Physical Sciences and Mathematics Commons^™

Inventory Of Rock Glaciers In The American West And Their Topography And Climate, Allison Reese Trcka

Dissertations and Theses

Rock glaciers are flowing geomorphic landforms composed of an ice/debris mixture. A uniform rock glacier classification scheme was created for the western continental US, based on internationally recognized criteria, to merge the various regional published inventories. A total of 2249 rock glaciers (1564 active, 685 inactive) and 7852 features of interest were identified in 10 states (WA, OR, CA, ID, NV, UT, ID, MT, WY, CO, NM). Sulfur Creek rock glacier in Wyoming is the largest active rock glacier (2.39 km²). The mean area and elevation for active and inactive rock glaciers are 0.18 km², 3384 …

Pharmaceuticals And Personal Care Products In Pacific Northwest Coastal Ecosystems: Spatial Variation, Organism Effects, And Consumer Perspectives, Amy Lynne Ehrhart

Dissertations and Theses

Anthropogenic pollution poses a threat to marine organisms and ecosystems worldwide. Common chemical pollutants that enter the marine environment include legacy contaminants, which are well known and heavily regulated or banned pollutants, and emerging contaminants, which are more recently recognized as pollutants and often lack regulatory limits for their use and discharge. Wastewater treatment plant (WWTP) effluent is a major source of various contaminants of concern, particularly pharmaceutical and personal care products (PPCPs) that are not fully removed during treatment. PPCPs exist at low concentrations in the environment and may have unknown and subtle effects on marine life. Data gaps …

Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt

Dissertations and Theses

Strong earthquake shaking is a natural hazard threat in the Pacific Northwest. Soil failure due to strong earthquake shaking -- known as cyclic soil failure or liquefaction -- is expected to cause large ground deformations and damage to roads, bridges, and other civil infrastructure. Cyclic soil strength (CRR) is often characterized with in-situ geotechnical tests including the cone penetration test (CPT). Relationships between CRR and in-situ test data are not well established for soils in the Pacific Northwest. Portland State University, in partnership with New Albion Geotechnical has compiled a database of cyclic lab tests for Pacific Northwest soils to …

Wildfire Risk Assessment For A Municipal Watershed In Western Oregon, Usa: Methods For Projecting The Impact Of Mid-21st Century Climate Change On Wildfire Hazard, Andy Mcevoy

Dissertations and Theses

In the western United States, climate change is projected to lead to significant changes in regional wildfire regimes. Historically, forests west of the Cascade crest in Oregon and Washington, USA (westside) have been characterized by low-frequency wildfire events, but climate change projections indicate that wildfire could become a more common disturbance, altering ecological processes and impairing ecosystem services like surface water quality and quantity. Wildfire risk assessments based on simulation models have been used in high frequency fire regimes to evaluate contemporary and future risk, but present unique challenges in westside forests because characteristic low annual burn probabilities result in …

Investigating Dose-Dependent, Multi-Generational, And Strain-Specific Effects Of 17Α-Ethynylestradiol Exposure In Zebrafish (Danio Rerio), Decatur Mitochondria Foster

Dissertations and Theses

Endocrine disrupting chemicals (EDCs) pose a threat to biodiversity at the individual, population, and ecosystem level, as they can interfere with processes that are responsible for regulating metabolism, development, behavior, and reproduction in living organisms. 17α-ethynylestradiol (EE2) is a synthetic estrogen and EDC utilized in pharmaceutical and livestock industries, and contaminates waterways worldwide. This research explores the effects of dose-dependent and multi-generational exposure of EE2 in three strains of zebrafish. High dose (10-25 ng/L EE2) exposure led to complete reproductive failure, as well as significantly decreased survival and growth. A period in clean water (depuration) after exposure allowed for some …

Aryne-Guided C-H Functionalization Of Benzenoid Rings Using Diaryliodonium Salts, Aleksandra Nilova

Dissertations and Theses

The benzenoid core is a frequent and irreplaceable component of biologically active molecules. Structure function relationship of these compounds has been broadly analyzed and presented in numerous literature reports. Herein, we augmented existing knowledge by a broad analysis of the benzenoid substitution patterns in small molecule active pharmaceutical ingredients approved by the FDA. Our findings reveal a strong correlation that the most represented substitution patterns are those achieved via S_EAr. Despite the rapid development of methods to functionalize benzenoid rings, the lack of synthetic methodologies to access sterically and electronically unfavorable positions is highlighted. We sought to establish …

