article may best be suited. You are right in sensing my frustration which is largely generated by a lack of familiarity with the system. Any positive advice from experienced Wikepedia contributors would be appreciated. My own feeling is that the topic may warrant a new contribution status rather than forcing it into an existing article with common keyword headings. I would be grateful if you would help me get it located in the right location in Wikepedia. I have also taken on board one or two other suggestions with regard to including references. I would also be prepared to provide images of the severity of the explosions at various headspace volumes at some future time. The following is an updated version of my article with references, having studiously avoided referring to all but one of my own papers on the subject. It is not a topic that has been given any scientific analysis by anybody else. However, various reviews have been produced that I have referred to and which in turn make reference to my own scientic studies. I would be most grateful if, as an experienced Wikipeadian you could "install" the following article - thanks! --86.2.168.58 13:25, 1 October 2007 (UTC)

All unprotected glass bottles fracture if impacted with sufficient force. On most occasions that simply means dropping a bottle on to a hard floor, deliberately or, more often, by accident. Sometimes the failure is contemporaneous with the moment of impact; at other times, with lower energy impacts, there is a delay that could result in failure after a matter of seconds, minutes or even days following the impact, depending on the growth of the micro-fissure to a critical level and the residual stress in the glass. If the bottle contains a fizzy (carbonated) drink then catastrophic failure occurs with explosive violence. A damaged glass bottle containing a fizzy drink parallels a loaded gun with a hair trigger that is capable of spontaneous action.

The gas pressure increases with temperature by virtue of the decreasing solubility of gases in water with increasing temperature and, in a hot environment, can be 100 psi or more, such as when the capped bottle is left in direct sunlight or in a car on a hot day. Glass bottles are designed to withstand pressures in excess of 200 psi, but that means very little if the bottle has been subjected to impacts and abrasion that result in micro-fissures, thereby compromising its strength. In such circumstances, from the sustained carbonation pressure, spontaneous, explosive failure can occur with disastrous consequences. Being largely a child-line, it is the unsuspecting 5 to 14-year olds that more often fall prey to exploding bottles. By way of example, during 1989 to 1993 the UK Department of Trade and Industry (Home Accidents Surveillance ID System, Consumer Safety Unit, DTI) recorded 1645 injuries from exploding, pop bottles ranging from lacerations to loss of eyesight (R. Goddard, ‘The Packaging Week Safety & Security in Packaging Report’ 1997/98, Miller Freeman plc, ISBN 0-9521459-9-5; 1997, Norris, Hopkinson, Cobb & Wilson, ‘Potential hazards from carbonated drinks bottles’ University of Nottingham, published by the Consumer Safety Unit, DTI; 2004, Kuhn, Mester, Morris & Dalma, ‘Serious eye injuries caused by bottles containing carbonated drinks’, British Journal of Opthalmology, 88 (1)).

The ballistic energy of an exploding bottle for a given carbonation level known as carbonation volume (see below) is determined by the temperature and pressure above atmospheric pressure, known as the gauge pressure. {The theory is complex: a detailed analysis is available in Food Science and Technology Today 10(1) 1996}. The larger the headspace - i.e. gas volume between the liquid level and brim of the bottle - the more pressure energy is available to be transferred as kinetic energy to the shards of glass at the moment of failure. Conversely, the smaller the headspace, the less energy there is to propel the shards. A bottle filled brim-full with a carbonated drink has no pressure energy and, when it undergoes failure, it does so in exactly the same way as a bottle full of still water - i.e. without explosive force. For many years following first commercial bottling of carbonated drinks by Schweppe more than 200 years ago, there was the misconception by the bottling industry that a minimum headspace needed to exist in order to act as a pressure buffer for the carbon dioxide. The reality is that pressure remains practically unaffected by the magnitude of the headspace, in accordance with Henry’s Law of gas solubility that essentially states that, the mass of a gas dissolved by a given volume of liquid, at constant temperature, is proportional to the pressure of the gas with which it is in equilibrium. In other words, as the headspace decreases, then more gas becomes dissolved in the water to maintain a constant pressure in the headspace, and vice versa.

