Compton scattering tomography for agricultural measurements

Cruvinel, P. E.; Balogun, F.A.

doi:10.1590/s0100-69162006000100017

Cited by 17 publications

(8 citation statements)

References 9 publications

(6 reference statements)

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“…in which n e (electrons per cm 3 ) is the electron density and σ IC (cm 2 ) is the total cross-section for the process of incoherent scattering derived from the Klein-Nishina equation (Cruvinel and Balogun, 2006). Vinegar and Wellington (1987) presented a generalized equation (Equation 7), which demonstrates the dependence of the linear attenuation coefficient with the density and the atomic number of the absorber.…”

Section: Process Of Radiation Interactionmentioning

confidence: 99%

Use of nuclear techniques in soil science: A literature review of the Brazilian contribution

Pires¹,

Cássaro²,

Correchel³

2021

Revista Brasileira De Ciência Do Solo

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This review presents the basic research and some applications of the gamma-ray attenuation, neutron gauges, and 137 Cs fallout techniques for studying soil physical processes and properties. The selected studies aimed to give the readers a general idea of the use of these nuclear techniques carried out by Brazilian researchers in the past decades. It is expected to assist future researchers by identifying knowledge gaps and opportunities for applying the methods presented here. Around 100 studies were selected for this review. The papers dealing with gamma-ray attenuation are mostly related to the analysis of soil radiation interactions, the measurement of basic soil physical properties, the evaluation of hydraulic conductivity, water retention curve, and soil mechanical analysis. Neutron gauge applications are related to monitoring the water distribution and balance at the field scale, procedures for calibrating the existing gauge for the Brazilian soils, and analyzing the spatial and temporal variability of the soil water content. The 137 Cs methodology involves studies about the erosion and sediment deposition in small watersheds and riparian zones, the spatial variability of 137 Cs inventories at reference sites, and the measurement of sediment spatial distributions. Future studies with the gamma-ray attenuation methodology should focus on a better comprehension of the photon interaction with the soil and a correct selection of photon energies to investigate contrasting soils. This is mandatory for adopting it as a reliable tool for soil characterization. This review also revealed that the challenges for the future use of the 137 Cs fallout technique involve the continuous decrease of the 137 Cs activity worldwide, including in Brazil. Advances in detection systems (gamma spectrometers) will be required to overcome this issue. Future studies should focus on the use of correction factors related to the enrichment of fine particles during the transport of sediments to improve the estimates obtained through the conversion models. The use of neutron gauges to detect soil water content at the field scale depends on the adoption of reliable calibration curves. Then, comprehending how soil properties alter this curve and how it affects the water balance is a study of great interest. Motivated by strict regulations on the use of radioactive materials, the adoption of gauges with less activity is becoming a new goal. Thus, the development of more effective systems of neutron detection is crucial.

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Section: Process Of Radiation Interactionmentioning

confidence: 99%

Use of nuclear techniques in soil science: A literature review of the Brazilian contribution

Pires¹,

Cássaro²,

Correchel³

2021

Revista Brasileira De Ciência Do Solo

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“…This is why the concept of Compton imaging was initiated and developed in last few decades. We shall not recall the early steps of Compton imaging and refer the reader to [4], but give some references on recent interests in Compton imaging for historical object research and conservation 15 [5], land mine detection [6], agricultural measurements [7], battery functioning [8], nondestructive testing [9] and soil studies [10]. One of the main advantages of Compton scattering imaging over X-ray transmission imaging is its high sensitivity to the local electron density, even for materials with high X-ray absorption coefficients.…”

Section: Aq3mentioning

confidence: 99%

New “improved” Compton scatter tomography modality for investigative imaging of one-sided large objects

Cebeiro

Nguyen

Morvidone

et al. 2017

Inverse Problems in Science and Engineering

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In an effort to promote Compton scatter tomography (CST) as an adequate modality for imaging the inner parts of large objects limited in a half-space of R 3 AQ1, we show that the standard CST can be 'improved' in some particular sense by 'doubling' the scanning mechanism. To this end, one needs to record for each position of a detector the scattered flux densities at two energies of scattered radiation, instead of one. Curiously, thanks to geometric inversion, this 'double' scanning may be converted into a transmission scanning on an apparent object, not along a straight line path as usual, but along a folded line in the shape of a V -line path. It has been proved that this V -line transmission scanning admits a well-defined reconstruction procedure. Therefore, the proposed CST with 'double' scanning, which solves the above imaging inverse problem, shows an 'improved' reconstructed image as compared to the standard one. We present theoretical arguments to support this claim as well as numerical simulations to illustrate its working and its viability AQ2 . ARTICLE HISTORY

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“…After obtaining the images, it is possible to store data in a two-dimensional matrix (2D) (CRUVINEL & BALOGUN, 2006).…”

Section: Introductionmentioning

confidence: 99%

Application of x-ray computed tomography in the evaluation of soil porosity in soil management systems

2014

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ABSTRACT:The study aimed to evaluate a methodology to quantify the porosity of the soil using computed tomography in areas under no-tillage, conventional tillage and native forest. Three soil management systems were selected for the study: forest, conventional tillage and no-tillage. In each soil management system, undisturbed soil samples were collected in the surface layer (0.0 to 0.10 m). The tomographic images were obtained using a X-ray microtomography. After obtaining the images, they were processed, and a methodology was evaluated for image conversion into numerical values. The statistical method which provided the greatest accuracy was the percentile method. The methodology used to analyze the tomographic image allowed quantifying the porosity of the soil under different soil management. The method enabled the characterization of soil porosity in a non-evasive and non-destructive way.KEYWORDS: precision farming, image processing, X-ray microtomography, macroporosity. APLICAÇÃO DA TOMOGRAFIA COMPUTADORIZADA DE RAIOS X NA AVALIAÇÃO DA POROSIDADE DO SOLO EM SISTEMAS DE MANEJO DO SOLORESUMO: O estudo teve por objetivo avaliar uma metodologia para quantificar a porosidade do solo, utilizando a tomografia computadorizada, em áreas sob sistema de semeadura direta, preparo convencional e mata nativa. Três sistemas de manejo do solo foram selecionados para o estudo: mata, preparo convencional e semeadura direta. Em cada sistema de manejo do solo, foram coletadas amostras indeformadas de solo na camada superficial (0.0-0.10 m). As imagens tomográficas foram obtidas utilizando um sistema de microtomografia de raios-X. Após a obtenção das imagens, estas foram processadas, e uma metodologia foi avaliada para conversão da imagem em valores numéricos. O método estatístico que proporcionou maior exatidão foi o método do percentil. A metodologia utilizada para analisar a imagem tomográfica permitiu quantificar a porosidade do solo em diferentes condições de manejo de solo. O método viabilizou a caracterização da porosidade do solo de forma não evasiva e não destrutiva.

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Compton scattering tomography for agricultural measurements

Cited by 17 publications

References 9 publications

Use of nuclear techniques in soil science: A literature review of the Brazilian contribution

Use of nuclear techniques in soil science: A literature review of the Brazilian contribution

New “improved” Compton scatter tomography modality for investigative imaging of one-sided large objects

Application of x-ray computed tomography in the evaluation of soil porosity in soil management systems

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