Microplastics In Pacific Northwest Bivalves: Ecological Prevalence, Harvester-Consumer Exposure, And Aquarium Exhibit Outcomes, Britta Rahel Baechler

Dissertations and Theses

Up to 23 million metric tons of mismanaged plastics enter the global ocean annually. Microplastics (MPs;<5mm) degrading. MPs leak into the environment and now pervade every corner of the earth, with implications for animal, plant, ecosystem and human health. It is important to understand localized environmental MP prevalence, distribution and organismal uptake in order to determine the extent of MP pollution, and ultimately unlock solution sets to reduce transmission of MPs into the natural world. In Chapter 2, I quantified MP types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 coastal sites in Oregon. Both of these species are integral to culture, economy, gastronomy and food security along the United States West Coast. In Chapter 3, I quantified MPs in Pacific razor clams collected from 8 Olympic Coast, Washington sites, administered questionnaires to recreational razor clammers and subsequently estimated annual MP exposure of those Olympic Coast razor clam harvester-consumers surveyed. In Chapter 4, I designed and installed an educational ocean plastic …

A Posteriori Error Estimates For Maxwell's Equations Using Auxiliary Subspace Techniques, Ahmed El Sakori

Dissertations and Theses

The aim of our work is to construct provably efficient and reliable error estimates of discretization error for Nédélec (edge) element discretizations of Maxwell's equations on tetrahedral meshes. Our general approach for estimating the discretization error is to compute an approximate error function by solving an associated problem in an auxiliary space that is chosen so that:

-Efficiency and reliability results for the computed error estimates can be established under reasonable and verifiable assumptions.

-The linear system used to compute the approximate error function has condition number bounded independently of the discretization parameter.

In many applications, it is some functional …

Investigation Of Prussian Blue Analogues As Cathode Materials For Next Generation Batteries, Neal Walters Kuperman

Dissertations and Theses

Since the beginning of the industrial revolution, the average global temperature has risen about 1 °C due increases in anthropogenic greenhouse gases emitted into the atmosphere. Of all human produced greenhouse gases, carbon dioxide is the most prevalent, with the production of electricity from fossil fuels being the major contributor.

Solar and wind power are promising net zero emission energy sources but only accounted for ~5% of global electricity generation in 2016. The most significant hurdle hindering their widespread adoption is the intermittent nature of the electricity generation. To overcome this limitation, significant resources need to be put into the …

Exploring The Potential Of Sparse Coding For Machine Learning, Sheng Yang Lundquist

Dissertations and Theses

While deep learning has proven to be successful for various tasks in the field of computer vision, there are several limitations of deep-learning models when compared to human performance. Specifically, human vision is largely robust to noise and distortions, whereas deep learning performance tends to be brittle to modifications of test images, including being susceptible to adversarial examples. Additionally, deep-learning methods typically require very large collections of training examples for good performance on a task, whereas humans can learn to perform the same task with a much smaller number of training examples.

In this dissertation, I investigate whether the use …

Determinants Of Green Purchase Intentions Of Saudi Consumers, Amani Mohammed Kaadoor

Dissertations and Theses

Much of the research on how and why consumers engage in pro-environmental consumption has occurred in the wealthy countries of the West, where green markets are increasingly well established. Research in other economic and cultural context is sparse and points to large regional differences that cause some researchers to call key theoretical foundations, such as the Theory of Planned Behavior, into question. In response, this study investigates the factors that predict green purchase intention for food and personal care products in Saudi Arabia, a wealthy country with a rapidly growing population, severe environmental challenges, and a nascent green consumer market …

Do Fungal Symbionts Of Salt Marsh Plants Affect Interspecies Competition?, Vanessa Robertson-Rojas

Dissertations and Theses

The effects of arbuscular mycorrhizal fungi (AMF) as salt marsh plant symbionts may have significant effects on landscape scale distribution patterns and plant-related ecosystem functions that are important to estuarine habitats. This work investigates the effects AMF have on Phalaris arundinacea, Deschampsia cespitosa, and Juncus balticus when grown in a common garden experiment. Plants were grown with and without AMF inoculation in both polyculture and monoculture communities and examined for a variety of response variables that represent different competition strategies. Factorial ANOVA analysis revealed a significant three-way interaction among fungal treatment type, community type, and species for …

