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Tennis Ball
A tennis ball is a ball designed for the sport of tennis. Tennis balls are fluorescent yellow in organised competitions, but in recreational play can be virtually any color. Tennis balls are covered in a fibrous felt which modifies their aerodynamic properties, and each has a white curvilinear oval covering it. Specifications Modern tennis balls must conform to certain criteria for size, weight, deformation, and bounce criteria to be approved for regulation play. The International Tennis Federation (ITF) defines the official diameter as . Balls must have masses in the range . Yellow and white are the only colors approved by the ITF, and most balls produced are a fluorescent yellow known as "optic yellow", first introduced in 1972 following research demonstrating they were more visible on television. Tennis balls are filled with air and are surfaced by a uniform felt-covered rubber compound. The felt delays flow separation in the boundary layer which reduces aerodynamic drag an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennis Ball
A tennis ball is a ball designed for the sport of tennis. Tennis balls are fluorescent yellow in organised competitions, but in recreational play can be virtually any color. Tennis balls are covered in a fibrous felt which modifies their aerodynamic properties, and each has a white curvilinear oval covering it. Specifications Modern tennis balls must conform to certain criteria for size, weight, deformation, and bounce criteria to be approved for regulation play. The International Tennis Federation (ITF) defines the official diameter as . Balls must have masses in the range . Yellow and white are the only colors approved by the ITF, and most balls produced are a fluorescent yellow known as "optic yellow", first introduced in 1972 following research demonstrating they were more visible on television. Tennis balls are filled with air and are surfaced by a uniform felt-covered rubber compound. The felt delays flow separation in the boundary layer which reduces aerodynamic drag an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennis Balls, Advertisement, 19th Century
Tennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The object of the game is to manoeuvre 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 validly will not gain a point, while the opposite player will. Tennis is an Olympic sport and is played at all levels of society and at all ages. 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. It had close connections both to various field (lawn) games such as croquet and bowls as well as to the older racket sport today called real tennis. The rules of modern tennis have changed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammer-beam Roof
A hammerbeam roof is a decorative, open timber roof truss typical of English Gothic architecture and has been called "...the most spectacular endeavour of the English Medieval carpenter". They are traditionally timber framed, using short beams projecting from the wall on which the rafters land, essentially a tie beam which has the middle cut out. These short beams are called hammer-beams and give this truss its name. A hammerbeam roof can have a single, double or false hammerbeam truss. Design A hammer-beam is a form of timber roof truss, allowing a hammerbeam roof to span greater than the length of any individual piece of timber. In place of a normal tie beam spanning the entire width of the roof, short beams – the hammer beams – are supported by curved braces from the wall, and hammer posts or arch-braces are built on top to support the rafters and typically a collar beam. The hammerbeam truss exerts considerable thrust on the walls or posts that support it. Hamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine. Construction Rope may be constructed of any long, stringy, fibrous material, but generally is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are significantly stronger than their natural fibre counterparts, they have a higher tensile strength, they are more resistant to rotting than ropes created from natural fibres, and they can be made to float on water. But synthetic ropes also possess certain disadvantages, including slipperiness, and some can be damaged more easily by UV light. Common natural fibres for rope are Manila hemp, hemp, linen, cotton, coir, jute, straw, and sisal. Synthetic fibres in use for rope-making include polypropylene, nylon, polyeste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goat
The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the animal family Bovidae and the tribe Caprini, meaning it is closely related to the sheep. There are over 300 distinct breeds of goat.Hirst, K. Kris"The History of the Domestication of Goats".''About.com''. Accessed August 18, 2008. It is one of the oldest domesticated species of animal, according to archaeological evidence that its earliest domestication occurred in Iran at 10,000 calibrated calendar years ago. Goats have been used for milk, meat, fur, and skins across much of the world. Milk from goats is often turned into goat cheese. Female goats are referred to as ''does'' or ''nannies'', intact males are called ''bucks'' or ''billies'', and juvenile goats of both sexes are called ''kids''. Castrated males are called ''wethers''. Whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticated sheep. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Numbering a little over one billion, domestic sheep are also the most numerous species of sheep. An adult female is referred to as a ''ewe'' (), an intact male as a ''ram'', occasionally a ''tup'', a castrated male as a ''wether'', and a young sheep as a ''lamb''. Sheep are most likely descended from the wild mouflon of Europe and Asia, with Iran being a geographic envelope of the domestication center. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleeces, meat (lamb, hogget or mutton) and milk. A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following chewing. It performs a chemical breakdown by means of enzymes and hydrochloric acid. In humans and many other animals, the stomach is located between the oesophagus and the small intestine. The stomach secretes digestive enzymes and gastric acid to aid in food digestion. The pyloric sphincter controls the passage of partially digested food (chyme) from the stomach into the duodenum, where peristalsis takes over to move this through the rest of intestines. Structure In the human digestive system, the stomach lies between the oesophagus and the duodenum (the first part of the small intestine). It is in the left upper quadrant of the abdominal cavity. The top of the stomach lies ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artisan
