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The hydrocarboxyl radical , HOCO, is an unstable molecular radical important in combustion . It is formed by the reaction of the hydroxyl radical with carbon monoxide . Hydrocarboxyl then breaks up to form carbon dioxide and atomic hydrogen . Much of the carbon dioxide on Earth and Mars has been produced via the hydroc... | https://en.wikipedia.org/wiki/Hydrocarboxyl |
This page provides supplementary chemical data on Hydrochloric acid .
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet ( MSDS ) for this chemical from a reliable source and follow its directions. | https://en.wikipedia.org/wiki/Hydrochloric_acid_(data_page) |
Hydrochloric acid regeneration or HCl regeneration is a chemical process for the reclamation of bound and unbound HCl from metal chloride solutions such as hydrochloric acid . [ 1 ]
The commercially most relevant field of application for HCl regeneration processes is the recovery of HCl from waste pickle liquors from ... | https://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration |
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid , [ 1 ] while others extend the definition to include substances like aerosols and gels . The ter... | https://en.wikipedia.org/wiki/Hydrocolloid |
A hydrocupration is a chemical reaction whereby a ligated copper hydride species (Cu(I)H), reacts with a carbon-carbon or carbon-oxygen pi-system ; this insertion is typically thought to occur via a four-membered ring transition state , producing a new copper-carbon or copper-oxygen sigma-bond and a stable (generally) ... | https://en.wikipedia.org/wiki/Hydrocupration |
In organic chemistry , hydrocyanation is a process for conversion of alkenes to nitriles . The reaction involves the addition of hydrogen cyanide and requires a catalyst if the substrate alkene is unactivated. This conversion is conducted on an industrial scale for the production of precursors to nylon. Direct hydro... | https://en.wikipedia.org/wiki/Hydrocyanation |
Hydrocyclones are a type of cyclonic separators that separate product phases mainly on basis of differences in gravity with aqueous solutions as the primary feed fluid.
As opposed to dry or dust cyclones, which separate solids from gasses, hydrocyclones separate solids or different phase fluids from the bulk fluid. A ... | https://en.wikipedia.org/wiki/Hydrocyclone |
Hydrodealkylation is a chemical reaction that often involves reacting an aromatic hydrocarbon , such as toluene , in the presence of hydrogen gas to form a simpler aromatic hydrocarbon devoid of functional groups . An example is the conversion of 1,2,4-trimethylbenzene to xylene . [ 1 ] This chemical process usually oc... | https://en.wikipedia.org/wiki/Hydrodealkylation |
Hydrodefluorination ( HDF ) is a type of organic reaction in which in a substrate of a carbon–fluorine bond is replaced by a carbon–hydrogen bond . [ 1 ] [ 2 ] The topic is of some interest to scientific research. In one general strategy for the synthesis of fluorinated compounds with a specific substitution pattern, t... | https://en.wikipedia.org/wiki/Hydrodefluorination |
Hydrodemolition (also known as hydro demolition, hydroblasting, hydro blasting, hydromilling, waterblasting, and waterjetting) is a concrete removal technique which utilizes high-pressure water, often containing an abrasive material, to remove deteriorated and sound concrete as well as asphalt and grout . This process ... | https://en.wikipedia.org/wiki/Hydrodemolition |
Hydrodenitrogenation ( HDN ) is an industrial process for the removal of nitrogen from petroleum . Organonitrogen compounds, even though they occur at low levels, are undesirable because they cause poisoning of downstream catalysts. Furthermore, upon combustion, organonitrogen compounds generate NOx , a pollutant. H... | https://en.wikipedia.org/wiki/Hydrodenitrogenation |
Hydrodeoxygenation (HDO) is a hydrogenolysis process for removing oxygen from oxygen-containing compounds. Typical HDO catalysts commonly are sulfided nickel - molybdenum or cobalt -molybdenum on gamma alumina . An idealized reaction is: [ 1 ]
The first review on HDO was published in 1983. [ 2 ] HDO is of interest i... | https://en.wikipedia.org/wiki/Hydrodeoxygenation |
Hydrodesulfurization ( HDS ), also called hydrotreatment or hydrotreating , is a catalytic chemical process widely used to remove sulfur (S) from natural gas and from refined petroleum products , such as gasoline or petrol , jet fuel , kerosene , diesel fuel , and fuel oils . [ 1 ] [ 2 ] [ 3 ] The purpose of removing t... | https://en.wikipedia.org/wiki/Hydrodesulfurization |
Hydrodimerization is an organic reaction that couples two alkenes to give a symmetrical hydrocarbon. The reaction is often implemented electrochemically ; in that case the reaction is called electrodimerization . The reaction can also be induced with samarium diiodide , a one-electron reductant .
