Inert gases in type A zeolites. 2. Henry constants and diffusion coefficients at low degree of filling

1978 ◽  
Vol 27 (2) ◽  
pp. 244-250 ◽  
Author(s):  
V. A. Bakaev ◽  
L. F. Smirnova
Keyword(s):  
Diffusion Coefficients ◽  
Type A ◽  
Inert Gases ◽  
Low Degree ◽  
Henry Constants ◽  
And Diffusion ◽  
Degree Of Filling

Sorption of the Inert Gases (Ar, Kr, and Xe) in Type A Zeolites

1975 ◽  
Vol 53 (7) ◽  
pp. 996-1006 ◽  
Author(s):  
Russell Ian Derrah ◽  
Douglas Morris Ruthven
Keyword(s):  
Low Temperatures ◽  
Equilibrium Constants ◽  
Type A ◽  
Inert Gases ◽  
Henry's Law ◽  
Equilibrium Isotherms ◽  
Adsorbed Phase ◽  
5A Zeolite ◽  
Experimental Values ◽  
Henry Constants

Theoretical potential profiles for Ar, Kr, and Xe occluded in an idealized 5A zeolite are calculated and used to evaluate the Henry's law equilibrium constants for these species. Calculations were made using the three common formulae to estimate the dispersion constants (Kirkwood–Mueller, Slater–Kirkwood, and London) and the theoretical Henry constants are compared with the values obtained directly from experimental equilibrium isotherms. For both Kr and Xe the Slater–Kirkwood formula gives the best agreement with the experimental values while, for argon, the London formula is best. At higher concentrations the isotherms for Kr can be well represented by a simple Langmuir expression with eleven sites per cavity while for Xe there appears to be a transition from localized sorption at low temperatures to a mobile adsorbed phase at higher temperatures. These conclusions are qualitatively consistent with the results of the theoretical potential calculations.

PREDICTION OF THE TRANSPORT PROPERTIES OF SF6 WITH O2, CO2, CF4, N2 AND CH4 MIXTURES AT LOW DENSITY BY THE INVERSION METHOD (PART II)

2004 ◽  
Vol 03 (01) ◽  
pp. 69-90 ◽  
Author(s):  
BEHZAD HAGHIGHI ◽  
ALIREZA HASSANI DJAVANMARDI ◽  
MOHAMAD MEHDI PAPARI ◽  
MOHSEN NAJAFI
Keyword(s):  
Potential Energy ◽  
Diffusion Coefficients ◽  
Potential Energy Function ◽  
Model Potential ◽  
Inversion Method ◽  
Low Density ◽  
Initial Model ◽  
Lennard Jones ◽  
Inversion Procedure ◽  
And Diffusion

Viscosity and diffusion coefficients for five equimolar binary gas mixtures of SF 6 with O 2, CO 2, CF 4, N 2 and CH 4 gases are determined from the extended principle of corresponding states of viscosity by the inversion technique. The Lennard–Jones 12-6 (LJ 12-6) potential energy function is used as the initial model potential required by the technique. The obtained interaction potential energies from the inversion procedure reproduce viscosity within 1% and diffusion coefficients within 5%.

scholarly journals Boundary behavior and product-form stationary distributions of jump diffusions in the orthant with state-dependent reflections

2008 ◽  
Vol 40 (02) ◽  
pp. 529-547
Author(s):  
Francisco J. Piera ◽  
Ravi R. Mazumdar ◽  
Fabrice M. Guillemin
Keyword(s):  
Random Fields ◽  
Diffusion Coefficients ◽  
Boundary Behavior ◽  
Stationary Regime ◽  
Product Form ◽  
Local Times ◽  
Nonnegative Orthant ◽  
State Dependent ◽  
The Times ◽  
And Diffusion

In this paper we consider reflected diffusions with positive and negative jumps, constrained to lie in the nonnegative orthant of ℝ n . We allow for the drift and diffusion coefficients, as well as for the directions of reflection, to be random fields over time and space. We provide a boundary behavior characterization, generalizing known results in the nonrandom coefficients and constant directions of the reflection case. In particular, the regulator processes are related to semimartingale local times at the boundaries, and they are shown not to charge the times the process expends at the intersection of boundary faces. Using the boundary results, we extend the conditions for product-form distributions in the stationary regime to the case when the drift and diffusion coefficients, as well as the directions of reflection, are random fields over space.

scholarly journals The rate of evaporation of droplets. Evaporation and diffusion coefficients, and vapour pressures of dibutyl phthalate and butyl stearate

1946 ◽  
Vol 186 (1006) ◽  
pp. 368-390 ◽  
Keyword(s):  
Diffusion Coefficients ◽  
Atmospheric Pressure ◽  
Dibutyl Phthalate ◽  
Droplet Evaporation ◽  
Medium Size ◽  
Good Accordance ◽  
Butyl Stearate ◽  
Rate Of Evaporation ◽  
Low Pressures ◽  
And Diffusion

The rate of evaporation of drops of dibutyl phthalate and butyl stearate of radius approx. 0.5 mm. has been studied by means of a microbalance over a range of atmospheric pressures down to approx. 0*1 mm. of mercury. Wide departures from Langmuir’s evaporation formula were found to occur at these low pressures, but results are in good accordance with the theory of droplet evaporation advanced by Fuchs which hitherto has not been tested experimentally. This experimental verification of Fuch’s theory for droplets of medium size evaporating at low pressures shows that the theory can be applied to the evaporation of very small drops at atmospheric pressure. The vapour pressures of the above liquids have been measured by Knudsen’s method and the evaporation and diffusion coefficients calculated fro n the experimental data.

Aluminophosphate Glasses with High Sulfate Content

1994 ◽  
Vol 353 ◽  
Author(s):  
Sergey V. Stefanovsky ◽  
Igor A. Ivanov ◽  
Anatolii N. Gulin
Keyword(s):  
Diffusion Coefficients ◽  
Glass Structure ◽  
Chemical Durability ◽  
Electric Resistivity ◽  
Melting Points ◽  
Sulfate Content ◽  
Leach Rate ◽  
High Sulfate ◽  
Aluminophosphate Glasses ◽  
And Diffusion

AbstractTo immobilize a high sulfate radioactive wastes a system Na2O-A12O3-P2O5-SO3 has been chosen as one where glasses have a relatively low melting points and good chemical durability. Glasses within partial system 44 Na2O, 20 A12O3 (36-x) P2O5 x SO3 have been prepared at 1000 °C. A possibility of assimilation up to 12 mole % of SO3 has been established. The basic properties of sulfate-containing glasses as density, microhardness, thermal expansion coefficient, transformation and deformation temperatures, viscosity, electric resistivity, leach rate of ions and diffusion coefficients of 22Na, 35S, 90Sr and 137Cs have been measured. Glass structure by infrared and EPR spectroscopies has been investigated.

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