Fracturing Mechanism of Compressed Hollow-Cylinder Sandstone Evaluated by X-ray Micro CT Scanning

2022 ◽  
pp. 319-343
Author(s):  
Sheng-Qi Yang
Keyword(s):  
Hollow Cylinder ◽  
Ct Scanning ◽  
Micro Ct ◽  
X Ray ◽  
Fracturing Mechanism

scholarly journals A Preliminary Report on the Use of Bench-Top X-Ray Micro-Computerised Tomography to Study the Malpighian Tubules of the Overwintering Seven Spotted LadybirdCoccinella septempunctataL. (Coleoptera: Coccinellidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Duncan Bell ◽  
Lewis Woolnough ◽  
David Mortimore ◽  
Nick Corps ◽  
Diana M. Hudson ◽  
...  
Keyword(s):  
Coccinella Septempunctata ◽  
Ct Scanning ◽  
Small Sample ◽  
Malpighian Tubules ◽  
Micro Ct ◽  
Computerised Tomography ◽  
X Ray ◽  
High Concentrations ◽  
Very High ◽  
Metallic Pollutants

The application of micro-CT scanning techniques on a small sample of “Seven-spot ladybirds”Coccinella septempunctata,collected in December 2009, identified an accumulation of material with a very high, relative X-ray attenuation value in the malpighian tubules of most but not all of the individuals sampled. The passage of metals such as cadmium in soil through a food chain to finally accumulate in high concentrations in ladybirds and lacewings has been previously reported. The identification of the dense material found in our sample of ladybirds, its origin, and the process by which it accumulates in, and is processed by, the malpighian tubules is the challenge ahead. The authors speculate that a straightforward means of monitoring levels of metallic pollutants in the environment might emerge.

scholarly journals Finding fossils in Malapa breccia – medical CT scanning or micro-CT scanning?

2017 ◽  
Vol 113 (11/12) ◽  
Author(s):  
Jacqueline S. Smilg
Keyword(s):  
Computed Tomography ◽  
Lower Energy ◽  
Ct Scanning ◽  
Cost Effective ◽  
High Energy ◽  
X Rays ◽  
Micro Ct ◽  
X Ray ◽  
Mechanical Preparation ◽  
X Ray Computed

Computed tomography (CT) imaging of fossils has revolutionised the field of palaeontology, allowing researchers to gain a better understanding of fossil anatomy, preservation and conservation. Micro focus X-ray computed tomography (μXCT) has been far more extensively used for these purposes than medical CT (XCT) – mostly because of the exquisite detail that the μXCT scanning modality, using slices of micron thicknesses, can produce. High energy X-rays can potentially penetrate breccia more effectively than lower energy beams. This study demonstrates that lower energy beams produce superior images for prioritising breccia for preparation. Additionally, XCT scanners are numerous, accessible, fast and relatively cost-effective when compared to μXCT scanners – the latter are not freely available, scanning times are much longer and there are significant limitations on the size and weight of scannable objects. Breccia blocks from Malapa were scanned at high and lower energy and images were analysed for image quality, artifact and certainty of diagnosis. Results show that lower energy images are deemed superior to higher energy images for this particular application. This finding, taken together with the limitations associated with the use of μXCT for the imaging of the large breccia from Malapa, shows that XCT is the better modality for this specific application. The ability to choose fossil-bearing breccia, ahead of manual mechanical preparation by laboratory technicians, would allow for the optimal use of limited resources, manual preparatory skills as well as the curtailment of costs.

scholarly journals X-ray micro-CT scanning reveals temporal separation of male harm and female kicking during traumatic mating in seed beetles

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170550 ◽  
Author(s):  
Liam R. Dougherty ◽  
Leigh W. Simmons
Keyword(s):  
Callosobruchus Maculatus ◽  
Ct Scanning ◽  
Three Dimensions ◽  
Micro Ct ◽  
Temporal Separation ◽  
X Ray ◽  
Seed Beetle ◽  
Proximate Mechanisms ◽  
Fitness Consequences ◽  
Seed Beetles

In the seed beetle Callosobruchus maculatus , the male intromittent organ is covered in sharp spines that pierce the female copulatory tract wall during mating. Although the fitness consequences of traumatic mating are well studied in this species, we know much less about how the male and female genitalia interact during mating. This is partly due to the fact that genital interactions occur primarily inside the female, and so are difficult to observe. In this study, we use X-ray micro-CT scanning to examine the proximate mechanisms of traumatic mating in C. maculatus in unprecedented detail. We show that this technique can be used to identify female tissue damage before the melanization of wound sites. We visualize the positioning of the male intromittent organ inside the female copulatory tract during mating, and show how this relates to tract wounding in three dimensions. By scanning pairs flash-frozen at different times during mating, we show that significant tract wounding occurs before the onset of female kicking. There is thus some degree of temporal separation between the onset of wounding and the onset of kicking, which supports recent suggestions that kicking is not an effective female counter-adaptation to reduce copulatory wounding in this species. We also present evidence that the sharp teeth protruding from the female tract wall are able to pierce the spermatophore as it is deposited, and may thus function to aid sperm release.

