Physical Sciences and Mathematics Commons^™

Distribution And Characterization Of Rhyolites Of The Strawberry Volcanics -- Evolution Of A Major Rhyolite Field Associated With Columbia River Basalt Magmatism, Eastern Oregon, Usa, Chanel Leigh Dvorak

Dissertations and Theses

The Strawberry Rhyolites constitute a significant rhyolite field among the largest in Oregon. Aerial coverage of approximately 386 km² and an overall estimated volume of ~67 km³ using a median thickness for each unit. On the other hand, the total volume could be greater than 100 km³ if greater thicknesses apply. The Strawberry Rhyolites, a largely unknown mid-Miocene silicic volcanic rocks, crop out amongst voluminous flood basalt flows of the Columbia River Basalt Group (CRBG) in eastern Oregon. The eruptive activity of the Strawberry Rhyolites is currently constrained to span a period of about 2 million years, …

An Instructional Guide To Environmental Campaigns For K-12 Schools, Erin Mccarty

University Honors Theses

Evidence suggests environmental education can correlate with both short- and long-term behavioral changes, but existing research on the effectiveness of popular environmental education tactics show mixed results. Qualitative research was used in this study to assess student engagement and behavioral change within the context of environmental education campaigns. Ideally, students exposed to environmental campaigns become more informed on environmental issues and adjust their behavior to align with the campaign’s objectives. However, only a portion of environmental campaigns have these desired effects on their students. Based on a preliminary literature review, I anticipated the defining catalyst on post-campaign behavioral engagement would …

Characterization And Interpretation Of Feldspathic Chromite Assemblages (Fcas) In Four Ordinary Chondrites: An Electron Backscatter Diffraction (Ebsd) Study, Kimberly Louisa Maccini

Dissertations and Theses

Feldspathic Chromite Assemblages (FCAs) are chemically distinctive assemblages rich in Na, Al, and Cr that are found in a variety of chondrites. They consist of concentrations of chromite associated mainly with feldspathic material, either feldspar or the glassy material known as maskelynite. Professor Alan Rubin (2003) has proposed that some FCAs formed by shock melting, but the origin of different types of feldspathic chromite assemblages are unclear and have not been studied with more modern techniques such as Electron Backscatter Electron Diffraction (EBSD).

Here EBSD was used to study FCAs in four metamorphosed ordinary chondrites of different shock stages, including …

Ecological Exposure And Effects Of Microplastics In Crabs Along The Pacific Coast, Dorothy A. Horn

Dissertations and Theses

Microplastics have been documented across the global oceans as an ubiquitous pollutant. Found in the water column, sediment, shorelines, estuaries, freshwater streams and rivers along with terrestrial soils, flora and fauna. The continuous input of plastic waste into the marine environment doesn't seem to be slowing as the amount of plastic created each year increases globally.

This study investigated (1) the effects of microplastic ingestion in the indicator species, the Pacific mole crab (Emerita analoga), testing the predator avoidance behavior, reproductive output and parasitism effects when an adult female gravid crab had ingested microplastics (2) adult mortality, hatching …

Quantum Field Theories, Topological Materials, And Topological Quantum Computing, Muhammad Ilyas

Dissertations and Theses

A quantum computer can perform exponentially faster than its classical counterpart. It works on the principle of superposition. But due to the decoherence effect, the superposition of a quantum state gets destroyed by the interaction with the environment. It is a real challenge to completely isolate a quantum system to make it free of decoherence. This problem can be circumvented by the use of topological quantum phases of matter. These phases have quasiparticles excitations called anyons. The anyons are charge-flux composites and show exotic fractional statistics. When the order of exchange matters, then the anyons are called non-Abelian anyons. Majorana …

Error Propagation And Algorithmic Design Of Contour Integral Eigensolvers With Applications To Fiber Optics, Benjamin Quanah Parker

Dissertations and Theses

In this work, the finite element method and the FEAST eigensolver are used to explore applications in fiber optics. The present interest is in computing eigenfunctions u and propagation constants β satisfing [sic] the Helmholtz equation Δu + k²n²u = β²u. Here, k is the freespace wavenumber and n is a spatially varying coefficient function representing the refractive index of the underlying medium. Such a problem arises when attempting to compute confinement losses in optical fibers that guide laser light. In practice, this requires the computation of functions u referred to as …

