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Isotopes of livermorium Livermorium (Lv) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was Lv in 2000. There are four known radioisotopes from Lv to Lv, as well as a few suggestive indications of ... | https://en.wikipedia.org/wiki?curid=2527270 |
Isotopes of livermorium There are no published results on the outcome, presumably indicating that no atoms were detected. This is expected from a study of the systematics of cross sections for U targets. The first attempt to synthesise livermorium was performed in 1977 by Ken Hulet and his team at the Lawrence Livermor... | https://en.wikipedia.org/wiki?curid=2527270 |
Isotopes of livermorium In this reaction, 2 further atoms of Lv were detected. In 2007, in a GSI-SHIP experiment, besides four Lv chains and one Lv chain, another chain was observed, initially not assigned but later shown to be Lv. However, it is unclear whether it comes from the Cm(Ca,5n) reaction or from a reaction w... | https://en.wikipedia.org/wiki?curid=2527270 |
Isotopes of livermorium The observation of the daughter Lv allowed the assignment of the parent to Og and proved the synthesis of oganesson. Several experiments have been performed between 2000 and 2006 at the Flerov Laboratory of Nuclear Reactions in Dubna studying the fission characteristics of the compound nuclei Lv... | https://en.wikipedia.org/wiki?curid=2527270 |
Isotopes of livermorium The table below provides cross-sections and excitation energies for hot fusion reactions producing livermorium isotopes directly. Data in bold represent maxima derived from excitation function measurements. + represents an observed exit channel. Theoretical calculation in a quantum tunneling mod... | https://en.wikipedia.org/wiki?curid=2527270 |
Isotopes of tennessine Tennessine (Ts) is the most-recently synthesized synthetic element, and much of the data is hypothetical. As for any synthetic element, a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first (and so far only) isotopes to be synthesized were Ts ... | https://en.wikipedia.org/wiki?curid=2527272 |
Isotopes of tennessine Initial decay data was published as a preliminary presentation on the JINR website. A further experiment in May 2010, aimed at studying the chemistry of the granddaughter of tennessine, nihonium, identified a further two atoms of Nh from the decay of Ts. The original experiment was repeated succe... | https://en.wikipedia.org/wiki?curid=2527272 |
Isotopes of oganesson Oganesson (Og) is a synthetic element created in particle accelerators, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first (and so far only) isotope to be synthesized was Og in 2002 and 2005; it has a half-life of 0.7 milliseconds. ... | https://en.wikipedia.org/wiki?curid=2527278 |
Isotopes of oganesson Following successful experiments utilizing calcium-48 projectiles and actinide targets to generate elements 114 and 116, the search for element 118 was first performed at the Joint Institute for Nuclear Research (JINR) in 2002. One or two atoms of Og were produced in the 2002 experiment, and two m... | https://en.wikipedia.org/wiki?curid=2527278 |
Isotopes of oganesson One event of Og was found at the lower beam energy, while no decays of oganesson isotopes were found at the higher beam energy; a cross section of 0.9 pb for the Cf(Ca,3n) was estimated. In the same experiment, these reactions were performed in a search for Og and Og. No events attributable to a r... | https://en.wikipedia.org/wiki?curid=2527278 |
Isotopes of oganesson DNS = Di-nuclear system; 2S = Two-step; σ = cross section | https://en.wikipedia.org/wiki?curid=2527278 |
Solid phase extraction Solid-phase extraction (SPE) is an extractive technique by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate a... | https://en.wikipedia.org/wiki?curid=2527405 |
Solid phase extraction It is an extractive technique, a solid-liquid extractive technique—taking advantage of large differences in the Keq, or Equilibrium constant, of mixture components between the solid phase and the mobile phase resulting, for a well-designed and executed separation, in a bulk separation of one or m... | https://en.wikipedia.org/wiki?curid=2527405 |
Solid phase extraction As the sample passes through the stationary phase, the polar analytes in the sample will interact and retain on the polar sorbent while the solvent, and other non-polar impurities pass through the cartridge. After the sample is loaded, the cartridge is washed with a non-polar solvent to remove fu... | https://en.wikipedia.org/wiki?curid=2527405 |
Solid phase extraction Anion exchange sorbents are derivatized with positively charged functional groups that interact and retain negatively charged anions, such as acids. Strong anion exchange sorbents contain quaternary ammonium groups that have a permanent positive charge in aqueous solutions, and weak anion exchang... | https://en.wikipedia.org/wiki?curid=2527405 |
