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In thermal engineering, the logarithmic mean temperature difference (LMTD) is used to determine the temperature driving force for heat transfer in flow systems, most notably in heat exchangers. The LMTD is a logarithmic average of the temperature difference between the hot and cold feeds at each end of the double pipe exchanger.
By adding a correction factor, known as the activity (, the activity of the i th component) to the liquid phase fraction of a liquid mixture, some of the effects of the real solution can be accounted for. The activity of a real chemical is a function of the thermodynamic state of the system, i.e. temperature and pressure.
This graph is called the "Van 't Hoff plot" and is widely used to estimate the enthalpy and entropy of a chemical reaction. From this plot, − Δ r H / R is the slope, and Δ r S / R is the intercept of the linear fit.
This would introduce a second correction factor λ B into λ R, giving = (). Experimental values for the "generalized" coefficient A G are generally of the order of magnitude of A 0 , but do differ significantly as between different emitting materials, and can differ as between different crystallographic faces of the same material.
A fudge factor is an ad hoc quantity or element introduced into a calculation, formula or model in order to make it fit observations or expectations. Also known as a correction coefficient , which is defined by
Chilton–Colburn J-factor analogy (also known as the modified Reynolds analogy [1]) is a successful and widely used analogy between heat, momentum, and mass transfer.The basic mechanisms and mathematics of heat, mass, and momentum transport are essentially the same.
where J is the emission current density, T is the temperature of the metal, W is the work function of the metal, k is the Boltzmann constant, q e is the Elementary charge, ε 0 is the vacuum permittivity, and A G is the product of a universal constant A 0 multiplied by a material-specific correction factor λ R which is typically of order 0.5.
The term is mainly used in coordination chemistry. The template effects emphasizes the pre-organization provided by the coordination sphere, although the coordination modifies the electronic properties (acidity, electrophilicity, etc.) of ligands. [1] An early example is the dialkylation of a nickel dithiolate: [2]