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Long Distance Ski Trail
A cross-country skiing trail or ''loipe''From german: Loipe or ''Langlaufloipe'', pl. –''n'', ''loipe'' is a loanword in English-language travel guides, referring to cross-country ski trails in Europe. It is a Germanization of the Norwegian word, ''løype,'' which originally meant a steep channel used to slide logs downhill into the valleys and which in turn came from the verb ''laupe'' ("run") whose causative ''løype,'' can translate as "to get running". is a route that has been laid out, constructed and maintained specifically for cross-country skiing. Trails may extend point-to-point, but are more typically loops for recreational use or for competition. Until the mid-20th Century, trails were tracked by the passage of skiers. More recently, snow groomers set tracks for classic skiing and smooth lanes for skate skiing. Recreational Cross-country ski venues often comprise a system of trails or ''loipes'' of varying length and difficulty that loop back to a starting point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-Country Ski Association Of America-Easy
Cross country or cross-country may refer to: Places * Cross Country, Baltimore, a neighborhood in northwest Baltimore, Maryland * Cross County Parkway, an east–west parkway in Westchester County, NY * Cross County Shopping Center, a mall in Yonkers, NY ** The Mall at Cross County, a smaller mall adjacent to the Cross County Shopping Center in Yonkers, NY Media and entertainment * ''CMT Cross Country'', an American television series * ''Cross Country'' (album), an album by Webb Pierce * Cross Country (band), a band formed in 1973 * ''Cross Country'' (film), a 1983 drama film starring Nina Axelrod * Cross-Country (G.I. Joe), a fictional character in the G.I. Joe universe * ''Cross Country'' (novel), a 2008 novel by James Patterson * '' Cross Country USA'' (1988), an edutainment videogame by Didatech Sports * Cross country running, a sport in which teams of runners compete to complete a course over open or rough terrain * Cross-country cycling, the most common discipli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sintering
Clinker nodules produced by sintering Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum. The study of sintering in metallurgical powder-related processes is known as powder metallurgy. An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Examples of pressure-driven sintering are the compact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Radiation
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-violet Radiation
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
