Effect of Sorption-Desorption and Diffusion Processes on the Kinetics of Biodegradation of Organic Chemicals in Soil

2015 ◽  
pp. 73-114 ◽  
Author(s):  
Kate M. Scow
Keyword(s):  
Diffusion Processes ◽  
Organic Chemicals ◽  
Kinetics Of ◽  
And Diffusion

scholarly journals A NEW METHOD TO DISTINGUISH SEPARATE COMPONENTS IN CYTOCHEMICALLY STAINED MACROMOLECULES BY ANALYSIS OF THE KINETICS OF THE STAINING AND DESTAINING PROCESSES

1973 ◽  
Vol 21 (8) ◽  
pp. 723-728 ◽  
Author(s):  
W. A. L. DUIJNDAM ◽  
J. HERMANS ◽  
P. VAN DUIJN
Keyword(s):  
Time Course ◽  
Diffusion Processes ◽  
Reaction Scheme ◽  
New Method ◽  
Pseudo First Order Reaction ◽  
The Individual ◽  
Macromolecular Substance ◽  
Kinetics Of ◽  
And Diffusion ◽  
Reaction Schemes

A new method making it possible to analyze properties of the end products of cytochemical staining reactions in macromolecular substances not expressed in the absorption spectra is described. Mathematical analysis of the course of changes in the absorbance during staining or destaining of the macromolecular substance provides information about the reaction velocities of these processes for the individual components present as well as about the concentrations of the components thus detected. This analysis is performed by a procedure of computerized curve-fitting between experimentally determined and theoretically expected absorbance curves. The theoretical time course of absorbance is derived for a number of pseudo first-order reaction schemes, and a description is given of the way in which the most appropriate reaction scheme can be recognized and the parameters are estimated, both on the basis of the experimental absorbance curve. Possible complications due to dye impurities, depolymerization and diffusion processes are discussed.

The Reducibility of the Iron Ore Materials as Instrument of the Coke Consumption Decrease in the Blast Furnace Smelting

2013 ◽  
Vol 334-335 ◽  
pp. 375-380 ◽  
Author(s):  
A.N. Dmitriev ◽  
Yu.A. Chesnokov ◽  
Galina Yu. Vitkina
Keyword(s):  
Blast Furnace ◽  
Coke Consumption ◽  
Iron Ore ◽  
Diffusion Processes ◽  
Reduction Kinetics ◽  
Blast Furnace Smelting ◽  
Reduction Of Iron ◽  
Kinetics Of ◽  
And Diffusion ◽  
Furnace Smelting

The technique of defining the minimum coke consumption in blast furnace smelting allows for the calculation of the reserve of coke economy on the basis of thermodynamic principles. In this reserve the constitutive role belongs to the reducibility of the iron ore materials (the agglomerate and pellets). In the present paper, the questions of the reduction kinetics of the iron ore materials and diffusion processes at reduction of iron from its oxides are considered. It is shown that the reducibility of the iron ore materials is the basic reserve of economy the scarce and expensive coke in the blast furnace smelting.

Metamorphic reaction rate laws and development of isograds

1986 ◽  
Vol 50 (357) ◽  
pp. 359-373 ◽  
Author(s):  
Antonio C. Lasaga
Keyword(s):  
Diffusion Processes ◽  
Relative Role ◽  
Mineral Surfaces ◽  
Surface Kinetics ◽  
Rate Laws ◽  
Careful Treatment ◽  
Reaction Zones ◽  
Kinetics Of ◽  
And Diffusion

AbstractNew data on the kinetics of dehydration of muscovite + quartz suggest the necessity for a careful treatment of both surface kinetics and diffusion processes in metamorphic reactions. A new model is proposed that illustrates the relative role of diffusion and surface reactions in the overall metamorphic process. The rate law for the reaction at mineral surfaces derived from the experimental data is shown to be probably non-linear and similar to rate laws derived from Monte Carlo calculations. The experimental rate data is then used in a heat flow calculation to model the evolution of the muscovite isograd in the field. The position of the isograd, the temperature oversteps above equilibrium, and the width of ‘reaction zones’ are then analysed as a function of intrusion size and kinetic parameters.

