Physical Sciences and Mathematics Commons^™

An Analysis Of The Reactivation Potential Of A Deep-Seated Landslide In The Oregon Coast Range Under Varying Hydrologic Conditions With Seismic Triggering, Emily E. Smoot

Anthós

Landslides can occur in many locations across the world and have the potential to be extremely destructive if failures occur near populated areas. Failures are most likely to occur on slopes that have already experienced numerous failures. This means they are a considerable hazard, and the risk involved with building in areas that have previously experienced landslides should be adequately understood. This study examines the reactivation potential of a deep-seated landslide located in the Oregon Coast Range. The analysis of this landslide included creating a map of the surface morphology and computing the factor of safety for the deposit using …

Water 4.0, Arthur Preston

OHSU-PSU School of Public Health Annual Conference

A review of local drinking water quality/technologies, and strategies to improve water quality using emerging next generation technology.

Unpacking The Process And Outcomes Of Ethical Markets: A Focus On Certified B Corporations, Renée Bogin Curtis

Dissertations and Theses

The growth in conscious consumption presents an opportunity to 1) better understand the potential outcomes of ethical market practices as a community-advocacy tool and 2) to consider potential policy considerations. The marketplace has increasingly become an arena for social action. This leads to the question of how can markets facilitate ethical business practices and community benefits? The recent rise of social benefit corporations warrants an evaluation of the outcomes of ethically-driven markets. Using a comparative research design and qualitative interview methods, this study examines certified Benefit Corporations (B Corps) in two selected cities: Philadelphia and Portland. Through interviews with B …

Soil Nitrogen Cycling Over Two Decades Following Calcium Treatment In Hubbard Brook Experimental Forest, Nh, Angelina Uribe

Environmental Science and Management Professional Master's Project Reports

A watershed-scale calcium addition experiment at Hubbard Brook Experimental Forest, New Hampshire, was performed in 1999 to better understand how forest ecosystem function and biogeochemistry are affected by changes in pH. Significant increases in forest growth and acid neutralizing capacity of the soil and stream water were reported in the six years following the calcium addition, but the expected stimulation of the nitrogen cycle was not observed. The aims of this study were to 1) examine the 20-year dataset of soil nitrogen dynamics following the experimental calcium addition in the treated watershed and paired reference area to understand longer term …

A Hybrid Lipid Membrane Coating “Shape-Locks” Silver Nanoparticles To Prevent Surface Oxidation And Silver Ion Dissolution, Thomas J. Miesen, Arek M. Engstrom, Dane C. Frost, Ramya Ajjarapu, Rohan Ajjarapu, Citlali Nieves Lira, Marilyn R. Mackiewicz

Chemistry Faculty Publications and Presentations

The controlled synthesis of stable silver nanoparticles (AgNPs), that do not undergo surface oxidation and Ag⁺ ion dissolution, continues to be a major challenge. Here the synthesis of robust hybrid lipid-coated AgNPs, comprised of L-α-phosphatidylcholine (PC) membranes anchored by a stoichiometric amount of long-chained hydrophobic thiols and sodium oleate (SOA) as hydrophobic binding partners, that do not undergo surface oxidation and Ag+ ion dissolution, is described. UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) demonstrate that in the presence of strong oxidants, such as potassium cyanide (KCN), the hybrid lipid-coated AgNPs are stable …

How Long Can Neoliberalism Withstand Climate Crisis?, Julius Mcgee, Patrick Greiner

Urban Studies and Planning Faculty Publications and Presentations

The climate crisis is proving to be antithetical to the neoliberal machines that define current forms of social organization. On the one hand, reducing fossil fuel consumption, the largest contributor to climate change, requires collaborative efforts. These efforts must take into consideration the foundational role of fossil fuels in modern economies. We must acknowledge, for instance, that most peoples’ livelihoods are tethered to fossil fuels, which recent studies have demonstrated is not the result of random historical development but deliberate policy.1 Fossil fuels continue to be used as a form of social domination—a means to expropriate productive and reproductive …

Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns

University Honors Theses

The application of silicon nanoparticles varies from energy storage materials, to drug-delivery, and molecular recognition. Various chemical and physical properties of the Si nanoparticles arise from their morphology. This paper aims to reveal the morphology of Si nanoparticles following magnesiothermic reduction of silica (SiO₂) nanoparticles. Two sets of SiO₂ nanoparticles were used, commercially available NanoXact nanoparticles and laboratory-synthesized Stöber nanoparticles. A Zeiss Sigma VP FEG SEM was used to examine the morphology. Following the magnesiothermic reduction, the nanoparticles were etched with HF. Ten sets of images were taken of both Stöber and NanoXact nanoparticles: 1,2: the SiO …

Workflow Critical Path: A Data-Oriented Path Metric For Holistic Hpc Workflows, Daniel D. Nguyen

Dissertations and Theses

Optimizing scientific application performance in HPC environments is a complicated task which has motivated the development of many performance analysis tools over the past decades. These tools were designed to analyze the performance of a single parallel code using common approaches such as message passing (MPI), multithreading (OpenMP), acceleration (CUDA), or a hybrid approach. However, current trends in HPC such as the push to exascale, convergence with Big Data, and growing complexity of HPC applications and scientific workflows, have created gaps that these performance tools do not cover, particularly involving end-to-end data movement through an end-to-end HPC workflow comprising multiple …

Multiple Diagram Navigation, Hisham Benotman

Dissertations and Theses

Domain novices learning about a new subject can struggle to find their way in large collections. Typical searching and browsing tools are better utilized if users know what to search for or browse to. In this dissertation, we present Multiple Diagram Navigation (MDN) to assist domain novices by providing multiple overviews of the content matter using multiple diagrams. Rather than relying on specific types of visualizations, MDN superimposes any type of diagram or map over a collection of documents, allowing content providers to reveal interesting perspectives of their content. Domain novices can navigate through the content in an exploratory way …

Extensible Performance-Aware Runtime Integrity Measurement, Brian G. Delgado

Dissertations and Theses

Today's interconnected world consists of a broad set of online activities including banking, shopping, managing health records, and social media while relying heavily on servers to manage extensive sets of data. However, stealthy rootkit attacks on this infrastructure have placed these servers at risk. Security researchers have proposed using an existing x86 CPU mode called System Management Mode (SMM) to search for rootkits from a hardware-protected, isolated, and privileged location. SMM has broad visibility into operating system resources including memory regions and CPU registers. However, the use of SMM for runtime integrity measurement mechanisms (SMM-RIMMs) would significantly expand the amount …

Tending The Fire: Wildfire Risk Management At The Interface, Cody Randolph Evers

Dissertations and Theses

Escalating loss from wildfire in the American West has made clear the need to rethink wildfire risk, including how such risks result from the unique interaction of social and natural dynamics within the wildland urban interface. Unfortunately, techniques for studying these interactions remain limited. The intent of this research is to address this gap. In each of four chapters, I examine different aspects of wildfire risk management through a coupled human-natural lens. I document how wildfire activity has shifted over three decades across forest and shrubland systems in the western US and connect these changes to the simultaneous growth in …

Modeling And Visualizing Power Amplification In Fiber Optic Cables, Gil Parnon

University Honors Theses

Transverse mode instability in fiber optic cables causes power amplification to exhibit chaotic behavior. Due to this, numerical modeling of fiber optic power amplification is extremely computationally expensive. In this paper I work through modeling similar behavior in a simpler system. I also visualize the three-dimensional phase portrait of the system in order to better understand the behavior and hopefully relate it to more well-understood problems.

