1.
Ball
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A ball is a round object with various uses. It is used in games, where the play of the game follows the state of the ball as it is hit. Balls can also be used for activities, such as catch, marbles. Balls made from hard-wearing materials are used in engineering applications to very low friction bearings. Black-powder weapons use stone and metal balls as projectiles, although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus. The Spanish were the first Europeans to see bouncing rubber balls which were employed most notably in the Mesoamerican ballgame, balls used in various sports in other parts of the world prior to Columbus were made from other materials such as animal bladders or skins, stuffed with various materials. As balls are one of the most familiar spherical objects to humans, no Old English representative of any of these is known. If ball- was native in Germanic, it may have been a cognate with the Latin foll-is in sense of a blown up or inflated. In the later Middle English spelling balle the word coincided graphically with the French balle ball, French balle is assumed to be of Germanic origin, itself, however. In Ancient Greek the word πάλλα for ball is attested besides the word σφαίρα, a ball, as the essential feature in many forms of gameplay requiring physical exertion, must date from the very earliest times. A rolling object appeals not only to a baby but to a kitten. Some form of game with a ball is found portrayed on Egyptian monuments, in Homer, Nausicaa was playing at ball with her maidens when Odysseus first saw her in the land of the Phaeacians. And Halios and Laodamas performed before Alcinous and Odysseus with ball play, of regular rules for the playing of ball games, little trace remains, if there were any such. Pollux mentions a game called episkyros, which has often been looked on as the origin of football and it seems to have been played by two sides, arranged in lines, how far there was any form of goal seems uncertain. Among the Romans, ball games were looked upon as an adjunct to the bath, and were graduated to the age and health of the bathers and this was struck from player to player, who wore a kind of gauntlet on the arm. These games are known to us through the Romans, though the names are Greek, the various modern games played with a ball or balls and subject to rules are treated under their various names, such as polo, cricket, football, etc. Several sports use a ball in the shape of a prolate spheroid, Ball Buckminster Fullerene Football Kickball Marbles Penny floater Prisoner Ball Shuttlecock Super Ball
2.
Shuttlecock
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A shuttlecock is a high-drag projectile used in the sport of badminton. The name is from the Victorian times, when Badminton was first discovered and it has an open conical shape, the cone is formed from 16 or so overlapping feathers, usually goose or duck, embedded into a rounded cork base. The cork is covered with thin leather, to ensure that shuttlecocks rotate consistently, only feathers from the birds left wings are used. The shuttlecocks shape makes it extremely aerodynamically stable, regardless of initial orientation, it will turn to fly cork first, and remain in the cork-first orientation. The name shuttlecock is frequently shortened to shuttle, the feathers are brittle, shuttlecocks break easily and often need to be replaced several times during a game. For this reason, synthetic shuttlecocks have been developed that replace the feathers with a plastic skirt, players often refer to synthetic shuttlecocks as plastics and feathered shuttlecocks as feathers. Feather shuttles need to be properly humidified for at least 4 hours prior to play in order to fly the distance at the proper speed. Properly humidified feathers flex during play, enhancing the speed change. Dry feathers are brittle and break easily, causing the shuttle to wobble, saturated feathers are mushy, making the feather cone narrow too much when strongly hit, which causes the shuttle to fly overly far and fast. Humidification boxes are used, but a simple moist sponge inserted in the feather end of the closed shuttle tube will work nicely. Water should never touch the cork of the shuttle, shuttles are tested prior to play to make sure they fly true and at the proper speed, and cover the proper distance. Different weights of shuttles are used to compensate for atmospheric conditions. Both humidity and height above sea level affect shuttle flight, the cost of good quality feathers is similar to that of good quality plastics, but plastics are far more durable, typically lasting many matches without any impairment to their flight. Shuttles are easily damaged and should be replaced every three or four games, and sooner if they are damaged and do not fly straight and this interferes with the game, as the impairment on the flight of the shuttle may misdirect the direction of the shuttlecock. Most experienced and skillful players greatly prefer feathers, and serious tournaments or leagues are played using feather shuttlecocks of the highest quality. Experienced players generally prefer the feel of feathered shuttlecocks and assert that they are able to control the flight of feathers better than that of plastics, in Asia, where feather shuttlecocks are more affordable than in Europe and North America, plastic shuttlecocks are hardly used at all. The playing characteristics of plastics and feathers are substantially different, plastics fly more slowly on initial impact, but slow down less towards the end of their flight. While feathers tend to drop straight down on a shot, plastics never quite return to a straight drop
3.
Squash (sport)
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Squash is a racket sport played by two or four players in a four-walled court with a small, hollow rubber ball. The players must alternate in striking the ball with their racket, the game was formerly called squash rackets, a reference to the squashable soft ball used in the game. The governing body of Squash, the World Squash Federation is recognised by the International Olympic Committee, supporters continue to lobby for its incorporation in a future Olympic program. The use of stringed rackets is shared with tennis, which dates from the sixteenth century. In rackets, instead of hitting over a net as in such as tennis. Squash was invented in Harrow School out of the older game rackets around 1830 before the spread to other schools. The first courts built at this school were rather dangerous because they were near water pipes, buttresses, chimneys, the school soon built four outside courts. Natural rubber was the material of choice for the ball, students modified their rackets to have a smaller reach to play in these cramped conditions. The rackets have changed in a way to those used in tennis. Squash rackets used to be out of laminated timber. In the 1980s, construction shifted to materials with small additions of components like Kevlar, boron. Natural gut strings were replaced with synthetic strings. In the 19th century the increased in popularity with various schools, clubs and even private citizens building squash courts. The first squash court in North America appeared at St. Pauls School in Concord, in 1904 in Philadelphia, Pennsylvania, the earliest national association of squash in the world was formed as the United States Squash rackets Association, now known as U. S. Squash. In April 1907 the Tennis, rackets & Fives Association set up a sub committee to set standards for squash, then the sport soon formed, combining the three sports together called “Squash”. In 1912, the RMS Titanic had a court in first class. The 1st-Class Squash Court was situated on G-Deck and the Spectators Viewing Gallery was on the deck above on F-Deck, to use the Court cost 50 cents in 1912. Passengers could use the court for 1 hour unless others were waiting, standard rackets are governed by the rules of the game
4.
Tennis
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Tennis is a racket sport that can be played individually against a single opponent or between two teams of two players each. Each player uses a racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net. The object of the game is to play the ball in such a way that the opponent is not able to play a valid return, the player who is unable to return the ball will not gain a point, while the opposite player will. Tennis is an Olympic sport and is played at all levels of society, the sport can be played by anyone who can hold a racket, including wheelchair users. The modern game of tennis originated in Birmingham, England, in the late 19th century as lawn tennis and it had close connections both to various field games such as croquet and bowls as well as to the older racket sport of real tennis. The rules of tennis have changed little since the 1890s, two exceptions are that from 1908 to 1961 the server had to keep one foot on the ground at all times, and the adoption of the tiebreak in the 1970s. Tennis is played by millions of players and is also a popular worldwide spectator sport. Historians believe that the ancient origin lay in 12th century northern France. Louis X of France was a player of jeu de paume, which evolved into real tennis. Louis was unhappy with playing tennis outdoors and accordingly had indoor, in due course this design spread across royal palaces all over Europe. Because of the accounts of his death, Louis X is historys first tennis player known by name. Another of the enthusiasts of the game was King Charles V of France. It wasnt until the 16th century that rackets came into use, and the game began to be called tennis, from the French term tenez, an interjection used as a call from the server to his opponent. It was popular in England and France, although the game was played indoors where the ball could be hit off the wall. Henry VIII of England was a big fan of this game, during the 18th century and early 19th century, as real tennis declined, new racket sports emerged in England. This in turn led to the codification of rules for many sports, including lawn tennis, most football codes, lawn bowls. In 1872, along with two doctors, they founded the worlds first tennis club in Leamington Spa. Evans, turfgrass agronomist, Sports historians all agree that deserves much of the credit for the development of modern tennis, according to Honor Godfrey, museum curator at Wimbledon, Wingfield popularized this game enormously
5.
Racquetball
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Racquetball is a racquet sport played with a hollow rubber ball in an indoor or outdoor court. Joseph Sobek is credited with inventing the sport of racquetball in 1950, adding a stringed racquet to paddleball in order to increase velocity. Unlike most racquet sports, such as tennis and badminton, there is no net to hit the ball over, also, the courts walls, floor, and ceiling are legal playing surfaces, with the exception of court-specific designated hinders being out-of-bounds. Racquetball is very similar to 40×20 American handball, which is played in many countries and it is also very similar to the British sport Squash 57, which was called racketball before 2016. Joe Sobek is credited with inventing the sport of racquetball in the New Britain, Connecticut YMCA, a professional tennis and American handball player, Sobek sought a fast-paced sport that was easy to learn and play. He designed the first strung paddle, devised a set of rules, based on those of squash, handball, and paddleball, in February 1952 Sobek founded the National Paddle Rackets Association, codified the rules, and had them printed as a booklet. That same year, the IRA assumed the national championship from the NPRA, in 1974, the IRA organized the first professional tournament, and is a founding member of the International Racquetball Federation. Eventually, the IRA became the American Amateur Racquetball Association, in late 1995, in 2003, the USRA again renamed itself to USA Racquetball, to mirror other Olympic sports associations, even if Racquetball is not an Olympic sport. Kendler used his publication ACE to promote both handball and racquetball, starting in the 1970s, and aided by the fitness boom of that decade, the sports popularity increased to an estimated 3.1 million players by 1974. Consequent to increased demand, racquetball clubs and courts were founded and built, since then, the number of has remained steady, an estimated 5.6 million players. In 1976, Ian D. W. Wright created the sport of racketball based on U. S. racquetball, British racketball is played in a 32-foot long by 21-foot wide squash court, using a smaller, less dynamic ball than the American racquetball. In racketball, the ceiling is out-of-bounds, the racketball is served after a bounce on the floor then struck into play with the racket. Scoring is like squash with point-a-rally scoring of up to 11 points, the British Racketball Association was formed on 13 February 1984, and confirmed by the English Sports Council as the sports governing body on 30 October 1984. The first National Racketball Championship was held in London on 1 December 1984, the sport is now played in countries where squash is played, Australia, Bermuda, France, Germany, Malaysia, the Netherlands, New Zealand, South Africa, Argentina, Ireland and Sweden. Currently, racketball also is played in parts of North America, in 1988, the British Racketball Association merged with the Squash Rackets Association. England Squash & Racketball is now recognised by Sport England as the English national governing body for the sports of squash, Racquetball The International Racquetball Federation governs the World Racquetball Championships, which were first held in 1981 in conjunction with the first World Games. The second World Championships were played in 1984, and since then have been held biennially in August, players from the United States have won the most World Championship titles. Racquetball has been included in the World Games on five occasions,1981,1989,1993,2009 and 2013, Racquetball has been included in the Pan American Games in 1995,1999,2003,2011 and 2015
6.