Rapid Method For Consistency And Concentration Reporting Of Cannabidiol Using 1H-Nmr And Computer-Assisted Chemical Software, Michael A. Fernando

University Honors Theses

An integrated computational method was demonstrated with hemp-derived Cannabidiol for an assessment of its purity and concentration. The sample was structurally verified, high purity, and 2.98 mmol/L in dissolved DMSO. The method presented is a general approach to assessing purity and concentration for any small organic molecule in CMC-Assist.

Community College Geoscience Faculty Perspectives On Critical Thinking Instructional Tools, Mariela Salas Bao

Dissertations and Theses

Research has shown that modern courses and programs designed to foster critical thinking vary in both content and delivery, in turn leading to differences in their effectiveness. Few studies have investigated critical thinking among nontraditional students at community colleges taking STEM courses, especially within the geosciences. Furthermore, such research has focused primarily on the students with few if any studies involving faculty. This study examined the perceptions held by community college geoscience faculty regarding critical thinking and how such perceptions influenced their choice of instructional strategies. This study used a basic qualitative methodology and a maximum variation sampling to select …

Exploring The Potential Use Of Porous Silica Nanoparticles In Cest-Mri, Lydia Makotamo

Dissertations and Theses

Magnetic resonance imaging (MRI) is a widely used modality in diagnostics, treatment, and monitoring various conditions due to its ability to generate high-resolution images using non-ionizing radiation. The advent of contrast agents, which generally work by increasing the spin relaxation rate constants of water protons, has led to image enhancement. Despite the usefulness of this class of agents in diagnostic medicine, their inability to provide in-depth functional and anatomical information, coupled with their high detection limits, has led to new agents being explored.

Chemical exchange saturation transfer (CEST) presents an alternative route to generate signals via repetitive saturations transfers between …

Designing Environmentally Responsible And Highly Effective Bioorthogonally Functionalized Chiral Mri Contrast Agents, Karley Breann Maier

Dissertations and Theses

Magnetic resonance imaging (MRI) revolutionized diagnostic imaging and modernized the characterization of numerous diseases. The clinical success of MRI is in large part due to the employment of gadolinium-based contrast agents (GBCAs). Due to sensitivity limitations, GBCAs are indicated at markedly high dosages (~1 g Gd³⁺ per exam). The routine use of such large quantities of gadolinium poses significant health and environmental risks. There are growing concerns over the effects of dechelation of the metal in vivo and the possible effect of resulting gadolinium deposition. Concurrently, there is a rising awareness of gadolinium anomalies borne by GBCAs which undergo …

Situate: An Agent-Based System For Situation Recognition, Max Henry Quinn

Dissertations and Theses

Computer vision and machine learning systems have improved significantly in recent years, largely based on the development of deep learning systems, leading to impressive performance on object detection tasks. Understanding the content of images is considerably more difficult. Even simple situations, such as "a handshake", "walking the dog", "a game of ping-pong", or "people waiting for a bus", present significant challenges. Each consists of common objects, but are not reliably detectable as a single entity nor through the simple co-occurrence of their parts.

In this dissertation, toward the goal of developing machine learning systems that demonstrate properties associated with understanding, …

From Mdp To Alphazero, David Robert Sewell

Dissertations and Theses

In this paper I will explain the AlphaGo family of algorithms starting from first principles and requiring little previous knowledge from the reader. The focus will be upon one of the more recent versions AlphaZero but I hope to explain the core principles that allowed these algorithms to be so successful. I will generally refer to AlphaZero as theses [sic] core set of principles and will make it clear when I am referring to a specific algorithm of the AlphaGo family. AlphaZero in short combines Monte Carlo Tree Search (MCTS) with Deep learning and self-play. We will see how these …

Project To Establish Growth & Mortality Rates Of Three Carex Species In Two Planting Types At Thomas Dairy Site, Tigard, Oregon, Ben Huffine

