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Solar Modulation Of The Cosmic Ray Intensity And The Measurement Of The Cerenkov Reemission In Nova’S Liquid Scintillator, Philip James Mason

Doctoral Dissertations

The NOνA (NuMI Off-axis electron neutrino Appearance) experiment is a long baseline neutrino oscillation experiment at Fermi National Accelerator Laboratory. Its purpose is to observe the oscillation of ν_μ (muon neutrino) to ν_e (electron neutrino) and to investigate the neutrino mass hierarchy and CP violation in the neutrino sector. Two detectors have been built for this purpose, a Near Detector 300 feet underground at Fermilab, and a Far Detector, on the surface at Ash River, Minnesota.

The completion of NOνA’s Far Detector in October 2014 enabled not only the recent measurement of neutrino oscillations, but an array of …

Thinking Nature, "Pierre Maupertuis And The Charge Of Error Against Fermat And Leibniz", Richard Samuel Lamborn

USF Tampa Graduate Theses and Dissertations

The purpose of this dissertation is to defend Pierre Fermat and Gottfried Wilhelm Leibniz against the charge of error made against them by Pierre Maupertuis that they errantly applied final causes to physics. This charge came in Maupertuis’ 1744 speech to the Paris Academy of Sciences, later published in different versions, entitled Accord Between Different Laws Which at First Seemed Incompatible. It is in this speech that Maupertuis lays claim to one of the most important discoveries in the history of physics and science, The Principle of Least Action. From the date of this speech up until the end …

Geometry And Thermodynamics Of Filament Bundles, Isaac Bruss

Doctoral Dissertations

In this dissertation I present a study of the geometry and energetics of bundles composed of flexible cohesive filaments. This is a general class of materials, both biological and artificial, existing across many length scales. The aim of this thesis is to investigate the interdependence between the 2D organization of filaments in a bundle’s cross section, and the 3D structure, with an emphasis on the twisting mode of deformation. First we present a model of filament contacts and interactions, which we employ in numerical simulations to study the connection between the ground state energies of constant-pitch bundles and their interior …

Electron Transmission Through Micrometer Sized Funnelshaped Tapered Glass Capillaries And Electron Micro-Beam Production, Samanthi Jayamini Wickramarachchi

Dissertations

The prime motivation of this work is to understand the fundamental transmission process of an electron beam through a funnel-shaped capillary taking into account its shape together with the energy, angular and time dependence of the transmitted electrons produce a microsized electron beam. The utilized capillaries had inlet/outlet diameters of 800/16 μm, 800/100 μm and lengths of 35 mm. Considerable transmission of 800 and 1000 eV electrons for tilt angles up to 1.5^o and only small transmission for 500 eV electrons was observed for the capillary with the smaller outlet diameter of 16 μm. Incident electrons with energies of …

Literatures Of Stress: Thermodynamic Physics And The Poetry And Prose Of Gerard Manley Hopkins, Thomas Mapes

English Dissertations

This dissertation examines two of the various literatures of energy in Victorian Britain: the scientific literature of the North British school of energy physics, and the poetic and prose literature of Gerard Manley Hopkins. As an interdisciplinary effort, it is intended for several audiences. For readers interested in science history, it offers a history of two terms – stress and strain – central to modern physics. As well, in discussing the ideas of various scientific authors (primarily William John Macquorn Rankine, William Thomson, P.G. Tait, and James Clerk Maxwell), it indicates several contributions these figures made to larger culture.

For …

Jam Tomorrow, Tim Glenn Boothe

Theses

These poems are filled with a concern for identity, sometimes leading the reader into the subconscious realm, or the realm of the muse. In this effort, a few of these poems journey back to childhood to relive images and icons from the 70s. The “Alice” poems delve into the subconscious and question the insanity of existence. Yet the bulk of the poems explore the many facets of love and relationships, conveying a sense of unending desire to be shackled and enslaved by emotion, bordering on obsession. And interspersed throughout, there are poems that reflect on psychoanalysis, physics, and ponder on …

Integrating Formative Assessment Into Physics Instruction: The Effect Of Formative Vs. Summative Assessment On Student Physics Learning And Attitudes, Chaiphat Plybour

Dissertations

Of many instructional strategies used to improve teaching and learning in science, formative assessment is potentially one of the most effective. A central feature is timely feedback during learning, giving students the opportunity to benefit and improve while also enabling teachers to adjust instruction to learner needs. By contrast, conventional assessment tends to be mostly summative, assigning point scores, grading and ranking students, and providing extrinsic motivation. For maximum effectiveness in enhancing learning, formative assessment should be designed into instruction from the start rather than being an add-on. This project comprised development, teaching, and research aspects. Two physics topic modules, …

Measuring The Hyperfine Splittings Of Lowest Energy Atomic Transitions In Rubidium, Benjamin D. Graber

