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Julius Tafel
Julius Tafel (2 June 1862 – 2 September 1918) was a Swiss chemist and electrochemist. Work He worked first with Hermann Emil Fischer on the field of organic chemistry, but changed to electrochemistry after his work with Wilhelm Ostwald. He is known for the discovery of an electrosynthetic rearrangement reaction of various alkylated ethyl acetoacetate Acetoacetic acid (also acetoacetate and diacetic acid) is the organic compound with the formula CHCOCHCOOH. It is the simplest beta-keto acid, and like other members of this class, it is unstable. The methyl and ethyl esters, which are quite stab ...s to form hydrocarbons, now called the Tafel rearrangement, and the Tafel equation, which relates the rate of an electrochemical reaction to the overpotential. He is also credited for the discovery of the catalytic mechanism of hydrogen evolution (the Tafel mechanism). Tafel retired aged 48 due to ill health, but continued to write book reviews until his death. Life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courrendlin
Courrendlin (; fc, Coérrendlïn) is a municipality in the district of Delémont in the canton of Jura in Switzerland. On 1 January 2019 the former municipalities of Rebeuvelier and Vellerat merged into the municipality of Courrendlin. History Courrendlin is first mentioned in 866 as ''Rendelana Corte''. Geography Courrendlin has an area of . Of this area, or 43.2% is used for agricultural purposes, while or 39.7% is forested. Of the rest of the land, or 15.1% is settled (buildings or roads), or 0.9% is either rivers or lakes and or 0.6% is unproductive land.Swiss Federal Statistical Office-Land Use Statistics 2009 data accessed 25 March 2010 Of the built up area, industrial buildings made up 2.9% of the total area while housing and buildi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Group
In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula , derived from ethane (). ''Ethyl'' is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturated two-carbon moiety in a molecule, while the prefix "''eth-''" is used to indicate the presence of two carbon atoms in the molecule. Ethylation Ethylation is the formation of a compound by introduction of the ethyl group. The most widely practiced example of this reaction is the ethylation of benzene with ethylene to yield ethylbenzene, a precursor to styrene, which is a precursor to polystyrene. Approximately 24.7 million tons of ethylbenzene were produced in 1999. :: Many ethyl-containing compounds are generated by electrophilic ethylation, i.e. treatment of nucleophiles with sources of Et+. Triethyloxonium tetrafluoroborate t3OF4 is such a reagent. For good nucleophiles, less electrophilic reagents are employed, such as ethyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss Chemists
Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places *Swiss, Missouri *Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses *Swiss-system tournament, in various games and sports *Swiss International Air Lines **Swiss Global Air Lines, a subsidiary *Swissair, former national air line of Switzerland *.swiss alternative TLD for Switzerland See also *Swiss made, label for Swiss products *Swiss cheese (other) *Switzerland (other) *Languages of Switzerland, none of which are called "Swiss" *International Typographic Style, also known as Swiss Style, in graphic design *Schweizer (other), meaning Swiss in German *Schweitzer Schweitzer is a surname. Notable people with the surname include: * Albert Schweitzer, German theologian, musician, physician, and medical missionary, winner of the 1952 Nobel Peace Prize * Anton Schweitzer, opera composer * Brian Schweitzer, forme ..., a family name meaning Swiss in German * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1918 Suicides
This year is noted for the end of the First World War, on the eleventh hour of the eleventh day of the eleventh month, as well as for the Spanish flu pandemic that killed 50–100 million people worldwide. Events Below, the events of World War I have the "WWI" prefix. January * January – 1918 flu pandemic: The "Spanish flu" (influenza) is first observed in Haskell County, Kansas. * January 4 – The Finnish Declaration of Independence is recognized by Soviet Russia, Sweden, Germany and France. * January 9 – Battle of Bear Valley: U.S. troops engage Yaqui Native American warriors in a minor skirmish in Arizona, and one of the last battles of the American Indian Wars between the United States and Native Americans. * January 15 ** The keel of is laid in Britain, the first purpose-designed aircraft carrier to be laid down. ** The Red Army (The Workers and Peasants Red Army) is formed in the Russian SFSR and Soviet Union. * January 18 - The Historic Conce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1862 Births
Year 186 ( CLXXXVI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Aurelius and Glabrio (or, less frequently, year 939 ''Ab urbe condita''). The denomination 186 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Peasants in Gaul stage an anti-tax uprising under Maternus. * Roman governor Pertinax escapes an assassination attempt, by British usurpers. New Zealand * The Hatepe volcanic eruption extends Lake Taupō and makes skies red across the world. However, recent radiocarbon dating by R. Sparks has put the date at 233 AD ± 13 (95% confidence). Births * Ma Liang, Chinese official of the Shu Han state (d. 222) Deaths * April 21 – Apollonius the Apologist, Christian martyr * Bian Zhang, Chinese official and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebrew University Of Jerusalem
