Digital Commons Network^™

Boat Wake Attenuation Through Artificial Vegetation - A Case Study From Peche Island, Jamie Kathryn Lilly

Electronic Theses and Dissertations

The use of nature-based solutions and engineering ideas has sparked interest in the value of vegetated shorelines for protecting against erosion. However, there is a lack of field data, and more research is needed to understand how effective vegetation is in reducing the impact of wind waves and boat wakes. The difference in period between wind waves and boat wakes suggests that they may be attenuated differently, requiring further study to determine the optimal management design. The purpose of this study is to quantify the ability of artificial vegetation to attenuate boat wakes and calculate the drag coefficient for model …

Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey

Electronic Theses and Dissertations

Exoplanets represent a young, rapidly advancing subfield of astrophysics where much is still unknown. It is therefore important to analyze trends among their parameters to learn more about these systems. More complexity is added to these systems with the presence of additional stellar companions. To study these complex systems, one can employ programming languages such as Python to parse databases such as those constructed by TESS and Gaia to bridge the gap between exoplanets and stellar companions. Data can then be analyzed for trends in these multi-star exoplanet systems and in juxtaposition to their single-star counterparts. This research was able …

Mechanism And Kinetics Of Photocatalytic Partial Oxidation Of Methane On Single Site Mox Reaction Centers., Clint Evrard

Electronic Theses and Dissertations

Single-site transition-metal doped photocatalysts are a class of materials in which small transition-metal oxide clusters are embedded onto the surface of zeolites, graphene, and bulk semiconductors. Experimental findings demonstrate that VO4, CrO4, NbO4, and WO4 clusters embedded on an MCM- 41 mesoporous amorphous SiO2 are effective photocatalysts for oxidative reactions. The selective direct partial oxidation of methane (POM) to form methanol is essential for efficiently utilizing natural gas. Photocatalytic methane oxidation has advantages over traditional thermal catalysis as it can be deployed at small-scale facilities to reduce methane release into the atmosphere due to flaring potentially. Our work has aimed …

Assessing The Effectiveness Of A Tool For Classifying And Assessing Student Energy Diagrams In Pre- And Post-Covid-19 Instruction, Michael Dudley

Electronic Theses and Dissertations

Energy is a broad concept that is used to interpret and understand scientific phenomena, and appears throughout the Next Generation Science Standards (NGSS) at all grade levels and across disciplines. The NGSS specifies no single approach for energy instruction, and makes use of different energy metaphors, often within individual standards. Gray, et al. (2019) created a checklist (the “Gray Checklist”) to identify whether or not a diagram exhibits evidence of core constituent ideas that align to the energy model of the NGSS. This study used the Gray Checklist to find trends in student energy diagrams that were produced during a …

New Methodologies For Examining And Supporting Student Reasoning In Physics, John C. Speirs

Electronic Theses and Dissertations

Learning how to reason productively is an essential goal of an undergraduate education in any STEM-related discipline. Many non-physics STEM majors are required to take introductory physics as part of their undergraduate programs. While certain physics concepts and principles may be of use to these students in their future academic careers and beyond, many will not. Rather, it is often expected that the most valuable and longlasting learning outcomes from a physics course will be a repertoire of problem-solving strategies, a familiarity with mathematizing real-world situations, and the development of a strong set of qualitative inferential reasoning skills.

For more …

The Temporal Conatus And The Problem Of Motion From Eternity, David Harmon

Electronic Theses and Dissertations

Spinoza’s theory of persistence is articulated through the conatus (EIp7) and the ratio of motion and rest (EIIp13). Section I explores Spinoza’s usage of “motion,” and illustrates that the conatus is essentially temporal. From this claim and Spinoza’s conception of eternity, the problem arises. I explain this as a contradiction between Natura naturata and Natura naturans. Section II features an evaluation of the potential acosmist solution and reveals how it contradicts other Spinozistic commitments. I construct an alternative solution in Section III. Temporal passage is not an adequate idea for Spinoza. However, Spinoza considers duration to be a feature of …

Investigation Of Narrow Bipolar Events In Mississippi Thunderstorms, Sampath Asiri Bandara