Hydrodimerization is... | https://en.wikipedia.org/wiki/Hydrodimerization |
Hydrodynamic Delivery (HD) is a method of DNA insertion in rodent models. Genes are delivered via injection into the bloodstream of the animal, and are expressed in the liver. This protocol is helpful to determine gene function, regulate gene expression, and develop pharmaceuticals in vivo. [ 1 ]
Hydrodynamic Delivery... | https://en.wikipedia.org/wiki/Hydrodynamic_delivery |
In microbiology , hydrodynamic focusing is a technique used to provide more accurate results when using flow cytometers or Coulter counters for determining the size of bacteria or cells . [ 1 ]
Cells are counted as they are forced to pass through a small channel (often referred to as a flow cell), causing disruptions ... | https://en.wikipedia.org/wiki/Hydrodynamic_focusing |
The hydrodynamic radius of a macromolecule or colloid particle is R h y d {\displaystyle R_{\rm {hyd}}} . The macromolecule or colloid particle is a collection of N {\displaystyle N} subparticles. This is done most commonly for polymers ; the subparticles would then be the units of the polymer. For polymers in solut... | https://en.wikipedia.org/wiki/Hydrodynamic_radius |
In civil engineering (specifically hydraulic engineering ), a hydrodynamic separator ( HDS ), also called a swirl separator, is a stormwater management device that uses cyclonic separation to control water pollution . They are designed as flow-through structures with a settling or separation unit to remove sediment an... | https://en.wikipedia.org/wiki/Hydrodynamic_separator |
In fluid dynamics , hydrodynamic stability is the field which analyses the stability and the onset of instability of fluid flows. The study of hydrodynamic stability aims to find out if a given flow is stable or unstable, and if so, how these instabilities will cause the development of turbulence . [ 1 ] The foundation... | https://en.wikipedia.org/wiki/Hydrodynamic_stability |
In fluid dynamics , helicity is, under appropriate conditions, an invariant of the Euler equations of fluid flow, having a topological interpretation as a measure of linkage and/or knottedness of vortex lines in the flow. This was first proved by Jean-Jacques Moreau in 1961 [ 1 ] and Moffatt derived it in 1969 without ... | https://en.wikipedia.org/wiki/Hydrodynamical_helicity |
In fluid dynamics and elasticity , hydroelasticity or flexible fluid-structure interaction (FSI), is a branch of science which is concerned with the motion of deformable bodies through liquids . The theory of hydroelasticity has been adapted from aeroelasticity , to describe the effect of structural response of the bod... | https://en.wikipedia.org/wiki/Hydroelasticity |
Hydroextractors are machines which are used in the textile processing industry. These are mainly centrifuges . The wet material is placed in the extractor, which has a wall of perforated metal , generally stainless steel . The internal drum rotates at high speed, thus throwing out the water contained in it. The use of ... | https://en.wikipedia.org/wiki/Hydroextractor |
In organic chemistry , hydroformylation , also known as oxo synthesis or oxo process , is an industrial process for the production of aldehydes ( R−CH=O ) from alkenes ( R 2 C=CR 2 ). [ 1 ] [ 2 ] This chemical reaction entails the net addition of a formyl group ( −CHO ) and a hydrogen atom to a carbon-carbon double bon... | https://en.wikipedia.org/wiki/Hydroformylation |
A hydrogel is a biphasic material , a mixture of porous and permeable solids and at least 10% of water or other interstitial fluid . [ 1 ] [ 2 ] The solid phase is a water insoluble three dimensional network of polymers , having absorbed a large amount of water or biological fluids. [ 2 ] [ 3 ] [ 4 ] [ 5 ] Hydrogels ha... | https://en.wikipedia.org/wiki/Hydrogel |
