Digital Commons Network^™

Tools For Quantifying Bacterial Motility Using Digital Holographic Microscopy As Applied To Studying The Simulated Microgravity Environment, Jacqueline Marie Acres

Dissertations and Theses

Digital holographic microcopy (DHM) is a label-free technique that has gained attention in recent years as a tool for volumetric imaging. One application of DHM is for the study of microbial motility with the advantage being that organisms may freely move within their environment. Images created from DHM are in the form of holograms. Holograms are time recordings showing XY information with the Z information contained within. Z information can be retrieved from the holograms directly through a variety of numerical techniques or through reconstruction. Datasets generated from DHM are large and processing remains a challenging task. Here, we show …

Surface Roughness Prediction In End Milling Processes Considering The Vibration Of The Cutting Tool, Yubin Lee

Dissertations and Theses

Purpose: Machining is a manufacturing process for making the desired design with dimensional tolerance and surface roughness. Despite the development of engineering technology, predicting machined surface roughness is still challenging since there are various factors, such as material properties, tool material properties, the rigidity of the machine tool, and the use of coolant. In particular, tool vibration is the most critical factor since it makes it challenging to obtain the desired quality of the machined product by unintentionally making a tool move. Therefore, surface finish was explored in this study, considering cutting tool vibration under various axial depth-of-cuts and feed …

Design And Optimization With Quantum And Memristor Platforms, Yiwei Li

Dissertations and Theses

The complexity and diversity of modern computing challenges have made it difficult for traditional computers to efficiently handle tasks such as computer-aided design, design optimization, and combinatorial problems within a reasonable time frame. In applications such as bitcoin mining and robotic control, power consumption and circuit size are critical factors. To overcome these limitations, this dissertation examines alternative computing technologies such as quantum computers and hybrid memristive circuits. The research demonstrates that these technologies hold the potential to offer more efficient and effective solutions for particular problems, whether in terms of faster computation or reduced power consumption.

Navigating The Transition: Strategies For Supporting The Success Of At-Risk Youth From Middle School To High School And Beyond, Jessica L. Hlavinka

University Honors Theses

It has been demonstrated that small class sizes are beneficial for at-risk students transferring to high school. With fewer students, teachers are better able to give personalized attention and assistance, which can encourage students' engagement and motivation to study. Small class numbers can also foster a feeling of community and belonging, which is essential for at-risk students who may feel alienated at school. Also shown to be successful in assisting at-risk adolescents with the transition to high school are mentoring programs. High school students can get assistance and support from mentors as they negotiate the obstacles of the academic environment. …

Microbial Motility At The Bottom Of North America: Digital Holographic Microscopy And Genomic Motility Signatures In Badwater Spring, Death Valley National Park, Carl Snyder, Jakob P. Centlvre, Shrikant Bhute, Jay Nadeau, Multiple Additional Authors

Physics Faculty Publications and Presentations

Motility is widely distributed across the tree of life and can be recognized by microscopy regardless of phylogenetic affiliation, biochemical composition, or mechanism. Microscopy has thus been proposed as a potential tool for detection of biosignatures for extraterrestrial life; however, traditional light microscopy is poorly suited for this purpose, as it requires sample preparation, involves fragile moving parts, and has a limited volume of view. In this study, we deployed a field-portable digital holographic microscope (DHM) to explore microbial motility in Badwater Spring, a saline spring in Death Valley National Park, and complemented DHM imaging with 16S rRNA gene amplicon …

A Simple In Situ Method For Optimizing Settings For The Einzel Lens Elements In A Focused Ion Beam, Rich Swinford, Erik Sanchez

Physics Faculty Publications and Presentations

Ion beams have had an incredible impact on research in the past couple of decades. One major reason for this is the continued development of systems having optimal beam currents that allows one to image more clearly at different spot sizes to include higher currents that allow for faster milling. The advancements for Focused ion beam (FIB) columns have developed rapidly due to the computational optimization of lens designs. However, once a system has been produced, the optimal column settings for these lenses may change or simply become obscure. Our work involves regaining this optimization with the newly applied values …

