text stringlengths 11 1.65k | source stringlengths 38 44 |
|---|---|
Ligation-independent cloning (LIC) is a form of molecular cloning that is able to be performed without the use of restriction endonucleases or DNA ligase. The technique was developed in the early 1990s as an alternative to restriction enzyme/ligase cloning. This allows genes that have restriction sites to be cloned without worry of chopping up the inserted gene of interest. | https://en.wikipedia.org/wiki?curid=23376161 |
Egil Reksten (3 May 1917 – May 30, 2009) was a Norwegian engineer and resistance member during World War II. He is best known as leader of the illegal radio post Skylark B. Reksten as born in Kristiania (now Oslo), Norway. He was the son of Saron Eriksen Reksten (1875-1955) and his wife Inger Jacobsen (1887-1987). His father is the Rector at Kamper School ("Kampen skole") in the Gamle Oslo district of Oslo. He attended the Norwegian Institute of Technology, and graduated in chemistry in 1941. His professor was Leif Tronstad, a well-known resistance member during the German occupation of Norway since April 1940. In September 1940 the Secret Intelligence Service established two stations for radio communication; the so-called Skylark A in Oslo led by Sverre Midtskau and Skylark B in Trondheim led by Erik Welle-Strand. Skylark B was operated by students at the Institute of Technology, and after technical difficulties in the initial phase, they established regular contact with the intelligence in London in January 1941. Leif Tronstad was also affiliated with the group. When Welle-Strand left the country, Reksten took over as leader of Skylark B. Among others, the group helped spread vital information about German activity at Vemork heavy water plant. The link between heavy water and a German nuclear energy project was established later. After less than a year, however, Gestapo managed to track the Skylark B transmitting activity. Reksten was arrested by the Nazi authorities in September 1941 | https://en.wikipedia.org/wiki?curid=23384664 |
Egil Reksten He was incarcerated at Møllergata 19 from 14 September 1941 to 10 March 1942, then at Akershus Fortress, then at Grini concentration camp from 7 July to 29 July 1943. He was then shipped to Germany with eleven others. Seven of these people died, but after stays in six different Nacht und Nebel camps, Reksten returned to Norway after the war's end. He was decorated for his efforts. In 1947 Reksten started his own engineering company, Argo, together with Erik Welle-Strand and other friends. He spent the rest of his professional career there. He was married, and celebrated his diamond wedding in 2007. He resided in Asker in Akershus, Norway. He died in 2009 and was buried in the churchyard of Haslum Church at Bærum in Akershus . | https://en.wikipedia.org/wiki?curid=23384664 |
Hydroxycholecalciferol may refer to: | https://en.wikipedia.org/wiki?curid=23389556 |
Wetware (biology) The term wetware is used to describe the protocols and molecular devices used in molecular biology and synthetic biology. Where biological components and systems are treated in a similar manner to software, and similar development models and methodologies are applied, the term 'wetware' can be used to imply an approach to their problems as 'bugs' and their beneficial aspects as 'features'. In this manner, genetic code can be subjected to Version Control Systems such as Git, for the development of improvements and new gene edits, therapeutic components and therapies. The National Science Foundation (NSF) funded Wiki project Open Wetware (OWW) provides a resource for reagent, project and laboratory notebook sharing. A somewhat related NSF consortium Synthetic Biology Engineering Research Center (SynBERC) constructs and distributes wetware. | https://en.wikipedia.org/wiki?curid=23402198 |
Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations. It is also used in chemistry to supply energy to reactions over a long period of time. The term "reflux" is very widely used in industries that utilize large-scale distillation columns and fractionators such as petroleum refineries, petrochemical and chemical plants, and natural gas processing plants. In that context, reflux refers to the portion of the overhead liquid product from a distillation column or fractionator that is returned to the upper part of the column as shown in the schematic diagram of a typical industrial distillation column. Inside the column, the downflowing reflux liquid provides cooling and condensation of the upflowing vapors thereby increasing the efficiency of the distillation column. The more reflux provided for a given number of theoretical plates, the better is the column's separation of lower boiling materials from higher boiling materials. Conversely, for a given desired separation, the more reflux is provided, the fewer theoretical plates are required. A mixture of reactants and solvent is placed in a suitable vessel, such as a round bottom flask. This vessel is connected to a water-cooled Liebig or Vigreux condenser, which is typically open to the atmosphere at the top | https://en.wikipedia.org/wiki?curid=23407597 |
Reflux The reaction vessel is heated in order to boil the reaction mixture; vapours produced from the mixture are condensed by the condenser, and return to the vessel through gravity. The purpose is to thermally accelerate the reaction by conducting it at an elevated, controlled temperature (i.e. the solvent's boiling point) and ambient pressure without losing large quantities of the mixture. The diagram shows a typical reflux apparatus. It includes a water bath to indirectly heat the mixture. As many solvents used are flammable, direct heating with a Bunsen burner is not generally suitable, and alternatives such as a water bath, oil bath, sand bath, electric hot plate or heating mantle are employed. The apparatus shown in the diagram represents a batch distillation as opposed to a continuous distillation. The liquid feed mixture to be distilled is placed into the round-bottomed flask along with a few anti-bumping granules, and the fractionating column is fitted into the top. As the mixture is heated and boils, vapor rises up the column. The vapor condenses on the glass platforms (known as plates or trays) inside the column and runs back down into the liquid below, thereby refluxing the upflowing distillate vapor. The hottest tray is at the bottom of the column and the coolest tray is at the top. At steady state conditions, the vapor and liquid on each tray is at equilibrium. Only the most volatile of the vapors stays in gaseous form all the way to the top | https://en.wikipedia.org/wiki?curid=23407597 |
