Digital Commons Network^™

Chondrites From Northwestern Nevada: The Jungo Dense Collection Area, Nico Morrelli

University Honors Theses

Dense collection areas are regions where meteorites are more frequently found, and can help researchers study the meteorite flux to Earth. The Jungo dry lake bed is a dense collection area (DCA) in Humboldt County, Nevada and is currently the recovery location of eleven officially classified meteorites. Five of these samples were classified as part of this work. All five are ordinary chondrites, two of which are likely paired with previously classified Jungo samples. Jungo 021 is likely paired with Jungo 005, and Jungo 017 is likely part of the previously established pairing group of Jungo 002, 003, and 004. …

Effects Of Fine Sediment On The Productivity Of Stream Ecosystems In The Pacific Northwest, Veena I. Davis

University Honors Theses

Salmon are important to the culture, ecosystem and economy of the Pacific Northwest. However, populations have declined significantly since European colonization. Salmon require specific conditions for each life stage and are highly sensitive to environmental stressors. Excess fine sediment is a leading form of pollution as it degrades salmon spawning habitat and the benthos upon which their main food source, stream insects, live. To evaluate the effect of sediment pollution on food availability for salmon smolt, we conducted an experiment  estimating the amount of stream insect biomass and calories lost due to sediment pollution. We counted insects on substrate samples …

Mycelial Modeling: Teaching Biology Students Statistical Modeling With Mushrooms, Colette Wolf

University Honors Theses

This paper summarizes and describes the development of a set of learning materials that were created to educate students and professionals from other fields in statistical modeling techniques. These materials are primarily aimed at biology students, but are still intended to be useful for anyone who is interested in incorporating decision trees and random forest models into their personal research in the future. By directing the reader towards the JMP software, these materials navigate around the statistical knowledge base and coding implementation practices that otherwise would serve as a barrier to learning statistical modeling techniques, and instead focus on the …

A Novel, Embedding-Based Approach To Longitudinal Survey Data Imputation, Julia Rezvani

University Honors Theses

Longitudinal surveys are ubiquitous in the social sciences as a means of tracking changes in behavior and opinions with time and identifying potential causal mechanisms. These surveys are frequently plagued by missing data and semantic drift, both of which limit their effectiveness and scientific utility. Imputation algorithms allow researchers to fill gaps in collected survey datasets, imperfectly reconstructing lost data. Although deep learning algorithms have been used in imputation to great success, approaches which simultaneously leverage the semantic and temporal structure of longitudinal surveys have not yet been developed. We propose a novel imputation architecture which is capable of leveraging …

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …

Projected Climate Change Impacts On Soil Greenhouse Gas Emissions From A Restored Freshwater Marsh, Annika Hendrickson

University Honors Theses

Wetlands provide valuable ecosystem services, one of which is a wetlands ability to sequester carbon. Climate change and human land use threaten a wetlands ability to do so. Globally, 21% of wetlands have been lost since the 1700s. As a result, restoration of wetlands has been increasing. However, wetlands in the process of restoration emit more methane than degraded ones, and as the climate continues to change, these fluxes could respond. Projected sea level rise is expected to cause salt water to infiltrate coastal freshwater systems, increasing the salinity. Past research has found that increased salinity has led to suppressed …

Uniform Stability Of Katyusha In Strongly-Convex Settings, Don Li

University Honors Theses

Acceleration of convergence and reduction of variance constitute a trade-off in the design of stochastic optimization machine learning algorithms. Katyusha was introduced to address this trade-off, synthesizing Nesterov Accelerated Gradient (NAG) and Stochastic Variance-Reduced Gradient (SVRG) into a single first-order optimizer with promising empirical performance. However, the generalization properties of Katyusha remain largely unexplored. We conjecture that, in the smooth quadratic regime (i.e., under assumptions of strong convexity and smoothness of the loss function, and boundedness of gradients), Katyusha is uniformly stable in the sense of Bousquet and Elisseeff. Instantiating our framework for NAG, we extend the use of Lyapunov …

Oregon State Rank Assessment For Willamette Navarretia (Navarretia Willamettensis), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Willamette Navarretia (Navarretia willamettensis) using NatureServe methodology, 2026.

Assessment Of The Readiness Of Architectural Design Companies To Adopt Eco-Friendly Nanotechnologies In Sustainable Building Design, Ashwaq Essa Al Khalil

Dissertations and Theses

Nanotechnology is emerging as a promising innovation in sustainable architectural design, although its adoption remains slow. Research highlights the advantages of incorporating nanotechnologies in architecture, including improved material performance, enhanced thermal efficiency, reduced energy consumption, improved durability, and progress toward the Sustainable Development Goals (SDGs). These advantages make nanomaterials a promising solution for sustainable building design, particularly in hot-climate regions where energy consumption and carbon emissions associated with conventional building design practices remain major concerns.

