scholarly journals Reconstruction and Analysis of Tight Sandstone Digital Rock Combined with X-Ray CT Scanning and Multiple-Point Geostatistics Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yun Lei
Keyword(s):  
Pore Space ◽  
Full Range ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Multiple Point ◽  
Tight Sandstone ◽  
Sandstone Sample ◽  
X Ray ◽  
Digital Rock ◽  
Experimental Values

Unconventional rocks such as tight sandstone and shale usually develop multiscale complex pore structures, with dimensions ranging from nanometers to millimeters, and the full range can be difficult to characterize for natural samples. In this paper, we developed a new hybrid digital rock construction approach to mimic the pore space of tight sandstone by combining X-ray CT scanning and multiple-point geostatistics algorithm (MPGA). First, a three-dimensional macropore digital rock describing the macroscopic pore structure of tight sandstone was constructed by micro-CT scanning. Then, high-resolution scanning electron microscopy (SEM) was performed on the tight sandstone sample, and the three-dimensional micropore digital rock was reconstructed by MPGA. Finally, the macropore digital rock and the micropore digital rock were superimposed into the full-pore digital rock. In addition, the nuclear magnetic resonance (NMR) response of digital rocks is simulated using a random walk method, and seepage simulation was performed by the lattice Boltzmann method (LBM). The results show that the full-pore digital rock has the same anisotropy and good connectivity as the actual rock. The porosity, NMR response, and permeability are in good agreement with the experimental values.

scholarly journals Modeling of 3D Rock Porous Media by Combining X-Ray CT and Markov Chain Monte Carlo

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Wei Lin ◽  
Xizhe Li ◽  
Zhengming Yang ◽  
Shengchun Xiong ◽  
Yutian Luo ◽  
...  
Keyword(s):  
Porous Media ◽  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Heterogeneous Porous Media ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Sandstone Sample ◽  
Digital Rock ◽  
Multi Scale

Abstract Rocks contain multi-scale pore structures, with dimensions ranging from nano- to sample-scale, the inherent tradeoff between imaging resolution and sample size limits the simultaneous characterization of macro-pores and micro-pores using single-resolution imaging. Here, we developed a new hybrid digital rock modeling approach to cope with this open challenge. We first used micron-CT to construct the 3D macro-pore digital rock of tight sandstone, then performed high-resolution SEM on the three orthogonal surfaces of sandstone sample, thus reconstructed the 3D micro-pore digital rock by Markov chain Monte Carlo (MCMC) method; finally, we superimposed the macro-pore and micro-pore digital rocks to achieve the integrated digital rock. Maximal ball algorithm was used to extract pore-network parameters of digital rocks, and numerical simulations were completed with Lattice-Boltzmann method (LBM). The results indicate that the integrated digital rock has anisotropy and good connectivity comparable with the real rock, and porosity, pore-throat parameters and intrinsic permeability from simulations agree well with the values acquired from experiments. In addition, the proposed approach improves the accuracy and scale of digital rock modeling and can deal with heterogeneous porous media with multi-scale pore-throat system.

scholarly journals Validating marker-less pose estimation with 3D x-ray radiography

2021 ◽  
Author(s):  
Dalton D Moore ◽  
Jeffrey D Walker ◽  
Jason N MacLean ◽  
Nicholas G Hatsopoulos
Keyword(s):  
Pose Estimation ◽  
High Speed ◽  
Full Range ◽  
Three Dimensional ◽  
Small Degree ◽  
X Ray ◽  
Neural Recordings ◽  
Radiography System ◽  
Median Error ◽  
Natural Movement

To reveal the neurophysiological underpinnings of natural movement, neural recordings must be paired with accurate tracking of limbs and postures. Here we validate the accuracy of DeepLabCut (DLC) by comparing it to a 3D x-ray video radiography system that tracks markers placed under the skin (XROMM). We record behavioral data simultaneously with XROMM and high-speed video for DLC as marmosets engage in naturalistic foraging and reconstruct three-dimensional kinematics in a shared coordinate system. We find that DLC tracks position and velocity of 12 markers on the forelimb and torso with low median error (0.272 cm and 1.76 cm/s, respectively) corresponding to 2.9% of the full range of marker positions and 5.9% of the range of speeds. For studies that can accept this relatively small degree of error, DLC and similar marker-less pose estimation tools enable the study of more naturalistic, unconstrained behaviors in many fields including non-human primate motor control.

scholarly journals High-throughput three-dimensional visualization of root system architecture of rice using X-ray computed tomography