Reflux The vapor at the top of the column then passes into the condenser, where it cools until it condenses into a liquid. The separation can be enhanced with the addition of more trays (to a practical limitation of heat, flow, etc.). The process continues until all the most volatile components in the liquid feed boil out of the mixture. This point can be recognized by the rise in temperature shown on the thermometer. For continuous distillation, the feed mixture enters in the middle of the column. By controlling the temperature of the condenser, often called a dephlegmator, a "reflux still" may be used to ensure that higher boiling point components are returned to the flask while lighter elements are passed out to a secondary condenser. This is useful in producing high quality alcoholic beverages, while ensuring that less desirable components (such as fusel alcohols) are returned to the primary flask. For high quality neutral spirits (such as vodka), or post distillation flavored spirits (gin, absinthe), a process of multiple distillations or charcoal filtering may be applied to obtain a product lacking in any suggestion of its original source material for fermentation. The geometry of the still also plays a role in determining how much reflux occurs. In a "pot still", if the tube leading from the boiler to the condenser, the "lyne arm", is angled upward, more liquid will have a chance to condense and flow back into the boiler leading to increased reflux | https://en.wikipedia.org/wiki?curid=23407597 |
Reflux Typical results can increase production as high as 50% over the basic worm type condenser. The addition of a copper "boiling ball" in the path creates an area where expansion of gasses into the ball causes cooling and subsequent condensation and reflux. In a "column still", the addition of inert materials in the column (e.g., packing) creates surfaces for early condensation and leads to increased reflux. A concentrated solution of ammonium cyanide, refluxed for few days, yields adenine, a component of DNA. This provides a clue about the origin of life on earth. | https://en.wikipedia.org/wiki?curid=23407597 |
Permeability (foundry sand) Permeability is a property of foundry sand with respect to how well the sand can vent, "i.e." how well gases pass through the sand. And in other words, permeability is the property by which we can know the ability of material to transmit fluid/gases. The permeability is commonly tested to see if it is correct for the casting conditions. The grain size, shape and distribution of the foundry sand, the type and quantity of bonding materials, the density to which the sand is rammed, and the percentage of moisture used for tempering the sand are important factors in regulating the degree of permeability. An increase in permeability usually indicates a more open structure in the rammed sand, and if the increase continues, it will lead to penetration-type defects and rough castings. A decrease in permeability indicates tighter packing and could lead to blows and pinholes. The absolute permeability number, which has no units, is determined by the rate of flow of air, under standard pressure, through a rammed cylindrical specimen. DIN standards define the specimen dimensions to be 50 mm in diameter and 50 mm tall, while the American Foundry Society defines it to be two inches in diameter and two inches tall. rammed cylindrical specimen. formula is PN = (VxH)/PxAxT where American Foundry Society has also released a chart where back pressure (P) from a rammed specimen placed on a permeability meter is correlated with a Permeability number | https://en.wikipedia.org/wiki?curid=23409018 |
Permeability (foundry sand) The Permeability number so measured is used in foundries for recording permeability value. | https://en.wikipedia.org/wiki?curid=23409018 |
Clapeyron's theorem (elasticity) In the linear theory of elasticity Clapeyron's theorem states that the potential energy of deformation of a body, which is in equilibrium under a given load, is equal to half the work done by the external forces computed assuming these forces had remained constant from the initial state to the final state. It is named after the French scientist Benoît Clapeyron. For example consider a linear spring with initial length "L" and gradually pull on the spring until it reaches equilibrium at a length "L" when the pulling force is "F". By the theorem, the potential energy of deformation in the spring is given by: The actual force increased from 0 to "F" during the deformation; the work done can be computed by integration in distance. Clapeyron's equation, which uses the final force only, may be puzzling at first, but is nevertheless true because it includes a corrective factor of one half. Another theorem, the theorem of three moments used in bridge engineering is also sometimes called Clapeyron's theorem. | https://en.wikipedia.org/wiki?curid=23409462 |
Theorem of three moments In civil engineering and structural analysis Clapeyron's theorem of three moments is a relationship among the bending moments at three consecutive supports of a horizontal beam. Let "A,B,C" be the three consecutive points of support, and denote by- l the length of "AB" and formula_1 the length of "BC", by "w" and formula_2 the weight per unit of length in these segments. Then the bending moments formula_3 at the three points are related by: This equation can also be written as where "a" is the area on the bending moment diagram due to vertical loads on AB, "a" is the area due to loads on BC, "x" is the distance from A to the centroid of the bending moment diagram of beam AB, "x" is the distance from C to the centroid of the area of the bending moment diagram of beam BC. The second equation is more general as it does not require that the weight of each segment be distributed uniformly. Mohr's theorem can be used to derive the three moment theorem (TMT). The change in slope of a deflection curve between two points of a beam is equal to the area of the M/EI diagram between those two points.(Figure 02) Consider two points k1 and k2 on a beam. The deflection of k1 and k2 relative to the point of intersection between tangent at k1 and k2 and vertical through k1 is equal to the moment of M/EI diagram between k1 and k2 about k1 | https://en.wikipedia.org/wiki?curid=23409732 |
