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of Eq. 6 is called the temperature integral, which does not have an analytical solution. If it is assumed that x = E/RT , then reduces to ; where P( x ) is an infinite function of x . Hence, substituting the values of temperature

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Isoconversional analysis of solid-state transformations

A critical review. Part III. Isothermal and non isothermal predictions

Journal of Thermal Analysis and Calorimetry
Authors: J. Farjas and P. Roura

heating rate, and which is the temperature integral [ 18 ] (in Ref. [ 13 ] we provide some numerical recipes for calculating the temperature integral). Conventional isoconversional methods are known as integral methods because they are based on

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, L , Hen , Z , Cunxin , W . 2003 New temperature integral approximate formula for non-isothermal kinetic analysis . J Therm Anal Cal. 74 : 309 – 315 . 10.1023/A:1026310710529 . 26

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Non-isothermal model-free predictions

Application to the formation of yttria from yttrium trifluoroacetate

Journal of Thermal Analysis and Calorimetry
Authors: Hichem Eloussifi, Jordi Farjas, Pere Roura, and Mohamed Dammak

which a degree of transformation α j is reached when the sample is heated at the heating rate β i , and is the temperature integral [ 10 , 25 ]. Conversely, Roduit’s method delivers the degree of transformation once a time interval Δ t has elapsed

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Journal of Thermal Analysis and Calorimetry
Authors: Liang Xue, Feng-Qi Zhao, Xiao-Ling Xing, Zhi-Ming Zhou, Kai Wang, Hong-Xu Gao, Jian-Hua Yi, Si-Yu Xu, and Rong-Zu Hu

model function, and α is the conversion degree, a and b are coefficients. The combination of Eqs. 10 – 13 can give the following equation: 14 The limit of the temperature integral in Eq. 14 is from T e0 to T b . (1

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–Redfern approximation [ 14 , 15 ] of the temperature integral in Eq. 2 , which gives the following equations [ 16 ] 3 4 To obtain the kinetic parameters from Eq. 1 , f (α) functions were selected using the criteria proposed in [ 17 ]. Average

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uses the Coats–Redfern approximation of the temperature integral. The method is based on the measurement of temperatures for each conversion degree α and different heating rates β. The integral form of the KAS equation is, where A = Arrhenius

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decomposition step of the compound were estimated by the Capela-Ribeiro nonlinear isoconversional method, using fourth-order rotational approximation of the temperature integral [ 6 ]. For a given conversion α and a set of n experiments carried out at

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Journal of Thermal Analysis and Calorimetry
Authors: Hernani S. Barud, Clóvis A. Ribeiro, Jorge M. V. Capela, Marisa S. Crespi, Sidney. J. L. Ribeiro, and Younes Messadeq

were estimated by the Capela-Ribeiro non-linear isoconversional method, using 4th-order rotational approximation of the temperature integral [ 24 ]. For a given conversion α and a set of n experiments carried out at different heating rates β i ( i

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Journal of Thermal Analysis and Calorimetry
Authors: Adelia Emilia de Almeida, Ana Luiza Ribeiro Souza, Douglas Lopes Cassimiro, Maria Palmira Daflon Gremião, Clóvis Augusto Ribeiro, and Marisa Spirandeli Crespi

activation energy from dynamic data can be obtained from the Flynn–Wall–Ozawa isoconversional method [ 26 – 28 ], with Doyle’s approximation of p ( x ). The p(x) is defined by equation , temperature integral or integral of Arrhenius [ 29 ] which involves

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