Badminton
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Badminton is a racquet sport played using racquets to hit a shuttlecock across a net. Although it may be played with teams, the most common forms of the game are singles and doubles. Badminton is often played as an outdoor activity in a yard or on a beach. Points are scored by striking the shuttlecock with the racquet and landing it within the opposing half of the court. Each side may only strike the shuttlecock once before it passes over the net, play ends once the shuttlecock has struck the floor or if a fault has been called by the umpire, service judge, or the opposing side. The shuttlecock is a feathered or plastic projectile which flies differently from the used in many other sports. In particular, the feathers create much higher drag, causing the shuttlecock to decelerate more rapidly, shuttlecocks also have a high top speed compared to the balls in other racquet sports. The game developed in British India from the game of battledore. European play came to be dominated by Denmark but the game has very popular in Asia. Since 1992, badminton has been a Summer Olympic sport with five events, mens singles, womens singles, mens doubles, womens doubles, at high levels of play, the sport demands excellent fitness, players require aerobic stamina, agility, strength, speed, and precision. It is also a sport, requiring good motor coordination. The name derives from the Duke of Beauforts Badminton House in Gloucestershire, as early as 1860, a London toy dealer named Isaac Spratt published a booklet titled Badminton Battledore—A New Game but unfortunately no copy has survived. An 1863 article in The Cornhill Magazine describes badminton as battledore and shuttlecock played with sides, the game may have originally developed among expatriate officers in British India, where it was very popular by the 1870s. Early on, the game was known as Poona or Poonah after the garrison town of Pune, where it was particularly popular. By 1875, returning officers had started a club in Folkestone. Initially, the sport was played with sides ranging from 1–4 players, the shuttlecocks were coated with India rubber and, in outdoor play, sometimes weighted with lead. Although the depth of the net was of no consequence, it was preferred that it should reach the ground, the sport was played under the Pune rules until 1887, when the J. H. E. Hart of the Bath Badminton Club drew up revised regulations, in 1890, Hart and Bagnel Wild again revised the rules
7.
Engineered wood
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These products are engineered to precise design specifications which are tested to meet national or international standards. Engineered wood products are used in a variety of applications, from construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in building projects. Typically, engineered products are made from the same hardwoods and softwoods used to manufacture lumber. Sawmill scraps and other wood waste can be used for engineered wood composed of particles or fibers. Some engineered wood products, like oriented strand board, can use trees from the poplar family, flat pack furniture is typically made out of man-made wood due to its low manufacturing costs and its low weight, making it easy to transport. Plywood, wood panel, is sometimes called the original engineered wood product. Plywood is manufactured from sheets of cross-laminated veneer and bonded under heat and pressure with durable, by alternating the grain direction of the veneers from layer to layer, or “cross-orienting”, panel strength and stiffness in both directions are maximized. Other structural wood panels include oriented strand board and structural composite panels, particle board is manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other suitable binder, which is pressed and extruded. Oriented strand board, also known as flakeboard, waferboard, or chipboard, is similar, particle board is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when cost is more important than strength and appearance. A major disadvantage of particleboard is that it is prone to expansion and discoloration due to moisture. The individual layers are cross-oriented to provide strength and stiffness to the panel, produced in huge, continuous mats, OSB is a solid panel product of consistent quality with no laps, gaps or voids. Glulam can also be produced in curved shapes, offering extensive design flexibility, Laminated veneer lumber is produced by bonding thin wood veneers together in a large billet. The grain of all veneers in the LVL billet is parallel to the long direction, the resulting product features enhanced mechanical properties and dimensional stability that offer a broader range in product width, depth and length than conventional lumber. Cross-Laminated Timber is a versatile multi-layered panel made of lumber, each layer of boards is placed cross-wise to adjacent layers for increased rigidity and strength. CLT can be used for long spans and all assemblies, e. g. floors, CLT has the advantage of faster construction times as the panels are manufactured and finished off site and supplied ready to fit and screw together as a flat pack assembly project. Parallel strand lumber consists of long veneer strands laid in parallel formation, PSL is a member of the structural composite lumber family of engineered wood products. Laminated strand lumber and oriented strand lumber are manufactured from flaked wood strands that have a high length-to-thickness ratio, combined with an adhesive, the strands are oriented and formed into a large mat or billet and pressed
8.
Catgut
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Catgut is a type of cord that is prepared from the natural fibre found in the walls of animal intestines. Catgut makers usually use sheep or goat intestines, but occasionally use the intestines of cattle, hogs, horses, mules, despite the name, catgut manufacturers do not use cat intestines. The word catgut may have been an abbreviation of the word cattlegut, alternatively, it may derive by folk etymology from kitgut or kitstring—the word kit, meaning fiddle, having at some point been confused with the word kit for a young cat. Most musical instruments produced today use strings with cores made of other materials, many acoustic guitarists moved away from gut strings in the early 1900s when the C. F. Martin & Company introduced steel strings, which gave greater volume to the guitar. The demand for steel came from players, who couldnt make themselves heard clearly without it. Within a few years the majority of Martin guitars were made with steel strings to accommodate the demand, after World War II, most classical and flamenco guitarists switched from catgut to the new nylon strings for their greater smoothness, durability, and stability of intonation. Before 1900, the best strings for musical instruments were reputedly from Italy, musicians believed the best were from Naples, though Rome and other Italian cities also produced excellent strings. Today high quality gut strings are produced mostly in Italy, Germany, and they are also made elsewhere, for example in India and Morocco, for local use. Catgut suture was once a widely used material in surgical settings, there is debate about whether to continue using catgut in a medical setting, since cotton is usually cheaper and wounds closed with either cotton or synthetic threads are less prone to infection. Catgut sutures remain in use in developing countries where they are less expensive. Natural gut is still used as a string in tennis racquets. To prepare catgut, workers clean the small intestines, free them from fat, then they scrape off the external membrane with a blunt knife, and steep the intestines again for some time in potassium hydroxide. Then they smooth and equalize the intestines by drawing them out, lean animals yield the toughest gut. Next, they twist the prepared gut strands together to make string, string diameter is determined by the thickness of the individual guts, and by the number used. A thin string, such as a violin E, uses three or four guts, whereas a double bass string may use twenty or more. After twisting and drying, workers polish the strings to the required diameter, before the twentieth century, the strings were simply rubbed with an abrasive to smooth them. Today they are ground down to the desired diameter using a centerless grinder. After drying and polishing, workers bleach and disinfect the strings using sulfur dioxide, dye them if necessary, notes Sources This article incorporates text from a publication now in the public domain, Chisholm, Hugh, ed. Catgut
9.
Real tennis
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Real tennis – one of several games sometimes called the sport of kings – is the original racquet sport from which the modern game of lawn tennis is derived. It is also known as tennis in the United States, formerly royal tennis in England and Australia. The term real was first used by journalists in the early 20th century as a retronym to distinguish the ancient game from modern lawn tennis, Real tennis is still played on about 43 surviving courts in the United Kingdom, Australia, the United States and France. Despite a documented history of courts existing in the German states from the 17th century, the sport is supported and governed by various organizations around the world. The rules and scoring are similar to those of tennis, which derives from real tennis. A match is typically best of three sets, except for the open tournaments, in which matches are best of five sets for men. Unlike the latex-based technology underlying the modern lawn-tennis ball, the game uses a cork-based ball very close in design to the original balls used in the game. The balls are white, but around the end of the 20th century optic yellow was introduced for improved visibility. The balls are much less bouncy than lawn tennis balls, the 27-inch short, asymmetrical racquets are made of wood and use very tight nylon strings to cope with the heavy balls. The racquet head is shaped to make it easier to strike close to the floor or in corners. There are two companies in the world hand-crafting these racquets, Grays of Cambridge and Gold Leaf Athletics, there are two basic designs in existence today - jeu quarré which is an older design and jeu à dedans. The court at Falkland Palace is a jeu quarré design which unlike jeu à dedans court lacks a tambour, the more common real tennis court is a very substantial building. There are no dimensions for courts. Most are about 110 by 39 feet above the penthouses, and about 96 by 32 feet on the playing floor and they are doubly asymmetric, each end of the court differs in shape from the other, and the left and right sides of the court are also different. There are numerous and widely varying styles of service and these are given descriptive names to distinguish them – examples are railroad, bobble, poop, piqué, boomerang, and giraffe. The game has many other complexities, for instance, when the ball bounces twice on the floor at the service end, the serving player does not generally lose the point. A chase can also be called at the end, but only on the half of that end nearest the net. Additionally, a player can gain the advantage of serving only through skillful play and this is in stark contrast to lawn tennis, where players alternately serve and receive entire games
10.
Rackets (sport)
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Rackets or racquets is an indoor racket sport played in the United Kingdom, Ireland, United States, and Canada. The sport is called hard rackets, possibly to distinguish it from the related sport of squash. Historians generally assert that rackets began as an 18th-century pastime in Londons Kings Bench, the prisoners modified the game of fives by using tennis rackets to speed up the action. They played against the wall, sometimes at a corner to add a sidewall to the game. Rackets then became popular outside the prison, played in alleys behind pubs and it spread to schools, first using school walls, and later with proper four-wall courts being specially constructed for the game. The lithograph at right from the late 1700s shows school boys hitting up outside the Harrow School Old School buildings. Eglinton Castle has a Racket Hall which is first shown on the 1860 OS map, but estate records show that it was shortly after 1839. The floor is of granite slabs, now hidden by the wooden floor. It is the very first covered racket court and is now the oldest surviving court in the world and it has been restored as a racket hall, but used as an exhibition area. Some private clubs also built courts, along with real tennis and badminton, rackets was used as an inspiration for the game of lawn tennis, invented in 1873 by Walter Clopton Wingfield. A vacant rackets court built into the University of Chicagos Stagg Field served as the location of the first artificial nuclear chain reaction on December 2,1942, the Stagg Field court is often mistakenly identified as having been a squash rackets court. Rackets was part of the 1908 Summer Olympics program and was played at the Princes Club in London, after the second world war rackets saw a drop in popularity resulting in the closure of some courts and others suffering from a lack of maintenance. Dick Bridgeman, an advocate for the sport established what was then the Dick Bridgeman Tennis, the foundation sought donations to support young professionals thereby ensuring the future of the game. Now known as simply The Tennis and Racquets Foundation, it continues to raise money for young professionals raising the profile of rackets worldwide, the Book of Racquets was published by J. R. Atkins in 1872. It was reprinted to commemorate the 1981 World Rackets Challenge Match between W. J. C, surtees and J. A. N. Prenn as a limited edition of 250 copies. Rackets is played in a 30 by 60 feet enclosed court, singles and doubles are played on the same court. The walls and floor of the court are made of stone or concrete and are generally dark in colour to contrast with the white ball. A player uses 30. 5-inch wooden racket, known as a bat, a good stroke must touch the front wall above a 26.5 inches high wooden board before touching the floor
11.
Xare
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Xare is racquet sport, a form of Basque pelota. Equipment includes a racquet and a ball, the ball is not exactly struck, nor is it quite caught—the effect is somewhere in between. The ball is hard, and covered in parchment. The game is played in an indoor court, called a trinquete. For xare, a net is strung across the middle of the trinquete, xare players wear helmets that are similar to those used in cycling
12.