Theorem of three moments (Figure 03) The three moment equation expresses the relation between bending moments at three successive supports of a continuous beam, subject to a loading on a two adjacent span with or without settlement of the supports. According to the Figure 04, PB'Q is a tangent drawn at B' for final Elastic Curve A'B'C' of the beam ABC. RB'S is a horizontal line drawn through B'. Consider, Triangles RB'P and QB'S. From (1), (2), and (3), Draw the M/EI diagram to find the PA' and QC'. From Mohr's Second Theorem PA' = First moment of area of M/EI diagram between A and B about A. QC' = First moment of area of M/EI diagram between B and C about C. Substitute in PA' and QC' on equation (a), the Three Moment Theorem (TMT) can be obtained. | https://en.wikipedia.org/wiki?curid=23409732 |
List of drugs banned by WADA This list of drugs banned by WADA is determined by the World Anti-Doping Agency, established in 1999 to deal with the increasing problem of doping in the sports world. The banned substances and techniques fall into the following categories: androgens, blood doping, peptide hormones, stimulants, diuretics, narcotics, and cannabinoids. Blood doping is the injection of red blood cells, related blood products that contain red blood cells, or artificial oxygen containers. This is done by extracting and storing one's own blood prior to an athletic competition, well in advance of the competition so that the body can replenish its natural levels of red blood cells, and subsequently injecting the stored blood immediately before competition. The resulting unnatural level of red blood cells improves oxygen transport and athletic endurance; thus, it is prohibited in most events. It is often used in extreme sports like cycling, snowboarding, and skiing where endurance is highly valued. The most famous example of this type of doping is Lance Armstrong's performance in the Tour de France. Banned androgenic agents are either anabolic steroids, which increase testosterone and epitestosterone, thereby improving muscle strength and endurance, or beta-2 agonists (see adrenergic beta-agonist). Andro, DHEA, stanozolol, testosterone, and nandrolone, or derivates (see below) are banned anabolic steroids. Beta-2 agonists can act as bronchodilators and increase heart rates, in addition to their mild androgenic effects | https://en.wikipedia.org/wiki?curid=23416255 |
List of drugs banned by WADA Other banned androgenic agents include bambuterol, clenbuterol, salbutamol, tibolone, zeranol, zilpaterol, and selective androgen receptor modulators. While a few of the banned drugs are endogenous, that is they are normally produced in the human body, most of the banned drug are exogenous drugs chemically produced. These types of drugs were used extensively in Major League Baseball in the 1990s and early 2000s. This is the complete list of exogenous (non-natural) androgenic agents banned as of January 1, 2012: Drugs with similar structures and biological activity are also banned because new designer drugs of this sort are always being developed in order to beat the drug tests. The following substances, ordinarily produced naturally in the body, are prohibited when administered from outside the body. Metabolites and isomers of endogenous anabolic androgenic steroids, including: Certain peptide hormones increase bulk, strength, and oxygen-carrying red blood cells. Erythropoiesis-stimulating agents such as erythropoietin (EPO), darbepoetin (dEPO), hypoxia-inducible factor (HIF) stabilizers, methoxy polyethylene glycol-epoetin beta (CERA) and peginesatide (Hematide); growth hormone (hGH), insulin-like growth factors (IGF-1, etc | https://en.wikipedia.org/wiki?curid=23416255 |
List of drugs banned by WADA ), fibroblast growth factors (FGFs), hepatocyte growth factors (HGF), mechano growth factors (MGFs), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), chorionic gonadotropin (banned in men only), somatotrophin (growth hormone), insulins and corticotrophins, corticosteroid mimics, and their releasing factor, are banned. Also banned are any other growth factor affecting muscle, tendon or ligament protein synthesis/degradation, vascularization, energy utilization, regenerative capacity or fiber type switching; and other substances with similar chemical structure or similar biological effects. All beta-2 agonists and their - and -isomers, are banned. However, formoterol, salbutamol, salmeterol, and terbutaline may be used with a "therapeutic use exemption", only in the inhaled form. Hormone levels of a particular hormone, like testosterone, can be changed not only by administering it, but also by altering related hormones. For example, the estrogens estrone and estradiol are biosynthetically produced by the enzyme aromatase, respectively, from androstenedione and testosterone, which are both produced from 17α-hydroxyprogesterone. Thus, when the body senses low levels of estrogen, the precursor compounds 17α-hydroxyprogesterone, androstenedione, and testosterone are up-regulated. Likewise, interfering with a hormone's receptor leads to similar effects | https://en.wikipedia.org/wiki?curid=23416255 |
List of drugs banned by WADA Because of these natural hormone-hormone interdependent biosynthetic pathways and hormone-receptor interactions, all aromatase inhibitors, including anastrozole, letrozole, aminoglutethimide, exemestane, formestane, and testolactone are banned. Selective estrogen receptor modulators, including raloxifene, tamoxifen and toremifene are banned. Clomiphene, cyclofenil, fulvestrant, and all other anti-estrogenic substances are banned. Myostatin inhibitors are banned. Metabolic modulators including peroxisome proliferator-activated receptor delta (PPARδ) agonists (e.g., GW 1516), PPARδ-AMP-activated protein kinase (AMPK) axis agonists (e.g. AICAR) are also banned. Meldonium was banned on 1 January 2016, which was often used during the Russian doping scandal. Stimulants directly affect the central nervous system, increasing blood flow and heart rate. These drugs primarily help athletes in complex team sports like basketball and association football as well as choreographed sports like figure skating and artistic gymnastics. Stimulants that are banned include amphetamines, beta-2 agonists, ephedrine, pseudoephedrine, fencamfamine, cocaine, methamphetamines, mesocarb, and other substances with similar chemical structures and biological effects, including the following: Diuretics, which increase the production of urine, and masking agents, chemical compounds which interfere with drug tests, are banned for two reasons | https://en.wikipedia.org/wiki?curid=23416255 |
