|
Hydrogen Explosion
Hydrogen safety covers the safe production, handling and use of hydrogen, particularly hydrogen gas fuel and liquid hydrogen. Hydrogen possesses the NFPA 704's highest rating of four on the flammability scale because it is flammable when mixed even in small amounts with ordinary air. Ignition can occur at a volumetric ratio of hydrogen to air as low as 4% due to the oxygen in the air and the simplicity and chemical properties of the reaction. However, hydrogen has no rating for innate hazard for reactivity or toxicity. The storage and use of hydrogen poses unique challenges due to its ease of leaking as a gaseous fuel, low-energy ignition, wide range of combustible fuel-air mixtures, buoyancy, and its ability to embrittle metals that must be accounted for to ensure safe operation. Liquid hydrogen poses additional challenges due to its increased density and the extremely low temperatures needed to keep it in liquid form. Moreover, its demand and use in industry—as rocket fuel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hindenburg Disaster
The ''Hindenburg'' disaster was an airship accident that occurred on May 6, 1937, in Manchester Township, New Jersey, Manchester Township, New Jersey, United States. The LZ 129 Hindenburg, LZ 129 ''Hindenburg'' (; Aircraft registration, Registration: D-LZ 129) was a German commercial passenger-carrying rigid airship, the lead ship of the Hindenburg class airship, ''Hindenburg'' class, the longest class of flying machine and the largest airship by envelope volume."Hindenburg Statistics." airships.net, 2009. Retrieved: July 22, 2017. It was designed and built by the Zeppelin Company (Luftschiffbau Zeppelin, ''Luftschiffbau Zeppelin GmbH'') and operated by the German Zeppelin Airline Company (''Deutsche Zeppelin-Reederei''). It was named after ''Generalfeldmarschall'' Paul von Hindenburg, who was President of Germany (1919� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coolant
A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator. While the term "coolant" is commonly used in automotive and HVAC applications, in industrial processing heat-transfer fluid is one technical term more often used in high temperature as well as low-temperature manufacturing applications. The term also covers cutting fluids. Industrial cutting fluid has broadly been classified as water-soluble coolant and neat cutting fluid. Water-soluble coolant is oil in water emulsion. It has varying oil content from nil oil (synthetic coolant). This coolant can either keep its phase and stay liquid or gaseous, or can undergo a phase transition, with the latent heat adding to the cooling efficiency. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonation
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with speeds about 1 km/sec and differ from deflagrations which have subsonic flame speeds about 1 m/sec. Detonation may form from an explosion of fuel-oxidizer mixture. Compared with deflagration, detonation doesn't need to have an external oxidizer. Oxidizers and fuel mix when deflagration occurs. Detonation is more destructive than deflagrations. In detonation, the flame front travels through the air-fuel faster than sound; while in deflagration, the flame front travels through the air-fuel slower than sound. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. TNT, dynamite, and C4 are examples of high power explosives that detonate. The detonation velocity, velocity of detonation in solid an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammability Limit
Flammability limits or explosive limits are the ranges of fuel concentrations in relation to oxygen from the air. Combustion can range in violence from deflagration through detonation. Limits vary with temperature and pressure, but are normally expressed in terms of volume percentage at 25 °C and atmospheric pressure. These limits are relevant both in producing and optimising explosion or combustion, as in an engine, or to preventing it, as in uncontrolled explosions of build-ups of combustible gas or dust. Attaining the best combustible or explosive mixture of a fuel and air (the stoichiometric proportion) is important in internal combustion engines such as gasoline or diesel engines. The standard reference work is still that elaborated by Michael George Zabetakis, a fire safety engineering specialist, using an apparatus developed by the United States Bureau of Mines. Violence of combustion Combustion can vary in degree of violence. A deflagration is a propagation of a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammable
A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame. The degree of flammability in air depends largely upon the volatility of the material this is related to its composition-specific vapour pressure, which is temperature dependent. The quantity of vapour produced can be enhanced by increasing the surface area of the material forming a mist or dust. Take wood as an example. Finely divided wood dust can undergo explosive flames and produce a blast wave. A piece of paper (made from pulp) catches on fire quite easily. A heavy oak desk is much harder to ignite, even though the wood fibre is the same in all three materials. Common sense (and indeed scientific consensus until the mid-1700s) would seem to suggest that mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuterium
Deuterium (hydrogen-2, symbol H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen; the other is protium, or hydrogen-1, H. The deuterium nucleus (deuteron) contains one proton and one neutron, whereas the far more common H has no neutrons. The name ''deuterium'' comes from Greek '' deuteros'', meaning "second". American chemist Harold Urey discovered deuterium in 1931. Urey and others produced samples of heavy water in which the H had been highly concentrated. The discovery of deuterium won Urey a Nobel Prize in 1934. Nearly all deuterium found in nature was synthesized in the Big Bang 13.8 billion years ago, forming the primordial ratio of H to H (~26 deuterium nuclei per 10 hydrogen nuclei). Deuterium is subsequently produced by the slow stellar proton–proton chain, but rapidly destroyed by exothermic fusion reactions. The deuterium–deuterium reaction has the second-lowest energy threshold, and is the most astrophysically acce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressed Natural Gas
Compressed natural gas (CNG) is a fuel gas mainly composed of methane (CH4), compressed to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of , usually in cylindrical or spherical shapes. CNG is used in traditional petrol/internal combustion engine vehicles that have been modified, or in vehicles specifically manufactured for CNG use: either alone (dedicated), with a segregated liquid fuel system to extend range (dual fuel), or in conjunction with another fuel ( bi-fuel). It can be used in place of petrol, diesel fuel, and liquefied petroleum gas (LPG). CNG combustion produces fewer undesirable gases than the aforementioned fuels. In comparison to other fuels, natural gas poses less of a threat in the event of a spill, because it is lighter than air and disperses quickly when released. Biomethane, biogas from anaerobic digestion or landfill, can be used. In response to high fuel prices a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIAA
The American Institute of Aeronautics and Astronautics (AIAA) is a professional society for the field of aerospace engineering. The AIAA is the U.S. representative on the International Astronautical Federation and the International Council of the Aeronautical Sciences. In 2015, it had more than 30,000 members among aerospace professionals worldwide (a majority are American or live in the United States). History The AIAA was founded in 1963 from the merger of two earlier societies: the American Rocket Society (ARS), founded in 1930 as the American Interplanetary Society (AIS), and the Institute of the Aerospace Sciences (IAS), founded in 1932 as the Institute of the Aeronautical Sciences. Paul Johnston was the first executive director of the organization. Jim Harford took his seat after 18 months. The newly-formed structure gathered 47 technical committees and one broad technical publication, the ''AIAA Journal''. The ''AIAA Student Journal'' was also launched in 1963. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethylene Oxide
Ethylene oxide is an organic compound with the chemical formula, formula . It is a cyclic ether and the simplest epoxide: a three-membered ring (chemistry), ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sweet odor. Because it is a strained ring, ethylene oxide easily participates in a number of addition reactions that result in ring-opening. Ethylene oxide is isomeric with acetaldehyde and with vinyl alcohol. Ethylene oxide is industrially produced by oxidation of ethylene in the presence of a silver catalyst. The reactivity that is responsible for many of ethylene oxide's hazards also makes it useful. Although too dangerous for direct household use and generally unfamiliar to consumers, ethylene oxide is used for making many consumer products as well as non-consumer chemicals and intermediates. These products include detergents, thickeners, solvents, plastics, and various organic chemicals such as ethylen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silane
Silane (Silicane) is an inorganic compound with chemical formula . It is a colorless, pyrophoric gas with a sharp, repulsive, pungent smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Silanes with alkyl groups are effective water repellents for mineral surfaces such as concrete and masonry. Silanes with both organic and inorganic attachments are used as coupling agents. They are commonly used to apply coatings to surfaces or as an adhesion promoter. Production Commercial-scale routes Silane can be produced by several routes. Typically, it arises from the reaction of hydrogen chloride with magnesium silicide: : It is also prepared from metallurgical-grade silicon in a two-step process. First, silicon is treated with hydrogen chloride at about 300 °C to produce trichlorosilane, HSiCl3, along with hydrogen gas, according to the chemical equation : The trichlorosilane is then converted to a mixture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylene
Acetylene (Chemical nomenclature, systematic name: ethyne) is a chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.Compressed Gas Association (1995Material Safety and Data Sheet – Acetylene As an alkyne, acetylene is Saturated and unsaturated compounds, unsaturated because its two carbon atoms are Chemical bond, bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°. The triple bond in acetylene results in a high energy content that is released when acetylene is burned. Discovery Acetylene was discovered in 1836 by Edmund Davy, who identified it as a "new carburet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
