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Showing 1 to 20 of 93 for “"Tortuosity"”.
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Computational model of coronary tortuosity
Coronary tortuosity is the abnormal curving and twisting of the coronary arteries. Although the phenomenon of coronary tortuosity is frequently encountered by cardiologists its clinical significance is unclear. It is known that coronary tortuosity has significant influence on the hemodynamics …
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Macromolecular drug release from porous implants : sources of matrix tortuosity
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1984.
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Lattice Boltzmann simulation of non-Darcy flow in synthetic 2D and 3D porous media models and numerical characterization of tortuosity
Includes bibliographical references (leaves 93-98).
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Leveraging Modelling and Machine Learning for the Analysis of Curvilinear Structures in Medical Images
… links between a number of diseases and the tortuosity of curvilinear anatomical structures such as corneal nerve fibres, suggesting that tortuosity changes might detect early stages of specific conditions. Currently, clinical studies are mainly based on subjective, visual assessment, with …
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Characterization of catalyst pellets using NMR and MRI: MRI, diffusion and relaxation measurements of liquid imbibed in alumina and titania extrudates
… methods, in particular the estimation of the tortuosity via the bulk porosity, but also to provide information about whether these characteristics are uniform throughout the pellet or whether there are heterogeneities introduced by the manufacturing process. Using the insights gained into mass …
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Image-Based Quantification and Coupled PNM-FEM of Architecture, Deformation, and Fluid Dynamics in Biological Porous Media Under Mechanical Loading
… as porosity, pore connectivity, pore size, and tortuosity, vary with tissue type and states, and these parameters influence the mechanical properties, like stiffness and permeability. Load-bearing soft tissues, such as the meniscus, display multilayered ECM architectures with graded mechanical …
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Microstructural and fluid transport properties of potatoes during frying
… time was also observed to have an effect on tortuosity, which is an important microstructural transport property. Tortuosity was measured by path length ratio method from 3D data sets obtained from image analysis. A linear inverse relationship was observed between porosity and tortuosity …
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Three-Dimensional Reconstruction of Marine Clay Nano- and Microstructure By Transmission Electron Microscopy: Analysis of Fabric and Pore Network
… pore orientation and volume, and pore network tortuosity.</p> <p>Flow pathway spreadsheet maps were created based on pore size and orientation. This technique allows tortuosity to be calculated for 3-D reconstructions while restricting porosity to a minimum boundary condition prior to …
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tle:43042b35-20c6-4eb2-a026-32c858dd4679:d6bd9758-527a-46cd-bfe2-c433766e8fca:1
… more stable and trustworthy methods, namely, tortuosity quantification and CFD analysis. Again, to ensure a comprehensive analysis of parameters, three different methods of determining geometric tortuosity have been implemented in this project. These methods each require varying amounts of …
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Mathematical Modeling of An Anode-Supported Micro-Tubular Sofc Powered by Ammonia
… properties (e.g. anode porosity, tortuosity and thickness) on the electrochemical properties of micro-tubular fuel cells.</p> <p> Our modeling results show that the polarization loss decreases with increasing operation temperature, which is attributed to enhanced activity of the …
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Theoretical and experimental investigations of passive and ultrasound-enhanced transdermal drug delivery
… to separately evaluate how the porosity, the tortuosity, and the hindrance factor of the aqueous pore channels that exist in the skin varied as the extent of skin perturbation due to simultaneous treatment of the skin with low-frequency ultrasound (US) and a chemical enhancer, the surfactant …
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MULTI-LAYERED, VARIABLE POROSITY SOLID- STATE LITHIUM-ION ELECTROLYTES: RELATIONSHIP BETWEEN MICROSTRUCTURE AND LITHIUM-ION BATTERY PERFORMANCE
… on effective conductivity, followed by geometric tortuosity. Notably, a template-based porous microstructure displayed a low tortuosity plane and a high tortuosity direction, as opposed to the more homogenous tape-cast porous microstructures. To evaluate the performance of these microstructures in …
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Numerical studies of flow in porous media using an unstructured approach
… of an electric and hydraulic definition of tortuosity to the Carman-Kozeny equation. The results of simulations using a number of computer generated porous structures indicate that an electrical tortuosity based on computed formation factor is well correlated with the tortuosity suggested by …
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Multiscale Tortuous Diffusion in Anion- and Cation-Exchange Membranes: Exploration of Counterions, Water Content, and Polymer Functionality
… local nm-scale dead ends, leading to changes in tortuosity as a function of water content, counterion type, and polymer structure. We furthermore parse tortuosity into two regimes, corresponding to nm-to-bulk and µm-to-bulk ranges, which reveal the importance of multi-scale morphological …
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Collagen Scaffolds for Tissue Engineering: The Relationship between Microstructure, Fluid Dynamics, Mechanics and Scaffold Deformation
… scaffolds had a larger percolation diameter. Tortuosity was used as a mathematical tool to characterise the interconnected pathways within each porous structure. The effect of the size of the region of interest (ROI) chosen and the size of the virtual probe particle used in the analysis on the …
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Investigation of Nanopore Confinement Effects on Convective and Diffusive Multicomponent Multiphase Fluid Transport in Shale using In-House Simulation Models
… and rock intrinsic properties (porosity and tortuosity factor) on predicting effective diffusion coefficient are investigated. First, a previously developed compositionally extended black-oil simulation approach is modified, and extended, to include the effect of large gas-oil capillary …
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Behavior of low-frequency sound waves in porous media
… characteristics considered include porosity, tortuosity, and flow resistivity.
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Acoustical characteristics of oil palm mesocarp fibres
… investigated namely flow resistivity, porosity, tortuosity, characteristic lengths, fibre diameter, air gaps and thickness of sample. The flow resistivity, tortuosity, fibre diameter, density of samples and characteristic lengths tend to increase with percentage of PU binder. But, porosity was …
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The retinal microvasculature as an early indicator of chronic disease risk in older populations
… kidney disease and increased retinal venular tortuosity, and between depression and reduced arteriolar tortuosity were identified, showing the potential clinical utility for identification of those at increased disease risk and possible intervention targets. No evidence of association between …
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Quantifying soil reinforcement by fibrous roots
… population where differences in root hairs, tortuosity and lignin biosynthesis were previously identified by screening large numbers of mutants.The initial hypothesis was that root numbers and area would control shear reinforcement, this was tested by altering planting density in both …
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