Physical Rock Matrix Characterization: Structural and Mineralogical Heterogeneities in Granite

2008 ◽  
Vol 1124 ◽  
Author(s):  
Mikko Voutilainen ◽  
Suvi Lamminmäki ◽  
Jussi Timonen ◽  
Marja Siitari-kauppi ◽  
Daniel Breitner
Keyword(s):  
Pore Space ◽  
3D Structure ◽  
Rock Matrix ◽  
X Ray ◽  
Small Pore ◽  
Waste Repositories ◽  
Granite Samples ◽  
Space Characterization ◽  
Physical Rock

AbstractEvaluation of the transport and retardation properties of rock matrices that serve as host rock for nuclear waste repositories necessitates their thorough pore-space characterization. Relevant properties to be quantified include the diffusion depth and volume adjacent to water conducting features. The bulk values of these quantities are not sufficient due to the heterogeneity of mineral structure on the scale of the expected transport/interaction distances. In this work the 3D pore structure of altered granite samples with porosities of 5 to 15%, taken next to water conducting fractures at 180 200 m depth in Sievi, Finland, was studied. Characterization of diffusion pathways and porosity were based on quantitative autoradiography of rock sections impregnated with C14-labelled polymethylmethacrylate (PMMA). Construction of 3D structure from PMMA autoradiographs was tested. The PMMA method was augmented by field emission scanning electron microscopy and energy-dispersive X-ray analyses (FESEM/EDAX) in order to study small pore-aperture regions in more detail and to identify the corresponding minerals. The 3D distribution of minerals and their abundances were determined by X-ray microtomography. Combining the mineral specific porosity found by the PMMA method with these distributions provided us with a 3D porosity distribution in the rock matrix.

scholarly journals Pore-space characterization of an altered tonalite by X-ray computed microtomography and the14C-labeled-polymethylmethacrylate method

2012 ◽  
Vol 117 (B1) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Voutilainen ◽  
M. Siitari-Kauppi ◽  
P. Sardini ◽  
A. Lindberg ◽  
J. Timonen
Keyword(s):  
Pore Space ◽  
X Ray ◽  
Computed Microtomography ◽  
X Ray Computed ◽  
Space Characterization

Micro-X-ray Computed Tomography (μXRCT) Pore Space Characterization of Carbonate Samples

2017 ◽  
Author(s):  
Megan M. Smith ◽  
Susan A. Carroll ◽  
Amber Connor
Keyword(s):  
Computed Tomography ◽  
Pore Space ◽  
X Ray ◽  
X Ray Computed ◽  
Space Characterization

Characterisation of concrete, mortar and calcium silicate hydrated phases (CSH) and thorium retention analyses by ion beam techniques.

2012 ◽  
Vol 1475 ◽  
Author(s):  
Ursula Alonso ◽  
Tiziana Missana ◽  
Miguel Garcia-Gutierrez ◽  
Henar Rojo ◽  
Alessandro Patelli ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Cement Hydration ◽  
Ion Beam ◽  
X Ray ◽  
Tetravalent Actinide ◽  
Radioactive Waste Repositories ◽  
Edx Analyses ◽  
Waste Repositories ◽  
Beam Technique

ABSTRACTCement-based materials, like concrete and mortar, are widely used in radioactive waste repositories. A deep characterization of these heterogeneous materials, and of their main phases, is necessary to evaluate their capability of retaining critical radionuclides (RN).In this study, the ion beam technique micro- Particle Induced X- Ray Emission (μPIXE) is used to characterize the concrete and mortar used in the Spanish low level waste repository. Two calcium silicate hydrate (CSH) phases with different Ca/Si ratio are also studied, because they are known to be amongst the most relevant phases, formed upon cement hydration, that retain RN. The retention of thorium on the above mention materials, as relevant tetravalent actinide, is also analyzed. Results are compared with Scanning Electron Microscopy- Energy Dispersive X-Ray Spectroscopy (SEM-EDX) analyses.

Solving the 3D structure of metal nanoparticles

2007 ◽  
Vol 222 (11/2007) ◽  
Author(s):  
Anatoly Frenkel
Keyword(s):  
Metal Nanoparticles ◽  
Short Range ◽  
Short Range Order ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray ◽  
Particle Distributions ◽  
Structure Of Metal ◽  
X Ray Absorption

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.

scholarly journals Petrophysical characterization of coquinas from Morro do Chaves Formation (Sergipe-Alagoas Basin) by x-ray computed tomography

2018 ◽  
Vol 18 (3) ◽  
pp. 3-13
Author(s):  
Aline Maria Poças Belila ◽  
Michelle Chaves Kuroda ◽  
João Paulo Da Ponte Souza ◽  
Alexandre Campane Vidal ◽  
Osvair Vidal Trevisan
Keyword(s):  
Computed Tomography ◽  
Pore Space ◽  
Three Dimensional ◽  
Petroleum Reservoirs ◽  
Self Organizing Maps ◽  
X Ray ◽  
The Neural Network ◽  
Rock Structure ◽  
X Ray Computed

Carbonate rocks constitute a large number of petroleum reservoirs worldwide. Notwithstanding, the characterization of these rocks is still a challenge due to their high complexity and pore space variability, indicating the importance of further studies to reduce uncertainty in reservoir interpretation and characterization. This work was performed for coquina samples from Morro do Chaves Formation (Sergipe-Alagoas Basin), analogous to important Brazilian reservoirs. Computed tomography (CT) was used for three-dimensional characterization of rock structure. The neural network named Self-Organizing Maps (SOM) was used for CT images segmentation. According to our tests, CT demonstrated to be a consistent tool for quantitative and qualitative analysis of heterogeneous pore space, by the evaluation of porosity, connectivity and the representative elementary volume.

