Physics Commons^™

Three-Dimensional Bedrock Channel Evolution With Smoothed Particle Hydrodynamics, Nick Richmond

Electronic Theses and Dissertations

Bedrock channels are responsible for balancing and communicating tectonic and climatic signals across landscapes, but it is difficult and dangerous to observe and measure the flows responsible for removing weakly-attached blocks of bedrock from the channel boundary. Consequently, quantitative descriptions of the dynamics of bedrock removal are scarce. Detailed numerical simulation of violent flows in three dimensions has been historically challenging due to technological limitations, but advances in computational fluid dynamics aided by high-performance computing have made it practical to generate approximate solutions to the governing equations of fluid dynamics. From these numerical solutions we gain detailed knowledge of the …

Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for a silicon photovoltaic device which incorporates a nanohair textured p-n junction. The silicon nanowires are etched into a silicon wafer, comprising an epitaxial p-layer on n-substrate, via metal-assisted chemical etching (MACE). The resulting nanowires contain p-n junctions that lie along the length of the vertical nanowires. This construct has the potential to increase the optical bandwidth of a silicon photovoltaic device by allowing a greater amount of short wavelength light to reach the junction. In addition, the MACE method of nanofabrication has the potential for decreasing …

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 …

Microwave Acoustic Saw Resonators For Stable High-Temperature Harsh-Environment Static And Dynamic Strain Sensing Applications, Anin K. Maskay

Electronic Theses and Dissertations

High-temperature, harsh-environment static and dynamic strain sensors are needed for industrial process monitoring and control, fault detection, structural health monitoring in power plant environments, steel and refractory material manufacturing, aerospace, and defense applications. Sensor operation in the aforementioned extreme environments require robust devices capable of sustaining the targeted high temperatures, while maintaining a stable sensor response. Current technologies face challenges regarding device or system size, complexity, operational temperature, or stability.

Surface acoustic wave (SAW) sensor technology using high temperature capable piezoelectric substrates and thin film technology has favorable properties such as robustness; miniature size; capability of mass production; reduced installation …

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 …

Surface Reaction And Diffusion Kinetics In Semiconducting Metal Oxide Film Gas Sensors, Aravind Reghu

Electronic Theses and Dissertations

Chemiresistive metal oxide gas sensors based on materials such as SnO₂, ZnO, and TiO₂, have been investigated extensively by many researchers for a wide range of applications. The band bending model, based on the surface chemistry of highly reactive ionosorbed species (O₂^- or O^-) and the semiconducting material properties of SnO₂, TiO₂ and ZnO, adequately predicts the dependence of the change in sensor conductivity (Δσ) as a function of target gas pressure and temperature. However, the band bending model is not applicable to gas sensors based on reducible oxides …

Antineutrino-Induced Charge Current Quasi-Elastic Neutral Hyperon Cross-Section On Argon In Argoneut, Samuel M. Borer

Honors College

This thesis outlines the first measurement of CCQE neutral hyperon production cross section in a liquid argon time projection chamber (LArTPC) through a topological study [1] and presents the ongoing progress of the addition of a calorimetric study. The analysis uses 1.20 £ 1020 protons-on-target, in the NuMI beam operating in the low energy antineutrino mode. The results of the topological study provide a total cross section measurement at the mean production energy of 3.42 GeV for CCQE neutral hyperons. The result of the topological study is consistent with the NUANCE cross section model and sets a 90% confidence level …

Probing The Nature Of Student Reasoning Using Modified Chaining Tasks, Ryan Moyer

Honors College

Research-based materials developed by the physics education research community have helped improve student conceptual understanding in introductory physics courses. A growing body of work, however, suggests that poor student performance on certain physics tasks, even after research-based instruction, may result from the nature of student reasoning itself than from conceptual difficulties. Drawing upon dual-process theories of reasoning, it has been argued that some of the poor performance from the presence of salient distracting features (SDFs) in physics problems, which may cue an incorrect first-available mental model and effectively preclude the student from drawing upon relevant knowledge.

In this study, we …