On some physical properties of six aspen clones

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Stavros Avramidis ◽  
Shawn D. Mansfield
Keyword(s):  
Physical Properties ◽  
Diffusion Coefficients ◽  
Water Sorption ◽  
Sorption Site ◽  
Site Distribution ◽  
Heat Of Wetting ◽  
Specific Permeability ◽  
Desorption Isotherms ◽  
And Diffusion ◽  
Sorption Characteristics

Abstract Basic physical properties including density, permeability, water sorption characteristics and diffusion coefficients in desorption were measured with specimens taken from for six aspen clone trees harvested in northeastern British Columbia. Results showed that there are significant differences among the clones in their specific permeability and somewhat in the heat of wetting, but very little was found among density, diffusion coefficients and desorption isotherms. These results indicate that the porous structure could be variable among clones whereas the sorption site distribution and availability might not.

Thermodiffusion in a Binary Fluid Mixture Subject to External Vibrations: Effect of Variable Physical Properties

2011 ◽  
Author(s):  
A. Parsa ◽  
M. Z. Saghir
Keyword(s):  
Physical Properties ◽  
Diffusion Coefficients ◽  
Thermal Gradient ◽  
Microgravity Environment ◽  
Fluid Mixture ◽  
Binary Fluid ◽  
Numerical Studies ◽  
External Forces ◽  
And Diffusion ◽  
Different Levels

A microgravity environment is essential for studying the phenomenon of thermodiffusion in order to suppress the microscopic flows in the mixture. It is, however, noted that the residual micro accelerations (g-jitters) in the space laboratories is produced by several sources such as crew activities, mechanical systems, thrusters firing, spacecraft docking, etc. Such external forces lead to significant flows which can induce convection that may affect the accuracy of the experiment. Consequently, an appropriate interpretation of the space experimental results relies on theoretical and numerical studies of the g-jitter effect on the temperature and the concentration fields. In this paper, we have modeled the thermodiffusion experiment subjected to different levels of vibration when the steady gravity is assumed zero. A rectangular cavity that is subjected to a thermal gradient is filled with a binary mixture (water and isopropanol) and put under the influence of different levels of vibrations. The thermal gradient is applied perpendicular to the vibration. All physical properties including density, mass diffusion and thermodiffusion coefficients are assumed variable as function of temperature and concentration using PC-SAFT equation of state. It is found that using variable physical properties including density and diffusion coefficients make the results more realistic in comparison with the constant model especially in cases with higher Rayleigh vibrations.

Water Sorption Characteristics of Sugar Impregnated Strawberries

1995 ◽  
Vol 13 (8-9) ◽  
pp. 1993-2010 ◽  
Author(s):  
S.L. Viadles ◽  
L.F. Malec ◽  
L.N. Gerschenson ◽  
S.M. Alzamora
Keyword(s):  
Water Sorption ◽  
Sorption Characteristics

Water sorption and diffusion in a short-side-chain perfluorosulfonic acid ionomer membrane for PEMFCS: effect of temperature and pre-treatment

Desalination ◽  
2006 ◽  
Vol 193 (1-3) ◽  
pp. 398-404 ◽  
Author(s):  
M.G. De Angelis ◽  
S. Lodge ◽  
M. Giacinti Baschetti ◽  
G.C. Sarti ◽  
F. Doghieri ◽  
...  
Keyword(s):  
Water Sorption ◽  
Effect Of Temperature ◽  
Side Chain ◽  
Perfluorosulfonic Acid ◽  
Short Side ◽  
Pre Treatment ◽  
And Diffusion

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.

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