scholarly journals Morpho-densitometric traits for quinoa (Chenopodium quinoa Willd.) seed phenotyping by two X-ray micro-CT scanning approaches

2019 ◽  
Vol 90 ◽  
pp. 102829 ◽  
Author(s):  
Laura Gargiulo ◽  
Åsa Grimberg ◽  
Ritva Repo-Carrasco-Valencia ◽  
Anders S. Carlsson ◽  
Giacomo Mele
Keyword(s):  
Chenopodium Quinoa ◽  
Ct Scanning ◽  
Micro Ct ◽  
X Ray

scholarly journals Tracking the Magmatic Flow in a Dyke-Sill Hybrid System using a Multi-Method Approach (AMS, SPO, X-ray micro-CT) for Petrofabrics Characterization (Lessines, Belgium)

2020 ◽  
Author(s):  
Antoine Triantafyllou ◽  
Jean-Marc Baele ◽  
Hervé Diot ◽  
Veerle Cnudde ◽  
Redouane Meftah ◽  
...  
Keyword(s):  
Hybrid System ◽  
Ct Scanning ◽  
Hydrothermal Activity ◽  
Micro Ct ◽  
Upper Ordovician ◽  
Heterogeneous Distribution ◽  
X Ray ◽  
The North ◽  
Magmatic Body ◽  
Multi Method Approach

<p>Understanding how magmas are transported and collected within the crust is crucial for constraining the dynamic of shallow plumbing volcanic systems and associated hydrothermal activity. This study focuses on the Lessines dioritic intrusion exposed in the SW margin of the Brabant Massif in Belgium. The kilometric subvolcanic body was emplaced around 419 Ma and is thought to result from the emplacement of multiple sills which intruded a lithostratigraphic discontinuity within Upper Ordovician sedimentary units. Our study aims to constrain how magmatic flow is recorded through different fabrics, how this flow varies across the solidified magmatic intrusion and how primary fabrics can be affected by subsequent hydrothermal overprint.</p><p>The petrofabric of 40 oriented diorite samples was investigated with a multi-methods approach: (i) Anisotropy of Magnetic Susceptibility (AMS) along with K-temperature curves determined using low field KLY-4S Kappabridge susceptibilimeter (at LIENS lab, University of La Rochelle, France), (ii) Shape Preferred Orientations (SPO) of melanocratic phenocrysts (pseudomorphosed amphibole and biotite) as well as leucocratic phenocrysts (quartz and sericitized felspars s.l.) determined by the Intercepts method applied on optical scans of three adjacent cut faces of each sample, (iii) X-ray micro-CT scanning of five selected samples using the HECTOR device at UGCT lab (Ghent University, Belgium).</p><p>AMS and melanocratic fabrics SPO are mainly marked by prolate shaped ellipsoids. Both subsets show similar and homogeneous orientation of their structures through the studied area, with E-W striking foliations dipping 70° to the North to subvertical. Leucocratic petrofabric SPO shows more heterogeneous distribution with a similar E-W to N120-striking foliations but generally subhorizontal to low dipping structures (< 30°). This discrepancy is thought to be due to differential record of the subvolcanic phenocrysts during the ultimate emplacement and solidification of the Lessines magmatic body. These results combined to field observations (e.g., enclave orientations, columnar joints, borehole logs) suggest that the Lessines intrusion is a complex dyke-sill hybrid system, made of a main subvertical dyke-like structure that fed lateral sills bodies.</p>

scholarly journals The Oxford Dodo. Seeing more than ever before: X-ray micro-CT scanning, specimen acquisition and provenance

2020 ◽  
pp. 1-9
Author(s):  
J. M. Warnett ◽  
Mark A. Williams ◽  
Paul F. Wilson ◽  
M. Paul Smith
Keyword(s):  
Ct Scanning ◽  
Micro Ct ◽  
X Ray

scholarly journals How different is similar – exploring development of Ceropegia sandersonii pitfall flowers to elucidate convergent evolution of floral synorganization

2020 ◽  
Author(s):  
Annemarie Heiduk ◽  
Dewi Pramanik ◽  
Marlies Spaans ◽  
Loes Gast ◽  
Nemi Dorst ◽  
...  
Keyword(s):  
Convergent Evolution ◽  
Genetic Background ◽  
Ct Scanning ◽  
Floral Organ ◽  
Floral Traits ◽  
Micro Ct ◽  
Mads Box ◽  
Mads Box Genes ◽  
X Ray ◽  
Mads Box Gene

