Physical Sciences and Mathematics Commons^™

Aquatic Invasive Species Survey And Treatment On Lake Umatilla And Lake Celilo 2022-2023 Report, Gabriel E. Campbell, Jacob Rose

Center for Lakes and Reservoirs Publications and Presentations

Flowering Rush (Butomus umbellatus) is an invasive aquatic plant in the Pacific Northwest that threatens salmon habitat. The Center for Lakes and Reservoirs staff surveyed for this and other aquatic species from 2022 and 2023 in the Columbia River in Lake Umatilla and Lake Celilo. This document summarizes their survey efforts including their protocols, data, and small-scale removal efforts.

Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung

Physics Faculty Publications and Presentations

The electromagnetic fields generated from a static current source on a spherical surface are calculated in the framework of axion electrodynamics to first order in the coupling parameter. Comparisons of the results are made with reference to various results obtained in conventional Maxwell electrodynamics, as well as previous results obtained for point magnetic dipole source coupled to harmonic axion fields. Distinct features from the results so obtained are highlighted for possible experimental probing of the axions via electromagnetic interactions. In particular, electromagnetic radiation from sources with strong magnetic field is studied which may enable the detection of a cosmic …

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. …

Machine Learning Predictions Of Electricity Capacity, Marcus Harris, Elizabeth Kirby, Ameeta Agrawal, Rhitabrat Pokharel, Francis Puyleart, Martin Zwick

Complex Systems Faculty Publications and Presentations

This research applies machine learning methods to build predictive models of Net Load Imbalance for the Resource Sufficiency Flexible Ramping Requirement in the Western Energy Imbalance Market. Several methods are used in this research, including Reconstructability Analysis, developed in the systems community, and more well-known methods such as Bayesian Networks, Support Vector Regression, and Neural Networks. The aims of the research are to identify predictive variables and obtain a new stand-alone model that improves prediction accuracy and reduces the INC (ability to increase generation) and DEC (ability to decrease generation) Resource Sufficiency Requirements for Western Energy Imbalance Market participants. This …

Isotopic Signature Of Massive, Buried Ice In Eastern Taylor Valley, Antarctica: Implications For Its Origin, Christopher B. Gardner, Melisa A. Diaz, Devin F. Smith, Andrew G. Fountain, Joseph S. Levy, W. Berry Lyons

Geography Faculty Publications and Presentations

The coastal regions of the McMurdo Dry Valleys, Antarctica, contain deposits of the Ross Sea Drift, sedimentary material left from the Ross Sea ice sheet from the advance of the West Antarctic ice sheet during the Last Glacial Maximum. Much of this deposit is ice-cored, but data on the stable isotopic composition of water from this ice, which may contain a valuable climate archive, are sparse or incomplete. Widespread thermokarstic ground subsidence in this “coastal thaw zone” of the McMurdo Dry Valleys suggests that these potential records are rapidly being lost due to the melting of ground ice and permafrost. …

Chemical Elements, Flavor Chemicals, And Nicotine In Unused And Used Electronic Cigarettes Aged 5–10 Years And Effects Of Ph, Monique Williams, Wentai Luo, Kevin J. Mcwhirter, Omeka Ikegbu, Prue Talbot

Chemistry Faculty Publications and Presentations

The concentrations of elements/metals, nicotine, flavor chemicals and acids were compared in the e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5–10 years. Metal analysis was performed using inductively coupled plasma optical emission spectroscopy; nicotine and flavor chemical analyses were performed using gas chromatography/mass spectroscopy. Of the 22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin, zinc) were often found in the e-liquids. Five elements had the highest average concentrations: copper (1161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L). Nicotine concentrations were always lower …

Mussel Squeeze: Dissolved Oxygen And Temperature Can “Squeeze” Zebra Mussels Out Of Invaded Reservoirs, Crysta Gantz, Rich Miller, Steve Wells, Mark D. Sytsma, Angela Strecker

Environmental Science and Management Faculty Publications and Presentations

Zebra mussels (Dreissena polymorpha) are an aquatic invasive species that cause extensive economic and ecological impacts and are a management priority in areas outside of their native range. Survivorship and distribution of zebra mussels within a waterbody are thought to be influenced by temperature and dissolved oxygen conditions, but detailed information to confirm the importance of these environmental controls is necessary to inform management efforts. We measured planktonic zebra mussel veliger density and adult survivorship in San Justo Reservoir in central California to determine distribution and timing of spawning in relation to temperature and dissolved oxygen throughout winter, spring, and …

