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Rare-earth element Yttrium is grouped as heavy rare-earth element due to chemical similarities. The 1985 International Union of Pure and Applied Chemistry “Red Book” (p. 45) recommends that "lanthanoid" is used rather than "lanthanide". The ending “-ide” normally indicates a negative ion. However, owing to wide current... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Due to their chemical similarity, the concentrations of rare earths in rocks are only slowly changed by geochemical processes, making their proportions useful for geochronology and dating fossils. cerium is actually the 25th most abundant element in Earth's crust, having 68 parts per million (about a... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element The larger ionic radii of LREE make them generally more incompatible than HREE in rock-forming minerals, and will partition more strongly into a melt phase, while HREE may prefer to remain in the crystalline residue, particularly if it contains HREE-compatible minerals like garnet. The result is that... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Similar compositions are found in xenotime or gadolinite. Well-known minerals containing yttrium, and other HREE, include gadolinite, xenotime, samarskite, euxenite, fergusonite, yttrotantalite, yttrotungstite, yttrofluorite (a variety of fluorite), thalenite, yttrialite. Small amounts occur in zirco... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Enriched deposits of rare-earth elements at the surface of the Earth, carbonatites and pegmatites, are related to alkaline plutonism, an uncommon kind of magmatism that occurs in tectonic settings where there is rifting or that are near subduction zones. In a rift setting, the alkaline magma is produ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Carbonatites crystallize from CO-rich fluids, which can be produced by partial melting of hydrous-carbonated lherzolite to produce a CO-rich primary magma, by fractional crystallization of an alkaline primary magma, or by separation of a CO-rich immiscible liquid from. These liquids are most commonly... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Economically viable pegmatites are divided into Lithium-Cesium-Tantalum (LCT) and Niobium-Yttrium-Fluorine (NYF) types; NYF types are enriched in rare-earth minerals. Examples of rare-earth pegmatite deposits include Strange Lake in Canada, and Khaladean-Buregtey in Mongolia. Nepheline syenite (M-Typ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element REE may also by extracted from placer deposits if the sedimentary parent lithology contained REE-bearing, heavy resistate minerals. In 2011, Yasuhiro Kato, a geologist at the University of Tokyo who led a study of Pacific Ocean seabed mud, published results indicating the mud could hold rich concentr... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element In geochemistry, rare-earth elements are typically presented in normalized "spider" diagrams, in which concentration of rare-earth elements are normalized to a reference standard and are then expressed as the logarithm to the base 10 of the value. Commonly, the rare-earth elements are normalized to c... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element If an element preferentially remains in the solid phase it is termed ‘compatible’, and it preferentially partitions into the melt phase it is described as ‘incompatible’. Each element has a different partition coefficient, and therefore fractionates into solid and liquid phases distinctly. These conc... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element In oceans, rare-earth elements reflect input from rivers, hydrothermal vents, and aeolian sources; this is important in the investigation of ocean mixing and circulation. Rare-earth elements are also useful for dating rocks, as some radioactive isotopes display long half-lives. Of particular interest... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Increased demand has strained supply, and there is growing concern that the world may soon face a shortage of the rare earths. In several years from 2009 worldwide demand for rare-earth elements is expected to exceed supply by 40,000 tonnes annually unless major new sources are developed. In 2013, it... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element On October 19, 2010, "China Daily", citing an unnamed Ministry of Commerce official, reported that China will "further reduce quotas for rare[-]earth exports by 30 percent at most next year to protect the precious metals from over-exploitation." The government in Beijing further increased its control... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element In response to the opening of new mines in other countries (Lynas in Australia and Molycorp in the United States), prices of rare earths dropped. The price of dysprosium oxide was 994 USD/kg in 2011, but dropped to US$265/kg by 2014. On August 29, 2014, the WTO ruled that China had broken free-trade ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Other significant sites under development outside of China include Steenkampskraal in South Africa, the world's highest grade rare earths and thorium mine, which is gearing to go back into production. Over 80% of the infrastructure is already complete. Other mines include the Nolans Project in Centra... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element The European Union has urged Greenland to restrict Chinese development of rare-earth projects there, but as of early 2013, the government of Greenland has said that it has no plans to impose such restrictions. Many Danish politicians have expressed concerns that other nations, including China, could ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element The ore would be trucked to Fremantle and transported by container ship to Kuantan. Within two years, Lynas was said to expect the refinery to be able to meet nearly a third of the world's demand for rare-earth materials, not counting China. The Kuantan development brought renewed attention to the Ma... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Significant quantities of rare-earth oxides are found in tailings accumulated from 50 years of uranium ore, shale and loparite mining at Sillamäe, Estonia. Due to the rising prices of rare earths, extraction of these oxides has become economically viable. The country currently exports around 3,000 to... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element New advances in recycling technology have made extraction of rare earths from these materials more feasible, and recycling plants are currently operating in Japan, where there is an estimated 300,000 tons of rare earths stored in unused electronics. In France, the Rhodia group is setting up two facto... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Ce, Ga and Nd are important in electronics and are used in the production of LCD and plasma screens, fiber optics, lasers, as well as in medical imaging. Additional uses for rare-earth elements are as tracers in medical applications, fertilizers, and in water treatment. REEs have been used in agricul... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Acting much like metals they can speciate depending on the soil condition being either motile or adsorbed to soil particles. Depending on their bio-availability REEs can be absorbed into plants and later consumed by humans and animals. Including the mining of REEs and REE-enriched fertilizers, the pr... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element This campaign is expected to be concentrated in the South, where mines – commonly small, rural, and illegal operations – are particularly prone to releasing toxic wastes into the general water supply. However, even the major operation in Baotou, in Inner Mongolia, where much of the world's rare-earth... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element New restrictions were announced by the Malaysian government in late June. IAEA panel investigation is completed and no construction has been halted. Lynas is on budget and on schedule to start producing 2011. The IAEA report has concluded in a report issued on Thursday June 2011 said it did not find ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Also, the ability for the vegetation to intake the REE is dependent on the type of REE present in the soil, hence there are a multitude of factors that influence this process. Agricultural plants are the main type of vegetation affected by REE contamination in the environment. Also, the main two plan... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element It has been demonstrated that numerous REEs have toxic properties and are present in the environment or in work places. Exposure to these can lead to a wide range of negative health outcomes such as cancer, respiratory issues, dental loss including death. However these elements are numerous and prese... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element Hence, it can impact their IQ and can cause memory loss. The rare earth mining and smelting process can release airborne fluoride which will associated with total suspended particles (TSP) to form aerosols that can enter human's respiratory systems and cause damage and respiratory diseases. a researc... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element REEs have been added to feed in livestock to increase their body mass and increase milk production. They are most-commonly used to increase the body mass of pigs and it was discovered that REEs increase the digestibility and nutrient use of pigs digestive system. Studies point to a dose response when... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element According to "The Economist", "Slashing their exports of rare-earth metals… is all about moving Chinese manufacturers up the supply chain, so they can sell valuable finished goods to the world rather than lowly raw materials." Furthermore, China currently has an effective monopoly on the world's REE ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element " The United States Department of Energy in its 2010 Critical Materials Strategy report identified dysprosium as the element that was most critical in terms of import reliance. A 2011 report "China's Rare-Earth Industry", issued by the US Geological Survey and US Department of the Interior, outlines ... | https://en.wikipedia.org/wiki?curid=145440 |
Rare-earth element The export quota for rare-earth products may be about 35,000 [metric tons] and the Government may allow 20 domestic rare-earth producers and traders to export rare earths." The United States Geological Survey is actively surveying southern Afghanistan for rare-earth deposits under the protection of U... | https://en.wikipedia.org/wiki?curid=145440 |
Parts-per notation In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement.... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation For instance, the accuracy of land-survey distance measurements when using a laser rangefinder might be 1 millimeter per kilometer of distance; this could be expressed as “Accuracy = 1 ppm.” Parts-per notations are all dimensionless quantities: in mathematical expressions, the units of measurement al... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation In nuclear magnetic resonance spectroscopy (NMR), chemical shift is usually expressed in ppm. It represents the difference of a measured frequency in parts per million from the reference frequency. The reference frequency depends on the instrument's magnetic field and the element being measured. It i... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation Because the named numbers starting with a “billion” have different values in different countries, the BIPM suggests avoiding the use of “ppb” and “ppt” to prevent misunderstanding. The U.S. National Institute of Standards and Technology (NIST) takes the stringent position, stating that "“the language... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation , ppmw, ppbw). The usage of the parts-per notation is generally quite fixed inside most specific branches of science, leading some researchers to draw the conclusion that their own usage (mass/mass, mol/mol, volume/volume, or others) is the only correct one. This, in turn, leads them to not specify t... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation This unit name "uno" and its symbol could be used in combination with the SI prefixes to express the values of dimensionless quantities that are much less—or even "greater"—than one. Common parts-per notations in terms of the uno are given in the table below. In 2004, a report to the International Co... | https://en.wikipedia.org/wiki?curid=145865 |
Parts-per notation ) and further, for those reports to state that the notations denote milligrams per liter or micrograms per liter. Although "2.1 mg/L" is not a dimensionless quantity, it is assumed in scientific circles that "2.1 mg/kg" (2.1 ppm) is the true measure because one liter of water has a mass of about one ... | https://en.wikipedia.org/wiki?curid=145865 |
Carbon-14 (C), or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. w... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 This resemblance is used in chemical and biological research, in a technique called carbon labeling: carbon-14 atoms can be used to replace nonradioactive carbon, in order to trace chemical and biochemical reactions involving carbon atoms from any given organic compound. goes through radioactive beta decay: B... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 Libby estimated that the radioactivity of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram of pure carbon, and this is still used as the activity of the "modern radiocarbon standard". In 1960, Libby was awarded the Nobel Prize in chemistry for this work. One of the frequent u... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 is produced in the upper layers of the troposphere and the stratosphere by thermal neutrons absorbed by nitrogen atoms. When cosmic rays enter the atmosphere, they undergo various transformations, including the production of neutrons. The resulting neutrons (n) participate in the following n-p reaction: The h... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 Local effects of cloud-ground discharge through sample residues are unclear, but possibly significant. can also be produced by other neutron reactions, including in particular C(n,γ)C and O(n,α)C with thermal neutrons, and N(n,d)C and O(n,He)C with fast neutrons. The most notable routes for C production by th... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 It is typically released to the atmosphere in the form of carbon dioxide at BWRs, and methane at PWRs. Best practice for nuclear power plant operator management of carbon-14 includes releasing it at night, when plants are not photosynthesizing. After production in the upper atmosphere, the carbon-14 atoms rea... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 CO--or rather, its relative absence—is therefore used to determine the relative contribution (or mixing ratio) of fossil fuel oxidation to the total carbon dioxide in a given region of the Earth's atmosphere. Dating a specific sample of fossilized carbonaceous material is more complicated. Such deposits often... | https://en.wikipedia.org/wiki?curid=146250 |
Carbon-14 94×10 was determined; probable reactions responsible for varied levels of C in different petroleum reservoirs, and the lower C levels in methane, have been discussed by Bonvicini et al. Since many sources of human food are ultimately derived from terrestrial plants, the relative concentration of carbon-14 in ... | https://en.wikipedia.org/wiki?curid=146250 |
Monolayer A monolayer is a single, closely packed layer of atoms, molecules, or cells. In some cases it is referred to as a self-assembled monolayer. Monolayers of layered crystals like graphene and molybdenum disulfide are generally called 2D materials. A Langmuir monolayer or insoluble monolayer is a one-molecule thi... | https://en.wikipedia.org/wiki?curid=146630 |
Monolayer It takes about 1 second for a surface to be covered at a pressure of 300 µPa (2×10 Torr). A Langmuir monolayer can be compressed or expanded by modifying its area with a moving barrier in a Langmuir film balance. If the surface tension of the interface is measured during the compression, a "compression isothe... | https://en.wikipedia.org/wiki?curid=146630 |
Monolayer A micelle is a monolayer, and the phospholipid lipid bilayer structure of biological membranes is technically two monolayers. Langmuir monolayers are commonly used to mimic cell membrane to study the effects of pharmaceuticals or toxins. In cell culture a monolayer refers to a layer of cells in which no cell ... | https://en.wikipedia.org/wiki?curid=146630 |