The behavior of quantum dots (QDs) in solution and their interaction with other surfaces is of great importance to biological and industrial applications, such as optical displays, animal tagging , anti-counterfeiting dyes and paints, chemical sensing, and fluorescent tagging . However, unmodified quantum dots tend to ... | https://en.wikipedia.org/wiki/Hydrogel_encapsulation_of_quantum_dots |
Hydrogel fiber is a hydrogel made into a fibrous state, where its width is significantly smaller than its length. The hydrogel's specific surface area at fibrous form is larger than that of the bulk hydrogel, and its mechanical properties also changed accordingly. As a result of these changes, hydrogel fiber has a fast... | https://en.wikipedia.org/wiki/Hydrogel_fiber |
Hydrogen-bond catalysis is a type of organocatalysis that relies on use of hydrogen bonding interactions to accelerate and control organic reactions . In biological systems, hydrogen bonding plays a key role in many enzymatic reactions, both in orienting the substrate molecules and lowering barriers to reaction. [ 1 ] ... | https://en.wikipedia.org/wiki/Hydrogen-bond_catalysis |
A hydrogen-donor solvent is hydrocarbon that transfers hydrogen to hydrogen-poor substrates, such as coal . The hydrogen-poor substrates could be a solute or suspension. The classic hydrogen-donor solvent (or just donor solvent) is tetrahydronaphthalene , [ 1 ] which converts to naphthalene by transfer of two equiva... | https://en.wikipedia.org/wiki/Hydrogen-donor_solvent |
A hydrogen-like atom (or hydrogenic atom ) is any atom or ion with a single valence electron . These atoms are isoelectronic with hydrogen . Examples of hydrogen-like atoms include, but are not limited to, hydrogen itself, all alkali metals such as Rb and Cs , singly ionized alkaline earth metals such as Ca + and Sr + ... | https://en.wikipedia.org/wiki/Hydrogen-like_atom |
Hydrogen-oxidizing bacteria are a group of facultative autotrophs that can use hydrogen as an electron donor . They can be divided into aerobes and anaerobes . The former use hydrogen as an electron donor and oxygen as an acceptor while the latter use sulphate or nitrogen dioxide as electron acceptors . [ 1 ] Species o... | https://en.wikipedia.org/wiki/Hydrogen-oxidizing_bacteria |
Hydrogen-terminated silicon surface is a chemically passivated silicon substrate where the surface Si atoms are bonded to hydrogen. [ 1 ] The hydrogen-terminated surfaces are hydrophobic, luminescent, and amenable to chemical modification. [ 2 ] Hydrogen-terminated silicon is an intermediate in the growth of bulk silic... | https://en.wikipedia.org/wiki/Hydrogen-terminated_silicon_surface |
A hydrogen analyzer is a device used to measure the hydrogen concentration in steels and alloys when the hydrogen concentration is unknown. [ 1 ] It also has industrial applications for corrosion monitoring .
This chemistry -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Hydrogen_analyzer |
The hydrogen anion , H − , is a negative ion of hydrogen, that is, a hydrogen atom that has captured an extra electron. The hydrogen anion is an important constituent of the atmosphere of stars , such as the Sun . In chemistry, this ion is called hydride . The ion has two electrons bound by the electromagnetic force t... | https://en.wikipedia.org/wiki/Hydrogen_anion |
The hydrogen assisted magnesiothermic reduction (" HAMR ") process is a thermochemical process to obtain titanium metal from titanium oxides. [ 1 ] [ 2 ]
A technical challenge in the production of titanium metal is the formation of oxide impurities. The Kroll process , which is widely used commercially, addresses thi... | https://en.wikipedia.org/wiki/Hydrogen_assisted_magnesiothermic_reduction |
Hydrogen chloride Hydrogen fluoride Hydrogen iodide
Hydrogen astatide , also known as astatine hydride , astatane , astatidohydrogen or hydroastatic acid , is a chemical compound with the chemical formula HAt, consisting of an astatine atom covalently bonded to a hydrogen atom. [ 4 ] It thus is a hydrogen halide .