Carbon fiber reinforced polymer
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Carbon fiber reinforced polymer, carbon fiber reinforced plastic or carbon fiber reinforced thermoplastic, is an extremely strong and light fiber-reinforced plastic which contains carbon fibers. The spelling fibre is common in British Commonwealth countries, the binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester or nylon, are sometimes used. The composite may contain other fibers, such as an aramid, aluminium, ultra-high-molecular-weight polyethylene or glass fibers, the properties of the final CFRP product can also be affected by the type of additives introduced to the binding matrix. The most frequent additive is silica, but other such as rubber. The material is referred to as graphite-reinforced polymer or graphite fiber-reinforced polymer. In product advertisements, it is referred to simply as graphite fiber for short. In this case the composite consists of two parts, a matrix and a reinforcement, in CFRP the reinforcement is carbon fiber, which provides the strength. The matrix is usually a resin, such as epoxy. Because CFRP consists of two elements, the material properties depend on these two elements. The reinforcement will give the CFRP its strength and rigidity, measured by stress, unlike isotropic materials like steel and aluminum, CFRP has directional strength properties. The properties of CFRP depend on the layouts of the carbon fiber, the following equation, E c = V m E m + V f E f is valid for composite materials with the fibers oriented in the direction of the applied load. Typical epoxy-based CFRPs exhibit virtually no plasticity, with less than 0. 5% strain to failure, although CFRPs with epoxy have high strength and elastic modulus, the brittle fracture mechanics present unique challenges to engineers in failure detection since failure occurs catastrophically. As such, recent efforts to toughen CFRPs include modifying the existing epoxy material, One such material with high promise is PEEK, which exhibits an order of magnitude greater toughness with similar elastic modulus and tensile strength. However, PEEK is much more difficult to process and more expensive, despite its high initial strength-to-weight ratio, a design limitation of CFRP is its lack of a definable fatigue endurance limit. This means, theoretically, that stress cycle failure cannot be ruled out, environmental effects such as temperature and humidity can have profound effects on the polymer-based composites, including most CFRPs. While the carbon fibers themselves are not affected by the moisture diffusing into the material, the carbon fibers can cause galvanic corrosion when CRP parts are attached to aluminum. The primary element of CFRP is a filament, this is produced from a precursor polymer such as polyacrylonitrile, rayon. Precursor compositions and mechanical processes used during spinning filament yarns may vary among manufacturers, after drawing or spinning, the polymer filament yarns are then heated to drive off non-carbon atoms, producing the final carbon fiber
13.
Fiberglass
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Fiberglass is a type of fiber-reinforced plastic where the reinforcement fiber is specifically glass fiber. The glass fiber may be arranged, flattened into a sheet. The plastic matrix may be a polymer matrix – most often based on thermosetting polymers such as epoxy, polyester resin. The glass fibers are made of various types of glass depending upon the fiberglass use and these glasses all contain silica or silicate, with varying amounts of oxides of calcium, magnesium, and sometimes boron. To be used in fiberglass, glass fibers have to be made very low levels of defects. Fiberglass is a lightweight material and is used for many products. Although it is not as strong and stiff as composites based on fiber, it is less brittle. Its bulk strength and weight are also better than many metals, other common names for fiberglass are glass-reinforced plastic, glass-fiber reinforced plastic or GFK. Because glass fiber itself is referred to as fiberglass, the composite is also called fiberglass reinforced plastic. This article will adopt the convention that fiberglass refers to the glass fiber reinforced composite material. A patent for this method of producing glass wool was first applied for in 1933, Owens joined with the Corning company in 1935 and the method was adapted by Owens Corning to produce its patented fibreglas in 1936. Originally, fibreglas was a wool with fibers entrapping a great deal of gas, making it useful as an insulator. A suitable resin for combining the fibreglass with a plastic to produce a material was developed in 1936 by du Pont. The first ancestor of modern polyester resins is Cyanamids resin of 1942, peroxide curing systems were used by then. With the combination of fiberglass and resin the gas content of the material was replaced by plastic and this reduced the insulation properties to values typical of the plastic, but now for the first time the composite showed great strength and promise as a structural and building material. Confusingly, many glass fiber composites continued to be called fiberglass, ray Greene of Owens Corning is credited with producing the first composite boat in 1937, but did not proceed further at the time due to the brittle nature of the plastic used. In 1939 Russia was reported to have constructed a boat of plastic materials. The first car to have a body was a 1946 prototype of the Stout Scarab
14.
Titanium
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Titanium is a chemical element with symbol Ti and atomic number 22. It is a transition metal with a silver color, low density. Titanium is resistant to corrosion in sea water, aqua regia, titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, and it is named by Martin Heinrich Klaproth for the Titans of Greek mythology. The metal is extracted from its principal mineral ores by the Kroll, the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride, a component of smoke screens and catalysts, and titanium trichloride, the two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is as strong as some steels, there are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the number of valence electrons and are in the same group in the periodic table. As a metal, titanium is recognized for its high strength-to-weight ratio and it is a strong metal with low density that is quite ductile, lustrous, and metallic-white in color. The relatively high melting point makes it useful as a refractory metal and it is paramagnetic and has fairly low electrical and thermal conductivity. Commercial grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, titanium is 60% denser than aluminium, but more than twice as strong as the most commonly used 6061-T6 aluminium alloy. Certain titanium alloys achieve tensile strengths of over 1400 MPa, however, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel, it is non-magnetic, machining requires precautions, because the material might gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a limit that guarantees longevity in some applications. The metal is an allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases dramatically as it is heated to this transition temperature but then falls, similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but metastable at ambient pressures. This phase is usually hexagonal or trigonal and can be considered to be due to a soft longitudinal acoustic phonon of the β phase causing collapse of planes of atoms, like aluminium and magnesium, titanium metal and its alloys oxidize immediately upon exposure to air. Titanium readily reacts with oxygen at 1,200 °C in air and it is, however, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation. When it first forms, this layer is only 1–2 nm thick but continues to grow slowly
15.
Ceramic
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A ceramic is an inorganic, non-metallic, solid material comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds. This article gives an overview of ceramic materials from the point of view of materials science, the crystallinity of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous. Most often, fired ceramics are either vitrified or semi-vitrified as is the case with earthenware, stoneware, varying crystallinity and electron consumption in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators. With such a range of possible options for the composition/structure of a ceramic, the breadth of the subject is vast. Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family. The earliest ceramics made by humans were pottery objects or figurines made from clay, either by itself or mixed with materials like silica, hardened, sintered. Later ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, ceramics now include domestic, industrial and building products, as well as a wide range of ceramic art. In the 20th century, new materials were developed for use in advanced ceramic engineering. The word ceramic comes from the Greek word κεραμικός, of pottery or for pottery, from κέραμος, potters clay, tile, the earliest known mention of the root ceram- is the Mycenaean Greek ke-ra-me-we, workers of ceramics, written in Linear B syllabic script. The word ceramic may be used as an adjective to describe a material, product or process, or it may be used as a noun, either singular, or, more commonly, as the plural noun ceramics. A ceramic material is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material, some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and they withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C. Glass is often not considered a ceramic because of its amorphous character. However, glassmaking involves several steps of the process and its mechanical properties are similar to ceramic materials. Traditional ceramic raw materials include minerals such as kaolinite, whereas more recent materials include aluminium oxide. The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide, both are valued for their abrasion resistance, and hence find use in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are used in the medicine, electrical, electronics industries. Crystalline ceramic materials are not amenable to a range of processing
16.
Nylon
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Nylon is a generic designation for a family of synthetic polymers, more specifically aliphatic or semi-aromatic polyamides. They can be melt-processed into fibers, films or shapes, the first example of nylon was produced on February 28,1935, by Wallace Carothers at DuPonts research facility at the DuPont Experimental Station. Nylon polymers have significant commercial applications in fibers, in shapes. Nylon is made of repeating units linked by bonds and is a type of polyamide and is frequently referred to as such. Nylon was the first commercially successful synthetic thermoplastic polymer, commercially, nylon polymer is made by reacting monomers which are either lactams, acid/amines or stoichiometric mixtures of diamines and diacids. Mixtures of these can be polymerized together to make copolymers, Nylon polymers can be mixed with a wide variety of additives to achieve many different property variations. Nylon was invented accidentally by Julian W. Hill, a chemist for DuPont under Wallace Carotherss supervision and it was only given this name at the 1939 New York Worlds Fair. The patents were owned by DuPont, Nylon was intended to be a synthetic replacement for silk and substituted for it in many different products after silk became scarce during World War II. It replaced silk in military applications such as parachutes and flak vests, after initial commercialization of nylon as a fiber, applications in the form of shapes and films were also developed. The main market for nylon shapes now is in auto components, in 1940, John W. Eckelberry of DuPont stated that the letters nyl were arbitrary and the on was copied from the suffixes of other fibers such as cotton and rayon. A later publication by DuPont explained that the name was intended to be No-Run. Since the products were not really run-proof, the vowels were swapped to produce nuron, for clarity in pronunciation, the i was changed to y. Most nylons are made from the reaction of an acid with a diamine or a lactam or amino acid with itself. In the first case, the structure is so-called ABAB similar to polyesters and polyurethanes, in the second case, the repeating unit corresponds to the single monomer. It is difficult to get the proportions exactly correct, and deviations can lead to termination at molecular weights less than a desirable 10,000 daltons. To overcome this problem, a crystalline, solid nylon salt can be formed at room temperature, using an exact 1,1 ratio of the acid, the salt is crystallized to purify it and obtain the desired precise stoichiometry. Heated to 285 °C, the salt reacts to form nylon polymer with the production of water, Wallace Carothers at DuPont patented nylon 66, but overlooked the possibility to use lactams. That synthetic route was developed by Paul Schlack at IG Farben, leading to nylon 6, the peptide bond within the caprolactam is broken with the exposed active groups on each side being incorporated into two new bonds as the monomer becomes part of the polymer backbone
17.
Polyamide
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A polyamide is a macromolecule with repeating units linked by amide bonds. Polyamides occur both naturally and artificially, examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made through step-growth polymerization or solid-phase synthesis yielding materials such as nylons, aramids, synthetic polyamides are commonly used in textiles, automotive applications, carpets and sportswear due to their high durability and strength. The transportation manufacturing industry is the consumer, accounting for 35% of polyamide consumption. Polymers of amino acids are known as polypeptides or proteins, the monomers can be amides themselves, α, ω-amino acids or a stoichiometric mixture of a diamine and a diacid. Both these kinds of precursors give a homopolymer, Polyamides are easily copolymerized, and thus many mixtures of monomers are possible which can in turn lead to many copolymers. Additionally many nylon polymers are miscible with one another allowing the creation of blends, production of polymers requires the repeated joining of two groups to form an amide linkage. In this case this specifically involves amide bonds, and the two involved are an amine group, and a terminal carbonyl component of a functional group. These react to produce a bond, creating a singular amide linkage. This process involves the elimination of other atoms previously part of the functional groups, the carbonyl-component may be part of either a carboxylic acid group or the more reactive acyl halide derivative. The condensation reaction is used to produce nylon polymers in industry. Nylons must specifically include an straight chain monomer, the amide link is produced from an amine group, and a carboxylic acid group. The hydroxyl from the carboxylic acid combines with a hydrogen from the amine, and gives rise to water, as an example of condensation reactions, consider that in living organisms, Amino acids are condensed with one another by an enzyme to form amide linkages. The resulting polyamides are known as proteins or polypeptides, in the diagram below, consider the amino-acids as single aliphatic monomers reacting with identical molecules to form a polyamide, focusing on solely the amine and acid groups. The polymerization reaction with the amine group eliminates hydrogen chloride, the acid chloride route can be used as a laboratory synthesis to avoid heating and obtain an almost instantaneous reaction. The aromatic moiety itself does not participate in reaction, but it does increase the rigidity. In the diagram below, Aramid is made from two different monomers which continuously alternate to form the polymer, Aramid is an aromatic polyamide, Polyamides can also be synthesized from dinitriles using acid catalysis via an application of the Ritter reaction. This method is applicable for preparation of nylon 1,6 from adiponitrile, formaldehyde, additionally, polyamides can be synthesized from glycols and dinitriles using this method as well
18.
