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HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Euler–Mascheroni Constant
The Euler–Mascheroni constant (also called Euler's constant) is a mathematical constant recurring in analysis and number theory, usually denoted by the lowercase Greek letter gamma (γ). It is defined as the limiting difference between the harmonic series and the natural logarithm, denoted here by [math]\displaystyle{ \log: }[/math] Here, [math]\displaystyle{ \lfloor x\rfloor }[/math] represents the floor function. The numerical value of the Euler–Mascheroni constant, to 50 decimal places, is: 0.57721566490153286060651209008240243104215933593992... 
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  • 02 Dec 2022
Topic Review
Convection
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be transient (such as when a multiphase mixture of oil and water separates) or steady state (see Convection cell). The convection may be due to gravitational, electromagnetic or fictitious body forces. Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be identified by clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics. Convection is often categorised or described by the main effect causing the convective flow, e.g. Thermal convection. Convection cannot take place in most solids because neither bulk current flows nor significant diffusion of matter can take place.
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  • 02 Dec 2022
Topic Review
Guṇa
Guṇa (Sanskrit: गुण) is a concept in Hinduism and Sikhism, which can be translated as "quality, peculiarity, attribute, property". The concept is originally notable as a feature of Samkhya philosophy. The gunas are now a key concept in nearly all schools of Hindu philosophy. There are three gunas, according to this worldview, that have always been and continue to be present in all things and beings in the world. These three gunas are called: sattva (goodness, constructive, harmonious), rajas (passion, active, confused), and tamas (darkness, destructive, chaotic). All of these three gunas are present in everyone and everything, it is the proportion that is different, according to Hindu worldview. The interplay of these gunas defines the character of someone or something, of nature and determines the progress of life. In some contexts, it may mean "a subdivision, species, kind, quality", or an operational principle or tendency of something or someone. In human behavior studies, Guna means personality, innate nature and psychological attributes of an individual. Like all Sanskrit technical terms, guṇa can be difficult to summarize in a single word. Its original and common meaning is a thread, implying the original materials that weave together to make up reality. The usual, but approximate translation in common usage is "quality".
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  • 02 Dec 2022
Topic Review
Compartmental Models in Epidemiology
Compartmental models are a very general modelling technique. They are often applied to the mathematical modelling of infectious diseases. The population is assigned to compartments with labels – for example, S, I, or R, (Susceptible, Infectious, or Recovered). People may progress between compartments. The order of the labels usually shows the flow patterns between the compartments; for example SEIS means susceptible, exposed, infectious, then susceptible again. The origin of such models is the early 20th century, with important works being that of Ross in 1916, Ross and Hudson in 1917, Kermack and McKendrick in 1927 and Kendall in 1956 The models are most often run with ordinary differential equations (which are deterministic), but can also be used with a stochastic (random) framework, which is more realistic but much more complicated to analyze. Models try to predict things such as how a disease spreads, or the total number infected, or the duration of an epidemic, and to estimate various epidemiological parameters such as the reproductive number. Such models can show how different public health interventions may affect the outcome of the epidemic, e.g., what the most efficient technique is for issuing a limited number of vaccines in a given population.
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  • 02 Dec 2022
Topic Review
Primnoa
Primnoa (Lamororux, 1812) also known as red tree coral, is a genus of soft corals and the type genus of the family Primnoidae (Milne Edwards, 1857). They are sessile, benthic cnidarians that can be found in the North Pacific, North Atlantic, and Subantarctic South Pacific, and its members often play a vital ecological role as keystone species within their environment as a habitat and refuge for the megafauna that also inhabit those regions. This, in combination with their slow growth, makes the increasing disturbance to their habitats caused by fishing activities particularly impactful and difficult to recover from.
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  • 02 Dec 2022
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Radmilovac
Radmilovac (Serbian Cyrillic: Радмиловац) is a suburban settlement of Belgrade, the capital of Serbia, and an experimental farm of the University of Belgrade's Faculty of Agriculture. It is located in the Belgrade municipality of Grocka. It is also known for the hotel of the same name.
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  • 02 Dec 2022
Topic Review
Search Engine Manipulation Effect
The search engine manipulation effect (SEME) is the change in consumer preferences from manipulations of search results by search engine providers. SEME is one of the largest behavioral effects ever discovered. This includes voting preferences. A 2015 study indicated that such manipulations could shift the voting preferences of undecided voters by 20 percent or more and up to 80 percent in some demographics. The study estimated that this could change the outcome of upwards of 25 percent of national elections worldwide. On the other hand, Google denies secretly re-ranking search results to manipulate user sentiment, or tweaking ranking specially for elections or political candidates.
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  • 02 Dec 2022
Topic Review
Population Stratification
Population stratification (or population structure) is the presence of a systematic difference in allele frequencies between subpopulations in a population, possibly due to different ancestry, especially in the context of association studies.
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  • 02 Dec 2022
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The Shift Project
The Shift Project (also called The Shift or TSP) is a French nonprofit created in 2010 that aims to limit both climate change and the dependency of our economy on fossil fuels.
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  • 02 Dec 2022
Topic Review
Split-Single
The split-single (Doppelkolbenmotor to its German and Austrian manufacturers), is a variant on the two-stroke engine with two cylinders sharing a single combustion chamber.
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  • 02 Dec 2022
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