The ramification to this is that a fizzy drink becomes less hazardous from the point of view of its pressure energy, the smaller the headspace and that the internal pressure remains constant at a specific temperature and carbonation volume as the headspace volume is decreased (or increased). Thus, a bottle filled to 97.5% has about half the explosive energy as a bottle filled to 95%. With modern filling plant there is a very high level of precision in fill volumes which are determined, not by the bottle capacity, but by the fill height from the brim, hence the high achievable precision in fill height. It for this reason, that bottlers can readily and reliably reduce the pressure energy by maximising the fill level to within 1.5% of the brim volume which allows for any liquid expansion; water expands 1% over a 40 C temperature range above the chilled, filling temperatures on bottling plants.

In recognition of the avoidable pressure energy of carbonated drinks, in 1988 the British Standards Institute (BSI) recommended a maximum limit to headspace of 3.5% which, in practice, means a target fill of about 98.3%, to allow for statistical variations in fill levels whilst still allowing for liquid expansion. Because of the non-enforceable nature of the Standard, not all bottlers comply with it. But that is a risk that could prejudice a defence in any litigation and claim for injury compensation.

Recycling of glass, multi-trip bottles continues to be practised in Europe, especially among states strongly committed to minimising environmental pollution. However, recycling imposes rigorous checking of the condition of each bottle before it is re-filled with a carbonated drink. Such checking includes visual and in-line pressure testing with certain countries, such as Israel, making it a legal requirement to test at pressures well in excess of filling pressures.

The wide-spread introduction of plastic (PET) bottles, whilst having removed the fragmentation characteristic of exploding glass, is not entirely hazard free. The large size of the bottles - sometimes up to 3 litres, as opposed to not more than 1 litre for glass for reasons of safety - creates larger headspaces and, thereby, increased pressure energy within that headspace. If the cap thread crosses the thread of the neck of the bottle - this can happen when a sealed bottle has its cap twisted, the wrong way with a mechanical aid, causing it to jack into an, unstable and asymmetric position - then the cap may spontaneously “missile” from the bottle at theoretical velocities in excess of 300 mph. If the bottle is gripped in such a way as to allow the cap to impact an eye, then the victim loses an eye. There are several recorded cases of such missiling outcomes leading to loss of an eye, especially among children. The terms “missiling” and “tailing” are well known to the bottling industry and both relate to premature, explosive separation of the cap from the bottle, the latter at the tail-end of the neck thread where the vertical cuts designed to release gas whilst unscrewing the cap become choked by excessive frothing of the contents, typically from shaking or dropping the bottle.

For a while the bottling industry reacted to this hazard by attaching the cap to the neck of the bottle by a plastic strip forming an integral part of the closure design and known as a ‘pig’s tail’. This was not well received by consumers because the cap readily interfered with the pouring action. Under pressure from litigants by victims of such injuries the industry improved the closure design, dispensing with the captive concept and providing graphic displays of the direction in which to twist the cap for its controlled removal plus other warnings of the hazards such as “Store in a cool place, out of direct sunlight. Cover cap when opening, pointing away from face. Do not use mechanical aid.”. There have been many civil compensation claims against bottlers for injuries to victims of exploding bottles in the last 20 years; the vast majority have been settled out of court.

Carbonation Volume

The volume of carbon dioxide (CO₂) gas at one atmosphere pressure (1 bar at 20<^oC defined in British Standard BS:6119 Part 1, 1981) dissolved in a soft drink is known as the carbonation volume. Some countries use a different and, arguably, less confusing measure of carbonation by referring to the mass of gas dissolved in a litre of the water, or as a percentage (w/v) of the water. One carbonation volume is equal to 1.95 g of carbon dioxide in a litre of water, or 0.195% w/v. The gas space between the liquid level and the brim is the headspace volume expressed either as a percentage volume of the bottle capacity, or in units of ml. An alternative measure of headspace volume, widely adopted in English speaking countries, is "vacuity". This method of quantifying headspace is less helpful in that it is expressed as the headspace relative to the liquid volume and normally expressed as a percentage (v/v). For small headspace volumes (less than 10%), headspace volume and vacuity (C) numerically approach one another with decreasing volume. However, a vacuity of 100% means a half-full bottle: i.e. the headspace volume is the same as the liquid volume from the definition of C, vis:

C = {H/L} x 100%

Target vacuities for litre bottles are 3.5% in the UK and generally between 3.5 and 4.5% elsewhere. The lower target vacuity in the UK, introduced in 1988 by the BSI, is a recognition of the potential hazards of uncontrolled release of the pressure energy within the headspace volume - determined by the absolute volume and carbonation pressure - in the event of bottle failure (qv hazards of exploding pop bottles).

