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Heinrich Lenz
Heinrich Friedrich Emil Lenz (; ; also Emil Khristianovich Lenz, russian: Эмилий Христианович Ленц; 12 February 1804 – 10 February 1865), usually cited as Emil Lenz or Heinrich Lenz in some countries, was a Russian physicist of Baltic German descent who is most noted for formulating Lenz's law in electrodynamics in 1834. Biography Lenz was born in Dorpat (nowadays Tartu, Estonia), at that time in the Governorate of Livonia in the Russian Empire. After completing his secondary education in 1820, Lenz studied chemistry and physics at the University of Dorpat. He traveled with the navigator Otto von Kotzebue on his third expedition around the world from 1823 to 1826. On the voyage Lenz studied climatic conditions and the physical properties of seawater. The results have been published in "Memoirs of the St. Petersburg Academy of Sciences" (1831). After the voyage, Lenz began working at the University of St. Petersburg, Russia, where he later served as the ...
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Tartu
Tartu is the second largest city in Estonia after the Northern European country's political and financial capital, Tallinn. Tartu has a population of 91,407 (as of 2021). It is southeast of Tallinn and 245 kilometres (152 miles) northeast of Riga, Latvia. Tartu lies on the Emajõgi river, which connects the two largest lakes in Estonia, Lake Võrtsjärv and Lake Peipus. From the 13th century until the end of the 19th century, Tartu was known in most of the world by variants of its historical name Dorpat. Tartu, the largest urban centre of southern Estonia, is often considered the "intellectual capital city" of the country, especially as it is home to the nation's oldest and most renowned university, the University of Tartu (founded in 1632). Tartu also houses the Supreme Court of Estonia, the Ministry of Education and Research, the Estonian National Museum, and the oldest Estonian-language theatre, Vanemuine. It is also the birthplace of the Estonian Song Festivals ...
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Rector (academia)
A rector (Latin for 'ruler') is a senior official in an educational institution, and can refer to an official in either a university or a secondary school. Outside the English-speaking world the rector is often the most senior official in a university, whilst in the United States the most senior official is often referred to as president and in the United Kingdom and Commonwealth of Nations the most senior official is the chancellor, whose office is primarily ceremonial and titular. The term and office of a rector can be referred to as a rectorate. The title is used widely in universities in EuropeEuropean nations where the word ''rector'' or a cognate thereof (''rektor'', ''recteur'', etc.) is used in referring to university administrators include Albania, Austria, the Benelux, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Germany, Greece, Hungary, Iceland, Italy, Latvia, Malta, Moldova, North Macedonia, Poland ...
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List Of Baltic Germans
This is a list of notable Baltic Germans. Art and literature Architects * Alfred Aschenkampff (1858–1914), architect (Latvia) * Paul Max Bertschy (1840–1911), city architect of Liepāja (Latvia) * Bernhard Bielenstein (1877–1959), architect (Latvia) * Wilhelm Bockslaff (1858–1945), architect (Latvia) *Johann Felsko (1813–1902), architect (Latvia) * Karl Felsko, (1844–1918), architect (Latvia) * Christoph Haberland (1750–1803), architect (Latvia) *Otto Pius Hippius (1826–1883), architect (Estonia) * Erich Jacoby (1885–1941), architect (Estonia) * Paul Mandelstamm (1872–1941), architect (Latvia) * Robert Natus (1890–1950), architect (Estonia) * Robert Pflug (1832–1885), architect (Latvia) *August Reinberg (1860–1908), architect (Latvia) *Jacques Rosenbaum (1878–1944), architect (Estonia) * Alfred Rosenberg (1893–1946), politician, Nazi ideologist and architect (Germany) *Max Scherwinsky (1859–1909), architect and designer (Latvia) * Edmund von Trom ...
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Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synod ...
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Lents (crater)
Lents is a small lunar impact crater on the far side of the Moon. It is located within the north-northwestern section of the immense skirt of ejecta that surrounds the Mare Orientale Mare Orientale (Latin ''orientāle'', the "eastern sea") is a lunar mare. It is located on the western border of the near side and far side of the Moon, and is difficult to see from an Earthbound perspective. Images from spacecraft have reveal ... impact basin. To the south is the Montes Cordillera mountain ring, and to the north-northeast is the damaged crater Elvey. This is a bowl-shaped formation with an interior floor that is about half the diameter of the crater. Attached to the northeastern exterior of Lents is the satellite crater Lents C, a feature of roughly the same dimension. Slightly more than a crater diameter to the east of Lents C is Pierazzo, which produced a broad, wispy ray system that extends for more than 100 km in all directions. The ray material from this impact l ...
