New models for tracer diffusion coefficients of hard sphere and real systems: Application to gases, liquids and supercritical fluids

2011 ◽  
Vol 55 (3) ◽  
pp. 898-923 ◽  
Author(s):  
Ana L. Magalhães ◽  
Francisco A. Da Silva ◽  
Carlos M. Silva
Keyword(s):  
Supercritical Fluids ◽  
Diffusion Coefficients ◽  
Hard Sphere ◽  
Tracer Diffusion ◽  
New Models ◽  
Tracer Diffusion Coefficients

scholarly journals Modelling the Diffusion Coefficients of Dilute Gaseous Solutes in Hydrocarbon Liquids

2021 ◽  
Vol 42 (10) ◽  
Author(s):  
Yasser A. Aljeshi ◽  
Malyanah Binti Mohd Taib ◽  
J. P. Martin Trusler
Keyword(s):  
Carbon Dioxide ◽  
Diffusion Coefficients ◽  
Hard Sphere ◽  
Tracer Diffusion ◽  
Pure Component ◽  
Viscosity Data ◽  
Polar Liquids ◽  
Self Diffusion ◽  
Coefficient Measurement ◽  
Tracer Diffusion Coefficients

AbstractIn this work, we present a model, based on rough hard-sphere theory, for the tracer diffusion coefficients of gaseous solutes in non-polar liquids. This work extends an earlier model developed specifically for carbon dioxide in hydrocarbon liquids and establishes a general correlation for gaseous solutes in non-polar liquids. The solutes considered were light hydrocarbons, carbon dioxide, nitrogen and argon, while the solvents were all hydrocarbon liquids. Application of the model requires knowledge of the temperature-dependent molar core volumes of the solute and solvent, which can be determined from pure-component viscosity data, and a temperature-independent roughness factor which can be determined from a single diffusion coefficient measurement in the system of interest. The new model was found to correlate the experimental data with an average absolute relative deviation of 2.7 %. The model also successfully represents computer-simulation data for tracer diffusion coefficients of hard-sphere mixtures and reduces to the expected form for self-diffusion when the solute and solvent become identical.

Non-Stoichiometry and Cation Tracer Diffusion Studies in the Magnetite-UlvÖSpinel Solution, (Fe,Ti)3-δO4

1994 ◽  
Vol 369 ◽  
Author(s):  
Sanjeev Aggarwal ◽  
Rudiger Dieckmann
Keyword(s):  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Oxygen Activity ◽  
Spinel Solid Solution ◽  
Low Oxygen ◽  
Cation Diffusion ◽  
Deviation From Stoichiometry ◽  
Diffusion Studies ◽  
Tracer Diffusion Coefficients ◽  
Point Defect Structure

AbstractCation diffusion in the spinel solid solution (Fe1-xTix)3-δO4 (0≤ x ≤ 0.3) was investigated at 1200 ºC as a function of oxygen activity, aO2 and cationic composition, x. At different cationic compositions, cation tracer diffusion coefficients, D*Me of Me = Fe and Ti were measured as a function of oxygen activity. Plots of log DMe vs. loga0 show V-shaped curves, indicating that different types of point defects prevail at high anc low oxygen activities. Thermogravimetric experiments were conducted, using a high resolution microbalance, to determine the deviation from stoichiometry in (Fe1-xTix)3-δO4 at 1200 °C. δversus log aO2 curves are S-shaped. An analysis of the oxygen activity dependences of thecation diffusion coefficients and the deviation from stoichiometry with regardto the point defect structure suggests that at high oxygen activities cation vacancies are the predominant defects governing the deviation from stoichiometry and the diffusion ofcations. At low oxygen activities, and at small values of x, cation interstitials determine the deviation from stoichiometry, while they dominate for 0 ≤ x ≤ 0.3 inthe cation diffusion.

Oxygen diffusion in amorphous and partially crystalline gallium oxide

2019 ◽  
Vol 21 (8) ◽  
pp. 4268-4275 ◽  
Author(s):  
Alexandra von der Heiden ◽  
Manuel Bornhöfft ◽  
Joachim Mayer ◽  
Manfred Martin
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficients ◽  
Low Temperatures ◽  
Oxygen Diffusion ◽  
Gallium Oxide ◽  
Tracer Diffusion ◽  
Tof Sims ◽  
Tracer Diffusion Coefficients ◽  
Oxygen Tracer

We established a TTT diagram of crystallisation of gallium oxide. Determination of oxygen tracer diffusion coefficients by IEDP/ToF-SIMS allowed us to access the activation energy for amorphous GaO1.5 at low temperatures.

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