Abstract Background: Lantern plants from the genus Ceropegia (Apocynaceae-Asclepiadoideae) have radially symmetric pitfall flowers that are an outstanding example of functional floral complexity with high synorganization of specialized organs. The evolutionary origin and development of these complex flowers is unclear, and the genetic background of floral organ formation is unknown. Flowers with similar deceptive pollination strategies and floral traits convergently evolved in non-related plant lineages. The partially bilaterally flattened trap flowers of pipevines are functionally similar to Ceropegia pitfall flowers; many orchid taxa evolved complex fully bilaterally flattened flowers with specialized organs to trap pollinators. This study is the first to investigate the genetic background of pitfall flower development in Ceropegia, and to explore (i) convergent evolution of extremely synorganized and complex flowers as well as (ii) the homology of a highly specialized floral organ, the gynostegial corona. Methods: We obtained transcriptomes from C. sandersonii early floral buds and mature sepals, petals, and gynostegia, and analyzed differential expression of selected MADS-box genes in buds and mature floral organs using RT-PCR. In addition, we studied floral ontogeny and vascularization using SEM and 3D X-ray micro-CT scanning. Results: We identified ten phases of floral development from primordia to mature flowers, and for the first time visualized the vascular system of mature Ceropegia pitfall flowers in a 3D-model. We identified 14 MADS-box gene homologs, representing all major MADS-box gene classes, in the floral transcriptomes of Ceropegia. Vascular bundle patterns, as revealed by 3D X-ray micro-CT scanning, in combination with high expression of GLOBOSA and AGAMOUS indicate a staminoid origin of this highly specialized floral organ which starts developing from stage seven onwards. Interestingly, AGAMOUS-LIKE6 was neither expressed in early floral buds nor in any mature floral organ, in line with the radial symmetry of all Ceropegia floral organs. Conclusion: We detected differential expression of MADS-box genes involved in Ceropegia floral organ identity and propose a new ABCDE-model for parachute flowers. We compare this with current models of unrelated plants with similar floral traits but (partially) bilaterally flattened flowers, i.e. Aristolochia fimbriata and Erycina pusilla. With this comparative approach we lay the foundation for understanding the genetic mechanisms driving convergent evolution of highly specialized deceptive trap flowers.

scholarly journals Cyclodextrin and TiF4 Nanocomplex on Enamel Demineralization

2020 ◽  
Vol 31 (4) ◽  
pp. 423-430
Author(s):  
Thiago Vieira ◽  
Adílis K. Alexandria ◽  
Lilian H. Amaral ◽  
Aline de A. Neves ◽  
Ricardo T. Lopes ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Lower Percentage ◽  
Micro Ct ◽  
Surface Microhardness ◽  
Cross Sectional ◽  
Titanium Tetrafluoride ◽  
X Ray ◽  
Bovine Enamel ◽  
Mineral Loss

Abstract The aim of this study was to assess the effect of a newly developed nanocomplex formed of hydroxypropyl-b-cyclodextrin and 1% titanium tetrafluoride (TiF4) after distinct complexation periods (12/72 h) on demineralization of bovine enamel in vitro. Enamel blocks (n=60) were allocated in different groups: Mili-Q water, hydroxypropyl-b-cyclodextrin, 1% TiF4, hydroxypropyl-b-cyclodextrin + 1% TiF4 after 12 h of complexation and hydroxypropyl-b-cyclodextrin + 1% TiF4 after 72 h of complexation. The samples were evaluated by surface microhardness, cross-sectional microhardness and micro-CT. Scanning electron microscopy and energy dispersive X-ray spectrometry (SEM/EDX) were also obtained. Hydroxypropyl-b-cyclodextrin + 1% TiF4 after 12 h complexation resulted in lower percentage of surface microhardness loss compared to Mili-Q water, hydroxypropyl-b-cyclodextrin, 1% TiF4 and hydroxypropyl-b-cyclodextrin + 1% TiF4 after 72 h of complexation group, with a large effect size (from 1.307 to 2.943) and high power (84.9 to 99%). All groups resulted in similar integrated mineral loss (ΔZ) obtained by both internal microhardness and micro-CT techniques. Enamel treated with TiF4 and TiF4 + hydroxypropyl-b-cyclodextrin groups showed a TiO2 glaze-layer, while EDX evaluation identified Ti. The solution containing the inclusion complex of hydroxypropyl-b-cyclodextrin + TiF4 with 12 h of complexation period demonstrated a significant ability to reduce surface demineralization of sound enamel under an artificial cariogenic challenge.

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

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