Multilevel Spectral Coarsening For Graph Laplacian Problems With Application To Reservoir Simulation, Andrew T. Barker, Stephen V. Gelever, Chak Shing Lee, Sarah Osborn, Panayot S. Vassilevski

Mathematics and Statistics Faculty Publications and Presentations

We extend previously developed two-level coarsening procedures for graph Laplacian problems written in a mixed saddle point form to the fully recursive multilevel case. The resulting hierarchy of discretizations gives rise to a hierarchy of upscaled models, in the sense that they provide approximation in the natural norms (in the mixed setting). This property enables us to utilize them in three applications: (i) as an accurate reduced model, (ii) as a tool in multilevel Monte Carlo simulations (in application to finite volume discretizations), and (iii) for providing a sequence of nonlinear operators in a full approximation scheme for solving nonlinear …

Detecting Geomorphic Change And Stream Channel Evolution On The Sandy River, Oregon, Using Lidar Following Dam Removal In 2007, Lowell Henry Anthony

Dissertations and Theses

Following the removal of Marmot Dam on the Sandy River, Oregon, several Lidar flights were flown over the area of the former reservoir. The resultant sequential DEMs permitted calculation of reach-scale volumetric erosion and aggradation following dam removal. This allows for change detection across the entire affected reach of the former impoundment rather than just at several cross sections. In the first year there was a net loss of blank sediment in the dewatered reach. Subsequent flights show continued degradation of 145,649 m³ as well as aggradation of 6,232 m³. Sediment transport reached quasi-equilibrium in 2012 with …

Balancing Security, Performance And Deployability In Encrypted Search, David Joel Pouliot

Dissertations and Theses

Encryption is an important tool for protecting data, especially data stored in the cloud. However, standard encryption techniques prevent efficient search. Searchable encryption attempts to solve this issue, protecting the data while still providing search functionality. Retaining the ability to search comes at a cost of security, performance and/or utility.

An important practical aspect of utility is compatibility with legacy systems. Unfortunately, the efficient searchable encryption constructions that are compatible with these systems have been proven vulnerable to attack, even against weaker adversary models.

The goal of this work is to address this security problem inherent with efficient, legacy compatible …

Interactions Between The Azoarcus Ribozyme And Manganese (Ii) Divalent Cations, Joshua Martwick

University Honors Theses

The RNA world hypothesis suggests that RNA systems were the first form of life on the planet, beginning to appear approximately 4 billion years ago. Group I introns are self-splicing RNA elements in extant organisms and use Mg²⁺ as the principle divalent cation to promote catalysis. The group I intron ribozyme from Azoarcus is frequently used in origin of life studies, partially due to its autocatalytic abilities - the Azoarcus ribozyme is able to be broken into fragments and reassemble itself into its fully functional ribozyme. Previous work identified metal binding sites on the Azoarcus ribozyme which use both …

Some New Results On Stochastic Comparisons Of Coherent Systems Using Signatures, Ebrahim Amini-Seresht, Baha-Eldin Khaledi, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

We consider coherent systems with independent and identically distributed components. While it is clear that the system’s life will be stochastically larger when the components are replaced with stochastically better components, we show that, in general, similar results may not hold for hazard rate, reverse hazard rate, and likelihood ratio orderings. We find sufficient conditions on the signature vector for these results to hold. These results are combined with other well-known results in the literature to get more general results for comparing two systems of the same size with different signature vectors and possibly with different independent and identically distributed …

Toxic Ketene Gas Forms On Vaping Vitamin E Acetate Prompting Interest In Its Possible Role In The Evali Outbreak, Robert Strongin

Chemistry Faculty Publications and Presentations

Recent efforts by the Centers for Disease Control and Prevention (CDC), the US Food and Drug Administration (FDA), and state authorities have led to the determination that vitamin E acetate (VEA) is strongly associated with e-cigarette or vaping product use-associated lung injury (EVALI) (1). VEA has been found in nearly all patient lung fluid samples analyzed and not observed in lung fluid from healthy cohorts. Despite strong evidence linking VEA to EVALI, its putative role as a causative agent has yet to be determined. To address the key issue of whether VEA is a just marker or a significant mediator …

Dictionary Learning For Image Reconstruction Via Numerical Non-Convex Optimization Methods, Lewis M. Hicks

University Honors Theses

This thesis explores image dictionary learning via non-convex (difference of convex, DC) programming and its applications to image reconstruction. First, the image reconstruction problem is detailed and solutions are presented. Each such solution requires an image dictionary to be specified directly or to be learned via non-convex programming. The solutions explored are the DCA (DC algorithm) and the boosted DCA. These various forms of dictionary learning are then compared on the basis of both image reconstruction accuracy and number of iterations required to converge.

