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Loschmidt
Johann Josef Loschmidt (15 March 1821 – 8 July 1895), who referred to himself mostly as Josef Loschmidt (omitting his first name), was a notable Austrian scientist who performed ground-breaking work in chemistry, physics ( thermodynamics, optics, electrodynamics), and crystal forms. Born in Karlsbad, a town located in the Austrian Empire (now Karlovy Vary, Czech Republic), Loschmidt became professor of physical chemistry at the University of Vienna in 1868. He had two early mentors. The first was a Bohemian priest, Adalbert Czech, who persuaded Loschmidt's parents to send young Josef to high school in the Piarist monastery in Schlackenwerth and, in 1837, to advanced high-school classes in Prague. This was followed by two years of philosophy and mathematics at Prague's Charles University, where Loschmidt met his second important mentor. This was the philosophy professor Franz Serafin Exner, whose eyesight was failing, and who asked Loschmidt to be his personal reader ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loschmidt Constant
The ''Loschmidt constant'' or Loschmidt's number (symbol: ''n''0) is the number of particles (atoms or molecules) of an ideal gas in a given volume (the number density), and usually quoted at standard temperature and pressure. The 2014 CODATA recommended value is per cubic metre at 0 °C and 1 atm and the 2006 CODATA recommended value was 2.686 7774(47) per cubic metre at 0 °C and 1 atm. It is named after the Austrian physicist Johann Josef Loschmidt, who was the first to estimate the physical size of molecules in 1865. The term "Loschmidt constant" is also sometimes used to refer to the Avogadro constant, particularly in German texts. The Loschmidt constant is given by the relationship: :n_0 = \frac where ''p''0 is the pressure, ''k''B is the Boltzmann constant and ''T''0 is the thermodynamic temperature. It is related to the Avogadro constant, ''N''A, by: :n_0 = \frac where ''R'' is the gas constant. Being a measure of number density, the Los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loschmidt's Paradox
Loschmidt's paradox, also known as the reversibility paradox, irreversibility paradox or ', is the objection that it should not be possible to deduce an irreversible process from time-symmetric dynamics. This puts the time reversal symmetry of (almost) all known low-level fundamental physical processes at odds with any attempt to infer from them the second law of thermodynamics which describes the behaviour of macroscopic systems. Both of these are well-accepted principles in physics, with sound observational and theoretical support, yet they seem to be in conflict, hence the paradox. Origin Josef Loschmidt's criticism was provoked by the H-theorem of Boltzmann, which employed kinetic theory to explain the increase of entropy in an ideal gas from a non-equilibrium state, when the molecules of the gas are allowed to collide. In 1876, Loschmidt pointed out that if there is a motion of a system from time ''t''0 to time ''t''1 to time ''t''2 that leads to a steady decrease of ''H'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Law Of Thermodynamics
The second law of thermodynamics is a physical law based on universal experience concerning heat and energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects (or "downhill"), unless energy in some form is supplied to reverse the direction of heat flow. Another definition is: "Not all heat energy can be converted into work in a cyclic process."Young, H. D; Freedman, R. A. (2004). ''University Physics'', 11th edition. Pearson. p. 764. The second law of thermodynamics in other versions establishes the concept of entropy as a physical property of a thermodynamic system. It can be used to predict whether processes are forbidden despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics and provides necessary criteria for spontaneous processes. The second law may be formulated by the observation that the entropy of isolated systems left to spontaneous evolution cannot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Boltzmann
Ludwig Eduard Boltzmann (; 20 February 1844 – 5 September 1906) was an Austrian physicist and philosopher. His greatest achievements were the development of statistical mechanics, and the statistical explanation of the second law of thermodynamics. In 1877 he provided the current definition of entropy, S = k_ \ln \Omega \!, where Ω is the number of microstates whose energy equals the system's energy, interpreted as a measure of statistical disorder of a system. Max Planck named the constant the Boltzmann constant. Statistical mechanics is one of the pillars of modern physics. It describes how macroscopic observations (such as temperature and pressure) are related to microscopic parameters that fluctuate around an average. It connects thermodynamic quantities (such as heat capacity) to microscopic behavior, whereas, in classical thermodynamics, the only available option would be to measure and tabulate such quantities for various materials. Biography Childhood and educat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schlackenwerth
Ostrov (also called Ostrov nad Ohří; ; german: Schlackenwerth) is a town in Karlovy Vary District in the Karlovy Vary Region of the Czech Republic. It has about 16,000 inhabitants. The town centre is well preserved and is protected by law as an urban monument zone. Administrative parts Town parts and villages of Arnoldov, Dolní Žďár, Hanušov, Hluboký, Horní Žďár, Kfely, Květnová, Liticov, Maroltov, Mořičov and Vykmanov are administrative parts of Ostrov. Etymology The original name of the first settlement was ''Zlaukowerde'' (meaning "Slauko's island"), which changed into the German name ''Schlackenwerth''. In 1331, the name Ostrov (i.e. "island") was first used, in a charter of King John I of Bohemia. Geography Ostrov is located about northeast of Karlovy Vary. It lies at the confluence of the Bystřice River and Jáchymovský Creek, the Ohře flows just outside the territory. Most of the municipal territory lies in the Sokolov Basin, but it also extends to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karlovy Vary
