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PV Magazine
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 hypothalamu ... [...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, strip clubs, 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. 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 residences 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. Pace's houses were initially rented out to a number of British servicemen who were stationed in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Vaginam
In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The vaginal introitus is normally partly covered by a thin layer of mucosal tissue called the hymen. The vagina allows for copulation and birth. It also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle. To accommodate smoother penetration of the vagina during sexual intercourse or other sexual activity, vaginal moisture increases during sexual arousal in human females and other female mammals. This increase in moisture provides vaginal lubrication, which reduces friction. The texture of the vaginal walls creates friction for the penis during sexual intercourse and stimulates it toward ejaculation, enabling fertilization. Along with pleasure and bonding, women's sexual behavior with other people can ... [...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 (mathematical analysis), branch of that Function (mathematics), function, so that it is Single-valued function, single-valued. A simple 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 . It is defined as the complex number such that :e^w = z. Now, for example, say we wish to find . This means we want to solve :e^w = i for w. The value i\pi/2 is a solution. However, there are other solutions, which is evidenced by considering the position of in the complex plane and in particular its argument (complex analysis), argument \arg i. We can rotate counterclockwise \pi/2 radians from 1 to reach initially, but if we rotate further another 2\pi we rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravirtualization
In computing, virtualization (abbreviated v12n) is a series of technologies that allows dividing of physical computing resources into a series of virtual machines, operating systems, processes or containers. Virtualization began in the 1960s with IBM CP/CMS. The control program CP provided each user with a simulated stand-alone System/360 computer. In hardware virtualization, the ''host machine'' is the machine that is used by the virtualization and the ''guest machine'' is the virtual machine. The words ''host'' and ''guest'' are used to distinguish the software that runs on the physical machine from the software that runs on the virtual machine. The software or firmware that creates a virtual machine on the host hardware is called a ''hypervisor'' or ''virtual machine monitor''. Hardware virtualization is not the same as hardware emulation. Hardware-assisted virtualization facilitates building a virtual machine monitor and allows guest OSes to be run in isolation. Desktop v ... [...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. Though semaphores are useful for preventing race conditions, they do not guarantee their absence. Semaphores that allow an arbitrary resource count are called counting semaphores, while semaphores that are ... [...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, 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 inte ... [...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 , known as the perovskite (structure), perovskite structure, which has a general chemical formula . 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 (geology), mantle, perovskite's occurrence at Khibiny Mountains, Khibina Massif is restricted to the silica under-saturat ... [...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 Unsaturated fat, 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 addition, 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 t ... [...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, specific parts of the molecules cannot survive the required reagents or chemical environments. These parts (functional groups) must be protected. For example, lithium aluminium hydride is a highly reactive reagent that usefully reduces esters to alcohols. It always reacts with carbonyl groups, and cannot be discouraged by any means. When an ester must be reduced in the presence of a carbonyl, hydride attack on the carbonyl must be prevented. One way to do so converts the carbonyl into an acetal, which does not react with hydrides. The acetal is then called a protecting group for the carbonyl. After the hydride step is complete, aqueous acid removes the acetal, restoring the carbonyl. This step ... [...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 respectively; 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 (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 ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrovalerone
(Centroton, 4-Methyl-β-keto-prolintane, Thymergix, O-2371) is a central nervous system (CNS) stimulant that acts as a norepinephrine–dopamine reuptake inhibitor (NDRI). It was developed in the 1980s and had briefly been approved in Spain and France for chronic fatigue or lethargy and as an appetite suppressant, but was withdrawn from both markets around 2001 due to safety concerns including problems with abuse and dependence. It is closely related on a structural level to a number of other cathinone stimulants, such as α-PVP, MDPV and prolintane. Side effects of pyrovalerone include decreased appetite, anxiety, fragmented sleep or insomnia, and trembling, shaking, or muscle tremors. Withdrawal symptoms following abuse upon discontinuation often results in depression. The ''R''-enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycythemia Vera
In oncology, polycythemia vera (PV) is an uncommon myeloproliferative neoplasm in which the bone marrow makes too many red blood cells. Approximately 98% of PV patients have a JAK2 gene mutation in their blood-forming cells (compared with 0.1-0.2% of the general population). Most of the health concerns associated with PV, such as thrombosis, are caused by the blood being Hemorheology, thicker as a result of the increased red blood cells. PV may be symptomatic or asymptomatic. Possible symptoms include itching (pruritus), particularly after exposure to warm water, and severe burning pain in the hands or feet that is usually accompanied by a Erythema, reddish or Cyanosis, bluish coloration of the skin. Treatment consists primarily of blood withdrawals (phlebotomy) and oral meds. PV is more common in the elderly. Signs and symptoms Symptoms People with PV can be asymptomatic. Symptoms of PVhttps://www.lls.org/myeloproliferative-neoplasms/polycythemia-vera/signs-and-symptoms t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
