Computation of hydraulic conductivity of porous materials using computer-assisted tomography

Soil Research ◽  
1996 ◽  
Vol 34 (5) ◽  
pp. 671 ◽  
Author(s):  
VK Phogat ◽  
LAG Aylmore
Keyword(s):  
Spatial Distribution ◽  
Hydraulic Conductivity ◽  
Glass Bead ◽  
Gamma Ray ◽  
Pore Space ◽  
Empirical Relationship ◽  
Soil Aggregate ◽  
Computer Assisted ◽  
Computer Assisted Tomography ◽  
Gamma Ray Attenuation

The spatial distribution of porosity and continuity of pore space in glass bead and soil aggregate systems has been characterised by application of computer-assisted tomography to gamma-ray attenuation measurements. It has been demonstrated that a useful empirical relationship between hydraulic conductivity and pore size and continuity for the glass bead system as measured by CAT scanning can be derived.

Evaluation of soil structure by using computer-assisted tomography

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 313 ◽  
Author(s):  
VK Phogat ◽  
LAG Aylmore
Keyword(s):  
Spatial Distribution ◽  
Bulk Density ◽  
Gamma Ray ◽  
Glass Tube ◽  
Total Porosity ◽  
Soil Samples ◽  
Computer Assisted ◽  
Wetting And Drying ◽  
Attenuation Coefficients ◽  
Computer Assisted Tomography

Computer assisted tomography applied to gamma ray attenuation (CAT scanning) has been evaluated as a method for directly measuring the spatial distribution of soil macroporosity and for monitoring changes which occur during wetting and drying processes, in a non-destructive manner. Total porosity calculated from the bulk density of soil and glass tube samples varying in bulk density from 0.759 to 1.602 g cm-3 correlated well with total porosity calculated from CAT scan data. The system was able to detect changes in bulk density for a loam soil of the order of 16 mg cm-3, and objects of 2.0 by 2.0 mm dimensions could be pictorially resolved in the scanning plane. Statistically, the system resolves pixels differing by at least 6.14% in attenuation coefficient value from surrounding pixels. Average macroporosity and the spatial and frequency distribution of macroporosity for soil samples were determined by assigning the value of zero macroporosity to pixels having gamma attenuation coefficients corresponding to the bulk density of a soil aggregate, 100% macroporosity to pixels with zero attenuation coefficients and proportional values to pixels with intermediate coefficients. The CAT scanning of soil samples before and after a wetting and drying cycle illustrated the greater reduction in macroporosity for soil wetted under flooding compared with that wetted under capillary action. The CAT scanning clearly has considerable potential for studying the spatial distribution of soil macrostructure and for monitoring the changes in macroporosity which occur during wetting and drying processes in soil columns.

scholarly journals Gamma-Ray Attenuation to Evaluate Soil Porosity: An Analysis of Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Luiz F. Pires ◽  
André B. Pereira
Keyword(s):  
Gamma Ray ◽  
Particle Density ◽  
Pore Space ◽  
Physical Property ◽  
Soil Bulk Density ◽  
Soil Porosity ◽  
Porous System ◽  
Soil Pore Space ◽  
Gamma Ray Attenuation ◽  
Dry Soil

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations ofϕare necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluateϕwere analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determineϕ. The results obtained point out a good correlation between both methods. However, whenϕis obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one.

Gamma-ray attenuation behaviors of hematite doped polymer composites

2020 ◽  
Vol 129 ◽  
pp. 103504 ◽  
Author(s):  
Mehmet Fatih Turhan ◽  
Ferdi Akman ◽  
Hasan Polat ◽  
Mustafa Recep Kaçal ◽  
İskender Demirkol
Keyword(s):  
Polymer Composites ◽  
Gamma Ray ◽  
Gamma Ray Attenuation ◽  
Doped Polymer
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