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.
Results
Showing 1 to 20 of 39 for “"particle dispersion"”.
-
Particle dispersion in isotropic turbulence and unsteady particle dynamics at finite Reynolds number
A solution to particle dispersion in an isotropic turbulence under Stokes drag, Basset force and gravitational force is obtained in closed form using the independence approximation. The Basset force has no effect on the fluid velocity structure seen by the particles or the long-time particle …
-
Large Eddy Simulations of Particle Dispersion and Deposition in a Turbulent Square Duct Flow
Deposition of particles in a square duct is the focus of the second set of simulations. Ten particle response times are studied. Simulations are carried out using one-way coupling as well as select cases using two- and four-way coupling. A particle-particle collision algorithm has been developed. …
-
A Stochastic Lagrangian Model for Non-Gaussian Fluid Turbulence and Its Application to Describe Particle Dispersion in a Channel
Stochastic Lagrangian simulations are computationally efficient, since the equations to be solved are not partial differential equations as in the direct simulations. They are ideally suited for parallel computers. The stochastic model is about 120 times faster than the DNS on a single processor on …
-
Effects of silica nanoparticle surface treatment and average diameter on the physical and mechanical properties of poly(dimethylsiloxane)-silica nanocomposites
… thesis was to quantify the effects of silica nanoparticle surface treatments and average silica nanoparticle diameter on various macroscopic properties of poly(dimethylsiloxane)-silica nanocomposites, specifically stiffness, wettability, and permeability to organic solvents. …
-
Formation of Meso-Structured Multi-Scale Porous Titanium Dioxide by Combined Soft-Templating, Freeze-Casting and Hard-Templating Using Cellulose Nanocrystals
… freeze-casting for the preservation of particle dispersion found in suspension, and hard-templating by the use of cellulose nanocrystals (CNCs) as sacrificial material. A systematic study was conducted wherein three synthesis parameters (water content, alcohol solvent content, and drying …
-
Comparing Turbulent Dispersion Models for RANS Simulations of Particle-Laden Flows
The ingestion of sand-particles into turbomachinery decreases their longevity and perfor- mance and can even lead to failure. To address these problems, studying particle-laden flows is of high interest in the field. Due to their low computational cost, RANS simulations remain the preferred method …
-
The Surface Reaction Mechanisms of Beta-Diketones on Transition Metal Surfaces Including Applications to Metal Thermal Chemical Vapor Etching and Heterogeneous Catalyst Particle Redispersion
… supported Pd catalysts in an attempt to alter Pd particle dispersion. Low-temperature redispersion of a sintered 5% Pd/gamma-alumina catalyst was most successful via exposure to oxygen and acetylacetone at ∼560 K for 8 hours. A bimodal distribution of CO desorption states was achieved, at 405 …
-
Simulation of a Singular Cough Event in an Enclosed Breakroom
… The results are analyzed to determine important particle behavior in the breakroom. It was found that the position of the initial cough with respect to the vents was significant. In particular, when the cough was nearer to the inlet vent, where turbulence was higher, the particles dispersed …
-
Tidal dynamics and dispersion around coastal headlands
… of shallow tidal currents and tide-induced dispersion are investigated around coastal headlands that have alongshore length scales that are comparable to or less than the tidal excursion. Depth-averaged shallow water equations forced by oscillatory flow are solved numerically for Gaussian …
-
Measurement of electron-electron interactions in one dimension with tunnelling spectroscopy
… instead of studying the behaviour of individual particles, it is better to describe the emergent phenomena of the whole system, known as quasiparticles. These are collective modes of excitations born out of particle-particle interactions, which resemble the constituent single particles, albeit …
-
Kinematic simulation of turbulent flow and particle motions
… are 'many different techniques for modelling particle dispersion in turbulent flow (e.g. K-theory and Random Flight) but they make assumptions about the fluid-particle interaction and require empirical coefficients. Theoretical work on the motion of bubbles and varticles in idealised flows has …
-
Processing Approaches for Maintaining Multifunctionality in Advanced Thermoplastic Composites
… is not trivial, as the functionality of the particles must be retained during production, and the polymer matrix and particle interactions can often reduce the effectiveness of the final product. When fundamental principles, including thermodynamic and hydrodynamic considerations, are …
-
Nano-Silicon/graphene Composite Anodes For Enhanced Performance Lithium Ion Batteries
… material, graphene, to form a standalone Si nanoparticle/graphene composite anode and implement the electrode design improvements via (1) optimized particle dispersion, (2) modifications of graphene and C coatings; and (3) the use of a conversion active material in the form of SiNx. Imaging, …
-
The effect of particle size distribution on the rheology of ultrafine coal-water slurries
… at optimum additions determined to maximize particle dispersion. As a result of this investigation, it has been found that the maximum solids loading for ultrafine coal slurries ranges from 55 to 60 percent by weight as compared to 70 to 75 percent solids reported for coarser slurries. It was …
-
Modeling moderately dense to dilute multiphase reacting flows
… on the grid but they are treated as point-particles that interact with the background continuum. A consistent multiphase formulation is developed in this work that can be used to model either resolved or unresolved MPEs over a complete range of volume fractions. One phase is always modeled …
-
Mesometeorological modelling and trajectory studies during an air pollution episode in the lower Fraser Valley, British Columbia, Canada
… the modelling day was explored with a Lagrangian particle dispersion model. Specifically, forward trajectories were calculated for particles released at various locations in the Lower Fraser Valley and at different times. A systematic qualitative and quantitative model evaluation with the …
-
Transient Liquid Phase Diffusion Bonding of Magnesium Alloy (Mg-AZ31) to Titanium Alloy (Ti-6Al-4V)
… at the joint. The effect of Cu nano-particles in the coatings was found to decrease the eutectic zone width and this resulted in an increase the shear strength of the joints. The highest shear strength of 69 MPa was possible with bonds made using coatings containing Cu nano-particle …
-
Improving Impact Properties of Novatein through Polymer Blending and Reactive Extrusion
… was blended with either elastomeric core-shell particles, polyethylene (PE), or biodegradable polybutylene adipate-co-terephthalate (PBAT) using twin-screw extrusion to allow for sufficient mixing and residence time for chemical interactions or reactions to form. Materials were characterized for …
-
Design and Construction of Smart Structures for Technical Textiles
… work on the integration of Carbon Black particles and Carbon Nanotubes into Nylon 6.10 and extrude a monofilament using a standard melt spinning technique. Although the resultant yarns manufactured did not display the properties required, analysis of the CB and CNT properties, the …
Page 1 of 2