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PC-SAFT
PC-SAFT (perturbed chain SAFT) is an equation of state that is based on statistical associating fluid theory (SAFT). Like other SAFT equations of state, it makes use of chain and association terms developed by Chapman, et al from perturbation theory.Chapman, Walter G., et al. "SAFT: Equation-of-state solution model for associating fluids." ''Fluid Phase Equilibria'' 52 (1989): 31-38. However, unlike earlier SAFT equations of state that used unbonded spherical particles as a reference fluid, it uses spherical particles in the context of hard chains as reference fluid for the dispersion term.Gross J, Sadowski G. Perturbed-chain SAFT: An equation of state based on a perturbation theory for chain molecules. Industrial & engineering chemistry research. 2001 Feb 21;40(4):1244-60. PC-SAFT was developed by Joachim Gross and Gabriele Sadowski, and was first presented in their 2001 article. Further research extended PC-SAFT for use with associating and polar molecules, and it has also been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistical Associating Fluid Theory
Statistical associating fluid theory (SAFT) is a chemical theory, based on perturbation theory, that uses statistical thermodynamics to explain how complex fluids and fluid mixtures form associations through hydrogen bonds. Widely used in industry and academia, it has become a standard approach for describing complex mixtures. Since it was first proposed in 1990, SAFT has been used in a large number of molecular-based equation of state models for describing the Helmholtz energy contribution due to association. Overview SAFT is a Helmholtz energy term that can be used in equations of state that describe the thermodynamic and phase equilibrium properties of pure fluids and fluid mixtures. SAFT was developed using statistical mechanics. SAFT models the Helmholtz free energy contribution due to association, i.e. hydrogen bonding. SAFT can be used in combination with other Helmholtz free energy terms. Other Helmholtz energy contributions consider for example Lennard-Jones interact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equation Of State
In physics and chemistry, an equation of state is a thermodynamic equation relating state variables, which describe the state of matter under a given set of physical conditions, such as pressure, volume, temperature, or internal energy. Most modern equations of state are formulated in the Helmholtz free energy. Equations of state are useful in describing the properties of pure substances and mixtures in liquids, gases, and solid states as well as the state of matter in the interior of stars. Though there are many equations of state, none accurately predicts properties of substances under all conditions. The quest for a universal equation of state has spanned three centuries. Overview At present, there is no single equation of state that accurately predicts the properties of all substances under all conditions. An example of an equation of state correlates densities of gases and liquids to temperatures and pressures, known as the ideal gas law, which is roughly accurate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation Theory
In mathematics and applied mathematics, perturbation theory comprises methods for finding an approximate solution to a problem, by starting from the exact solution of a related, simpler problem. A critical feature of the technique is a middle step that breaks the problem into "solvable" and "perturbative" parts. In regular perturbation theory, the solution is expressed as a power series in a small parameter The first term is the known solution to the solvable problem. Successive terms in the series at higher powers of \varepsilon usually become smaller. An approximate 'perturbation solution' is obtained by truncating the series, often keeping only the first two terms, the solution to the known problem and the 'first order' perturbation correction. Perturbation theory is used in a wide range of fields and reaches its most sophisticated and advanced forms in quantum field theory. Perturbation theory (quantum mechanics) describes the use of this method in quantum mechanics. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joachim Gross
Joachim was, according to Sacred tradition, the husband of Saint Anne, the father of Mary (mother of Jesus), and the maternal grandfather of Jesus. The story of Joachim and Anne first appears in the Gospel of James, part of the New Testament apocrypha. His feast day is 26 July, a date shared with Saint Anne. In Catholic tradition The story of Joachim, his wife Anne (or Anna), and the miraculous birth of their child Mary, the mother of Jesus, was told for the first time in the 2nd-century apocryphal infancy-gospel the Gospel of James (also called the ''Protoevangelium of James''). Joachim was a rich and pious man, who regularly gave to the poor; however, Charles Souvay, writing in the ''Catholic Encyclopedia'', says that the idea that Joachim possessed large herds and flocks is doubtful. At the temple, Joachim's sacrifice was rejected, as the couple's childlessness was interpreted as a sign of divine displeasure. Joachim consequently withdrew to the desert, where he fasted and did ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabriele Sadowski
Gabriele Sadowski (born 18 February 1964) is a German chemist. Early life and education Sadowski studied Chemistry at Technische Universität Leuna-Merseburg from 1982 to 1987. She finished her doctorate in 1991 at Technische Universität Leuna-Merseburg. She completed her dissertation at Technische Universität Berlin in 2000. Career and research Her research focuses on Polymer Thermodynamics, Thermodynamics of Pharmaceutical Systems, and Reaction Thermodynamics. Since 2001, she is full professor at TU Dortmund University. She took over the responsibility of prorector research in 2016. Awards and honours She was awarded the Gottfried Wilhelm Leibniz Prize in 2011 and she is a member of the North Rhine-Westphalian Academy of Sciences, Humanities and the Arts. See also * Timeline of women in science References {{DEFAULTSORT:Sadowski, Gabriele 1964 births Living people 21st-century German chemists German women chemists 21st-century German women scientists Technis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Residual Property (physics)