Environmental Science and Management Professional Master's Project Reports

Clean Water Services (CWS) currently increases the diversity of their wetland restoration projects using a plug planting method utilizing juvenile herbaceous plants. They have planted most of their projects using this method and plan to continue until a better one is discovered. According to the literature reviewed in this paper, juvenile plants are smaller and weaker than more mature plants and therefore have higher mortality rates. This paper is the culmination of work completed of phase 1 of this two-phase project. The objective of this project (both phases) was to design and establish a study that would test, in the …

Closed Canopies Crowd Out Bats: Planning Artificial Gap Creation, Alana Simmons

Environmental Science and Management Professional Master's Project Reports

Managed even-aged forest stands often lack small to medium-sized canopy gaps that help to increase habitat diversity and, in turn, wildlife diversity. A large body of literature suggests that this habitat diversity is especially important for bat communities and that bat activity and diversity can be depressed in closed canopy, even-aged stands. Open- and edge-adapted bats have evolved specific wing morphologies and echolocation call structures that make them reliant upon forest gaps as energy efficient foraging grounds in otherwise structurally cluttered forests. Artificial gap creation projects that increase habitat diversity have been implemented to benefit ungulates, and a similar approach …

Expanding Temperature Sensing For The Orion Bms 2, Samuel J. Parker

University Honors Theses

Formula SAE (FSAE) is an annual collegiate design competition that takes place across the globe. Portland State University’s team, Viking Motorsports, was committed to designing an Electric Vehicle (EV) for the 2021 FSAE competition. The team designed a completely custom lithium-ion cell battery that is managed by an Orion BMS 2 battery management system. The FSAE rulebook requires a robust temperature monitoring system for any EV power supply. The Orion BMS 2 can only directly collect data from eight temperature sensors, which is not enough to meet FSAE regulation. However, the BMS can be configured to monitor many more sensors …

Mid-Miocene Icelandites Of Eastern Oregon: Petrogenesis And Magmatic Lineage To Main-Phase Crbg With Constraints On Storage Sites, Melissa Aileen Carley

Dissertations and Theses

The La-Grande Owyhee eruptive axis is a mid-Miocene to Pliocene ~300 km long volcanic belt located at the eastern margin of the Columbia River Basalt Group (CRBG) in Oregon. Within this volcanic belt there are numerous vents that have produced a large volume of petrologically diverse rocks ranging from the tholeiitic flood basalts of the CRBG to rhyolitic tuffs of caldera complexes such as the Lake Owyhee Volcanic field. Icelandites, which are iron rich andesites, are known to occur in association with silica saturated to oversaturated tholeiitic basalts as a minor part of continental flood basalt volcanism. This study investigates …

Major Controls On Diagenesis In The Martin Bridge Formation: Wallowa Mountains, Oregon, Jane Lyra Eisenberg

Dissertations and Theses

Diagenetic alteration in carbonates has long frustrated scientists who wish to use their chemistry and/or texture to understand conditions at the time of deposition. Though indicators of diagenesis are well documented, their interpretation is not always straightforward. Despite the large volume of research on the subject, the positive identification and interpretation of diagenesis is a source of ongoing debate in the scientific community.

The goal of this study is to better understand the timing of, and controls on, diagenetic alteration in the Martin Bridge Formation (MBF), a Triassic-aged limestone that was altered following deposition. Thirty-nine samples of MBF with differing …

The Return To Anisotropy Across A Jet In Crossflow, Gregory P. Sakradse

Dissertations and Theses

With data from experiments on a jet of air emitting from an orifice flush with the floor of a wind tunnel providing a transverse flow, analysis is conducted to extract information about the state of anisotropy in the Reynolds stress tensor. Inflow velocities are modulated across two distinct turbulence intensity regimes while holding jet exit conditions constant, providing an opportunity to isolate effects of both jet to crossflow velocity ratio, r and the effects of the turbulence carried by the crossflow. Anisotropy in the Reynolds stress tensor is examined through anisotropy invariant maps and evolution of the function F, …

Selenium Probes For The Detection Of Thioredoxin Reductase Activity, Tendai Joseph Mafireyi

