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Oxygen Storage
Methods of oxygen storage for subsequent use span many approaches, including high pressures in oxygen tanks, cryogenics, oxygen-rich compounds and reaction mixtures, and chemical compounds that reversibly release oxygen upon heating or pressure change. O2 is the second most important industrial gas. Air Air is the most common source and reservoir of oxygen, containing 20.8% oxygen. This concentration is sufficient for many purposes, such as combustion of many fuels, corrosion of many metals, and breathing of animals. Most humans can function at rest with an oxygen level of 15% at one atmosphere pressure; a fuel such as methane is combustable down to 12% oxygen in nitrogen. A small room of 10 meter3 has 2.08 meter3 (2080 liters) or 2.99 kg of oxygen which would occupy 2.62 liters if it was liquid. High pressure Oxygen tanks containing pressures of up to 200 bar (3000 psi) are used for industrial processes including the manufacturing of steel and monel, welding and cutting, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Tank
An oxygen tank is an oxygen storage vessel, which is either held under pressure in gas cylinders, or as liquid oxygen in a cryogenic storage tank. Uses Oxygen tanks are used to store gas for: * medical breathing at medical facilities and at home * breathing at altitude in aviation, either in a decompression emergency, or constantly (as in unpressurized aircraft) * oxygen first aid kits * oxygen therapy * gas blending, for creating diving breathing mixes such as nitrox, trimix and heliox * open-circuit scuba sets - mainly used for accelerated decompression in technical diving * some types of diving rebreather: oxygen rebreathers and fully closed circuit rebreathers * use in climbing, "Bottled oxygen" refers to oxygen tanks for mountaineering * industrial processes, including the manufacture of steel and monel * oxyacetylene welding equipment, glass lampworking torches, and some gas cutting torches * use as liquid rocket propellants for rocket engines * athletes, specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Perchlorate
Potassium perchlorate is the inorganic salt with the chemical formula K Cl O4. Like other perchlorates, this salt is a strong oxidizer although it usually reacts very slowly with organic substances. This, usually obtained as a colorless, crystalline solid, is a common oxidizer used in fireworks, ammunition percussion caps, explosive primers, and is used variously in propellants, flash compositions, stars, and sparklers. It has been used as a solid rocket propellant, although in that application it has mostly been replaced by the higher performance ammonium perchlorate. Production Potassium perchlorate is prepared industrially by treating an aqueous solution of sodium perchlorate with potassium chloride. This single precipitation reaction exploits the low solubility of KClO4, which is about 1/100 as much as the solubility of NaClO4 (209.6 g/100 mL at 25 °C). It can also be produced by bubbling chlorine gas through a solution of potassium chlorate and potassium hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercalation (chemistry)
In chemistry, intercalation is the reversible inclusion or insertion of a molecule (or ion) into layered materials with layered structures. Examples are found in graphite and transition metal dichalcogenides. : Examples Graphite One famous intercalation host is graphite, which intercalates potassium as a guest. Intercalation expands the van der Waals gap between sheets, which requires energy. Usually this energy is supplied by charge transfer between the guest and the host solid, i.e., redox. Two potassium graphite compounds are KC8 and KC24. Carbon fluorides (e.g., (CF)x and (C4F)) are prepared by reaction of fluorine with graphitic carbon. The color is greyish, white, or yellow. The bond between the carbon and fluorine atoms is covalent, thus fluorine is not intercalated. Such materials have been considered as a cathode in various lithium batteries. Treating graphite with strong acids in the presence of oxidizing agents causes the graphite to oxidise. Graphite bisulfate, 24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite (structure)
A perovskite is any material with a crystal structure following the formula ABX3, which was first discovered as the mineral called perovskite, which consists of calcium titanium oxide (CaTiO3). The mineral was first discovered in the Ural mountains of Russia by Gustav Rose in 1839 and named after Russian mineralogist L. A. Perovski (1792–1856). 'A' and 'B' are two positively charged ions (i.e. cations), often of very different sizes, and X is a negatively charged ion (an anion, frequently oxide) that bonds to both cations. The 'A' atoms are generally larger than the 'B' atoms. The ideal cubic structure has the B cation in 6-fold coordination, surrounded by an octahedron of anions, and the A cation in 12-fold cuboctahedral coordination. Additional perovskite forms may exist where either/both the A and B sites have a configuration of A1x-1A2x and/or B1y-1B2y and the X may deviate from the ideal coordination configuration as ions within the A and B sites undergo changes in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature Swing Absorption
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible to extract energy as heat from a body at that temperature. Temperature is important in all fields of natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Swing Adsorption
Pressure swing adsorption (PSA) is a technique used to separate some gas species from a mixture of gases (typically air) under pressure according to the species' molecular characteristics and affinity for an adsorbent material. It operates at near-ambient temperature and significantly differs from the cryogenic distillation commonly used to separate gases. Selective adsorbent materials (e.g., zeolites, (aka molecular sieves), activated carbon, etc.) are used as trapping material, preferentially adsorbing the target gas species at high pressure. The process then swings to low pressure to desorb the adsorbed gas. Process Pressure swing adsorption process (PSA) is based on the phenomenon that under high pressure, gases tend to be trapped onto solid surfaces, ''i.e.'', to be "adsorbed". The higher the pressure, the more gas is adsorbed. When the pressure is dropped, the gas is released, or desorbed. PSA can be used to separate gases in a mixture because different gases are adsorbed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorption (chemistry)
In chemistry, absorption is a physical or chemical phenomenon or a process in which atoms, molecules or ions enter some bulk phase – liquid or solid material. This is a different process from adsorption, since molecules undergoing absorption are taken up by the volume, not by the surface (as in the case for adsorption). A more common definition is that "Absorption is a chemical or physical phenomenon in which the molecules, atoms and ions of the substance getting absorbed enters into the bulk phase (gas, liquid or solid) of the material in which it is taken up." A more general term is '' sorption'', which covers absorption, adsorption, and ion exchange. Absorption is a condition in which something takes in another substance. In many processes important in technology, the chemical absorption is used in place of the physical process, e.g., absorption of carbon dioxide by sodium hydroxide – such acid-base processes do not follow the Nernst partition law (see: solubility). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozonide
Ozonide is the polyatomic anion . Cyclic organic compounds formed by the addition of ozone () to an alkene are also called ozonides. Ionic ozonides Inorganic ozonides are dark red salts. The anion has the bent shape of the ozone molecule. Inorganic ozonides are formed by burning potassium, rubidium, or caesium in ozone, or by treating the alkali metal hydroxide with ozone; this yields potassium ozonide, rubidium ozonide, and caesium ozonide respectively. They are very sensitive explosives that have to be handled at low temperatures in an atmosphere consisting of an inert gas. Lithium and sodium ozonide are extremely labile and must be prepared by low-temperature ion exchange starting from . Sodium ozonide, , which is prone to decomposition into NaOH and , was previously thought to be impossible to obtain in pure form. However, with the help of cryptands and methylamine, pure sodium ozonide may be obtained as red crystals isostructural to . Ionic ozonides are being investi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-contained Self-rescue Device
Self-sustainability and self-sufficiency are overlapping states of being in which a person or organization needs little or no help from, or interaction with, others. Self-sufficiency entails the self being enough (to fulfill needs), and a self-sustaining entity can maintain self-sufficiency indefinitely. These states represent types of personal or collective autonomy. A self-sufficient economy is one that requires little or no trade with the outside world and is called an autarky. Description Self-sustainability is a type of sustainable living in which nothing is consumed other than what is produced by the self-sufficient individuals. Examples of attempts at self-sufficiency in North America include simple living, food storage, homesteading, off-the-grid, survivalism, DIY ethic, and the back-to-the-land movement. Practices that enable or aid self-sustainability include autonomous building, permaculture, sustainable agriculture, and renewable energy. The term is also applied to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soyuz (spacecraft)
Soyuz () is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau (now Energia). The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet crewed lunar programs. It is launched on a Soyuz rocket from the Baikonur Cosmodrome in Kazakhstan. Between the 2011 retirement of the Space Shuttle and the 2020 demo flight of SpaceX Crew Dragon, the Soyuz served as the only means to ferry crew to or from the International Space Station, for which it remains heavily used. Although China did launch crewed Shenzhou flights during this time, none of them docked with the ISS. History The first Soyuz flight was uncrewed and started on 28 November 1966. The first Soyuz mission with a crew, Soyuz 1, launched on 23 April 1967 but ended with a crash due to a parachute failure, killing cosmonaut Vladimir Komarov. The following flight was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Superoxide
Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a scrubber, dehumidifier, and generator in rebreathers, spacecraft, submarines, and spacesuits. Production and reactions Potassium superoxide is produced by burning molten potassium in an atmosphere of excess oxygen. :K + → The salt consists of and ions, linked by ionic bonding. The O−O distance is 1.28 Å. Reactivity Potassium superoxide is a source of superoxide, which is a reductant and a nucleophile, depending on its reaction partner. Upon contact with water, it undergoes disproportionation to potassium hydroxide, oxygen, and hydrogen peroxide: :2 + → 2 KOH + : + → KOH + + It reacts with carbon dioxide, releasing oxygen: :2 + → K2CO3 + :2 + 2 + H2O → 2 KHCO3 + Potassium superoxide finds only niche uses as a laboratory reag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Perchlorate
Lithium perchlorate is the inorganic compound with the formula LiClO4. This white or colourless crystalline salt is noteworthy for its high solubility in many solvents. It exists both in anhydrous form and as a trihydrate. Applications Inorganic chemistry Lithium perchlorate is used as a source of oxygen in some chemical oxygen generators. It decomposes at about 400 °C, yielding lithium chloride and oxygen: : LiClO4 → LiCl + 2 O2 Over 60% of the mass of the lithium perchlorate is released as oxygen. It has both the highest oxygen to weight and oxygen to volume ratio of all practical perchlorate salts. Organic chemistry LiClO4 is highly soluble in organic solvents, even diethyl ether. Such solutions are employed in Diels–Alder reactions, where it is proposed that the Lewis acidic Li+ binds to Lewis basic sites on the dienophile, thereby accelerating the reaction. Lithium perchlorate is also used as a co-catalyst in the coupling of α,β-unsaturated carbonyls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