Th... | https://en.wikipedia.org/wiki/Hydrogen_astatide |
In chemistry , hydrogen atom abstraction , or hydrogen atom transfer ( HAT ), refers to a class of chemical reactions where a hydrogen free radical (a neutral hydrogen atom ) is removed from a substrate with another molecule. This process follows the general equation:
HAT reactions are common in various redox reaction... | https://en.wikipedia.org/wiki/Hydrogen_atom_abstraction |
Hydrogen auto-transfer , also known as borrowing hydrogen , is the activation of a chemical reaction by temporary transfer of two hydrogen atoms from the reactant to a catalyst and return of those hydrogen atoms back to a reaction intermediate to form the final product . [ 1 ] [ 2 ] [ 3 ] [ 4 ] Two major classes of bor... | https://en.wikipedia.org/wiki/Hydrogen_auto-transfer |
In chemistry , a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force . It occurs when a hydrogen (H) atom, covalently bonded to a more electronegative donor atom or group ( Dn ), interacts with another electr... | https://en.wikipedia.org/wiki/Hydrogen_bond |
physchem.ox.ac.uk
Hydrogen bromide is the inorganic compound with the formula HBr . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid , which is saturated at 68.85% HBr by weight at room temperature. Aqueous solutions that are 47.6% HBr by mas... | https://en.wikipedia.org/wiki/Hydrogen_bromide |
A hydrogen carrier is an organic macromolecule that transports atoms of hydrogen from one place to another inside a cell or from cell to cell for use in various metabolical processes. [ 1 ] Examples include NADPH , NADH , and FADH . The main role of these is to transport hydrogen atom to electron transport chain which ... | https://en.wikipedia.org/wiki/Hydrogen_carrier |
The compound hydrogen chloride has the chemical formula HCl and as such is a hydrogen halide . At room temperature , it is a colorless gas , which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor . Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydr... | https://en.wikipedia.org/wiki/Hydrogen_chloride |
A hydrogen clathrate is a clathrate containing hydrogen in a water lattice. This substance is interesting due to its possible use to store hydrogen in a hydrogen economy . [ 1 ] [ 2 ] A recent review that accounts the state-of-the-art and future prospects and challenges of hydrogen storage as clathrate hydrates is rep... | https://en.wikipedia.org/wiki/Hydrogen_clathrate |
A hydrogen compressor is a device that increases the pressure of hydrogen by reducing its volume resulting in compressed hydrogen or liquid hydrogen .
Traditionally, applications for hydrogen compressors included Chlorine electrolyser and many chemical applications like the production of hydrogen peroxide (HPPO). The ... | https://en.wikipedia.org/wiki/Hydrogen_compressor |
12.9 (in DMSO) [ 5 ]
Hydrogen cyanide (formerly known as prussic acid ) is a chemical compound with the formula HCN and structural formula H−C≡N . It is a highly toxic and flammable liquid that boils slightly above room temperature , at 25.6 °C (78.1 °F). HCN is produced on an industrial scale and is a highly valued p... | https://en.wikipedia.org/wiki/Hydrogen_cyanide |
The hydrogen cycle consists of hydrogen exchanges between biotic (living) and abiotic (non-living) sources and sinks of hydrogen-containing compounds.
Hydrogen (H) is the most abundant element in the universe. [ 1 ] On Earth, common H-containing inorganic molecules include water (H 2 O), hydrogen gas (H 2 ), hydrogen ... | https://en.wikipedia.org/wiki/Hydrogen_cycle |
Hydrogen damage is the generic name given to a large number of metal degradation processes due to interaction with hydrogen atoms. Molecular gaseous hydrogen does not have the same effect as atoms or ions released into solid solution in the metal.
Carbon steels exposed to hydrogen at high temperatures experience high ... | https://en.wikipedia.org/wiki/Hydrogen_damage |
Hydrogen darkening is a physical degradation of the optical properties of glass . Free hydrogen atoms are able to bind to the SiO 2 silica glass compound forming hydroxyl (OH)—a chemical compound that interferes with the passage of light through the glass .
