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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 ...
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 .
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 activity of a real chemical is a function of the thermodynamic state of the system, i.e. temperature and pressure. Equipped with the activity coefficients and a knowledge of the constituents and their relative amounts, phenomena such as phase separation and vapour-liquid equilibria can be calculated. UNIFAC attempts to be a general model ...
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 .
A Assuming an altitude of 194 metres above mean sea level (the worldwide median altitude of human habitation), an indoor temperature of 23 °C, a dewpoint of 9 °C (40.85% relative humidity), and 760 mmHg sea level–corrected barometric pressure (molar water vapor content = 1.16%).
A robust thermodynamic model predicts the properties (such as VLE) close to the real experimental data. Cubic model development for mixtures of more than one component is different as, according to the Gibbs phase rule , at each temperature level of a multi-component system, equilibrium states can exist at multiple pressure levels.
Computational thermodynamics may be considered a part of materials informatics and is a cornerstone of the concepts behind the materials genome project. While crystallographic databases are used mainly as a reference source, thermodynamic databases represent one of the earliest examples of informatics, as these databases were integrated into thermochemical computations to map phase stability ...