List of drugs banned by WADA First, by decreasing water retention and thus decreasing an athlete's weight, an important consideration in many speed sports (e.g. track and field, speed skating), they increase the speed of an athlete. Secondly, increased urine production depletes the concentration of both the banned drugs and their metabolites, making their detection more difficult. Masking agents, on the other hand, work by making drug tests ineffective, leading to false-negative results. Desmopressin, plasma expanders (such as glycerol; intravenous administration of albumin, dextran, hydroxyethyl starch and mannitol), probenecid, and other substances with similar biological effects are also banned. Local application of felypressin in dental anesthesia is not prohibited. The following diuretics, and chemicals with similar structure or biological activity are banned: Narcotic analgesics decrease the painful sensations of serious injuries, potentially allowing athletes to continue training for competition after an injury. While some painkillers are allowed, including codeine, the following are banned: The cannabis products marijuana and hashish are also banned in competition due to their cannabinoid content. Glucocorticoids are a class of corticosteroids that affect the metabolism of carbohydrates, fat, and proteins, and regulate glycogen and blood pressure levels. They possess pronounced anti-inflammatory activity and cause alteration of connective tissue in response to injuries | https://en.wikipedia.org/wiki?curid=23416255 |
List of drugs banned by WADA The anti-inflammatory and connective tissue effects of glucocorticoids might mask injuries, leading to more serious injuries to athletes. Because of this and metabolic regulation effects, the administration of any glucorticoid orally, rectally, intraveniously, or intramuscularly is prohibited and requires a therapeutic use exemption. Topical uses of glucocorticoids does not require an exemption. Beta blockers are prohibited during competition in a number of sports; out of competition, they are prohibited only in archery and shooting. The prohibited beta blockers include: Therapeutic use exemptions (TUEs) is a term used by WADA and the United States Anti-Doping Agency to denote banned substances that athletes may be "required to take to treat an illness or condition". These exemptions are regulated by the International Standard for Therapeutic Use Exemptions (ISTUE). The detection of such substances in samples is labelled by WADA as an "adverse analytical finding" (AAF), which is distinct from "anti-doping rules violations" (ADRV). | https://en.wikipedia.org/wiki?curid=23416255 |
Thin layer extraction is a time-periodic reactive liquid extraction process that provides excellent mass transfer while maintaining phase separation. It is performed via a periodic batch production process that controls the time of each chemical reaction. A small amount of a liquid organic extract is spread, as a thin layer, onto a matrix made of a thin microporous material whose surfaces are freely accessible from and to the outside. The extract is held by capillary forces or other forces. This layer is alternately and repeatedly brought into brief contact with thin layers of the donor and the strip aqueous liquid. In the extraction step, selected species that are present in the donor solution are transported from the donor aqueous solution to the organic phase where a reaction ensues. In the stripping step the reaction reverses and the extracted species are stripped into the strip aqueous solution. Thus, two alternate product batches are generated: a raffinate and a strip product. As each of the species to be separated associates differently with the host, the composition of the raffinate and strip product is differentiated. With a typical liquid mass diffusivity in the order of 10 m/s, the characteristic time for diffusion through a 20 micron thick liquid layer is 0.4 s. Therefore, the thinness of both phases (organic and aqueous) causes a relatively "immediate" mass transfer of guest species from one phase to the other, which means that this process has a low mass transfer resistance | https://en.wikipedia.org/wiki?curid=23417063 |
Thin layer extraction The low mass transfer resistance permits the uncoupling of effects attributed to mass transfer from the effects attributed to the reaction rates; it also allows relatively frequent cycling that helps mitigate the limited capacity that is due to the small batches of aqueous feed processed within each cycle. A secondary characteristic of thin layer extraction arises from the batch periodic mode of operation. It permits precise control in time and space over small processed elements in the course of the process, a degree of control that is not possible in any other liquid-liquid extraction method. This control is instrumental in enabling the exploitation of differences in reaction rates of the different species (see Thermodynamic versus kinetic reaction control) and the “harvesting” of separated species early on the reaction trajectories where the relative differences in concentration are largest. This forms the basis for kinetic, reactive, thin layer extraction. The extractant, including the host, must be substantially insoluble in the processed aqueous solutions to avoid being washed away. However, the difference in density between the immiscible phases, which plays an important role in conventional liquid-liquid extraction, is irrelevant in thin layer extraction | https://en.wikipedia.org/wiki?curid=23417063 |