Solid phase extraction Strong cation exchange sorbents are useful because any strongly basic impurities in the sample will bind to the sorbent and usually will not be eluted with the analyte of interest; to recover a strong base a weak cation exchange cartridge should be used. To elute the analyte from either the stron... | https://en.wikipedia.org/wiki?curid=2527405 |
Solid phase extraction Most stationary phases are based on silica that has been bonded to a specific functional group. Some of these functional groups include hydrocarbon chains of variable length (for reversed phase SPE), quaternary ammonium or amino groups (for anion exchange), and sulfonic acid or carboxyl groups (f... | https://en.wikipedia.org/wiki?curid=2527405 |
Trace heating Electric heat tracing, heat tape or surface heating, is a system used to maintain or raise the temperature of pipes and vessels using heat tracing cables. takes the form of an electrical heating element run in physical contact along the length of a pipe. The pipe is usually covered with thermal insulation... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating One paper projected that between 2000 and 2010 trace heating would account for 100 megawatts of connected load, and that trace heating and insulation would account for up to CAD $700 million capital investment in the Alberta oil sands. International standards applied in the design and installation of elec... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating Hot water service piping can also be traced, so that a circulating system is not needed to provide hot water at outlets. The combination of trace heating and the correct thermal insulation for the operating ambient temperature maintains a thermal balance where the heat output from the trace heating matche... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating As heating a thick fluid decreases its viscosity, it reduces losses occurring in a pipe. Therefore, the net positive suction head (pressure difference) available can be raised, decreasing the likelihood of cavitation when pumping. However, care must be taken not to increase the vapour pressure of the flui... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating A constant wattage cable is composed of multiple constant electric power zones and is made by wrapping a fine heating element around two insulated parallel bus wires, then on alternating sides of the conductors a notch is made in the insulation. The heating element is then normally soldered to the exposed... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating The disadvantage of this cable is that most constant wattage cables do not have soldered connections to the bus wires but press on type contact and are therefore more prone to have cold circuits due to loose connections caused by cable manipulation and installation. Self-regulating heat tracing tapes are ... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating Self-regulating and constant wattage heating cables have specific maximum exposure temperature, which means that if they are subject to high temperatures then the tape can be damaged beyond repair. Also self-limiting tapes are subject to higher inrush currents on cold starting up similar to an induction m... | https://en.wikipedia.org/wiki?curid=2527535 |
Trace heating This thawing out is done on the three phase systems by using an 'auto transformer' to give a higher voltage, and consequently higher current, and make the trace heating elements a bit hotter. The boost system is usually on a timer and switches back to 'normal' after a period of time. | https://en.wikipedia.org/wiki?curid=2527535 |
Cryoprotectant A cryoprotectant is a substance used to protect biological tissue from freezing damage (i.e. that due to ice formation). Arctic and Antarctic insects, fish and amphibians create cryoprotectants (antifreeze compounds and antifreeze proteins) in their bodies to minimize freezing damage during cold winter p... | https://en.wikipedia.org/wiki?curid=2528127 |
Cryoprotectant Some cryoprotectants function by lowering the glass transition temperature of a solution or of a material. In this way, the cryoprotectant prevents actual freezing, and the solution maintains some flexibility in a glassy phase. Many cryoprotectants also function by forming hydrogen bonds with biological ... | https://en.wikipedia.org/wiki?curid=2528127 |
Cryoprotectant Ethylene glycol is commonly used as automobile antifreeze; while propylene glycol has been used to reduce ice formation in ice cream. Dimethyl sulfoxide (DMSO) is also regarded as a conventional cryoprotectant. Glycerol and DMSO have been used for decades by cryobiologists to reduce ice formation in sper... | https://en.wikipedia.org/wiki?curid=2528127 |
Cryoprotectant When the frog rewarms during spring, the extra glucose must be rapidly eliminated, but stored. Cryoprotectants are also used to preserve foods. These compounds are typically sugars that are inexpensive and do not pose any toxicity concerns. For example, many (raw) frozen chicken products contain a sucros... | https://en.wikipedia.org/wiki?curid=2528127 |
