Examinando por Materia "Integral de temperatura"

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  • Miniatura
    PublicaciónAcceso abierto
    A unified integral interpretation of thermal analysis data
    (Universidad del Valle, 2016-01-19) Carrero Mantilla, Javier Ignacio; Rojas González, Andres F.; Cárdenas Giraldo, J.M.
    (Eng) Most integral methods for thermal analysis data use linear regressions based on some approximate representation of the temperature integral. But this approach is inconvenient because there are many approximations and each one can produce a different result for the same data set. This work shows how to reduce the search of kinetic parameters to a non-linear regression calculating the temperature integral through the incomplete gamma function. In this way the use of approximations is avoided and dependence of the preexponential factor on temperature can be included in the model. An isoconversional analysis of a data set available in the literature is used to explain the proposed method.
  • Miniatura
    PublicaciónAcceso abierto
    Calculation of the temperature integ rals used in the processing of t he r mogravimetric analysis data
    (Universidad del Valle, 2019-07-31) Carrero, Javier Ignacio; Rojas, Andrés Felipe
    (Eng) There is no standard procedure for calculating the generalized temperature integral, instead myriads of different approximations to it are applied in the processing of thermogravimetric analysis data. This work presents first an integration procedure based on the Simpson rule that generates reference values of the generalized temperature integral. It also reviews the available representations of the temperature integral in power series, and presents the conversion of its generalized form into the form of sp ecial functions. From the comparison with the reference values from integration it was concluded that for argument values of practical interest the generalized temperature integral is best computed as the incomplete gamma function.