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PV Diagram
PV may refer to: Places * Paceville, Malta * Puerto Vallarta, Mexico * Postal village, a settlement that has a post office United States * Palos Verdes Peninsula, California * Prescott Valley, Arizona * Prairie Village, Kansas Politics * Partido Verde (other), several political parties * Peoples Voice, a political party in Singapore * Preferential voting (other), a category of electoral systems Science and technology * Photovoltaics, a technology for converting sunlight into electricity * Potential vorticity, in fluid dynamics * Presta valve, one of the two common tire valves * Process variable, in control systems * Programmed visibility, of traffic signals Biology and medicine * Parvalbumin, a calcium-binding albumin protein * Pathovar, a bacterial strain or set of strains with the same or similar characteristics * Pemphigus vulgaris, a chronic blistering skin disease * '' Per vaginam'', through/via the vagina * Periventricular nucleus, of the hyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paceville
Paceville ( sometimes abbreviated PV) is a district in St Julian's which is the main nightlife hub in Malta, being heavily populated with nightclubs, bars, stripclubs, pubs and restaurants, it is hence also known as 'Malta's Sin City'. Paceville is located between Spinola Point and Dragonara Point, delimiting Spinola Bay and St. George's Bay respectively. Paceville is seen as a party destination in Europe and is a popular place for locals and tourists alike. In 2016, it was estimated that Paceville's population stood around 1,939, of which 1,160 were foreigners. Origins Early years Paceville traces its origins in the 1910s and 1920s when prominent lawyer and developer Dr Giuseppe Pace (1890–1971) built a few seaside residence in the area of St. Julian's known as 'il-Qaliet', the small bay between the Dragonara Peninsula and Portomaso. Some of these residencies are still there today, although they are now surrounded by the multi-storey apartments and hotels in the area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Vaginam
Per is a Latin preposition which means "through" or "for each", as in per capita. Per or PER may also refer to: Places * IOC country code for Peru * Pér, a village in Hungary * Chapman code for Perthshire, historic county in Scotland Math and statistics * Rate (mathematics), ratio between quantities in different units, described with the word "per" * Price–earnings ratio, in finance, a measure of growth in earnings * Player efficiency rating, a measure of basketball player performance * Partial equivalence relation, class of relations that are symmetric and transitive * Physics education research Science * Perseus (constellation), standard astronomical abbreviation * Period (gene) or ''per'' that regulates the biological clock and its corresponding protein PER * Protein efficiency ratio, of food * PER or peregrinibacteria, a candidate bacterial phylum Media and entertainment * PeR (band), a Latvian pop band * ''Per'' (film), a 1975 Danish film Transport * IATA co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Value
In mathematics, specifically complex analysis, the principal values of a multivalued function are the values along one chosen branch of that function, so that it is single-valued. The simplest case arises in taking the square root of a positive real number. For example, 4 has two square roots: 2 and −2; of these the positive root, 2, is considered the principal root and is denoted as \sqrt. Motivation Consider the complex logarithm function log ''z''. It is defined as the complex number ''w'' such that :e^w = z. Now, for example, say we wish to find log ''i''. This means we want to solve :e^w = i for ''w''. Clearly ''i''π/2 is a solution. But is it the only solution? Of course, there are other solutions, which is evidenced by considering the position of ''i'' in the complex plane and in particular its argument arg ''i''. We can rotate counterclockwise π/2 radians from 1 to reach ''i'' initially, but if we rotate further another 2π we reach ''i'' again. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravirtualization
In computing, paravirtualization or para-virtualization is a virtualization technique that presents a software interface to the virtual machines which is similar, yet not identical, to the underlying hardware–software interface. The intent of the modified interface is to reduce the portion of the guest's execution time spent performing operations which are substantially more difficult to run in a virtual environment compared to a non-virtualized environment. The paravirtualization provides specially defined 'hooks' to allow the guest(s) and host to request and acknowledge these tasks, which would otherwise be executed in the virtual domain (where execution performance is worse). A successful paravirtualized platform may allow the virtual machine monitor (VMM) to be simpler (by relocating execution of critical tasks from the virtual domain to the host domain), and/or reduce the overall performance degradation of machine execution inside the virtual guest. Paravirtualization re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type used to control access to a common resource by multiple threads and avoid critical section problems in a concurrent system such as a multitasking operating system. Semaphores are a type of synchronization primitive. A trivial semaphore is a plain variable that is changed (for example, incremented or decremented, or toggled) depending on programmer-defined conditions. A useful way to think of a semaphore as used in a real-world system is as a record of how many units of a particular resource are available, coupled with operations to adjust that record ''safely'' (i.e., to avoid race conditions) as units are acquired or become free, and, if necessary, wait until a unit of the resource becomes available. Semaphores are a useful tool in the prevention of race conditions; however, their use is not a guarantee that a program is free from these problems. Semaphores which allow an arbitrary resource count are c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Page View