Malcolm Whitman
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Malcolm Mal Douglass Whitman was an American tennis player who won three singles titles at the U. S. National Championships. He graduated from The Roxbury Latin School, where he is celebrated as one of its greatest athletes, Whitman was American intercollegiate singles tennis champion in 1896 and doubles champion in 1897 and 1898 as a student at Harvard University. He graduated from Harvard Law School in 1899 and received his bachelor in law degree in 1902, in 1896 Whitman entered his first U. S. National Championships at the Newport Casino and lost in the quarterfinals to Bill Larned. The following year,1897, he again lost in the quarterfinals, Whitman is best known for this hat-trick of singles titles at the U. S. National Championships. Between 1898 and 1900, he stayed undefeated there, in 1901 he did not compete and in the 1902 Championships he lost in the All-Comers final to Englishman Reginald Doherty. According to the Doherty brothers Malcolm Whitman and Bill Larned were at the time the best American singles players and he played on the inaugural American Davis Cup squad in 1900 and beat Englishman Arthur Gore in Boston, MA to help his US team win the trophy. In the 1902 Davis Cup final against Great Britain in Brooklyn, NY he again contributed to his teams win by defeating Joshua Pim, Whitman retired from tennis in 1902 at the age of 25. He was a member of the Executive Committee of the U. S. National Lawn Tennis Association, in 1932 he wrote a book on the origin of tennis titled Tennis - Origins and Mysteries. She died in December 1909 after the birth of their second child, in July 1912 Whitman married Jennie Adeline Crocker but they divorced in 1924. In 1926, Whitman married Lucilla Mara de Vescovi, known as the Countess Mara, in December 1931 his daughter Mary,16, from his second marriage, died of pneumonia. On December 28,1932 Whitman committed suicide by jumping off an apartment building in New York after a nervous breakdown, Malcolm Douglass Whitman, Tennis Origins and Mysteries. With an historical bibliography by Robert W. Henderson, derrydale Press, New York NY1932. Malcolm D. Whitman, Fly Fishing Up to Date, privately printed by The Plimpton Press, Norwood, Mass 1924 Malcolm D. Whitman, writing under the pseudonym Icarus de Plume, The Island of Elcadar Marshall Jones Co. Boston 1921 Malcolm Whitman at the International Tennis Hall of Fame Malcolm Whitman at the International Tennis Federation Malcolm Whitman at the Davis Cup
19.
Flemish
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The term Flemish is used in at least five ways. These are, in order of increasing order, as an informal term meaning Dutch language in Belgium. Linguists tend to avoid the use of the term Flemish in this context, as a synonym for the so-called intermediate speech known as tussentaal. to denote any of the local Dutch dialects anywhere in the Flanders region. There are four principal Dutch dialects in the Flemish region, Brabantian, East Flemish, the latter two are sometimes considered separate languages. Despite its name, Brabantian is the dominant contributor to the Flemish Dutch tussentaal, the combined region, culture, and people of Dutch-speaking Belgium has come to be known as Flemish. Flemish is also used to refer to one of the languages spoken in the former County of Flanders. Linguistically and formally, Flemish refers to the region, culture, Flemish people speak Dutch in Flanders, the Flemish part of Belgium. Belgian Dutch is slightly different from Dutch spoken in The Netherlands, mainly in pronunciation, lexicon, similar differences exist within other languages, such as English, French, Spanish, and Portuguese. The differences are not significant enough to constitute an individual language, Dutch is the majority language in northern Belgium, being spoken natively by three-fifths of the population. It is one of the three languages of Belgium, together with French and German, and is the only official language of the Flemish Region. The various Dutch dialects spoken in Belgium contain a number of lexical, as in the Netherlands, the pronunciation of Standard Dutch is affected by the native dialect of the speaker. All Dutch dialect groups spoken in Belgium are spoken in adjacent areas of the Netherlands as well, East Flemish forms a continuum with both Brabantic and West Flemish. Standard Dutch is primarily based on the Hollandic dialect and to an extent on Brabantian. Among vowels is the diphthong ou / au, ou as in bout and au as in fauna is realized as in formal situations. In informal situations, the sound tends to be pronounced as or as a monophthong, depending on the dialect, in contrast, these are generally pronounced as in the north and middle parts of the Netherlands. Among consonants, the northern Dutch pronunciation of w is, in some southern Dutch dialects it is or, probably the most obvious difference between northern and southern Dutch is in the sounds spelled ⟨ch⟩ and ⟨g⟩. The sound spelled ⟨ch⟩ is a velar fricative in northern Dutch. ⟨w⟩ realised as ⟨ch⟩ and ⟨g⟩ pronounced as front-velars, not as palatals, Belgian Dutch includes different French loanwords in its vocabulary compared to Netherlands Dutch
20.
Kinetic energy
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In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes, the same amount of work is done by the body in decelerating from its current speed to a state of rest. In classical mechanics, the energy of a non-rotating object of mass m traveling at a speed v is 12 m v 2. In relativistic mechanics, this is an approximation only when v is much less than the speed of light. The standard unit of energy is the joule. The adjective kinetic has its roots in the Greek word κίνησις kinesis, the dichotomy between kinetic energy and potential energy can be traced back to Aristotles concepts of actuality and potentiality. The principle in classical mechanics that E ∝ mv2 was first developed by Gottfried Leibniz and Johann Bernoulli, Willem s Gravesande of the Netherlands provided experimental evidence of this relationship. By dropping weights from different heights into a block of clay, Émilie du Châtelet recognized the implications of the experiment and published an explanation. The terms kinetic energy and work in their present scientific meanings date back to the mid-19th century, early understandings of these ideas can be attributed to Gaspard-Gustave Coriolis, who in 1829 published the paper titled Du Calcul de lEffet des Machines outlining the mathematics of kinetic energy. William Thomson, later Lord Kelvin, is given the credit for coining the term kinetic energy c, energy occurs in many forms, including chemical energy, thermal energy, electromagnetic radiation, gravitational energy, electric energy, elastic energy, nuclear energy, and rest energy. These can be categorized in two classes, potential energy and kinetic energy. Kinetic energy is the movement energy of an object, Kinetic energy can be transferred between objects and transformed into other kinds of energy. Kinetic energy may be best understood by examples that demonstrate how it is transformed to, for example, a cyclist uses chemical energy provided by food to accelerate a bicycle to a chosen speed. On a level surface, this speed can be maintained without further work, except to overcome air resistance, the chemical energy has been converted into kinetic energy, the energy of motion, but the process is not completely efficient and produces heat within the cyclist. The kinetic energy in the moving cyclist and the bicycle can be converted to other forms, for example, the cyclist could encounter a hill just high enough to coast up, so that the bicycle comes to a complete halt at the top. The kinetic energy has now largely converted to gravitational potential energy that can be released by freewheeling down the other side of the hill. Since the bicycle lost some of its energy to friction, it never regains all of its speed without additional pedaling, the energy is not destroyed, it has only been converted to another form by friction
21.
Fraxinus
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Fraxinus /ˈfræksᵻnəs/, English name ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of medium to large trees, mostly deciduous though a few subtropical species are evergreen. The genus is widespread across much of Europe, Asia and North America, the trees common English name, ash, traces back to the Old English æsc, while the generic name originated in Latin. Both words also mean spear in their respective languages, the leaves are opposite, and mostly pinnately compound, simple in a few species. The seeds, popularly known as keys or helicopter seeds, are a type of known as a samara. Rowans or mountain ashes have leaves and buds superficially similar to those of true ashes, species are organized according to phylogenetic analysis. – California ash or two-petal ash Fraxinus anomala Torr, ex S. Watson – singleleaf ash Fraxinus quadrangulata Michx. – blue ash Fraxinus lowellii – Lowell ash Fraxinus trifoliata Section Melioides sensu lato Fraxinus chiisanensis Fraxinus cuspidata Torr. – fragrant ash Fraxinus platypoda Fraxinus spaethiana Lingelsh, – Späths ash Section Melioides sensu stricto Fraxinus uhdei Lingelsh. – Shamel ash or tropical ash Fraxinus latifolia Benth, – Oregon ash Fraxinus papillosa Lingelsh. – Chihuahua ash Fraxinus americana L. – white ash or American ash Fraxinus profunda Bush – pumpkin ash Fraxinus pennsylvanica Marshall – green ash Fraxinus velutina Torr, – velvet ash or Arizona ash Fraxinus berlandieriana DC. – Mexican ash Fraxinus caroliniana Mill, – Carolina ash Fraxinus texensis Sarg. – Texas ash Section Pauciflorae Fraxinus greggii A. ex DC, – Afghan ash Fraxinus dimorpha Section Fraxinus Fraxinus nigra Marshall – black ash Fraxinus mandschurica Rupr. – Manchurian ash Fraxinus holotricha Koehne Fraxinus angustifolia Vahl – narrow-leafed ash Fraxinus angustifolia subsp, oxycarpa – Caucasian ash Claret ash or raywood ash Fraxinus angustifolia subsp. – European ash Fraxinus pallisiae Wilmott – Pallis ash Fraxinus sogdiana Bge Section Ornus Fraxinus griffithii C. B. Clarke – Griffiths ash Fraxinus micrantha Lingelsh, – Chinese ash or Korean ash Fraxinus japonica – Japanese ash Fraxinus longicuspis Fraxinus floribunda Wall. – Himalayan manna ash Fraxinus ornus L. – manna ash or flowering ash Fraxinus bungeana DC, – Bunges ash Fraxinus paxiana Lingelsh. The emerald ash borer is a wood-boring beetle accidentally introduced to North America from eastern Asia via solid wood packing material in the late 1980s to early 1990s and it has killed tens of millions of trees in 15 states in the United States and adjacent Ontario in Canada. It threatens some seven billion ash trees in North America, the public is being cautioned not to transport unfinished wood products, such as firewood, to slow the spread of this insect pest. The disease has infected about 90% of Denmarks ash trees, in 2016, the ash tree was reported as in danger of extinction in Europe
22.
Graphite
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Graphite, archaically referred to as plumbago, is a crystalline form of carbon, a semimetal, a native element mineral, and one of the allotropes of carbon. Graphite is the most stable form of carbon under standard conditions, therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. Highly ordered pyrolytic graphite or more correctly highly oriented pyrolytic graphite refers to graphite with a spread between the graphite sheets of less than 1°. The name graphite fiber is sometimes used to refer to carbon fibers or carbon fiber-reinforced polymer. Graphite occurs in rocks as a result of the reduction of sedimentary carbon compounds during metamorphism. It also occurs in rocks and in meteorites. Minerals associated with graphite include quartz, calcite, micas and tourmaline, in meteorites it occurs with troilite and silicate minerals. Small graphitic crystals in meteoritic iron are called cliftonite, Graphite is not mined in the United States, but U. S. production of synthetic graphite in 2010 was 134 kt valued at $1.07 billion. Graphite has a layered, planar structure, the individual layers are called graphene. In each layer, the atoms are arranged in a honeycomb lattice with separation of 0.142 nm. Atoms in the plane are bonded covalently, with three of the four potential bonding sites satisfied. The fourth electron is free to migrate in the plane, making graphite electrically conductive, however, it does not conduct in a direction at right angles to the plane. Bonding between layers is via weak van der Waals bonds, which allows layers of graphite to be easily separated, the two known forms of graphite, alpha and beta, have very similar physical properties, except for that the graphene layers stack slightly differently. The alpha graphite may be flat or buckled. The alpha form can be converted to the form through mechanical treatment. The acoustic and thermal properties of graphite are highly anisotropic, since phonons propagate quickly along the tightly-bound planes, graphites high thermal stability and electrical and thermal conductivity facilitate its widespread use as electrodes and refractories in high temperature material processing applications. However, in oxygen containing atmospheres graphite readily oxidizes to form CO2 at temperatures of 700 °C, Graphite is an electric conductor, consequently, useful in such applications as arc lamp electrodes. It can conduct electricity due to the vast electron delocalization within the carbon layers and these valence electrons are free to move, so are able to conduct electricity
23.
