scholarly journals Use of Micro-Computed Tomography for Dental Studies in Modern and Fossil Odontocetes: Potential Applications and Limitations

2013 ◽  
Vol 8 ◽  
Author(s):  
Carolina Loch ◽  
Donald R Schwass ◽  
Jules A Kieser ◽  
R Ewan Fordyce
Keyword(s):  
Computed Tomography ◽  
Feeding Habits ◽  
Good Resolution ◽  
X Rays ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Pulp Cavity ◽  
Diagenetic Alteration ◽  
Extant Species ◽  
Non Destructive

Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins), providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs) recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such as metabolic or physiologic events. Micro-Computed Tomography (Micro-CT) is a non-invasive and non-destructive technique that allows 3-dimensional study of mineralized tissues, such as human teeth, and their physical properties. Teeth from extant dolphins (Cetacea: Odontoceti) and some fossil odontocetes were scanned in a Skyscan 1172 Micro-CT desktop system. X-rays were generated at 100 kV and 100 µA for extant samples, and at 80kV and 124 µA for fossils. 0.5 mm thick aluminum and copper filters were used in the beam. Reconstructed images were informative for most extant species, showing a good resolution of the enamel layer, dentine and pulp cavity. Greyscale changes in the dentinal layers were not resolved enough to show GLGs. Visualization of the internal structure in fossil cetacean teeth depended on the degree of diagenetic alteration in the specimen; undifferentiated enamel and dentine regions probably reflect secondary mineralization. However, internal details were finely resolved for one fossil specimen, showing the enamel, internal layers of dentine and the pulp cavity. Micro-CT has been proven to be a useful tool for resolving the internal morphology of fossil and extant teeth of cetaceans before they are sectioned for other morphological analyses; however some methodological refinements are still necessary to allow better resolution of dentine for potential application in non-destructive age determination studies. 

scholarly journals Micro-computed tomography for natural history specimens: a handbook of best practice protocols

2019 ◽  
Author(s):  
Kleoniki Keklikoglou ◽  
Sarah Faulwetter ◽  
Eva Chatzinikolaou ◽  
Patricia Wils ◽  
Jonathan Brecko ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Natural History ◽  
Best Practice ◽  
Ct Imaging ◽  
Three Dimensions ◽  
X Rays ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Ct Technology ◽  
Non Destructive

Micro-computed tomography (micro-CT or microtomography) is a non-destructive imaging technique using X-rays which allows the digitisation of an object in three dimensions. The ability of micro-CT imaging to visualise both internal and external features of an object, without destroying the specimen, makes the technique ideal for the digitisation of valuable natural history collections. This handbook serves as a comprehensive guide to laboratory micro-CT imaging of different types of natural history specimens, including zoological, botanical, palaeontological and geological samples. The basic principles of the micro-CT technology are presented, as well as protocols, tips and tricks and use cases for each type of natural history specimen. Finally, data management protocols and a comprehensive list of institutions with micro-CT facilities, micro-CT manufacturers and relative software are included.

Defect Detection of Metal Injection Modeling by Micro Computed Tomography

2012 ◽  
Vol 229-231 ◽  
pp. 1445-1448
Author(s):  
Wei Yun Huang ◽  
Chang Da Chen ◽  
Yen Nien Chen ◽  
Wei Jen Shih ◽  
Chih Han Chang
Keyword(s):  
Computed Tomography ◽  
Injection Molding ◽  
Hot Isostatic Pressing ◽  
Cost Effective ◽  
High Volume ◽  
Metal Injection Molding ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Destructive Testing ◽  
Non Destructive