Electronic Theses and Dissertations

In the first part of the study FA and Log-RF data were used to examine low-altitude (<8.0 km) negative NBEs (NNBEs) to see how many -CG flashes were initiated by NNBEs. Out of 686 -CG flashes only 33 (5%) flashes were initiated by an NNBE. These NNBEs occurred at an average altitude of 6.2 km had average amplitude (range-normalized amplitude to 100 km) of 0.4 V/m and had average VHF (Log-RF) power of 130 W. Since the low-altitude NNBEs were substantially weaker than positive NBEs that initiate intracloud (IC) flashes it is hypothesized that -CG flashes are easier to initiate than IC flashes. The second part of the study investigated the properties of 201 positive NBEs (+NBEs). The +NBEs were classified in two ways: into Types A-D [Karunarathne et al. 2015] and into three different groups: Isolated Not-isolated and IC flash-initiator or INBE [Wu et al. 2014]. The average VHF (Log-RF) power of NBEs within the A-D categories were 1.9 4 9.8 and 13.2 kW respectively while the powers for the Isolated Not-isolated and INBE categories were 10.1 4 and 10.1 kW respectively. The third study considered 34 NBEs that occurred close in space and time to each other: 13 pairs of NBEs one group of three +NBEs and one group of five +NBEs. The NBEs were overlaid on radar data of the parent thunderstorms. The data indicate that the individual NBEs in each group initiated in separate intense electric field regions of small extent rather than in a single large-scale electric field region. This dissertation investigates Narrow Bipolar Events (NBEs) which are a type of short-duration (10- 30 µs) lightning discharge. The study primarily used data from NBEs collected in 2016 at seven sensor sites within 50 km of Oxford Mississippi USA. Each sensor site had three electromagnetic antennas called Fast Antenna (FA) dE⁄dt and Log-RF with bandwidths of 0-2.5 MHz 0-1.0 MHz and 186-192 MHz respectively. NBEs are often isolated from other lightning events in thunderclouds but they sometimes initiate negative cloud-to-ground (-CG) and intracloud (IC) lightning flashes or they can occur during these flashes.

Investigating Student Understanding Of Vector Calculus In Upper-Division Electricity And Magnetism: Construction And Determination Of Differential Element In Non-Cartesian Coordinate Systems, Benjamin Schermerhorn

Electronic Theses and Dissertations

Differential length, area, and volume elements appear ubiquitously over the course of upper-division electricity and magnetism (E&M), used to sum the effects of or determine expressions for electric or magnetic fields. Given the plethora of tasks with spherical and cylindrical symmetry, non-Cartesian coordinates are commonly used, which include scaling factors as coefficients for the differential terms to account for the curvature of space. Furthermore, the application to vector fields means differential lengths and areas are vector quantities. So far, little of the education research in E&M has explored student understanding and construction of the non-Cartesian differential elements used in applications …

Echoes Of The Past: The Effect Of Background Experience On Far Transfer, Graham H. Hummel-Hall

Electronic Theses and Dissertations

Far transfer is the application of knowledge learned in one setting to a problem in a very different setting. This multi-method study looked at far transfer in humans and whether it could be facilitated, inhibited, or remain unaffected by the number of courses or years a student at a university spent learning about the subject matter of the knowledge being transferred. Through quantitative and qualitative analysis of pretest and post-test data from an introductory undergraduate earth science course, I found that students with more physical science background experience more frequently engaged in successful and accurate transfer of physics information to …

Mississippians In Physics: Perspectives And Practice In A Search For Physics Excellence, Paul D. Rogers

Electronic Theses and Dissertations

This mixed-method study represents a broad evaluation of the physics views of Mississippi physics students and physicists, along with an analysis of graduate school data, in a search for answers which might improve physics education in Mississippi. Descriptive statistics were calculated using data from eight graduate degree programs (from Fall 2003 through Full Summer 2012) at the University of Mississippi. This was done to find the percent of graduate degrees in each degree program which were awarded to in-state residents. It was found that of the eight University of Mississippi graduate degree programs in the study, two programs awarded a …

Synthesis, Characterization, And Electronic Properties Of Novel 2d Materials : Transition Metal Dichalcogenides And Phosphorene., George Anderson

