|
Shelling Of Yeonpyeong
Shelling may refer to: * Shell (projectile), explosive used in wars * Searching for seashells * Shelling (topology) In mathematics, a shelling of a simplicial complex is a way of gluing it together from its maximal simplices (simplices that are not a face of another simplex) in a well-behaved way. A complex admitting a shelling is called shellable. Definition ... * Wheelset deformation, that occur when the wheel has been worn out * Shelling (fishing), a fishing strategy used by dolphins. See also * {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell (projectile)
A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage sometimes includes large solid kinetic projectiles that is properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used. All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called ''grenades'', derived from the French word for pomegranate, so called because of the similarity of shape and that the multi-seeded fruit resembles the powder-filled, fragmentizing bomb. Words cognate with ''grenade'' are still used for an artillery or mortar projectile in some European languages. Shells are usually large-caliber projectiles fired by artillery, armored fighting vehicles (e.g. tanks, assault guns, and mortar carriers), warships, and autocannons. The shape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seashell
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have decomposed or been eaten by another animal. A seashell is usually the exoskeleton of an invertebrate (an animal without a backbone), and is typically composed of calcium carbonate or chitin. Most shells that are found on beaches are the shells of marine mollusks, partly because these shells are usually made of calcium carbonate, and endure better than shells made of chitin. Apart from mollusk shells, other shells that can be found on beaches are those of barnacles, horseshoe crabs and brachiopods. Marine annelid worms in the family Serpulidae create shells which are tubes made of calcium carbonate cemented onto other surfaces. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shelling (topology)
In mathematics, a shelling of a simplicial complex is a way of gluing it together from its maximal simplices (simplices that are not a face of another simplex) in a well-behaved way. A complex admitting a shelling is called shellable. Definition A ''d''-dimensional simplicial complex is called pure if its maximal simplices all have dimension ''d''. Let \Delta be a finite or countably infinite simplicial complex. An ordering C_1,C_2,\ldots of the maximal simplices of \Delta is a shelling if the complex :B_k:=\Big(\bigcup_^C_i\Big)\cap C_k is pure and of dimension \dim C_k-1 for all k=2,3,\ldots. That is, the "new" simplex C_k meets the previous simplices along some union B_k of top-dimensional simplices of the boundary of C_k. If B_k is the entire boundary of C_k then C_k is called spanning. For \Delta not necessarily countable, one can define a shelling as a well-ordering of the maximal simplices of \Delta having analogous properties. Properties * A shellable complex is homotop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheelset (rail Transport)
A wheelset is a pair of railroad vehicle wheels mounted rigidly on an axle such that both wheels rotate in unison. Wheelsets are often mounted in a bogie ("truck" in North America) – a pivoted frame assembly holding at least two wheelsets – at each end of the vehicle. Most modern freight cars and passenger cars have bogies each with two wheelsets, but three wheelsets (or more) are used in bogies of freight cars that carry heavy loads, and three-wheelset bogies are under some passenger cars. Four-wheeled goods wagons that were once near-universal in Europe and Great Britain and their colonies have only two wheelsets; in recent decades such vehicles have become less common as trainloads have become heavier. Conical wheel-tread Most train wheels have a conical taper of about 1 in 20 to enable the wheelset to follow curves with less chance of the wheel flanges coming in contact with the rail sides, and to reduce curve resistance. The rails generall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
