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Barium Nitrate
Barium nitrate is the inorganic compound with the chemical formula Ba( NO3)2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics. Manufacture, occurrence, and reactions Barium nitrate is manufactured by two processes that start with the main source material for barium, the carbonate. The first involves dissolving barium carbonate in nitric acid, allowing any iron impurities to precipitate, then filtered, evaporated, and crystallized. The second requires combining barium sulfide with nitric acid. It occurs naturally as the very rare mineral nitrobarite. At elevated temperatures, barium nitrate decomposes to barium oxide: : Applications Barium nitrate is used in the production of BaO-containing materials. Military Although no longer produced, Baratol is an explosive composed of barium nitrate, TNT and binder; the high density of barium nitrate results in baratol bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetone
Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a characteristic pungent odor. Acetone is miscibility, miscible with properties of water, water and serves as an important organic solvent in industry, home, and laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and for production of methyl methacrylate and bisphenol A, which are precursors to widely used plastics.Acetone World Petrochemicals report, January 2010Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. It is a common building block in organic chemistry. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermite
Thermite () is a pyrotechnic composition of powder metallurgy, metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic redox, reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as gunpowder, black powder. Thermites have diverse compositions. Fuels include aluminium, aluminum, magnesium, titanium, zinc, silicon, and boron. Aluminum is common because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. In a thermochemical survey comprising twenty-five metals and thirty-two metal oxides, 288 out of 800 binary combinations were characterized by adiabatic temperatures greater than 2000 K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Sulfate
Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 million tonnes, the decahydrate is a major commodity chemical product. It is mainly used as a filler in the manufacture of powdered home laundry detergents and in the Kraft process of paper pulping for making highly alkaline sulfides. Forms *Anhydrous sodium sulfate, known as the rare mineral thénardite, used as a drying agent in organic synthesis. *Heptahydrate sodium sulfate, a very rare form. *Decahydrate sodium sulfate, known as the mineral mirabilite, widely used by chemical industry. It is also known as Glauber's salt. History The decahydrate of sodium sulfate is known as Glauber's salt after the Netherlands, Dutch–Germany, German chemist and apothecary Johann Rudolf Glauber (1604–1670), who discovered it in Austrian spring water i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsom Salts
Epsomite, Epsom salt, or magnesium sulfate heptahydrate, is a hydrous magnesium sulfate mineral with formula . Physical properties Epsomite crystallizes in the orthorhombic system. The normal form is as massive encrustations, while acicular or fibrous crystals are rarely found. It is colorless to white with tints of yellow, green and pink. It is a soft mineral with variable Mohs hardness around 2.0~2.5, and it has a low specific gravity It is readily soluble in water, and absorbs water from the air. It converts to hexahydrate with the loss of one water molecule and a switch to monoclinic structure. The epsomite group includes solid solution series with morenosite (·) and goslarite (·). Etymology It was first systematically described in 1806 for an occurrence near Epsom, Surrey, England, after which it was named. It has been also referred to as "cave cotton" when in its fibrous form. Occurrence Epsomite forms as encrustations or efflorescences on limestone cave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many are prepared from that acid. Spelling "Sulfate" is the spelling recommended by IUPAC, but "sulphate" was traditionally used in British English. Structure The sulfate anion consists of a central sulfur atom surrounded by four equivalent oxygen atoms in a tetrahedral arrangement. The symmetry of the isolated anion is the same as that of methane. The sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the −2 state. The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, , which is in turn the conjugate base of , sulfuric acid. Organic sulfate esters, such as dimethyl sulfate, are covalent compounds and esters of sulfuric acid. The tetrahedral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell ( cytotoxicity) or an organ such as the liver ( hepatotoxicity). Sometimes the word is more or less synonymous with poisoning in everyday usage. A central concept of toxicology is that the effects of a toxicant are dose-dependent; even water can lead to water intoxication when taken in too high a dose, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect. Toxicity is species-specific, making cross-species analysis problematic. Newer paradigms and metrics are evolving to bypass animal testing, while maintaining the concept of toxicity endpoints. Etymology In Ancient Greek medical literature, the adjective ''τοξικόν'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrotechnic
Pyrotechnics is the science and craft of creating fireworks, but also includes safety matches, oxygen candles, explosive bolts (and other fasteners), parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. This trade relies upon self-contained and self-sustained exothermic chemical reactions to make heat, light, gas, smoke and/or sound. The name comes from the Greek words ''pyr'' (πυρ; 'fire') and ''technikós'' (τεχνικός; 'artistic'). Improper use of pyrotechnics could lead to pyrotechnic accidents. People responsible for the safe storage, handling, and functioning of pyrotechnic devices are known as pyrotechnicians. Proximate pyrotechnics Explosions, flashes, smoke, flames, fireworks and other pyrotechnic-driven effects used in the entertainment industry are referred to as proximate pyrotechnics. Proximate refers to the pyrotechnic device's location relative to an audience. In the majority of jurisdictions, special tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It takes the form of an evacuated tubular envelope of glass or sometimes metal containing electrodes connected to external connection pins. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental Electronics, electronic functions such as signal amplifier, amplification and current Rectifier, rectification. Non-thermionic types such as vacuum phototubes achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light and measurement of its intensity. In both types the electrons are accelerated from the cathode to the anode by the electric field in the tube. The first, and simplest, vacuum tube, the diode or Flem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Britain
The Battle of Britain () was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defended the United Kingdom (UK) against large-scale attacks by Nazi Germany's air force, the Luftwaffe. It was the first major military campaign fought entirely by air forces."92 Squadron – Geoffrey Wellum." ''Battle of Britain Memorial Flight'' via ''raf.mod.uk.''. Retrieved: 17 November 2010, archived 2 March 2009. It takes its name from This was their finest hour, the speech given by Prime Minister Winston Churchill to the House of Commons of the United Kingdom, House of Commons on 18 June: "What Maxime Weygand, General Weygand called the 'Battle of France' is over. I expect that the Battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and other Allies of World War II, Allied countries before, during, and after World War II. It was the only British fighter produced continuously throughout the war. The Spitfire remains popular among enthusiasts. Around List of surviving Supermarine Spitfires, 70 remain airworthy, and many more are static exhibits in aviation museums throughout the world. The Spitfire was a short-range, high-performance interceptor aircraft designed by R. J. Mitchell, chief designer at Supermarine Aviation Works, which operated as a subsidiary of Vickers-Armstrong from 1928. Mitchell modified the Spitfire's distinctive elliptical wing (designed by Beverley Shenstone) with innovative sunken rivets to have the thinnest possible cross-section, achieving a potential top speed greater than that of several contemporary fighter aircraft, including the Hawker Hurricane. Mitchell continued to refine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawker Hurricane
The Hawker Hurricane is a British single-seat fighter aircraft of the 1930s–40s which was designed and predominantly built by Hawker Aircraft Ltd. for service with the Royal Air Force (RAF). It was overshadowed in the public consciousness by the Supermarine Spitfire during the Battle of Britain in 1940, but the Hurricane inflicted 60% of the losses sustained by the ''Luftwaffe'' in the campaign, and fought in all the major theatres of the Second World War. The Hurricane originated from discussions between RAF officials and aircraft designer Sir Sydney Camm about a proposed monoplane derivative of the Hawker Fury biplane in the early 1930s. Despite an institutional preference for biplanes and lack of interest by the Air Ministry, Hawker refined its monoplane proposal, incorporating several innovations which became critical to wartime fighter aircraft, including retractable landing gear and the more powerful Rolls-Royce Merlin engine. The Air Ministry ordered Hawker's ''Interce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interceptor Aircraft
An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are capable of being or are employed as both "standard" air superiority fighters and as interceptors are sometimes known as fighter-interceptors. In the post-World War 2 jet age, there are two general classes of interceptor: light fighters, designed for high performance over short range; and heavy fighters, which are intended to operate over longer ranges, in contested airspace and adverse meteorological conditions. While the second type was exemplified historically by specialized night fighter and all-weather interceptor designs, the integration of mid-air refueling, satellite navigation, on-board radar, and beyond visual range (BVR) missile systems since the 1960s has allowed most frontline fighter designs to fill the roles once reserve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