Dissertations and Theses

The identification and quantification of proteins and enzymatic activity in living tissues frequently requires the use of invasive procedures such as biopsy. These techniques can inhibit measurements of protein levels in real-time, and the disruption of tissue can lead to the loss of important information concerning the spatial distribution and differential activities in various cell types. The use of small organic fluorescent probes that rely on activation or accumulation within a tissue embody robust methods of detection that address these issues. This dissertation describes the design, synthesis and evaluation of fluorescent probes that can detect the enzyme thioredoxin reductase (TrxR). …

Forest Fire Effects On The Temporal Variability Of Landscape Snow Albedo Relative To Burn Severity, Max Gersh

Dissertations and Theses

Snow-water storage is decreasing, while forest fires are increasing in duration, size, frequency, and intensity, due to climate change. Most forest fires occur in the seasonal snow zone, altering snow mass and energy balance for many years following fire. Following forest fires, Surface snow albedo (SSA) decreases, as light absorbing particles (LAP), particularly black carbon (BC) produced in forest fires get deposited throughout the snowpack, altering snowpack energy balance driving earlier snowmelt in burned forests. While SSA decreases, landscape snow albedo (LSA) increases following fire, as more of the snow-covered surface becomes visible beneath the burned forest canopy, brightening the …

Efficient Neuromorphic Algorithms For Gamma-Ray Spectrum Denoising And Radionuclide Identification, Merlin Phillip Carson

Dissertations and Theses

Radionuclide detection and identification are important tasks for deterring a potentially catastrophic nuclear event. Due to high levels of background radiation from both terrestrial and extraterrestrial sources, some form of noise reduction pre-processing is required for a gamma-ray spectrum prior to being analyzed by an identification algorithm so as to determine the identity of anomalous sources. This research focuses on the use of neuromorphic algorithms for the purpose of developing low power, accurate radionuclide identification devices that can filter out non-anomalous background radiation and other artifacts created by gamma-ray detector measurement equipment, along with identifying clandestine, radioactive material.

A sparse …

Investigation Of Environmental-Friendly, Membraneless Hydrogen Peroxide Fuel Cells, Bao Nguyen

Dissertations and Theses

Human-induced climate change is one of the biggest threats to humanity in the 21^st century. This is caused by the increase in greenhouse gas concentrations in the Earth's atmosphere. The burning of fossil fuels is the primary cause of climate change. This problem can be addressed by replacing fossil fuels with fuel sources that have clean by-products and are cost-effective. For the last few decades, hydrogen (H₂) has been extensively studied as an alternative to carbon-based fossil fuels. Currently, H₂ still has many shortcomings for commercial applications. The photocatalytic production of H₂ still suffers from …

Rhyolite Stratigraphy Along Succor Creek: Insights Into The Eruptive History Of The Three Fingers And Mahogany Mountain Volcanic Field, Cassandra Caryl Black

Dissertations and Theses

The Mahogany Mountain and Three Fingers calderas with their associated tuffs, the tuff of Leslie Gulch and tuff of Spring Creek, respectively, were the centerpiece of a larger rhyolite center that developed in response to Columbia River Basalt volcanism as numerous other mid Miocene rhyolite centers in a corridor from Baker City in the north to northern Nevada. Previous studies suggest a two caldera model, while others advocated for a single large caldera producing solely the tuff of Leslie Gulch. This study refines the eruptive stratigraphy along the northeastern margin of this rhyolite field with important implications for the entire …

Mechanistic Investigation Of Neuropeptide S-Nitrosylation By Nitric Oxide Moieties: A Kinetic And Thermodynamic Approach, Vusumuzi Leroy Sibanda

Dissertations and Theses

This dissertation focuses on providing quantitative insights regarding kinetic, thermodynamic and mechanistic parameters of neuropeptide S-nitrosylation by nitrous acid (HNO₂), peroxynitrite (ONOO^-) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) to produce S-nitrosothiols (SNOs). Peptide thiol stability and the formation of SNOs from neuropeptides; arginine vasopressin (AVP), somatostatin-14 (SST-14) and urotensin II (U-II) was studied. Investigations into the effects of temperature, copper chelators and pH on peptide thiol autoxidation show that AVP, SST-14 and U-II thiols have half-lives of 30, 44 and 28.2 mins respectively at physiologically relevant temperature and pH in the absence of metal chelators. Target peptide thiols were …

