Damage to soil physical properties caused by soil sampler devices as assessed by gamma ray computed tomography

Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 857 ◽  
Author(s):  
Luiz F. Pires ◽  
Osny O. S. Bacchi ◽  
Klaus Reichardt
Keyword(s):  
Computed Tomography ◽  
Physical Properties ◽  
Bulk Density ◽  
Soil Sample ◽  
First Generation ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
241Am Source ◽  
Sampling Procedures ◽  
Gamma Ray Computed Tomography

Soil sample physical properties can be greatly affected during soil sampling procedures. Improper procedures can impose modifications on soil sample structure and consequently lead to wrong measurements of soil properties. The objective of this work was to evaluate the damage caused by soil samplers to soil structure through the analysis of computed tomography (CT) images. A first generation tomograph was used, having a 241Am source and a 7.62 × 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube. Results confirm the effect of soil sampler devices on the structure of soil samples, and that the compaction caused during sampling causes significant alterations to soil bulk density. Through the use of CT it was possible to determine the level of compaction and to make a detailed analysis of the soil bulk density distribution within the soil sample.

Soil bulk density evaluation by conventional and nuclear methods

Soil Research ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 97 ◽  
Author(s):  
L. C. Timm ◽  
L. F. Pires ◽  
K. Reichardt ◽  
R. Roveratti ◽  
J. C. M. Oliveira ◽  
...  
Keyword(s):  
Bulk Density ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Soil Science ◽  
Tukey Test ◽  
Nuclear Methods ◽  
Density Values ◽  
Density Evaluation ◽  
Gamma Ray Computed Tomography

Among the methods used to measure soil bulk density, the following have been prominent: paraffin sealed clod (PS), volumetric ring (VR), and the modern methods like gamma ray computed tomography (GCT) and the neutron/gamma surface gauge (SG). The objective of this work was to compare soil bulk density values obtained through these methods, with the aim of assisting researchers on the choice of the more appropriate method. For this, a 200-m spatial transect was chosen in an experimental area cultivated with coffee, belonging to ESALQ/USP, Piracicaba, SP, Brazil. The SG readings were first taken in the field and thereafter soil samples were collected at 8 different points, spaced at 25 m, for the other methods. The lowest values of soil bulk density were obtained for the SG method (average 1.468 g/cm3) and the highest for the PS (average 1.685 g/cm3), which was similar to the GCT method (average 1.684 g/cm3). The average soil bulk density for the VR method, which has been used in soil science as a standard method, was 1.544 g/cm3. The Tukey test indicates that the PS and GCT methods do not differ significantly (P > 0.05). They do differ in comparison with VR and SG, which also do not differ among themselves.

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

scholarly journals GAMMA-RAY COMPUTED TOMOGRAPHY (CT) TECHNIQUE FOR TREE STEM INVESTIGATION

2018 ◽  
Vol 12 (2) ◽  
pp. 73
Author(s):  
Bayu Azmi
Keyword(s):  
Computed Tomography ◽  
Gamma Ray ◽  
Parallel Beam ◽  
Ct Technique ◽  
Gamma Ray Computed Tomography ◽  
Tree Stem

TEKNIK COMPUTED TOMOGRAPHY (CT) SINAR GAMMA UNTUKINVESTIGASIBATANG POHON. Pepohonan memiliki peran yang penting dalam kehidupan manusia. Pohon-pohon dapat meningkatkan kualitas udara, menstabilkan temperatur, dan lain sebagainya. Akhir-akhir ini terdapat beberapa insiden pohon tumbang dan mengakibatkan korban jiwa. Investigasi batang pohon telah dilakukan dengan menggunakan teknik computed tomography (CT) sinar gamma untuk mempelajari kondisi bagian dalam dari batang pohon tersebut. Batang tersebut dipindai menggunakan tomografi generasi pertama yang disebut metode pemindaian parallel beam. 137Cs dengan aktivitas 80 mCi memancarkan foton gamma yang menembus batang pohon dan diterima oleh detektor sintilasi Nal(Tl) pada sisi lainnya. Kedua sumber radiasi gamma dan detektor dikolimasi menggunakan timah hitam dengan diameter celahnya sebesar 5 mm. Terdapat 128 data proyeksi yang kemudian direkonstruksi menjadi citra. Dibutuhkan waktu sekitar 522 menit untuk mendapatkan 128 data proyeksi tersebut. Citra hasil rekonstruksi menunjukkan bahwa terdapat variasi densitas dan dua lubang pada batang pohon tersebut dengan jelas. CT sinar gamma menjadi salah satu teknik yang menjanjikan untuk investigasi pohon. Pengembangan lebih lanjut dibutuhkan untuk mengurangi waktu pemindaian dan meningkatkan kualitas citra.

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