Thin layer extraction When the separation of two closely related compounds by liquid-liquid extraction is necessary, conventional wisdom indicates that a selective extractant must be found that will discern between the two by associating each to different equilibrium compositions. is recommended for the separation of high-value products that are produced in moderate volumes (for example the separation of chiral molecules). is used in specialized equipment operated as robots consisting of: A thin layer extraction cell consists of a section of the matrix that takes turns at being alternately exposed to the donor and then the strip solutions. Each cell accepts two alternating aqueous feed batches and generates two corresponding alternating batches of the products. In multistage operation, a train of cells is operated synchronously with the products from one cell directed as feeds to a next upstream or downstream cell. The multistage thin layer extraction equipment is linearly scalable, permitting results obtained on table-top laboratory devices to be directly scaled up to full-scale production plants. | https://en.wikipedia.org/wiki?curid=23417063 |
Benzotriyne or cyclo[6]carbon is a hypothetical chemical compound, an allotrope of carbon with molecular formula C. The molecule is a ring of six carbon atoms, connected by alternating triple and single bonds. It is, therefore, a potential member of the cyclo["n"]carbon family. There have been a few attempts to synthesize benzotriyne, e.g. by pyrolysis of mellitic anhydride, but without success . Recent investigations have concluded that benzotriyne is unlikely to exist due to the large angle strain. A likely alternative isomer would be a cyclic cumulene called cyclohexahexaene, which should itself be a metastable species. Name "cracatene" was suggested for this compound (after Karel Čapek's Krakatit, a hypothetical explosive), which however has been considered a scientific blunder by some. | https://en.wikipedia.org/wiki?curid=23421676 |
Cyclocarbon A cyclo["n"]carbon is a chemical compound consisting solely of a number "n" of carbon atoms covalently linked in a ring. Since the compounds are composed only of carbon atoms, they are allotropes of carbon. Possible bonding patterns include all double bonds (a cyclic cumulene) or alternating single bonds and triple bonds (a cyclic polyyne). As of 2020, the only cyclocarbon that has been synthesized is cyclo[18]carbon. The (hypothetical) six-carbon member of this family (C) is also called benzotriyne. The smallest cyclo["n"]carbon predicted to be thermodynamically stable is C, with a computed strain energy of 72 kilocalories per mole. An IBM/Oxford team claimed to synthesize its molecules in solid state in 2019: According to these IBM researchers, the synthesized cyclocarbon has alternating triple and single bonds, rather than being made of entirely of double bonds. This supposedly makes this molecule a semiconductor. Kaiser, K. et al. Science https://doi.org/10.1126/science.aay1914 (2019). | https://en.wikipedia.org/wiki?curid=23421894 |
Fast Sulphon Black F is a complexometric indicator used with EDTA, almost exclusively used in copper complexation determination. Fast Sulphon Black is purple when complexed with copper, and turns green when titrated against EDTA, as the EDTA displaces it, being the better complexing agent due to the chelate effect. | https://en.wikipedia.org/wiki?curid=23422002 |
Latimer diagram A of a chemical element is a summary of the standard electrode potential data of that element. This type of diagram is named after Wendell Mitchell Latimer, an American chemist. In a Latimer diagram, the most highly oxidized form of the element is on the left, with successively lower oxidation states to the right. The species are connected by arrows, and the numerical value of the standard potential (in volts) for the reduction is written at each arrow. For example, for oxygen, the species would be in the order O (0), HO (–1), HO (-2)): The arrow between Oand HO has a value +0.68 V over it, it indicates that the standard electrode potential for the reaction: is 0.68 volts. Latimer diagrams can be used in the construction of Frost diagrams, as a concise summary of the standard electrode potentials relative to the element. Since ΔG = -nFE, the electrode potential is a representation of the Gibbs energy change for the given reduction. The sum of the Gibbs energy changes for subsequent reductions (e.g. from O to HO, then from HO to HO) is the same as the Gibbs energy change for the overall reduction (i.e. from O to HO), in accordance with Hess's law. This can be used to find the electrode potential for non-adjacent steps, which gives all the information necessary for the Frost diagram | https://en.wikipedia.org/wiki?curid=23422531 |
Latimer diagram A simple examination of a can also indicate if a species will disproportionate in solution under the conditions for which the electrode potentials are given: if the potential to the right of the species is higher than the potential on the left, it will disproportionate. | https://en.wikipedia.org/wiki?curid=23422531 |
Ocean chemistry Ocean chemistry, also known as marine chemistry, is influenced by plate tectonics and seafloor spreading, turbidity currents, sediments, pH levels, atmospheric constituents, metamorphic activity, and ecology. The field of chemical oceanography studies the chemistry of marine environments including the influences of different variables. Colored dissolved organic matter (CDOM) is estimated to range 20-70% of carbon content of the oceans, being higher near river outlets and lower in the open ocean. Marine life is largely similar in biochemistry to terrestrial organisms, except that they inhabit a saline environment. One consequence of their adaptation is that marine organisms are the most prolific source of halogenated organic compounds. The ocean provides special marine environments inhabited by extremophiles that thrive under unusual conditions of temperature, pressure, and darkness. Such environments include hydrothermal vents and black smokers and cold seeps on the ocean floor, with entire ecosystems of organisms that have a symbiotic relationship with bacteria and hydrocarbon compounds that provided energy through a process called chemosynthesis. Seafloor spreading on mid-ocean ridges is a global scale ion-exchange system. Hydrothermal vents at spreading centers introduce various amounts of iron, sulfur, manganese, silicon and other elements into the ocean, some of which are recycled into the ocean crust | https://en.wikipedia.org/wiki?curid=23423919 |