The problem is particularly relevant to fiber-optic cables —p... | https://en.wikipedia.org/wiki/Hydrogen_darkening |
The hydrogen economy is an umbrella term for the roles hydrogen can play alongside low-carbon electricity to reduce emissions of greenhouse gases . The aim is to reduce emissions where cheaper and more energy-efficient clean solutions are not available. [ 2 ] In this context, hydrogen economy encompasses the production... | https://en.wikipedia.org/wiki/Hydrogen_economy |
Hydrogen embrittlement ( HE ), also known as hydrogen-assisted cracking or hydrogen-induced cracking ( HIC ), is a reduction in the ductility of a metal due to absorbed hydrogen . Hydrogen atoms are small and can permeate solid metals. Once absorbed, hydrogen lowers the stress required for cracks in the metal to initia... | https://en.wikipedia.org/wiki/Hydrogen_embrittlement |
Hydrogen evolution reaction ( HER ) is a chemical reaction that yields H 2 . [ 1 ] The conversion of protons to H 2 requires reducing equivalents and usually a catalyst. In nature, HER is catalyzed by hydrogenase enzymes which rely on iron- and nickel-based catalysts. Commercial electrolyzers typically employ supported... | https://en.wikipedia.org/wiki/Hydrogen_evolution_reaction |
15 (in DMSO) [ 2 ]
Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula H F . It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid . It is the principal industrial source of fluorine , often in the form of hydrofluoric acid, and is an important feeds... | https://en.wikipedia.org/wiki/Hydrogen_fluoride |
A hydrogen fuel cell power plant is a type of fuel cell power plant (or station) which uses a hydrogen fuel cell to generate electricity for the power grid . They are larger in scale than backup generators such as the Bloom Energy Server and can be up to 60% efficient in converting hydrogen to electricity. There is lit... | https://en.wikipedia.org/wiki/Hydrogen_fuel_cell_power_plant |
Hydrogen gas porosity is an aluminium casting defect in the form of a porosity or void in an aluminium casting caused by a high level of hydrogen gas (H 2 ) dissolved in the aluminium at liquid phase . The solubility of hydrogen in solid aluminium is much smaller than in liquid aluminium. As the aluminium freezes, some... | https://en.wikipedia.org/wiki/Hydrogen_gas_porosity |
In chemistry , hydrogen halides ( hydrohalic acids when in the aqueous phase) are diatomic , inorganic compounds that function as Arrhenius acids . The formula is H X where X is one of the halogens : fluorine , chlorine , bromine , iodine , astatine , or tennessine . [ 1 ] All known hydrogen halides are gases at standa... | https://en.wikipedia.org/wiki/Hydrogen_halide |
The hydrogen hypothesis is a model proposed by William F. Martin and Miklós Müller in 1998 that describes a possible way in which the mitochondrion arose as an endosymbiont within a prokaryotic host in the archaea , giving rise to a symbiotic association of two cells from which the first eukaryotic cell could have aris... | https://en.wikipedia.org/wiki/Hydrogen_hypothesis |
A hydrogen infrastructure is the infrastructure of points of hydrogen production , truck and pipeline transport, and hydrogen stations for the distribution and sale of hydrogen fuel , [ 1 ] and thus a crucial prerequisite before a successful commercialization of fuel cell technology. [ 2 ]
Hydrogen stations which are ... | https://en.wikipedia.org/wiki/Hydrogen_infrastructure |
2.8 (in acetonitrile) [ 3 ]
Hydrogen iodide (HI) is a diatomic molecule and hydrogen halide . Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid . Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under standard conditions, whereas the other is a... | https://en.wikipedia.org/wiki/Hydrogen_iodide |
This page provides supplementary chemical data on hydrogen iodide .
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet ( MSDS ) for this chemical from a reliable source such as SIRI , and follow its directions. | https://en.wikipedia.org/wiki/Hydrogen_iodide_(data_page) |
Hydrogen isocyanide is a chemical with the molecular formula HNC. It is a minor tautomer of hydrogen cyanide (HCN). Its importance in the field of astrochemistry is linked to its ubiquity in the interstellar medium .
