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Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency. Composition The material used in tennis string can significantly affect a player's performance, and even health. Several materials are used to make tennis strings. They vary in terms of elasticity, durability, rebound efficiency, tension holding capability, and manufacturing cost, among other considerations. Natural gut Animal intestine is the most resilient material used to make tennis strings. It has better tension retention than any other material, and also is softer than any other material used for tennis strings. It provides the most energy return, meaning it is the most efficient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prince Syngutdf Auflicht
A prince is a male ruler (ranked below a king, grand prince, and grand duke) or a male member of a monarch's or former monarch's family. ''Prince'' is also a title of nobility (often highest), often hereditary, in some European states. The female equivalent is a princess. The English word derives, via the French word ''prince'', from the Latin noun , from (first) and (head), meaning "the first, foremost, the chief, most distinguished, noble ruler, prince". Historical background The Latin word (older Latin *prīsmo-kaps, literally "the one who takes the first lace/position), became the usual title of the informal leader of the Roman senate some centuries before the transition to empire, the ''princeps senatus''. Emperor Augustus established the formal position of monarch on the basis of principate, not dominion. He also tasked his grandsons as summer rulers of the city when most of the government were on holiday in the country or attending religious rituals, and, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustavo Kuerten French Open 2005
Gustavo is the Latinate form of a Germanic male given name with respective prevalence in Portuguese, Spanish, and Italian. It has been a common name for Swedish monarchs since the reign of Gustav Vasa. It is derived from Gustav /ˈɡʊstɑːv/, also spelled Gustaf, of Old Swedish origin, meaning “staff of the Gods/Goths” or “great royal staff” or "staff of the Geats", derived from the Old Norse elements Gautr ("Geat") and stafr ("staff"). Other Swedish variants/derivatives: Gösta, Göstav, Gustafsson, Gustavsson. Such a name is also etymologically indicative of a Slavonic origin (through Swedish) from "Gostislav", a compound word from Old Slavic "Gost'" ("guest") and "slava" ("glory"). Other Slavonic variants/derivatives: Goslav, Gustaw, Gusti, Gustik, Gusty. Such a name in the United States also bears diminutive forms in English, which serve as nick names: Gus, Gussie, Gussy, Goose. To avoid confusion, note that these nick names are also commonly used for a different c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pound-force
The pound of force or pound-force (symbol: lbf, sometimes lbf,) is a unit of force used in some systems of measurement, including English Engineering units and the foot–pound–second system. Pound-force should not be confused with pound-mass (lb), often simply called ''pound'', which is a unit of mass, nor should these be confused with foot-pound (ft⋅lbf), a unit of energy, or pound-foot (lbf⋅ft), a unit of torque. Definitions The pound-force is equal to the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth. Since the 18th century, the unit has been used in low-precision measurements, for which small changes in Earth's gravity (which varies from equator to pole by up to half a percent) can safely be neglected. The 20th century, however, brought the need for a more precise definition, requiring a standardized value for acceleration due to gravity. Product of avoirdupois pound and standard gravity The pound-force is the product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot
A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ''bend'' fastens two ends of a rope to each another; a ''loop knot'' is any knot creating a loop; and ''splice'' denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory. History Knots and knotting have been used and studied throughout history. For example, Chinese knotting is a decorative handicraft art that began as a form of Chinese folk art in the Tang and Song Dynasty (960–1279 AD) in China, later popularized in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half Hitch
The half hitch is a simple overhand knot, where the working end of a line is brought over and under the standing part. Insecure on its own, it is a valuable component of a wide variety of useful and reliable hitches, bends, and knots. Two successive half hitches tied around an object makes up the common clove hitch. Two successive half hitches tied around the standing part of a rope is known as two half-hitches or double half hitch. One instance where a half hitch stands on its own without additional embellishment is when added to a timber hitch to help stabilize a load in the direction of pull. A timber hitch is tied on the far end of the load to bind it securely and a half hitch made at the forward end to serve as a guide for the rope. In this instance, the half hitch combined with a timber hitch is known as a killick hitch or kelleg hitch. The knot is attractive to the eye and so is used decoratively for French whipping which is also known as ''half hitch whipping''. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nylon
Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from petroleum, that can be melt-processed into fibers, films, or shapes. Nylon polymers can be mixed with a wide variety of additives to achieve many property variations. Nylon polymers have found significant commercial applications in fabric and fibers (apparel, flooring and rubber reinforcement), in shapes (molded parts for cars, electrical equipment, etc.), and in films (mostly for food packaging). History DuPont and the invention of nylon Researchers at DuPont began developing cellulose based fibers, culminating in the synthetic fiber rayon. DuPont's experience with rayon was an important precursor to its development and marketing of nylon. DuPont's invention of nylon spanned an eleven-year period, ranging from the initial research pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyolefin
A polyolefin is a type of polymer with the general formula (CH2CHR)n where R is an alkyl group. They are usually derived from a small set of simple olefins (alkenes). Dominant in a commercial sense are polyethylene and polypropylene. More specialized polyolefins include polyisobutylene and polymethylpentene. They are all colorless or white oils or solids. Many copolymers are known, such as polybutene, which derives from a mixture of different butene isomers. The name of each polyolefin indicates the olefin from which it is prepared; for example, polyethylene is derived from ethylene, and polymethylpentene is derived from 4-methyl-1-pentene. Polyolefins are not olefins themselves because the double bond of each olefin monomer is opened in order to form the polymer. Monomers having more than one double bond such as butadiene and isoprene yield polymers that contain double bonds ( polybutadiene and polyisoprene) and are usually not considered polyolefins. Polyolefins are the foundat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ProKennex
ProKennex is a Taiwanese manufacturer of racquet sports equipment for tennis, squash, badminton, racquetball, and pickleball. The company enjoyed wide global distribution in the 1980s, when manufacturing in Taiwan was booming due to domestic economic conditions. Parent company Kunnan Enterprise Ltd. has faced financial difficulties since the mid 1990s, leading to a contraction of the ProKennex name globally. Today, the company focuses on a niche set of consumers interested in technology advancements in racquet sports. The company focuses on this aspect of its products by promoting itself as a "science and design company", rather than a standard racket manufacturer. History The origins of the company began in 1965 when Lo Kunnan, the son of a plastic toy gun manufacturer, began producing wooden badminton racquets in the backyard of his father's house. In 1968, Lo moved on to producing wooden tennis racquets, followed by aluminum racquets in 1973. In 1978, Lo launched sporting go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yonex
() is a Japanese sports equipment manufacturing company. Yonex produces equipment and apparel for tennis, badminton, golf, and running. Its range of products manufactured and commercialised includes equipment for badminton and tennis (rackets, shuttlecocks, balls, bags) and golf (clubs, bags). Yonex also produces athletic shoes and apparel including t-shirts, jackets, skirts, shorts, hoodies, leggings and hats. History The company was founded in 1946 by Minoru Yoneyama as a producer of wooden floats for fishing nets. The company was later forced out of this market because of the invention of plastic floats. This led to a commitment by Yoneyama to never again be left behind by technological advancements. In 1957, Yoneyama began to make badminton racquets for other brands. By 1961, the first Yoneyama-branded racquet was introduced, and within another two years an export company was created for the worldwide distribution. After the company began to make aluminium badminton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennis Elbow
Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is a condition in which the outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset of symptoms is generally gradual although they can seem sudden and be misinterpreted as an injury. Golfer's elbow is a similar condition that affects the inside of the elbow. Enthesopathies are idiopathic, meaning science has not yet determined the cause. Enthesopathies are most common in middle age (ages 35 to 60). It is often stated that the condition is caused by excessive use of the muscles of the back of the forearm, but this is not supported by experimental evidence and is a common misinterpretation or unhelpful thought about symptoms. It may be associated with work or sports, classically racquet sports, but most people with the condition are not exposed to these activities. The diagnosis is based on the symptoms and examination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