Indoor Air Quality Impacts Of A Woodstove Exchange Program In Washington County, Oregon, Matthew Forrest Survilo

Dissertations and Theses

More than six million people in the United States use wood stoves as their primary heat source. Wood stoves emit air pollutants that may impact health, e.g., wood combustion products are associated with premature death and aggravation of pulmonary and cardiovascular conditions. There are few studies investigating the efficacy of wood stove exchange programs (WSEPs) as a method to improve indoor air quality (IAQ). In partnership with Washington County Department of Health and Human Services we conducted an air quality study to measure the impact of a WSEP on indoor and neighborhood levels of wood combustion products. Twenty households engaged …

Waste Management In The Global South: An Inquiry On The Patterns Of Plastic And Waste Material Flows In Colombo, Sri Lanka, Katie Ann Conlon

Dissertations and Theses

Global plastic production continues to increase at an exponential pace, and global waste projections show waste generation rising by 70% by 2050. Plastic waste connects to all social processes, especially within the context of urbanization and development; urban planning and land management; GHG emissions; labor; social equity; public health; rural-to-urban migration; increasing population; increasing consumption; climate change; etc. The focus of this dissertation is an analysis of waste management practices in Sri Lanka using a grounded theory based methodology, with a goal to better understand the social and ecological impacts of plastic waste in Sri Lanka. This research fills a …

Investigation Of Magnetism In Transition Metal Chalcogenide Thin Films, Michael Adventure Hopkins

Dissertations and Theses

Layered two dimensional films have been a topic of interest in the materials science community driven by the intriguing properties demonstrated in graphene. Tunable layer dependent electrical and magnetic properties have been shown in these materials and the ability to grow in the hexagonal phase provides opportunities to grow isostructural stacked heterostructures. In this investigation, cobalt selenide (CoSe) and nickel selenide (NiSe) were grown in the hexagonal phase, which consist of central metal atoms that are natively ferromagnetic in bulk, hence providing the potential for interesting magnetic phases in thin film arrangements as well. These structures may play a role …

A Seasonal Study Of Ecoroof Metal And Nutrient Dynamics And Associated Drivers In An Ecoroof On A Commercial Building In North Portland Oregon, Alex Vijay Bans

Dissertations and Theses

Green stormwater infrastructure (GSI), specifically ecoroofs, is increasingly seen as an effective stormwater management tool in urban planning strategies. However, the literature suggests that ecoroofs can be sources of certain metals and nutrients. The goal of our study was to address two research questions: 1) How does ecoroof runoff compare to conventional roof runoff chemically: do ecoroofs retain certain chemicals and leach others? and 2) what are the roof characteristics and environmental variables that affect runoff quality? For 10 months, runoff events from an ecoroof were compared to those of a conventional roof; water samples were collected with autosamplers, and …

Designing A More Effective Mri Contrast Agent: Investigation Into Various Functionalization Strategies For Targeted Imaging, Lauren Nicole Rust

Dissertations and Theses

Magnetic resonance imaging (MRI) is a medical imaging technique that provides high-resolution images used for diagnostic medicine while maintaining a superior safety profile compared to other radiative techniques. The administration of gadolinium-based contrast agents (GBCAs) improves the diagnostic power of MRI and have been used clinically for over three decades. Although GBCAs are effective at improving the contrast in the image, their detection limits are high and require a large dose to generate an observable effect. This high dose is the consequence of the current available designs of clinical GBCAs; their structures are not tuned to generate optimal efficacy. Efficacy …

Distribution, Geochronology, And Petrogenesis Of The Picture Gorge Basalt With Special Focus On Petrological Relationships To The Main Columbia River Basalt Group, Emily Bogdan Cahoon

Dissertations and Theses

The Columbia River Basalt Group (CRBG) is the youngest and volumetrically smallest continental flood basalt exposed across the Pacific Northwest, USA. Similar to other large igneous provinces, the majority of material erupted during the initial 1 million years of activity, these lavas are subdivided into four main-phase units. The Picture Gorge Basalt (PGB) is the only main-phase unit of the CRBG whose age is not precisely known and understanding of PGB petrogenesis is largely based on a limited number of samples when compared with other main-phase units. It is suggested that a time gap of over 0.5 myr existed between …

