scholarly journals Computed Tomography to Estimate the Representative Elementary Area for Soil Porosity Measurements

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jaqueline Aparecida Ribaski Borges ◽  
Luiz Fernando Pires ◽  
André Belmont Pereira
Keyword(s):  
Computed Tomography ◽  
Gamma Ray ◽  
Strong Relationship ◽  
Soil Porosity ◽  
Soil Physics ◽  
Tomographic Images ◽  
Section Area ◽  
Ideal Tool ◽  
Porosity Measurements ◽  
Elementary Area

Computed tomography (CT) is a technique that provides images of different solid and porous materials. CT could be an ideal tool to study representative sizes of soil samples because of the noninvasive characteristic of this technique. The scrutiny of such representative elementary sizes (RESs) has been the target of attention of many researchers related to soil physics field owing to the strong relationship between physical properties and size of the soil sample. In the current work, data from gamma-ray CT were used to assess RES in measurements of soil porosity (ϕ). For statistical analysis, a study on the full width at a half maximum (FWHM) of the adjustment of distribution ofϕat different areas (1.2 to 1162.8 mm2) selected inside of tomographic images was proposed herein. The results obtained point out that samples with a section area corresponding to at least 882.1 mm2were the ones that provided representative values ofϕfor the studied Brazilian tropical soil.

scholarly journals Soil porosity distribution representative elementary area analyzed through gamma-ray computed tomography

2016 ◽  
Vol 30 (4) ◽  
pp. 447-456 ◽  
Author(s):  
Talita Rosas Ferreira ◽  
Luiz Fernando Pires
Keyword(s):  
Computed Tomography ◽  
Gamma Ray ◽  
Soil Porosity ◽  
Porosity Distribution ◽  
Tomography System ◽  
Computed Tomography Images ◽  
Γ Ray ◽  
Computed Tomography Image ◽  
Gamma Ray Computed Tomography ◽  
Elementary Area

Abstract This study aims to use γ-ray computed tomography images to define the representative elementary area of the soil porosity distribution. Different textured soils from Southeast Brazil and different schemes of areas were analyzed. The image acquisition was performed in 2006 using a first generation γ-ray computed tomography system equipped with 241Am radioactive source. Consecutive increasing areas located at the center (scheme 1), the inferior (scheme 2) and superior (scheme 3) borders of the sample computed tomography image, with size areas ranging from 1.2 to 678.8 mm², were selected. The full width at a half maximum parameter was used to describe the samples soil porosity distribution and mathematical analysis concepts were adopted to define the representative elementary area. The representative elementary areas found for the sandy soil (Geric Ferralsol) and clayey soils (Rhodic Ferralsol and Eutric Nitosol) were respectively: 514.3, 514.3 and 555.4 mm² (scheme 1); 279.5, 393.3 and 457.4 mm² (scheme 2); and 457.4, 457.4 and 457.4 mm² (scheme 3). The results confirmed that the representative elementary area were influenced by the soil texture and management. Different schemes were noticed to provide different representative elementary areas for the same soil, which suggests that this procedure was efficient to detect the heterogeneity inside the soil samples.

DEVELOPMENT AND IMPLEMENTATION OF A PORTABLE NUCLEONIC COMPUTED TOMOGRAPHY SYSTEM WITH CLAMP-ON-FEATURES FOR ENGINEERING INSPECTION

2015 ◽  
Vol 77 (17) ◽  
Author(s):  
Jaafar Abdullah ◽  
Hearie Hassan ◽  
Mohamad Rabaie Shari ◽  
Maslina Mohd Ibrahim ◽  
Nolida Yussup ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gamma Ray ◽  
Bubble Column ◽  
Great Promise ◽  
Hydrodynamic Behavior ◽  
Tomographic Images ◽  
Tomography System ◽  
Set Up ◽  
System Configurations

The development and implementation of a portable nucleonic computed tomography system with clamp-on-features, called “GammaSpider”, employing gamma-ray for engineering inspection is briefly discussed. Depending on the object to be inspected, a small isotopic gamma-ray source, in combination of a NaI(Tl) scintillation detector and an autonomous mechanical gantry set-up are used. The basic theoretical aspects, the system configurations and the other features are presented. This system is capable of generating high quality tomographic images and thus, offers great promise for in-situ engineering inspection. It is successfully used to inspect blockages in pipelines, to examine wooden electric poles and to study hydrodynamic behavior of multiphase flow in a bubble column.  Some of the preliminary results are presented in this paper.

Representative Gamma-ray Computed Tomography Calibration for Applications in Soil Physics

2011 ◽  
Vol 41 (1) ◽  
pp. 21-28 ◽  
Author(s):  
L. F. Pires ◽  
R. C. J. Arthur ◽  
O. O. S. Bacchi ◽  
K. Reichardt
Keyword(s):  
Computed Tomography ◽  
Gamma Ray ◽  
Soil Physics ◽  
Gamma Ray Computed Tomography

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 computed tomography for scanning of agarwood tree: Data analysis and comparison

2020 ◽  
Author(s):  
Mohd Fitri Abdul Rahman ◽  
Lahasen Dahing ◽  
Muhamad Noor Izwan Ishak ◽  
Hearie Hassan ◽  
Nur Liyana Abdullah ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Data Analysis ◽  
Gamma Ray ◽  
Tree Data ◽  
Gamma Ray Computed Tomography

Gamma-Ray Computed Tomography for Imaging of Multiphase Flows

2013 ◽  
Vol 85 (7) ◽  
pp. 1002-1011 ◽  
Author(s):  
André Bieberle ◽  
Hans-Ulrich Härting ◽  
Swapna Rabha ◽  
Markus Schubert ◽  
Uwe Hampel
Keyword(s):  
Computed Tomography ◽  
Multiphase Flows ◽  
Gamma Ray ◽  
Gamma Ray Computed Tomography
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