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Spin (geometry)
Spin or spinning most often refers to: * Spin (physics) or particle spin, a fundamental property of elementary particles * Spin quantum number, a number which defines the value of a particle's spin * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin (geometry), the rotation of an object around an internal axis * Spin (propaganda), an intentionally biased portrayal of something Spin, spinning or spinnin may also refer to: Physics and mathematics * Spin group, Spin(''n''), a particular double cover of the special orthogonal group SO(''n'') ** the corresponding spin algebra, \mathfrak(n) * Spin tensor, a tensor quantity for describing spinning motion in special relativity and general relativity * Spin (aerodynamics), autorotation of an aerodynamically stalled aeroplane * SPIN bibliographic database, an indexing and abstracting service focusing on physics research Textile arts * Spinning (polymers), a process for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin (physics)
Spin is an Intrinsic and extrinsic properties, intrinsic form of angular momentum carried by elementary particles, and thus by List of particles#Composite particles, composite particles such as hadrons, atomic nucleus, atomic nuclei, and atoms. Spin is quantized, and accurate models for the interaction with spin require relativistic quantum mechanics or quantum field theory. The existence of electron spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible discrete angular momenta despite having no orbital angular momentum. The relativistic spin–statistics theorem connects electron spin quantization to the Pauli exclusion principle: observations of exclusion imply half-integer spin, and observations of half-integer spin imply exclusion. Spin is described mathematically as a vector for some particles such as photons, and as a spinor or bispinor for other particles such as electrons. Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indoor Cycling
Indoor cycling, often called spinning, is a form of exercise with classes focusing on endurance, strength, intervals, high intensity (race days) and recovery, and involves using a special stationary exercise bicycle with a weighted flywheel in a classroom setting. When people took cycling indoors in the late 19th century, whether for reasons of weather or convenience, technology created faster, more compact and efficient machines over time. The first iterations of the stationary bike ranged from the vertical Gymnasticon to regular bicycles on rollers. Class content and goals Classes generally use specialized exercise bicycle, stationary bicycles. Features include a mechanical device to modify the difficulty of pedaling, specially shaped handlebars, and multiple adjustment points to fit the bicycle to a range of riders. Many have a weighted flywheel, which simulates the effects of inertia and momentum when riding a real bicycle. The pedals are equipped with toe clips as on sports ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerard Holzmann
Gerard J. Holzmann (born 1951) is a Dutch-American computer scientist and researcher at Bell Labs and NASA, best known as the developer of the SPIN model checker. Early life and education Holzmann was born in Amsterdam, Netherlands and received an Engineer's degree in electrical engineering from the Delft University of Technology in 1976. He subsequently also received his PhD degree from Delft University in 1979 under Willem van der Poel and J.L. de Kroes with a thesis entitled ''Coordination problems in multiprocessing systems''. After receiving a Fulbright Scholarship he was a post-graduate student at the University of Southern California for another year, where he worked with Per Brinch Hansen. Career In 1980 he started at Bell Labs in Murray Hill for a year. Back in the Netherlands he was assistant professor at the Delft University of Technology for two years.Holzmann, Gerard J. "The Pandora System: an interactive system for the design of data communication protocols." '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPIN Model Checker
SPIN is a general tool for verifying the correctness of concurrent software models in a rigorous and mostly automated fashion. It was written by Gerard J. Holzmann and others in the original Unix group of the Computing Sciences Research Center at Bell Labs, beginning in 1980. The software has been available freely since 1991, and continues to evolve to keep pace with new developments in the field. Tool Systems to be verified are described in Promela (Process Meta Language), which supports modeling of asynchronous distributed algorithms as non-deterministic automata (''SPIN'' stands for "Simple Promela Interpreter"). Properties to be verified are expressed as Linear Temporal Logic (LTL) formulas, which are negated and then converted into Büchi automata as part of the model-checking algorithm. In addition to model-checking, SPIN can also operate as a simulator, following one possible execution path through the system and presenting the resulting execution trace to the user. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fokker Spin