Metal injection molding (MIM) is a combination of metal powder and injection molding technology. The main advantage of this technology for material parts with small and complex shape is to manufacture cost-effective and high-volume products. The main processing steps include mixing, injection molding, debinding , sintering, and hot isostatic pressing (HIP) in order to reduce internal porosity of metals, then to improve mechanical properties. This study is based on non-destructive testing method to determine the possible defect inside the internal structure of the MIM parts. Three types of parts with and without HIP were evaluated investigated in this study. The micro computed tomography (Micro-CT) is used to scan these parts. Based the reconstructed section images from CT, the defects can be identified. It showed that with HIP the much of detects could be reduced. To conclude, Micro CT could be used to detect, in a non-destructive way, the internal detect within MIM parts can be found out in the micro-CT images, so that the manufacturing process could be modified to improve the quality of MIM parts.

scholarly journals Applying micro-computed tomography for porosity analysis of polypropylene modified with microspheres

2021 ◽  
Vol 332 ◽  
pp. 01017
Author(s):  
Piotr Szewczykowski
Keyword(s):  
Computed Tomography ◽  
Solid Material ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Material Density ◽  
X Ray ◽  
Blowing Agent ◽  
Central Measuring ◽  
Porosity Analysis ◽  
Non Destructive

Porosity of polypropylene samples was investigated by applying X-ray micro-computed tomography (micro-CT), which is getting more and more popular as a non-destructive method. Microspheres were applied as a blowing agent at three concentrations: 3%, 6% and 9% by weight. Tensile testing specimens were obtained by injection molding technology and its central, measuring part were examined by micro – CT. Results were compared to porosity calculated based on difference in porous and solid material density. Pore size distribution curves were discussed as well.

scholarly journals Characterization of Coloured Gemstones by X-ray Micro Computed Tomography

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 178
Author(s):  
René Heyn ◽  
Abraham Rozendaal ◽  
Anton Du Plessis ◽  
Carene Mouton
Keyword(s):  
Computed Tomography ◽  
Low Cost ◽  
Micro Ct ◽  
Fracture Detection ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Complementary Method ◽  
Color Changes ◽  
Non Destructive

The monetary value of gemstones is based on five variables: rarity, cut, weight, color and clarity. The latter refers to internal impurities and defects. Fashion may also dictate demand and price. To enhance some of these features and value, gemstones are treated. Disclosure or nondisclosure thereof has been controversial and affected consumer confidence. Most of these treatments are difficult to detect with the naked eye and accurately quantify with traditional optical and analytical methods. X-ray micro computed tomography (micro-CT or μCT) is proposed as a relatively low cost, physically non-destructive and complementary method to detect and quantify clarity enhancement and also to provide a unique 3D fingerprint of each gemstone. A collection of 14 cut colored gemstones was selected. Micro-CT scans allowed fracture detection, their distribution and calculation of filler volume as well as 3D mapping of inclusions, surface and internal imperfections and artificially induced modifications. As a result the method allows the construction of a digital twin. X-ray exposure could however induce unwanted color changes. This effect was minimized or eliminated by optimizing dosage and exposure time.

scholarly journals Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Volume Ratio ◽  
Bone Volume ◽  
Osteochondral Defects ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Trabecular Thickness ◽  
Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

scholarly journals Non-destructive characterization of additively manufactured components with x-ray computed tomography for part qualification: A study with laboratory and synchrotron x-rays

2021 ◽  
Vol 173 ◽  
pp. 110894
Author(s):  
Ercan Cakmak ◽  
Philip Bingham ◽  
Ross W. Cunningham ◽  
Anthony D. Rollett ◽  
Xianghui Xiao ◽  
...  
Keyword(s):  
Computed Tomography ◽  
X Rays ◽  
X Ray ◽  
X Ray Computed ◽  
Non Destructive ◽  
Non Destructive Characterization

scholarly journals Using micro-computed tomography to reveal the anatomy of adult Diaphorina citri Kuwayama (Insecta: Hemiptera, Liviidae) and how it pierces and feeds within a citrus leaf