Ocean chemistry Helium-3, an isotope that accompanies volcanism from the mantle, is emitted by hydrothermal vents and can be detected in plumes within the ocean. Spreading rates on mid-ocean ridges vary between 10 and 200 mm/yr. Rapid spreading rates cause increased basalt reactions with seawater. The magnesium/calcium ratio will be lower because more magnesium ions are being removed from seawater and consumed by the rock, and more calcium ions are being removed from the rock and released to seawater. Hydrothermal activity at ridge crest is efficient in removing magnesium. A lower Mg/Ca ratio favors the precipitation of low-Mg calcite polymorphs of calcium carbonate (calcite seas). Slow spreading at mid-ocean ridges has the opposite effect and will result in a higher Mg/Ca ratio favoring the precipitation of aragonite and high-Mg calcite polymorphs of calcium carbonate (aragonite seas). Experiments show that most modern high-Mg calcite organisms would have been low-Mg calcite in past calcite seas, meaning that the Mg/Ca ratio in an organism's skeleton varies with the Mg/Ca ratio of the seawater in which it was grown. The mineralogy of reef-building and sediment-producing organisms is thus regulated by chemical reactions occurring along the mid-ocean ridge, the rate of which is controlled by the rate of sea-floor spreading. Increased carbon dioxide levels, resulting from anthropogenic factors or otherwise, have the potential to impact ocean chemistry | https://en.wikipedia.org/wiki?curid=23423919 |
Ocean chemistry Global warming and changes in salinity have significant implications for ecology of marine environments. One proposal suggests dumping massive amounts of lime, a base, to reverse the acidification and "increase the sea's ability to absorb carbon dioxide from the atmosphere". A planetary scientist using data from the Cassini spacecraft has been researching the marine chemistry of Saturn's moon Enceladus using geochemical models to look at changes through time. The presence of salts may indicate a liquid ocean within the moon, raising the possibility of the existence of life, "or at least for the chemical precursors for organic life". | https://en.wikipedia.org/wiki?curid=23423919 |
C20H30O2 The molecular formula CHO (molar mass : 302.45 g/mol, exact mass : 302.22458) may refer to: | https://en.wikipedia.org/wiki?curid=23428795 |
C12H10 The molecular formula CH may refer to: | https://en.wikipedia.org/wiki?curid=23428800 |
C12H8 The molecular formula CH (molar mass: 152.19 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23428824 |
C19H22N2OS The molecular formula CHNOS may refer to: | https://en.wikipedia.org/wiki?curid=23428866 |
C13H9N The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23429132 |
C17H19N3 The molecular formula CHN (molar mass : 265.35 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23429139 |
C3H3N CHN may refer to: Compounds sharing the molecular formula: | https://en.wikipedia.org/wiki?curid=23429221 |
Acta Chimica Slovenica is a quarterly scientific journal of chemistry. It comprises two parts: The first part contains peer-reviewed scientific and expert articles from the various fields of chemistry, written in English and accompanied by abstracts in Slovene. The second part, written in Slovene, contains societal news: lists of newly conferred academic degrees, reports on the work of the sections of the Slovenian Chemical Society, expert articles and book reviews, and news on conferences and other meetings. The journal and the articles published since 1998 are also available online. The journal was established in 1954 as "Vestnik Slovenskega kemijskega društva" and obtained its current name in 1993. | https://en.wikipedia.org/wiki?curid=23429501 |
C10H13N5O4 The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23431640 |
C9H9NO3 The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23431744 |
C21H28O5 The molecular formula CHO (molar mass: 360.44 g/mol, exact mass: 360.193674) may refer to: | https://en.wikipedia.org/wiki?curid=23431804 |
C25H54ClN The molecular formula CHClN (molar mass: 404.16 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23431822 |
C14H8O4 The molecular formula CHO (molar mass : 240.21 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23431831 |
C7H7NO2 The molecular formula CHNO (molar mass: 137.14 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23431923 |
C6H15N3 The molecular formula CHN (molar mass: 129.2 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23431939 |
C7H7NO3 The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23431957 |
HARMST is an acronym for "h"igh "a"spect "r"atio "m"icrostructure "t"echnology, which describes fabrication technologies, used to create high-aspect-ratio microstructures with heights between tens of micrometers up to a centimeter, and aspect ratios greater than 10:1. Examples include the LIGA fabrication process, advanced silicon etch, and deep reactive ion etching. | https://en.wikipedia.org/wiki?curid=23431978 |
C11H18N2O3 The molecular formula CHNO (molar mass: 226.27 g/mol) may be referred as: | https://en.wikipedia.org/wiki?curid=23432094 |
David Adler Lectureship Award in the Field of Materials Physics The is a prize that has been awarded annually by the American Physical Society since 1988. The recipient is chosen for "an outstanding contributor to the field of materials physics, who is noted for the quality of his/her research, review articles and lecturing." The prize is named after physicist David Adler with contributions to the endowment by friends of David Adler and Energy Conversion Devices, Inc. The prize includes a $5,000 honorarium. Source: American Physical Society | https://en.wikipedia.org/wiki?curid=23432134 |
C9H13N The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23432155 |
C16H19N3O5S The molecular formula CHNOS (molar mass: 365.4 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23432170 |
C10H12O The molecular formula CHO (molar mass : 148.2 g/mol) can refer to: | https://en.wikipedia.org/wiki?curid=23432215 |
C8H7ClO2 The molecular formula CHClO (molar mass: 170.59 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23432291 |
C22H12 The molecular formula CH may refer to: | https://en.wikipedia.org/wiki?curid=23432304 |
