Parachute

UNISHALE B. The UNISHALE process, like the Paraho process, uses lump feed and countercurrent flows, and can be operated ia either the DH or IH mode. The UNISHALE B process is an IH process that uses hot recycled gas as the heat-transport medium (Fig. 6). The unique feature of the UNISHALE processes is the rock pump. The soflds move upward through the retort as the vapors are moving downward. The rock pump was used ia the UNISHALE technology at Parachute, Colorado to produce more than 0.64 x 10 m (four million battels) of cmde shale oil. Operations were shut down in 1991. 

Air Pollution. Particulates and sulfur dioxide emissions from commercial oil shale operations would require proper control technology. Compliance monitoring carried out at the Unocal Parachute Creek Project for respirable particulates, oxides of nitrogen, and sulfur dioxide from 1986 to 1990 indicate a +99% reduction in sulfur emissions at the retort and shale oil upgrading faciUties. No violations for unauthorized air emissions were issued by the U.S. Environmental Protection Agency during this time (62). 

Water Quality. AH commercial oil shale operations require substantial quantities of water. AH product water is treated for use and operations are permitted as zero-discharge facHities. In the Unocal operation, no accidental releases of surface water have occurred during the last four years of sustained operations from 1986 to 1990. The Unocal Parachute Creek Project compliance monitoring program of ground water, surface water, and process water streams have indicated no adverse water quaHty impacts and no violations of the Colorado Department of Health standards (62). 

Solids. Proper handling and disposal techniques can obviate potential problems associated with the soHd waste-retorted shale. Retorted shale disposal and revegetation have posed no adverse environmental impacts at the Unocal Parachute Project (62). EarHer studies carried out using Paraho and Lurgi retorted shales indicated that these materials behave as low grade cements (63,64) and can be engineered and compacted into high density materials (Pig. 11) and water impervious stmctures (Table 15). 

United States. In 1980, Unocal began constmcting the Parachute Creek Project, designed to produce 1600 m (10,000 bbl) of upgraded shale oil per day. The project included a conventional underground room-and-pikar mine, the Unishale B (see Table 7) retort, and a special Unocal upgrading facihty. Plant startup occurred in 1986, and daily shale oil production reached 1100 m /d (7000 bbl/d). By 1991, total production exceeded 0.6 x 10 m (four million barrels). However, the Parachute Creek Project was shut down in mid-1991 for economic reasons. 

An Environmental Impact Analysisfor a Shale Oil Complex at Parachute Creek, Colorado, Vol. I, II, III, Colony Development, Denver, Colo., 1974. 

Air Permeability. Air permeabiUty is an important parameter for certain fabric end uses, eg, parachute fabrics, boat sails, warm clothing, rainwear, and industrial air filters. Air permeabiUty of a fabric is related to its cover, or opacity. Both of these properties are related to the amount of space between yams (or fibers in the case of nonwovens). The most common method for specifying air permeabiUty of a fabric involves measuring the air flow per unit area at a constant pressure differential between the two surfaces of the fabric. This method, suitable for measuring permeabiUty of woven, knitted, and nonwoven fabrics, is described in ASTM D737. Units for air permeabiUty measured by this method are generally abbreviated as CFM, or cubic feet per square foot per minute. 

Leaving aside rayon and artificial silks generally, the first really effective polymeric textile fibre was nylon, discovered by the chemist Wallace Hume Carothers (1896-1937) in the Du Pont research laboratories in America in 1935, and first put into production in 1940, just in time to make parachutes for the wartime forces. This was the first of several major commodity polymer fibres and, together with high-density polyethylene introduced about the same time and Terylene , polyethylene tereph-thalate, introduced in 1941 (the American version is Dacron), transformed the place of polymers in the materials pantheon. 

Nuclear weapons (war)d d Underwater construction d Sport parachutes d Coal mining accidents d General aviation... 

Fall-schinn, m. parachute, -schirmleuchte, /. parachute flare, -silber, n. deposited silver, -sucht, /. epilepsy, -tiir, /. trapdoor. 

Schirm, m. screen shelter, shade umbrella parachute visor (of a cap) Bot.) umbel, -bild, n. screen image, schirmen, v.t. screen shelter protect. Schirm-gitter, n. Radio) screen grid, -gitter-rohre, /. screen id tube, -pflanze, /. umbelliferous plant, -wirkung, /. screening or shielding effect. 

Nylons have a variety of uses ranging from tire cord to carpet to hosiery. The most important application is cord followed by apparel. Nylon staple and filaments are extensively used in the carpet industry. Nylon fiber is also used for a variety of other articles such as seat belts, monofilament finishes, and knitwear. Because of its high tenacity and elasticity, it is a valuable fiber for ropes, parachutes, and underwear. 