Spatial Validation Of Agent-Based Models, Kristoffer Wikstrom, Hal T. Nelson

Public Administration Faculty Publications and Presentations

This paper adapts an existing techno–social agent-based model (ABM) in order to develop a new framework for spatially validating ABMs. The ABM simulates citizen opposition to locally unwanted land uses, using historical data from an energy infrastructure siting process in Southern California. Spatial theory, as well as the model’s design, suggest that adequate validation requires multiple tests rather than relying solely on a single test-statistic. A pattern-oriented modeling approach was employed that first mapped real and simulated citizen comments across the US Census tract. The suite of spatial tests included Global Moran’s I, complemented with bivariate correlations, as well as …

Possibilities For Inertial Electrostatic Confinement Fusion, Jeffrey Edward Black

Dissertations and Theses

While most of the fusion energy research is focused on magnetic confinement, there have been several alternative confinement methods aimed at the development of smaller and less expensive reactors. A number of these devices utilize a spherically convergent beam of recirculating ions, a technique known as inertial electrostatic confinement (IEC). This study looks at several aspects of IEC devices, including measurements of the fusion rate of an IEC device with a wire mesh electrode cathode, and a solid titanium cathode. In addition, several computational studies were performed to explore the possibilities for IEC fusion. These include development of a 1D-1P …

Scaling Epa-Rimm With Multicore System Management Interrupt Handlers, Alexander K. Freed

Dissertations and Theses

Continuous runtime integrity measurement mechanisms (RIMMs) can be used for timely detection of kernel and hypervisor rootkits. Researchers have proposed running RIMMs in privileged execution environments, such as the x86 architecture’s System Management Mode (SMM), to detect interference from rootkits that have gained control of the host operating system. However, the extended amount of time in SMM required to perform inspections can cause severe disruption to the host. A previously proposed RIMM design called EPA-RIMM addresses this by decomposing long inspections across multiple System Management Interrupts (SMI), the interrupt used to invoke SMM.

EPA-RIMM is intended for deployment on server-class …

Physical Controls On The Hydrology Of Perennially Ice-Covered Lakes, Taylor Valley, Antarctica (1996-2013), J. M. Cross, Andrew G. Fountain, M. J. Hoffman, M. K. Obryk

Geology Faculty Publications and Presentations

The McMurdo Dry Valleys, Antarctica, are a polar desert populated with numerous closed-watershed, perennially ice-covered lakes primarily fed by glacial melt. Lake levels have varied by as much as 8 m since 1972 and are currently rising after a decade of decreasing. Precipitation falls as snow, so lake hydrology is dominated by energy available to melt glacier ice and to sublimate lake ice. To understand the energy and hydrologic controls on lake level changes and to explain the variability between neighboring lakes, only a few kilometers apart, we model the hydrology for the three largest lakes in Taylor Valley. We …

A First-Tier Framework For Assessing Toxicological Risk From Vaporized Cannabis Concentrates, Shawna Vreeke, David M. Faulkner, Robert Strongin, Echoleah Rufer

Chemistry Faculty Publications and Presentations

Vaporization is an increasingly prevalent means to consume cannabis, but there is little guidance for manufacturers or regulators to evaluate additive safety. This paper presents a first-tier framework for regulators and cannabis manufacturers without significant toxicological expertise to conduct risk assessments and prioritize additives in cannabis concentrates for acceptance, elimination, or further evaluation. Cannabinoids and contaminants (e.g., solvents, pesticides, etc.) are excluded from this framework because of the complexity involved in their assessment; theirs would not be a first-tier toxicological assessment. Further, several U.S. state regulators have provided guidance for major cannabinoids and contaminants. Toxicological risk assessment of cannabis concentrate …

Data From: Machine Learning Predictions Of Electricity Capacity, Marcus Harris, Elizabeth Kirby, Ameeta Agrawal, Rhitabrat Pokharel, Francis Puyleart, Martin Zwick