Volatility (chemistry) In chemistry, volatility is a material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a vapor, while a substance with low volatility is more likely to be a liquid or solid. Volatility can ... | https://en.wikipedia.org/wiki?curid=2528589 |
Volatility (chemistry) Vapor pressure is a measurement of how readily a condensed phase forms a vapor at a given temperature. A substance enclosed in a sealed vessel initially at vacuum (no air inside) will quickly fill any empty space with vapor. After the system reaches equilibrium and no more vapor is formed, this v... | https://en.wikipedia.org/wiki?curid=2528589 |
Volatility (chemistry) The result in an overall stronger attractive force between the ethanol molecules, making it the less volatile substance of the two. In general, volatility tends to decrease with increasing molecular mass, although other factors such as structure and polarity play a significant role. The effect of... | https://en.wikipedia.org/wiki?curid=2528589 |
Volatility (chemistry) These vapors move up the tower and eventually come in contact with cold surfaces, which causes them to condense and be collected. The most volatile chemical condense at the top of the column while the least volatile chemicals to vaporize condense in the lowest portion. On the right is a picture i... | https://en.wikipedia.org/wiki?curid=2528589 |
Diazonium compound Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halogen. According to tabulated linear free energy relationship constants (e.g. Ha... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound Methyldiazonium carboxylate is believed to be a fleeting intermediate in the methylation of carboxylic acids by diazomethane, and alkyldiazonium species generated via diazotization of amines have been studied in physical organic chemistry studies. However, alkyldiazonium salts are otherwise synthetic... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound Aryldiazonium salts are exceptionally versatile reagents for chemical synthesis. Because aryl radicals and cations are highly electrophilic and will react with virtually any nucleophile reagent, aryldiazonium salts form a "transit hub" for arene chemistry from which almost any other aromatic derivati... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound Usually the nitrous acid is generated "in situ" (in the same flask) from sodium nitrite and the excess mineral acid (usually aqueous HCl, HSO, "p"-HCCHSOH, or HBF): Aqueous solutions of diazonium chloride salts, traditionally prepared from the aniline, sodium nitrite, and hydrochloric acid, are unsta... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound For example, the dye called aniline yellow is produced by mixing aniline and cold solution of diazonium salt and then shaking it vigorously. Aniline yellow is obtained as a yellow solid. Similarly, a cold basic solution of Naphthalen-2-ol (beta-naphthol) give the intensely orange-red precipitate. Met... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound The traditional Balz–Schiemann reaction has been the subject of many motivations, e.g. using hexafluorophosphates (PF) and hexafluoroantimonate (SbF) in place of tetrafluoroborates. The diazotization can be effected with nitrosonium salts such as [NO]SbF. Arenediazonium cations reduced by hypophospho... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound In contrast, Fu reported the trifluoromethylation using Umemoto's reagent ("S"-trifluoromethyldibenzothiophenium tetrafluoroborate) and Cu powder (Gattermann-type conditions). They can be described by the following equation: The bracket indicates that other ligands on copper are likely present but ar... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound In a potential application in nanotechnology, the diazonium salts 4-chlorobenzenediazonium tetrafluoroborate very efficiently functionalizes single wall nanotubes. In order to exfoliate the nanotubes, they are mixed with an ionic liquid in a mortar and pestle. The diazonium salt is added together wit... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound The metals to the left of iron are positioned tilted towards or flat on the surface favoring metal to carbon pi bond formation and those on the right of iron are positioned in an upright position, favoring metal to carbon sigma bond formation. This also explains why diazonium salt grafting thus far h... | https://en.wikipedia.org/wiki?curid=2531152 |
Diazonium compound This property has led to their use in document reproduction. In this process, paper or film is coated with a diazonium salt. After contact exposure under light, the residual diazo is converted to a stable azo dye with an aqueous solution of coupler. A more common process uses a paper coated with diaz... | https://en.wikipedia.org/wiki?curid=2531152 |
Methanandamide (AM-356) is a synthetically created stable chiral analog of anandamide. Its effects have been observed to act on the cannabinoid receptors (specifically on CB receptors, which are part of the central nervous system) found in different organisms such as mammals, fish, and certain invertebrates (e.g. "Hydr... | https://en.wikipedia.org/wiki?curid=2532134 |