Karlovy Vary (; german: Karlsbad, formerly also spelled ''Carlsbad'' in English) is a spa city in the Karlovy Vary Region of the Czech Republic. It has about 46,000 inhabitants. It lies on the confluence of the rivers Ohře and Teplá. It is named after Charles IV, Holy Roman Emperor and the King of Bohemia, who founded the city. Karlovy Vary is the site of numerous hot springs (13 main springs, about 300 smaller springs, and the warm-water Teplá River), and is the most visited spa town in the Czech Republic. The historic city centre with the spa cultural landscape is well preserved and is protected by law as an urban monument reservation. It is the largest spa complex in Europe. In 2021, the city became part of the transnational UNESCO World Heritage Site under the name " Great Spa Towns of Europe" because of its spas and architecture from the 18th through 20th centuries. Administrative parts Karlovy Vary is made up of 15 city parts and villages: *Karlovy Vary *Bohati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Vienna
The University of Vienna (german: Universität Wien) is a public research university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world. With its long and rich history, the university has developed into one of the largest universities in Europe, and also one of the most renowned, especially in the Humanities. It is associated with 21 Nobel prize winners and has been the academic home to many scholars of historical as well as of academic importance. History From the Middle Ages to the Enlightenment The university was founded on March 12, 1365, by Rudolf IV, Duke of Austria, hence the name "Alma Mater Rudolphina". After the Charles University in Prague and Jagiellonian University in Kraków, the University of Vienna is the third oldest university in Central Europe and the oldest university in the contemporary German-speaking world; it remains a question of definition as the Charles University ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Stefan
Josef Stefan ( sl, Jožef Štefan; 24 March 1835 – 7 January 1893) was an ethnic Carinthian Slovene physicist, mathematician, and poet of the Austrian Empire. Life and work Stefan was born in an outskirt village of St. Peter (Slovene: ; today a district of Klagenfurt) in the Austrian Empire (now in Austria) to father Aleš (Aleksander) Stefan, born in 1805, and mother Marija Startinik, born 1815. His parents, both ethnic Slovenes, married when Josef was eleven. The Stefans were a modest family. His father was a milling assistant and his mother served as a maidservant. Stefan's mother died in 1863 and his father in 1872. Josef was their only child. Stefan attended elementary school in Klagenfurt, where he showed his talent. They recommended to him to continue his schooling, so in 1845, he went to . As a thirteen-year-old boy, he experienced the revolutionary year of 1848, which inspired him to be sympathetic toward Slovene literary production. After having graduated top of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles University
) , image_name = Carolinum_Logo.svg , image_size = 200px , established = , type = Public, Ancient , budget = 8.9 billion CZK , rector = Milena Králíčková , faculty = 4,057 , administrative_staff = 4,026 , students = 51,438 , undergrad = 32,520 , postgrad = 9,288 , doctoral = 7,428 , city = Prague , country = Czech Republic , campus = Urban , colors = , affiliations = Coimbra Group EUA Europaeum , website = Charles University ( cs, Univerzita Karlova, UK; la, Universitas Carolina; german: Karls-Universität), also known as Charles University in Prague or historically as the University of Prague ( la, Universitas Pragensis, links=no), is the oldest and largest university in the Czech Republic. It is one of the oldest universities in Europe in continuous operation. Today, the university consists of 17 faculties located in Prague, Hradec Králové, and Plzeň. Charles University belongs among the top three universities in Central and Eastern Europe. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The Czech Republic has a hilly landscape that covers an area of with a mostly temperate continental and oceanic climate. The capital and largest city is Prague; other major cities and urban areas include Brno, Ostrava, Plzeň and Liberec. The Duchy of Bohemia was founded in the late 9th century under Great Moravia. It was formally recognized as an Imperial State of the Holy Roman Empire in 1002 and became a kingdom in 1198. Following the Battle of Mohács in 1526, the whole Crown of Bohemia was gradually integrated into the Habsburg monarchy. The Protestant Bohemian Revolt led to the Thirty Years' War. After the Battle of White Mountain, the Habsburgs consolidated their rule. With the dissolution of the Holy Empire in 1806, the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Temperature And Pressure
Standard temperature and pressure (STP) are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data. The most used standards are those of the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST), although these are not universally accepted standards. Other organizations have established a variety of alternative definitions for their standard reference conditions. In chemistry, IUPAC changed its definition of standard temperature and pressure in 1982: * Until 1982, STP was defined as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 1 atm (101.325 kPa). * Since 1982, STP has been defined as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 105 Pa (100 kPa, 1 bar). STP should not be confused with the standard stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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