Automated Statistical Structural Testing Techniques And Applications, Yang Shi

Dissertations and Theses

Statistical structural testing(SST) is an effective testing technique that produces random test inputs from probability distributions. SST shows superiority in fault-revealing power over random testing and deterministic approaches since it heritages the merits from both of them. SST ensures testing thoroughness by setting up a probability lower-bound criterion for each structural cover element and test inputs that exercise a structural cover element sampled from the probability distribution, ensuring testing randomness. Despite the advantages, SST is not a widely used approach in practice. There are two major limitations. First, to construct probability distributions, a tester must understand the underlying software's structure, …

Quantum Grover's Oracles With Symmetry Boolean Functions, Peng Gao

Dissertations and Theses

Quantum computing has become an important research field of computer science and engineering. Among many quantum algorithms, Grover's algorithm is one of the most famous ones. Designing an effective quantum oracle poses a challenging conundrum in circuit and system-level design for practical application realization of Grover's algorithm.

In this dissertation, we present a new method to build quantum oracles for Grover's algorithm to solve graph theory problems. We explore generalized Boolean symmetric functions with lattice diagrams to develop a low quantum cost and area efficient quantum oracle. We study two graph theory problems: cycle detection of undirected graphs and generalized …

Proximal Policy Optimization For Radiation Source Search, Philippe Erol Proctor

Dissertations and Theses

Rapid localization and search for lost nuclear sources in a given area of interest is an important task for the safety of society and the reduction of human harm. Detection, localization and identification are based upon the measured gamma radiation spectrum from a radiation detector. The nonlinear relationship of electromagnetic wave propagation paired with the probabilistic nature of gamma ray emission and background radiation from the environment leads to ambiguity in the estimation of a source's location. In the case of a single mobile detector, there are numerous challenges to overcome such as weak source activity, multiple sources, or the …

Information Security Maturity Model For Healthcare Organizations In The United States, Bridget Joan Barnes Page

Dissertations and Theses

This research provides a maturity model for information security for healthcare organizations in the United States. Healthcare organizations are faced with increasing threats to the security of their information systems. The maturity model identifies specific performance metrics, with relative importance measures, that can be used to enhance information security at healthcare organizations allowing them to focus scarce resources on mitigating the most important information security threat vectors. This generalizable, hierarchical decision model uses both qualitative and quantitative metrics based on objective goals. This model may be used as a baseline by which to measure individual organizational performance, to measure performance …

Exploring Linkages Between Landscape Patterns And Freshwater And Estuarine Bivalves In The Coast Range Of Oregon, Kaegan Michael Scully-Engelmeyer

Dissertations and Theses

Spatial configurations of landscape variables (biotic, abiotic, and socio-ecological) affect and are affected by ecological processes and species in watersheds. This dissertation explores relationships among landscape patterns, ecosystem processes and bivalve species dynamics in coastal watersheds in Oregon, USA. I approached this broad topic through two primary avenues of research: investigating cross-ecosystem threats from pesticide use in forestland management to downstream aquatic environments, and the landscape ecology of an at-risk freshwater mussel species.

Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, …

Regional Characteristics And Variability Of Extreme Precipitation And Atmospheric Rivers In Past, Present, And Future Climates Over The Contiguous United States, Emily Anne Slinskey

Dissertations and Theses

This dissertation examines the regional and seasonal variability of extreme precipitation and atmospheric rivers (ARs) across the contiguous United States (CONUS) in past, present, and future climates. An extreme precipitation categorization scheme, designed to monitor and track the multi-scale variability of extreme precipitation, is applied to a range of precipitation measurement products as an assessment of observational uncertainty. To investigate the importance of ARs across the CONUS, an objective AR identification algorithm is applied to global reanalysis to identify and characterize AR characteristics regionally over the observational record. Projected change in AR day frequency, geometry, intensity, and associated precipitation is …