Flares, Signaling Devices, and other Pyrotechnics. A large number of formulations contg K perchlorate have been reported. Some devices which use these are red RR signal flares (Refs 2 22, p 275) parachute flares (Ref 6) stars for use in signaling pistols (Very pistols) (Refs 5. 22, p 275) variously colored flares (Refs 19, pp 197-8 22, p 275) stars and other components of display fireworks (Refs 16 32) ... 

During World War II, nylon became an Allied weapon, along with Carothers Neoprene, Midgley s tetraethyl lead and Freon, and DDT (Chapter 8). The military diverted all available nylon for use in parachutes, airplane tire cords, glider towropes, tents, and the like. Nylon tires enabled bombers and carrier planes fueled with tetraethyl lead to withstand overloading. 

Cut a throwing line of fairly heavy smooth cord about four times as long as the distance from the ground to the target cable. The suspension lines of a parachute are excellent if available. 

History The secret was released some time after World War II when it became apparent that British forces provided a grenade specially concocted with botulinal toxins to kill Reinhard Heydrich, the much feared head of the Nazi Security Service, better known as the SD. After the successful killing in the Prague, Czechoslovakia, the stunned Germans shot and burned the town of Lidice (where free-Czechs from Britain had been parachuted in kill Heydrich), and arrested an estimated 10,000 Czechs. 

Compared to other risky activities, such as parachuting or motorcycling, risks related to food safety are unique. While some risks can be avoided, food safety-related risks can only be bypassed to a limited extent. Even when a person switches from one product to another, contaminated food still remains harder to avoid than parachuting, especially in the incipient phase where the risk is not yet known to the public and when consumers do not have full control over these risks. 

One of the larger uses of nylon fibers is tire cord. In apparel applications, which are another major area, permanent press can be achieved by heat treatment. This crease resistance lasts until abrasion, hear, or pressure wears down the molecule orientation. Since it is strong and lightweight, nylon also is used for rope, parachutes, and some undergarments. 

For the more adventurous, parachute rockets are available in 22 and 25 mm calibre, or even festoons or bag rockets with sticks up to three metres in length. The latter are definitely fired individually ... 

Parachute rockets work on much the same principle, except that the ejection charge pushes out a tube of flare composition, or any other composition, which is connected to the parachute which itself is folded beneath the end-cap at the top of the rocket. 

Parachutes deploy at the 300 m, or so, maximum altitude, the timing of the effects being set by fuses. 

As women s hemlines rose in the 1930s, silk stockings were in great demand but were very expensive. Nylon changed this, as it could be woven into sheer hosiery. The initial presentation of nylon hose to the public was by Stine at a forum of women s club members in New York City on October 24, 1938. Nearly 800,000 pairs were sold on May 15, 1940 alone—the first day they were on the market. By 1941 nylon hosiery held 30% of the market but by December 1941 nylon was diverted to make parachutes etc. 

Wallace Carothers and coworkers at DuPont synthesized aliphatic polyesters in the 1930s [Furukawa, 1998 Hounshell and Smith, 1988]. These had melting points below 100°C, which made them unsuitable for firber use. Carothers then turned successfully to polyamides, based on the theoretical consideration that amides melt higher than esters. Polyamides were the first synthetic fibers to be produced commercially. The polyester and polyamide research at DuPont had a major impact on all of polymer science. Carothers laid the foundation for much of our understanding of how to synthesize polymeric materials. Out of that work came other discoveries in the late 1930s, including neoprene, an elastomer produced from chloro-prene, and Teflon, produced from tetrafluoroethylene. The initial commercial application for nylon 6/6 was women s hosiery, but this was short-lived with the intrusion of World War II. The entire nylon 6/6 production was allocated to the war effort in applications for parachutes, tire cord, sewing thread, and rope. The civilian applications for nylon products burst forth and expanded rapidly after the war. 

Nylon finally became available to the general public in May 1940. Ten years had passed from initial discovery to full commercialization. It was a tremendous effort, even for a company with the resources of DuPont, and the R D cost was 4.3 million. During World War II, DuPont nylon production went up to 25 million pounds a year, and was used to make parachutes, airplane tire cords, and glider tow ropes. DuPont resumed selling nylon for stockings after the war. 

Clinical studies also supported the importance of SP in stress responses and regulation of anxiety level. Even clinically healthy persons showed increased plasma SP levels in extreme stress situations such as war (Weiss et al. 1996) or parachute jumping (Schedlowski et al. 1995). 

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