Both hydrogen isocyanide and azanylidyniummethanide are correct IUPAC names for HNC. There is no prefe... | https://en.wikipedia.org/wiki/Hydrogen_isocyanide |
Hydrogen isotope biogeochemistry (HIBGC) is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes . Hydrogen has two stable isotopes, protium 1 H and deuterium 2 H, which vary in relative abundance on the order of hun... | https://en.wikipedia.org/wiki/Hydrogen_isotope_biogeochemistry |
The hydrogen line , 21 centimeter line , or H I line [ a ] is a spectral line that is created by a change in the energy state of solitary , electrically neutral hydrogen atoms . It is produced by a spin -flip transition, which means the direction of the electron's spin is reversed relative to the spin of the proton. Th... | https://en.wikipedia.org/wiki/Hydrogen_line |
Hydrogen peroxide is a chemical compound with the formula H 2 O 2 . In its pure form, it is a very pale blue [ 5 ] liquid that is slightly more viscous than water . It is used as an oxidizer , bleaching agent, and antiseptic , usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concen... | https://en.wikipedia.org/wiki/Hydrogen_peroxide |
Hydrogen peroxide–urea (also called Hyperol , artizone , urea hydrogen peroxide , and UHP ) is a white crystalline solid chemical compound composed of equimolar amounts of hydrogen peroxide and urea . It contains solid and water -free hydrogen peroxide, which offers a higher stability and better controllability than li... | https://en.wikipedia.org/wiki/Hydrogen_peroxide–urea |
Hydrogen pinch analysis (HPA) is a hydrogen management method that originates from the concept of heat pinch analysis . HPA is a systematic technique for reducing hydrogen consumption and hydrogen generation through integration of hydrogen-using activities or processes in the petrochemical industry , petroleum refineri... | https://en.wikipedia.org/wiki/Hydrogen_pinch |
Hydrogen purification is any technology used to purify hydrogen . The impurities in hydrogen gas depend on the source of the H2, e.g., petroleum, coal, electrolysis, etc. The required purity is determined by the application of the hydrogen gas. For example, ultra-high purified hydrogen is needed for applications like p... | https://en.wikipedia.org/wiki/Hydrogen_purification |
Hydrogen selenide is an inorganic compound with the formula H 2 Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium . H 2 Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compound [ 3 ] with an exposure limit of 0.05 ppm over an 8-hou... | https://en.wikipedia.org/wiki/Hydrogen_selenide |
A hydrogen sensor is a gas detector that detects the presence of hydrogen . They contain micro-fabricated point-contact hydrogen sensors and are used to locate hydrogen leaks. They are considered low-cost, compact, durable, and easy to maintain as compared to conventional gas detecting instruments. [ 1 ]
There are fiv... | https://en.wikipedia.org/wiki/Hydrogen_sensor |
In heterogeneous catalysis , hydrogen molecules can be adsorbed and dissociated by the metal catalyst. Hydrogen spillover is the migration of hydrogen atoms from the metal catalyst onto the nonmetal support or adsorbate. [ 1 ] [ 2 ] Spillover , generally, is the transport of a species adsorbed or formed on a surface on... | https://en.wikipedia.org/wiki/Hydrogen_spillover |
Several methods exist for storing hydrogen . These include mechanical approaches such as using high pressures and low temperatures, or employing chemical compounds that release H 2 upon demand. While large amounts of hydrogen are produced by various industries, it is mostly consumed at the site of production, notably f... | https://en.wikipedia.org/wiki/Hydrogen_storage |
Hydrogen sulfide is a chemical compound with the formula H 2 S . It is a colorless chalcogen-hydride gas , and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. [ 11 ] Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemic... | https://en.wikipedia.org/wiki/Hydrogen_sulfide |
Hydrogen sulfide chemosynthesis is a form of chemosynthesis which uses hydrogen sulfide . [ 1 ] It is common in hydrothermal vent microbial communities [ 2 ] [ 3 ] Due to the lack of light in these environments this is predominant over photosynthesis . [ 4 ]
Giant tube worms use bacteria in their trophosome to fix car... | https://en.wikipedia.org/wiki/Hydrogen_sulfide_chemosynthesis |
A hydrogen tanker or liquid hydrogen tanker is a tank ship designed for transporting liquefied hydrogen .
The World Energy Network research program of the Japanese New Sunshine Project was divided into 3 phases [ 1 ] during the period 1993 to 2002, its goal was to study the distribution of liquid hydrogen with hydroge... | https://en.wikipedia.org/wiki/Hydrogen_tanker |
Hydrogen technologies are technologies that relate to the production and use of hydrogen as a part hydrogen economy . Hydrogen technologies are applicable for many uses.
Some hydrogen technologies are carbon neutral and could have a role in preventing climate change and a possible future hydrogen economy . Hydrogen is... | https://en.wikipedia.org/wiki/Hydrogen_technologies |
Hydrogen telluride is the inorganic compound with the formula H 2 Te . A hydrogen chalcogenide and the simplest hydride of tellurium , it is a colorless gas. Although unstable in ambient air, the gas can exist long enough to be readily detected by the odour of rotting garlic at extremely low concentrations; or by the r... | https://en.wikipedia.org/wiki/Hydrogen_telluride |
Hydrogen transport involves the use of technology to transport hydrogen from the point of generation to the point of use.