Exploring Perspectives On Social And Emotional Learning Programs In Schools, Gina N. Carruth

University Honors Theses

This study explores different viewpoints on the implementation of social and emotional learning (SEL) programs in schools. Using a literature review approach, information was collected through peer-reviewed and online articles to examine the benefits and potential challenges of SEL programs in promoting students' social and emotional development. The findings reveal that while there is widespread support for SEL programs, there are also concerns about its implementation, effectiveness, and potential unintended consequences. This study contributes to the field by highlighting the need for a more nuanced and critical understanding of SEL programs, and their impact on students as well as insight …

A Representation For Many Player Generalized Divide The Dollar Games, Garrison Greenwood, Daniel Ashlock

Electrical and Computer Engineering Faculty Publications and Presentations

Divide the dollar is a simplified version of a two player bargaining problem game devised by John Nash. The generalized divide the dollar game has n > 2 players. Evolutionary algorithms can be used to evolve individual players for this generalized game but representation—i.e., a genome plus a move or search operator(s)—must be carefully chosen since it affects the search process. This paper proposes an entirely new representation called a demand matrix. Each individual in the evolving population now represents a collection of n players rather than just an individual player. Players use previous outcomes to decide their choices (bids) in …

Thin Film Deposition Of Mop, A Topological Semimetal, Robert Browning, Paul Plachinda, Raj Solanki

Physics Faculty Publications and Presentations

MoP is a topological semimetal which has drawn attention due to its unique electrical and optical properties resulting from massless electrons. In order to utilize these properties for practical applications, it is necessary to develop a technique to produce high-quality, large-scale thin films of this 2D material. We report below our initial results of growth of MoP thin films using atomic layer deposition (ALD), where the film grows layer-by-layer. These films were grown on 5 cm × 5 cm silicon oxide coated Si wafers. Resistivity versus temperature measurements show that these films are metallic and includes a partial superconducting phase. …

Picture Gorge Basalt: Internal Stratigraphy, Eruptive Patterns, And Its Importance For Understanding Columbia River Basalt Group Magmatism, Emily Bogdan Cahoon, Martin J. Streck, Anthony A.P. Koppers

Geology Faculty Publications and Presentations

The Picture Gorge Basalt (PGB) of the Columbia River Basalt Group (CRBG) has been previously thought to be limited in its eruptive volume (<3000 >km³) and thought to not extend far from its type locality. At present, PGB represents only 1.1 vol% of the CRBG with a relatively limited spatial distribution of ~10,000 km². New age data illustrate that the PGB is the earliest and longest eruptive unit compared to other main-phase CRBG formations and that some dated basaltic flows reach far (~100 km) beyond the previously mapped extent. This study focuses on extensive outcrops of …

Faculty Senate Monthly Packet February 2023, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The February 6, 2023 Monthly packet includes the February agenda and appendices and the Faculty Senate minutes and attachments from the meeting held January 9, 2023.

Words And Diagrams About Rosenstock-Huessy’S Cross Of Reality, Martin Zwick

Complex Systems Faculty Publications and Presentations

This paper is a systems theoretic examination of Eugen Rosenstock-Huessy’s “cross of reality,” a structure that fuses a spatial dyad of inner-outer and a temporal dyad of past-future into a space-time tetrad. This structure is compatible not only with the "human-centered" point of view that Rosenstock-Huessy favours, but also with the "world-centered" point of view inherent in science. The structure, based in his analysis of speech, is applied by him to a wide variety of individual and collective human phenomena, including language, religion, and social critique. To appropriate terminology used by physicists, the cross of reality could be viewed as …

Systems Thinking Activities Used In K-12 For Up To Two Decades, Diana Fisher, Systems Thinking Association

