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Shock Sensitivity
Shock sensitivity is a comparative measure of the sensitivity to sudden compression (by impact or blast) of an explosive chemical compound. Determination of the shock sensitivity of a material intended for practical use is one important aspect of safety testing of explosives. A variety of tests and indices are in use, of which one of the more common is the Rotter Impact Test, with results expressed as FoI ( Figure of Insensitivity.) In addition, various "gap tests" are used to measure sensitivity to blast shock. Sensitivities vary widely A few materials such as nitrogen triiodide cannot be touched at all without detonating, and so are of purely academic interest. Some other compounds with a high sensitivity to shock, such as nitroglycerin and acetone peroxide, may detonate from a firm jolt and so cannot be legally transported in pure form. Acetone peroxide is often used by amateurs and terrorists as a means to detonate other explosives as well as acting as the main blasting ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive
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 boiling liquid expanding vapor explosion * 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 ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Gel Explosive
A water-gel explosive is a fuel-sensitized explosive mixture consisting of an aqueous ammonium nitrate solution that acts as the oxidizer. Water gels that are cap-insensitive are referred to under United States safety regulations as blasting agents. Water gel explosives have a jelly-like consistency and come in sausage-like packing stapled shut on both sides. Water-gel explosives have almost completely displaced dynamite, becoming the most-used civil blasting agents. Composition Water gels usually have many different ingredients. They contain a gelatinizing agent, also known as a thickener, that modifies their consistency, ranging from easily pourable gels to hard solids. Polyvinyl alcohol, guar gum, dextran gums, and urea-formaldehyde resins are the typical gelling agents. Guar, specifically, is a gelling agent used for the aqueous portion of the water gel explosives. The primary component of water gels is methylamine nitrate. Methylamine nitrate is the salt formed by the ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catastrophic Failure
A catastrophic failure is a sudden and total failure from which recovery is impossible. Catastrophic failures often lead to cascading systems failure. The term is most commonly used for structural failures, but has often been extended to many other disciplines in which total and irrecoverable loss occurs, such as a head crash occurrence on a hard disk drive. For example, catastrophic failure can be observed in steam turbine rotor failure, which can occur due to peak stress on the rotor; stress concentration increases up to a point at which it is excessive, leading ultimately to the failure of the disc. In firearms, catastrophic failure usually refers to a rupture or disintegration of the barrel or receiver of the gun when firing it. Some possible causes of this are an out-of-battery gun, an inadequate headspace, the use of incorrect ammunition, the use of ammunition with an incorrect propellant charge, a partially or fully obstructed barrel, or weakened metal in the barrel o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activation Energy
In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. The activation energy (''E''a) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). Activation energy can be thought of as a magnitude of the potential barrier (sometimes called the energy barrier) separating minima of the potential energy surface pertaining to the initial and final thermodynamic state. For a chemical reaction to proceed at a reasonable rate, the temperature of the system should be high enough such that there exists an appreciable number of molecules with translational energy equal to or greater than the activation energy. The term "activation energy" was introduced in 1889 by the Swedish scientist Svante Arrhenius. Other uses Although less commonly used, activation energy also applies to nuclear reactions and various other physical phenomena. Temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Party Poppers
A party popper is a handheld pyrotechnic device commonly used at parties. It emits a loud popping noise by means of a small, friction-actuated explosive charge that is activated by pulling a string. The explosive charge comes from a very small amount of Armstrong's mixture (a highly sensitive explosive) in the neck of the bottle-like shape. In some party poppers, the explosive charge is replaced by compressed air. In party poppers with an explosive charge, there are less than of explosive. The streamers are non-flammable for safe use. The charge or compressed air blows out some confetti or streamers and emits a popping sound. The charge is often composed of red phosphorus and strong oxidizer, such as potassium chlorate and potassium perchlorate. There are also party popper revolvers on the market, which use a Speedloader — style cartridge filled with six-party popper charges inserted into a normally colourful plastic device loosely resembling a pistol or revolver. Its functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cap Gun
A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. The origin of the word "cap" comes from the Old French word "chapeau" which means "head covering". Over time, the word has evolved and changed its meaning, but it still retains its association with headwear. Caps typically have a visor, or no brim at all. They are popular in casual and informal settings, and are seen in sports and fashion. They are typically designed for warmth, and often incorporate a visor to block sunlight from the eyes. They come in many shapes, sizes, and are of different brands. Baseball caps are one of the most common types of cap. Types * Ascot cap * Ayam * Baggy green * Balmoral * Beanie (North America) * Bearskin * Beret * Biretta * Busby * Canterbury cap * Cap and bells * Cap of maintenance * Casquette * Caubeen * Caul * Coif * Combination cap (also known as a service cap) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fireworks
Fireworks are Explosive, low explosive Pyrotechnics, pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large number of devices in an outdoor setting. Such displays are the focal point of many cultural and religious Celebration (party), celebrations, though mismanagement could lead to List of fireworks accidents and incidents, fireworks accidents. Fireworks take many forms to produce four primary effects: noise, light, smoke, and floating materials (confetti most notably). They may be designed to burn with colored flames and sparks including red, orange, yellow, green, blue, purple and silver. They are generally classified by where they perform, either 'ground' or 'aerial'. Aerial fireworks may have their own Air propulsion, propulsion (skyrocket) or be shot into the air by a Mortar (weapon), mortar (aerial shell). Most fireworks consist of a paper or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonator
A detonator is a device used to make an explosive or explosive device explode. Detonators come in a variety of types, depending on how they are initiated (chemically, mechanically, or electrically) and details of their inner working, which often involve several stages. Types of detonators include non-electric and electric. Non-electric detonators are typically stab or pyrotechnic while electric are typically "hot wire" (low voltage), exploding bridge wire (high voltage) or explosive foil (very high voltage). The original electric detonators invented in 1875 independently by Julius Smith and Perry Gardiner used mercury fulminate as the primary explosive. Around the turn of the century performance was enhanced in the Smith-Gardiner blasting cap by the addition of 10-20% potassium chlorate. This compound was superseded by others: lead azide, lead styphnate, some aluminium, or other materials such as DDNP ( diazo dinitro phenol) to reduce the amount of lead emitted into the atm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell (projectile)
A shell, in a modern military context, is a projectile whose payload contains an explosive, incendiary device, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. A shell can hold a tracer ammunition, tracer. All explosive- and incendiary-filled projectiles, particularly for mortar (weapon), mortars, were originally called ''grenades'', derived from the French language, 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 vehicle, armoured fighting vehicles (e.g. tanks, assault guns, and mortar carriers), warships, and autocannons. The shape is usually a cylinder (geometry), cylinder topped by an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gelignite
Gelignite (), also known as blasting gelatin or simply "jelly", is an explosive material consisting of collodion-cotton (a type of nitrocellulose or guncotton) dissolved in either nitroglycerine or nitroglycol and mixed with wood pulp and Potassium nitrate, saltpetre (sodium nitrate or potassium nitrate). It was invented in 1875 by Swedish chemist Alfred Nobel, who also invented dynamite. It is more stable than dynamite, but can still suffer from "sweating" or leaching out nitroglycerine. Its composition makes it plastic explosive, easily moldable and safe to handle without protection, as long as it is not near anything capable of detonating it. One of the cheapest explosives, it burns slowly and cannot explode without a detonator, so it can be stored safely. In the United Kingdom, an explosives certificate, issued by the local Chief Officer of Police, is required for possession of gelignite. Due to its widespread civilian use in Quarry, quarries and mining, it has historically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken or new bonds formed or both. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