Despite this potential, nanotechnology adoption in architecture faces several challenges, including limited real-world applications, slow diffusion in practice, and persistent organizational, economic, and regulatory barriers. …

The Method Of Periodic Averaging Applied To Reduced Coupled Mode Theory Models For Fiber Laser Amplifiers, Rebecca Nicole Bryant

Dissertations and Theses

Fiber laser amplifier (FLA) models are often implemented without rigorous mathematical justification or thorough numerical validation. Without a proper theoretical basis for assumptions and approximations, or a technical analysis of model performance, there is significant uncertainty about the limitations of any given reduced model and its suitability for an application. This research aims to address the lack of comprehensive assessment of FLA models by directly comparing distinct models and recommending a mathematical alternative to replace heuristic model-reduction techniques. The work in this dissertation is divided into two projects: a comparative study that uses existing FLA models to assess the validity …

Shifting Perspectives In Mathematics: Examining Preservice Elementary Teachers' Evolving Conceptions Of Mathematics, Identity, And Social Inequality Through Course Design, Autumn Thu Pham

Dissertations and Theses

Mathematics is often viewed, taught, and learned as an abstract, stand-alone subject, with an emphasis on procedures that are frequently disconnected from learners' lived experiences. Within this framing, limited attention is given to students' affect and identities in relation to mathematics. As a result, opportunities to engage with mathematics as a social, sociopolitical, and empowering tool remain rare. These patterns highlight an important implication for teacher education programs: when mathematics is framed primarily as abstract and procedural, preservice elementary teachers (PTs) may enter the profession lacking strong conceptual understanding, pedagogical flexibility, and the social and political awareness needed to effectively …

Emotion-Focused Teaching And Preschool Children's Social, Emotional, And Self-Regulatory Development, Brielle Emily Petit

Dissertations and Theses

Contributing to the literature on supportive mechanisms for children's development of social, emotional, and self-regulatory competencies, the current study examines the contributions of emotion-focused teaching in preschool classrooms. Emotion-focused teaching is a framework used within preschool classrooms that encompasses three domains of teaching that support children's development of emotion skills—how teachers display their own emotions or emotion-related behaviors and actions (modeling), the ways they respond to children's emotional expressions (responding), and how instruction is used to inform children about emotions and related processes (instructing). More frequent emotion-focused teaching has been shown to be a …

Social Influencers Reduce Infection Burden And Modify Epidemic Lag In Group-Structured Populations, Aja Sutton, Adam Z. Reynolds, Matthew A. Turner, James Holland Jones

Publications, Reports and Presentations

The impact of online social influence on social learning, health behaviour and population health is a new, rapidly developing area of study. Previous research focused specifically on digital influencers suggests they may be able to affect group-level diffusion of health-protective behaviours such that they modify epidemic outcomes. However, formal models have yet to test the intuitive hypothesis that the effect of digital influencers is sufficient to generate tangible real-world effects on epidemics. We develop an agent-based model that incorporates digital influencers into an epidemic scenario to test hypotheses about how competing influence messages affect the diffusion of health-protective behaviours throughout …

Introduction To Mathematical Analysis Ii, Beatriz Lafferriere, Gerardo Lafferriere, Mau Nam Nguyen

PDXOpen: Open Educational Resources

These lecture notes complement the book Introduction to Mathematical Analysis I, Third Edition, with sections on integration, numerical series, series of functions, and selected advanced topics. Together, both volumes support a one semester or two-quarter course on introductory mathematical analysis.

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Modeling Turbulent Accretion Flows Around Black Holes: Azimuthal Flux Derivative Density Curves In 3d Mhd Simulations, Sasmitha Purushothaman, Matthew D. Duez, Pavan Chawhan

University Honors Theses

When modeling two-dimensional axisymmetric accretion disks around Kerr black holes, setting the azimuthal terms of the MHD equations to zero causes the loss of turbulence and dynamo effects. In this paper, we use three-dimensional models to identify the turbulence that arises from azimuthal flux derivatives (AFDs) and create probability density functions to characterize them. We establish a pipeline for calculating the AFDs, creating a distribution, and normalizing it. Then, we plot the dependence of the conditional probability of the AFDs on density, magnetic field strength, and velocity for the continuity and magnetic induction equations. Future research can take this information …

Comparing The Sensitivity And Degree Of Boolean Functions Via The Hypercube, Anne-Caroline Rupp

University Honors Theses

This thesis studies three complexity measures of total Boolean functions f:{0,1}ⁿ → {0,1}: maximum sensitivity s(f), polynomial degree deg(f), and spectral sensitivity λ(f), where λ(f) is defined as the spectral norm of the adjacency matrix of the sensitivity graph. Building on the results of Aaronson et al., we examine the inequality chain √s(f) ≤ λ(f) ≤ deg(f) and investigate whether all three quantities can be simultaneously equal.