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Galvanoplastic
Electrotyping (also galvanoplasty) is a chemical method for forming metal parts that exactly reproduce a model. The method was invented by Moritz von Jacobi in Russia in 1838, and was immediately adopted for applications in printing and several other fields. As described in an 1890 treatise, electrotyping produces "an exact facsimile of any object having an irregular surface, whether it be an engraved steel- or copper-plate, a wood-cut, or a form of set-up type, to be used for printing; or a medal, medallion, statue, bust, or even a natural object, for art purposes." In art, several important "bronze" sculptures created in the 19th century are actually electrotyped copper, and not bronze at all; sculptures were executed using electrotyping at least into the 1930s. In printing, electrotyping had become a standard method for producing plates for letterpress printing by the late 1800s. It complemented the older technology of stereotyping, which involved metal casting. By 1901, stere ...
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Electrotyping
Electrotyping (also galvanoplasty) is a chemical method for forming metal parts that exactly reproduce a model. The method was invented by Moritz von Jacobi in Russia in 1838, and was immediately adopted for applications in printing and several other fields. As described in an 1890 treatise, electrotyping produces "an exact facsimile of any object having an irregular surface, whether it be an engraved steel- or copper-plate, a wood-cut, or a form of set-up type, to be used for printing; or a medal, medallion, statue, bust, or even a natural object, for art purposes." In art, several important "bronze" sculptures created in the 19th century are actually electrotyped copper, and not bronze at all; sculptures were executed using electrotyping at least into the 1930s. In printing, electrotyping had become a standard method for producing plates for letterpress printing by the late 1800s. It complemented the older technology of stereotyping, which involved metal casting. By 1901, ste ...
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Medallion
A medal or medallion is a small portable artistic object, a thin disc, normally of metal, carrying a design, usually on both sides. They typically have a commemorative purpose of some kind, and many are presented as awards. They may be intended to be worn, suspended from clothing or jewellery in some way, although this has not always been the case. They may be struck like a coin by dies or die-cast in a mould. A medal may be awarded to a person or organisation as a form of recognition for sporting, military, scientific, cultural, academic, or various other achievements. Military awards and decorations are more precise terms for certain types of state decoration. Medals may also be created for sale to commemorate particular individuals or events, or as works of artistic expression in their own right. In the past, medals commissioned for an individual, typically with their portrait, were often used as a form of diplomatic or personal gift, with no sense of being an award for ...
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Moritz Von Jacobi
Moritz Hermann or Boris Semyonovich (von) Jacobi (russian: Борис Семёнович Якоби; 21 September 1801, Potsdam – 10 March 1874, Saint Petersburg) was a Prussian and Russian Imperial engineer and physicist of Jewish descent. Jacobi worked mainly in the Russian Empire. He furthered progress in galvanoplastics, electric motors, and wire telegraphy. Motors Born into an Ashkenazi Jewish family, Jacobi began to study magnetic motors in 1834. In 1835 moved to Dorpat (now Tartu, Estonia) to lecture at Dorpat University. He moved to Saint Petersburg in 1837 to research the usage of electromagnetic forces for moving machines at the Russian Academy of Sciences. He investigated the power of an electromagnet in motors and generators. While studying the transfer of power from a battery to an electric motor, he deduced the maximum power theorem. Jacobi tested the output of motors by determining the amount of zinc consumed by the battery. With the financial assistance of ...
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Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated; and the anode (positive electrode) is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion and corrosion, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts, or to manufacture metal plates with complex shape, a process called electroforming. It is used to deposit copper and other conductors in forming pr ...
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James Prescott Joule
James Prescott Joule (; 24 December 1818 11 October 1889) was an English physicist, mathematician and brewer, born in Salford, Lancashire. Joule studied the nature of heat, and discovered its relationship to mechanical work (see energy). This led to the law of conservation of energy, which in turn led to the development of the first law of thermodynamics. The SI derived unit of energy, the joule, is named after him. He worked with Lord Kelvin to develop an absolute thermodynamic temperature scale, which came to be called the Kelvin scale. Joule also made observations of magnetostriction, and he found the relationship between the current through a resistor and the heat dissipated, which is also called Joule's first law. His experiments about energy transformations were first published in 1843. Early years James Joule was born in 1818, the son of Benjamin Joule (1784–1858), a wealthy brewer, and his wife, Alice Prescott, on New Bailey Street in Salford. Joule was t ...
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Joule's First Law
Joule heating, also known as resistive, resistance, or Ohmic heating, is the process by which the passage of an electric current through a conductor produces heat. Joule's first law (also just Joule's law), also known in countries of former USSR as the Joule–Lenz law,Джоуля — Ленца закон
. ''Большая советская энциклопедия'', 3-е изд., гл. ред. А. М. Прохоров. Москва: Советская энциклопедия, 1972. Т. 8 ()
states that the of heating generated by an