2020 ◽  
Author(s):  
Shota Teramoto ◽  
Satoko Takayasu ◽  
Yuka Kitomi ◽  
Yumiko Arai-Sanoh ◽  
Takanari Tanabata ◽  
...  
Keyword(s):  
High Throughput ◽  
System Architecture ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Root System Architecture ◽  
Visualization Method ◽  
Process Flow ◽  
X Ray ◽  
X Ray Computed ◽  
Crown Roots

Abstract Background: X-ray computed tomography (CT) allows us to visualize root system architecture (RSA) beneath the soil, non-destructively and in a three-dimensional (3-D) form. However, CT scanning, reconstruction processes, and root isolation from X-ray CT volumes, take considerable time. For genetic analyses, such as quantitative trait locus mapping, which require a large population size, a high-throughput RSA visualization method is required. Results: We have developed a high-throughput process flow for the 3-D visualization of rice (Oryza sativa) RSA (consisting of radicle and crown roots), using X-ray CT. The process flow includes use of a uniform particle size, calcined clay to reduce the possibility of visualizing non-root segments, use of a higher tube voltage and current in the X-ray CT scanning to increase root-to-soil contrast, and use of a 3-D median filter and edge detection algorithm to isolate root segments. Using high-performance computing technology, this analysis flow requires only 10 min (33 s, if a rough image is acceptable) for CT scanning and reconstruction, and 2 min for image processing, to visualize rice RSA. This reduced time allowed us to conduct the genetic analysis associated with 3-D RSA phenotyping. In 2-week-old seedlings, 85% and 100% of radicle and crown roots were detected, when 16 cm and 20 cm diameter pots were used, respectively. The X-ray dose per scan was estimated at < 0.09 Gy, which did not impede rice growth. Using the developed process flow, we were able to follow daily RSA development, i.e., 4-D RSA development, of an upland rice variety, over three weeks. Conclusions: We developed a high-throughput process flow for 3-D rice RSA visualization by X-ray CT. The X-ray dose assay on plant growth has shown that this methodology could be applicable for 4-D RSA phenotyping. We named the RSA visualization method ‘RSAvis3D’ and are confident that it represents a potentially efficient application for 3-D RSA phenotyping of various plant species.

scholarly journals A new seahorse (Teleostei: Syngnathidae: Hippocampus) from south-western Australia

Zootaxa ◽  
2010 ◽  
Vol 2613 (1) ◽  
pp. 61 ◽  
Author(s):  
RALPH FOSTER ◽  
MARTIN F. GOMON
Keyword(s):  
New Species ◽  
Soft Tissue ◽  
Continental Shelf ◽  
Western Australia ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Dorsal Midline ◽  
X Ray ◽  
Dorsal Fin ◽  
A New Species

A new species of syngnathid fish, Hippocampus paradoxus sp. nov., from mid-continental shelf waters of south-western Australia is described from the only known specimen. It can be distinguished from all congeners, including the very similar H. minotaur Gomon 1997, by the following features: the lack of a dorsal fin, a series of fleshy, fin-like lobes along the dorsal midline of the trunk and tail and an extremely robust cleithrum and prominent first nuchal plate. In addition to the traditional methods of syngnathid taxonomists, X-ray microtomography (CT scanning) was employed and demonstrated to be a valuable research tool for examining seahorse species that are problematic due to reduced ossification and small size. CT scanning is more capable of imaging poorly ossified and soft tissue regions than traditional radiography and provides a detailed three dimensional view of salient features.

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.

Three-Dimensional Analysis of Carbon Nanotube Networks in Interconnects by Electron Tomography without Missing Wedge Artifacts

2010 ◽  
Vol 16 (2) ◽  
pp. 210-217 ◽  
Author(s):  
Xiaoxing Ke ◽  
Sara Bals ◽  
Daire Cott ◽  
Thomas Hantschel ◽  
Hugo Bender ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Full Range ◽  
Three Dimensional ◽  
X Ray ◽  
Quantitative Studies ◽  
Transmission Electron ◽  
Carbon Nanotube Networks ◽  
Semiconductor Contact

AbstractThe three-dimensional (3D) distribution of carbon nanotubes (CNTs) grown inside semiconductor contact holes is studied by electron tomography. The use of a specialized tomography holder results in an angular tilt range of ±90°, which means that the so-called “missing wedge” is absent. The transmission electron microscopy (TEM) sample for this purpose consists of a micropillar that is prepared by a dedicated procedure using the focused ion beam (FIB) but keeping the CNTs intact. The 3D results are combined with energy dispersive X-ray spectroscopy (EDS) to study the relation between the CNTs and the catalyst particles used during their growth. The reconstruction, based on the full range of tilt angles, is compared with a reconstruction where a missing wedge is present. This clearly illustates that the missing wedge will lead to an unreliable interpretation and will limit quantitative studies.