Electronic Theses and Dissertations

Scaling electronic devices has become paramount. The current work builds upon scaling efforts by developing novel synthesis methods and next generation sensing devices based on 2D materials. A new combination method utilizing thermal evaporation and chemical vapor deposition was developed and analyzed to show the possibilities of Transition Metal Dichalcogenide monolayers and heterostructures. The materials produced from the above process showed high degrees of compositional control in both spatial dimensions and chemical structure. Characterization shows controlled fabrication of heterostructures, which may pave the way for future band gap engineering possibilities. In addition, Phosphorene based field effect transistors, photodetectors, and gas …

Student Application Of The Fundamental Theorem Of Calculus With Graphical Representations In Mathematics And Physics, Rabindra R. Bajracharya

Electronic Theses and Dissertations

One mathematical concept frequently applied in physics is the Fundamental Theorem of Calculus (FTC). Mathematics education research on student understanding of the FTC indicates student difficulties with the FTC. Similarly, a few studies in physics education have implicitly indicated student difficulties with various facets of the FTC, such as with the definite integral and the area under the curve representation, in physics contexts. There has been no research on how students apply the FTC in graphically-based physics questions.

This study investigated student understanding of the FTC and its application to graphically-based problems. Our interest spans several aspects of the FTC: …

Identifying Productive Resources In Secondary School Students' Discourse About Energy, Benedikt Walter Harrer

Electronic Theses and Dissertations

A growing program of research in science education acknowledges the beginnings of disciplinary reasoning in students’ ideas and seeks to inform instruction that responds productively to these disciplinary progenitors in the moment to foster their development into sophisticated scientific practice. This dissertation examines secondary school students’ ideas about energy for progenitors of disciplinary knowledge and practice. Previously, researchers argued that students’ ideas about energy were constrained by stable and coherent conceptual structures that conflicted with an assumed unified scientific conception and therefore needed to be replaced. These researchers did not attend to the productive elements in students’ ideas about energy. …

Dangerous Instincts, Kirsten Holt

Electronic Theses and Dissertations

Dangerous Instincts is a collection of poems unified thematically by recurring and interstitial questions of the wilderness, the natural sciences - particularly astrophysics - the occult, and the mythic universe. These poems explore the mystical implications of the natural world and its meaning in the aesthetic consciousness, particularly in a highly secular century. Implied is the poet’s selfdiscovery and search for the divine. The collection emerges, not simply as interpretation, but a means of coming to terms with the fear of and compulsion to question the universe, and through those questions find illumination in the ordinariness of lived life and …

Mirrors And Vanities, Leslie Salas

Electronic Theses and Dissertations

Mirrors and Vanities is a multi-modal collection which showcases the diversity of working in long and short storytelling forms. Featured in this thesis are fiction, nonfiction, graphic narrative, and screenplay. Using unconventional approaches to storytelling in order to achieve emotional resonance with the audience while maintaining high standards for craft, these stories and essays explore the costs inherent to the subtle nuances of interpersonal relationships. The fiction focuses on the complications of characters keeping secrets. A husband discovers the truth behind his wife’s miscarriage. A girl visits her fiancé in purgatory. A boy crosses a line and loses his best …

Spin Pumping In Lateral Double Quantum Dot Systems, Sabine S. Pelton

Electronic Theses and Dissertations

Electron transport in single lateral quantum dot (QD) and parallel lateral double quantum dot (DQD) systems is modeled using semiclassical rate equations. The Zeeman effect, in conjunction with resonant tunneling, is used to select the spin of electrons involved in transport. We show adiabatic spin pumping by periodic variation of the systems' confining parameters, namely the quantum point contacts (QPCs) dictating the boundaries of the dots, and the gate voltage applied to each dot. The limitations of adiabatic spin pumping are subsequently examined by counting the average spin pumped per cycle when frequency and interdot capacitance are adjusted.