The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public university, public research university based in Jerusalem, Israel. Co-founded by Albert Einstein and Chaim Weizmann, Dr. Chaim Weizmann in July 1918, the public university officially opened in April 1925. It is the second-oldest Israeli university, having been founded 30 years before the Israeli Declaration of Independence, establishment of the State of Israel but six years after the older Technion university. The HUJI has three campuses in Jerusalem and one in Rehovot. The world's largest library for Jewish studies—the National Library of Israel—is located on its Edmond Safra, Edmond J. Safra campus in the Givat Ram neighbourhood of Jerusalem. The university has five affiliated teaching hospitals (including the Hadassah Medical Center), seven faculties, more than 100 research centers, and 315 academic departments. , one-third of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berichte Der Deutschen Chemischen Gesellschaft
''Chemische Berichte'' (usually abbreviated as ''Ber.'' or ''Chem. Ber.'') was a German-language scientific journal of all disciplines of chemistry founded in 1868. It was one of the oldest scientific journals in chemistry, until it merged with ''Recueil des Travaux Chimiques des Pays-Bas'' to form ''Chemische Berichte/Recueil'' in 1997. ''Chemische Berichte/Recueil'' was then merged with other European journals in 1998 to form ''European Journal of Inorganic Chemistry''. History Founded in 1868 as ''Berichte der Deutschen Chemischen Gesellschaft'' (, CODEN BDCGAS), it operated under this title until 1928 (Vol. 61). The journal was then split into: * ''Berichte der Deutschen Chemischen Gesellschaft, A: Vereins-Nachrichten'' (, CODEN BDCAAS), and * ''Berichte der Deutschen Chemischen Gesellschaft, B: Abhandlungen'' (, CODEN BDCBAD). Vol. 78 and 79 (1945–1946) were omitted and not published due to World War II. The journal was renamed ''Chemische Berichte'' (, CODEN CHBEAM) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Electrolysis
Electrolysis of water, also known as electrochemical water splitting, is the process of using electricity to decompose water into oxygen and hydrogen gas by electrolysis. Hydrogen gas released in this way can be used as hydrogen fuel, or remixed with the oxygen to create oxyhydrogen gas, which is used in welding and other applications. Electrolysis of water requires a minimum potential difference of 1.23 volts, though at that voltage external heat is required. E lectrolysis is rarely used in industrial applications since hydrogen can be produced less expensively from fossil fuels. History In 1789, Jan Rudolph Deiman and Adriaan Paets van Troostwijk used an electrostatic machine to make electricity that was discharged on gold electrodes in a Leyden jar with water. In 1800 Alessandro Volta invented the voltaic pile, and a few weeks later English scientists William Nicholson and Anthony Carlisle used it to electrolyse water. In 1806 Humphry Davy reported the results of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overpotential
In electrochemistry, overpotential is the potential difference (voltage) between a half-reaction's thermodynamically determined reduction potential and the potential at which the redox event is experimentally observed. The term is directly related to a cell's ''voltage efficiency''. In an electrolytic cell the existence of overpotential implies that the cell requires more energy than thermodynamically expected to drive a reaction. In a galvanic cell the existence of overpotential means less energy is recovered than thermodynamics predicts. In each case the extra/missing energy is lost as heat. The quantity of overpotential is specific to each cell design and varies across cells and operational conditions, even for the same reaction. Overpotential is experimentally determined by measuring the potential at which a given current density (typically small) is achieved. Thermodynamics The four possible polarities of overpotentials are listed below. * An electrolytic cell's anode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tafel Rearrangement
Electrosynthesis in chemistry is the synthesis of chemical compounds in an electrochemical cell. Compared to ordinary redox reaction, electrosynthesis sometimes offers improved selectivity and yields. Electrosynthesis is actively studied as a science and also has industrial applications. Electrooxidation has potential for wastewater treatment as well. Experimental setup The basic setup in electrosynthesis is a galvanic cell, a potentiostat and two electrodes. Typical solvent and electrolyte combinations minimizes electrical resistance. Protic conditions often use alcohol-water or dioxane-water solvent mixtures with an electrolyte such as a soluble salt, acid or base. Aprotic conditions often use an organic solvent such as acetonitrile or dichloromethane with electrolytes such as lithium perchlorate or tetrabutylammonium salts. The choice of electrodes with respect to their composition and surface area can be decisive. For example, in aqueous conditions the competing reactions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