Complex Systems Faculty Publications and Presentations

Infusing systems thinking activities in pre-college education (grades K-12) means updating precollege education so it includes a study of many systemic behavior patterns that are ubiquitous in the real world. Systems thinking tools include those using both paper and pencil and the computer and enhance learning in the classroom making it more student-centered, more active, and allowing students to analyze problems that have been heretofore beyond the scope of K-12 classrooms. Students in primary school have used behavior over time graphs to demonstrate dynamics described in story books, like the Lorax, and created stock-flow diagrams to describe what was needed …

Long-Term Phosphorus Reduction And Phytoplankton Responses In An Urban Lake (Usa), Yuan Xiao Grund, Yangdong Pan, Mark Rosenkranz, Eugene Foster

Environmental Science and Management Faculty Publications and Presentations

Eutrophication is one of the primary factors causing harmful cyanobacteria blooms in freshwater lakes. This study investigated the long-term changes in water quality and summer phytoplankton assemblages in Oswego Lake, OR, USA, in relation to phosphorus reduction through hypolimnetic aeration and alum applications. Both water quality and phytoplankton assemblages were sampled biweekly during the summers from 2001 to 2013. The concentrations of total phosphorus, soluble reactive phosphorus, and total nitrogen decreased 66%, 93% and 31%, respectively, in response to the hypolimnetic aeration and alum treatments since 2005. Summer phytoplankton assemblages showed a 62% reduction of cyanobacteria biovolume and a …

Columbia River Rhyolites: Age-Distribution Patterns And Their Implications For Arrival, Location, And Dispersion Of Continental Flood Basalt Magmas In The Crust, Martin J. Streck, Vanessa M. Swenton, William C. Mcintosh, Matt Heizler

Geology Faculty Publications and Presentations

Columbia River province magmatism is now known to include abundant and widespread rhyolite centers even though the view that the earliest rhyolites erupted from the McDermitt Caldera and other nearby volcanic fields along the Oregon–Nevada state border has persisted. Our study covers little-studied or unknown rhyolite occurrences in eastern Oregon that show a much wider distribution of older centers. With our new data on distribution of rhyolite centers and ages along with literature data, we consider rhyolites spanning from 17.5 to 14.5 Ma of eastern Oregon, northern Nevada, and western Idaho to be a direct response to flood basalts of …

Nanoscale Hafnium Metal-Organic Frameworks Enhance Radiotherapeutic Effects By Upregulation Of Type I Interferon And Tlr7 Expression, Eunseo Choi, Madeleine R. Landry, Nathan Pennock, Katherine Weinfurter, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Recent preclinical and clinical studies have highlighted the improved outcomes of combination radiotherapy and immunotherapy. Concurrently, the development of high-Z metallic nanoparticles as radiation dose enhancers has been explored to widen the therapeutic window of radiotherapy and potentially enhance immune activation. In this study, we evaluate folate-modified hafnium-based metal-organic frameworks (HfMOF-PEG-FA) in combination with imiquimod, a TLR7 agonist, as a well-defined interferon regulatory factor (IRF) stimulator for local antitumor immunotherapy. The enhancement of radiation dose deposition by HfMOF-PEG-FA and subsequent generation of reactive oxygen species (ROS) deregulates cell proliferation and increases apoptosis. HfMOF-PEG-FA loaded with imiquimod (HfMOF-PEG-FA@IMQ) increases DNA double-strand …

Looking Backward And Forward: Volcanology In The Years 2000, 2010, 2020, And Beyond, Jonathan Fink, Katharine Cashman

Geology Faculty Publications and Presentations

Figuring out how volcanoes work is one of the geoscience’s most complex puzzles. Clues of all sizes, shapes, and colors are scattered across every continent, the bottom of the ocean, in the atmosphere, and on the surfaces of other planets. Generations of geologists, geophysicists, geodesists, and geochemists have used field observations, laboratory measurements, and theory to fill gaps left by their predecessors. Yet critical uncertainties remain. Why do eruptions begin? What determines their intensity? What controls their frequency and style of activity? What causes them to end? These unsolved issues leave society increasingly vulnerable to volcanic disruptions. Hundreds of published …

