Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. Nuclear fission of heavy elements was discovered on Monday 19 December 1938 in Berlin, by German chemist Otto Hahn and his assistant Fritz Strassmann in cooperation with Austrian-Swedish physicist Lise Meitner. Hahn understood that a "burst" of the atomic nuclei had occurred. Meitner explained it theoretically in January 1939 along with her nephew Otto Robert Frisch. Frisch named the process by analogy with biological fission of living cells. In their second publication on nuclear fission in February of 1939, Hahn and Strassmann predicted the existence and liberation of additional neutrons during the fission process, opening up the possibility of a nuclear chain reaction. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Like nuclear fusion, for fission...

The tiger (Panthera tigris) is the largest living cat species and a member of the genus Panthera. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on ungulates, such as deer and wild boar. It is territorial and generally a solitary but social predator, requiring large contiguous areas of habitat to support its requirements for prey and rearing of its offspring. Tiger cubs stay with their mother for about two years and then become independent, leaving their mother's home range to establish their own. The tiger was first scientifically described in 1758. It once ranged widely from the Eastern Anatolia Region in the west to the Amur River basin in the east, and in the south from the foothills of the Himalayas to Bali in the Sunda Islands. Since the early 20th century, tiger populations have lost at least 93% of their historic range and have been extirpated from Western and Central Asia, the islands of Java and Bali, and in large areas of Southeast and South Asia and China. What remains of the range where tigers still roam free is fragmented...

Orto may refer to: Orto, Corse-du-Sud, a commune on the island of Corsica Orto (company), an Estonian publishing company

An old master print is a work of art produced by a printing process within the Western tradition. The term remains current in the art trade, and there is no easy alternative in English to distinguish the works of "fine art" produced in printmaking from the vast range of decorative, utilitarian and popular prints that grew rapidly alongside the artistic print from the 15th century onwards. Fifteenth-century prints are sufficiently rare that they are classed as old master prints even if they are of crude or merely workmanlike artistic quality. A date of about 1830 is usually taken as marking the end of the period whose prints are covered by this term. The main techniques used, in order of their introduction, are woodcut, engraving, etching, mezzotint and aquatint, although there are others. Different techniques are often combined in a single print. With rare exceptions printed on textiles, such as silk, or on vellum, old master prints are printed on paper. This article is concerned with the artistic, historical and social aspects of the subject; the article on printmaking summarizes the techniques used in making old master prints, from a modern perspective. Many...

The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between 0.5 and 10 keV. The composition of the solar wind plasma also includes a mixture of materials found in the solar plasma: trace amounts of heavy ions and atomic nuclei such as C, N, O, Ne, Mg, Si, S, and Fe. There are also rarer traces of some other nuclei and isotopes such as P, Ti, Cr, 54Fe and 56Fe, and 58Ni, 60Ni, and 62Ni. Superimposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field. The boundary separating the corona from the solar wind is called the Alfvén surface. At a distance of more than a few solar radii from the Sun, the solar wind...

Oogenesis, ovogenesis, or oögenesis is the differentiation of the ovum (egg cell) into a cell competent to further develop when fertilized. It is developed from the primary oocyte by maturation. Oogenesis is initiated in the embryonic stage. Oogenesis in non-human mammals In mammals, the first part of oogenesis starts in the germinal epithelium, which gives rise to the development of ovarian follicles, the functional unit of the ovary. Oogenesis consists of several sub-processes: oocytogenesis, ootidogenesis, and finally maturation to form an ovum (oogenesis proper). Folliculogenesis is a separate sub-process that accompanies and supports all three oogenetic sub-processes. Oogonium —(Oocytogenesis)—> Primary Oocyte —(Meiosis I)—> First Polar body (Discarded afterward) + Secondary oocyte —(Meiosis II)—> Second Polar Body (Discarded afterward) + Ovum Oocyte meiosis, important to all animal life cycles yet unlike all other instances of animal cell division, occurs completely without the aid of spindle-coordinating centrosomes. ...

Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies to solids and gases. An example in liquids is the miscibility of water and ethanol as they mix in all proportions.By contrast, substances are said to be immiscible if there are certain proportions in which the mixture does not form a solution. For one example, oil is not soluble in water, so these two solvents are immiscible. As another example, butanone (methyl ethyl ketone) is significantly soluble in water, but these two solvents are also immiscible because in some proportions the mixture will separate into two phases. Organic compounds In organic compounds, the weight percent of hydrocarbon chain often determines the compound's miscibility with water. For example, among the alcohols, ethanol has two carbon atoms and is miscible with water, whereas 1-butanol with four carbons is not. 1-Octanol, with eight carbons, is practically insoluble in water, and...

In sociology, anthropology, archaeology, history, philosophy, and linguistics, structuralism is a general theory of culture and methodology that implies that elements of human culture must be understood by way of their relationship to a broader system. It works to uncover the structures that underlie all the things that humans do, think, perceive, and feel. Alternatively, as summarized by philosopher Simon Blackburn, structuralism is:[T]he belief that phenomena of human life are not intelligible except through their interrelations. These relations constitute a structure, and behind local variations in the surface phenomena there are constant laws of abstract structure.Structuralism in Europe developed in the early 20th century, mainly in France and the Russian Empire, in the structural linguistics of Ferdinand de Saussure and the subsequent Prague, Moscow, and Copenhagen schools of linguistics. As an intellectual movement, structuralism became the heir to existentialism. After World War II, an array of scholars in the humanities borrowed Saussure's concepts for use in their respective fields. French anthropologist Claude Lévi...

The University of Paris (French: Université de Paris), known as the Sorbonne (French: [sɔʁbɔn]) metonymically, was the leading university in Paris, France, active from 1150 to 1970, except for 1793–1806 under the French Revolution. Emerging around 1150 as a corporation associated with the cathedral school of Notre Dame de Paris, it was considered the second-oldest university in Europe.Officially chartered in 1200 by King Philip II of France and recognised in 1215 by Pope Innocent III, it was later often nicknamed after its theological College of Sorbonne, founded by Robert de Sorbon and chartered by French King Saint Louis around 1257.Highly reputed internationally for its academic performance in the humanities ever since the Middle Ages – notably in theology and philosophy – it introduced several academic standards and traditions that have endured ever since and spread internationally, such as doctoral degrees and student nations. Vast numbers of popes, royalty, scientists, and intellectuals were educated at the University...

The AEW TNT Championship is a men's professional wrestling television championship created and promoted by the American promotion All Elite Wrestling (AEW). Established on March 30, 2020, it is named after the TNT television network, which currently airs AEW's secondary core program, Rampage, as well as the promotion's Battle of the Belts quarterly television specials. The inaugural champion was Cody Rhodes. The current champion is Powerhouse Hobbs, who is in his first reign. History In September 2019, a month before All Elite Wrestling (AEW) launched their first weekly television program, Dynamite, then-AEW Executive Vice President and wrestler Cody teased that the promotion would eventually debut a television championship, but their focus at that time was on their other recently established titles. In February 2020, wrestling journalist Dave Meltzer directly asked Cody on the possibility of the promotion adding a secondary championship. Although he did not confirm or deny it, Cody did not rule out the possibility of a secondary or "mid-card" title debuting that year. The following month on March 30 on AEW...