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Detonate
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 about 1 km/sec and differ from deflagrations which have subsonic flame speeds about 1 m/sec. Detonation may form from an explosion of fuel-oxidizer mixture. Compared with deflagration, detonation doesn't need to have an external oxidizer. Oxidizers and fuel mix when deflagration occurs. Detonation is more destructive than deflagrations. In detonation, the flame front travels through the air-fuel faster than sound; while in deflagration, the flame front travels through the air-fuel slower than sound. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. TNT, dynamite, and C4 are examples of high power explosives that detonate. The velocity of detonation in solid and liquid explosiv ... [...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 higher 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 to 1650m/s. Gas explosions can either deflagrate or detonate based on confinement; detonation velocities are ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Von Neumann
John von Neumann ( ; ; December 28, 1903 – February 8, 1957) was a Hungarian and American mathematician, physicist, computer scientist and engineer. Von Neumann had perhaps the widest coverage of any mathematician of his time, integrating Basic research, pure and Applied science#Applied research, applied sciences and making major contributions to many fields, including mathematics, physics, economics, computing, and statistics. He was a pioneer in building the mathematical framework of quantum physics, in the development of functional analysis, and in game theory, introducing or codifying concepts including Cellular automaton, cellular automata, the Von Neumann universal constructor, universal constructor and the Computer, digital computer. His analysis of the structure of self-replication preceded the discovery of the structure of DNA. During World War II, von Neumann worked on the Manhattan Project. He developed the mathematical models behind the explosive lense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deflagration
Deflagration (Lat: ''de + flagrare'', 'to burn down') is subsonic combustion in which a pre-mixed flame propagates through an explosive or a mixture of fuel and oxidizer. Deflagrations in high and low explosives or fuel–oxidizer mixtures may transition to a detonation depending upon confinement and other factors. Most fires found in daily life are diffusion flames. Deflagrations with flame speeds in the range of 1 m/s differ from detonations which propagate supersonically with detonation velocities in the range of km/s. Applications Deflagrations are often used in engineering applications when the force of the expanding gas is used to move an object such as a projectile down a barrel, or a piston in an internal combustion engine. Deflagration systems and products can also be used in mining, demolition and stone quarrying via gas pressure blasting as a beneficial alternative to high explosives. Terminology of explosive safety When studying or discussing explosive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion
An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated by a slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a Volcano, volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. wikt:subsonic, Subsonic explosions are created by low explosives through a slower combustion process known as deflagration. Causes For an explosion to occur, there must be a rapid, forceful expansion of matter. There are numerous ways this can happen, both natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozone
Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lower atmosphere to (dioxygen). Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth's atmosphere. It is present in very low concentrations throughout the atmosphere, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation. Ozone's odor is reminiscent of chlorine, and detectable by many people at concentrations of as little as in air. Ozone's O3 chemical structure, structure was determined in 1865. The molecule was later proven to have a bent structure and to be weakly diamagnetism, diamagnetic. At standard temperature and pressure, ozone is a pale blue gas that condenses at cryogenic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNT Detonation On Kaho'olawe Island During Operation Sailor Hat, Shot Bravo, 1965
