Roller Ski
Roller skiing is an off-snow equivalent to cross-country skiing. Roller skis have wheels on their ends and are used on a hard surface, to emulate .Bryhn, Rolf and Knut Are Tvedt (eds.): ''Kunnskapsforlagets idrettsleksikon''. (Norwegian Encyclopedia of Sports). Oslo: Kunnskapsforlaget, 1990. The skiing techniques used are very similar to techniques used in cross-country skiing on snow. First created as a summer training exercise, roller skiing grew into a competitive sport in its own right. Annual championships are held in various locations around the world. Most, if not all, national cross-country ski teams around the world roller ski during the off-season for specific physical training simulating winter skiing. In Norway, separate roller ski facilities have been constructed to allow exercise off public roads. History The first roller skis were built in the mid-1930s in Italy and North Europe. In the early 1950s, when cross-country skiing started to evolve to a serious competit ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires. It is typically spun into ropes or fabric sheets that can be used as such, or as an ingredient in composite material components. Kevlar has many applications, ranging from bicycle tires and racing sails to bulletproof vests, all due to its high tensile strength-to-weight ratio; by this measure it is five times stronger than steel. It is also used to make modern marching drumheads that withstand high impact; and for mooring lines and other underwater applications. A similar fiber called Twaron with the same chemical structure was developed by Akzo in the 1970s; commercial production started in 1986, and Twaron is now manufactured by Teijin. History Poly-paraphenylene terephthalamide (K2 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states (Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th parallel, with ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Territories (NWT) to the north, and the U.S. state of Montana to the south. It is one of the only two landlocked provinces in Canada (Saskatchewan being the other). The eastern part of the province is occupied by the Great Plains, while the western part borders the Rocky Mountains. The province has a predominantly continental climate but experiences quick temperature changes due to air aridity. Seasonal temperature swings are less pronounced in western Alberta due to occasional Chinook winds. Alberta is the fourth largest province by area at , and the fourth most populous, being home to 4,262,635 people. Alberta's capital is Edmonton, while Calgary is its largest city. The two are Alberta's largest census metropolitan areas. More tha ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Canada, it is Canada's most populous province, with 38.3 percent of the country's population, and is the second-largest province by total area (after Quebec). Ontario is Canada's fourth-largest jurisdiction in total area when the territories of the Northwest Territories and Nunavut are included. It is home to the nation's capital city, Ottawa, and the nation's most populous city, Toronto, which is Ontario's provincial capital. Ontario is bordered by the province of Manitoba to the west, Hudson Bay and James Bay to the north, and Quebec to the east and northeast, and to the south by the U.S. states of (from west to east) Minnesota, Michigan, Ohio, Pennsylvania, and New York. Almost all of Ontario's border with the United States f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Helmet
A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protective function are sometimes worn. Soldiers wear combat helmets, often made from Kevlar or other lightweight synthetic fibers. The word ''helmet'' is derived from ''helm'', an Old English word for a protective head covering. Helmets are used for recreational activities and sports (e.g., jockeys in horse racing, American football, ice hockey, cricket, baseball, camogie, hurling and rock climbing); dangerous work activities such as construction, mining, riot police, military aviation, and in transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids. Designs Some British gamekeepers during the 18th and 19th centuries wore he ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Glove
A glove is a garment covering the hand. Gloves usually have separate sheaths or openings for each finger and the thumb. If there is an opening but no (or a short) covering sheath for each finger they are called fingerless gloves. Fingerless gloves having one small opening rather than individual openings for each finger are sometimes called gauntlets, though gauntlets are not necessarily fingerless. Gloves which cover the entire hand or fist but do not have separate finger openings or sheaths are called mittens. Mittens are warmer than other styles of gloves made of the same material because fingers maintain their warmth better when they are in contact with each other; reduced surface area reduces heat loss. A hybrid of glove and mitten contains open-ended sheaths for the four fingers (as in a fingerless glove, but not the thumb) and an additional compartment encapsulating the four fingers. This compartment can be lifted off the fingers and folded back to allow the individual fi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tungsten Carbide
Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes through sintering for use in industrial machinery, cutting tools, chisels, abrasives, armor-piercing shells and jewelry. Tungsten carbide is approximately twice as stiff as steel, with a Young's modulus of approximately 530–700 GPa, and is double the density of steel—nearly midway between that of lead and gold. It is comparable with corundum (α-) in hardness and can be polished and finished only with abrasives of superior hardness such as cubic boron nitride and diamond powder, wheels and compounds. Naming Historically referred to as Wolfram, ''Wolf Rahm'', wolframite ore was then later carburized and cemented with a binder creating a composite now called "tungsten carbide". Tungsten is Swedish for "heavy stone". Col ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ski Pole
Ski poles, also referred to as poles (in North America), sticks (UK), or stocks (Australia), are used by skiers for balance and propulsion. Modern ski poles are most commonly made from aluminum and carbon fiber, though materials such as bamboo are still used. Poles are used in alpine skiing, freestyle skiing (with the exception of aerials), and cross-country skiing. Ski jumpers do not use poles. History , the earliest ski pole was found in Sweden and dates back to 3623 BC, while the earliest depiction of a man with a ski pole was found in Norway in the form of a cave painting, dated at 4000 BC. Early skiers would use this pole for the purposes of balancing, braking, and turning. Alpine societies such as those in Nordic regions or the Altai mountains used their ski poles to hunt as well, giving them spear-like qualities. Skiers began to use two ski poles in 1741. This provided greater balance than one pole could provide and made pushing through the snow easier. Early ski po ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ski Boot
Ski boots are footwear used in skiing to provide a way to attach the skier to skis using ski bindings. The ski/boot/binding combination is used to effectively transmit control inputs from the skier's legs to the snow. History Ski boots were leather winter boots, held to the ski with leather straps. As skiing became more specialized, so too did ski boots, leading to the splitting of designs between those for alpine skiing and cross-country skiing (sport), cross-country skiing. Modern skiing developed as an all-round sport with uphill, downhill and cross-country portions. The introduction of the cable binding started a parallel evolution of binding and boot. The binding looped a strap around the back of the boot to hold it forward into a metal cup at the toe. Boots with the sole extended rearward to produce a flange for the cable to firmly latch to become common, as did designs with semi-circular indentations on the heel for the same purpose. Effective cross-country skiing requires ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ski Binding
A ski binding is a device that connects a ski boot to the ski. Before the 1933 invention of ski lifts, skiers went uphill and down and cross-country on the same gear. As ski lifts became more prevalent, skis—and their bindings—became increasingly specialized, differentiated between alpine (downhill) and Nordic ( cross-country, Telemark, and ski jumping) styles of skiing. Until the point of divergence in the mid-20th century, bindings held the toe of a flexible, leather boot against the ski and allowed the heel to rise off the ski, typically with a form of strap or cable around the heel. To address injuries resulting from falls while skiing downhill on such equipment, ski bindings emerged with the ability to release the toe of the boot sideways, in early models, and to release the boot forward and aft, in later models. Downhill ski bindings became standardized to fit plastic ski boots and incorporated a built-in brake that drags in the snow after the ski detaches from the boot. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Skike
A skike is a sports device consisting of two wheels attached to a frame that can be strapped onto the rider's shoe. Similarly to roller skis, the skike has a wheel in front and at the tail of an aluminium frame that can be attached to the foot. However, unlike roller skis and roller skates the tires are pneumatic. In addition to asphalt, the skikes can therefore be used on rougher terrain such as dirt roads, plaster and gravel. The skike straps onto the rider's shoe, and does not require any special type of boot. It has a brake on the heel that allows the rider to stop or brake gradually by pushing back the lower legs. The name skike is a combination of ''skate'' and ''bike''. The skike rider moves forward in a skating Skating involves any sports or recreational activity which consists of traveling on surfaces or on ice using skates, and may refer to: Ice Skating *Ice skating, moving on ice by using ice skates **Figure skating, a sport in which individuals, ... motion, usuall ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |