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Oxygen Concentrator
An oxygen concentrator is a device that concentrates the oxygen from a gas supply (typically ambient air) by selectively removing nitrogen to supply an oxygen-enriched product gas stream. They are used industrially, to provide supplemental oxygen at high altitudes, and as medical devices for oxygen therapy. Oxygen concentrators are used widely for oxygen provision in healthcare applications, especially where liquid or pressurized oxygen is too dangerous or inconvenient, such as in homes or portable clinics, and can also provide an economical source of oxygen in industrial processes, where they are also known as oxygen gas generators or Oxygen plant, oxygen generation plants. Two methods in common use are pressure swing adsorption and membrane gas separation. Pressure swing adsorption (PSA) oxygen concentrators use a molecular sieve to adsorb gases and operate on the principle of Pressure swing adsorption#Rapid PSA, rapid pressure swing adsorption of atmospheric nitrogen onto zeol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radon
Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only Rn has a sufficiently long half-life (3.825 days) for it to be released from the soil and rock where it is generated. Radon isotopes are the immediate decay products of radium isotopes. The instability of Rn, its most stable isotope, makes radon one of the rarest elements. Radon will be present on Earth for several billion more years despite its short half-life, because it is constantly being produced as a step in the decay chains of U and Th, both of which are abundant radioactive nuclides with half-lives of at least several billion years. The decay of radon produces many other short-lived nuclides, known as "radon daughters", ending at stable isotopes of lead. Rn occurs in significant quantities as a step in the normal radioactive decay chain of U, also known as the uranium series, which slo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabin Pressurization
Cabin pressurization is a process in which conditioned air is pumped into the aircraft cabin, cabin of an aircraft or spacecraft in order to create a safe and comfortable environment for humans flying at high altitudes. For aircraft, this air is usually Bleed air, bled off from the gas turbine, gas turbine engines at the compressor stage, and for spacecraft, it is carried in high-pressure, often liquid oxygen, cryogenic, tanks. The air is cooled, humidified, and mixed with recirculated air by one or more Environmental control system (aircraft), environmental control systems before it is distributed to the cabin. The first experimental pressurization systems saw use during the 1920s and 1930s. In the 1940s, Boeing 307 Stratoliner, the first commercial aircraft with a pressurized cabin entered service. The practice would become widespread a decade later, particularly with the introduction of the British de Havilland Comet jetliner in 1949. However, South African Airways Flight 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Oxygen Concentrator
A home, or domicile, is a space used as a permanent or semi-permanent residence for one or more human occupants, and sometimes various companion animals. Homes provide sheltered spaces, for instance rooms, where domestic activity can be performed such as sleeping, preparing food, eating and hygiene as well as providing spaces for work and leisure such as remote working, studying and playing. Physical forms of homes can be static such as a house or an apartment, mobile such as a houseboat, trailer or yurt or digital such as virtual space. The aspect of 'home' can be considered across scales; from the micro scale showcasing the most intimate spaces of the individual dwelling and direct surrounding area to the macro scale of the geographic area such as town, village, city, country or planet. The concept of 'home' has been researched and theorized across disciplines – topics ranging from the idea of home, the interior, the psyche, liminal space, contested space to gender an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Hospital
A military hospital is a hospital owned or operated by a military. They are often reserved for the use of military personnel and their dependents, but in some countries are made available to civilians as well. They may or may not be located on a military base; many are not. In the United Kingdom and Germany, British military hospitals have been closed; military personnel are usually treated in a special wing of a designated civilian hospital, in the UK, these are referred to as a Ministry of Defence Hospital Unit. Service personnel injured in combat operations are normally treated at the Royal Centre for Defence Medicine. Examples Asia Azerbaijan Source: * Central Clinical Hospital *Baku Military Garrison Hospital * Military Hospital of Frontiers * Central Customs Hospital * Hospital of the Ministry of Internal Affairs (Azerbaijan), Ministry of Internal Affairs * Central Military Hospital * Military Hospital of the Ministry of National Security of Azerbaijan, Ministry of Na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Facilities
A health facility is, in general, any location where healthcare is provided. Health facilities range from small clinics and doctor's offices to urgent care centers and large hospitals with elaborate emergency rooms and trauma centers. The number and quality of health facilities in a country or region is one common measure of that area's prosperity and quality of life. In many countries, health facilities are regulated to some extent by law; licensing by a regulatory agency is often required before a facility may open for business. Health facilities may be owned and operated by for-profit businesses, non-profit organizations, governments, and, in some cases, individuals, with proportions varying by country. See also the recent review paper, Health facility workload The workload of a health facility is often used to indicate its size. Large health facilities are those with a greater patient load. In Australia the workload of a health facility is used to determine the level of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Diffusivity
Diffusivity, mass diffusivity or diffusion coefficient is usually written as the proportionality constant between the molar flux due to molecular diffusion and the negative value of the gradient in the concentration of the species. More accurately, the diffusion coefficient times the local concentration is the proportionality constant between the negative value of the mole fraction gradient and the molar flux. This distinction is especially significant in gaseous systems with strong temperature gradients. Diffusivity derives its definition from Fick's law and plays a role in numerous other equations of physical chemistry. The diffusivity is generally prescribed for a given pair of species and pairwise for a multi-species system. The higher the diffusivity (of one substance with respect to another), the faster they diffuse into each other. Typically, a compound's diffusion coefficient is ~10,000× as great in air as in water. Carbon dioxide in air has a diffusion coefficient of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Biological membranes include cell membranes (outer coverings of cells or organelles that allow passage of certain constituents); nuclear membranes, which cover a cell nucleus; and tissue membranes, such as mucous membrane, mucosae and serous membrane, serosae. Synthetic membranes are made by humans for use in laboratory, laboratories and industry (such as chemical plants). This concept of a membrane has been known since the eighteenth century but was used little outside of the laboratory until the end of World War II. Drinking water supplies in Europe had been compromised by The War and membrane filters were used to test for water safety. However, due to the lack of reliability, slow operation, reduced selectivity and elevated costs, membran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (structure), perovskite structure, which has a general chemical formula . Many different cations can be embedded in this structure, allowing the development of diverse engineered materials. History The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite's notable crystal structure was first described by Victor Goldschmidt in 1926 in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Occurrence Found in the Earth's Mantle (geology), mantle, perovskite's occurrence at Khibiny Mountains, Khibina Massif is restricted to the silica under-saturat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Dioxide
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a synthetic product. Examples include fused quartz, fumed silica, opal, and aerogels. It is used in structural materials, microelectronics, and as components in the food and pharmaceutical industries. All forms are white or colorless, although impure samples can be colored. Silicon dioxide is a common fundamental constituent of glass. Structure In the majority of silicon dioxides, the silicon atom shows tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flux Distribution Inside The Fiber
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phenomena, flux is a vector quantity, describing the magnitude and direction of the flow of a substance or property. In vector calculus flux is a scalar quantity, defined as the surface integral of the perpendicular component of a vector field over a surface. Terminology The word ''flux'' comes from Latin: ''fluxus'' means "flow", and ''fluere'' is "to flow". As ''fluxion'', this term was introduced into differential calculus by Isaac Newton. The concept of heat flux was a key contribution of Joseph Fourier, in the analysis of heat transfer phenomena. His seminal treatise ''Théorie analytique de la chaleur'' (''The Analytical Theory of Heat''), defines ''fluxion'' as a central quantity and proceeds to derive the now well-known expressions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