List of fictional elements, materials, isotopes and subatomic particles This list contains fictional chemical elements, materials, isotopes or subatomic particles that either a) play a major role in a notable work of fiction, b) are common to several unrelated works, or c) are discussed in detail by independent sources... | https://en.wikipedia.org/wiki?curid=2533091 |
Catalytic triad A catalytic triad is a set of three coordinated amino acids that can be found in the active site of some enzymes. Catalytic triads are most commonly found in hydrolase and transferase enzymes (e.g. proteases, amidases, esterases, acylases, lipases and β-lactamases). An Acid-Base-Nucleophile triad is a c... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad The structure of chymotrypsin was solved by X-ray crystallography in the 1960s, showing the orientation of the catalytic triad in the active site. Other proteases were sequenced and aligned to reveal a family of related proteases, now called the S1 family. Simultaneously, the structures of the evolution... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad The massive body of work on the charge-relay, covalent catalysis used by catalytic triads has led to the mechanism being the best characterised in all of biochemistry. Enzymes that contain a catalytic triad use it for one of two reaction types: either to split a substrate (hydrolases) or to transfer one... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad The intermediate then collapses back to a carbonyl, ejecting the first half of the substrate, but leaving the second half still covalently bound to the enzyme as an acyl-enzyme intermediate. The ejection of this first leaving group is often aided by donation of a proton by the base. The second stage of ... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Use of oxygen or sulfur as the nucleophilic atom causes minor differences in catalysis. Compared to oxygen, sulfur's extra d orbital makes it larger (by 0.4 Å) and softer, allows it to form longer bonds (d and d by 1.3-fold), and gives it a lower p"K" (by 5 units). Serine is therefore more dependent tha... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Additionally, it protonates the first product to aid leaving group departure. The base is most commonly histidine since its p"K" allows for effective base catalysis, hydrogen bonding to the acid residue, and deprotonation of the nucleophile residue. β-lactamases such as TEM-1 use a lysine residue as the... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Similarly, hepatitis A virus protease contains an ordered water in the position where an acid residue should be. The Serine-Histidine-Aspartate motif is one of the most thoroughly characterised catalytic motifs in biochemistry. The triad is exemplified by chymotrypsin, a model serine protease from the P... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Due to cysteine's low p"K", the importance of the Asp to catalysis varies and several cysteine proteases are effectively Cys-His dyads (e.g. hepatitis A virus protease), whilst in others the cysteine is already deprotonated before catalysis begins (e.g. papain). This triad is also used by some amidases,... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Threonine proteases, such as the proteasome protease subunit and ornithine acyltransferases use the secondary hydroxyl of threonine in a manner analogous to the use of the serine primary hydroxyl. However, due to the steric interference of the extra methyl group of threonine, the base member of the tria... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad Selenocysteine is similar to cysteine, but contains a selenium atom instead of a sulfur. An example is in the active site of thioredoxin reductase, which uses the selenium for reduction of disulfide in thioredoxin. In addition to naturally occurring types of catalytic triads, protein engineering has bee... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad The Ser-His-Asp triad has been inserted into an antibody, as well as a range of other proteins. Similarly, catalytic triad mimics have been created in small organic molecules like diaryl diselenide, and displayed on larger polymers like Merrifield resins, and self-assembling short peptide nanostructures... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad In different members of the α/β-hydrolase superfamily, the Ser-His-Asp triad is tuned by surrounding residues to perform at least 17 different reactions. Some of these reactions are also achieved with mechanisms that have altered formation, or resolution of the acyl-enzyme intermediate, or that don't pr... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad For example, the heparin-binding protein Azurocidin is a member of the PA clan, but with a glycine in place of the nucleophile and a serine in place of the histidine. Similarly, RHBDF1 is a homolog of the S54 family rhomboid proteases with an alanine in the place of the nucleophilic serine. In some case... | https://en.wikipedia.org/wiki?curid=2533237 |