Hydrogen can be transported in a variety of forms.
Hydrogen can be transported in gaseous form, typically in a pipeline. Because hydrogen gas is highly reactive, the pipeline or other container mu... | https://en.wikipedia.org/wiki/Hydrogen_transport |
A hydrogen turboexpander-generator or generator-loaded expander for hydrogen gas is an axial flow turbine or radial expander for energy recovery through which a high pressure hydrogen gas is expanded to produce work used to drive an electrical generator . It replaces the control valve or regulator where the pressure dr... | https://en.wikipedia.org/wiki/Hydrogen_turboexpander-generator |
A hydrogenase mimic or bio-mimetic is an enzyme mimic of hydrogenases .
One of the more interesting applications of hydrogenases is to produce hydrogen , due its capacity to catalyze its redox reaction:
In the field of hydrogen production, the incorporation of chemical compounds in electrochemical devices to produce ... | https://en.wikipedia.org/wiki/Hydrogenase_mimic |
Hydrogenated MDI ( H 12 MDI or 4,4′-diisocyanato dicyclohexylmethane ) is an organic compound in the class known as isocyanates . [ 1 ] More specifically, it is an aliphatic diisocyanate. It is a water white liquid at room temperature and is manufactured in relatively small quantities. It is also known as 4,4'-methylen... | https://en.wikipedia.org/wiki/Hydrogenated_MDI |
Hydrogenated starch hydrolysates ( HSHs ), also known as polyglycitol syrup (INS 964), are mixtures of several sugar alcohols (a type of sugar substitute). Hydrogenated starch hydrolysates were developed by the Swedish company Lyckeby Starch in the 1960s. [ 1 ] The HSH family of polyols is an approved food ingredient ... | https://en.wikipedia.org/wiki/Hydrogenated_starch_hydrolysates |
Hydrogenation is a chemical reaction between molecular hydrogen (H 2 ) and another compound or element, usually in the presence of a catalyst such as nickel , palladium or platinum . The process is commonly employed to reduce or saturate organic compounds . Hydrogenation typically constitutes the addition of pairs of h... | https://en.wikipedia.org/wiki/Hydrogenation |
In chemistry, the hydrogenation of carbon–nitrogen double bonds is the addition of the elements of dihydrogen (H 2 ) across a carbon–nitrogen double bond, forming amines or amine derivatives. [ 1 ] Although a variety of general methods have been developed for the enantioselective hydrogenation of ketones, [ 2 ] methods... | https://en.wikipedia.org/wiki/Hydrogenation_of_carbon–nitrogen_double_bonds |
Hydrogenics is a developer and manufacturer of hydrogen generation and fuel cell products based on water electrolysis and proton-exchange membrane (PEM) technology. [ 2 ] [ 3 ] Hydrogenics is divided into two business units: OnSite Generation and Power Systems. Onsite Generation is headquartered in Oevel, Belgium and h... | https://en.wikipedia.org/wiki/Hydrogenics |
Hydrogenography is a combinatorial method based on the observation of optical changes on the metal surface by hydrogen absorption . [ 1 ] The method allows the examination of thousands of combinations of alloy samples in a single batch.
In the 1996 report of the method, thin films were coated with yttrium and lanthanu... | https://en.wikipedia.org/wiki/Hydrogenography |
Hydrogenotrophs are organisms that are able to metabolize molecular hydrogen as a source of energy .
An example of hydrogenotrophy is performed by carbon dioxide -reducing organisms [ 1 ] which use CO 2 and H 2 to produce methane (CH 4 ) by the following reaction:
Other hydrogenotrophic metabolic pathways include ace... | https://en.wikipedia.org/wiki/Hydrogenotroph |
Hydrogen–deuterium exchange (also called H–D or H/D exchange) is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium ... | https://en.wikipedia.org/wiki/Hydrogen–deuterium_exchange |
Hydrogeomorphology has been defined as “an interdisciplinary science that focuses on the interaction and linkage of hydrologic processes with landforms or earth materials and the interaction of geomorphic processes with surface and subsurface water in temporal and spatial dimensions.” [ 1 ] The term 'hydro-geomorpholog... | https://en.wikipedia.org/wiki/Hydrogeomorphology |
Hydrogeophysics is a cross-disciplinary area of research that uses geophysics to determine parameters (characteristics; measurements of limitations or boundaries) and monitor processes for hydrological studies of matters such as water resources, contamination, and ecological studies. [ 1 ] The field uses knowledge and ... | https://en.wikipedia.org/wiki/Hydrogeophysics |
A hydrograph is a graph showing the rate of flow ( discharge ) versus time past a specific point in a river, channel, or conduit carrying flow. The rate of flow is typically expressed in units of cubic meters per second (m³/s) or cubic feet per second (cfs).