Undergraduate Honors Thesis Projects

The goal of this experiment was to measure the hyperfine energy splittings of the ground to first excited state transitions in rubidium using saturated absorption spectroscopy. Using this technique, we measured these transition energy spectra by taking the difference of two photodiode outputs due to multiple beams of a single laser scanned over a range of frequencies and shone through a cell of Rb vapor. When the laser frequency was resonant with an atomic transition, photons of those frequencies were absorbed, leaving a dip in intensity of the beam measured at the photodiode. One of the two laser beams had …

Visualizing Relationships Between Related Variables: Improving Physics Education Through D3.Js Network Visualizations, Stephanie Friend

Liberal Arts and Engineering Studies

phiMap is a web application started by Cal Poly professors and students to aid professors in teaching physics. I developed Javascript visualizations for phiMap that serve to simplify the processes of both teaching and learning physics. These visualizations aim to present relationships between physics variables in an easy to understand manner, and they could eventually have a huge impact on physics education.

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

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

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

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

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. …

Science For Visually Impaired Students And Accessible Technology, Lydia M. Moreland

Theses, Dissertations and Capstones

Blind and visually impaired students need appropriate methods and accessible technology in order to compete and advance in learning the science concepts. The study investigated the attitudes, perceptions, and knowledge of assistive technology used by science teachers of the visually impaired from a Mid-Atlantic state and how they are incorporated in the classroom. The participant response gives notice to what forms of assistive technology are used in frequency, and the training and comfort level to use the assistive technology. The open responses stated themes of teachers needing more training in visual impairment college programs to use assistive technology to increase …

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 …

Using Computer Simulations As A Pre-Training Activity In A Hands-On Lab To Help Community College Students Improve Their Understanding Of Physics, Blanca Pineda

Doctoral Dissertations

The purpose of this study was to investigate the effectiveness of using computer simulations as a pre-training activity to a hands-on lab to improve students’ understanding of induction topics in physics. The computer simulation activity was compared to an overview presentation. Conceptual understanding and spatial ability were measured. A two-group descriptive repeated measures design was implemented with a convenience sample of 35 community college physics students in the Bay Area. Participants were randomly assigned to a simulation group (n = 17) or a presentation group (n = 18). A 30-item spatial ability assessment was given to all participants one week …

Spatiotemporally Periodic Driven System With Long-Range Interactions, Owen Dale Myers

Graduate College Dissertations and Theses

It is well known that some driven systems undergo transitions when a system parameter is changed adiabatically around a critical value. This transition can be the result of a fundamental change in the structure of the phase space, called a bifurcation. Most of these transitions are well classified in the theory of bifurcations. Among the driven systems, spatiotemporally periodic (STP) potentials are noteworthy due to the intimate coupling between their time and spatial components. A paradigmatic example of such a system is the Kapitza pendulum, which is a pendulum with an oscillating suspension point. The Kapitza pendulum has the strange …

Atmospheric Effects On Radar/Ladar Detection Of Seismic Activity, Michelle Frances Via

Browse all Theses and Dissertations

This thesis investigates how well ground vibrations can be detected at ladar or radar wavelengths and how the atmosphere may impact the observation of such activity. First understanding atmospheric hindrances at each of these wavelengths is helpful to prioritize by those yielding best transmission results. A prerequisite to the outdoor field experiment performed for this study involves analyzing atmospheric effects characterization at six probable wavelengths using the Laser Environmental Effects Definition and Reference tool (LEEDR) developed by the Air Force Institute of Technology's (AFIT) Center for Directed Energy (CDE). These wavelengths, selected from the shortwave infrared and microwave portions of …

Assessment Of The Applicability Of Terahertz Spectroscopic Breath Sensing Towards Monitoring Type 1 Diabetic Mellitus, Jessica Rose Thomas

Browse all Theses and Dissertations

Type 1 diabetes is a condition that cumulatively costs around $14.9 billion in medical expenses every year in the United States. Besides being costly, the monitoring of this disease is invasive, painful, and often embarrassing to the afflicted individual; blood and urine testing is currently the daily method of monitoring blood glucose and ketone levels in the body of type 1 diabetics. Though the use of these samples is standard, another avenue for possibly determining blood glucose has not been completely explored. With over 3000 chemicals reportedly found in exhaled human breath, biomarkers associated with this disorder and many of …

Dna-Nucleobase Guanine As Passivation/Gate Dielectric Layer For Flexible Gfet-Based Sensor Applications, Adrienne Dee Williams

Browse all Theses and Dissertations

The main goal of this dissertation was two-fold: first, to study and design a graphene-based transistor environmentally friendly by replacing a standard substrate and gate dielectric with different flexible/rigid and biodegradable films and secondly, to study their effects on graphene's charge carrier mobility. A thin film of deoxyribonucleic acid nucleobase purine guanine deposited by physical vapor deposition onto up to ten layers of graphene that were transferred onto various rigid and flexible substrates was characterized more thoroughly. Several test platforms were fabricated with guanine 1) as a standalone gate dielectric, 2) as the control and 3) as a passivation layer …