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Thermodynamic data is usually presented as a table or chart of function values for one mole of a substance (or in the case of the steam tables, one kg). A thermodynamic datafile is a set of equation parameters from which the numerical data values can be calculated. Tables and datafiles are usually presented at a standard pressure of 1 bar or 1 ...
It may provide or confirm basic enthalpy data needed for the calculation of phase diagrams of metals, via CALPHAD or ab initio quantum chemistry methods. For a binary system composed by elements A and B, a generic Miedema Formula could be cast as Δ H = f ( E l e m e n t A , P h i A , n W S A , V A , E l e m e n t B .
The Dortmund Data Bank [1] (short DDB) is a factual data bank for thermodynamic and thermophysical data. Its main usage is the data supply for process simulation where experimental data are the basis for the design, analysis, synthesis, and optimization of chemical processes .
CALPHAD had a slow start in the 60s but sophisticated thermodynamic data bank systems started to appear in the 80s and today there are several commercial products on the market, e.g. FactSage, MTDATA, PANDAT, MatCalc, JMatPro, and Thermo-Calc as well as open-sources codes such as OpenCalphad, [8] PyCalphad, and ESPEI.
The easiest thermodynamic models, also known as equations of state, can come from simple correlations that relate different thermodynamic properties using a linear or second-order polynomial function of temperature and pressures. They are generally fitted using experimental data available for that specific properties.
The thermodynamic properties of materials are intensive thermodynamic parameters which are specific to a given material. Each is directly related to a second order differential of a thermodynamic potential. Examples for a simple 1-component system are: Compressibility (or its inverse, the bulk modulus) Isothermal compressibility
This is facilitated through the support of over 40 companies, and is particularly aided by the DDBST GmbH, which supplies the complete Dortmund Data Bank (DDB) and several software tools for free. The DDB, a factual data bank for thermodynamic data, especially phase equilibrium data, is the main source for the work of the consortium.
The laws of thermodynamics imply the following relations between these two heat capacities (Gaskell 2003:23): = = Here is the thermal expansion coefficient: = is the isothermal compressibility (the inverse of the bulk modulus):