Resonance Raman Spectral Calculations Of Organic Semiconductor Molecules, Mohammadamin Torabi

Electronic Theses and Dissertations

Organic semiconductors have received a great deal of attention in recent years due to their optoelectronical properties and their potential applications in industry. In this thesis, resonance Raman calculations of a family of organic semiconductor dyes: pery-lene tetracarboxylic diimides (PTCD) derivatives, are presented. Also the UV/vis, infrared and normal Raman spectra, structures and molecular orbitals, excitation ener- gies, dipole moments, (hyper) polarizabilities and charge population analyses of these molecules are calculated. The calculations in this thesis are performed using a Time- Dependent Density Functional Theory (TDDFT) method, and for that, the Amsterdam Density Functional program package (ADF2009) is used. The …

String Theory And Our Relationship With Nature: The Convergence Of Science, Curriculum Theory, And The Environment, Virginia Therese Bennett

Electronic Theses and Dissertations

Curriculum Theory affords us the opportunity to examine education from a multitude of directions. This work takes advantage of that opportunity to explore the relationships between science, nature, and curriculum using string theory and our ideas about the environment as a backdrop. Both the energy and multiple possibilities created by strings and the rich history leading up to the theory help to illustrate the many opportunities we have to advance discussions in alternative ways of looking at science. By considering the multiple dimensions inherent in string theory as multiple pathways and interweaving metaphors from Deleuze and Guattari, Michel Serres, and …

3+1 Dimensions, Henry (Duke) Oursler

Electronic Theses and Dissertations

This Paper discusses the artwork produced for this thesis 3+1 Dimensions The paper discusses the works from an historical and theoretical perspective, focusing in particular on my influences which come from the larger scientific discipline of Quantum Mechanics. Connections are also made from the personal psychological perspectives of people and events that have had some impact on me personally. The paper will also discuss the sculptures individually and their connection to quantum physics as well any metaphorical content.

Excitation And Ionization Of 6li Ions Following Beta-Decay Of 6he., Eva Schulhoff

Electronic Theses and Dissertations

6He beta-decays into 6Li causing an electronic rearrangement of the final 6Li atom. The calculations involve expanding the initial state of 6He in terms of a complete set of final states of 6Li. Correlated Hylleraas-like wave functions were used to create a pseudospectrum, which spans both the bound and continue states of 6Li. The sudden approximation with neglected recoil was used. Starting from the 1 1S1 and 2 3S1 initial configurations, the transitions to the final 6Li bound states, as well as the total probabilities of single and double ionization were calculated. The transition probabilities to bound states were compared …

Development Of A Coaxial Electron-Laser Beam Collision Experiment, Justin Teeuwen

Electronic Theses and Dissertations

An electron optical system which propagates an electron beam coaxially with a laser was designed, developed and tested. Greatly improved signal rates were obtained when excitation of various target species under electron impact was studied. Measurements of excitation in nitrogen, specifically the (0,0) second positive band of N2 and (0,1) first negative band of N2 are made and compared with well-known previous results to calibrate the system. Emission cross section measurements were made by direct excitation of a number of argon transitions, including the 3p5 4p [1 1/2] (J=1) -> 3p5 4s [1/2] (J=0) transition. Comparison with previous results showed …

Optical Properties Of Nanostructures And Applications To Surface-Enhanced Spectroscopy, Daniel Ross

Electronic Theses and Dissertations

Metallic nanoparticles, in particular silver and gold nanostructures, are at the centre of the development of plasmon enhanced optical signals. There is a flurry of activities in the fabrication and testing of these nanostructures, especially in surface enhanced Raman scattering (SERS) and surface enhanced-infrared absorption (SEIRA), the two branches of surface-enhanced vibrational spectroscopy. The need to develop an understanding of this general subject matter for practicing spectroscopists cannot be questioned. This work is a unique undertaking intended to examine some of the elements that give rise to surface enhanced spectroscopy. The optical properties of nanoparticles are discussed in detail, beginning …

Quantum Phase Transition In Triple Quantum Dot System And Its Consequences On Transport, Behnam Javanparast

Electronic Theses and Dissertations

In this thesis, possibility of quantum phase transition in systems composed of quantum dots will be studied. We also investigate the consequence of this phase transition on transport. We particularly consider a triple quantum dot system (three quantum dots sitting on the corners of an equilateral triangle) coupled to three leads symmetrically. To probe quantum phase transition we utilize slave-boson mean-field theory and to investigate transport properties we use scattering formalism. We detect a competition between Kondo and non-Kondo regime in this system. This competition affects transport in a way that conductance and noise will become zero when the non-Kondo …

Real Time Physical Analysis Of Consolidation Process For Low Pressure Gas Dynamic Spray, Mark Lubrick

