The thermal degradation of various vinyl polyperoxides (poly(styrene peroxide) [PSP], poly(methyl methacrylate peroxide) [PMMAP], poly(a-methyl styrene peroxide) [PAMSP]) and their binary copolyperoxides (PSP-PAMSP [S...
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The thermal degradation of various vinyl polyperoxides (poly(styrene peroxide) [PSP], poly(methyl methacrylate peroxide) [PMMAP], poly(a-methyl styrene peroxide) [PAMSP]) and their binary copolyperoxides (PSP-PAMSP [SA], PSP-PMMAP [SM], PAMSP-PMMAP [AM]) were studied in a Thermogravimetric Analyzer (TGA). The thermal stability of the polyperoxides is in the order of PMMAP>SM>AM>SA>PSP>PAMSP. The addition of PAMSP to PSP showed a synergistic effect with higher thermal stability of the copolymer while the addition of PAMSP or PSP to PMMAP did not affect the thermal degradation of the copolymers. A method based on regression was proposed to determine the degradation parameters. The activation energies of degradation for the homopolyperoxides and copolyperoxides were determined by various methods and found in agreement with each other. (C) 2004 Elsevier Ltd. All rights reserved.
The subject of this paper is the neural network and linearregression as tools for the estimation of the component-property relationship of composite materials. Test data were used for the teaching of an ANN, verifyin...
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The subject of this paper is the neural network and linearregression as tools for the estimation of the component-property relationship of composite materials. Test data were used for the teaching of an ANN, verifying its output and computing a representation of the regression polynomial. Two kinds of expert systems have been built and tested for different sets of input and output characterizing the component and the properties of the material. Numerical experiments were conducted for real data given by a concrete factory. The linear regression method and the developed ANNs can be used for predicting material properties when the components are known as well as for the inverted problem. The expert systems were described and compared. (C) 2000 Elsevier Science B.V. All rights reserved.
According to the appearing of isosbestic point in the absorption spectra of Ho/Y-Tribromoarsenazo (TBA)systems,the complexation reaction is considered to be M+nL=ML_n.A method has been proposed based on it for calcula...
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According to the appearing of isosbestic point in the absorption spectra of Ho/Y-Tribromoarsenazo (TBA)systems,the complexation reaction is considered to be M+nL=ML_n.A method has been proposed based on it for calculating the mole fraction of free complexing agent in the solutions from spectral *** two linearregression formula have been introduced to determine the composition,the molar absorptivity,the conditional stability constant of the complex and the concentration of the complexing agent. This method has been used in Ho-TBA and Y-TBA ***^(3+)and Y^(3+)react with TBA and form 1: 2 complexes in HCl-NaAc buffer solution at pH *** molar absorptivities determined are 1.03×10~8 and 1.10×10~8 cm^2·mol^(-1),and the conditional stability constants(logβ_2)are 11.37 and 11.15 *** considering the pH effect in TBA complexing,their stability constants(log β_2^(ahs))are 43.23 and 43.01. *** new method is adaptable to such systems where the accurate concentration of the complexing agent can not be known conveniently.
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