The first part of the thesis reverse engineers the equality cases of the two known inequalities to isolate necessary extremal conditions on both the Fourier structure of f and the local geometry …

Not Everyone Gets A Tree: Housing Values, Street Trees, And Equity In Portland, Matthew Moller

University Honors Theses

Street trees are positively associated with Portland home sale prices, but exposure and capitalization are uneven by race/ethnic neighborhood context. Urban trees are ecological assets, but their economic and equity implications remain uneven. This thesis examines street-tree exposure and 2023 residential sale prices in Portland, Oregon (n = 6,414) using a mixed-methodology hedonic design. Ordinary least squares models measure inventoried street-tree counts within 20m, 50m, and 100m buffers together with structural controls and census-block racial and ethnic context. Trees are positively and significantly associated with logged prices at all radii, with scale-sensitive magnitudes and modestly better fit as wider buffers. …

Applications Of Prior And Novel Computational Tools In Mental Health Treatment, And Their Potential To Uncover The Explanatory Gap, Ambika Vyas

University Honors Theses

The explanatory gap is a widely discussed concept in scientific and philosophical literature. In neuroscience, the solution to the explanatory gap is highly sought out, but the general consensus is that it is unsolvable. Numerous articles discuss the explanatory gap alongside computational tools and how these tools could aid neuroscientists in uncovering the mental health explanatory gap. However, significant developments in machine learning have been made since 2020, coinciding with the rise in Large Language Models (LLMs). This thesis is a literature review on computational methods, tools, and devices developed and utilized by researchers to improve how mental health disorders …

Hillslope Aspect And Other Potential Controlling Factors On The Spacing Of Periglacial Stone Stripes In Se Oregon, Blue Hansen

University Honors Theses

Stone stripes are a type of patterned landscape that can be polygenetic in origin, but in the High Lava Plains province are interpreted to be relict periglacial features based on similarities to active stone stripe formation in current periglacial settings. Periglacial stone stripes are hypothesized to form via frost process, including ice-driven cracking and soil heave which is dependent on temperature, long-term differences in temperature may contribute to differences in stone stripe patterns or density. Stone stripes in Oregon and Idaho have previously been studied using field techniques, but there is room for reexamination of temperature controls on hillslope density …

Assessment Of Information Literacy Instruction In Reference: Applying Vanscoy’S Conceptual And Procedural Framework In Practice, Vanessa Arce

Communications in Information Literacy

The instructional aspect of reference work has long been acknowledged, especially in academic libraries. The current RUSA guidelines include helping users develop information literacy as a goal of reference. In this context, investigating the presence and nature of information literacy instruction can be used to assess the quality of reference services. This study applied Amy VanScoy’s conceptual/procedural framework for point-of-need instruction to a sample of chat reference transcripts at Lehman College, City University of New York. One of the assessment’s goals was to determine the prevalence of instruction and type of knowledge addressed in reference interactions. Another goal was to …

Investigating An Energy-Preserving Spectral Finite Difference Numerical Method For A Wave Equation On The Metric Graph, Tue Minh Tran

University Honors Theses

To investigate the accuracy and long-term energy conservation of a spectral finite difference numerical method for a wave equation on metric graphs. In conservative systems, numerical methods should preserve total energy. However, explicit finite difference methods require impractically small space steps and exhibit energy drift at end points. To address these limitations, a spectral finite difference method is implemented using a Fourier transformation. This semi-spectral method improves stability at endpoints while maintaining second-order accuracy, achieving an overall error of O(∆t²). We implement the semi-spectral method on the IEEE14 metric graph and provide visuals showing the initial condition …

Social Determinants As A Predictor For Heart Disease Mortality: Oregon Regional Study, Jewel Jones

University Honors Theses

The study examined the association between selected social determinants of health and heart disease mortality across geographic regions in Oregon. Using a regional analysis design, county-level population and mortality data were grouped into nine geographic regions to evaluate patterns of cardiovascular disease burden across the state. Social determinant variables were obtained from publicly available U.S. Census Bureau datasets and included poverty, crowding among households, single-parent households, lack of broadband internet subscription, housing cost burden, high school diploma attainment, and unemployment.