Kevlar
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Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, this material was first commercially used in the early 1970s as a replacement for steel in racing tires. Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components and it is also used to make modern drumheads that withstand high impact. When used as a material, it is suitable for mooring lines. A similar fiber called Twaron with roughly the same structure was developed by Akzo in the 1970s, commercial production started in 1986. Poly-paraphenylene terephthalamide – branded Kevlar – was invented by Polish-American chemist Stephanie Kwolek while working for DuPont, in 1964, her group began searching for a new lightweight strong fiber to use for light but strong tires. The polymers she had been working with at the time, poly-p-phenylene-terephthalate and polybenzamide, formed liquid crystal while in solution, the solution was cloudy, opalescent upon being stirred, and of low viscosity and usually was thrown away. However, Kwolek persuaded the technician, Charles Smullen, who ran the spinneret, to test her solution and her supervisor and her laboratory director understood the significance of her accidental discovery and a new field of polymer chemistry quickly arose. By 1971, modern Kevlar was introduced, however, Kwolek was not very involved in developing the applications of Kevlar. Kevlar is synthesized in solution from the monomers 1, 4-phenylene-diamine, the result has liquid-crystalline behavior, and mechanical drawing orients the polymer chains in the fibers direction. Hexamethylphosphoramide was the solvent initially used for the polymerization, but for safety reasons, DuPont replaced it by a solution of N-methyl-pyrrolidone, as this process had been patented by Akzo in the production of Twaron, a patent war ensued. Kevlar production is expensive because of the difficulties arising from using concentrated sulfuric acid, needed to keep the water-insoluble polymer in solution during its synthesis and spinning. Several grades of Kevlar are available, Kevlar K-29 – in industrial applications, such as cables, asbestos replacement, brake linings, Kevlar K49 – high modulus used in cable and rope products. When Kevlar is spun, the fiber has a tensile strength of about 3,620 MPa. The polymer owes its high strength to the many inter-chain bonds and these inter-molecular hydrogen bonds form between the carbonyl groups and NH centers. Additional strength is derived from aromatic stacking interactions between adjacent strands, the presence of salts and certain other impurities, especially calcium, could interfere with the strand interactions and care is taken to avoid inclusion in its production. Kevlars structure consists of relatively rigid molecules tend to form mostly planar sheet-like structures rather like silk protein. Kevlar maintains its strength and resilience down to temperatures, in fact
24.
Boron
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Boron is a chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is an element in the Solar system. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds and these are mined industrially as evaporites, such as borax and kernite. The largest known deposits are in Turkey, the largest producer of boron minerals. Elemental boron is a metalloid that is found in small amounts in meteoroids, industrially, very pure boron is produced with difficulty because of refractory contamination by carbon or other elements. Several allotropes of boron exist, amorphous boron is a powder, crystalline boron is silvery to black, extremely hard. The primary use of boron is as boron filaments with applications similar to carbon fibers in some high-strength materials. Boron is primarily used in chemical compounds, about half of all consumption globally, boron is used as an additive in glass fibers of boron-containing fiberglass for insulation and structural materials. The next leading use is in polymers and ceramics in high-strength, lightweight structural, borosilicate glass is desired for its greater strength and thermal shock resistance than ordinary soda lime glass. Boron compounds are used as fertilizers in agriculture and in sodium perborate bleaches, a small amount of boron is used as a dopant in semiconductors, and reagent intermediates in the synthesis of organic fine chemicals. A few boron-containing organic pharmaceuticals are used or are in study, natural boron is composed of two stable isotopes, one of which has a number of uses as a neutron-capturing agent. In biology, borates have low toxicity in mammals, but are toxic to arthropods and are used as insecticides. Boric acid is mildly antimicrobial, and several natural boron-containing organic antibiotics are known, small amounts of boron compounds play a strengthening role in the cell walls of all plants, making boron a necessary plant nutrient. Boron is involved in the metabolism of calcium in both plants and animals and it is considered an essential nutrient for humans, and boron deficiency is implicated in osteoporosis. The word boron was coined from borax, the mineral from which it was isolated, by analogy with carbon, marco Polo brought some glazes back to Italy in the 13th century. Agricola, around 1600, reports the use of borax as a flux in metallurgy, in 1777, boric acid was recognized in the hot springs near Florence, Italy, and became known as sal sedativum, with primarily medical uses. The rare mineral is called sassolite, which is found at Sasso, Sasso was the main source of European borax from 1827 to 1872, when American sources replaced it. Boron compounds were relatively rarely used until the late 1800s when Francis Marion Smiths Pacific Coast Borax Company first popularized and produced them in volume at low cost
25.
Table tennis racket
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A table tennis racket is used by table tennis players. The table tennis racket is usually made from laminated wood covered with rubber on one or two depending on the players grip. Unlike a conventional racket, it does not include strings strung across an open frame, the USA generally uses the term paddle while Europeans and Asians use the term bat and the official ITTF term is racket. Table tennis regulations approved by the International Table Tennis Federation allow different surfaces on each side of the paddle for various amounts of spin or speed, for example, a player may have a spin-heavy rubber on one side of his paddle, and no spin on the other side. The player can flip the racket in play for different types of returns, the player has the right to inspect his opponents racquet before a match to see the type and color. Current rules state that, unless damaged in play, the paddle cannot be exchanged for another at any time during a match. The rubber coating may be of pimpled rubber, with the outward, or it may be composed of a sponge layer. Some paddles are not covered with rubber to make it spin resistant, however, it is illegal to use these types of racquet in competition as they are not approved by the ITTF. Some types of rubbers are also not approved, approved rubbers have the ITTF emblem on the base of the rubber. Choices Players have many choices and variations in rubber sheets on their racquet, although a racquet may be purchased assembled with rubber by the manufacturer, most serious tournament players will use a custom racquet. A player selects a blank blade based on his or her playing style, the type of wood or synthetic layers used to make up the blade will determine the blades speed. The different types of rubber sheets affect the level of spin, speed, racquet construction and new rubber technology contribute significantly to the amount of deviation from the expected ball flight path. Normally, a sheet of rubber is glued to a blade using various table tennis brand glues such as Butterfly, Donic, some glues may work even if it wasnt designed specifically for table tennis, such as Rubber Cement and Tear Mender. The rubber is not removed until it wears out or becomes damaged, in the 1980s, some players developed a new technique with a special glue called speed glue to apply the rubber every time he played. The glue would help provide more spin and speed by providing a catapult effect, speed glue was allowed for the last time in the 2008 Summer Olympics. From the 2012 Summer Olympics onward, the Olympic games banned speed glue, the surface of a racquet will develop a smooth glossy patina with use. The rubber surface needs regular cleaning to retain a high friction surface for ball spin, commercial cleaners or water and soap can be cleaning agents. Sun exposure may damage the rubber
26.
Table tennis
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Table tennis, also known as ping pong, is a sport in which two or four players hit a lightweight ball back and forth across a table using a small bat. The game takes place on a hard table divided by a net, a point is scored when a player fails to return the ball within the rules. Play is fast and demands quick reactions, spinning the ball alters its trajectory and limits an opponents options, giving the hitter a great advantage. Table tennis is governed by the worldwide organization International Table Tennis Federation, ITTF currently includes 220 member associations. The table tennis rules are specified in the ITTF handbook. Table tennis has been an Olympic sport since 1988, with several event categories, from 1988 until 2004, these were mens singles, womens singles, mens doubles and womens doubles. Since 2008, an event has been played instead of the doubles. The sport originated in Victorian England, where it was played among the upper-class as a parlour game. It has been suggested that makeshift versions of the game were developed by British military officers in India in around 1860s or 1870s, who brought it back with them. A row of books stood up along the center of the table as a net and it had several different names, including whiff-whaff. The name ping-pong was in use before British manufacturer J. Jaques & Son Ltd trademarked it in 1901. The name ping-pong then came to describe the game played using the rather expensive Jaquess equipment, a similar situation arose in the United States, where Jaques sold the rights to the ping-pong name to Parker Brothers. Parker Brothers then enforced its trademark for the term in the 1920s making the various associations change their names to table tennis instead of the more common, but trademarked, term. The next major innovation was by James W. Gibb, a British enthusiast of table tennis, who discovered novelty celluloid balls on a trip to the US in 1901 and found them to be ideal for the game. This was followed by E. C. Goode who, in 1901, invented the modern version of the racket by fixing a sheet of pimpled, or stippled, rubber to the wooden blade. Table tennis was growing in popularity by 1901 to the extent that tournaments were being organized, books being written on the subject, in 1921, the Table Tennis Association was founded in Britain, and the International Table Tennis Federation followed in 1926. London hosted the first official World Championships in 1926, in 1933, the United States Table Tennis Association, now called USA Table Tennis, was formed. In the 1930s, Edgar Snow commented in Red Star Over China that the Communist forces in the Chinese Civil War had a passion for the English game of table tennis which he found bizarre
27.
International Table Tennis Federation
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The International Table Tennis Federation is the governing body for all international table tennis associations. The role of the ITTF includes overseeing rules and regulations and seeking technological improvement for the sport of table tennis, the ITTF is responsible for the organization of numerous international competitions, including the World Table Tennis Championships that has continued since 1926. The ITTF was founded in 1926 by William Henry Lawes of Wymondham, the first international tournament was held in January 1926 in Berlin while the first World Table Tennis Championships was held in December 1926 in London. Toward the end of 2000, the ITTF instituted several rules changes aimed at making table tennis more viable as a spectator sport. The older 38 mm balls were replaced by 40 mm balls. This increased the air resistance and effectively slowed down the game. On 29 February 2008, the ITTF announced several changes after an ITTF Executive Meeting in Guangzhou, Guangdong. The new ruling is to encourage associations to develop their own players, the headquarters of the ITTF is in Lausanne, Switzerland. The previous president of the ITTF was Adham Sharara from Canada, the ITTF recognises six continental federations. Each continental federation has a president as its top official and owns its constitution, the following are recognised federations, There are currently 222 member associations within the ITTF. All member associations of the ITTF attend annual general meeting, agendas on changes of the constitution, laws of table tennis, applications for membership etc. are discussed and finalised through votes. Also, the president of ITTF,8 executive vice-presidents, and 32 or less continental representatives are elected at an AGM, the president, executive vice-presidents, and the chairman of the athletes commission compose executive committee. The executive committee, continental representatives and presidents of the six continental federations or their appointees compose the board of directors, the Board manages the work of the ITTF between AGMs. Several committees, commissions, working groups or panels work under the constitution of ITTF or under the Board, unlike the organisations for more popular sports, the ITTF tends to recognise teams from generally unrecognised governing bodies for disputed territory. For example, it recognises the Table Tennis Federation of Kosovo even though Kosovo is excluded from most other sports. It recognised the Peoples Republic of China in 1953 and allowed some basic diplomacy which lead to an opening for U. S. President Richard Nixon, called Ping Pong Diplomacy, in the early 1970s. For ITTF World Title events, a player is eligible to play for his association by registering with the ITTF, if the player chooses to play for a new association, he shall register with the ITTF, through the new association. The player shall not represent the new association before, the table tennis point system was reduced from a 21 to an 11-point scoring system in 2001
28.