Vancomycin is an antibiotic used to treat a number of bacterial infections. It is recommended intravenously as a treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, and meningitis caused by methicillin-resistant "Staphylococcus aureus". Blood levels may be measure... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin is indicated for the treatment of serious, life-threatening infections by Gram-positive bacteria unresponsive to other antibiotics. The increasing emergence of vancomycin-resistant enterococci has resulted in the development of guidelines for use by the Centers for Disease Control Hospital Infection Control ... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin 1% of patients) include: anaphylaxis, toxic epidermal necrolysis, erythema multiforme, red man syndrome, superinfection, thrombocytopenia, neutropenia, leukopenia, tinnitus, dizziness and/or ototoxicity, and DRESS syndrome. can induce platelet-reactive antibodies in the patient, leading to severe thrombocyto... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin Prospective and retrospective studies attempting to evaluate the incidence of vancomycin-related nephrotoxicity have largely been methodologically flawed and have produced variable results. The most methodologically sound investigations indicate the actual incidence of vancomycin-induced nephrotoxicity is ar... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin Thus, whether therapeutic drug monitoring of vancomycin for the purpose of maintaining "therapeutic" levels will prevent ototoxicity also remains unproven. Another area of controversy and uncertainty concerns the question of whether, and if so, to what extent, vancomycin increases the toxicity of other nephr... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin is recommended to be administered in a dilute solution slowly, over at least 60 min (maximum rate of 10 mg/min for doses >500 mg) due to the high incidence of pain and thrombophlebitis and to avoid an infusion reaction known as the "red man syndrome" or "red neck syndrome". This syndrome, usually appearing w... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin Circumstances in which therapeutic drug monitoring is warranted include: patients receiving concomitant aminoglycoside therapy, patients with (potentially) altered pharmacokinetic parameters, patients on haemodialysis, patients administered high-dose or prolonged treatment, and patients with impaired renal f... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin Each module typically consists of an adenylation (A) domain, a peptidyl carrier protein (PCP) domain, and a condensation (C) or elongation domain. In the A domain, the specific amino acid is activated by converting into an aminoacyl adenylate enzyme complex attached to a 4'phosphopantetheine cofactor by thio... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin The three peptide syntheses are located at the start of the region of the bacterial genome linked with antibiotic biosynthesis, and span 27 kb. After the linear heptapeptide molecule is synthesized, vancomycin has to undergo further modifications, such as oxidative cross-linking and glycosylation, in trans b... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin exhibits atropisomerism — it has multiple chemically distinct rotamers owing to the rotational restriction of some of the bonds. The form present in the drug is the thermodynamically more stable conformer. acts by inhibiting proper cell wall synthesis in Gram-positive bacteria. Due to the different mechanism... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin delbruekii", which are sensitive. Other Gram-positive bacteria with intrinsic resistance to vancomycin include "Erysipelothrix rhusiopathiae", "Weissella confusa", and "Clostridium innocuum". Most Gram-negative bacteria are intrinsically resistant to vancomycin because their outer membranes are impermeable t... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin The -alanyl--lactate variation results in the loss of one hydrogen-bonding interaction (4, as opposed to 5 for -alanyl--alanine) possible between vancomycin and the peptide. This loss of just one point of interaction results in a 1000-fold decrease in affinity. The -alanyl--serine variation causes a six-fold... | https://en.wikipedia.org/wiki?curid=146773 |
Vancomycin The rapid development of penicillin resistance by staphylococci led to its being fast-tracked for approval by the Food and Drug Administration in 1958. Eli Lilly first marketed vancomycin hydrochloride under the trade name Vancocin never became the first-line treatment for "S. aureus" for several reasons: In... | https://en.wikipedia.org/wiki?curid=146773 |
Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia there is shivering and mental confusion. In moderate hypothermia shivering stops and confusion increases. In severe hypothermia, there may be paradoxical undressing, in which a person removes their... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Rewarming is typically continued until a person's temperature is greater than . If there is no improvement at this point or the blood potassium level is greater than 12 mmol/liter at any time, resuscitation may be discontinued. is the cause of at least 1,500 deaths a year in the United States. It is more co... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Signs and symptoms vary depending on the degree of hypothermia, and may be divided by the three stages of severity. Infants with hypothermia may feel cold when touched, with bright red skin and an unusual lack of energy. Symptoms of mild hypothermia may be vague, with sympathetic nervous system excitation (... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia There is often cold, inflamed skin, hallucinations, lack of reflexes, fixed dilated pupils, low blood pressure, pulmonary edema, and shivering is often absent. Pulse and respiration rates decrease significantly, but fast heart rates (ventricular tachycardia, atrial fibrillation) can also occur. Atrial fibri... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia It is often associated with paradoxical undressing. Researchers in Germany claim this is "obviously an autonomous process of the brain stem, which is triggered in the final state of hypothermia and produces a primitive and burrowing-like behavior of protection, as seen in hibernating animals". This happens ... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia In more rural environments, the incidence of hypothermia is higher among people with significant comorbidities and less able to move independently. With rising interest in wilderness exploration, and outdoor and water sports, the incidence of hypothermia secondary to accidental exposure may become more freq... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Some pensioners and disabled people are at risk because they do not work and cannot easily leave their homes. Better heat insulation can help. continues to be a major limitation to swimming or diving in cold water. The reduction in finger dexterity due to pain or numbness decreases general safety and work c... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia For example, plunged into freezing seas, around 20% of victims die within two minutes from cold shock (uncontrolled rapid breathing, and gasping, causing water inhalation, massive increase in blood pressure and cardiac strain leading to cardiac arrest, and panic); another 50% die within 15–30 minutes from c... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia In essence, hypothermia increases preglomerular vasoconstriction, thus decreasing both renal blood flow (RBF) and GFR. Accurate determination of core temperature often requires a special low temperature thermometer, as most clinical thermometers do not measure accurately below . A low temperature thermomete... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Some synthetic fabrics, such as polypropylene and polyester, are used in clothing designed to wick perspiration away from the body, such as liner socks and moisture-wicking undergarments. Clothing should be loose fitting, as tight clothing reduces the circulation of warm blood. In planning outdoor activity,... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Shelters can be of many different types, metal can conduct heat away from the occupants and is sometimes best avoided. The shelter should not be too big so body warmth stays near the occupants. Good ventilation is essential especially if a fire will be lit in the shelter. Fires should be put out before the ... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Intravenous thiamine and glucose is often recommended, as many causes of hypothermia are complicated by Wernicke's encephalopathy. The UK National Health Service advises against putting a person in a hot bath, massaging their arms and legs, using a heating pad, or giving them alcohol. These measures can cau... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia When severe hypothermia has led to cardiac arrest, effective extracorporeal warming results in survival with normal mental function about 50% of the time. Chest irrigation is recommended if bypass or ECMO is not possible. Rewarming shock (or rewarming collapse) is a sudden drop in blood pressure in combinat... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia It is not known if further defibrillation should be withheld until the core temperature reaches . In Europe, epinephrine is not recommended until the person's core temperature reaches , while the American Heart Association recommends up to three doses of epinephrine before a core temperature of is reached. ... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia In those who have hypothermia due to another underlying health problem, when death occurs it is frequently from that underlying health problem. Between 1995 and 2004 in the United States, an average of 1560 cold-related emergency department visits occurred per year and in the years 1999 to 2004, an average ... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia Civilian examples of deaths caused by hypothermia occurred during the sinkings of the RMS "Titanic" and RMS "Lusitania", and more recently of the MS "Estonia". Antarctic explorers developed hypothermia; Ernest Shackleton and his team measured body temperatures "below 94.2°, which spells death at home", thou... | https://en.wikipedia.org/wiki?curid=146879 |
Hypothermia The time limit for this technique, as also for accidental arrest in ice water (which internal temperatures may drop to as low as 15 °C), is about one hour. Many animals other than humans often induce hypothermia during hibernation or torpor. Water bears (Tardigrade), microscopic multicellular organisms, can... | https://en.wikipedia.org/wiki?curid=146879 |
Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are differen... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Some models such as the Preisach model (originally applied to ferromagnetism) and the Bouc–Wen model attempt to capture general features of hysteresis; and there are also phenomenological models for particular phenomena such as the Jiles–Atherton model for ferromagnetism. See also Hysteretic model. The term ... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis In the frequency domain, input and output are related by a complex "generalized susceptibility" that can be computed from formula_6; it is mathematically equivalent to a transfer function in linear filter theory and analogue signal processing. This kind of hysteresis is often referred to as "rate-dependent h... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis In control systems, hysteresis can be used to filter signals so that the output reacts less rapidly than it otherwise would, by taking recent history into account. For example, a thermostat controlling a heater may switch the heater on when the temperature drops below A, but not turn it off until the tempera... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Shortcuts are made between adjacent components (see crosstalk) and the hysteresis helps to keep the components in a particular state while the other components change states. Thus, all rows can be addressed at the same time instead of individually. In the field of audio electronics, a noise gate often implem... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Moving parts within machines, such as the components of a gear train, normally have a small gap between them, to allow movement and lubrication. As a consequence of this gap, any reversal in direction of a drive part will not be passed on immediately to the driven part. This unwanted delay is normally kept a... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis In terms of force, the rubber band was harder to stretch when it was being loaded than when it was being unloaded. In terms of time, when the band is unloaded, the effect (the length) lagged behind the cause (the force of the weights) because the length has not yet reached the value it had for the same weigh... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Small vehicle suspensions using rubber (or other elastomers) can achieve the dual function of springing and damping because rubber, unlike metal springs, has pronounced hysteresis and does not return all the absorbed compression energy on the rebound. Mountain bikes have made use of elastomer suspension, as ... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis When the maximum liquid volume is removed from the drop without the interfacial area decreasing the receding contact angle is thus measured. When volume is added to the maximum before the interfacial area increases, this is the advancing contact angle. As with the tilt method, the difference between the adva... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis The existence of the bubble shape hysteresis has important consequences in interfacial rheology experiments involving bubbles. As a result of the hysteresis, not all sizes of the bubbles can be formed on a capillary. Further the gas compressibility causing the hysteresis leads to unintended complications in ... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Adsorption hysteresis loops also have the unusual property that it is possible to scan within a hysteresis loop by reversing the direction of adsorption while on a point on the loop. The resulting scans are called "crossing," "converging," or "returning," depending on the shape of the isotherm at this point.... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis occurs because measured heat dissipation depends on sensor water content, and the sensor water content–matric potential relationship is hysteretic. , only desorption curves are usually measured during calibration of soil moisture sensors. Despite the fact that it can be a source of significant error, the sen... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis The width of the middle section is twice the coercivity of the material. A closer look at a magnetization curve generally reveals a series of small, random jumps in magnetization called Barkhausen jumps. This effect is due to crystallographic defects such as dislocations. Magnetic hysteresis loops are not ex... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Because the domains are not magnetized in the same direction, the magnetic moment per unit volume is smaller than it would be in a single-domain magnet; but domain walls involve rotation of only a small part of the magnetization, so it is much easier to change the magnetic moment. The magnetization can also ... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Electrical hysteresis typically occurs in ferroelectric material, where domains of polarization contribute to the total polarization. Polarization is the electrical dipole moment (either C·m or C·m). The mechanism, an organization of the polarization into domains, is similar to that of magnetic hysteresis. m... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Biochemical systems can also show hysteresis-like output when slowly varying states that are not directly monitored are involved, as in the case of the cell cycle arrest in yeast exposed to mating pheromone. Here, the duration of cell cycle arrest depends not only on the final level of input Fus3, but also o... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis The morphogen sonic hedgehog (Shh), for example, acts on limb bud and neural progenitors to induce expression of a set of homeodomain-containing transcription factors to subdivide these tissues into distinct domains. It has been shown that these tissues have a 'memory' of previous exposure to Shh. In neural ... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Since higher levels of active Ras have accumulated at the cell surface in T cells that have been previously stimulated by strong engagement of the T cell receptor, weaker subsequent T cell receptor signals received shortly afterwards will deliver the same level of activation due to the presence of higher lev... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis In utterances of vowel-voiceless consonant-vowel sequences during speech, the intraoral pressure is lower at the voice onset of the second vowel compared to the voice offset of the first vowel, the oral airflow is lower, the transglottal pressure is larger and the glottal width is smaller. is a commonly enco... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis According to theories based on hysteresis, severe economic downturns (recession) and/or persistent stagnation (slow demand growth, usually after a recession) cause unemployed individuals to lose their job skills (commonly developed on the job) or to find that their skills have become obsolete, or become demo... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis The existence of hysteresis has been put forward as a possible explanation for the persistently high unemployment of many economies in the 1990s. has been invoked by Olivier Blanchard among others to explain the differences in long run unemployment rates between Europe and the United States. Labor market ref... | https://en.wikipedia.org/wiki?curid=147003 |
Hysteresis Along with the classical loop, substitution of trapezoidal or triangular pulses instead of the harmonic functions allows piecewise-linear hysteresis loops frequently used in discrete automatics to be built in the model. There is an implementation of the hysteresis model in R programming language (package Hys... | https://en.wikipedia.org/wiki?curid=147003 |
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