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Nonlinear Waves On A String With Inhomogeneous Properties, Robert Arredondo
Nonlinear Waves On A String With Inhomogeneous Properties, Robert Arredondo
Doctoral Dissertations
Nonlinear waves on an infinite string with a rapid change in properties at one location are treated. The string is an idealized version of more complex configurations in both fluids and solids. This idealized version treats the property change as an interface with a discontinuity in properties. Packets of waves are then considered with a reduced model, here a set of nonlinear Schr¨odinger (NLS) equations. The stress and the displacement must both be matched at the interface, resulting in dynamic and kinematic interfacial conditions. The dynamic condition produces an inhomogeneous effect that cannot be treated successfully with separation-of-variables. This inhomogeneity …
The Directed Molecular Self-Assembly Of A Novel Pentacene Derivative On Gold Surfaces: An Experimental And Computational Study, Amanda Margaret Larson
The Directed Molecular Self-Assembly Of A Novel Pentacene Derivative On Gold Surfaces: An Experimental And Computational Study, Amanda Margaret Larson
Doctoral Dissertations
Understanding electronic devices down to the atomic scale is essential for the development of novel organic molecule based nanotechnologies. Utilizing scanning tunneling microscopy (STM), new organic molecules can be imaged to understand their structural and electronic properties at the molecular level. 5,6,7-trithiapentacene-13-one (TTPO) is a promising organic semiconductor with potential applications in high temperature photovoltaic devices as an electron donor. My STM investigation of TTPO on the close-packed stepped Au(788) surface reveals interesting nanoscale surface structures ranging from molecular chains at low coverage to an ordered self-assembled monolayer. I have utilized density functional theory (DFT) to further probe this unique …
A Study Of Interplanetary Shock Geoeffectiveness Controlled By Impact Angles Using Simulations And Observations, Denny Oliveira
A Study Of Interplanetary Shock Geoeffectiveness Controlled By Impact Angles Using Simulations And Observations, Denny Oliveira
Doctoral Dissertations
In this dissertation, we study the influence of interplanetary (IP) shock impact angles in the IP shock geoeffectiveness focusing on simulations and observations. In our simulations, we use OpenGGCM global MHD code to study the nightside magnetospheric, magnetotail, and ionospheric responses to IP fast forward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30$^o$ in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along the …
The Study Of Ionospheric Response To Precipitation Using Sounding Rocket Observations, Ian James Cohen
The Study Of Ionospheric Response To Precipitation Using Sounding Rocket Observations, Ian James Cohen
Doctoral Dissertations
Understanding the role that the ionosphere plays in phenomena such as the development of auroral arcs and ion outflow is basic to the investigation of these processes and critical to the advancement of the broader study of magnetosphere-ionosphere coupling. Sounding rockets present an optimal platform for such studies, allowing low-cost access to altitudes that are difficult to reach by other means. Additionally, these measurements are key to validating current models and furthering understanding of the near-Earth space environment. This thesis highlights two particular rocket-borne instruments that measure electron populations in the ionosphere: the Electron Retarding Potential Analyzer (ERPA) and the …
A Supercell, Bloch Wave Method For Calculating Low-Energy Electron Reflectivity With Applications To Free-Standing Graphene And Molybdenum Disulfide, John Francis Mcclain
A Supercell, Bloch Wave Method For Calculating Low-Energy Electron Reflectivity With Applications To Free-Standing Graphene And Molybdenum Disulfide, John Francis Mcclain
Doctoral Dissertations
This dissertation reports on a novel theoretical and computational framework for calculating low-energy electron reflectivities from crystalline surfaces and its application to two layered systems of two-dimensional materials, graphene and molybdenum disulfide. The framework provides a simple and efficient approach through the matching of a small set of Fourier components of Bloch wave solutions to the Schrodinger Equation in a slab-in-supercell geometry to incoming and outgoing plane waves on both sides of the supercell. The implementation of this method is described in detail for the calculation of reflectivities in the lowest energy range, for which only specular reflection is allowed. …
The Synthesis And Characterization Of Iron Nanoparticles, Tyler Paul Bennett
The Synthesis And Characterization Of Iron Nanoparticles, Tyler Paul Bennett
Master's Theses and Capstones
Nanoparticle synthesis has garnered attention for technological applications for catalysts, industrial processing, and medical applications. The size ranges for these is in the particles nanostructural domain. Pure iron nanoparticles have been of particular interest for their reactivity and relative biological inertness. Applications include cancer treatment and carrying medicine to a relevant site. Unfortunately, because of their reactivity, pure iron nanoparticles have been difficult to study. This is because of their accelerated tendency to form oxides in air, due to the increased surface area to volume ratio. Using synthesis processes with polyphenols or long chain amines, air stable iron nanoparticles have …