The Fokker ''Spin'' was the first airplane built by Dutch aviation pioneer Anthony Fokker. The many bracing wires used to strengthen the aircraft made it resemble a giant spider, hence its name ''Spin'', Dutch for "spider". History Fokker built the ''Spin'' in 1910 in aviation, 1910 while he was a student in German Empire, Germany, assisted by Jacob Goedecker and a business partner, Franz von Daum, who procured the engine. The aircraft started out as an experimental design to provide Fokker with a means to explore his interest in flying. The first ''Spin'' was destroyed when Von Daum flew it into a tree, but the engine was still salvageable and was used to build the second version. This was built soon afterwards and was used by Fokker to teach himself to fly and to obtain his pilot license. This aircraft was also irreparably damaged by Von Daum. In Fokker's third model, he gained fame in his home country of the Netherlands by flying around the tower of the Grote Kerk, Haarlem, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chevrolet Spin
The Chevrolet Spin is a mini MPV produced by General Motors under the Chevrolet marque. Developed by General Motors do Brasil, GM do Brasil, the vehicle replaced the Chevrolet Meriva, Meriva and Chevrolet Zafira, Zafira in South America with an option of two-row and three-row seating. It is produced in Brazil since 2012 and has been exported throughout the South American region. Between 2013 and 2015, GM Indonesia assembled the vehicle for the Southeast Asian market at its Bekasi plant. Overview The Spin was mainly designed and engineered in Brazil by GM Brasil Centro Tecnológico São Caetano do Sul. During development, it was known as the PM5/PM7 project. The vehicle is developed to replace both the Chevrolet Meriva and Chevrolet Zafira in South America which was developed by Opel. It is built on the same platform as the Brazilian Chevrolet Cobalt#Second generation (2011), Chevrolet Cobalt. Developed with a goal of a large cabin space, the vehicle is built on a -long wheelba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Spinning
Metal spinning, also known as spin forming or spinning or metal turning most commonly, is a metalworking process by which a disc or tube of metal is rotated at high speed and formed into an axially symmetric part. Spinning can be performed by hand or by a CNC lathe. The metal spinning trade is one that dates back to antiquity and was a skill used in the Ancient Egyptian era. This is when metal spinning was limited to soft metals spun by human power on primitive lathes. The technique gave significant advances to hydro and steam power in Europe and North America in the 19th century and by the early 20th century the electric motor provided the necessary power and high-speed turning capability. With this advancement, metal spinning craftsmen were now able to spin higher quality pieces made out of brass, copper, aluminum and even stainless and cold-rolled steel. Metal spinning does not involve removal of material, as in conventional wood or metal turning, but forming (moulding) of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ten-pin Bowling
Tenpin bowling is a type of bowling in which a bowler bowling form, rolls a bowling ball down a wood or synthetic lane toward ten pins positioned Tetractys, evenly in four rows in an equilateral triangle. The goal is to knock down all ten Bowling pin, pins on the first roll of the ball (a strike), or failing that, on the second roll (a spare). While most people approach modern tenpin bowling as a simple recreational pastime, those who bowl competitively, especially at the highest levels, consider it a demanding sport requiring precision and skill. An approximately long ''approach'' area used by the bowler to impart speed and apply rotation to the ball ends in a ''foul line''. The , lane is bordered along its length by ''gutters'' (''channels'') that collect errant balls. The lane's long and narrow shape limits straight-line ball paths to angles that are smaller than optimum angles for achieving strikes; accordingly, bowlers impart side rotation to ''hook (bowling), hook'' (curv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pen Spinning
Pen spinning is a form of object manipulation that involves the Dexterity, deft manipulation of a writing instrument with hands. Although it is often considered a form of self-entertainment (usually in a school or office setting), multinational competitions and meetings are sometimes held. It is sometimes classified as a form of contact juggling; however, some tricks, e.g. "spreads" and "aerial tricks" do leave contact with the body. In addition to writing instruments, it is often also seen performed by drummers with their drumsticks. Pen spinning has quickly gained international popularity through online video sharing and forums. The hobby has been popular around the world since at least the 1970s. History The earliest record of pen spinning comes from a student in pre-World War II, WWII Japan. Others in Japan spun pens at least as early as the 1970s; however, the tricks performed were only basic ones, such as the ThumbAround and Sonic. Hideaki Kondoh is considered the first pen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
