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 22 for “"Phase Diffusion"”.
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Droplet Dispersion in a Turbulent Pipe Flow (Particle, Two-Phase, Diffusion)
The radial dispersion of water droplets injected into a turbulent pipe flow of air has been investigated. The eddy diffusivity, (epsilon)(,p), mean-square fluctuating velocity, v(,p)('2), and Lagrangian integral time scale, (tau)(,p), of droplets with diameters of 50, 90, and 150 (mu)m are …
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Transient Liquid Phase Diffusion Bonding of Magnesium Alloy (Mg-AZ31) to Titanium Alloy (Ti-6Al-4V)
… fusion welding techniques. Transient liquid phase (TLP) bonding of magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al- 4V was performed and different interlayer types and configurations were used to facilitate joint formation. The joining of these alloys using Ni foils was successful at a …
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Laser Metallization And Doping For Silicon Carbide Diode Fabrication And Endotaxy
… the bulk silicon carbide by laser-induced solid phase diffusion (LISPD) can be explained by considering the laser enhanced substitutional and interstitial diffusion mechanisms. Nitrogen and Trimethyaluminum (TMA) are used as dopants to produce n-type and p-type doped silicon carbide, …
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Spectroscopic Measurements of the Combustion of Aluminum and Aluminum-Based Energetic Material Particles Using a Heterogeneous Shock Tube
… particles below 10 mum do not burn with the gas-phase diffusion flame observed in larger (>20 mum) sizes, but rather with reactions occurring very close to the particle surface. These particles thus have lower combustion temperatures and longer burn times than would be expected under correlations …
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Effect of Design Parameters and Intercalation Induced Stresses in Lithium Ion Batteries
… (Cu CC) substrate. The model solves for diffusion of lithium in Si NW, stress generation in the Si NW due to chemical and elastic strain, stress generation in the Cu CC due to elastic strain, and volume expansion in the Si NW and Cu CC geometries. The evolution of stress components, i.e., …
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Feedback control of complex oscillatory systems
… a noisy limit cycle oscillator in the context of phase dynamics is evaluated by the phase diffusion constant, which is in its turn proportional to the width of the spectral peak of oscillations. Many chaotic oscillators can be described within the framework of phase dynamics, and, therefore, their …
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Quantum coherence and magnetism in bosonic and fermionic gases of ultracold atoms
… interactions provides strong evidence for a phase transition to a ferromagnetic state. Our observations imply that itinerant ferromagnetism of delocalized fermions is possible without lattice and band structure, and our data validate the most basic model for ferromagnetism introduced by …
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Pressureless Densification of Alumina - Titanium Diboride Ceramic Matrix Composites
The research focus was to determine diffusion mechanisms responsible for densification behavior of SHS produced Al2O3/TiB2 Ceramic Matrix Composites (CMCs). Previous research has shown SHS produced Al₂O₃/TiB₂ composites exhibited unique microstructural properties that contributed to high strength, …
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Synchrotron radiation-based characterization of GaN- based MQW structures and strongly correlated materials
… where interpreted within the framework of vapor-phase diffusion and surface-migration effects during the metalorganic vapor phase epitaxial growth. The relatively short diffusion length of group- III precursors and growth enhancement, due to facet migration was found to have significant effects …
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Modeling Diffusion-Controlled Emissions of Volatile Organic Compounds From Layered Building Materials
… the emission of VOCs from building materials. Diffusion has been shown to control the rate of mass transfer within certain types of building materials. The primary objective of this research is to develop a fundamental diffusion-based model for single and double layer building materials. The …
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Broad-spectrum antivirals against coronavirus using natural products and drug repurposing strategies
… revealed limited antiviral efficacy, vapour-phase diffusion of the oils significantly reduced coronavirus infectivity. Chemical analysis identified volatile terpenes and phenolic compounds—particularly TQ—as key antiviral constituents. These volatile agents exhibited selective activity …
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THERMAL MODELS OF LITHIUM-ION CELLS AND BATTERIES
… obtained from curve fitting. To solve the solid phase diffusion equation in single particle models, a new approximated eigenfunction solution was developed; and with this method, the solution of the partial differential equation in spherical particles can be accurately approximated by only a few …
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Phenomenology And Experimental Observations In High Temperature Ternary Interdiffusion
… to extract composition dependent ternary interdiffusion coefficients from a single diffusion couple experiment is presented. The calculations involve direct determination of interdiffusion fluxes from experimental concentration profiles and local integration and differentiation of Onsager's …
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Evaluating Surface Mechanisms for Catalytic Combustion Of H2 and CH4 on Pd Catalysts
… model for a catalytic channel flow with intra-phase diffusion in the porous washcoat support. Mechanisms for low temperature (< 250ºC) combustion of H2 under excess O2 and for relatively high temperature (> 400ºC) CH4 combustion under excess O2 have been developed and evaluated by comparison of …
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Physics-based and data-driven modeling of multi-active material electrode batteries
… capable of accounting for parallel reactions and diffusion pathways, phase transformations, multi-scale heterogeneities, and interactions between individual active materials. However, existing open-source battery simulation frameworks based on porous electrode theory are tailored for …
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Coherence and synchronization of noisy-driven oscillators
In the present dissertation paper we study problems related to synchronization phenomena in the presence of noise which unavoidably appears in real systems. One part of the work is aimed at investigation of utilizing delayed feedback to control properties of diverse chaotic dynamic and stochastic …
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Modeling VOCs Emissions from Multi-layered Structural Insulated Panels(SIPs)
… independently measuring C0 (the initial material-phase concentration), D (the material-phase diffusion coefficient), K (the material/air partition coefficient) and then predicting the emission rate a priori using a fundamental mass-transfer model We now wish to generalize this approach and use it …
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Physiological and molecular determinants of the Chlamydomonas reinhardtii pyrenoid
… despite frequent low availability and limited diffusion of CO2 in the aquatic milieu, and low affinity for CO2 by the primary carboxylating enzyme, Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Many eukaryotic algae, and a single group of land plants, the hornworts, have an …
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Modeling Diffusion-Controlled Emissions of Volatile Organic Compounds from Building Materials
… mechanisms governing emissions behaviors, diffusion appears to be one of the most significant. The primary objective of this research was to demonstrate that the VOC emissions source behavior of a diffusion-controlled homogenous building material could be predicted using a mechanistic …
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Droplet and Particle Dynamics in Aerosol Reactors and Environmental System
… was modified to additionally account for gas phase transport of monomers and polymerization reaction inside the droplet. The effect of different reactor conditions was examined on the average chain length of polymers in synthesized PEDOT nanoparticles as it directly affects their conductivity. …
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