Novel View Synthesis - A Neural Network Approach, Hoang Le

Dissertations and Theses

Novel view synthesis is an important research problem in computer vision and computational photography. It enables a wide range of applications including re-cinematography, video enhancement, virtual reality, etc. These algorithms leverage a pre-acquired set of images taken from a set of viewpoints to synthesize another image at a novel viewpoint as if it was captured by a real camera. To synthesize a high-quality novel view, these algorithms often assume a static scene, or the images were captured synchronously. However, the scenes in practice are often dynamic, and taking a dense set of images of these scenes at the same moment …

Synthesis And Assessment Of Radiotherapy-Enhancing Nanoparticles, Hayden Winter

Dissertations and Theses

Radiation Therapy (RT) is a common treatment for cancerous lesions that acts by ionizing matter in the affected tissue, causing cell death. The disadvantage of RT is that it is most often delivered via an external beam of radiation which must pass through healthy tissues to reach the target site, ionizing matter within healthy tissues as well. To address this drawback, techniques are being developed for increasing RT-induced cell death in a target tissue while minimizing cell death in surrounding tissues. This effect is known as radiation dose enhancement or RT enhancement.

The approach to RT enhancement studied in this …

A Computer Science Academic Vocabulary List, David Roesler

Dissertations and Theses

This thesis documents the development of the Computer Science Academic Vocabulary List (CSAVL), a pedagogical tool intended for use by English-for-specific-purpose educators and material developers. A 3.5-million-word corpus of academic computer science textbooks and journal articles was developed in order to produce the CSAVL. This study draws on the improved methodologies used in the creation of recent lemma-based word lists such as the Academic Vocabulary List (AVL) and the Medical Academic Vocabulary List (MAVL), which take into account the discipline-specific meanings of academic vocabulary. The CSAVL provides specific information for each entry, including part of speech and CS-specific meanings in …

Guided Reinvention As A Context For Investigating Students' Thinking About Mathematical Language And For Supporting Students In Gaining Fluency, Kristen Vroom

Dissertations and Theses

Fluency with mathematical language is important for students' engagement in many disciplinary practices such as defining, conjecturing, and proving; yet, there is growing evidence that mathematical language is challenging for undergraduate students. This dissertation study draws on two design experiments with pairs of students who were supported to encode their mathematical meanings with more formal language. I aimed to investigate the teaching and learning of mathematical language, and particularly the language in statements with multiple quantifiers, by engaging students in this type of activity. In the first paper, I investigated the complex ways in which the students in my study …

Mechanics Of Canopy Turbulence, Hawwa Falih Kadum

Dissertations and Theses

Large canopies interact with the atmospheric boundary layer (ABL) and alter transport of matter, energy, and momentum in accordance to their morphology. Canopy structure influence on turbulent processes can be utilized to achieve favorable interactions. Wind farm and forest canopies spatial arrangement is investigated in this work. Momentum fluxes investigated in a horizontal axis wind turbine (HAWT) array showed the existence of gusts of wind transported both from ABL above the canopy and the unperturbed flow below the canopy through sweep and ejection events. A new wind farm arrangement in which clusters of vertical axis wind turbines (VAWT) are collocated …

Testing The Correlation Of Trace Element Characteristics With The Petrology And Temperature Of Eruption Of Mid-Miocene Rhyolites In Eastern Oregon, Brianna Christine Young

Dissertations and Theses

The Lake Owyhee Volcanic Field (LOVF) in eastern Oregon experienced several major eruptive events during the mid-Miocene (16.8 to 15.5 Ma), resulting in the emplacement of 3,900 km³ of rhyolitic lava flows and ash-flow tuffs. Eighteen samples from eleven different silicic centers in the LOVF were selected for this study. While all samples of this study are classified as rhyolite, their compositions vary greatly in terms of trace and major elements. Using trace elements, these rhyolite samples are classified as "A-type", described as resulting from "hot and dry" magmas and associated with hot-spot activity, or as "I-type" or "calc-alkaline", …