Catalytic triad These triads have converged to almost the same arrangement due to the mechanistic similarities in cysteine and serine proteolysis mechanisms. Families of cysteine proteases Families of serine proteases Threonine proteases use the amino acid threonine as their catalytic nucleophile. Unlike cysteine and s... | https://en.wikipedia.org/wiki?curid=2533237 |
Pressure piling describes phenomena related to combustion of gases in a tube or long vessel. As the flame front propagates along the tube, the unburned gases ahead of the front are compressed, and hence heated. The amount of compression varies depending on the geometry and can range from twice to eight times the initia... | https://en.wikipedia.org/wiki?curid=2534136 |
Sodium dithiophosphate is the salt with the formula NaPSO. It is usually supplied as the hydrated solid or as an aqueous solution together with other thiophosphates such as sodium monothiophosphate and sodium trithiophosphate. It is a colorless compound, but commercial samples can appear dark owing to the presence of i... | https://en.wikipedia.org/wiki?curid=2534393 |
Hydrodynamic focusing is a technique used to provide more accurate results from flow cytometers or Coulter counters for determining the size of bacteria or cells. Cells are counted as they are forced to pass through a small channel (often referred to as a flow cell), causing disruptions in a laser light beam or electri... | https://en.wikipedia.org/wiki?curid=2534396 |
Regelation is the phenomenon of melting under pressure and refreezing when the pressure is reduced. We can demonstrate regelation by looping a fine wire around a block of ice, with a heavy weight attached to it. The pressure exerted on the ice slowly melts it locally, permitting the wire to pass through the entire bloc... | https://en.wikipedia.org/wiki?curid=2534487 |
Regelation Simulations of ice near to its melting point show that there is significant melting of the surface layers rather than a symmetric relaxation of atom positions. Nuclear magnetic resonance provided evidence for a liquid layer on the surface of ice. In 1998, using atomic force microscopy, Astrid Döppenschmidt a... | https://en.wikipedia.org/wiki?curid=2534487 |
Regelation Neither the case of liquid forms on ice nor ice layer covers water, but the supersolid skin slipperizes ice and toughens the water skin Hydrogen bond (O:H-O) relaxation under compression. Compression shortens and stiffens the O:H nonbond and simultaneously lengthens and softens the H-O covalent bond, and neg... | https://en.wikipedia.org/wiki?curid=2534487 |
Nanotribology is the branch of tribology that studies friction, wear, adhesion and lubrication phenomena at the nanoscale, where atomic interactions and quantum effects are not negligible. The aim of this discipline is characterizing and modifying surfaces for both scientific and technological purposes. Nanotribologica... | https://en.wikipedia.org/wiki?curid=2536597 |
Nanotribology On the other hand, in nanotribology, the systems studied are composed of nanometric structures, where volume forces (such as those related to mass and gravity) can often be considered negligible compared to surface forces. Scientific equipment to study such systems have been developed only in the second h... | https://en.wikipedia.org/wiki?curid=2536597 |
Nanotribology "Nanotribology" was first defined as a sub-field of tribology encompassing a range of experimental and computational methods in a 1991 publication reporting QCM measurements of the sliding friction levels of one-atom thick films. From the beginning of the 21st century, computer-based atomic simulation met... | https://en.wikipedia.org/wiki?curid=2536597 |
Nanotribology Normal forces can be measured by a simple relation: formula_1 where formula_2 is the applied displacement by using one of the control methods mentioned before, formula_3 is the spring constant and formula_4 is the actual deformation of the sample measured by MBI. Moreover, if formula_5 then there is a mec... | https://en.wikipedia.org/wiki?curid=2536597 |
Nanotribology In nanotribology AFM is commonly used for measuring normal and friction forces with a resolution of pico-Newtons. The tip is brought close to the sample's surface, consequently forces between the last atoms of the tip and the sample's deflect the cantilever proportionally to the intensity of this interact... | https://en.wikipedia.org/wiki?curid=2536597 |
Massicot is lead (II) oxide mineral with an orthorhombic lattice structure. Lead(II) oxide (formula: PbO) can occur in one of two lattice formats, orthorhombic and tetragonal. The tetragonal form is called litharge. PbO can be changed from massicot to litharge (or vice versa) by controlled heating and cooling. At room ... | https://en.wikipedia.org/wiki?curid=2537332 |