Cementation And Groundwater Chemistry In Pleistocene Paleodune Deposits Of The Central Oregon Coast, Adrienne Lynn Stephens

Dissertations and Theses

Pleistocene paleodune deposits occur along the Oregon coast, underlying coastal towns, roadways, and associated power and water infrastructure(s). Secondary cementation within these deposits provides some stability, allowing for near-vertical sea cliffs and roadcut outcrops. Yet, slope instability is a prevalent hazard observed within the paleodune deposits. Weakening of cementing agents via changes to groundwater conditions due to altered vegetation, climate change, or contamination, for example, could promote slope instability, threatening lives and infrastructure. This study aims to investigate the variability in the type and degree of cementation and to determine how they are affected by changes in groundwater conditions.

To …

Comparing The Performance Of Different Machine Learning Models In The Evaluation Of Solder Joint Fatigue Life Under Thermal Cycling, Jason Scott Ross

Dissertations and Theses

Predicting the reliability of board-level solder joints is a challenging process for the designer because the fatigue life of solder is influenced by a large variety of design parameters and many nonlinear, coupled phenomena. Machine learning has shown promise as a way of predicting the fatigue life of board-level solder joints. In the present work, the performance of various machine learning models to predict the fatigue life of board-level solder joints is discussed. Experimental data from many different solder joint thermal fatigue tests are used to train the different machine learning models. A web-based database for storing, sharing, and uploading …

Organizational Readiness Assessment For Fraud Detection And Prevention: Case Of Airlines Sector And Electronic Payment, Sultan Ayed Alghamdi

Dissertations and Theses

Payment processing systems have advanced significantly in the airline business. Because e-payments are easy, they have captured the attention of many companies in the aviation industry and are quickly becoming the dominant means of payment. However, as technology advances, fraud grows at a comparable rate. Over the years, there has been a surge in payment fraud incidents in the airline sector, reducing the platform's trustworthiness. Despite attempts to eliminate e-payment fraud, decision-makers lack the technical expertise required to use the finest fraud detection and prevention assessments; this research recognizes the lack of an established decision model as a hurdle and …

Teaching Routines And Student-Centered Mathematics Instruction: The Essential Role Of Conferring To Understand Student Thinking And Reasoning, Eva Thanheiser, Kathleen Melhuish

Mathematics and Statistics Faculty Publications and Presentations

We compare two lessons with respect to how a teacher centers student mathematical thinking to move instruction forward through enactment of five mathematically productive teaching routines: Conferring To Understand Student Thinking and Reasoning, Structuring Mathematical Student Talk, Working With Selected and Sequenced Student Math Ideas, Working with Public Records of Students’ Mathematical Thinking, and Orchestrating Mathematical Discussion. Findings show that the lessons differ in the enactment of teaching routines, especially Conferring to Understand Student Thinking and Reasoning which resulted in a difference in student-centeredness of the instruction. This difference highlights whose mathematics was being centralized in the classroom and whether …

Damage Detection In Reinforced Concrete Member Using Local Time-Frequency Transform Applied To Vibration Measurements, Ning Liu, Thomas Schumacher, Yan Li, Lina Xu, Bo Wang

Civil and Environmental Engineering Faculty Publications and Presentations

Signal processing and analysis of structural vibration measurements are key components of structural damage detection (SDD) in structural health monitoring (SHM). The goal of signal processing is to extract subtle changes in the measured signals, which can be used to infer changes in structural parameters and damage. Time-frequency analysis is one of the most popular characterization methods for studying non-stationary vibration signals. In this article, the local time-frequency transform (LTFT) is applied and evaluated to calculate the time-domain signals because of its excellent time-frequency energy distribution properties. The LTFT matches the input data by the Fourier basis in an inverse …

Native Seed Germination Trials At The Rae Selling Berry Seed Bank, Garbiel E. Campbell, Roxy Olsson, April Hersey, Stephanie Meikle, Kris Freitag

Rae Selling Berry Seed Bank and Plant Conservation Program

This presentation is a summary of germination trials on seeds native to the Pacific Northwest.