In web analytics and website management, a pageview or page view, abbreviated in business to PV and occasionally called page impression, is a request to load a single HTML file ( web page) of an Internet site. On the World Wide Web, a page request would result from a web surfer clicking on a link on another page pointing to the page in question. In contrast, a hit refers to a request for any file from a web server. Therefore, there may be many hits per page view since an HTML page can contain multiple files such as images, videos, JavaScripts, CSS, cascading style sheets (CSS), etc. On balance, page views refer to a number of pages viewed or clicked on the site during the given time. Page views may be counted as part of web analytics. For the owner of the site, this information can be useful to see if any change in the "page" (such as the information or the way it is presented) results in more visits. If there are any advertisements on the page, the publishers would also be int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as (XIIA2+VIB4+X2−3), known as the perovskite structure. Many different cations can be embedded in this structure, allowing the development of diverse engineered materials. History The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite's notable crystal structure was first described by Victor Goldschmidt in 1926 in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Occurrence Found in the Earth's mantle, perovskite's occurrence at Khibina Massif is restricted to the silica under-saturated ultramafic rocks and foidolites, due to the instability in a paragen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxide Value
Detection of peroxide gives the initial evidence of rancidity in unsaturated fats and oils. Other methods are available, but peroxide value is the most widely used. It gives a measure of the extent to which an oil sample has undergone primary oxidation, extent of secondary oxidation may be determined from p-anisidine test.Chemistry And Technology Of Oils And FatChemistry And Technology Of Oils And Fats By Dr. M.M. Chakrabarty The double bonds found in fats and oils play a role in autoxidation. Oils with a high degree of unsaturation are most susceptible to autoxidation. The best test for autoxidation (oxidative rancidity) is determination of the peroxide value. Peroxides are intermediates in the autoxidation reaction. Autoxidation is a free radical reaction involving oxygen that leads to deterioration of fats and oils which form off-flavours and off-odours. Peroxide value, concentration of peroxide in an oil or fat, is useful for assessing the extent to which spoilage has advanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protecting Group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis. In many preparations of delicate organic compounds, some specific parts of their molecules cannot survive the required reagents or chemical environments. Then, these parts, or groups, must be protected. For example, lithium aluminium hydride is a highly reactive but useful reagent capable of reducing esters to alcohols. It will always react with carbonyl groups, and this cannot be discouraged by any means. When a reduction of an ester is required in the presence of a carbonyl, the attack of the hydride on the carbonyl has to be prevented. For example, the carbonyl is converted into an acetal, which does not react with hydrides. The acetal is then called a protecting group for the carbonyl. After the step involving the hydride is complete, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ideal Gas Equation
The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. The ideal gas law is often written in an empirical form: pV = nRT where p, V and T are the pressure, volume and temperature; n is the amount of substance; and R is the ideal gas constant. It can also be derived from the microscopic kinetic theory, as was achieved (apparently independently) by August Krönig in 1856 and Rudolf Clausius in 1857. Equation The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation relates these simply in two main forms. The temperature used in the equation of state is an absolute temperature: the appro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrovalerone
(Centroton, 4-Methyl-β-keto-prolintane, Thymergix, O-2371) is a psychoactive drug with stimulant effects via acting as a norepinephrine-dopamine reuptake inhibitor (NDRI), and is used for the clinical treatment of chronic fatigue or lethargy and as an anorectic or appetite suppressant for weight loss purposes. It was developed in the late 1960s and has since been used in France and several other European countries, and although pyrovalerone is still occasionally prescribed, it is used infrequently due to problems with abuse and dependence. It is closely related on a structural level to a number of other stimulants, such as α-PVP, MDPV and prolintane (Promotil, Katovit). Side effects of pyrovalerone include anorexia or loss of appetite, anxiety, fragmented sleep or insomnia, and trembling, shaking, or muscle tremors. Withdrawal following abuse upon discontinuation often results in depression. The ''R''-enantiomer of pyrovalerone is devoid of activity. See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycythemia Vera
Polycythemia vera is an uncommon myeloproliferative neoplasm (a type of chronic leukemia) in which the bone marrow makes too many red blood cells. It may also result in the overproduction of white blood cells and platelets. Most of the health concerns associated with polycythemia vera are caused by the blood being thicker as a result of the increased red blood cells. It is more common in the elderly and may be symptomatic or asymptomatic. Common signs and symptoms include itching (pruritus), and severe burning pain in the hands or feet that is usually accompanied by a reddish or bluish coloration of the skin. Patients with polycythemia vera are more likely to have gouty arthritis. Treatment consists primarily of phlebotomy. Signs and symptoms People with polycythemia vera can be asymptomatic. A classic symptom of polycythemia vera is pruritus or itching, particularly after exposure to warm water (such as when taking a bath), which may be due to abnormal histamine relea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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