Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 99 for “"X-ray computed tomography"”.
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Hip fracture risk predictions by x-ray computed tomography
Thesis (Ph. D.)--Massachusetts Institute of Technology, Harvard-MIT Division of Health Sciences and Technology Program in Medical Engineering and Medical Physics, 1988.
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Image Reconstruction for X-ray Computed Tomography in Security Screening Applications
<p>X-ray tomographic systems have increasingly widespread use in security screening applications. For example, most major airports now utilize X-ray CT</p> <p>systems for efficient screening of baggage and cargo. While decades of research has benefited CT for medical diagnostics, a number of …
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Dimensional measurements with X-ray Computed Tomography and application to Cultural Heritage
L'abstract è presente nell'allegato / the abstract is in the attachment
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Three dimensional reconstruction of plant roots via low energy x-ray computed tomography
… Existing efforts have successfully employed X-ray computed tomography to visualize plant roots in three-dimensions and to quantify their complexity in a non-invasive and non-destructive manner. However, they used expensive and less accessible industrial or medical tomographic systems. This …
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Characterization of the cellular structure of foamed cement using x-ray computed tomography
… at varying densities as well as to demonstrate X-ray computed tomography (CT) as a valuable three dimensional (3D) characterization technique for the investigation of cementitious materials. Three replicate samples were taken from four foamed cement mixes with target densities of 300, 400, 500, …
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A Manufacturing Process for Single Micron Resolution Optical Gratings Used in X-ray Computed Tomography
X-ray Computed Tomography (CT) is a process that produces three-dimensional x-ray images, allowing for better diagnosis and analysis of complex internal medical conditions. New advances in the optical techniques used in this process promise to produce better results while reducing patient risk. One …
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Theoretical and Experimental Evaluation of Spatial Resolution in a Variable Resolution X-Ray Computed Tomography Scanner
<p>A variable resolution x-ray (VRX) computed tomography (CT) scanner can image objects of various sizes with greatly improved spatial resolution. The scanner employs an angulated discrete detector and achieves the resolution boost by matching the detector angulation to the scanner field of view …
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X-ray Computed Tomography as a method of cryoprotectant concentration measurement and ice detection: application to organ cryopreservation.
… dispusimos de un NanoCT cuyas bajas energías de rayos X consiguen medir la atenuación de rayos X en función la concentración de dimetilsulfóxido debido principalmente al átomo de azufre que constituye la molécula. Los resultados muestran una atenuación de los rayos X proporcional a la …
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Investigation of fiber and cracking behavior for conventional and ultra-high performance concretes using x-ray computed tomography
… the collection of micro-scale data using x-ray computed tomography (CT). The quasi-static phenomena investigated included the tensile, compression, and reinforcing bar pull-out behavior of both ultra-high performance concrete (UHPC) and conventional concrete. Ballistic damage of UHPC samples …
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Synthesis and characterization of cationic contrast agents & imaging of articular cartilage using X-ray computed tomography and magnetic resonance
… tantalum oxide nanoparticles (Ta2O5 NPs) for x-ray Computed Tomography (CT) imaging; and Gadopentetate-dilysine (Gd(DTPA)Lys2), a gadolinium small molecule for Magnetic Resonance (MR) imaging. These cationic contrast agents are attracted to the strong negative fixed charge of extracellular GAG …
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An investigation into the complementary capabilities of X-ray computed tomography and hyperspectral imaging of drill core in geometallurgy
… such as 2D hyperspectral imaging (HSI) and 3D Xray computed tomography (XCT) have the potential to be incorporated into the machine learning dataset. Hyperspectral imaging is a critical component of continuous drill core scanning in geometallurgy for identifying problematic minerals in …
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A design for a high energy X-ray computed tomography sensor for the study of solidification fronts in aluminum
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1997.
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Three dimensional quantitative textural analysis of nickel sulphide ore using X-ray computed tomography and grey level co-occurrence matrices on drill core
… challenge. In this study, the use of 3D X-ray computed tomography (XCT) is proposed as an innovative solution to non-destructively image the internal structure of drill core. Thereafter, an established, discipline independent two dimensional (2D) image analysis technique known as grey level …
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Assessment of hydro-physical properties of some crusting soils in four different soil form as revealed by micro-focus x-ray computed tomography in Limpopo Province, South Africa
… in four different soil form by using X-ray Computed Tomography, Characterizing micro-morphometric of crusting soil’s pore system, quantifying soil structure degradation through crusting development and visualizing hydro physical properties in all four-soil form. Micro X-ray Computed …
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Automated defect detection and evaluation in X-ray CT images
X-ray computed tomography gains increasing popularity for industrial quality inspection tasks. It is a challenge however to use it in a fully automated assembly line, which requires robust algorithms for volumetric image analysis on noisy data. This work provides methods for the automatic detection …
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Development of nondestructive evaluation methodologies for polymer composite components prepared via additive manufacturing.
… internal damage with ultrasonic testing and X-Ray computed tomography and investigating the subsequent decrease in mechanical performance. The objective of the second study is to determine the effectiveness of rotational eddy current testing in evaluating common manufacturing features of …
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Geometry-driven filamentary structures : elastic gridshells, weaves, clasps, and knots
… techniques (e.g., 3D laser scanning, and X-ray computed tomography). First, we study the shape and the mechanical response of elastic gridshells, the three-dimensional structure of which results from the out-of-plane buckling of an initially flat and biaxial network of rods. A purely …
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Visualizing fluidized beds with X-rays
… minimum fluidization velocity experiments, X-ray computed tomography (CT), X-ray stereography, and particle tracking to fluidized beds of glass beads, ground walnut shell, and ground corncob operating with a variety of flow conditions. 3-D local, time-averaged gas holdup is calculated from CT …
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Examination of the small scale slow cookoff behavior of a cast modified double base propellant
… Morphological behavior was examined using X-ray computed tomography to provide qualitative information on void formation due to gradual heating.
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