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Alba-Tercedor ◽  
Wayne B. Hunter ◽  
Ignacio Alba-Alejandre
Keyword(s):  
Computed Tomography ◽  
Significant Advance ◽  
Micro Ct ◽  
Diaphorina Citri ◽  
Ct Reconstruction ◽  
Internal Anatomy ◽  
Micro Computed Tomography ◽  
Citrus Leaf ◽  
Teaching Aids ◽  
Adult Feeding

AbstractThe Asian citrus psyllid (ACP), Diaphorina citri, is a harmful pest of citrus trees that transmits Candidatus Liberibacter spp. which causes Huanglongbing (HLB) (citrus greening disease); this is considered to be the most serious bacterial disease of citrus plants. Here we detail an anatomical study of the external and internal anatomy (excluding the reproductive system) using micro-computed tomography (micro-CT). This is the first complete 3D micro-CT reconstruction of the anatomy of a psylloid insect and includes a 3D reconstruction of an adult feeding on a citrus leaf that can be used on mobile devices. Detailed rendered images and videos support first descriptions of coxal and scapus antennal glands and sexual differences in the internal anatomy (hindgut rectum, mesothoracic ganglion and brain). This represents a significant advance in our knowledge of ACP anatomy, and of psyllids in general. Together the images, videos and 3D model constitute a unique anatomical atlas and are useful tools for future research and as teaching aids.

MicroCT protocols for scanning of embryos and juvenile Hexaplex trunculus v1

2021 ◽  
Author(s):  
Eva Chatzinikolaou ◽  
Kleoniki Keklikoglou
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
3D Imaging ◽  
Imaging Technique ◽  
Ct Scanning ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Gastropod Species ◽  
Biological Studies ◽  
Hexaplex Trunculus

Micro-computed tomography (micro-CT) is a high-resolution 3D-imaging technique which is now increasingly applied in biological studies focusing on taxonomy and functional morphology. The creation of virtual representations of specimens can increase availability of otherwise underexploited and inaccessible samples. This protocol aims to standardise micro-CT scanning procedures for embryos and juveniles of the marine gastropod species Hexaplex trunculus.

scholarly journals Micro-Computed Tomography (Micro-CT) Evaluation of Effects of Different Rotary Glide Path Techniques on Canal Transportation and Centering in Curved Root Canals

2019 ◽  
Vol 25 ◽  
pp. 6351-6358
Author(s):  
Gabrielė Česaitienė ◽  
Tadas Venskutonis ◽  
Vita Mačiulskienė ◽  
Vaidotas Cicėnas ◽  
Vykintas Samaitis ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Root Canals ◽  
Glide Path ◽  
Ct Evaluation ◽  
Canal Transportation ◽  
Curved Root Canals

Quantitative micro-computed tomography analysis and rheological investigation of Nitrile rubber/Rockwool composites

2021 ◽  
pp. 002199832110338
Author(s):  
Elisson BD da Rocha ◽  
Ana Maria F de Sousa ◽  
Ana Lúcia N da Silva ◽  
Cristina RG Furtado ◽  
Marcos V Colaço ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Elastic Modulus ◽  
Aspect Ratio ◽  
Volume Fraction ◽  
Nitrile Rubber ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Rubber Composites ◽  
Ratio Data ◽  
Ct Analysis

This study reports the reinforcement degree investigation of two types of rockwool fibers (F1 and F2), in nitrile rubber composites. The micro-computed tomography (micro-CT) 3D images showed that both fibers were well-dispersed in the NBR matrix, without a preferential orientation. The micro-CT analysis also allowed quantifying volume fraction, inter-fiber distance, and aspect ratio. Those morphometric parameters were used for supporting the composites rheological behavior assessment. Changes in the elastic modulus and phase angle followed the same trend of the inter-fiber distance values, regardless the type of fiber. Both volume fraction and aspect ratio data from the micro-CT analysis were used to predict theoretical values of elastic modulus using the Guth-Gold and modified Guth-Gold equations, and the results obtained were compared to the rheological experimental data. This analysis was helpful to better understand the rockwool fibers reinforcement degree differences in the production of the nitrile rubber composites.

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