Meridional Circulation, Turbulence, and Diffusion Processes in Stars

1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair
Keyword(s):  
Convection Zone ◽  
Diffusion Processes ◽  
Meridional Circulation ◽  
Diffusion Time ◽  
Work In Progress ◽  
First Results ◽  
Stellar Envelopes ◽  
And Diffusion ◽  
Turbulence And Diffusion ◽  
Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

NMR-Study of Structure and Diffusion Processes in Li3N

1980 ◽  
Vol 41 (C6) ◽  
pp. C6-28-C6-31 ◽  
Author(s):  
R. Messer ◽  
H. Birli ◽  
K. Differt
Keyword(s):  
Diffusion Processes ◽  
Nmr Study ◽  
And Diffusion

Effect of cluster-gradient architecture of nanostructured topocomposites on features of tribointeraction with heterophased material

2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Energy Dissipation ◽  
Phase Structure ◽  
Diffusion Processes ◽  
Structural Phase ◽  
High Wear Resistance ◽  
Wear Characteristics ◽  
And Diffusion

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.

Certain Problems with the Application of Stochastic Diffusion Processes for the Description of Chemical Engineering Phenomena. Diffusional Change of Solid Particle Size

1996 ◽  
Vol 61 (4) ◽  
pp. 536-563
Author(s):  
Vladimír Kudrna ◽  
Pavel Hasal
Keyword(s):  
Particle Size ◽  
Solid Particle ◽  
Chemical Engineering ◽  
Diffusion Processes ◽  
Granular Systems ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Diffusion Term ◽  
Population Balances ◽  
And Diffusion

To the description of changes of solid particle size in population, the application was proposed of stochastic differential equations and diffusion equations adequate to them making it possible to express the development of these populations in time. Particular relations were derived for some particle size distributions in flow and batch equipments. It was shown that it is expedient to complement the population balances often used for the description of granular systems by a "diffusion" term making it possible to express the effects of random influences in the growth process and/or particle diminution.

Kinetics of Equilibrium Passive Sampling of Organic Chemicals with Polymers in Diverse Mammalian Tissues

2021 ◽  
Author(s):  
Andreas Baumer ◽  
Sandra Jäsch ◽  
Nadin Ulrich ◽  
Ingo Bechmann ◽  
Julia Landmann ◽  
...  
Keyword(s):  
Passive Sampling ◽  
Organic Chemicals ◽  
Mammalian Tissues ◽  
Kinetics Of

scholarly journals Biosorption and Diffusion Modeling of Pb(II) by Malt Bagasse

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Klaiani B. Fontana ◽  
Giane Gonçalves Lenzi ◽  
Erica R. L. R. Watanabe ◽  
Ervin Kaminski Lenzi ◽  
Juliana A. M. T. Pietrobelli ◽  
...  
Keyword(s):  
Sorption Process ◽  
Isotherm Models ◽  
Diffusion Modeling ◽  
Biosorption Capacity ◽  
Kinetic And Thermodynamic Parameters ◽  
Pseudo Second Order ◽  
Ph Optimization ◽  
Kinetics Of ◽  
And Diffusion

The removal of Pb(II) from water by biosorption processes onto malt bagasse was investigated and the kinetic and thermodynamic parameters were obtained; additionally a diffusion modeling was proposed. The characterization of malt bagasse was performed by FTIR and SEM/EDS. The experiments were conducted in batch system and an experimental design based response surface methodology was applied for agitation speed and pH optimization. The kinetics of biosorption followed pseudo-second-order model and the temperature of the process affected the biosorption capacity. Isotherm models of Langmuir, Freundlich, and Elovich were applied and the Langmuir model showed better fit and the estimated biosorption capacity was 29.1 mg g−1. The negative values obtained for ΔG° and positive values of ΔH° confirm, respectively, the spontaneous and endothermic nature of the process. The diffusion modeling was performed based on experiments in the absence of agitation to investigate the influence of the biosorbent on the sorption process of Pb(II) ions.

scholarly journals Influence of Geometry on Thin Layer and Diffusion Processes at Carbon Electrodes

Langmuir ◽  
2021 ◽  
Author(s):  
Qun Cao ◽  
Zijun Shao ◽  
Dale K. Hensley ◽  
Nickolay V. Lavrik ◽  
B. Jill Venton
Keyword(s):  
Thin Layer ◽  
Diffusion Processes ◽  
Carbon Electrodes ◽  
And Diffusion
Sign in / Sign up

Export Citation Format

Share Document