|
Shock Cord
file:Bungee Cord PICT6882a.jpg, Bungee cords equipped with metal hooks A bungee cord (sometimes spelled bungle; also known as a shock cord) is an elastomer, elastic cord composed of one or more elastic strands forming a core, usually covered in a woven cotton or polypropylene sheath. The sheath does not materially extend elastically, but it is braided with its strands spiralling around the core so that a longitudinal pull causes it to squeeze the core, transmitting the core's elastic compression to the longitudinal extension of the sheath and cord. Specialized bungees, such as some used in bungee jumping, may be made entirely of elastic strands. Uses file:Moscow Russia Park Kid on Bungee_Cord.jpg, upA child on a bungee cord device in Moscow, Russia Bungee cords have been used to provide a lightweight suspension for aircraft undercarriages from before World War I, and are still used on many small homebuilt aircraft where weight remains critical. Bungee cords were also used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bungee Cord PICT6882a
Bungee may refer to: * Bungee cord, also called shock cord, an engineered stretchable cord ** Bungee chair, a type of office or lounge chair made with bungee cords * Bungee jumping, an adventure sport * Bungee language or Bungi creole, a language and its related population, which exist mainly along the north–south trade routes of Manitoba, Canada See also * Bungie, an independent video game developer {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomer
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypropylene
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins and is partially crystalline and non-polar. Its properties are similar to polyethylene, but it is slightly harder and more heat-resistant. It is a white, mechanically rugged material and has a high chemical resistance. Bio-PP is the bio-based counterpart of polypropylene (PP). Polypropylene is the second-most widely produced commodity plastic (after polyethylene). In 2019, the global market for polypropylene was worth $126.03 billion. Revenues are expected to exceed US$145 billion by 2019. The sales of this material are forecast to grow at a rate of 5.8% per year until 2021. History Phillips Petroleum chemists J. Paul Hogan and Robert Banks first demonstrated the polymerization of propylene in 1951. The stereoselective polymerization t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bungee Jumping
Bungee jumping (), also spelled bungy jumping, is an activity that involves a person jumping from a great height while connected to a large elastic cord. The launching pad is usually erected on a tall structure such as a building or crane, a bridge across a deep ravine, or on a natural geographic feature such as a cliff. It is also possible to jump from a type of aircraft that has the ability to hover above the ground, such as a hot-air-balloon or helicopter. The thrill comes from the free-falling and the rebound. When the person jumps, the cord stretches and the jumper flies upwards again as the cord recoils, and continues to oscillate up and down until all the kinetic energy is dissipated. Early tethered jumping The land diving ( Sa: ') of Pentecost Island in Vanuatu is an ancient ritual in which young men jump from tall wooden platforms with vines tied to their ankles as a test of their courage and passage into manhood. Unlike in modern bungee-jumping, land-divers in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moscow Russia Park Kid On Bungee Cord
Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million residents within the city limits, over 17 million residents in the urban area, and over 21.5 million residents in the metropolitan area. The city covers an area of , while the urban area covers , and the metropolitan area covers over . Moscow is among the world's largest cities; being the most populous city entirely in Europe, the largest urban and metropolitan area in Europe, and the largest city by land area on the European continent. First documented in 1147, Moscow grew to become a prosperous and powerful city that served as the capital of the Grand Duchy that bears its name. When the Grand Duchy of Moscow evolved into the Tsardom of Russia, Moscow remained the political and economic center for most of the Tsardom's history. When the Ts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Institute Of Aeronautics And Astronautics
The American Institute of Aeronautics and Astronautics (AIAA) is a professional society for the field of aerospace engineering. The AIAA is the U.S. representative on the International Astronautical Federation and the International Council of the Aeronautical Sciences. In 2015, it had more than 30,000 members among aerospace professionals worldwide (a majority are American and/or live in the United States). History The AIAA was founded in 1963 from the merger of two earlier societies: the American Rocket Society (ARS), founded in 1930 as the American Interplanetary Society (AIS), and the Institute of the Aerospace Sciences (IAS), founded in 1932 as the Institute of the Aeronautical Sciences. Paul Johnston was the first executive director of the organization. Jim Harford took his seat after 18 months. The newly-formed structure gathered 47 technical committees and one broad technical publication, the ''AIAA Journal''. The ''AIAA Student Journal'' was also launched in 1963. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parachuting
Parachuting, including also skydiving, is a method of transiting from a high point in the atmosphere to the surface of Earth with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes. For human skydiving, it may involve a phase of more or less free-falling (the skydiving segment) which is a period when the parachute has not yet been deployed and the body gradually accelerates to terminal velocity. For cargo parachuting, the parachute descent may begin immediately, such as a parachute-airdrop in the lower atmosphere of Earth, or be significantly delayed, such as in a planetary atmosphere where an object is descending "under parachute" following atmospheric entry from space, and may begin only after the hypersonic entry phase and initial deceleration that occurs due to friction with the thin upper atmosphere. History Common uses Parachuting is performed as a recreational activity and a competitive sport, and is widel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ripcord (skydiving)
A ripcord is a part of a skydiving harness-container system; a handle attached to a steel cable ending in a closing pin. The pin keeps the container closed and keeps the spring-loaded pilot chute inside. When the ripcord is pulled, the container is opened and the pilot chute is released, opening the parachute. On tandem systems the ripcord releases the 3-ring release system anchoring the bridle to the harness-container, allowing the parachute to open. The ripcord was invented in 1914 by Tiny Broadwick. See also * Pullstring A pullstring (pull string, pull-string), pullcord (pull cord, pull-cord), or pullchain (pull-chain, pull chain) is a twine, string, rope, cord, or chain wound on a Spring (device), spring-loaded spindle (tool), spindle that engages a mechanism ( ... References Parachuting {{Air-sports-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot
A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ''bend'' fastens two ends of a rope to each another; a ''loop knot'' is any knot creating a loop; and ''splice'' denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory. History Knots and knotting have been used and studied throughout history. For example, Chinese knotting is a decorative handicraft art that began as a form of Chinese folk art in the Tang and Song Dynasty (960–1279 AD) in China, later popularized in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Absorber
A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most shock absorbers are a form of dashpot (a damper which resists motion via viscous friction). Description Pneumatic and hydraulic shock absorbers are used in conjunction with cushions and springs. An automobile shock absorber contains spring-loaded check valves and orifices to control the flow of oil through an internal piston (see below). One design consideration, when designing or choosing a shock absorber, is where that energy will go. In most shock absorbers, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid heats up, while in air cylinders, the hot air is usually exhausted to the atmosphere. In other types of shock absorbers, such as electromagnetic types, the dissipated energy can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pickup Truck
A pickup truck or pickup is a light-duty truck that has an enclosed cabin, and a back end made up of a cargo bed that is enclosed by three low walls with no roof (this cargo bed back end sometimes consists of a tailgate and removable covering). In Australia and New Zealand, both pickups and coupé utilities are called utes, short for utility vehicle. In South Africa, people of all language groups use the term ''bakkie'', a diminutive of ''bak'', Afrikaans for "basket". Once a work or farming tool with few creature comforts, in the 1950s U.S. consumers began purchasing pickups for lifestyle reasons, and by the 1990s, less than 15% of owners reported use in work as the pickup truck's primary purpose. In North America, the pickup is mostly used as a passenger car and accounts for about 18% of total vehicles sold in the United States. Full-sized pickups and SUVs are an important source of revenue for major car manufacturers such as GM, Ford, and Stellantis, accounting for more th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