If your intent was to point out the sources that you have cited or defend its inclusion in the article, you should do so on the carbonation talk page so that all may read it. I would recommend you consider formatting your citations so that they are easily readable and quickly identifiable (i.e. with footnotes or endnotes) and add sources for numbers that are not cited from any source that could be contested. See WP:CITE for help.

Also, my issue with this content's inclusion extends beyond a lack of adequate sources for some parts of the article. This material seems very specific and technical for a popular science article; by that, I mean it is rather unencyclopedic in content, as parts of it read like original research -- which is prohibited by Wikipedia's Five Pillars. This is not to say that it is not good information, but as a policy wikipedia does not allow anything that is not verifiable and could be construed as "original research."

If your contrition does not draw from original research and you are you are committed to expanding information on this topic then I encourage you to start your own article and link it from related pages like "soft drinks" and "carbonation" in the related links sections of those pages.

Any logged in user can create a new article: instructions are here. I have never personally started a new article, but I am confident that if you take the time to read the instructions at that page that you will be able to figure it out and give your contribution an appropriate home.

--ThinkGreen 14:11, 1 October 2007 (UTC)

233 = BFF?

I'm wondering, how does 233 equal BFF? Is it because of the telephone keypad? Is there any citation for this? Anton Mravcek 22:30, 1 October 2007 (UTC)

Yes, 233 equals BFF because of the reference to standard telephone keypads. I can't seem to find any kind of credible source so you can remove it if you want, but it's something I would consider to be very common knowledge among Americans of a certain age group that could be useful information to older adults in trying to "decode" what young people are saying. Given that and the fact that none of the other number trivia on the 230 (number) page were given citations, I think it should probably stay. --ThinkGreen 02:40, 2 October 2007 (UTC)

About "User:Hempfel"

Sorry. I will correct that ASAP. —Preceding unsigned comment added by Hempfel (talk • contribs) 22:52, 22 November 2007 (UTC)

Spam in Energy Harvesting

Hi ThinkGreen. I see you removed the Spam tag on Energy harvesting. As a matter of fact, you may have noticed in the history that this article used to be spammed much more in the past. I had complaints from companies very recently about the bias in favor of some emerging start-ups. I removed some links but, they might come back and spam the article again in a (very) near future. I try to watch this article as closely as possible but I am more active on French Wiki and I do not come here everyday. Regards. Tizeff (talk) 10:06, 13 February 2008 (UTC)

Speedy deletion of Image:Plasticbottles2.jpg

A tag has been placed on Image:Plasticbottles2.jpg requesting that it be speedily deleted from Wikipedia. This has been done under section I3 of the criteria for speedy deletion, because it is an image licensed as "for non-commercial use only," "non-derivative use" or "used with permission," it has not been shown to comply with the limited standards for the use of non-free content. [1], and it was either uploaded on or after 2005-05-19, or is not used in any articles. If you agree with the deletion, there is no need to do anything. If, however, you believe that this image may be retained on Wikipedia under one of the permitted conditions then:

• state clearly the source of the image. If it has been copied from elsewhere on the web you should provide links to: the image itself, the page which uses it and the page which contains the license conditions.
• add the relevant copyright tag.

If you think that this notice was placed here in error, you may contest the deletion by adding {{hangon}} to the top of the page that has been nominated for deletion (just below the existing speedy deletion or "db" tag), coupled with adding a note on [[ Talk:Image:Plasticbottles2.jpg|the talk page]] explaining your position, but be aware that once tagged for speedy deletion, if the article meets the criterion it may be deleted without delay. Please do not remove the speedy deletion tag yourself, but don't hesitate to add information to the article that would would render it more in conformance with Wikipedia's policies and guidelines. Lastly, please note that if the article does get deleted, you can contact one of these admins to request that a copy be emailed to you. Kelly ^hi! 17:32, 12 June 2008 (UTC)