Complex Systems Faculty Datasets

This research applies machine learning methods to build predictive models of Net Load Imbalance for the Resource Sufficiency Flexible Ramping Requirement in the Western Energy Imbalance Market. Several methods are used in this research, including Reconstructability Analysis, developed in the systems community, and more well-known methods such as Bayesian Networks, Support Vector Regression, and Neural Networks. The aims of the research are to identify predictive variables and obtain a new stand-alone model that improves prediction accuracy and reduces the INC (ability to increase generation) and DEC (ability to decrease generation) Resource Sufficiency Requirements for Western Energy Imbalance Market participants. This …

Enlarging The Stokes Shift By Weakening The Π-Conjugation Of Cyanines For High Signal-To-Noise Ratiometric Imaging, Yongkang Yue, Tingting Zhao, Zhou Xu, Weijie Chi, Xiaojun Chai, Jiahong Ai, Jiawei Zhang, Fangjun Huo, Robert M. Strongin, Caixia Yin

Chemistry Faculty Publications and Presentations

The signal-to-noise ratio (SNR) is one of the key features of a fluorescent probe and one that often defines its potential utility for in vivo labeling and analyte detection applications. Here, it is reported that introducing a pyridine group into traditional cyanine-7 dyes in an asymmetric manner provides a series of tunable NIR fluorescent dyes (Cy-Mu-7) characterized by enhanced Stokes shifts (≈230 nm) compared to the parent cyanine 7 dye (nm). The observed Stokes shift increase is ascribed to symmetry breaking of the Cy-Mu-7 core and a reduction in the extent of conjugation. The fluorescence signals of the Cy-Mu-7 dyes …

Reviving Knowledges Through Play And Resistance: The Case Of Navajo Conceptions Of Space, Daniel Ness, Richard D. Sawyer

Northwest Journal of Teacher Education

The authors explore a possible cause of epistemicidal predispositions of the dominant Eurocentric curricula. They posit that one way to determine a plausible contributing factor of this increasing devastation is to consider epistemicide through the lens of intellectual development. To do this, the authors examine parallel patterns of behavior in the domains of developmental and cognitive psychology. The authors then discuss an alternative framework to the Western conception of space within formal K-12 education by presenting the Navajo conception of space and play. Throughout the paper, the authors argue that all students—and especially those living in poverty in commercially constructed, …

Climate Change Curricula In Alberta, Canada: An Intersectional Framing Analysis, Greg Lowan-Trudeau

Northwest Journal of Teacher Education

This article is comprised of a climate change-focused framing analysis of proposed revisions to Alberta, Canada’s K-6 curriculum as an ideologically motivated manifestation of curricular epistemicide. Eisner’s three curricula—the explicit, implicit, and null—and scholarship related to intersectional climate and environmental justice, education, and communication provide the theoretical framework. This inquiry concludes with a critical discussion of and possible alternatives to the revised curriculum with further consideration of the implications for those involved with similar endeavours in other jurisdictions across Canada and around the world.

Mathematics In The Woods: Exploring Low-Income Parents’ Perceptions Of And Involvement In Their Children’S Mathematical Learning, Lulu Sun

Northwest Journal of Teacher Education

This article features data from a three-day mathematics camping trip that offered parents and their children time and space to enjoy non-digital activities and mathematics-building tasks. Drawing upon data from a larger qualitative study of children and their parents, this article specifically focuses on 10 parents’ perceptions of their children’s mathematics learning, problem-solving, and wellbeing. Findings suggest that, although parents are interested in their children’s mathematics learning, they are most concerned with their children’s development of problem-solving abilities and social skills. Moreover, students’ own learning experience is important for their mathematics learning.

Investigating Small-Group Cognitive Engagement In General Chemistry Learning Activities Using Qualitative Content Analysis And The Icap Framework, Safaa Y. El-Mansy, Jack Barbera, Alissa J. Hartig

Chemistry Faculty Publications and Presentations

The level of students’ engagement during active learning activities conducted in small groups is important to understanding the effectiveness of these activities. The Interactive–Constructive–Active–Passive (ICAP) framework is a way to determine the cognitive engagement of these groups by analyzing the conversations that occur while student groups work on an activity. This study used qualitative content analysis and ICAP to investigate cognitive engagement during group activities in a General Chemistry course at the question level, a finer grain size than previously studied. The analysis determined the expected engagement based on question design and the observed engagement based on group conversations. Comparisons …

