scholarly journals New Invariant Expressions in Chemical Kinetics

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 373 ◽  
Author(s):  
Gregory Yablonsky ◽  
Daniel Branco ◽  
Guy Marin ◽  
Denis Constales
Keyword(s):  
Chemical Kinetics ◽  
Equilibrium Constants ◽  
Mass Action ◽  
Single Experiment ◽  
Kinetic Coefficients ◽  
Mass Action Law

This paper presents a review of our original results obtained during the last decade. These results have been found theoretically for classical mass-action-law models of chemical kinetics and justified experimentally. In contrast with the traditional invariances, they relate to a special battery of kinetic experiments, not a single experiment. Two types of invariances are distinguished and described in detail: thermodynamic invariants, i.e., special combinations of kinetic dependences that yield the equilibrium constants, or simple functions of the equilibrium constants; and “mixed” kinetico-thermodynamic invariances, functions both of equilibrium constants and non-thermodynamic ratios of kinetic coefficients.

TOPOLOGICAL AND NONLINEAR PROPERTIES OF LIGAND-RECEPTOR SYSTEMS

1996 ◽  
Vol 04 (03) ◽  
pp. 315-352
Author(s):  
M. BOUNIAS ◽  
A. BONALY
Keyword(s):  
Equilibrium Constants ◽  
Reactive Species ◽  
Mass Action ◽  
Hill Coefficient ◽  
State Equations ◽  
Nonlinear Properties ◽  
Complex Processes ◽  
Mass Action Law ◽  
A Chain ◽  
Heterogeneous Phase

Ligand-receptor (L-R) interactions involving substrate-enzyme and hormone-receptor systems, obey complex processes. Many parameters are not easily addressed in classical kinetic approaches; most are generally based on the probabilistic mass-action law and equilibrium constants. We describe the system in terms of tessellation of the reactional space with balls B(x, Γ) centered on the reactive species and whose radius (Γ), used as a scaling unit, is derived from the Hausdorff distance η=dist(L, R). This value is altered by a set of corrective terms representing interactions with inert and non-reactive species present in the medium, the influence of particular cell factors including heterogeneous phase conditions, and metabolic dissipation of the product. Topological properties have been studied for nonlinear pairing function governing the distance between two species, and the fractal dimension of the system is linked with its Bouligand-Minkowski dimension. The set of instant state equations of the system includes a chain of transfer matrices accounting for the linear phase of catalytic functions. An alternative set of iterative functions providing a complete metric description of the system in its topological definition space, exhibits similarities with the equations of the Mandelbrot sets family. Experimental confirmation that the major parameters (Vmax, S50 and Hill coefficient) are polyphasic functions of time rather than constants was obtained for honeybees haemolymph α-glucosidases.

Ion exchange equilibria of arsenic in the presence of high sulphate and nitrate concentrations

2005 ◽  
Vol 5 (5) ◽  
pp. 67-74 ◽  
Author(s):  
R. Baciocchi ◽  
A. Chiavola ◽  
R. Gavasci
Keyword(s):  
Ion Exchange ◽  
Equilibrium Constants ◽  
Exchange Process ◽  
Quantitative Description ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Resin Phase ◽  
Ion Exchange Process ◽  
Mass Action Law ◽  
Anionic Resin

The aim of this work was to develop a quantitative description of the ion exchange equilibria of arsenic on a strong anionic resin, in the presence of nitrates and sulphates. First, the ion exchange equilibrium data of As(V) and NO3− on a strong anionic resin in chloride form were obtained and described with a model based on the mass action law. Namely, assuming ideal behaviour for both solution and resin phase, the thermodynamic constant of the As(V)/Cl− and NO3−/Cl− ion exchange equilibria were estimated by fitting of experimental data. Then, these equilibrium constants were used to predict the ion exchange behaviour of the ternary system As(V)/NO3−/Cl−, providing a rather good agreement with experimental results. The ion exchange equilibria involving sulphate ions were also studied, showing a very high affinity to the resin phase. This behaviour did not allow a quantitative robust modelling of the equilibrium pattern. The results discussed in this paper represent a first step toward the development of a comprehensive modelling of the ion exchange process for the removal of As(V) from surface and groundwater in the presence of competitive, naturally occurring anions.

Studies on Activator Formation in Human Plasma with Streptokinase

1973 ◽  
Vol 30 (02) ◽  
pp. 381-392
Author(s):  
M Martin ◽  
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Mass Action ◽  
Activator Concentration ◽  
Kinetic Effect ◽  
Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

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