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Abstract  

For complex heat capacity measurements, steady state of various types of temperature modulated DSC is theoretically investigated by a set of common comprehensive fundamental equations of heat balance. Heat capacities of heat paths, heat loss to the environment and mutual heat exchange between the sample and the reference material are taken into accounts together with thermal contact effect between the cell and its holder plate. Rigorous and general solutions have been obtained, and useful relations for complex heat capacity measurements have been derived for each type of DSC. They are compared with each other to elucidate unique features of each type of DSC.

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Abstract  

The example of the sequence of reactions

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $${\text{A}}\xrightarrow{{k_1 }}{\text{B}}\xrightarrow{{k_2 }}{\text{C}}$$ \end{document}
and the steady-state approximation are used to present a demonstration of the fact that the evolution of the reaction rates under non-isothermal conditions depends on the ratio of the activation energies and on the heating rate. At the same time, it is shown that, under isothermal conditions, the ratio of the activation energies plays no role.

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] Chapuis R. P. , Aubertin M. A simplified method to estimate saturated and unsaturated seepage through dikes under steady-state conditions , Canadian Geotechnical Journal , Vol. 38 , No. 6 , 2001 , pp. 1321

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The utilization, for programmed heating, of Fick's second equation concerning non-steady-state diffusion is discussed. Methods for calculating the activation energy of the diffusion process and the factorD 0 of the Arrhenius equation from a single non-isothermal experiment are suggested.

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Abstract  

Aqueous leaching of tritium from silica gel, loaded by absorption of water vapor, makes part of reactor de-commissioning. It is found to follow the formulation of steady-state diffusion.

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The paper deduces general relationships of real analytical functions for 1D quasi steady-state harmonic model of a conductor plate pair. To demonstrate the use of the model, the results are applied to calculate the active and reactive power of an induction furnace with graphite crucible and to determine the eddy current loss in different shielding arrangements.

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Abstract  

The authors continue their considerations concerning the validity of the steady-state approximation in non-isothermal kinetics. A sequence of two first-order consecutive reactions with an active intermediate was subjected to kinetic analysis by numerical solution of the corresponding differential kinetic equations for a number of particular cases. The results demonstrated that the rate of change of concentration of the active intermediate is negligibly small if the assumption made in the isothermal case is also accepted for the non-isothermal case, i.e. k 2(T(t))>> k 1(T(t)).

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The steady state solution of differential equations of periodical publication process is deduced, and based on this, the indicator of periodical publication delay, which reflects the degree of information ageing in editorial board of a periodical, is established. The indicator is proved to be the sum of two items: the pure publication delay, which reflects the editing rapidity of a periodical, and the ratio of deposited contribution quantity to the publishing quantity in one year, which reflects the waiting period of adopted papers deposited in editorial board. As a demonstration, the delay indicators of seven periodicals are calculated. Finally, the application of this indicator is discussed.

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Abstract  

Conventionally polymerisation of pyrrole is carried out either by chemical or electrochemical oxidation. In the present study polymerisation of pyrrole was carried out in a novel way in order to investigate the kinetics of the reactions involved. Carbonate radical (CO3 ) generated either radiolytically or photolytically from a sodium carbonate solution, was employed as the oxidant for the polymerisation reaction Flash photolysis and steady state ψ-radiolysis of pyrrole solution containing sodium carbonate was used for generating different intermediate and stable polymeric species. The kinetics of the formation and decay of different intermediate species were studied using UV-VIS spectrophotometry and the disappearances of the monomer was ascertained using HPLC. After analysing the species and steps involved a plausible mechanism for the polymerisation of pyrrole is suggested.

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