C14H8O2 The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23432358 |
C14H10O The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23432375 |
C11H12N2O The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23432389 |
C6H14N4O2 The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23432471 |
C4H8N2O3 The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23432570 |
C14H18N2O5 The molecular formula CHNO (molar mass: 294.303 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23432620 |
C20H22O3 The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23433004 |
C12H10N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23433713 |
C14H18N4O3 The molecular formula CHNO (molar mass: 290.318 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23433902 |
C7H6O The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23433925 |
C7H7NO The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23433973 |
C12H12N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23434098 |
C14H10O2 The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23434128 |
C14H12O3 The molecular formula CHO (molar mass : 228.25 g/mol, exact mass : 228.078644) may refer to: | https://en.wikipedia.org/wiki?curid=23434150 |
C7H6N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23434185 |
C7H5NO The molecular formula CHNO may refer to: | https://en.wikipedia.org/wiki?curid=23434228 |
C12H8N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23434278 |
C20H12 The molecular formula CH may refer to: | https://en.wikipedia.org/wiki?curid=23434740 |
C9H11NO2 The molecular formula CHNO (molar mass: 165.18 g/mol, exact mass: 165.078979) may refer to: | https://en.wikipedia.org/wiki?curid=23434758 |
C7H6O2 The molecular formula CHO (molar mass: 122.12 g/mol, exact mass: 122.036779 u) may refer to: | https://en.wikipedia.org/wiki?curid=23434812 |
C14H12O2 The molecular formula CHO (molar mass : 212.24 g/mol, exact mass: 212.08373 u) may refer to: | https://en.wikipedia.org/wiki?curid=23434845 |
C7H5NS The molecular formula CHNS may refer to: | https://en.wikipedia.org/wiki?curid=23434867 |
C8H6S The molecular formula CHS may refer to: | https://en.wikipedia.org/wiki?curid=23434890 |
C7H5ClO The molecular formula CHClO may refer to: | https://en.wikipedia.org/wiki?curid=23434974 |
C7H8O The molecular formula CHO (molar mass: 108.13 g/mol, exact mass: 108.057515 u) may refer to: Also possible hetero aromatic compounds containing oxygen(5 membered rings) | https://en.wikipedia.org/wiki?curid=23434999 |
C7H9N The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23435056 |
C10H10O CHO may refer to: Compounds sharing the molecular formula: | https://en.wikipedia.org/wiki?curid=23435174 |
The Journal of Physical Chemistry Letters is a peer-reviewed scientific journal published by the American Chemical Society, designed to complement "The Journal of Physical Chemistry A". The editor-in-chief is George C. Schatz at Northwestern University and the deputy editor Gregory D. Scholes at Princeton University. The "Journal of Physical Chemistry Letters" covers research on all aspects of physical chemistry. According to the "Journal Citation Reports", the journal had an impact factor of 7.329 for 2018. | https://en.wikipedia.org/wiki?curid=23435184 |
C30H50O2 The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23435316 |
C10H16N2O3S The molecular formula CHNOS (molar mass : 244.31 g/mol) may refer to : | https://en.wikipedia.org/wiki?curid=23435343 |
C10H8N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23435460 |
C14H18N2 The molecular formula CHN may refer to: | https://en.wikipedia.org/wiki?curid=23435485 |
C2H4Cl2O CHClO may refer to: Compounds sharing the molecular formula: | https://en.wikipedia.org/wiki?curid=23435534 |
C15H16O2 The molecular formula CHO (molar mass: 228.286 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23435618 |
C10H18O The molecular formula CHO (molar mass : 154.25 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23435665 |
M17 gas mask The M17 Protective Mask is a series of gas masks that were designed and produced in 1959 (as a replacement of the M-9 gas mask) to provide protection from all types of known chemical and biological agents present. The M-17 was issued to troops in the Vietnam war, and was standard issue for the U.S. Military until it was replaced by the M40 Field Protective Mask for the U.S. Army and USMC in the mid 1990s while the U.S. Air Force and U.S. Navy replaced it for the MCU-2/P Gas Mask in the mid-1980s. The mask has different components including a filter, a face piece and outserts. Filter elements in the face piece prevent harmful agents from entering the mask. The M17 series includes three types of masks, the M17, M17A1 and M17A2. An experimental transparent-silicone model called the XM27 was designed in late 1966, but was turned down in favor of the XM28E4. Many countries have copied the M17 design. Notable copies include the Bulgarian PDE-1, Japanese Type-3, the Polish Mp-4 and the Czech OM10 or M10M. These protective masks have inbuilt voice emitter systems that facilitate communication, a tube for drinking water from the M1 canteen cap (A1 & A2), and a pair of outserts to protect eye lenses and an air pathway that reduced fogging. Three varieties of outserts were available for the mask; clear for general operations, gray tinted for bright environments, and green tinted to protect the wearer from battlefield lasers | https://en.wikipedia.org/wiki?curid=23435856 |
M17 gas mask Old, clear outserts tended to yellow with time and was considered a deadlining condition for the mask since accurate color vision was required to assess sometimes subtle color changes on the M256A1 chemical detection kit required for unmasking procedures. The mask is packed in a carrier that also contains other items like a nerve agent antidote kit (NAAK), a convulsive antidote for nerve agents (CANA) and an M-258A1 decontamination kit. It also contains a M1 waterproof bag to protect filter elements from water damage. Other components attached are mask hoods to protect the head and neck area, a winterization kit to prevent frost accumulation during cold weather conditions and optical inserts for soldiers with vision defects. The M17A1 was designed with intent to allow a masked soldier to provide artificial respiration to an unmasked casualty, the resuscitation tube was a noble idea gone wrong. The problem with it being the exposure of both soldiers to contamination, the soldier giving aid ran the risk of encountering resistance from the airway of the casualty, pushing air back into his mask and breaking the seal on it. The casualty would remain unmasked, and would continue absorbing the contaminated environment. It was for this reason that the resuscitation tube system was no longer issued for the A1 and was dropped on the M17A2 | https://en.wikipedia.org/wiki?curid=23435856 |
