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Barium Ferrite
Barium Ferrite (magnet), ferrite, or Barium hexaferrite, is a chemical compound with the chemical formula, formula (), sometimes abbreviated BaFe, BaM. This and related Ferrite (magnet), ferrite materials are components in magnetic stripe cards and loudspeaker magnets. BaFe is described as . The centers are Ferrimagnetism, ferrimagnetically coupled, and one unit cell of BaM has a net magnetic moment of 40. This area of technology is usually considered to be an application of the related fields of materials science and solid state chemistry. Barium ferrite is a highly magnetic material, has a high packing density, and is a metal oxide. Studies of this material date at least as far back as 1931, and it has found applications in magnetic card strips, speakers, and magnetic tapes. One area in particular it has found success in is long-term data storage; the material is magnetic, resistant to temperature change, corrosion and oxidization. Chemical structure The centers, with a Crys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrite (magnet)
A ferrite is one of a family of iron oxide-containing magnetic ceramic materials. They are ferrimagnetic, meaning they are attracted by magnetic fields and can be Magnetization, magnetized to become permanent magnets. Unlike many ferromagnetic materials, most ferrites are not electrically electrical conductor, conductive, making them useful in applications like magnetic cores for transformers to suppress eddy currents. Ferrites can be divided into two groups based on their magnetic coercivity, their resistance to being demagnetized: "Hard" ferrites have high coercivity, so are difficult to demagnetize. They are used to make permanent magnets for applications such as refrigerator magnets, loudspeakers, and small electric motors. "Soft" ferrites have low coercivity, so they easily change their magnetization and act as conductors of magnetic fields. They are used in the electronics industry to make efficient magnetic cores called ferrite cores for high-frequency inductors, transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal Close-packed
In geometry, close-packing of equal spheres is a dense arrangement of congruent spheres in an infinite, regular arrangement (or Lattice (group), lattice). Carl Friedrich Gauss proved that the highest average density – that is, the greatest fraction of space occupied by spheres – that can be achieved by a Lattice (group), lattice packing is :\frac \approx 0.74048. The same packing density can also be achieved by alternate stackings of the same close-packed planes of spheres, including structures that are aperiodic in the stacking direction. The Kepler conjecture states that this is the highest density that can be achieved by any arrangement of spheres, either regular or irregular. This conjecture was proven by Thomas Callister Hales, Thomas Hales. The highest density is so far known only for 1, 2, 3, 8, and 24 dimensions. Many crystal structures are based on a close-packing of a single kind of atom, or a close-packing of large ions with smaller ions filling the spaces between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared, infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. It is a trace gas Carbon dioxide in Earth's atmosphere, in Earth's atmosphere at 421 parts per million (ppm), or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. Burning fossil fuels is the main cause of these increased concentrations, which are the primary cause of climate change.IPCC (2022Summary for pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Carbonate
Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds. Preparation Barium carbonate is made commercially from barium sulfide by treatment with sodium carbonate at 60 to 70 °C ( soda ash method) or, more commonly carbon dioxide at 40 to 90 °C: In the soda ash process, an aqueous solution of barium sulfide is treated with sodium carbonate: : Reactions Barium carbonate reacts with acids such as hydrochloric acid to form soluble barium salts, such as barium chloride: : Pyrolysis of barium carbonate gives barium oxide. Uses It is mainly used to remove sulfate impurities from feedstock of the chlor-alkali process. Otherwise it is a common precursor to barium-containing compounds such as ferrites. Other uses Barium carbonate is widely used in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterworths
LexisNexis is an American data analytics company headquartered in New York, New York. Its products are various databases that are accessed through online portals, including portals for computer-assisted legal research (CALR), newspaper search, and consumer information. During the 1970s, LexisNexis began to make legal and journalistic documents more accessible electronically. the company had the world's largest electronic database for legal and public-records–related information. The company is a subsidiary of RELX. History LexisNexis is owned by RELX (formerly known as Reed Elsevier). According to Trudi Bellardo Hahn and Charles P. Bourne, LexisNexis (originally founded as LEXIS) is historically significant because it was the first of the early information services to both envision and actually bring about a future in which large populations of end users would directly interact with computer databases, rather than going through professional intermediaries like librarians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron(III) Oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula . It occurs in nature as the mineral hematite, which serves as the primary source of iron for the steel industry. It is also known as red iron oxide, especially when used in pigments. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (), which also occurs naturally as the mineral magnetite. Iron(III) oxide is often called rust, since rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as hydrous ferric oxide. Ferric oxide is readily attacked by even weak acids. It is a weak oxidising agent, most famously when reduced by aluminium in the thermite reaction. Structure can be obtained in various polymorphs. In the primary polymorph, α, iron adopts octahedral coordination geometry. That is, each Fe center is bound to six oxygen ligands. In t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Carbonate
Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds. Preparation Barium carbonate is made commercially from barium sulfide by treatment with sodium carbonate at 60 to 70 °C ( soda ash method) or, more commonly carbon dioxide at 40 to 90 °C: In the soda ash process, an aqueous solution of barium sulfide is treated with sodium carbonate: : Reactions Barium carbonate reacts with acids such as hydrochloric acid to form soluble barium salts, such as barium chloride: : Pyrolysis of barium carbonate gives barium oxide. Uses It is mainly used to remove sulfate impurities from feedstock of the chlor-alkali process. Otherwise it is a common precursor to barium-containing compounds such as ferrites. Other uses Barium carbonate is widely used in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcination
Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally for the purpose of removing impurities or volatile substances and/or to incur thermal decomposition. The root of the word calcination refers to its most prominent use, which is to remove carbon from limestone (calcium carbonate) through combustion to yield calcium oxide (quicklime). This calcination reaction is CaCO3(s) → CaO(s) + CO2(g). Calcium oxide is a crucial ingredient in modern cement, and is also used as a chemical flux in smelting. Industrial calcination generally emits carbon dioxide (). A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing (550–1150 °C, or 1000–2100 °F) within a controlled atmosphere. Etymology The process of calcination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bentham Science Publishers
Bentham Science Publishers is a company that publishes scientific, technical, and medical journals and e-books. It publishes over 120 subscription-based academic journals and around 40 open access journals. As of 2023, 66 Bentham Science journals have received JCR impact factors, and they are a member of the Committee on Publication Ethics. ''Bentham Open'', its open access division, has received criticism for questionable peer-review practices as well as invitation spam; it was listed as a "potential, possible, or probable predatory scholarly open access publisher" in Jeffrey Beall's list of predatory publishers, before the list went defunct. History Bentham was incorporated in 1994 by Atta-ur-Rahman and his friend Matthew Honan as a private business entity at the Sharjah Airport International Free Trade Zone in the United Arab Emirates. An investigative profile from ''Sujag'' notes the publisher to have operated out of Pakistan — for the first six years, from the premise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Citrate
Sodium citrate may refer to any of the sodium salts of citric acid (though most commonly the third): * Monosodium citrate * Disodium citrate * Trisodium citrate The three forms of salt are collectively known by the E number E331. Applications Food Sodium citrates are used as acidity regulators in food and drinks, and also as emulsifiers for oils. They enable cheeses to melt without becoming greasy and also reduce the acidity of food. They are generally considered safe and are designated GRAS by the FDA. Blood clotting inhibitor Sodium citrate is used to prevent donated blood from clotting in storage, and can also be used as an additive for apheresis to prevent clots forming in the tubes of the machine. By binding with calcium ions in the blood it prevents the process of coagulation. It is also used as an anticoagulant for laboratory testing, in that blood samples are collected into sodium citrate-containing tubes for tests such as the PT (INR), APTT, and fibrinogen levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferric Nitrate
Iron(III) nitrate, or ferric nitrate, is the name used for a series of inorganic compounds with the formula Fe(NO3)3.(H2O)n. Most common is the nonahydrate Fe(NO3)3.(H2O)9. The hydrates are all pale colored, water-soluble paramagnetic salts. Hydrates Iron(III) nitrate is deliquescence, deliquescent, and it is commonly found as the nonahydrate Fe(NO3)3·water of crystallization, 9H2O, which forms colourless to pale violet crystals. This compound is the trinitrate salt of the aquo complex [Fe(H2O)6]3+. Other water of crystallization, hydrates ·''x'', include: * tetrahydrate (''x''=4), more precisely triaqua dinitratoiron(III) nitrate monohydrate, , has complex cations wherein Fe3+ is coordinated with two nitrate anions as bidentate ligands and three of the four water molecules, in a pentagonal bipyramid molecular geometry, pentagonal bipyramid configuration with two water molecules at the poles.H. Schmidt, A. Asztalos, F. Bok and W. Voigt (2012): "New Iron(III) Nitrate Hydrates: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly corrosive base (chemistry), base and alkali that decomposes lipids and proteins at ambient temperatures and at high concentrations may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates . The monohydrate crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide" is often this monohydrate, and published data may refer to it instead of the anhydrous compound. As one of the simplest hydroxides, sodium hydroxide is frequently used alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students. Sodium hydroxide is used in many industries: in the making of wood pulp and paper, tex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