An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art, sculpture, clothing, food items, household items and tools and mechanisms such as the handmade clockwork movement of a watchmaker. Artisans practice a craft and may through experience and aptitude reach the expressive levels of an artist. History The adjective "artisanal" is often used in describing hand-processing in contrast to an industrial process, such as in the phrase ''artisanal mining''. Thus, "artisanal" is sometimes used in marketing and advertising as a buzz word to describe or imply some relation with the crafting of handmade food products, such as bread, beverages or cheese. Many of these have traditionally been handmade, rural or pastoral goods but are also now commonly made on a larger scale with automated mec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scottish People
The Scots ( sco, Scots Fowk; gd, Albannaich) are an ethnic group and nation native to Scotland. Historically, they emerged in the early Middle Ages from an amalgamation of two Celtic-speaking peoples, the Picts and Gaels, who founded the Kingdom of Scotland (or ''Alba'') in the 9th century. In the following two centuries, the Celtic-speaking Cumbrians of Strathclyde and the Germanic-speaking Angles of north Northumbria became part of Scotland. In the High Middle Ages, during the 12th-century Davidian Revolution, small numbers of Norman nobles migrated to the Lowlands. In the 13th century, the Norse-Gaels of the Western Isles became part of Scotland, followed by the Norse of the Northern Isles in the 15th century. In modern usage, "Scottish people" or "Scots" refers to anyone whose linguistic, cultural, family ancestral or genetic origins are from Scotland. The Latin word '' Scoti'' originally referred to the Gaels, but came to describe all inhabitants of Scotl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis XI Of France
Louis XI (3 July 1423 – 30 August 1483), called "Louis the Prudent" (french: le Prudent), was King of France from 1461 to 1483. He succeeded his father, Charles VII. Louis entered into open rebellion against his father in a short-lived revolt known as the Praguerie in 1440. The king forgave his rebellious vassals, including Louis, to whom he entrusted the management of the Dauphiné, then a province in southeastern France. Louis's ceaseless intrigues, however, led his father to banish him from court. From the Dauphiné, Louis led his own political establishment and married Charlotte of Savoy, daughter of Louis, Duke of Savoy, against the will of his father. Charles VII sent an army to compel his son to his will, but Louis fled to Burgundy, where he was hosted by Philip the Good, the Duke of Burgundy, Charles' greatest enemy. When Charles VII died in 1461, Louis left the Burgundian court to take possession of his kingdom. His taste for intrigue and his intense diplomatic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osprey Publishing
Osprey Publishing is a British, Oxford-based, publishing company specializing in military history. Predominantly an illustrated publisher, many of their books contain full-colour artwork plates, maps and photographs, and the company produces over a dozen ongoing series, each focusing on a specific aspect of the history of warfare. Osprey has published over 2,300 books. They are best known for their ''Men-at-Arms'' series, running to over 500 titles, with each book dedicated to a specific historical army or military unit. Osprey is an imprint of Bloomsbury Publishing. History In the 1960s, the Brooke Bond Tea Company began including a series of military aircraft cards with packages of their tea. The cards proved popular, and the artist Dick Ward proposed the idea of publishing illustrated books about military aircraft. The idea was approved and a small subsidiary company called Osprey was formed in 1968. The company’s first book, ''North American P-51D Mustang in USAAF-USAF Ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Acts Of The Parliament Of England To 1483
This is a list of Acts of the Parliament of England for the years up until 1483. For Acts passed during the period 1707–1800 see List of Acts of the Parliament of Great Britain. See also the List of Acts of the Parliament of Scotland, the List of Acts of the Parliament of Ireland to 1700, and the List of Acts of the Parliament of Ireland, 1701–1800. For Acts passed from 1801 onwards see List of Acts of the Parliament of the United Kingdom. For Acts of the devolved parliaments and assemblies in the United Kingdom, see the List of Acts of the Scottish Parliament, the List of Acts of the Northern Ireland Assembly, and the List of Acts and Measures of the National Assembly for Wales; see also the List of Acts of the Parliament of Northern Ireland. For medieval statutes, etc. that are not considered to be Acts of Parliament, see the List of English statutes. The number shown after each Act's title is its chapter number. Acts are cited using this number, preceded by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
