Calculation of diffusion coefficients at any temperature and pressure from a single measurement. I. Self diffusion

1980 ◽  
Vol 22 (6) ◽  
pp. 3130-3134 ◽  
Author(s):  
P. Varotsos ◽  
K. Alexopoulos
Keyword(s):  
Diffusion Coefficients ◽  
Single Measurement ◽  
Self Diffusion ◽  
Temperature And Pressure

scholarly journals Diffusion in periclase by combination of analytical formulas and thermodynamic model

2012 ◽  
Vol 12 (6) ◽  
pp. 1841-1844
Author(s):  
E. Dologlou
Keyword(s):  
Thermodynamic Model ◽  
Diffusion Coefficients ◽  
The Self ◽  
Single Measurement ◽  
Bulk Properties ◽  
Self Diffusion ◽  
Earth’S Mantle ◽  
Analytical Formulas ◽  
Range Of Values ◽  
Slight Discrepancy

Abstract. Analytical formulas for the temperature dependence of elastic constants of MgO combined with a thermodynamic model, which interconnects bulk properties to point defect parameters, can successfully reproduce the self diffusion coefficients of periclase at temperatures representative of the Earth's mantle conditions. Although the calculated diffusion coefficients are estimated from a single measurement and cover a broad range of values (i.e. five orders of magnitude), an almost excellent agreement with the experimental ones is observed. The slight discrepancy at the highest temperature lies at error margins.

scholarly journals Molecular dynamic simulation study of molten cesium

2017 ◽  
Vol 82 (6) ◽  
pp. 681-694 ◽  
Author(s):  
Saeid Yeganegi ◽  
Vahid Moeini ◽  
Zohreh Doroodi
Keyword(s):  
Internal Pressure ◽  
Diffusion Coefficients ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Coordination Numbers ◽  
Self Diffusion ◽  
Temperature And Pressure ◽  
Molecular Dynamic Simulation Study ◽  
Dynamics Simulations ◽  
And Diffusion

Molecular dynamics simulations were performed to study thermodynamics and structural properties of expanded caesium fluid. Internal pressure, radial distribution functions (RDFs), coordination numbers and diffusion coefficients have been calculated at temperature range 700?1600 K and pressure range 100?800 bar. We used the internal pressure to predict the metal?non-metal transition occurrence region. RDFs were calculated at wide ranges of temperature and pressure. The coordination numbers decrease and positions of the first peak of RDFs slightly increase as the temperature increases and pressure decreases. The calculated self-diffusion coefficients at various temperatures and pressures show no distinct boundary between Cs metallic fluid and its expanded fluid where it continuously increases with temperature.

Molecular Dynamics Study of the Effect of Pressure on an Aqueous NaCl Solution

1985 ◽  
Vol 40 (12) ◽  
pp. 1235-1247 ◽  
Author(s):  
G. Jancsó ◽  
K. Heinzinger ◽  
P. Bopp
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Bulk Water ◽  
Force Model ◽  
Nacl Solution ◽  
Self Diffusion ◽  
Dynamical Properties ◽  
Temperature And Pressure ◽  
Dynamics Simulations

Molecular dynamics simulations of a 2.2 molal NaCI solution at room temperature and pressure of 1 bar and 10 kbar have been performed employing a modified version of the central-force model of water. The changes in the structural and dynamical properties of the solution resulting from the increase in pressure are reported. The effect of ions on the self-diffusion coefficients of hydration and bulk water and on the IR spectroscopical properties of the solution is also discussed and compared with the available experimental data.

scholarly journals Theoretical Modelling of Ion Exchange Processes in Glass: Advances and Challenges

2021 ◽  
Vol 11 (11) ◽  
pp. 5070
Author(s):  
Xesús Prieto-Blanco ◽  
Carlos Montero-Orille
Keyword(s):  
Ion Exchange ◽  
Diffusion Coefficients ◽  
Molten Salts ◽  
Theoretical Modelling ◽  
Copper Films ◽  
Theoretical Frameworks ◽  
Self Diffusion ◽  
Exchange Processes ◽  
The One ◽  
Made In

In the last few years, some advances have been made in the theoretical modelling of ion exchange processes in glass. On the one hand, the equations that describe the evolution of the cation concentration were rewritten in a more rigorous manner. This was made into two theoretical frameworks. In the first one, the self-diffusion coefficients were assumed to be constant, whereas, in the second one, a more realistic cation behaviour was considered by taking into account the so-called mixed ion effect. Along with these equations, the boundary conditions for the usual ion exchange processes from molten salts, silver and copper films and metallic cathodes were accordingly established. On the other hand, the modelling of some ion exchange processes that have attracted a great deal of attention in recent years, including glass poling, electro-diffusion of multivalent metals and the formation/dissolution of silver nanoparticles, has been addressed. In such processes, the usual approximations that are made in ion exchange modelling are not always valid. An overview of the progress made and the remaining challenges in the modelling of these unique processes is provided at the end of this review.

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