Synthesis and Characterization of a Three-dimensional Porous Compound: [Cu(H2O)6][{Cu(H2O)2}2{Cu(H2O)4H4W12O42}] · 12H2O

2008 ◽  
Vol 63 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Chun-jing Zhang ◽  
Ya-guang Chen ◽  
Dong-mei Shi ◽  
Hai-jun Pang
Keyword(s):  
Aqueous Solution ◽  
Magnetic Susceptibility ◽  
Elemental Analysis ◽  
3D Structure ◽  
Three Dimensional ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy

A novel transition metal polyoxotungstate, [Cu(H2O)6][{Cu(H2O)2}2{Cu(H2O)4H4W12O42}] · 12H2O (1), has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV/vis spectroscopy, and TG analysis. The paradodecatungstate anions [H2W12O42]10− are linked by CuO6 octahedra, forming a three-dimensional (3D) structure. The magnetic susceptibility of compound 1 in the temperature range 2 - 300 K shows the presence of antiferromagnetic interactions within the uniform Cu2・ ・ ・Cu3 chains

scholarly journals Contrast-Enhanced MicroCT for Virtual 3D Anatomical Pathology of Biological Tissues: A Literature Review

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sébastien de Bournonville ◽  
Sarah Vangrunderbeeck ◽  
Greet Kerckhofs
Keyword(s):  
Soft Tissues ◽  
Ex Vivo ◽  
Functional Characterization ◽  
3D Structure ◽  
Biological Tissues ◽  
X Ray ◽  
Musculoskeletal Tissues ◽  
Contrast Enhanced ◽  
Anatomical Pathology

To date, the combination of histological sectioning, staining, and microscopic assessment of the 2D sections is still the golden standard for structural and compositional analysis of biological tissues. X-ray microfocus computed tomography (microCT) is an emerging 3D imaging technique with high potential for 3D structural analysis of biological tissues with a complex and heterogeneous 3D structure, such as the trabecular bone. However, its use has been mostly limited to mineralized tissues because of the inherently low X-ray absorption of soft tissues. To achieve sufficient X-ray attenuation, chemical compounds containing high atomic number elements that bind to soft tissues have been recently adopted as contrast agents (CAs) for contrast-enhanced microCT (CE-CT); this novel technique is very promising for quantitative “virtual” 3D anatomical pathology of both mineralized and soft biological tissues. In this paper, we provided a review of the advances in CE-CT since the very first reports on the technology to date. Perfusion CAs for in vivo imaging have not been discussed, as the focus of this review was on CAs that bind to the tissue of interest and that are, thus, used for ex vivo imaging of biological tissues. As CE-CT has mostly been applied for the characterization of musculoskeletal tissues, we have put specific emphasis on these tissues. Advantages and limitations of multiple CAs for different musculoskeletal tissues have been highlighted, and their reproducibility has been discussed. Additionally, the advantages of the “full” 3D CE-CT information have been pinpointed, and its importance for more detailed structural, spatial, and functional characterization of the tissues of interest has been shown. Finally, the remaining challenges that are still hampering a broader adoption of CE-CT have been highlighted, and suggestions have been made to move the field of CE-CT imaging one step further towards a standard accepted tool for quantitative virtual 3D anatomical pathology.

scholarly journals Mineralogical and Chemical Characterization of Bajrawia Iron Ore, Sudan

2019 ◽  
Vol 8 (1) ◽  
pp. 8-14
Author(s):  
Ahmed Mohammedelmubarak Abbaker ◽  
Eltahir Mohamed Moslim ◽  
Montasir Sabbah El Din Elsalmawy
Keyword(s):  
Iron Ore ◽  
Chemical Characterization ◽  
High Porosity ◽  
Rock Matrix ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Iron Mineral ◽  
Fluorescence Energy

In this contribution, the mineralogical and chemical characterization of Bajrawia iron ore is investigated. The chemical analysis was conducted using atomic absorption spectroscopy, X-ray Fluorescence, Energy Dispersive X-ray and titration. The mineralogical characterization was obtained by optical microscopy and X-ray diffraction. The physical properties such as densities, water content and porosity were determined. It was found that Bajrawia iron ore contains about 35.5% Fe and some impurities like phosphorus and silica. Goethite is the major iron mineral associated with minor contents of hematite, kaolinite and quartz. SEM photo showed that the main minerals are goethite, clay minerals and quartz. The ore has low density because it has high porosity degree. This type of iron ore is disseminated in rock matrix and would be difficult to process.

scholarly journals Microstructural Characterization of Siltstone and Sandstone Pore Space by X-Ray Microtomography

2019 ◽  
Vol 42 (3) ◽  
pp. 281-288
Author(s):  
Jaquiel S. Fernandes ◽  
Carlos R. Appoloni ◽  
Celso P. Fernandes
Keyword(s):  
Pore Space ◽  
Microstructural Characterization ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document