Heart disease mortality counts per 100,000 population were derived from official birth and death certificate records. Statistical analyses were conducted …

Developing A High-Resolution Off-Axis Common-Mode Digital Holographic Microscope, Lucy Cook

University Honors Theses

Off-axis digital holographic microscopy (DHM) is a powerful tool for 3D, non-invasive live-cell tracking without moving parts. However, traditional setups face an inherent dilemma: split-path interferometers offer high spatial resolution but poor temporal stability, while more stable common-mode configurations are historically limited to lower numerical aperture (NA) regimes. This thesis bridges that gap by scaling a common-mode DHM architecture into a high-resolution benchtop instrument featuring NA = 0.65 objectives, paired with a high-power 520 nm laser source to combat transmission losses and sustain imaging frame rates across an expanded optical footprint. We map the multi-variable design space required to satisfy …

Conello Vendor Marketplace Capstone: A Review On The Capstone Process And Computer Science Degree, Levi Hauck

University Honors Theses

This Capstone Review Thesis discusses the current structure of the Computer Science Degree path and Computer Science Capstone at PSU. This thesis reviews the Conello Vendor Marketplace Capstone, a project designed to help address the issue of teambuilding in the workplace. It points out ways in which teamwork and organization is an underdeveloped skill in Computer Science. During the Capstone project, the project management method of Agile development was recommended and used. However, it became clear that the team, leader included, had a gap in knowledge and skills to be successful, as well as a lack of experience in team …

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad

University Honors Theses

Throughout the Phanerozoic, one of the most successful phyla of marine invertebrates has been Echinodermata. Echinodermata was particularly successful throughout the Paleozoic, with class Crinoidea making up a majority of occurrences. The proportion of echinoderm occurrences that are crinoids declined massively at the end of the Permian and continued to decrease into modern day, never fully recovering. One of the factors thought to have been so important for crinoid success in the Paleozoic and their decreasing success throughout geologic time has been their propensity for success in shallow-marine environments, though crinoids also exist within deep-marine environments. This study seeks to …

Agile In The Age Of Ai: Considerations And Improvements For Streamlining Developer Workflows, Stephen Feng

University Honors Theses

This paper examines the integration of AI language models into Agile developer workflows during a six-month software development project. Using the development of SagacityWall, a mindfulness-based social media application built by a team of eight undergraduates, it identifies three key areas in Agile processes where AI provided meaningful leverage: translating business requirements into actionable developer work tickets, accelerating framework research and technology stack decisions, and reducing onboarding friction through AI-assisted code scaffolding and Behavior-Driven Development story formatting. The study finds that AI meaningfully boosted productivity across these stages – not by replacing developer judgment, but by reducing overhead at each …

The Voice As The Ultimate Microtonal Instrument, Catherine Terrell

University Honors Theses

I wrote several songs in a non-standard tuning system, 19-equal temperament. I define and distinguish 19-equal temperament and 12-equal temperament, then explore why I decided to write in this tuning system. I argue that intonation is a tool composers can implement along with more common musical devices. After describing the methods I used to create this music, I detail how I taught performers to sing it. I then describe and analyze the several works of music I created. Through the compositional process, I found tuning to be a very effective means in expressing musical and poetic ideas.

Oregon State Rank Assessment For Straggling Gilia (Allophyllum Gilioides), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Straggling gilia (Allophyllum gilioides) using NatureServe methodology, 2026.

Isometric Force Characterization Of Braided Pneumatic Actuators, Ben Bolen, Mohammad Elzein, Lawrence Pang, Alexander Hunt

Mechanical and Materials Engineering Faculty Publications and Presentations

Artificial muscles such as braided pneumatic actuators (BPAs) offer many advantages for robotic systems, including high durability and strength-to-weight ratios. However, their use in robotic systems is still extremely limited, in part due to their poor force, length, and pressure characterization. In this work, a test setup is created to compare force produced by Festo fluidic BPAs with leading models. Our analysis of the data has resulted in (1) the development of new equations to calculate force as functions of pressure and contraction for Festo BPAs with uninflated diameters of 10 mm and 20 mm, and (2) a novel equation …

Symmetry And Psychosocial Adaptation To Trauma, Illness And Disability Part I: Views From Physics, Medicine And Psychology, Hanoch Livneh

Leadership, Learning and Counseling Faculty Publications and Presentations

The aim of this two-part paper is to discuss the concept of symmetry and its derivatives, symmetry breaking and asymmetry, and the role they assume in elucidating the structure and processes that underlie psychosocial adaptation to traumatic experiences. To achieve this aim, in Part I, first, a cursory review of symmetry is undertaken as it applies to physics, including conservation laws, the forces of nature, and leading theories of nature. Second, the paper addresses how symmetry is perceived in biology and medicine, including symmetry within biochemical and genetic structures, the human body, and the onset of disease processes. Third, the …