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Wetsuits
A wetsuit is a garment worn to provide thermal protection while wet. It is usually made of foamed neoprene, and is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports and other activities in or on water. Its purpose is to provide thermal insulation and protection from abrasion, ultraviolet exposure, and stings from marine organisms. It also contributes extra buoyancy. The insulation properties of neoprene foam depend mainly on bubbles of gas enclosed within the material, which reduce its ability to conduct heat. The bubbles also give the wetsuit a low density, providing buoyancy in water. Hugh Bradner, a University of California, Berkeley physicist, invented the modern wetsuit in 1952. Wetsuits became available in the mid-1950s and evolved as the relatively fragile foamed neoprene was first backed, and later sandwiched, with thin sheets of tougher material such as nylon or later spandex (also known as lycra). Improvements in the way joints ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Suit
A diving suit is a garment or device designed to protect a diver from the underwater environment. A diving suit may also incorporate a breathing gas supply (such as for a standard diving dress or atmospheric diving suit). but in most cases the term applies only to the environmental protective covering worn by the diver. The breathing gas supply is usually referred to separately. There is no generic term for the combination of suit and breathing apparatus alone. It is generally referred to as diving equipment or dive gear along with any other equipment necessary for the dive. Diving suits can be divided into two classes: "soft" or ambient pressure diving suits – examples are wetsuits, dry suits, semi-dry suits and dive skins – and "hard" or atmospheric diving suit, atmospheric pressure diving suits, armored suits that keep the diver at atmospheric pressure at any depth within the operating range of the suit. Function The diving suit is worn as protection from the diving envi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triathlons
A triathlon is an endurance multisport race consisting of swimming, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each segment sequentially with the time transitioning between the disciplines included. The word is of Greek origin, from τρεῖς or ''treis'' (three) and ἆθλος or ''athlos'' (competition). The sport originated in the late 1970s in Southern California as sports clubs and individuals developed the sport. This history has meant that variations of the sport were created and still exist. It also led to other three-stage races using the name triathlon despite not being continuous or not consisting of swim, bike, and run elements. Triathletes train to achieve endurance, strength and speed. The sport requires focused persistent and periodised training for each of the three disciplines, as well as combination workouts and general strength conditioning. History The evolution of triathlon as a distinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Water Swimming
Open water swimming is a swimming discipline which takes place in outdoor bodies of water such as open oceans, lakes, and rivers. The beginning of the modern age of open water human swimming, swimming is sometimes taken to be May 3, 1810, when Lord Byron swam several miles to cross the Dardanelles, Hellespont (now known as the Dardanelles) from Europe to Asia. In the first edition of the modern Olympic Games in Athens in 1896, the swimming competition was held in open water. In 2000, the Olympic Games first included a triathlon with a 1500 m swim leg, and in 2008, a Swimming at the 2008 Summer Olympics – Men's marathon 10 kilometre, 10 km open water swim. The FINA World Aquatics Championships has featured open water swimming events since 1992. The FINA World Open Water Swimming Championships was held from 2000 to 2010. Since 2007, the FINA Marathon Swim World Series, FINA 10 km Marathon Swimming World Cup is held in several events around the world. The activity has g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Bradner
Hugh Bradner (November 5, 1915 – May 5, 2008) was an American physicist at the University of California who is credited with inventing the neoprene wetsuit, which helped to revolutionize scuba diving and surfing. A graduate of Ohio's Miami University, he received his doctorate from California Institute of Technology in Pasadena, California, in 1941. He worked at the US Naval Ordnance Laboratory during World War II, where he researched naval mines. In 1943, he was recruited by Robert Oppenheimer to join the Manhattan Project at the Los Alamos Laboratory. There, he worked with scientists including Luis Alvarez, John von Neumann and George Kistiakowsky on the development of the high explosives and exploding-bridgewire detonators required by atomic bombs. After the war, Bradner took a position studying high-energy physics at the University of California, Berkeley, under Luis Alvarez. Bradner investigated the problems encountered by frogmen staying in cold water for long periods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoprene
Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene.Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion Rubbers" in Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range. Neoprene is sold either as solid rubber or in latex form and is used in a wide variety of commercial applications, such as laptop sleeves, orthopaedic braces (wrist, knee, etc.), electrical insulation, liquid and sheet-applied elastomeric membranes or flashings, and automotive fan belts. Production Neoprene is produced by free-radical polymerization of chloroprene. In commercial production, this polymer is prepared by free radical emulsion polymerization. Polymerization is initiated using potassium persulfate. Bifunctional nucleophiles, metal oxides (e.g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Rafting
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague. Rivers are part of the water cycle. Water generally collects in a river from precipitation through a drainage basin from surface runoff and other sources such as groundwater recharge, springs, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitewater Kayaking
Whitewater kayaking is an adventure sport where a river is navigated in a decked kayak. Whitewater kayaking includes several styles. River running; where the paddler follows a river and paddles rapids as they travel. Creeking usually involving smaller, steeper, and more technical waterways. Creek boats tend to be short but high volume to allow for manoeuvrability while maintaining buoyancy. Slalom requires paddlers to navigate through "gates" (coloured poles hanging above the river). Slalom is the only whitewater event to be in the Olympics. Play boating involves staying on one feature of the river and is more artistic than the others. Squirt boating uses low-volume boats (usually made specifically for the paddler) to perform special moves in whitewater features. History Paddling on rivers, lakes and oceans is as old as the Stone Age. The raft, the catamaran, the canoe and the kayak evolved depending on the needs and environment of the indigenous peoples in different parts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rafting
Rafting and whitewater rafting are recreational outdoor activities which use an inflatable raft to navigate a river or other body of water. This is often done on whitewater or different degrees of rough water. Dealing with risk is often a part of the experience. This activity as an adventure sport has become popular since the 1950s, if not earlier, evolving from individuals paddling to rafts with double-bladed paddles or oars to multi-person rafts propelled by single-bladed paddles and steered by a person at the stern, or by the use of oars. Rafting on certain sections of rivers is considered an extreme sport and can be fatal, while other sections are not so extreme or difficult. Rafting is also a competitive sport practiced around the world which culminates in a world rafting championship event between the participating nations. The International Rafting Federation, often referred to as the IRF, is the worldwide body which oversees all aspects of the sport. Equipme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convection
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be transient (such as when a multiphase mixture of oil and water separates) or steady state (see Convection cell). The convection may be due to gravitational, electromagnetic or fictitious body forces. Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be identified by clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics. Convection is often categorised or d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