Data From: The Geography Of Glaciers And Perennial Snowfields In The American West, Andrew G. Fountain, Bryce Glenn, Hassan J. Basagic

Geology Faculty Datasets

A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years,1955–1990.

Bulletin: General Catalog Issue 2023-2024, Portland State University

Bulletin & Curriculum Change Documents

No abstract provided.

Engram, Vol. 2 2023, Portland State University. School Of Art + Art History + Design

Engram: A Journal of Art History Student Writing

• Editorial Foreword, Hailey Brink

• Reading Queerness in Hilma af Klint’s Diagrammatic Abstractions, Ana Bane

• Opus Anglicanum and May Morris: An Art Historical Study in Meaning Through Time, Rose Caughie

• The Development of El Greco’s Technique Through Mary Magdalen, Natalie Dunlap

• The Great Gold Belt Buckle of Sutton Hoo: A Look at Scandinavian Influence on Anglo-Saxon Style, Elizabeth Hines

• The Late Avar Treasure of Nagyszentmiklos, Ashley Hood

• Demystifying the Authorship of Artemisia Gentileschi’s 1622 Susanna and the Elders Aaron, Lindsay Wilson

• Research-Based Fiction: Redemption in Ruins, John Hooley

Stability Of Structure-Aware Taylor Methods For Tents, Jay Gopalakrishnan, Zheng Sun

Mathematics and Statistics Faculty Publications and Presentations

Structure-aware Taylor (SAT) methods are a class of timestepping schemes designed for propagating linear hyperbolic solutions within a tent-shaped spacetime region. Tents are useful to design explicit time marching schemes on unstructured advancing fronts with built-in locally variable timestepping for arbitrary spatial and temporal discretization orders. The main result of this paper is that an s-stage SAT timestepping within a tent is weakly stable under the time step constraint

∆t ≤ Ch^1+1/s , where ∆t is the time step size and h is the spatial mesh size. Improved stability properties are also presented for high-order SAT time discretizations coupled …

Chemical Reaction Networks In A Laplacian Framework, J.J.P. Veerman, T. Whalen-Wagner, Ewan Kummel

Mathematics and Statistics Faculty Publications and Presentations

The study of the dynamics of chemical reactions, and in particular phenomena such as oscillating reactions, has led to the recognition that many dynamical properties of a chemical reaction can be predicted from graph theoretical properties of a certain directed graph, called a Chemical Reaction Network (CRN). In this graph, the edges represent the reactions and the vertices the reacting combinations of chemical substances. In contrast with the classical treatment, in this work, we heavily rely on a recently developed theory of directed graph Laplacians to simplify the traditional treatment of the so-called defi- ciency zero systems of CRN theory. …

Multicopter Drone Mass Distribution Impacts On Viability, Performance, And Sustainability, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

This short communication highlights the value of drone mass and its distribution, a topic that despite its importance has received scant attention in the rapidly growing drone literature. In particular, the focus is on the impact of mass distribution on drone viability, performance, and sustainability.

Dependence Among Order Statistics For Time-Transformed Exponential Models, Subhash C. Kochar, Fabio Spizzichino

Mathematics and Statistics Faculty Publications and Presentations

Let (X1, . . . ,Xn) be a random vector distributed according to a time-transformed exponential model. This is a special class of exchangeable models, which, in particular, includes multivariate distributions with Schur-constant survival functions and with identical marginals. Let for 1 ≤ i ≤ n, Xi:n denote the corresponding ith order statistic. We consider the problem of comparing the strength of dependence between any pair of Xi’s with that of the corresponding order statistics. It is proved that for m = 2, . . . , n, the dependence of X2:m on X1:m is more than that of X2 …