Effect of Experimental and Sample Factors on Dehydration Kinetics of Mildronate Dihydrate: Mechanism of Dehydration and Determination of Kinetic Parameters

2014 ◽  
Vol 103 (6) ◽  
pp. 1747-1755 ◽  
Author(s):  
Agris Bērziņš ◽  
Andris Actiņš



2021 ◽  
Author(s):  
Dario Balaban ◽  
◽  
Jelena Lubura ◽  
Predrag Kojić ◽  
Jelena Pavličević ◽  
...  

Rubber vulcanization is kinetically a complex process, since it consists of two simultaneous reactions: curing and degradation. To determine reaction kinetics, it is necessary to determine a kinetic model which describes the process adequately. Proposed kinetic model has six adjustable parameters. In order to determine kinetic parameters of the proposed kinetic model, commercially available rubber gum was used. Oscillating disc rheometer was used to investigate experimental dependence of torque on time, at six temperatures in the range from 130 to 180 °C, with a step of 10 °C. Matlab application, built via App Designer feature, was developed in order to fit the experimental data to the proposed kinetic model. Developed Matlab application, consisting of two tabs, enables user to upload raw rheometer data, perform manual fitting or automatic fitting (manual or automatic estimation of initial values of adjustable parameters), test the effect of constant values of some kinetic parameters on the overall quality of fit, visualize the dependence of kinetic parameters on temperature and to determine the values of Arrhenius expression for curing and degradation process. Both fitting methods were proven to be efficient; overall determination coefficient and MAPE value for automatic and manual fitting methods were >0.99 and <1%, and >0.999 and <1%, respectively. Arrhenius parameters were also determined with high accuracy (R2>0.98). Developed application enables simple and efficient determination of kinetic parameters by means of different fitting methods, simultaneous fitting of data on all temperatures, and testing the effect of constant kinetic parameters values on fitting results



2013 ◽  
Vol 67 (12) ◽  
Author(s):  
Juma Haydary ◽  
Dalibor Susa

AbstractKinetics of thermal decomposition of aseptic packages (e.g. Tetrapak cartons) and pyrolysis of this waste in a laboratory flow reactor was studied. Three different models for the calculation of the reaction rate and the determination of apparent kinetic parameters of thermal decomposition were used. The first method assumes a two stage thermal decomposition and the kinetic parameters were determined by fitting a derivative thermogravimetric (DTG) curve to experimentally determined thermogravimetric data of whole aseptic cartons. The second method uses kinetic parameters determined by fitting DTG curves to thermogravimetric data of individual components of aseptic packages. The last method was a multi-curve isoconversion method assuming a change of kinetic parameters with the increasing conversion. All types of the determined kinetic parameters were used in a mathematical model for thermal decomposition of mini briquettes made from aseptic packages at the temperature of 650°C. The model calculated also the heat conduction in the particles and it was verified by an independent set of experiments conducted in a laboratory screw type flow reactor.



1971 ◽  
Vol 44 (5) ◽  
pp. 1316-1325 ◽  
Author(s):  
R. B. Redding ◽  
D. A. Smith

Abstract Analysis of previously published cure data illustrates the importance of correct determination of the ultimate level of network chain density in the absence of reversion, and the correction of each kinetic data point for “reversion contributions”. A graphical procedure is described for the determination of kinetic parameters which takes these precautions into account.



1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S104-S121 ◽  
Author(s):  
E. E. Baulieu ◽  
J. P. Raynaud ◽  
E. Milgrom

ABSTRACT A brief review of the characteristics of steroid binding proteins found in the plasma and in some target organs is presented, followed by some general remarks on binding »specificity« and binding parameters. Useful techniques for measuring binding parameters at equilibrium are reported, both those which keep the equilibrium intact and those which implicate its disruption. A concept is developed according to which the determination of a specific steroid binding protein is based on the »differential dissociation« of the several steroid binding complexes present in most biological mixtures. Methods which allow determination of the kinetic parameters of the binding systems are also presented. Various representations of the binding and therefore different modes of graphic representation and calculation are discussed, including the recent »proportion graph« method.



2014 ◽  
pp. 228-231 ◽  
Author(s):  
Maciej Wojtczak ◽  
Aneta Antczak-Chrobot ◽  
Edyta Chmal-Fudali ◽  
Agnieszka Papiewska

The aim of the study is to evaluate the kinetics of the synthesis of dextran and other bacterial metabolites as markers of microbiological contamination of sugar beet.



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