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Paul Boucherot
Paul Boucherot (1869–1943) was an engineer with the Chemins de Fer du Nord (Northern Railway of France). He studied at the elite École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI) where he later also taught electrical engineering. He was a pioneer of AC electric power distribution, designed induction motors, and with Georges Claude, built early plants for obtaining thermal energy from the sea. He also contributed to electrical analysis, including the relationship between real and apparent power. Asynchronous motors Boucherot was interested in using polyphase supplies to power asynchronous motors as early as 1894. The squirrel-cage rotor asynchronous motor was invented by Mikhail Dolivo-Dobrovolsky in 1889 and they were being built industrially from 1891. A problem with asynchronous machines is that they are difficult to start. The coupling to the rotor is weak until it gets moving and the current drawn by the motor is high. Boucherot so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Père Lachaise Cemetery
Père Lachaise Cemetery (french: Cimetière du Père-Lachaise ; formerly , "East Cemetery") is the largest cemetery in Paris, France (). With more than 3.5 million visitors annually, it is the most visited necropolis in the world. Notable figures in the arts buried at Père Lachaise include Michel Ney, Frédéric Chopin, Émile Waldteufel, Édith Piaf, Marcel Proust, Georges Méliès, Marcel Marceau, Sarah Bernhardt, Oscar Wilde, Thierry Fortineau, J.R.D. Tata, Jim Morrison and Sir Richard Wallace. The Père Lachaise is located in the 20th arrondissement of Paris, 20th arrondissement and was the first garden cemetery, as well as the first municipal cemetery in Paris. It is also the site of three World War I memorials. The cemetery is located on the Boulevard de Ménilmontant. The Paris Métro station Philippe Auguste (Paris Métro), Philippe Auguste on Paris Métro Line 2, Line 2 is next to the main entrance, while the station Père Lachaise (Paris Métro), Père Lachaise, on both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zobel Network
: ''For the wave filter invented by Zobel and sometimes named after him see m-derived filters.'' Zobel networks are a type of filter section based on the image-impedance design principle. They are named after Otto Zobel of Bell Labs, who published a much-referenced paper on image filters in 1923. The distinguishing feature of Zobel networks is that the input impedance is fixed in the design independently of the transfer function. This characteristic is achieved at the expense of a much higher component count compared to other types of filter sections. The impedance would normally be specified to be constant and purely resistive. For this reason, Zobel networks are also known as constant resistance networks. However, any impedance achievable with discrete components is possible. Zobel networks were formerly widely used in telecommunications to flatten and widen the frequency response of copper land lines, producing a higher performance line from one originally intended for o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Academy Of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefront of scientific developments in Europe in the 17th and 18th centuries, and is one of the earliest Academy of Sciences, Academies of Sciences. Currently headed by Patrick Flandrin (President of the Academy), it is one of the five Academies of the Institut de France. History The Academy of Sciences traces its origin to Colbert's plan to create a general academy. He chose a small group of scholars who met on 22 December 1666 in the King's library, near the present-day Bibliothèque nationale de France, Bibliothèque Nationals, and thereafter held twice-weekly working meetings there in the two rooms assigned to the group. The first 30 years of the Academy's existence were relatively informal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Legion Of Honour
The National Order of the Legion of Honour (french: Ordre national de la Légion d'honneur), formerly the Royal Order of the Legion of Honour ('), is the highest French order of merit, both military and civil. Established in 1802 by Napoleon, Napoleon Bonaparte, it has been retained (with occasional slight alterations) by all later French governments and regimes. The order's motto is ' ("Honour and Fatherland"); its Seat (legal entity), seat is the Palais de la Légion d'Honneur next to the Musée d'Orsay, on the left bank of the Seine in Paris. The order is divided into five degrees of increasing distinction: ' (Knight), ' (Officer), ' (Commander (order), Commander), ' (Grand Officer) and ' (Grand Cross). History Consulate During the French Revolution, all of the French Order of chivalry, orders of chivalry were abolished and replaced with Weapons of Honour. It was the wish of Napoleon, Napoleon Bonaparte, the French Consulate, First Consul, to create a reward to commend c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signal-processing circuits. Since the invention of the first constant-potential transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutual Inductance
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called ''back EMF''. Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials. An electronic component designed to add inductance to a circuit is called an inductor. It typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morse Code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of the inventors of the telegraph. International Morse code encodes the 26 basic Latin letters through , one accented Latin letter (), the Arabic numerals, and a small set of punctuation and procedural signals ( prosigns). There is no distinction between upper and lower case letters. Each Morse code symbol is formed by a sequence of ''dits'' and ''dahs''. The ''dit'' duration is the basic unit of time measurement in Morse code transmission. The duration of a ''dah'' is three times the duration of a ''dit''. Each ''dit'' or ''dah'' within an encoded character is followed by a period of signal absence, called a ''space'', equal to the ''dit'' duration. The letters of a word are separated by a space of duration equal to three ''dits'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Field
An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field for a system of charged particles. Electric fields originate from electric charges and time-varying electric currents. Electric fields and magnetic fields are both manifestations of the electromagnetic field, one of the four fundamental interactions (also called forces) of nature. Electric fields are important in many areas of physics, and are exploited in electrical technology. In atomic physics and chemistry, for instance, the electric field is the attractive force holding the atomic nucleus and electrons together in atoms. It is also the force responsible for chemical bonding between atoms that result in molecules. The electric field is defined as a vector field that associates to each point in space the electrostatic ( Coulomb) for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georges Claude
Georges Claude (24 September 187023 May 1960) was a French engineer and inventor. He is noted for his early work on the industrial liquefaction of air, for the invention and commercialization of neon lighting, and for a large experiment on generating energy by pumping cold seawater up from the depths. He has been considered by some to be "the Edison of France". Claude was an active collaborator with the German occupiers of France during the Second World War, for which he was imprisoned in 1945 and stripped of his honors. Early life and career Georges Claude was born on 24 September 1870 in Paris, France, during the city's siege by German forces. Georges Claude studied at the École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI). He then held several positions. He was an electrical inspector in a cable factory and the laboratory manager in an electric works. He founded and edited a magazine, ''L'Étincelle Électrique'' (''The Electric Spark'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacques-Arsène D'Arsonval
Jacques-Arsène d'Arsonval (8 June 1851 – 31 December 1940) was a French physician, physicist and inventor of the moving-coil D'Arsonval galvanometer and the thermocouple ammeter. D'Arsonval was an important contributor to the emerging field of electrophysiology, the study of the effects of electricity on biological organisms, in the nineteenth century. Life D'Arsonval was born in the Château de la Borie, in La Porcherie, Haute Vienne, France. He studied medicine in Limoges and Paris and obtained his medical degree in 1877. From 1873 to 1878 he was assistant to Claude Bernard, one of the founders of experimental physiology. After Bernard’s death he assisted Charles-Edouard Brown-Séquard (1817-1894), giving his lectures, and when Brown-Séquard died in 1894 replaced him as professor at College de France. Influenced by Bernard, D'Arsonval decided to devote his life to research. In 1892, he became director of the new laboratory of biophysics at the College de France and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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