Ideal chain An ideal chain (or freely-jointed chain) is the simplest model to describe polymers, such as nucleic acids and proteins. It only assumes a polymer as a random walk and neglects any kind of interactions among monomers. Although it is simple, its generality gives insight about the physics of polymers. In this... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain Most of the expressions given in this article assume that the number of mers "N" is large, so that the central limit theorem applies. The figure below shows a sketch of a (short) ideal chain. The two ends of the chain are not coincident, but they fluctuate around each other, so that of course: Throughout th... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain Mathematical remark: the rigorous demonstration of the expression of the density of probability formula_17 is not as direct as it appears above: from the application of the usual (1D) central limit theorem one can deduce that formula_18, formula_19 and formula_9 are distributed according to a centered norma... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain The relevancy of the model is, however, limited, even at the macroscopic scale, by the fact that it does not consider any excluded volume for monomers (or, to speak in chemical terms, that it neglects steric effects). Other fluctuating polymer models that consider no interaction between monomers and no excl... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain What is the microscopic origin of such an entropic force or pressure? The most general answer is that the effect of thermal fluctuations tends to bring a thermodynamic system toward a macroscopic state that corresponds to a maximum in the number of microscopic states (or micro-states) that are compatible wi... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain The case of an ideal chain whose two ends are attached to fixed points will be considered in this sub-section. The vector formula_2 joining these two points characterizes the macroscopic state (or macro-state) of the ideal chain. Each macro-state corresponds a certain number of micro-states, that we will ca... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain If the operator changes formula_2 by a tiny amount formula_46, then the variation of internal energy of the chain is zero, since the energy of the chain is constant. This condition can be written as: formula_48 is defined as the elementary amount of mechanical work transferred by the operator to the ideal c... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain For the arbitrary extensions the force-extension dependence can be approximated by: where formula_62 is the inverse Langevin function, N is the number of bonds in the molecule (therefore if the molecule has N bonds it has N+1 monomers making up the molecule.). Finally, the model can be extended to even larg... | https://en.wikipedia.org/wiki?curid=2537711 |
Ideal chain The parameter in question is energy for the microcanonical and canonical descriptions, whereas in the case of the ideal chain the parameter is the length of the ideal chain. As in the micro-canonical and canonical ensembles, the two descriptions of the ideal chain differ only in the way they treat the syste... | https://en.wikipedia.org/wiki?curid=2537711 |
Wood gas generator A wood gas generator is a gasification unit which converts timber or charcoal into wood gas, a syngas consisting of atmospheric nitrogen, carbon monoxide, hydrogen, traces of methane, and other gases, which - after cooling and filtering - can then be used to power an internal combustion engine or for... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator During the late 19th century internal combustion engines were commonly fueled by town gas, and during the early 20th century many stationary engines switched to using producer gas created from coke which was substantially cheaper than town gas which was based on the distillation (pyrolysis) of more e... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator However, Great Britain continued her use of coal-based town gas until the North Sea natural gas discoveries in the 1960s and 1970s. When oil prices rose there was renewed interest in wood gas generators. The US Federal Emergency Management Agency (FEMA) published a book in March 1989 describing how t... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator This simplified design has distinct benefits over the earlier European units such as easier refueling and construction but is less popular than the earlier Imbert design because of significant new problems, which include a lack of a fixed oxidization zone and allows the oxidization zone to creep to a... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator Wood gasifiers of proven design and thoroughly tested construction are considered safe to use outdoors, or in a partially enclosed space, for example, under a shelter open to the air on two sides; they may also be considered relatively safe to use in an extremely well ventilated (e.g. negative pressu... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator In 2008, an example of designing and constructing a working wood gas generator powered truck was shown on the National Geographic Channel's "Planet Mechanics" in the eighth episode, "Tree Powered Car". In 2009, another example of designing and constructing a working wood gas powered generator engine ... | https://en.wikipedia.org/wiki?curid=2541603 |
