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PETN
Pentaerythritol tetranitrate (PETN), also known as PENT, PENTA, (ПЕНТА, primarily in Russian) TEN, corpent, or penthrite (or, rarely and primarily in German, as nitropenta), is an explosive material. It is the nitrate ester of pentaerythritol, and is structurally very similar to nitroglycerin. Penta refers to the five carbon atoms of the neopentane skeleton. PETN is a very powerful explosive material with a relative effectiveness factor of 1.66. When mixed with a plasticizer, PETN forms a plastic explosive. Along with RDX it is the main ingredient of Semtex. PETN is also used as a vasodilator drug to treat certain heart conditions, such as for management of angina. History Pentaerythritol tetranitrate was first prepared and patented in 1894 by the explosives manufacturer Rheinisch-Westfälische Sprengstoff A.G. of Cologne, Germany. The production of PETN started in 1912, when the improved method of production was patented by the German government. PETN was used by the Germ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Material
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or BLEVE * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". Explosives may a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Effectiveness Factor
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a metric ton (1,000 kilograms) of TNT. In other words, for each gram of TNT exploded, (or 4184 joules) of energy is released. This convention intends to compare the destructiveness of an event with that of conventional explosive materials, of which TNT is a typical example, although other conventional explosives such as dynamite contain more energy. Kiloton and megaton The "kiloton (of TNT)" is a unit of energy equal to 4.184 terajoules (). The "megaton (of TNT)" is a unit of energy equal to 4.184 petajoules (). The kiloton and megaton of TNT have traditionally been used to describe the energy output, and hence the destructive power, of a nuclear weapon. The TNT equivalent appears in various nuclear weapon control treaties, and has bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semtex
Semtex is a general-purpose plastic explosive containing RDX and Pentaerythritol tetranitrate, PETN. It is used in commercial blasting, demolition, and in certain military applications. Semtex was developed and manufactured in Czechoslovakia, originally under the name B 1 and then under the "Semtex" designation since 1964, labeled as ''SEMTEX 1A'', since 1967 as ''SEMTEX H'', and since 1987 as ''SEMTEX 10''. Originally developed for Czechoslovak military use and export, Semtex eventually became popular with paramilitary groups and rebels or terrorism, terrorists because prior to 2000 it was extremely difficult to detect, as in the case of Pan Am Flight 103. Composition The composition of the two most common variants differ according to their use. The 1A (or 10) variant is used for drilling and blasting, mining, and is based mostly on crystalline Pentaerythritol tetranitrate, PETN. The versions 1AP and 2P are formed as hexagonal Explosive booster, booster charges; a special assem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mine Shell
A mine shell (from the German term ''Minengeschoß'', "mine shot"), also known as High-Explosive, High-Capacity (HEHC) in British military nomenclature, is a military explosive shell type characterized by thin (usually steel) shell walls and a correspondingly high quantity of explosives, much higher than the traditional high explosive shell type per caliber, meaning that mine shells trade fragmentation effect (due to the thinner shell walls) for a higher pressure wave effect when comparing to traditional high explosive shells. Mine shells were originally developed during the mid to late 1800s against fortresses prior to rebar but got a new role during World War II against air targets as reinforced fortresses had made the original use of the type obsolete around World War I. Effect, construction and use The mine shell is a more explosive version of the common high-explosive and high-explosive fragmentation shells, relying on inflicting damage primarily through the blast (pressu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilation
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is necessary for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentaerythritol
Pentaerythritol is an organic compound with the formula C(CH2OH)4. Classified as a polyol, it is a white solid. Pentaerythritol is a building block for the synthesis and production of explosives, plastics, paints, appliances, cosmetics, and many other commercial products. The word pentaerythritol is a blend of ''penta-'' in reference to its 5 carbon atoms and ''erythritol'', which also possesses 4 alcohol groups. Synthesis Pentaerythritol was first reported in 1891 by German chemist Bernhard Tollens and his student P. Wigand. It may be prepared via a base-catalyzed multiple-addition reaction between acetaldehyde and 3 equivalents of formaldehyde to give pentaerythrose (CAS: 3818-32-4), followed by a Cannizzaro reaction with a fourth equivalent of formaldehyde to give the final product. Uses Pentaerythritol is a versatile building block for the preparation of many compounds, particularly polyfunctionalized derivatives. applications include alkyd resins, varnishes, polyvinyl c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitroglycerin
Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, but the traditional name is retained. Invented in 1847 by Ascanio Sobrero, nitroglycerin has been used ever since as an active ingredient in the manufacture of explosives, namely dynamite, and as such it is employed in the construction, demolition, and mining industries. Since the 1880s, it has been used by militaries as an active ingredient and gelatinizer for nitrocellulose in some solid propellants such as cordite and ballistite. It is a major component in double-based smokeless propellants used by reloaders. Combined with nitrocellulose, hund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrate Ester
In organic chemistry, a nitrate ester is an organic functional group with the formula , where R stands for any organic residue. They are the esters of nitric acid and alcohols. A well-known example is nitroglycerin, which is not a ''nitro'' compound, despite its name. : Synthesis and reactions Nitrate esters are typically prepared by condensation of nitric acid and the alcohol: For example, the simplest nitrate ester, methyl nitrate, is formed by reaction of methanol and nitric acid in the presence of sulfuric acid: :CH3OH + HNO3 -> CH3ONO2 + H2O This condensation is sometimes called "nitroxylation". Explosive properties The thermal decomposition of nitrate esters mainly yields the gases molecular nitrogen (N2) and carbon dioxide. The considerable chemical energy of the detonation is due to the high strength of the bond in molecular nitrogen. This stoichiometry is illustrated by the equation for the detonation of nitroglycerin. : Illustrative of the highly sensitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastic Explosive
Plastic explosive is a soft and hand-moldable solid form of explosive material. Within the field of explosives engineering, plastic explosives are also known as putty explosives or blastics. Plastic explosives are especially suited for explosive demolition. Common plastic explosives include Semtex and C-4. The first manufactured plastic explosive was gelignite in 1875, invented by Alfred Nobel. Usage Plastic explosives are especially suited for explosive demolition of obstacles and fortifications by engineers, combat engineers and criminals as they can be easily formed into the best shapes for cutting structural members and have a high enough velocity of detonation and density for metal cutting work. An early use of plastic explosives was in the warhead of the Petard demolition mortar of the British Armoured Vehicle Royal Engineers (AVRE); said mortar was used to destroy concrete fortifications encountered during Operation Overlord (D-Day). The original use of Nobel 808 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromaticity
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturated compounds having single bonds, and other geometric or connective non-cyclic arrangements with the same set of atoms. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, but only aromatic rings have enhanced stability. The term ''aromaticity'' with this meaning is historically related to the concept of having an aroma, but is a distinct property from that meaning. Since the most common aromatic compounds are derivatives of benzene (an aromatic hydrocarbon common in petroleum and its distillates), the word ''aromatic'' occasionally refers informally to benzene derivatives, and so it was first defined. Nevertheless, many non-be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylformamide
Dimethylformamide is an organic compound with the formula ( CH3)2NC(O)H. Commonly abbreviated as DMF (although this initialism is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by sparging samples with an inert gas such as argon or by sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide, having two methyl groups in the place of the two hydrogens. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions. Structure and properties As for most amides, the spectroscopic evidence indicates partial double bond charact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutectic System
A eutectic system or eutectic mixture ( ) is a homogeneous mixture that has a melting point lower than those of the constituents. The lowest possible melting point over all of the mixing ratios of the constituents is called the ''eutectic temperature''. On a phase diagram, the eutectic temperature is seen as the eutectic point (see plot on the right). Non-eutectic mixture ratios would have different melting temperatures for their different constituents, since one component's lattice will melt at a lower temperature than the other's. Conversely, as a non-eutectic mixture cools down, each of its components would solidify (form a lattice) at a different temperature, until the entire mass is solid. Not all binary alloys have eutectic points, since the valence electrons of the component species are not always compatible, in any mixing ratio, to form a new type of joint crystal lattice. For example, in the silver-gold system the melt temperature ( liquidus) and freeze temperature (s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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