A new method that is simpler and more accurate than the author's previous method is presented for estimating f(E) and k 0 (E) in the distributed activation energy model. It utilizes at least three sets of experimental data obtained at different heating rates, a. The Arrhenius plot of ln(a/T 2 ) vs 1/T (T: temperature) at the same conversion level allows determination of both E and k 0 at that level by introducing an approximation. f(E) and k 0 (E), unique to the reaction system of concern, can then be obtained by changing the conversion level. The validity and accuracy of this new method are shown through model calculations. The method does not require a priori assumptions for f(E) and k 0 (E). The f(E) curves and the k 0 vs E relationships for the pyrolysis reactions of Argonne premium coals estimated by this method were successfully used to predict the weight loss curves at markedly different heating conditions.

Two types of self-gravitating particle solutions found in several theories with nonAbelian fields are smoothly connected by a family of non-trivial black holes. There exists a maximum point of the black hole entropy, where the stability of solutions changes. This criterion is universal, and the changes in stability follow from a catastrophe-theoretic analysis of the potential function defined by black hole entropy.

ABSTRACT:The isothermal phase diagram for poly(vinylidene fluoride)/dimethyl formamide/water system was derived. The binodal and spinodal were calculated based on the Flory-Huggins theory and the calculated binodal was approximately in agreement with the experimental data of the cloud points. The isothermal crystallization line was also obtained according to the theory of melting point depression. Mass transfer of the three components during membrane formation by the precipitation from the vapor phase has been analyzed. During this process, phase separation of the polymer solution is induced by the penetration of water vapor in the solution. The calculated result on the changes of the cast film weights indicated the good agreement with the experimental data. The time-course of the polymer concentration profile in the film was calculated for various cases of different humidity of the vapor phase and different initial polymer concentration.

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