Strings (tennis)
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In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a network inside the head of the racquet. The material used in tennis string can significantly affect a players performance, several materials are used to make tennis strings. They vary in terms of elasticity, durability, rebound efficiency, tension holding capability, animal intestine is the most resilient material used to make tennis strings. It has better tension retention than any 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 string and it remains soft at high tensions while other materials tend to stiffen dramatically. Natural gut is very sensitive to different types of weather and those players who use it normally carry several different racquets with different tensions to compensate for this and this may help to offset the high initial cost. The use of a dense string pattern also generally improves the longevity of natural gut and it is this elasticity that makes the fibers useful for tennis string. Sheep intestines have also used for racquet strings in the past. A general name for material is catgut. The first natural gut tennis string was rumored to be manufactured in 1875 by Pierre Babolat, natural gut is usually offered in coated form, to reduce its tendency to unravel, particularly when humid or wet. Synthetic gut is nylon, nearly always composed of a single filament and it is a very inexpensive string to manufacture and is generally the least expensive string to purchase. Small changes from pure nylon are usually found in strings sold as synthetic gut, textured coatings, colorants and the addition of a small amount of Kevlar are the most common changes. Some manufacturers, such as Gosen, label nylon strings with words like sheep, as in sheep intestine, multi-filament strings, known commonly as multis are strings that have more than one filament. They are most commonly made of filaments of nylon, but can incorporate other materials such as polyurethane, Zyex, Vectran, Kevlar. Multi-filament strings offer better elasticity than single filament strings, but usually inferior durability, no multi-filament string holds its tension as well as natural gut, and none of them is as soft. However, in comparison to mono-filament synthetic gut, multi-filament strings can offer a much closer approximation of natural guts performance, the softest multi-filament strings can be made with Zyex and polyolefin, although some of the softest of these strings are no longer on the market. Nylon is the most popular string material for amateur players due to its low cost, wear-resistant coatings for nylon strings are common, especially with multi-filament strings, because the outer filaments tend to break first as the racquet is used
29.
Prince Sports
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Prince Global Sports, LLC, based in Atlanta, Georgia, is a manufacturer and distributor of racket sports equipment, footwear and apparel for tennis, squash and badminton. The company was founded in 1970 by Robert H. McClure of Princeton, New Jersey as a manufacturer of tennis ball machines, howard Head, founder of the Head Ski Company, took tennis lessons following his retirement. He used one of the tennis ball machines made by Prince, Head joined the company in the early 1970s and developed the companys signature oversized tennis racket. Although the Prince Classic aluminum racket was the first oversized racquet to be patented, the company has been owned by a variety of different firms, including at the Benetton Group of Italy and Chesebrough-Ponds, and Nautic Partners, a Providence, Rhode Island-based private equity firm. In July 2012, Authentic Brands Group officially acquired the Prince brand name from Nautic Partners, Prince Global Sports is now operating as a subsidiary of Athletic Brands Holding Company which is majority owned by the Waitt Company. The companys portfolio of brands also includes Ektelon, Viking and Battle, in March 2014, Prince announced that they were moving their headquarters to Atlanta
30.
Yonex
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Yonex Co. Ltd. is a Japanese manufacturer of sporting equipment for badminton, golf, and tennis, producing rackets, clubs, shoes, shuttlecocks, tennis balls, and other equipment for those sports. 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 two years an export company was created for the worldwide distribution. After the company began to make badminton racquets in 1969. The company began to experiment with graphite shafts for both types of rackets and found that these would also be useful for golf clubs, finding a growing market, the Yonex Corporation was established in Torrance, California in July 1983. In 1992 Yonex introduced the widebody badminton racket, the Isometric 500, the more square head gave it a much larger striking surface, which provides a larger sweet spot to hit the shuttle. It led other manufacturers to follow suit in square-head or isometric designs, the parent company was listed on the Tokyo Stock Exchange in 1994. Yonex describes itself as the leader in golf, tennis. Yonex has also been teaming up with OCBC since 2007 to host the annual U. S. Open Grand Prix Badminton Championships, Yonex has managed to become the dominant corporate player in badminton. Yonex sponsors the All England Open Badminton Championships and is a partner of the Badminton World Federation which organizes the World Championships, upwards of 80% of competitive players use their racquets, as it is the preferred choice amongst professionals. Yonex is significant in both the tennis and golf industry and is a sponsor of professional athletes in all three sports. In May 2016, Yonex was ultra vires to criticize the Taiwan national team players have violated the dress code, during the period of 2016 Rio Olympics, Yonex provided unfit shoes to non-contract badminton player Tzu-Ying Tai. This forced Tai to wear shoes made by her personal sponsor brand, Victor. And this event caused a controversy due to Chinese Taipei Badminton Association is going to punish Tai based on Yonexs pressing, after Tais incident outbreak, there are other five victim badminton players in the same situation and got punished
31.
Wilson Sporting Goods
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The Wilson Sporting Goods Company is an American sports equipment manufacturer based in Chicago, Illinois. Since 1989, it has been a subsidiary of the Finnish group Amer Sports. The company traces its roots to the Schwarzschild & Sulzberger meatpacking company based in New York, Sulzberger & Sons founded the Ashland Manufacturing Company in 1913 to use animal by-products from its slaughterhouses. It started out making tennis racket strings, violin strings, and surgical sutures but soon expanded into baseball shoes and tennis racquets. In 1915, Thomas E. Wilson, former president of meatpacker Morris & Company, was appointed President by the controlling banks, the company acquired the Hetzinger Knitting Mills to produce athletic uniforms and a caddie bag company which produced golf balls but soon expanded into footballs and basketballs. In 1918, Wilson left to concentrate on the beef-packing business, the packing company continued to have control in the company until 1966 when it was sold to LTV. Icely it acquired the Chicago Sporting Goods Company and struck a deal to supply the Chicago Cubs and it also hired Arch Turner, a leather designer who would design the leather football. In 1922, it introduced the Ray Schalk catchers mitt which became the standard and it worked with Knute Rockne to introduce the double-lined leather football and first valve football and the first waist-line football pants with pads. In 1925, it was renamed Wilson-Western Sporting Goods following an agreement with Western Sporting Goods. After Rocknes death, the focused on golf, introducing the R-90. In 1931, it renamed itself Wilson Sporting Goods Company, Horween Leather Company has supplied Wilson with pebbled cowhide since 1941 for use in the manufacture of footballs and basketballs. Wilson is Horween Leather Companys largest customer, after the war, Wilson focused on tennis and signed Jack Kramer, who developed its line of Jack Kramer signed tennis rackets. Icley died in 1950 but the continued to expand with many believing that Icelys introduction of a computer to monitor inventory had been a huge help. In 1955, it acquired Ohio-Kentucky Manufacturing for making footballs, in 1964 it acquired Wonder Products Company, which made toys and custom-molded items. It transformed the custom-mold section to make protective equipment in football and baseball, such as masks for football helmets. In 1967, the company was acquired by Ling-Temco-Vought, only three years after, PepsiCo became new Wilsons owner. In 1979, Wilson tennis balls were first used in the US Open, in 2006, the Australian Open began using Wilson Tennis Balls. In 1985, Wilson was acquired by Westray Capital Corporation through subsidiary WSGC Holdings, in 1989, WSGC merged with Bogey Acquisitions Company, which is affiliated with the Finnish group Amer Sports
32.
Dunlop Sport
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Dunlop Sport is a British sporting goods company that specialises in tennis and golf equipment. Dunlop have manufactured sporting equipment since 1910, in most parts of the world, Dunlop Sports is owned by Sports Direct International. The brand is owned by SRI Sports in Japan, Taiwan, Dunlop was established as a company manufacturing goods from rubber in 1889. The company entered the sporting market in 1910, when it began to manufacture rubber golf balls at its base in Birmingham. The company introduced the Maxfli golf ball in 1922, Dunlop extended into tennis ball manufacture in 1924. In 1925, F A Davis was acquired, which had tennis racket manufacturing expertise, Dunlop opened acquisition discussions with Slazenger in 1927, but without success. In 1928 the sports became a subsidiary of Dunlop Rubber named Dunlop Sports. Headquarters were relocated from Birmingham to Waltham Abbey in Essex, the Dunlop Masters golf tournament was established in 1946. It was sponsored by Dunlop until 1982, and is now known as the British Masters, in 1957 Dunlop acquired the golf club manufacturer John Letters of Scotland. In 1959 the Slazenger Group was acquired, the Dunlop flying D logo was introduced in 1960. In the 1970s and 1980s, Dunlop was slow to adapt to the new materials that tennis rackets were increasingly being made from, in 1983 the John Letters golf club business was sold back to members of the Letters family. In 1984 the sports businesses were merged to form Dunlop Slazenger, in 1986, the parent company, Dunlop Holdings, was acquired by the industrial company BTR for £549 million. BTR cut marketing spending to just 8 per cent of sales and reduced investment in grass roots sponsorship and research, steffi Grafs sponsorship money was cut so she defected to a Wilson racket. In 1996 Dunlop Slazenger was acquired by the equity firm Cinven for £330 million. To save money, Cinven moved production of Dunlop tennis balls from England to the Philippines, Slazenger Golf and Maxfli were sold off to reduce debt. Sports Direct International bought Dunlop Slazenger for £40 million in 2004, in December 2016, Sports Direct announced it had agreed to sell the Dunlop brand to Sumitomo Rubber Industries for £112 million. Sumitomo already own the rights to the brand in Japan, South Korea, the sale is due to be completed by May 2017. More tennis Grand Slams have been won with Dunlop rackets than any other brand, Dunlop Sport is the current supplier for the ATP World Team Championship in Düsseldorf
33.
Head (company)
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Head N. V. is a Dutch sports equipment and clothing company, which sells alpine skis and tennis rackets. Head Ski Company produced one of the first successful metal-wood composite downhill ski, the Head Standard, the company is headquartered in Amsterdam, Netherlands. Head worked at the Glenn L. Martin Company where they used a form of aluminum and plastic laminate to build the fuselages of aircraft, and he felt the same material would make an ideal ski. After two years of constantly breaking skis, by the winter of 1950 they had a design not only stayed together, but made turning dramatically easier. S. Head resisted the change to fibreglass construction and was known for interfering in day-to-day operations, in 1967, Howard Head hired Harold Seigle as company president, and became the Chairman of the Board and CEO. Bored of the results, in 1969 Head sold the company to AMF in 1969 and he later bought a controlling interest in Prince Sports. In the late 1960s, a division was created when Howard Head figured out a way of strengthening the tennis racket by introducing the aluminium frame. The idea became a success and was first introduced in the 1969 US Open, after Howard Heads departure, one of the tennis players that Head sponsored, Arthur Ashe, won Wimbledon, defeating favored Jimmy Connors in 1975. Also during the 1970s, Head acquired a manufacturer, Mares. While under AMF ownership, Head manufactured tennis racquets in Boulder, Colorado, also in 1969, Head signed Olympic champion ski racer Jean-Claude Killy to endorse a new metal and fiberglass ski, the Killy 800. Head subsequently developed a product line of Killy skis. In 1985, Minneapolis-based Minstar Inc. acquired Head through hostile takeover of AMF, two years later, Head started making athletic footwear, and introduced the Radial Tennis Shoes. The following year, Head opened a new plant in Austria in order to more tennis rackets. In 1989, management bought out Head, Tyrolia, and Mares, the takeover was backed by private equity firm Freeman Spogli & Co. In 1993, HTM was sold to tobacco conglomerate Austria Tabak, johan Eliasch, the current chairman, took over the company in 1995, which in 2014 was a Netherlands Antilles corporation. In 1997, Head created the first titanium and graphite tennis racket, over the next two years, Head acquired three more companies, DACOR, BLAX, and Penn Racquet Sports. Penn tennis balls are used in many tournaments worldwide, while Penn racquetballs are the official balls of the IRT. Penn once produced tennis balls and racquetballs in Phoenix, Arizona, in March 2009, Head shut down the Penn ball manufacturing factory
34.