The Rise And Infiltration Of Pac-Man And Street Fighter, Angelic Phan

University Honors Theses

With the social, cultural, and economic influence of video games, it is important to examine why they have become such popular forms of entertainment. Particularly, why certain franchises have continued to persist among the growing industry. Two notable franchises are Pac-Man and Street Fighter, which are also most frequently discussed in scholarly texts. I supplement a literature review with an analysis of marketing texts to illuminate a series of shared factors that help explain both games' popularity despite the apparent dissimilarities of their content. First, my work helps us look across multiple scholarly papers to create a bigger picture …

Modeling Post-Fire Successional Trajectories Under Climate Change In Interior Alaska Using Landis Ii, Shelby A. Weiss

Systems Science Friday Noon Seminar Series

Alaska boreal forest ecosystems are experiencing a greater frequency of wildfire relative to the region’s historic fire regime. These increases in fire frequency, as well as annual burned area, increase the probability of forests re-burning within shorter intervals than were experienced historically. Such changes to the fire regime have the potential to shift successional trajectories in this ecosystem. To better understand potential changes in vegetation composition following short-interval, repeat fires, we are using LANDIS-II, a forest landscape model, to simulate changes in forest composition in response to climate change and increasing fire frequency. This seminar will include a description of …

Novel View Synthesis In Time And Space, Simon Niklaus

Dissertations and Theses

Novel view synthesis is a classic problem in computer vision. It refers to the generation of previously unseen views of a scene from a set of sparse input images taken from different viewpoints. One example of novel view synthesis is the interpolation of views in between the two images of a stereo camera. Another classic problem in computer vision is video frame interpolation, which is important for video processing. It refers to the generation of video frames in between existing ones and is commonly used to increase the frame rate of a video or to match the frame rate to …

Assessing Differences Between Three Virtual General Chemistry Experiments And Similar Hands-On Experiments, Cory Hensen, Gosia Glinowiecka-Cox, Jack Barbera

Chemistry Faculty Publications and Presentations

To date the efficacy of virtual experiments is not well understood. To better understand what differences may exist between a hands-on learning environment and a virtual learning environment, three experiments were chosen for investigation. For each experiment, approximately half of the students completed a hands-on version of the experiment and the other half completed a virtual version. After completing the given experiment, students were compared on: their ability to meet the learning objectives for that experiment, their responses to six affective scales, and their grade on a laboratory report. Differences were found on four learning objectives. Two of these learning …

Groomed Jet Mass At High Precision, Adam Kardos, Andrew J. Larkoski, Zoltán Trócsányi

Portland Institute for Computational Science Publications

We present predictions of the distribution of groomed heavy jet mass in electron-positron collisions at the next-to-next-to-leading order accuracy matched with the resummation of large logarithms to next-to-next-to-next-to-leading logarithmic accuracy. Resummation at this accuracy is possible through extraction of necessary two-loop constants and three-loop anomalous dimensions from fixed-order codes.

Two- And Three-Loop Data For Groomed Jet Mass, Adam Kardos, Andrew J. Larkoski, Zoltán Trócsányi

Portland Institute for Computational Science Publications

We discuss the status of resummation of large logarithmic contributions to groomed event shapes of hadronic final states in electron-positron annihilation. We identify the missing ingredients needed for next-to-next-to-next-to-leading logarithmic (NNNLL) resummation of the mMDT groomed jet mass in e⁺e⁻ collisions: the low-scale collinear-soft constants at two-loop accuracy, c⁽²⁾_Sc, and the three-loop non-cusp anomalous dimension of the global soft function, γ⁽²⁾_S. We present a method for extracting those constants using fixed-order codes: the EVENT2 program to obtain the color coefficients of c⁽²⁾_Sc, and MCCSM for extracting γ^{(2) …}