Wood gas generator On March 12, 2012, on a season 2 episode of Doomsday Preppers, a wood gas generator is shown running a Ford truck and a house electric generator by prepper Scott Hunt on his multi-acre woodland property in South Carolina. Serbian TV sitcom "Truckdrivers 2" (="Kamiondzije II") from 1983. talks, as a p... | https://en.wikipedia.org/wiki?curid=2541603 |
Electrical equipment in hazardous areas In electrical engineering, hazardous locations (sometimes abbreviated to HazLoc, pronounced "Haz·Lōk") are defined as places where fire or explosion hazards may exist due to flammable gases, flammable liquid–produced vapors, combustible liquid–produced vapors, combustible dusts, ... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas A household light switch may emit a small, harmless visible spark when switching. In an ordinary atmosphere this arc is of no concern, but if a flammable vapor is present, the arc might start an explosion. Electrical equipment intended for use in a chemical factory or refinery ei... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Heat producing elements such as motor winding, electrical heaters, including heat tracing and lighting fixtures are often designed to limit their maximum temperature below the autoignition temperature of the material involved. Both external and internal temperatures are taken int... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Area classification documentations are reviewed and updated to reflect process changes. Soon after the introduction of electric power into coal mines, it was discovered that lethal explosions could be initiated by electrical equipment such as lighting, signals, or motors. The haz... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Guidance on assessing the extent of the hazard is given in the NFPA 497 or NFPA 499 standards published by the National Fire Protection Association for explosive gas or dust atmospheres respectively, or RP 500 and RP 505 standards published by the American Petroleum Institute, an... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Flammable dusts when suspended in air can explode. An old system of area classification to a British standard used a system of letters to designate the zones. This has been replaced by a European numerical system, as set out in directive 1999/92/EU implemented in the UK as the Da... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas A material may have a relatively low autoignition temperature yet if its flash-point is above the ambient temperature, then the area may not need to be classified. Conversely if the same material is heated and handled above its flash-point, the area must be classified for proper ... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas The surface temperature or any parts of the electrical equipment that may be exposed to the hazardous atmosphere should be tested that it does not exceed 80% of the auto-ignition temperature of the specific gas or vapor in the area where the equipment is intended to be used. The ... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Although there are many types of protection, a few are detailed The types of protection are subdivided into several sub classes, linked to EPL: ma and mb, px, py and pz, ia, ib and ic. The a subdivisions have the most stringent safety requirements, taking into account more the on... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas Industrial electrical equipment for hazardous area has to conform to appropriate parts of standard IEC 60079 for gas hazards, and IEC 61241 for dust hazards, and in some cases, be certified as meeting that standard. Independent test houses (known as Notified Bodies) are establish... | https://en.wikipedia.org/wiki?curid=2542454 |
Electrical equipment in hazardous areas 1 suitability and their listing as approved method of installation in the NEC serves as the permission. Some equipment in Division 2 areas do not require a specific label, such as standard 3 phase induction motors that do not contain normally arcing components. Also included in t... | https://en.wikipedia.org/wiki?curid=2542454 |
Uranium rhodium germanium "Grenoble High Magnetic Field Laboratory", published in August 2005's issue of "Science", that uranium rhodium germanium (URhGe) is the first discovered metal that becomes superconducting in the presence of an extremely strong electromagnetic field. Very unlike other superconducting materials,... | https://en.wikipedia.org/wiki?curid=2542693 |
SH2 domain The SH2 (Src Homology 2) domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins. SH2 domains allow proteins containing those domains to dock to phosphorylated tyrosine residues on other proteins. SH2 domains are commo... | https://en.wikipedia.org/wiki?curid=2544024 |
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