Understanding Institutional, Social, And Ecological Systems Influencing Climate Change Adaptation And Water Governance In Wine Regions: A Comparative Case Study Of Oregon's Willamette Valley, Usa And Tasmania, Australia, Erin Upton

Dissertations and Theses

My research examines how water management decisions create opportunities or barriers to climate change adaptation in wine regions. Water is a critical resource for economic and environmental sustainability in wine grape growing regions. Climate uncertainty presents considerable risk and vulnerability to freshwater resources in wine producing regions where needs for access to water will increase with more frequent climate extremes. Climate adaptation in the wine industry is a complex problem that requires multi-disciplinary approaches. This research aims to strengthen the interface between water governance and technological and viticulture adaptation approaches. Water resources are shared across regions by stakeholders with varied …

The Rocky Ledge Fault, Shasta County, Ne California: Development And Morphology Of A Quaternary Oblique Normal Fault In Basalt, Gregory David Linscott Martin

Dissertations and Theses

Distinct morphology, variable vertical separation, and unique structural geometries are observed along the Rocky Ledge fault (RLF), an east-dipping, oblique normal fault in the tectonically complex Hat Creek Graben, Shasta County, NE California. Situated in the southern Cascade arc, the RLF is located at the boundary of the Klamath Mountains, Basin and Range, and Walker Lane Seismic Belt. The primary goal of this project is to better understand Quaternary deformation along the RLF. I developed detailed maps of geologic units and structures along the ~15 km length of the RLF. Map data informs assessment of fault geometry, scarp morphology, and …

Spatial Statistical Approaches To Water Quality Modelling, Janardan Mainali

Dissertations and Theses

This dissertation aims to advance the existing knowledge related to spatial modeling of water quality by exploring and introducing innovative approaches to different spatial conceptualizations for water quality modeling and incorporating upstream-downstream relations in geographically weighted regression. By carrying out a systematic literature review of four different classes of spatial models in Chapter One, this dissertation identifies the following major research gaps: lack of incorporation of multiscale processes, not enough emphasis on spatial weights matrices, and unavailability of upstream-downstream relationships in geographically weighted regressions. Chapters Two and Three were designed to address these gaps in the literature. In Chapter Two, …

Long Term Changes To The Lower Columbia River Estuary (Lcre) Hydrodynamics And Salinity Patterns, Aqeel Al-Bahadily

Dissertations and Theses

Changing the morphological and hydrological conditions of an estuary can affect the estuarine hydrodynamics. The hydrograph of the Lower Columbia River Estuary (LCRE) and its bathymetry have been altered significantly over the past 150 years, such that the spring-freshet has decreased by 40-50% while winter flow has increased by 50%. In addition, the inlet width has been narrowed from 9.7 to 3.2km by the construction of jetties, and the controlling depth of the navigation channel has been deepened from 6 to 13m by continuous dredging. Also, ~70% of the shallow water habitat has been lost due to diking and wetland …

Convex And Nonconvex Optimization Techniques For Multifacility Location And Clustering, Tuyen Dang Thanh Tran

Dissertations and Theses

This thesis contains contributions in two main areas: calculus rules for generalized differentiation and optimization methods for solving nonsmooth nonconvex problems with applications to multifacility location and clustering. A variational geometric approach is used for developing calculus rules for subgradients and Fenchel conjugates of convex functions that are not necessarily differentiable in locally convex topological and Banach spaces. These calculus rules are useful for further applications to nonsmooth optimization from both theoretical and numerical aspects. Next, we consider optimization methods for solving nonsmooth optimization problems in which the objective functions are not necessarily convex. We particularly focus on the class …

Collaboration And Evaluation In Urban Sustainability And Resilience Transformations: The Keys To A Just Transition?, Liliana Elizabeth Caughman

Dissertations and Theses

Climate has changed and will continue changing; city populations are swelling as urbanization continues to accelerate; extreme environmental events like heat waves and floods are becoming more severe and more common; and the climate justice movement is rapidly gaining momentum. It in this context that municipal governments find themselves urgently seeking solutions to transition cities from extractive, vulnerable, and unjust to sustainable, resilient, and equitable. The task is complex and will require systemic transformations across interconnected social, environmental, and economic infrastructures. Emerging theories regarding how to govern such massive changes suggest Transition Management strategies and the values of a just …