Teaching Doppler Ultrasound In An Introductory Laboratory For Pre-Health Students, Theodore Stedmark, Thomas Allen, Ralf Widenhorn

Physics Faculty Publications and Presentations

We present a novel activity to demonstrate the Doppler shift of a sound wave, incident at an angle, upon a moving reflector. This activity is intended for use in an introductory physics laboratory focused on preparing students for the health and medical fields. The activity is designed to simulate Doppler velocity measurements from ultrasound imaging. While there have been previous qualitative discussions of blood flow measurements in the physics education literature, they were without associated laboratory activities.1 The lab can be part of a life science physics curriculum that has been identified in need of reforms to meet the …

An Essay On Proof, Conviction, And Explanation: Multiple Representation Systems In Combinatorics, Elise Nicole Lockwood, John Caughman, Keith Weber

Mathematics and Statistics Faculty Publications and Presentations

There is a longstanding conversation in the mathematics education literature about proofs that explain versus proofs that only convince. In this essay, we offer a characterization of explanatory proofs with three goals in mind. We first propose a theory of explanatory proofs for mathematics education in terms of representation systems. Then, we illustrate these ideas in terms of combinatorial proofs, focusing on binomial identities. Finally, we leverage our theory to explain audience-dependent and audience-invariant aspects of explanatory proof. Throughout, we use the context of combinatorics to emphasize points and to offer examples of proofs that can be explanatory or only …

Fatty Acid Stable Isotopes Add Clarity, But Also Complexity, To Tracing Energy Pathways In Aquatic Food Webs, Ariana M. Chiapella, Martin J. Kainz, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Tracing the flow of dietary energy sources, especially in systems with a high degree of omnivory, is an ongoing challenge in ecology. In aquatic systems, one of the persistent challenges is in differentiating between autochthonous and allochthonous energy sources to top consumers. Bulk carbon stable isotope values of aquatic and terrestrial prey often overlap, making it difficult to delineate dietary energy pathways in food webs with high allochthonous prey subsidies, such as in many northern temperate waterbodies. We conducted a feeding experiment to explore how fatty acid stable isotopes may overcome the challenge of partitioning autochthonous and allochthonous energy pathways …

Reshuffling The Columbia River Basalt Chronology — Picture Gorge Basalt, The Earliest- And Longest-Erupting Formation, Emily B. Cahoon, Martin J. Streck, Anthony A.P. Koppers, Daniel P. Miggins

Geology Faculty Publications and Presentations

The Columbia River Basalt Group (CRBG) is the world’s youngest continental flood basalt province, presumably sourced from the deep-seated plume that currently resides underneath Yellowstone National Park in the northwestern United States. The earliest-erupted basalts from this province aid in understanding and modeling plume impingement and the subsequent evolution of basaltic volcanism. We explore the Picture Gorge Basalt (PGB) formation of the CRBG, and discuss the location and geochemical significance in a temporal context of early CRBG magmatism. We report new ARGUS-VI multicollector 40Ar/39Ar incremental heating ages from known PGB localities and additional outcrops that we can geochemically classify as …

Before And After The Storm: Interactions Between Tree-Fall Canopy Gaps, Plant Phenology, And Frugivorous Lemurs In Masoala National Park, Madagascar, Monica Sue Mogilewsky

Dissertations and Theses

Madagascar is one of Earth's top biodiversity hotspots, with 80% of life on the island considered endemic. Among the endemic species are lemurs, a diverse group of non-human primates. Unfortunately, Madagascar's diversity, including lemurs, is threatened by habitat degradation and loss. Despite intense anthropogenic pressure over the past 50 years, scientists have not detected any lemur extinctions during this period. Some researchers have proposed that lemurs' adaptations to natural disturbances have provided these taxa resiliency against anthropogenic disturbances. Certainly, Madagascar experiences an extreme disturbance regime: the island experiences an average of over three cyclones a year. These cyclones create numerous, …