In thermodynamics a residual property is defined as the difference between a real fluid property and an ideal gas property, both considered at the same density, temperature, and composition, typically expressed as X(T, V, n) = X^(T, V, n) + X^(T, V, n) where X is some thermodynamic property at given temperature, volume and mole numbers, X^ is value of the property for an ideal gas, and X^ is the residual property. The reference state is typically incorporated into the ideal gas contribution to the value, as X^(T, V, n) = X^(T, n) + \Delta_ X (T, V, n) where X^ is the value of X at the reference state (commonly pure, ideal gas species at 1 bar), and \Delta_ X is the departure of the property for an ideal gas at (T, V, n) from this reference state. Residual properties should not be confused with excess properties, which are defined as the deviation of a thermodynamic property from some reference system, that is typically not an ideal gas system. Whereas excess properties and ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmholtz Free Energy
In thermodynamics, the Helmholtz free energy (or Helmholtz energy) is a thermodynamic potential that measures the useful work obtainable from a closed thermodynamic system at a constant temperature ( isothermal). The change in the Helmholtz energy during a process is equal to the maximum amount of work that the system can perform in a thermodynamic process in which temperature is held constant. At constant temperature, the Helmholtz free energy is minimized at equilibrium. In contrast, the Gibbs free energy or free enthalpy is most commonly used as a measure of thermodynamic potential (especially in chemistry) when it is convenient for applications that occur at constant ''pressure''. For example, in explosives research Helmholtz free energy is often used, since explosive reactions by their nature induce pressure changes. It is also frequently used to define fundamental equations of state of pure substances. The concept of free energy was developed by Hermann von Helmholtz, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole Fraction
In chemistry, the mole fraction or molar fraction, also called mole proportion or molar proportion, is a quantity defined as the ratio between the amount of a constituent substance, ''ni'' (expressed in unit of moles, symbol mol), and the total amount of all constituents in a mixture, ''n''tot (also expressed in moles): :x_i = \frac It is denoted ''xi'' (lowercase Roman letter '' x''), sometimes (lowercase Greek letter chi). (For mixtures of gases, the letter ''y'' is recommended.) It is a dimensionless quantity with dimension of \mathsf/\mathsf and dimensionless unit of moles per mole (mol/mol or molmol−1) or simply 1; metric prefixes may also be used (e.g., nmol/mol for 10−9). When expressed in percent, it is known as the mole percent or molar percentage (unit symbol %, sometimes "mol%", equivalent to cmol/mol for 10−2). The mole fraction is called amount fraction by the International Union of Pure and Applied Chemistry (IUPAC) and amount-of-substance fractio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman F
Norman or Normans may refer to: Ethnic and cultural identity * The Normans, a people partly descended from Norse Vikings who settled in the territory of Normandy in France in the 9th and 10th centuries ** People or things connected with the Norman conquest of southern Italy in the 11th and 12th centuries ** Normanist theory (also known as Normanism) and anti-Normanism, historical disagreement regarding the origin of Russia, Ukraine, Belarus and their historic predecessor, Kievan Rus' ** Norman dynasty, a series of monarchs in England and Normandy ** Norman architecture, romanesque architecture in England and elsewhere ** Norman language, spoken in Normandy ** People or things connected with the French region of Normandy Arts and entertainment * ''Norman'' (2010 film), a 2010 drama film * ''Norman'' (2016 film), a 2016 drama film * ''Norman'' (TV series), a 1970 British sitcom starring Norman Wisdom * ''The Normans'' (TV series), a documentary * "Norman" (song), a 1962 song w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boltzmann Constant
The Boltzmann constant ( or ) is the proportionality factor that relates the average relative thermal energy of particles in a ideal gas, gas with the thermodynamic temperature of the gas. It occurs in the definitions of the kelvin (K) and the molar gas constant, in Planck's law of black-body radiation and Boltzmann's entropy formula, and is used in calculating Johnson–Nyquist noise, thermal noise in resistors. The Boltzmann constant has Dimensional analysis, dimensions of energy divided by temperature, the same as entropy and heat capacity. It is named after the Austrian scientist Ludwig Boltzmann. As part of the 2019 revision of the SI, the Boltzmann constant is one of the seven "Physical constant, defining constants" that have been defined so as to have exact finite decimal values in SI units. They are used in various combinations to define the seven SI base units. The Boltzmann constant is defined to be exactly joules per kelvin, with the effect of defining the SI unit ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Distribution Function
In statistical mechanics, the radial distribution function, (or pair correlation function) g(r) in a system of particles (atoms, molecules, colloids, etc.), describes how density varies as a function of distance from a reference particle. If a given particle is taken to be at the origin ''O'', and if \rho = N/V is the average number density of particles, then the local time-averaged density at a distance r from ''O'' is \rho g(r). This simplified definition holds for a homogeneous and isotropic system. A more general case will be considered below. In simplest terms it is a measure of the probability of finding a particle at a distance of r away from a given reference particle, relative to that for an ideal gas. The general algorithm involves determining how many particles are within a distance of r and r+dr away from a particle. This general theme is depicted to the right, where the red particle is our reference particle, and the blue particles are those whose centers are with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avogadro Constant
The Avogadro constant, commonly denoted or , is an SI defining constant with an exact value of when expressed in reciprocal moles. It defines the ratio of the number of constituent particles to the amount of substance in a sample, where the particles in question are any designated elementary entity, such as molecules, atoms, ions, ion pairs. The numerical value of this constant is known as the Avogadro number, commonly denoted . The Avogadro ''number'' is an exact number equal to the number of constituent particles in one mole of any substance (by definition of the mole), historically derived from the experimental determination of the number of atoms in 12 grams of carbon-12 (12C) before the 2019 revision of the SI. Both the constant and the number are named after the Italian physicist and chemist Amedeo Avogadro. The Avogadro constant is used as a proportionality factor in relating the ''amount of substance'' , in a sample of a substance , to the corresponding n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