Tecnifibre
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Tecnifibre is a French manufacturer of sporting equipment, specializing in tennis and squash. It was founded in 1979 by the current CEO Thierry Maissant, throughout its development, Tecnifibre has built itself a worldwide reputation in the tennis and squash market, releasing rackets, bags, strings, apparel and other accessories. Tecnifibre first became known for its expertise in strings, especially in multifilament, thanks to a unique technology, in 2004, Tecnifibre decided to launch its own range of rackets for competitors. Tecnifibre is also active in squash
35.
Steffi Graf
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Stefanie Maria Steffi Graf is a German former tennis player, who was ranked world No.1 during her career. Graf won 22 Grand Slam singles titles and her 22 singles titles puts her second on the list of Major wins by a tennis player since the introduction of the Open Era in 1968 and is third all-time behind Margaret Court and Serena Williams. In 1988, she became the first and only player to achieve the Golden Slam by winning all four Grand Slam singles titles. Furthermore, she is the tennis player to have won each Grand Slam event at least four times. She won 107 singles titles, which ranks her third on the WTAs all-time list after Martina Navratilova and she and Margaret Court are the only players, male or female, to win three grand slams in a calendar year five times. Notable features of Grafs game were her versatility across all playing surfaces, footwork, Graf won six French Open singles titles, seven Wimbledon singles titles, four Australian Open titles, and five U. S. Open singles titles. She is the singles player to have achieved a Grand Slam since hard court was introduced as a surface at the US Open in 1978. Consequently, Grafs Grand Slam was achieved on grass, clay, Graf reached thirteen consecutive Grand Slam singles finals, from the 1987 French Open through to the 1990 French Open, winning nine of them. She won 5 consecutive Majors, and seven Majors out of eight and she reached a total of 31 Grand Slam singles finals. Graf is regarded by some to be the greatest female player of all time. Navratilova included Graf on her list of great players, in 1999 Billie Jean King said Steffi is definitely the greatest womens tennis player of all time. In December 1999, Graf was named the greatest female player of the 20th century by a panel of experts assembled by the Associated Press. Tennis writer Steve Flink, in his book The Greatest Tennis Matches of the Twentieth Century, in March 2012, Tennis Channel picked Graf as the greatest female tennis player ever in their list of 100 greatest tennis players of all time. Graf retired in 1999 while she was ranked World No.3 and she married former World No.1 mens tennis player Andre Agassi in October 2001. The couple have two children – Jaden Gil and Jaz Elle, Graf was inducted into the Tennis Hall of Fame in 2004. Stefanie Graf was born on 14 June 1969, in Mannheim, Baden-Württemberg, West Germany, to Heidi Schalk and Peter Graf, when she was nine years old her family moved to the neighbouring town of Bruhl. She has a younger brother Michael, Graf was introduced to tennis by her father, an aspiring tennis coach, who taught his three-year-old daughter how to swing a wooden racket in the familys living room. She began practicing on a court at the age of four and she soon began winning junior tournaments with regularity, and in 1982 she won the European Championships 12s and 18s
36.
John McEnroe
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John Patrick McEnroe Jr. is an American former World No.1 professional tennis player, often rated among the greatest players of all time in the sport, especially for his touch on the volley. He won seven Grand Slam singles titles, nine Grand Slam mens doubles titles and he also won a record eight year-end championships,19 Grand Prix Super Series titles, and finished his career with 77 ATP-listed singles titles and 78 in doubles. In 1981,1983 and 1984 he was both the ATP player of the year and the ITF World Champion for Mens singles and his match record of 82–3 in 1984 remains the best single season win rate of the Open Era. McEnroe is a former Captain of the United States Davis Cup team and he continues to play tennis and competes in senior events on the ATP Champions Tour. He was inducted into the International Tennis Hall of Fame in 1999, after his tennis career he became a television commentator, a game show host and a chat show host. Additionally, he has appeared in films and television shows as himself and has played music live. He has been married since 1997 to musician and former Scandal lead singer Patty Smyth, McEnroe was born in Wiesbaden, Hessen, West Germany, to American parents, John Patrick McEnroe Sr. and his wife Kay, née Tresham. His father, who is of Irish descent, was at the time stationed with the United States Air Force, in 1960, the family moved to the New York City area, where McEnroes father worked daytime as an advertising agent while attending Fordham Law School by night. He has two brothers, Mark and former professional tennis player Patrick. McEnroe grew up in Douglaston, Queens, New York City and he started playing tennis when he was eight, at the nearby Douglaston Club with his brothers. When he was nine, his parents enrolled him in the Eastern Lawn Tennis Association and he then began competing in national juniors tournaments, and at twelve—when he was ranked seven in his age group—he joined the Port Washington Tennis Academy, Long Island, New York. McEnroe attended Trinity School and graduated in 1977 and it was the best performance by a qualifier at a Grand Slam tournament and a record performance by an amateur in the open era. After Wimbledon in 1977, McEnroe entered Stanford University and won the National Collegiate Athletic Association singles, later in 1978, he joined the ATP tour and signed his first professional endorsement deal, with Sergio Tacchini. He again advanced to the semifinals at a Grand Slam, this time the US Open, following which, he proceeded to win five titles that year, including his first Masters Grand Prix, beating Arthur Ashe in straight sets. In 1979, McEnroe won the Wimbledon Doubles title, the duo later adding the 1979 US Open Doubles title to their haul as well, McEnroe won his first Grand Slam singles title at the US Open. He defeated his friend Vitas Gerulaitis in straight sets in the final to become the youngest male winner of the title at the US Open since Pancho Gonzales. He also won the prestigious season-ending WCT Finals, beating Björn Borg in four sets, McEnroe won 10 singles and 17 doubles titles that year. At Wimbledon, McEnroe reached the 1980 Wimbledon Mens Singles final—his first final at Wimbledon—where he faced Björn Borg, at the start of the final, McEnroe was booed by the crowd as he entered Centre Court following heated exchanges with officials during his semifinal victory over Jimmy Connors
37.
Martina Navratilova
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Martina Navratilova is a Czech and American retired tennis player and coach. In 2005, Tennis magazine selected her as the greatest female player for the years 1965 through 2005. She won 18 Grand Slam singles titles,31 major womens doubles titles and she and Billie Jean King each won 20 Wimbledon titles, an all-time record. Navratilova is one of just three women ever to have accomplished a Career Grand Slam in singles, womens doubles, and mixed doubles, Navratilova holds the records for most singles titles and for most doubles titles in the open era. Her record as No.1 in singles is the most dominant in professional tennis, over five consecutive seasons, she won 428 of 442 singles matches, averaging fewer than 3 losses per year to 87 wins, for a sustained winning percentage of 96. 8%. She holds the best season record for the open era, 86-1 in 1983. She recorded the longest winning streak in the era and three of the six longest winning streaks. She and Serena Williams are the only Open Era players to have won six major singles crowns without the loss of a set, Navratilova, Margaret Court and Maureen Connolly share the record for the most consecutive major singles titles. Navratilova reached 11 consecutive major finals, second all-time to Steffi Grafs 13. Navratilova also won the season-ending WTA Tour Championships for top ranked players a record eight times and she is the only person of either sex to have won eight different tournaments at least seven times. Navratilova is regarded by some to be the greatest female player of all time. In womens doubles, Navratilova and Pam Shriver won 109 consecutive matches, the pair set an all-time record of 79 titles together and tied Louise Brough Clapps and Margaret Osborne duPonts record of 20 major womens doubles titles as a team. Navratilova also won the WTA Tour Championships doubles title a record 11 times and she is one of only five tennis players all-time to win a multiple slam set in two disciplines, matching Margaret Court, Roy Emerson, Frank Sedgman and Serena Williams. Navratilova took her last major title in 2006, winning the doubles crown at the 2006 US Open. Originally from Czechoslovakia, she was stripped of her citizenship when, in 1975 at the age of 18, at the time, Navratilova was told by the Czechoslovak Sports Federation that she was becoming too Americanized and that she should go back to school and make tennis secondary. Navratilova became a US citizen in 1981, and on January 9,2008 and she stated she has not renounced her U. S. citizenship nor does she plan to do so and that acquiring her Czech citizenship was not politically motivated. Navratilova was born Martina Šubertová in Prague, Czechoslovakia and her parents divorced when she was three, and her mother, an accomplished gymnast, tennis player, and ski instructor, moved the family to Řevnice. In 1962, her mother Jana married Miroslav Navrátil, who became her first tennis coach, Martina then took the name of her stepfather, thus becoming Martina Navrátilová
38.
John Isner
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John Robert Isner is an American professional tennis player. Considered one of the best servers of the ATP World Tour, in 2013, he became the 18th player to serve more than 5,000 aces on the ATP World Tour. He currently has 5th-most aces in the history of ATP, having served more than 8,700 aces. At the 2010 Wimbledon Championships, he played the longest professional match in history. He also played the then 10th-longest singles match, a 5-hour 41-minute encounter in the round of the 2012 French Open. Isner began his career in earnest in the summer of 2007. With a world ranking of no,839, he needed wildcard entries into the main draws of every tournament, even at the Futures level. He won his first tournament of the summer, the USA F14 Futures, at the following weeks tournament at the Legg Mason Tennis Classic in Washington, D. C. a late withdrawal freed up a wildcard spot, which was given to Isner at the last minute. Isner took full advantage of his fortune, recording his first wins over top-100 players. His week raised his ranking to no.193 in the world after six weeks on the pro tour, Isners Washington success earned him wildcard entries into three more ATP tournaments, the Masters Series event in Cincinnati a week later, New Haven, and the US Open. He lost in the first round in Cincinnati to quarterfinalist no.15 David Ferrer, the following week in New Haven, he beat no.49 Becker a second time, before falling to Ferrer for the second week in a row. In his US Open début, he defeated the 26th-seeded player, former quarterfinalist Jarkko Nieminen and he proceeded to win his second-round match against Rik de Voest, before losing in the third round to top seed and eventual champion Roger Federer. Isner was one of two players to take a set from Federer in the championship. His US Open performance improved his ranking to no.144, after the US Open, Isner continued to play exclusively in North America and finished the year ranked no.107. That year, Isner was added to the United States Davis Cup team as a practice partner, Isners no.106 ranking in November 2007 was just good enough to get him direct entry into his first Australian Open, after several players ranked above him dropped out. He was defeated in the first round of the 2008 Australian Open by veteran Fabrice Santoro of France, teamed with Croat Ivo Karlović, Isner also lost in the first round of doubles. Isner broke into the top 100 at no.93 in February with an appearance at the ATP event in San Jose, beating no.90 Florent Serra. He maintained a ranking in the first three months of the year, beating six players in the top 100, while playing exclusively in ATP-level events
39.