Electronic Theses and Dissertations

The gas dynamic spray process is studied via acoustic methods with the main focus being on developing an online system to monitor the process as it occurs. Elastic modulus measurements of the coatings are determined from the sound velocity and porosity. The resulting data is than compared against a minimum contact area model that is developed to describe the bonds that are formed between particles. The results show a good fit to the theoretical considerations of the model. Different transducer designs are considered leading to the use of a multi-element flat transducer for the online monitoring. Online measurements show that …

The Problem Of Substantial Generation In Aristotle's Physical Writings, Michael Ivins

Electronic Theses and Dissertations

This dissertation explores the relation between Aristotle's account of the generation of substances and his attempt to lay the foundations for his natural philosophy. The central question concerns the injunction posed by the Eleatic philosophers to the study of nature on the basis of the principle "ex nihilo nihil" which they formulated into argument against the intelligibility of nature. Aristotle's Physics begins with a sustained attempt to defeat the Eleatic prohibition by demonstrating that change in general can be understood once a few principles are established. My reading of the arguments that constitute Aristotle's refutation of the Eleatics and the …

A Descriptive Framework For The Problem-Solving Experiences Of Physics Students, Sherry Savrda

Electronic Theses and Dissertations

This study investigated the applicability of a general model of physics students' problem-solving experiences that suggests there are four dynamic factors affecting the problem-solving process: categorization, goal interpretation, resource relevance, and complexity. Furthermore, it suggests an overarching control factor called stabilization, which describes the inter-relatedness of the other factors over the problem-solving process. Think-aloud protocols of problem-solving experiences were used to investigate the model. Results of the study showed that conceptual resources had a significant impact on the success of problem-solving attempts. Participants who exhibited a lack of understanding of physics concepts were less likely to check their work, use …

Molecular Studies Using Resonance Enhanced Multiphoton Ionization., Jeffrey Matos

Electronic Theses and Dissertations

Nitric oxide was studied using the techniques of laser induced fluorescence and resonance enhanced multiphoton ionization. A supersonic expansion beam consisting of nitric oxide and argon gas was crossed with a laser beam. The A2Sigma+ state of nitric oxide was used as an intermediate in the ionization process. Total fluorescence from the A2Sigma + state of nitric oxide was collected while the laser source was scanned from 225.5 nm to 226.9 run to produce an excitation spectrum. Time-of-flight mass spectra of nitric oxide, argon, and nitrogen were collected to verify the ions produced and to calibrate a newly constructed time-of-flight …

On Hawking Radiation And The Casimir Effect., Darragh Rooney

Electronic Theses and Dissertations

The purpose of this thesis is to understand the quantum vacuum in curved space-time by comparing the phenomenon of Hawking radiation with the Casimir effect. I begin with an exposition on the semiclassical approximation, as yet our best framework for understanding the curved vacuum, with additional preliminaries regarding the nature of particles and vacua in general. I discuss the Schwarzschild black hole, and derive the Hawking particle flux. Hawking radiation is viewed as a kinematical effect, which I compare to the case of mirrors moving in flat space-time. I move on to the Casimir effect: I discuss the classic case …

Hardness Characteristics Of Cobalt/Chromium And Nickel/Chromium By Electrodeposition Or Electroless Deposition., Wei Chen

Electronic Theses and Dissertations

This work is a report on the study of hardness characteristics of Nickel and Cobalt thin films with and without chromium powder. The coatings are prepared by electrodeposition or electroless deposition [1]. The dispersed phase was Cr particles in a concentration of 50 to 100 mg/l added in the electrolyte, magnetically stirred in 400 rev./min.-1 for a few minutes then stopped for a certain period of time. Purpose of this is to let bigger particles settle down on the bottom and only the finest particles floating in the bath evenly. It is shown that many factors contribute to the quality …

High Precision Theoretical Study Of The Hydrogen Ion., Mark Michael Cassar

Electronic Theses and Dissertations

A study of the hydrogen molecule-ion H+2 is presented. The purpose is to show that a carefully modified, doubled basis set in the standard Hylleraas coordinates provides an excellent, yet straightforward, description of this ion without recourse to approximation methods. Three non-linear parameters are used so that distance scales may be set independently for all three radial coordinates r 1, r2 and r12. Vibrational modes are effectively accounted for by including only high powers of the inter-proton coordinate r12. High precision variational calculations are carried out for the 1 1 S ground state, and the first two excited states---2 1S …