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== '''[[Acid rain]]''' ==
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'''Acid rain''' is a popular term for the atmospheric deposition of acidified [[rain]], [[snow]], sleet, hail and [[particulates]], as well as acidified [[fog]] and [[cloud]] [[water]]. The increased [[pH|acidity]] of these depositions, primarily from [[Sulfuric acid|sulfuric]] and [[nitric acid]]s, is generated as a by-product of the [[combustion]] of fuels,<ref>'''Note:''' Sulfuric acid is formed from the sulfur dioxide resulting from combustion of sulfur-containing fuels. Nitric acid is formed from the [[nitrogen oxides]] resulting from the high temperature partial conversion of the [[nitrogen]] contained in the combustion air.</ref> especially in [[fossil fuel]] [[power plant]]s. The heating of homes, electricity production, and driving vehicles all rely primarily on fossil fuel [[Energy (science)|energy]]. When fossil fuels are burned, [[acid]]-forming [[nitrogen oxides]] and [[sulfur oxides]] are released to the [[atmosphere]]. These [[chemical compound]]s are transformed in the atmosphere, often traveling thousands of [[kilometer]]s from their original source, and then fall out on land and water surfaces as acid rain. As a result, air [[pollutant]]s from power plants in the states of  [[New Jersey]] or [[Michigan]] can impact pristine forests or lakes in undeveloped parts of the states of [[New Hampshire]] or [[Maine]].<ref name=eoearth>The primary source for this article was [http://www.eoearth.org/article/Acid_rain?topic=49506 Acid Rain] August 7, 2010 (last revised  October 19, 2010), Gene Likens (Lead author), Wayne Davis, Lori Zaikowski and Stephen C. Nodvin. (Published on the website of the [[Encyclopedia of Earth]])</ref>
==Footnotes==
 
Acid rain in [[North America]] was discovered in 1963 in rain at  the [[Hubbard Brook Experimental Forest]] (HBEF)<ref>'''Note:''' Site of the Hubbard Brook Ecosystem Study in the [[White Mountains]] of [[New Hampshire]]</ref> that was some 100 times more acidic than unpolluted rain. Innovations for reducing fossil fuel combustion [[Air pollution emissions|emissions]], such as scrubbers upstream of the tall [[flue gas stack]]s on power plants and other industrial facilities, [[catalytic converter]]s on automobiles, and use of low-[[sulfur]] [[coal]], have been employed to reduce emissions of [[sulfur dioxide]] (SO<sub>2</sub>) and nitrogen oxides (NOx).
 
''Note:'' While the examples in this article describe the North American situation, the nature and effects of acid rain are similar all over the world.
 
 
''[[Acid rain|.... (read more)]]''
 
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Latest revision as of 10:19, 11 September 2020

The Irvin pin. The eyes have always been red, but there are urban legends about the meanings of other colors.
A pin from another company, possibly Switlik or Standard Parachute. This style is common in catalogs and auctions of military memorabilia.

The Caterpillar Club is an informal association of people who have successfully used a parachute to bail out of a disabled aircraft. After authentication by the parachute maker, applicants receive a membership certificate and a distinctive lapel pin.

History

Before April 28, 1919 there was no way for a pilot to jump out of a plane and then to deploy a parachute. Parachutes were stored in a canister attached to the aircraft, and if the plane was spinning, the parachute could not deploy. Film industry stuntman Leslie Irvin developed a parachute that the pilot could deploy at will from a back pack using a ripcord. He joined the Army Air Corps parachute research team, and in April 1919 he successfully tested his design, though he broke his ankle during the test. Irvin was the first person to make a premeditated free fall jump from an airplane. He went on to form the Irving Airchute Company, which became a large supplier of parachutes. (A clerical error resulted in the addition of the "g" to Irvin and this was left in place until 1970, when the company was unified under the title Irvin Industries Incorporated.) The Irvin brand is now a part of Airborne Systems, a company with operations in Canada, the U.S. and the U.K.[1].

An early brochure [2] of the Irvin Parachute Company credits William O'Connor 24 August 1920 at McCook Field near Dayton, Ohio as the first person to be saved by an Irvin parachute, but this feat was unrecognised. On 20 October 1922 Lieutenant Harold R. Harris, chief of the McCook Field Flying Station, jumped from a disabled Loening W-2A monoplane fighter. Shortly after, two reporters from the Dayton Herald, realising that there would be more jumps in future, suggested that a club should be formed. 'Caterpillar Club' was suggested because the parachute canopy was made of silk, and because caterpillars have to climb out of their cocoons and fly away. Harris became the first member, and from that time forward any person who jumped from a disabled aircraft with a parachute became a member of the Caterpillar Club. Other famous members include General James Doolittle, Charles Lindbergh and (retired) astronaut John Glenn.

In 1922 Leslie Irvin agreed to give a gold pin to every person whose life was saved by one of his parachutes. By 1945 the number of members with the Irvin pins had grown to over 34,000. In addition to the Irvin Air Chute Company and its successors, other parachute manufacturers have also issued caterpillar pins for successful jumps. Irvin/Irving's successor, Airborne Systems Canada, still provides pins to people who made their jump long ago and are just now applying for membership. Another of these is Switlik Parachute Company, which though it no longer makes parachutes, still issues pins.

Footnotes