Gas permeability measurement through a porous materials

2002 ◽  
Vol 2002 (10) ◽  
pp. 12
Keyword(s):  
Porous Materials ◽  
Gas Permeability ◽  
Permeability Measurement

Evaluation of Pettys Nonlinear Model in Wood Permeability Measurement

Holzforschung ◽  
2001 ◽  
Vol 55 (1) ◽  
pp. 82-86
Author(s):  
J. Lu ◽  
F. Bao ◽  
Y. Zhao
Keyword(s):  
Nonlinear Model ◽  
Gas Permeability ◽  
Optimization Algorithms ◽  
Optimization Techniques ◽  
Curvilinear Relationship ◽  
Grid Search ◽  
Permeability Measurement ◽  
Iterative Optimization ◽  
Starting Values ◽  
Least Squares Fit

Summary To calculate the effective radii of two conductive elements in series in wood specimens by using the gas permeability measurement, the four parameters from the curvilinear relationship of superficial specific permeability against reciprocal mean pressure as illustrated in Petty's model must be evaluated. This paper describes a detailed procedure for obtaining such parameters by using the least-squares fit calculated from a statistical analysis system (SAS) program. Three different iterative optimization algorithms and starting points were used separately to fit the Petty's nonlinear model based on the same experimental data from one specimen of birch. The estimate of the parameters: A = 35.38 darcy, B = 80.51 darcy, l = 0.19 darcy atm, m = 6.34 darcy atm was recommended for the fitted model. Compared to the results on the estimate of parameters obtained in the previous papers, this estimate for the parameters was a global minimum, thus it was a refinement and more accurate. Since the Gauss-Newton method resulted in almost the same convergence results for all the three sets of starting values with the least iterations in the evaluation, it was the preferred optimization algorithm both for simplicity and accuracy in solving the Petty's model. Because the same solutions for all three iterative optimization algorithms were obtained by using two different sets of starting points produced from the grid search, a grid search seemed to be very helpful for finding reasonable starting values for various iterative optimization techniques.

Optimization of 3-D Gas Permeability Measurement: Utilization of Field Data

2009 ◽  
Author(s):  
Hadi Belhaj ◽  
Bechir Mtawaa ◽  
Mohammed Haroun ◽  
Terry Lay
Keyword(s):  
Field Data ◽  
Gas Permeability ◽  
Permeability Measurement

scholarly journals Gas Permeability of Cellulose Aerogels with a Designed Dual Pore Space System

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2688 ◽  
Author(s):  
Kathirvel Ganesan ◽  
Adam Barowski ◽  
Lorenz Ratke
Keyword(s):  
Porous Materials ◽  
Cell Walls ◽  
Gas Permeability ◽  
Pore Space ◽  
Nitrogen Adsorption ◽  
Space System ◽  
Fixed Amount ◽  
Hydrophilic Lipophilic Balance ◽  
Wide Range ◽  
The Impact

The gas permeability of a porous material is a key property determining the impact of the material in an application such as filter/separation techniques. In the present study, aerogels of cellulose scaffolds were designed with a dual pore space system consisting of macropores with cell walls composing of mesopores and a nanofibrillar network. The gas permeability properties of these dual porous materials were compared with classical cellulose aerogels. Emulsifying the oil droplets in the hot salt–hydrate melt with a fixed amount of cellulose was performed in the presence of surfactants. The surfactants varied in physical, chemical and structural properties and a range of hydrophilic–lipophilic balance (HLB) values, 13.5 to 18. A wide range of hierarchical dual pore space systems were produced and analysed using nitrogen adsorption–desorption analysis and scanning electron microscopy. The microstructures of the dual pore system of aerogels were quantitatively characterized using image analysis methods. The gas permeability was measured and discussed with respect to the well-known model of Carman–Kozeny for open porous materials. The gas permeability values implied that the kind of the macropore channel’s size, shape, their connectivity through the neck parts and the mesoporous structures on the cell walls are significantly controlling the flow resistance of air. Adaption of this new design route for cellulose-based aerogels can be suitable for advanced filters/membranes production and also biological or catalytic supporting materials since the emulsion template method allows the tailoring of the gas permeability while the nanopores of the cell walls can act simultaneously as absorbers.

Gas permeability measurement in polyethylene and its copolymer films

2007 ◽  
Vol 28 (9) ◽  
pp. 2528-2532 ◽  
Author(s):  
M. Gholizadeh ◽  
J. Razavi ◽  
S.A. Mousavi
Keyword(s):  
Gas Permeability ◽  
Permeability Measurement ◽  
Copolymer Films

The flexible Ca-test: An improved performance in a gas permeability measurement system

2011 ◽  
Vol 82 (5) ◽  
pp. 054702 ◽  
Author(s):  
Eun Ho Song ◽  
Young Wook Park ◽  
Jin Hwan Choi ◽  
Tae Hyun Park ◽  
Jin Wook Jeong ◽  
...  
Keyword(s):  
Measurement System ◽  
Gas Permeability ◽  
Permeability Measurement ◽  
Improved Performance

Determination of Physical Properties of Isotropic Porous Materials by Impedance Tube

2009 ◽  
Author(s):  
Sanjay Sharma ◽  
Dennis Siginer
Keyword(s):  
Porous Medium ◽  
Fluid Flow ◽  
Physical Properties ◽  
Porous Materials ◽  
Low Frequency ◽  
Permeability Measurement ◽  
Impedance Tube ◽  
Acoustical Properties ◽  
Acoustical Method

Simulation of fluid flow in porous materials depends upon the accuracy of permeability measurement. This study details the development of an acoustical method to determine permeability of porous medium. Standardized acoustical testing for low frequency using impedance tube is carried out to determine the acoustical properties of the fibers. Physical properties of porous medium are determined by reverse calculation from the acoustical properties. The acoustical method is validated by comparing the measured acoustical properties of the porous medium by the analytical method. A variety of foams and fibers are tested using this methodology.

An optimised preconditioning procedure for gas permeability measurement

2002 ◽  
Vol 35 (1) ◽  
pp. 22-27 ◽  
Author(s):  
M. Carcassès ◽  
A. Abbas ◽  
J. -P. Ollivier ◽  
J. Verdier
Keyword(s):  
Gas Permeability ◽  
Permeability Measurement
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