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Detonated
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with speeds in the range of 1 km/sec and differ from deflagrations which have subsonic flame speeds in the range of 1 m/sec. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. The velocity of detonation in solid and liquid explosives is much higher than that in gaseous ones, which allows the wave system to be observed with greater detail (higher resolution). A very wide variety of fuels may occur as gases (e.g. hydrogen), droplet fogs, or dust suspensions. In addition to dioxygen, oxidants can include halogen compounds, ozone, hydrogen peroxide and oxides of nitrogen. Gaseous detonations are often associated with a mixture of fuel and oxidant in a composition somewhat below conventional flammabilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonation Velocity
Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. Explosive velocities are always faster than the local speed of sound in the material. If the explosive is confined before detonation, such as in an artillery shell, the force produced is focused on a much smaller area, and the pressure is significantly intensified. This results in an explosive velocity that is higher than if the explosive had been detonated in open air. Unconfined velocities are often approximately 70 to 80 percent of confined velocities. Explosive velocity is increased with smaller particle size (i.e., increased spatial density), increased charge diameter, and increased confinement (i.e., higher pressure). Typical detonation velocities for organic dust mixtures range from 1400–1650m/s. Gas explosions can either deflagrate or detonate based on confinement; detonation velocities are generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNT Detonation On Kaho'olawe Island During Operation Sailor Hat, Shot Bravo, 1965
Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the TNT equivalent, standard comparative convention of bombs and asteroid impacts. In chemistry, TNT is used to generate Charge transfer complex, charge transfer salts. History TNT was first prepared in 1863 by Germany, German chemist Julius Wilbrand and originally used as a yellow dye. Its potential as an explosive was not recognized for three decades, mainly because it was too difficult to detonate because it was less sensitive than alternatives. Its explosive properties were first discovered in 1891 by another German chemist, Carl Häussermann. TNT can be safely poured when liquid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Von Neumann
John von Neumann (; hu, Neumann János Lajos, ; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. He was regarded as having perhaps the widest coverage of any mathematician of his time and was said to have been "the last representative of the great mathematicians who were equally at home in both pure and applied mathematics". He integrated pure and applied sciences. Von Neumann made major contributions to many fields, including mathematics (foundations of mathematics, measure theory, functional analysis, ergodic theory, group theory, lattice theory, representation theory, operator algebras, matrix theory, geometry, and numerical analysis), physics (quantum mechanics, hydrodynamics, ballistics, nuclear physics and quantum statistical mechanics), economics ( game theory and general equilibrium theory), computing ( Von Neumann architecture, linear programming, numerical meteo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Louis Le Chatelier
Henry Louis Le Chatelier (; 8 October 1850 – 17 September 1936) was a French chemist of the late 19th and early 20th centuries. He devised Le Chatelier's principle, used by chemists and chemical engineers to predict the effect a changing condition has on a system in chemical equilibrium. Early life Le Chatelier was born on 8 October 1850 in Paris and was the son of French materials engineer Louis Le Chatelier and Louise Durand. His father was an influential figure who played important roles in the birth of the French aluminium industry, the introduction of the Martin-Siemens processes into the iron and steel industries, and the rise of railway transportation. Le Chatelier's father profoundly influenced his son's future. Henry Louis had one sister, Marie, and four brothers, Louis (1853–1928), Alfred (1855–1929), George (1857–1935), and André (1861–1929). His mother raised the children by regimen, described by Henry Louis: "I was accustomed to a very strict discipline: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Welding
Explosion welding (EXW) is a solid state (solid-phase) process where welding is accomplished by accelerating one of the components at extremely high velocity through the use of chemical explosives. This process is often used to clad carbon steel or aluminium plate with a thin layer of a harder or more corrosion-resistant material (e.g., stainless steel, nickel alloy, titanium, or zirconium). Due to the nature of this process, producible geometries are very limited. Typical geometries produced include plates, tubing and tube sheets. Development Unlike other forms of welding such as arc welding (which was developed in the late 19th century), explosion welding was developed relatively recently, in the decades after World War II. Its origins, however, go back to World War I, when it was observed that pieces of shrapnel sticking to armor plating were not only embedding themselves, but were actually being welded to the metal. Since the extreme heat involved in other forms of welding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearm
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the Siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stability. Modern firearms can be described by their caliber ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semimetal
A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band. According to electronic band theory, solids can be classified as insulators, semiconductors, semimetals, or metals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap. For insulators, the magnitude of the band gap is larger (e.g., > 4 eV) than that of a semiconductor (e.g., < 4 eV). Because of the slight overlap between the conduction and valence bands, semimetals have no band gap and a negligible at the Fermi level. A metal, by contrast, has an appreciable density of states at the Fermi level because the conduction band is partially filled. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZND Theory
The ZND detonation model is a one-dimensional model for the process of detonation of an explosive. It was proposed during World War II independently by Y. B. Zel'dovich, John von Neumann, and Werner Döring, hence the name. This model admits finite-rate chemical reactions and thus the process of detonation consists of the following stages. First, an infinitesimal In mathematics, an infinitesimal number is a quantity that is closer to zero than any standard real number, but that is not zero. The word ''infinitesimal'' comes from a 17th-century Modern Latin coinage ''infinitesimus'', which originally referr ...ly thin shock wave compresses the explosive to a high pressure called the von Neumann spike. At the von Neumann spike point the explosive still remains unreacted. The spike marks the onset of the zone of exothermic chemical reaction, which finishes at the Chapman–Jouguet state. After that, the detonation products expand backward. In the reference frame in which the shoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aleksandr Solomonovich Kompaneets
Alexander Solomonovich Kompaneyets (Russian: Александр Соломонович Компанеец) was born on January 4, 1914 in Ekaterinoslav, Russian Empire (now Dnipro, Ukraine) and died on August 19, 1974 in Palanga, Lithuania. He was a prominent physicist, author of a number of textbooks, and collaborator on the Soviet atomic bomb project who lived mainly in Moscow. Life Kompaneyets was a student of Lev Landau in Kharkiv in the 1930s, where he dealt with solid state physics (electrical conductivity in metals and semiconductors). In 1936 he received his doctorate (candidate title) and habilitated in 1939 (Russian doctorate). He was a professor at the Institute of Chemical Physics at the Russian Academy of Sciences in Moscow (where he worked from 1946 until the end of his life) and is best known for his introductory textbook on theoretical physics. He also dealt with the physics of detonation, which he wrote about in a book with Yakov Zeldovich, and generally about ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