M17 gas mask The design of the mask with its internal cheek filters means that it must be removed by the wearer to change the filters once they are expired or clogged, thus compromising its protective capabilities in a contaminated environment. The US armed forces henceforth returned to 'traditional' designs of mask where filter canisters are mounted externally and thus can be changed if needed without the wearer having to remove the mask. The mask offers protection from chemical and biological warfare agents, but does not function properly in places where oxygen content is low. The mask is not meant to be used for firefighting and does not provide protection from radiation, however the filters will stop irradiated particles from entering the respiratory system of the wearer. It is recommended that users continue wearing it until the biological or chemical agent is identified and verified cleared from the area using standardized unmasking procedures. | https://en.wikipedia.org/wiki?curid=23435856 |
Inverse magnetostrictive effect The inverse magnetostrictive effect, magnetoelastic effect or Villari effect is the change of the magnetic susceptibility of a material when subjected to a mechanical stress. The magnetostriction formula_1 characterizes the shape change of a ferromagnetic material during magnetization, whereas the inverse magnetostrictive effect characterizes the change of sample magnetization formula_2(for given magnetizing field strength formula_3) when mechanical stresses formula_4 are applied to the sample. Under a given uni-axial mechanical stress formula_4, the flux density formula_6 for a given magnetizing field strength formula_3 may increase or decrease. The way in which a material responds to stresses depends on its saturation magnetostriction formula_8. For this analysis, compressive stresses formula_4 are considered as negative, whereas tensile stresses are positive. According to Le Chatelier's principle: formula_10 This means, that when the product formula_11 is positive, the flux density formula_6 increases under stress. On the other hand, when the product formula_11 is negative, the flux density formula_6 decreases under stress. This effect was confirmed experimentally. In the case of a single stress formula_4 acting upon a single magnetic domain, the magnetic strain energy density formula_16 can be expressed as: formula_17 where formula_8 is the magnetostrictive expansion at saturation, and formula_19 is the angle between the saturation magnetization and the stress's direction | https://en.wikipedia.org/wiki?curid=23437336 |
Inverse magnetostrictive effect When formula_8 and formula_4 are both positive (like in iron under tension), the energy is minimum for formula_19 = 0, i.e. when tension is aligned with the saturation magnetization. Consequently, the magnetization is increased by tension. In fact, magnetostriction is more complex and depends on the direction of the crystal axes. In iron, the [100] axes are the directions of easy magnetization, while there is little magnetization along the [111] directions (unless the magnetization becomes close to the saturation magnetization, leading to the change of the domain orientation from [111] to [100]). This magnetic anisotropy pushed authors to define two independent longitudinal magnetostrictions formula_23 and formula_24. Method suitable for effective testing of magnetoelastic effect in magnetic materials should fulfill the following requirements: Following testing methods were developed: Magnetoelastic effect can be used in development of force sensors. This effect was used for sensors: Magnetoelastic effect have to be also considered as a side effect of accidental application of mechanical stresses to the magnetic core of inductive component, e.g. fluxgates. | https://en.wikipedia.org/wiki?curid=23437336 |
Alpha-aminoadipate pathway The α-aminoadipate pathway is a biochemical pathway for the synthesis of the amino acid -lysine. In the eukaryotes, this pathway is unique to the higher fungi (containing chitin in their cell walls) and the euglenids. It has also been reported from bacteria of the genus "Thermus". Homocitrate is initially synthesised from acetyl-CoA and 2-oxoglutarate by homocitrate synthase. This is then converted to homoaconitate by homoaconitase and then to homoisocitrate by homoisocitrate dehydrogenase. A nitrogen atom is added from glutamate by aminoadipate aminotransferase to form the α-aminoadipate from which this pathway gets its name. This is then reduced by aminoadipate reductase via an acyl-enzyme intermediate to a semialdehyde. Reaction with glutamate by one class of saccharopine dehydrogenase yields saccharopine which is then cleaved by a second saccharopine dehydrogenase to yield lysine and oxoglutarate. α-Aminoadipic acid is an intermediate in the α-Aminoadipic acid pathway for the metabolism of lysine and saccharopine. It is synthesised from homoisocitrate by aminoadipate aminotransferase and reduced by aminoadipate reductase to form the semialdehyde. A 2013 study identified α-Aminoadipic acid (2-aminoadipic acid) as "a novel predictor of the development of diabetes" and suggested that it is "a potential modulator of glucose homeostasis in humans". | https://en.wikipedia.org/wiki?curid=23440465 |
C5H14N2 The molecular formula CHN (molar mass : 102.17 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23443297 |
C15H24 The molecular formula CH (molar mass : 204.35 g/mol) may refer to: | https://en.wikipedia.org/wiki?curid=23443332 |
C20H28O3 The molecular formula CHO may refer to: | https://en.wikipedia.org/wiki?curid=23443347 |
C21H26O2 The molecular formula CHO (molar mass : 310.42 g/mol, exact mass : 310.19328) may refer to: | https://en.wikipedia.org/wiki?curid=23443604 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.