Response Of Soil Respiration To Changes In Soil Temperature And Water Table Level In Drained And Restored Peatlands Of The Southeastern United States, E. E. Swails, K. Krauss, Marcelo Ardón, A. L. Peralta, A. M. Helton, Jennifer L. Morse, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

Background

Extensive drainage of peatlands in the southeastern United States coastal plain for the purposes of agriculture and timber harvesting has led to large releases of soil carbon as carbon dioxide (CO2) due to enhanced peat decomposition. Growth in mechanisms that provide financial incentives for reducing emissions from land use and land-use change could increase funding for hydrological restoration that reduces peat CO2 emissions from these ecosystems. Measuring soil respiration and physical drivers across a range of site characteristics and land use histories is valuable for understanding how CO2 emissions from peat decomposition may respond to raising water table levels. …

Most Recent Rupture On The Boulder Creek Fault Triggered Bedrock Landsliding In The Nooksack Watershed, Whatcom County, Washington, Abigail Catherine Underwood

Dissertations and Theses

Catastrophic bedrock landslides with volumes ranging from 10⁶ to 10⁸ m³ contribute to rapid landscape evolution, often resulting in erosion rates that exceed the long-term average rates caused by tectonic uplift. Understanding the spatiotemporal trends of large bedrock landslides helps us understand previous drivers of landscape evolution as well as predict how the landscape will respond in the future. The Nooksack Watershed, Whatcom County, Washington, is particularly susceptible to large slope failures because of its high relief, seismic activity, local geology, and relatively abundant precipitation. Specifically, folded and faulted bedrock structures conducive to landsliding in addition to …

Quantum Key-Length Extension, Joseph Jaeger, Fang Song, Stefano Tessaro

Computer Science Faculty Publications and Presentations

Should quantum computers become available, they will reduce the effective key length of basic secret-key primitives, such as blockciphers. To address this we will either need to use blockciphers with inherently longer keys or develop key-length extension techniques to amplify the security of a blockcipher to use longer keys.

We consider the latter approach and revisit the FX and double encryption constructions. Classically, FX was proven to be a secure key-length extension technique, while double encryption fails to be more secure than single encryption due to a meet-in-the-middle attack. In this work we provide positive results, with concrete and tight …

Filling Critical Gaps In The Space-Time Record Of High Lava Plains And Co-Columbia River Basalt Group Rhyolite Volcanism, Vanessa Marie Swenton, Martin J. Streck, Daniel P. Miggins, William C. Mcintosh

Geology Faculty Publications and Presentations

Miocene rhyolitic volcanism of eastern Oregon, USA, can be divided into two main episodes. Mantle plume upwelling is thought to have generated Columbia River Basalt Group (CRBG) lavas and coeval >16.5−15 Ma silicic volcanism trending north−south from northeast Oregon to northern Nevada. Rhyolite volcanism of the 12−0 Ma High Lava Plains province has been ascribed to either buoyancy-driven westward plume spreading or to slab rollback and mantle convection spanning from southeast Oregon to Newberry Volcano to the west. The apparent ca. 15−12 Ma eruptive hiatus suggests that rhyolites of these provinces were a product of separate processes, yet this gap …

The Consequential Role Of Aesthetics In Forest Fuels Reduction Propensities: Diverse Landowners’ Attitudes And Responses To Project Types, Risks, Costs, And Habitat Benefits, Robert G. Ribe, Max Nielsen-Pincus, Chris Enright, Bart R. Johnson, David Hulse

Environmental Science and Management Faculty Publications and Presentations

Private landowners in the southern Willamette Valley of Oregon, USA were surveyed. The survey queried probabilities of implementing specific fuels reduction projects in extensive areas of specific forest types on their property. The projects were described in relation to the beginning and target forest types, the actions required, costs, and long-term maintenance. Forest types were first rated for scenic beauty and informed levels of wildfire risk reduction, scarce habitat production, and associated property rights risks. Propensities to perform each fuels reduction project were then obtained. These were adversely affected by disbelief in heightened wildfire risks or climate change, higher project …

From Machine Learning To Deep Learning: A Comprehensive Study Of Alcohol And Drug Use Disorder, Banafsheh Rekabdar, David L. Albright, Haelim Jeong, Sameerah Talafha

