Determination of cross-term diffusion coefficients in ternary systems by the capillary cell method

1974 ◽  
Vol 78 (22) ◽  
pp. 2281-2283 ◽  
Author(s):  
Kazuo Toukubo ◽  
Koichiro Nakanishi
Keyword(s):  
Diffusion Coefficients ◽  
Ternary Systems ◽  
Cross Term ◽  
Cell Method

Theory of the determination of diffusion coefficients by the one-compartment diafragm cell method

1977 ◽  
Vol 42 (9) ◽  
pp. 2595-2606 ◽  
Author(s):  
M. Šípek ◽  
I. Samohýl ◽  
J. Pick
Keyword(s):  
Diffusion Coefficients ◽  
Cell Method ◽  
The One

A spectroscopic method for determination of the cross-term diffusion coefficients in a three-component liquid system

1976 ◽  
Vol 36 (1) ◽  
pp. 391-396 ◽  
Author(s):  
M. D. Mikhailov ◽  
A. Z. Trifonov ◽  
I. A. Tsenov ◽  
M. A. Aladzhem
Keyword(s):  
Diffusion Coefficients ◽  
Spectroscopic Method ◽  
Liquid System ◽  
Cross Term ◽  
The Cross

scholarly journals Determination of Optimal Diffusion Coefficients in Lake Zirahuén through a Local Inverse Problem

Mathematics ◽  
2021 ◽  
Vol 9 (14) ◽  
pp. 1695
Author(s):  
Tzitlali Gasca-Ortiz ◽  
Francisco J. Domínguez-Mota ◽  
Diego A. Pantoja
Keyword(s):  
Inverse Problem ◽  
Diffusion Coefficients ◽  
Simple Technique ◽  
Diffusion Tensor ◽  
Cross Term ◽  
Release Experiment ◽  
Advection Diffusion Equation ◽  
Advection Diffusion ◽  
Dye Release

In this study, optimal diffusion coefficients for Lake Zirahuén, Mexico, were found under particular conditions based on images taken with a drone of a dye release experiment. First, the dye patch concentration was discretized using image processing tools, and it was then approximated by an ellipse, finding the optimal major and minor axes. The inverse problem was implemented by comparing these observational data with the concentration obtained numerically from the 2D advection–diffusion equation, varying the diffusion tensor. When the tensor was isotropic, values of K11=K22≈0.003 m2/s were found; when nonequal coefficients were considered, it was found that K11≈0.005 m2/s and K22≈0.002 m2/s, and the cross-term K12 influenced the results of the orientation of the ellipse. It is important to mention that, with this simple technique, the parameter estimation had consequences of great importance as the value for the diffusion coefficient was bounded significantly under particular conditions for this site of study.

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

Comments on determination of diffusion coefficients by chronoamperometry with unshielded planar stationary electrodes

1983 ◽  
Vol 55 (2) ◽  
pp. 382-383 ◽  
Author(s):  
Duane E. Weisshaar ◽  
Dennis E. Tallman
Keyword(s):  
Diffusion Coefficients

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

Infrared Quantitative Analysis of Mixtures Containing Isopropenyl Stearate, Stearic Acid, Stearic Anhydride, and Mixed Stearic—Acetic Anhydride

1972 ◽  
Vol 26 (1) ◽  
pp. 96-99 ◽  
Author(s):  
Mary Jo Calhoun ◽  
Edward S. DellaMonica
Keyword(s):  
Acetic Anhydride ◽  
Stearic Acid ◽  
Relative Concentration ◽  
Ternary Systems ◽  
Spectral Interference ◽  
Complex Mixtures ◽  
Ratio Method ◽  
Baseline Method ◽  
Binary And Ternary Systems

A method for the determination of individual components of complex mixtures is presented. The technique used is based on ir-absorbance measurements for stearic acid at 1700 and at 935 cm−1 when the concentration range exceeds 0.50% wt/vol; for isopropenyl stearate at 1145 and at 865 cm−1; for stearic anhydride at 1030 cm−1 and mixed stearic-acetic anhydride at 1000 cm−1. The baseline method was used in all absorbance measurements. Absorbance-concentration relationships obeyed Beer's law from 0 to 2.0% wt/vol for most compounds; the exception being stearic acid (at 1700 cm−1), where linearity was limited to a maximum 0.50% wt/vol. Due to spectral interference between the two anhydrides at low concentration ratios, an empirical percent transmission ratio method was used to estimate the relative concentration of each. Binary and ternary systems were studied and the standard deviations of the differences between theoretical and calculated values indicate that this method is reliable.

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