Marion Bartoli
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Marion Bartoli is a French former professional tennis player. She won the 2013 Wimbledon Championships singles title after previously being runner-up in 2007 and was a semifinalist at the 2011 French Open and she also won eight Womens Tennis Association singles titles and three doubles titles. She announced her retirement from professional tennis on 14 August 2013. Bartoli defeated three reigning world no and she was known for her unorthodox style of play using two hands on both her forehand and backhand. On 30 January 2012 she reached a high ranking of no.7 in the world. Bartoli reached at least the stage at each of the four Grand Slams. Her win at Wimbledon made her only the player in the open era to win the Championships without dropping a single set. She is also the player ever to have played at both the WTA Tour Championships and the WTA Tournament of Champions in the same year, in 2011. In July 2016 she revealed that she feared for her due to an unknown virus. However later in the month she tweeted a photo after a blood transfusion that indicated recovery was in sight, Marion Bartoli was born on 2 October 1984 in Le Puy-en-Velay, Haute-Loire. She is of Corsican descent, her family is from Palneca, Bartoli was introduced to tennis by her medical doctor father, Walter, when she was 6 years old. She would practice tennis with him late at night school on small, icy, unevenly surfaced courts which restricted free movement. He drove hundreds of kilometres to tournaments while she would do her homework in the back of the car, Bartoli was known for her unorthodox and intense style of play on the court. She used two hands on both the forehand and the backhand, and was classed as an aggressive and hard-hitting player who played primarily from the baseline. She developed her style on the advice of her father and longtime coach. He had seen the classic 1992 French Open final in which Monica Seles defeated Steffi Graf, Bartoli had previously had trouble with her forehand, but it improved significantly when she made the switch to two hands. Her game was based on power and she used her double-fisted strokes to create sharp angles to open up the court, Bartoli was not a natural athlete so she was not a strong mover around the court and instead relied on her excellent hand-eye coordination and anticipation skills. Her style of play could be most closely compared to that of Seles, who had a strong influence on Bartoli as a young player
40.
Pete Sampras
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Petros Pete Sampras is an American retired tennis player. He was a longtime world No.1 and is regarded one of the greatest players in tennis history and he was particularly esteemed for his precise serve, earning the nickname Pistol Pete. His career began in 1988 and ended at the 2002 US Open, Sampras became the first professional to break Roy Emersons pre-Open Era record of 12 Grand Slam singles titles. He retired with 14 titles, a record surpassed by Roger Federer in 2009, Sampras other achievements include a record six ATP Player of the Year awards due to his ATP record six year-end No.1 rankings from 1993 through 1998. He also won seven year-end championships, Sampras was born in Washington, D. C. the third child of Soterios Sammy and Georgia Sampras. His mother emigrated from Sparta, Greece, and his father was born in the United States to a Greek father, Costas Gus Sampras and he attended regular services of the Greek Orthodox Church on Sundays. From an early age, Sampras showed signs of outstanding athletic ability, at the age of 3, Sampras discovered a tennis racket in the basement of his home and spent hours hitting balls against the wall. In 1978, the Sampras family moved to Palos Verdes, California, from early on, his great idol was Rod Laver, and at the age of 11, Sampras met and played with him. The Sampras family joined the Jack Kramer Club, and it was here that Samprass talent became apparent and he was spotted by Peter Fischer, a pediatrician and tennis enthusiast, who coached Sampras until 1989. Fischer was responsible for converting Samprass double-handed backhand to single-handed with the goal of being prepared to win Wimbledon. Sampras turned professional in 1988, at the age of 16 and his first professional match was a loss to Sammy Giammalva, Jr. at the February Ebel U. S. However, just one week later at the Lipton International Players Championships in Miami and he did not defeat another top-40 player for almost six months, when he defeated World No.39 Michiel Schapers at a US Open warm-up tournament in Rye Brook, New York. In his first Grand Slam singles match, Sampras lost to World No.69 Jaime Yzaga of Peru in the first round of the US Open. Sampras did not advance past the quarterfinals in his three tournaments, although he did record wins over World No.79 Jim Courier in their first career match-up. The following year, Sampras slightly improved his ranking to a world number 81. He lost in the first round of the 1989 Australian Open to Christian Saceanu and he won a Grand Slam singles match for the first time at the French Open, before losing in the second round to eventual champion, 17-year-old Michael Chang, in their first career match-up. At the US Open, Sampras defeated defending champion and fifth-seeded Mats Wilander in the round before losing to World No.13 Jay Berger in the fourth round. To end the year, Sampras lost in the first round of four consecutive tournaments, Sampras finished 1990 at World No
41.
Lead
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Lead is a chemical element with atomic number 82 and symbol Pb. When freshly cut, it is bluish-white, it tarnishes to a dull gray upon exposure to air and it is a soft, malleable, and heavy metal with a density exceeding that of most common materials. Lead has the second-highest atomic number of the stable elements. Lead is a relatively unreactive post-transition metal and its weak metallic character is illustrated by its amphoteric nature and tendency to form covalent bonds. Compounds of lead are found in the +2 oxidation state. Exceptions are mostly limited to organolead compounds, like the lighter members of the group, lead exhibits a tendency to bond to itself, it can form chains, rings, and polyhedral structures. Lead is easily extracted from its ores and was known to people in Western Asia. A principal ore of lead, galena, often bears silver, Lead production declined after the fall of Rome and did not reach comparable levels again until the Industrial Revolution. Nowadays, global production of lead is about ten million tonnes annually, Lead has several properties that make it useful, high density, low melting point, ductility, and relative inertness to oxidation. In the late 19th century, lead was recognized as poisonous, Lead is a neurotoxin that accumulates in soft tissues and bones, damaging the nervous system and causing brain disorders and, in mammals, blood disorders. A lead atom has 82 electrons, arranged in a configuration of 4f145d106s26p2. The combined first and second ionization energies—the total energy required to remove the two 6p electrons—is close to that of tin, leads upper neighbor in group 14. This is unusual since ionization energies generally fall going down a group as an elements outer electrons become more distant from the nucleus, the similarity is caused by the lanthanide contraction—the decrease in element radii from lanthanum to lutetium, and the relatively small radii of the elements after hafnium. The contraction is due to shielding of the nucleus by the lanthanide 4f electrons. The combined first four ionization energies of lead exceed those of tin, for this reason lead, unlike tin, mostly forms compounds in which it has an oxidation state of +2, rather than +4. Relativistic effects, which become particularly prominent at the bottom of the periodic table, as a result, the 6s electrons of lead become reluctant to participate in bonding, a phenomenon called the inert pair effect. A related outcome is that the distance between nearest atoms in crystalline lead is unusually long, the lighter group 14 elements form stable or metastable allotropes having the tetrahedrally coordinated and covalently bonded diamond cubic structure. The energy levels of their outer s- and p-orbitals are close enough to allow mixing into four hybrid sp3 orbitals
42.
Venus Williams
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Ranked World No.11 in singles as of January 28,2017, Williams has been ranked World No.1 by the Womens Tennis Association on three occasions, for a total of 11 weeks. She first became the World No.1 on February 25,2002, on 10 June 2002, Venus and Serena became the first sisters to hold the No.1 and No.2 spots in the singles rankings, respectively. On 7 June 2010, Venus became co-No,1 in doubles with Serena after they won their 4th consecutive grand slam doubles title at Roland Garros. By virtue of that doubles ascension, Venus became one of seven women to reach No.1 in singles. On 21 June 2010, Venus and Serena again occupied the No.2 and No.1 spots in the singles rankings, astonishingly, this came almost exactly 8 years after first accomplishing this feat. At the time, Venus had just celebrated her 30th birthday and her seven Grand Slam singles titles ties her twelfth on the all-time list, more than any other active female player except sister Serena. She has also won fourteen Grand Slam doubles titles and two mixed doubles titles and her five Wimbledon singles titles ties her with two other women for eighth place on the all-time list. Williams is one of four women to have won five or more Wimbledon singles titles in the Open Era, from the 2000 Wimbledon Championships to the 2001 US Open, Williams won four of the six Grand Slam singles tournaments held. She is one of six women in the Open Era to win 200 or more main draw Grand Slam singles matches. As of the 2017 Australian Open, Williams extends her record as the leader, male or female, in Grand Slams played. Williams has won four Olympic gold medals, one in singles and she and Serena have won more Olympic gold medals than any other tennis player, male or female. Venus also holds the record for the most Olympic medals won by a male or female tennis player and she is the only tennis player to have won a medal at four separate Olympic Games. At the 2000 Sydney Olympics, Williams became only the player to win Olympic gold medals in both singles and doubles at the same Olympic Games, after Helen Wills Moody in 1924. With 49 singles titles, Williams is behind only Serena among active players on the WTA Tour and her 35-match winning streak from the 2000 Wimbledon Championships to the 2000 Generali Ladies Linz tournament final is the longest since January 1,2000. She is also one of three active WTA players to have made the finals of all four Grand Slams, along with Serena. By winning her 49th career singles title at the 2016 Taiwan Open, Williams became the 5th oldest WTA Tour titlist in the Open Era, Williams has played against her sister in 27 professional matches since 1998, and won 11. They have played against each other in nine Grand Slam singles finals, Venus has 8 runner-up finishes in grand slam singles events with Martina Hingis being the only player other than Serena to beat Venus in a major final at the 1997 US Open. Beginning with the 2002 French Open, they opposed each other in four consecutive Grand Slam singles finals, on the other side, the pair have won 14 Grand Slam doubles titles playing alongside each other and are undefeated in Grand Slam finals
43.
Andy Roddick
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Andrew Stephen Andy Roddick is an American former professional tennis player. He became a Grand Slam singles champion, and world number one, despite several more years as one of the worlds best players that would remain his only Grand Slam triumph. He is the most recent North American male player to win a Grand Slam singles event, the most recent to reach the top ranking, and the most recent to claim the year-end world No.1. Roddick reached four other Grand Slam finals, losing to Roger Federer every time, Roddick was ranked in the top 10 for 9 consecutive years between 2002 and 2010, at years end, and won five Masters Series in that period. He is married to Brooklyn Decker, a former Sports Illustrated swimwear model, on August 30,2012, during the 2012 US Open and on his 30th birthday, Roddick announced that he would retire after the tournament. Following a fourth-round defeat by Juan Martín del Potro, Roddick retired from the sport with the aim of focusing on his foundation, in 2015, Roddick played for the Austin Aces in World Team Tennis. This was his eighth season in World Team Tennis and the team he has played for. Roddick was born in Omaha, Nebraska, the son of Blanche, a teacher, and Jerry Roddick. Roddick has two brothers, Lawrence and John, who were both promising tennis players at a young age. Roddick played varsity basketball in school alongside his future Davis Cup teammate Mardy Fish. During that time period, he trained with Venus and Serena Williams. His tennis idol growing up was Andre Agassi, Roddick considered quitting competitive tennis at the age of 17, when he had a losing streak in the juniors. His coach, Tarik Benhabiles, talked him into giving tennis four more months of undivided attention, Roddick finished as the No.6 junior in the U. S. in 1999, and as the No.1 junior in the world in 2000. He won six world junior titles and seven world junior doubles titles. In March in Miami, in the first round Roddick had his first ATP level victory as he beat World No.41 Fernando Vicente of Spain, 6–4, 6–0. In August in Washington, D. C. he beat World No.30 Fabrice Santoro of France, 4–6, Roddick played the Banana Bowl in the city of São Paulo and won, beating Joachim Johansson in the final. Roddick also won the Australian Junior Open, defeating Mario Ančić in the final, in 2001, Roddick defeated former French Open champion Michael Chang in five sets in the second round of the tournament, despite the fact that clay was Roddicks worst surface. During the following Wimbledon, he showed potential by taking a set from eventual winner Goran Ivanišević
