Viscosity and tracer diffusion coefficients, and thermodynamic properties, for ethanol + acetonitrile mixtures at 298.15 K

1983 ◽  
Vol 36 (4) ◽  
pp. 665 ◽  
Author(s):  
AJ Easteal

Molar volumes and partial molar volumes, tracer diffusion coefficients (D), and shear viscosities (η) are reported for ethanol + acetonitrile mixtures at 298.15 K. The tracer diffusion coefficients vary non-additively with composition, and the product Dη for each component is composition-dependent. Albright's equation for viscosity reproduces experimental viscosities to within the combined uncertainties of the experimental data. The system exhibits considerably less complex behaviour than does the analogous water + acetonitrile system, and the properties are thought to be dominated by dipole-dipole interactions between unlike molecules.

2007 ◽  
Vol 263 ◽  
pp. 141-146 ◽  
Author(s):  
Ü. Ugaste ◽  
Tony Laas ◽  
T. Škled-Gorbatšova

To prove the validity of Dayananda’s phenomenological model of interdiffusion in ternary systems the effective interdiffusion coefficients for a few diffusion couples in the system Cu-Ni-Fe, annealed at 1000 oC, are calculated on the basis of this model using available tracer diffusion and thermodynamic data. It is found that the calculated values of effective interdiffusion coefficients are in reasonable agreement with experimental values extracted independently from experimental concentration--penetration curves. Using the relationship between effective interdiffusion coefficients, tracer diffusion coefficients and thermodynamic factors, it is shown that thermodynamic properties of alloys play a significant role in interdiffusion processes in the system Cu-Fe-Ni.


2009 ◽  
Vol 283-286 ◽  
pp. 24-29 ◽  
Author(s):  
Elena V. Levchenko ◽  
Alexander V. Evteev ◽  
Irina V. Belova ◽  
Graeme E. Murch

. In this paper, carbon diffusion in cementite is studied by molecular dynamics simulation. An assumption that carbon-carbon interaction occurs only indirectly via neighbouring iron atoms is used. An interstitial mechanism of carbon diffusion in cementite is revealed. The principal tracer diffusion coefficients and activation parameters of carbon diffusion in cementite are calculated for the temperature range 1223-1373 K and compared with the available published experimental data.


1994 ◽  
Vol 369 ◽  
Author(s):  
Sanjeev Aggarwal ◽  
Rudiger Dieckmann

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.


Sign in / Sign up

Export Citation Format

Share Document