Computer Science Faculty Publications and Presentations

This study aims to train and validate machine learning and deep learning models to identify patients with risky alcohol and drug misuse in a Screening, Brief Intervention, and Referral to Treatment (SBIRT) program. An observational cohort of 6978 adults was admitted in the western region of Alabama at three medical facilities between January and December of 2019. Data were cleaned and pre-processed using data imputation techniques and an augmented sampling data method. The primary analysis involved the multi-class classification of alcohol and drug misuse. Our study shows that accurate identification of alcohol and drug use screening instrument scores was best …

A Multi-Modal Volumetric Microscope With Automated Sample Handling For Surveying Microbial Life In Liquid Samples, Nathan Oborny, Eugene Serabyn, J. Kent Wallace, Kurt Liewer, Manuel Bedrossian, Stephanie Rider, Chris Lindensmith, Jay Nadeau, Multiple Additional Authors

Physics Faculty Publications and Presentations

In the study of microbial life, microscopy plays a unique role due to its ability to detect ordered structure, motility, and fluorescence signals. As such it has also recently gained attention in the context of searching for extant life on distant Solar System bodies bearing liquid water. In this paper we introduce a multimodal volumetric microscopy system for potential future spaceflight missions that combines digital holographic microscopy (DHM) and volume fluorescence imager (VFI), which are volumetric imaging methods that provide highresolution, high-throughput examination of liquid samples. DHM provides information on the absorption, morphology, and motility of imaged objects without requiring …

Canonical Quantile Regression, Stephen Portnoy

Mathematics and Statistics Faculty Publications and Presentations

In using multiple regression methods for prediction, one often considers the linear combination of explanatory variables as an index. Seeking a single such index when here are multiple responses is rather more complicated. One classical approach is to use the coefficients from the leading Canonical Correlation. However, methods based on variances are unable to disaggregate responses by quantile effects, lack robustness, and rely on normal assumptions for inference. An alternative canonical regression quantile (CanRQ) approach seeks to find the linear combination of explanatory variables that best predicts the τ" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: …

River Discharge Mediates Extent Of Phytoplankton And Harmful Algal Bloom Habitat In The Columbia River Estuary (Usa) During North Pacific Marine Heat Waves, Taylor N. Dodrill, Yangdong Pan, Tawnya D. Peterson

Environmental Science and Management Faculty Publications and Presentations

Marine heat waves (MHWs) have been associated with extensive harmful algal blooms (HABs) in the northeast Pacifc Ocean, but the degree to which these large-scale oceanographic events are mirrored in nearshore environments has not been well established. We compared phytoplankton assemblages in the Lower Columbia River Estuary (LCRE) during two Pacifc MHWs that took place in 2015 and 2019, with observations from 2017, a year with no MHW. These data were paired with environmental data from the summers of 2015–2019 to characterize differences in estuarine conditions during MHWs that promote phytoplankton assemblage transitions and identify HAB-conducive conditions. Bloom densities of …

Herbicide-Resistance In Turf Systems: Insights And Options For Managing Complexity, Jennifer H. Allen, David Ervin, George Frisvold, James T. Brosnan, James D. Mccurdy, Rebecca G. Bowling, Aaron J. Patton, Matthew T. Elmore, Travis W. Gannon, Lambert B. Mccarty, Multiple Additional Authors

Public Administration Faculty Publications and Presentations

Due to complex interactions between social and ecological systems, herbicide resistance has classic features of a “wicked problem.” Herbicide-resistant (HR) Poa annua poses a risk to sustainably managing U.S. turfgrass systems, but there is scant knowledge to guide its management. Six focus groups were conducted throughout the United States to gain understanding of socio-economic barriers to adopting herbicide-resistance management practices. Professionals from major turfgrass sectors (golf courses, sports fields, lawn care, and seed/sod production) were recruited as focus-group participants. Discussions emphasized challenges of the weed management of turfgrass systems as compared to agronomic crops. This included greater time constraints for …

Towards More Equitable And Climate Resilient Communities With Jola Ajibade, Jola Ajibade

PDXPLORES Podcast

In this episode of PDXPLORES, Professor Jola Ajibade discusses research examining how cascading social and environmental hazards might impact communities in the Portland metro region and what policymakers and community members can do to mitigate the risks and promote a more just, livable, and sustainable urban future.

Click on the "Download" button to access the audio transcript.