Hydrographs often relate changes of precipitation to changes ... | https://en.wikipedia.org/wiki/Hydrograph |
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans , seas , coastal areas , lakes and rivers , as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activ... | https://en.wikipedia.org/wiki/Hydrography |
Hydroids are a life stage for most animals of the class Hydrozoa , small predators related to jellyfish .
Some hydroids such as the freshwater Hydra are solitary, with the polyp attached directly to the substrate . When these produce buds, they become detached and grow on as new individuals.
The majority of hydroids ... | https://en.wikipedia.org/wiki/Hydroid_(zoology) |
Hydroinformatics is a branch of informatics which concentrates on the application of information and communications technologies (ICTs) in addressing the increasingly serious problems of the equitable and efficient use of water for many different purposes. Growing out of the earlier discipline of computational hydrauli... | https://en.wikipedia.org/wiki/Hydroinformatics |
Hydroiodic acid (or hydriodic acid ) is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula H I ( aq ) . It is a strong acid , in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous solutions of hydrogen iodide are usually 48% to 57% HI by mass... | https://en.wikipedia.org/wiki/Hydroiodic_acid |
For the use of hydrologists, ecologists, and water-resource managers in the study of surface water flows in the United States, the United States Geological Survey created a hierarchical system of hydrologic units.
Originally a four-tier system divided into regions , sub-regions, accounting units, and cataloging units,... | https://en.wikipedia.org/wiki/Hydrologic_unit_system_(United_States) |
HEPEX is an international initiative bringing together hydrologists, meteorologists, researchers and endusers to develop advanced probabilistic hydrological forecast techniques for improved flood, drought and water management. HEPEX was launched in 2004 as an independent, cooperative international scientific activity. ... | https://en.wikipedia.org/wiki/Hydrological_Ensemble_Prediction_Experiment |
A hydrological code or hydrologic unit code is a sequence of numbers or letters (a geocode ) that identify a hydrological unit or feature, such as a river , river reach , lake , or area like a drainage basin (also called watershed in North America) or catchment.
One system, developed by Arthur Newell Strahler , known ... | https://en.wikipedia.org/wiki/Hydrological_code |
Hydrological optimization applies mathematical optimization techniques (such as dynamic programming , linear programming , integer programming , or quadratic programming ) to water-related problems. These problems may be for surface water , groundwater , or the combination. The work is interdisciplinary, and may be don... | https://en.wikipedia.org/wiki/Hydrological_optimization |
An hydrological transport model is a mathematical model used to simulate the flow of rivers, streams , groundwater movement or drainage front displacement , and calculate water quality parameters. These models generally came into use in the 1960s and 1970s when demand for numerical forecasting of water quality and drai... | https://en.wikipedia.org/wiki/Hydrological_transport_model |
Hydrology (from Ancient Greek ὕδωρ ( húdōr ) ' water ' and -λογία ( -logía ) ' study of ' ) is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle , water resources , and drainage basin sustainability. A practitioner of hydrology is called a ... | https://en.wikipedia.org/wiki/Hydrology |
Hydrology in Practice is a hydrology textbook by British hydrologist Elizabeth M. Shaw . The book was originally published in 1983 by Van Nostrand Reinhold (UK) Co. Ltd. [ citation needed ] and the most recent fourth edition was published in July 2010 by CRC Press , [ 2 ] a division of Taylor & Francis. The book has be... | https://en.wikipedia.org/wiki/Hydrology_in_Practice |
Fishing Creek is a tributary of the Susquehanna River , in Columbia County, Pennsylvania , in the United States. Hydrology involves the discharge , the pH , the chemical hydrology , the dams , and the water temperature . Data has been gathered from a United States Geological Survey gauging station near Bloomsburg, Penn... | https://en.wikipedia.org/wiki/Hydrology_of_Fishing_Creek_(North_Branch_Susquehanna_River_tributary) |
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