Troponin T (shortened TnT or TropT) is a part of the troponin complex, which are proteins integral to the contraction of skeletal and heart muscles. They are expressed in skeletal and cardiac myocytes. Troponin T binds to tropomyosin and helps position it on actin, and together with the rest of the troponin complex, modulates contraction of striated muscle. The cardiac subtype of troponin T is especially useful in the laboratory diagnosis of heart attack because it is released into the blood-stream when damage to heart muscle occurs. It was discovered by the German physician Hugo A. Katus at the University of Heidelberg, who also developed the troponin T assay. Subtypes * Slow skeletal troponin T1, TNNT1 (19q13.4, ) * Cardiac troponin T2, TNNT2 (1q32, ) * Fast skeletal troponin T3, TNNT3 (11p15.5, ) Reference values The 99th percentile cutoff for cardiac troponin T (cTnT) is 0.01 ng/mL. The reference range for the high sensitivity troponin T is a normal 52 ng/L. Backgroun ... [...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 Lithuania, officially the Republic of Lithuania, is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea, bordered by Latvia to the north, Belarus to the east and south, P .... 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Werner Döring
Werner Döring (2 September 1911, Berlin – 6 June 2006, Malente) was a German theoretical physicist. From 1963 until his retirement in 1977, he was a full professor (Ordinarius) at the Universität Hamburg. His main interest was the theory of magnetism. His textbooks on theoretical physics have influenced several generations of students. He is remembered today for the Becker–Döring theory of nucleation of liquid droplets in solids (in condensed matter physics), and for the Zel'dovich–von Neumann–Döring detonation model (in explosives engineering). Selected publications * R. Becker, W. Döring, ''Kínetische Behandlung der Keimbildung in übersättigten Dämpfen'', Annalen der Physik 416, 719-752 (1935); https://doi.org/10.1002/andp.19354160806 * R. Becker, W. Döring, ''Ferromagnetismus'', Berlin, Springer 1939 * W. Döring, ''Einführung in die Theoretische Physik'' (Sammlung Göschen; fünf Bände: Mechanik, Elektrodynamik, Optik, Thermodynamik, Statistische Mechanik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yakov B
Yakov (alternative spellings: Jakov or Iakov, cyrl, Яков) is a Russian or Hebrew variant of the given names Jacob and James. People also give the nickname Yasha ( cyrl, Яша) or Yashka ( cyrl, Яшка) used for Yakov. Notable people People named Yakov * Yakov Blumkin (1900–1929), a Left Socialist-Revolutionary * Yakov Cherevichenko (1894–1976), Soviet military leader * Yakov Chubin (1893–1956), Soviet official * Yakov Dzhugashvili (1907–1943), the oldest son of Joseph Stalin * Yakov Eliashberg (born 1946), American mathematician * Yakov Ehrlich (born 1988), former Russian football player * Yakov Eshpay (1890–1963), Soviet composer * Yakov Estrin (1923–1987), Soviet chess player * Yakov Fedorenko (1896–1947), Soviet military leader * Yakov Frenkel (1894–1952), Soviet physicist * Yakov Fliyer (1912–1977), Soviet pianist * Yakov Gakkel (1901–1965), Soviet oceanographer * Yakov "Yan" Gamarnik (1894–1937), Soviet official * Yakov Grot (1812–1893), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semimetal
A semimetal is a material with a small energy overlap between the bottom of the Electrical conduction, conduction Electronic band structure, band and the top of the valence band, but they do not overlap in momentum space. According to Band theory, electronic band theory, solids can be classified as Insulator (electricity), 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 Electronvolt, 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 small density of states 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. Temperature dependency The insulating/semiconducting st ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chapman–Jouguet Condition
The Chapman–Jouguet condition holds approximately in detonation waves in high explosives. It states that the detonation propagates at a velocity at which the reacting gases just reach sonic velocity (in the frame of the leading shock wave) as the reaction ceases. David Chapman and Émile Jouguet originally (c. 1900) stated the condition for an infinitesimally thin detonation. A physical interpretation of the condition is usually based on the later modelling (c. 1943) by Yakov Borisovich Zel'dovich, John von Neumann, and Werner Döring (the so-called ZND detonation model). In more detail (in the ZND model) in the frame of the leading shock of the detonation wave, gases enter at supersonic velocity and are compressed through the shock to a high-density, subsonic flow. This sudden change in pressure initiates the chemical (or sometimes, as in steam explosions, physical) energy release. The energy release re-accelerates the flow back to the local speed of sound. It can be sho ... [...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 Yakov Zeldovich, 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 infinitesimally 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 condition The Chapman–Jouguet condition holds approximately in detonation waves in high explosives. It states that the detonation propagates at a velocity at which the reacting gases just reach sonic velocity (in the frame of the leading shock wave) as t .... After that, the detonation products expand backward. In the reference frame in which the sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