scholarly journals Three dimensional soil organic matter distribution, accessibility and microbial respiration in macro-aggregates using osmium staining and synchrotron X-ray CT

2016 ◽  
Author(s):  
Barry G Rawlins ◽  
Joanna Wragg ◽  
Christina Rheinhard ◽  
Robert C Atwood ◽  
Alasdair Houston ◽  
...  
Keyword(s):  
Organic Matter ◽  
Transition Probabilities ◽  
Solid Phase ◽  
Pore Space ◽  
Three Dimensional ◽  
Soil Core ◽  
Length Scales ◽  
X Ray ◽  
Mineral Phases ◽  
Indicator Variograms

Abstract. The spatial distribution and accessibility of organic matter (OM) to soil microbes in aggregates – determined by the fine-scale, 3-D distribution of organic matter, pores and mineral phases – may be an important control on the magnitude of soil heterotrophic respiration (SHR). Attempts to model SHR at fine scales requires data on the transition probabilities between adjacent pore space and soil OM, a measure of microbial accessibility to the latter. We used a combination of osmium staining and synchrotron X-ray CT to determine the 3-D (voxel) distribution of these three phases (scale 6.6 μm) throughout nine aggregates taken from a single soil core (range of organic carbon (OC) concentrations 4.2–7.7 %). Prior to the synchrotron analyses we had measured the magnitude of SHR for each aggregate over 24 hours under controlled conditions (moisture content and temperature). We test the hypothesis that larger magnitudes of SHR will be observed in aggregates with shorter length scales of OM variation (i.e. more frequent, and possibly more finely disseminated, OM and a larger number of aerobic microsites). After scaling to their OC concentrations, there was a six-fold variation in the magnitude of SHR for the nine aggregates. The distribution of pore volumes, pore shape and volume normalised surface area were similar for each of the nine aggregates. The overall transition probabilities between OM and pore voxels were between 0.02 and 0.03, significantly smaller than those used in previous simulation studies. We computed the length scales over which OM, pore and mineral phases vary within each aggregate using indicator variograms. The median range of models fitted to variograms of OM varied between 178 and 487 μm. The linear correlation between these median length scales of OM variation and the magnitudes of SHR for each aggregate was −0.42, providing some evidence to support our hypothesis. We require a larger number of observations to make a statistical inference. There was no evidence to suggest a statistical relationship between OM:pore transition probabilities and the magnitudes of aggregate SHR. The solid-phase volume proportions (45–63 %) of OM we report for our aggregates were surprisingly large by comparison to those assumed in previous modelling approaches. We suggest this requires further assessment using accurate measurements of OM bulk density in a range of soil types.

scholarly journals Morphology and anatomy of the angiosperm fruit Baccatocarpon, incertae sedis, from the Maastrichtian Deccan Intertrappean Beds of India

2019 ◽  
Vol 59 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Steven R. Manchester ◽  
Dashrath K. Kapgate ◽  
Deepak D. Ramteke ◽  
Sharadkumar P. Patil ◽  
Selena Y. Smith
Keyword(s):  
Three Dimensional ◽  
Central India ◽  
Ct Scanning ◽  
Single Species ◽  
X Ray ◽  
Incertae Sedis ◽  
Reflected Light ◽  
Thin Walled

Abstract Distinctive permineralized fruits of Baccatocarpon mohgaoense (Paradkar & Dixit) comb. nov. have been collected from several sites in the late Maastrichtian of the Deccan Intertrappean beds of Central India. We describe the peculiar fruits in detail, based on combined investigations by reflected light and X-ray CT scanning. Three-dimensional renderings and virtual slices confirm that the fruits have two lateral single-seeded locules and a central sterile chamber filled with parenchyma. The endocarp is thin-walled and opens apically longitudinal valves. Here we validate the generic name Baccatocarpon Bhowal & Sheikh ex Manchester, Ramteke, Kapgate & S.Y. Smith and recognize a single species, for which the name Baccatocarpon mohgaoense (Paradkar & Dixit) comb. nov. has priority. We document the occurrence of this species in cherts from the paleobotanical sites known as Bhutera, Keria, Mahurzari, Mohgoankalan, Paladaun, Marai Patan and Shibla. The systematic affinity of these fruits remains mysterious.

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