Physical Sciences and Mathematics Commons^™

Effects Of Environmentally Relevant Concentrations Of Microplastic Fibers On Pacific Mole Crab (Emerita Analoga) Mortality And Reproduction, Dorothy Horn, Elise F. Granek, Clare Steele

Environmental Science and Management Faculty Publications and Presentations

Microplastics are ubiquitous in marine systems; however, knowledge of the effects of these particles on marine fauna is limited. Ocean-borne plastic debris accumulates in littoral ecosystems worldwide, and invertebrate infauna inhabiting these systems can ingest small plastic particles and fibers, mistaking them for food. We examined the effect of microplastic fibers on physiological and reproductive outcomes in a nearshore organism by exposing Pacific mole crabs (Emerita analoga) to environmentally relevant concentrations of microsized polypropylene rope fibers. We compared adult gravid female crab mortality, reproductive success, and embryonic developmental rates between microfiber-exposed and control crabs. Pacific mole crabs exposed to polypropylene …

Topological Magnetoelectric Effect As Probed By Nanoshell Plasmonic Modes, Railing Chang, Huai Yi Xie, Ya-Chih Wang, Hai-Pang Chiang, P.T. Leung

Physics Faculty Publications and Presentations

Axion electrodynamics is applied to study the response of a plasmonic nanoshell with a core made of topological insulator (TI) materials. The electric polarizability of such a system is calculated in the long wavelength limit via the introduction of two scalar potentials satisfying the various appropriate boundary conditions. Our focus is on the topological magneto-electric effect (TME) as manifested in the coupled plasmonic resonances of the nanoshell. It is found that for a TI with broken time-reversal symmetry, such TME will lead to observable red-shifts in the coupled plasmonic modes, with more significant manifestation of such shifts for the bonding …

Comparing Hecke Coefficients Of Automorphic Representations, Liubomir Chiriac, Andrei Jorza

Mathematics and Statistics Faculty Publications and Presentations

We prove a number of unconditional statistical results of the Hecke coefficients for unitary cuspidal representations of over number fields. Using partial bounds on the size of the Hecke coefficients, instances of Langlands functoriality, and properties of Rankin-Selberg -functions, we obtain bounds on the set of places where linear combinations of Hecke coefficients are negative. Under a mild functoriality assumption we extend these methods to . As an application, we obtain a result related to a question of Serre about the occurrence of large Hecke eigenvalues of Maass forms. Furthermore, in the cases where the Ramanujan conjecture is satisfied, we …

Microplastic Concentrations In Two Oregon Bivalve Species: Spatial, Temporal, And Species Variability, Britta Baechler, Elise F. Granek, Matthew V. Hunter, Kathleen E. Conn

Environmental Science and Management Faculty Publications and Presentations

Microplastics are an ecological stressor with implications for ecosystem and human health when present in seafood. We quantified microplastic types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 Oregon coast, U.S.A. sites. Microplastics were present in organisms from all sites. On average, whole oysters and razor clams contained 10.95 ± 0.77 and 8.84 ± 0.45 microplastic pieces per individual, or 0.35 ± 0.04 pieces g⁻¹ tissue and 0.16 ± 0.02 pieces g⁻¹ tissue, respectively. Contamination was quantified but not subtracted. Over …

Alignment Of Theoretically Grounded Constructs For The Measurement Of Science And Chemistry Identity, Kathryn Nicole Hosbein, Jack Barbera

Chemistry Faculty Publications and Presentations

Identity has been theorized to aid in student persistence within STEM disciplines. In this study, science and chemistry identity were defined as being recognized as a science or chemistry person within the classroom. To generalize the effects that identity has on student persistence, a measurable construct must be defined, operationalized, and tested in multiple settings with different populations. This project addressed the first step in the process, defining the construct and grounding it in an established theoretical framework. This qualitative project utilized a previously described physics identity framework, with sub-constructs of performance/competence, recognition, and interest, as a starting point for …

Microplastic Occurrence And Effects In Commercially Harvested North American Finfish And Shellfish: Current Knowledge And Future Directions, Britta Baechler, Cheyenne Stienbarger, Dorothy Horn, Jincy Joseph, Allison Taylor, Elise F. Granek, Susanne Brander

Environmental Science and Management Faculty Publications and Presentations

Commercial fisheries yield essential foods, sustain cultural practices, and provide widespread employment around the globe. Commercially harvested species face a myriad of anthropogenic threats including degraded habitats, changing climate, overharvest, and pollution. Microplastics are pollutants of increasing concern, which are pervasive in the environment and can harbor or adsorb pollutants from surrounding waters. Aquatic organisms, including commercial species, encounter and ingest microplastics, but there is a paucity of data about those caught and cultured in North America. Additional research is needed to determine prevalence, physiological effects, and population-level implications of microplastics in commercial species from Canada, the United States, and …

Widespread Severe Wildfires Under Climate Change Lead To Increased Forest Homogeneity In Dry Mixed-Conifer Forests, Brooke Alyce Cassell, Robert M. Scheller, Melissa S. Lucash, Matthew Hurteau, E. Louise Loudermilk

Environmental Science and Management Faculty Publications and Presentations

Climate warming in the western United States is causing changes to the wildfire regime in mixed-conifer forests. Rising temperatures, longer fire seasons, increased drought, as well as fire suppression and changes in land use, have led to greater and more severe wildfire activity, all contributing to altered forest composition over the past century. To understand future interactions among climate, wildfire, and vegetation in a fire-prone landscape in the southern Blue Mountains of central Oregon, we used a spatially explicit forest landscape model, LANDIS-II, to simulate forest and fire dynamics under current management practices and two projected climate scenarios. The results …

Urban-Rural Surface Temperature Deviation And Intra-Urban Variations Contained By An Urban Growth Boundary, Kevan B. Moffett, Yasuyo Makido, Vivek Shandas

Urban Studies and Planning Faculty Publications and Presentations

The urban heat island (UHI) concept describes heat trapping that elevates urban temperatures relative to rural temperatures, at least in temperate/humid regions. In drylands, urban irrigation can instead produce an urban cool island (UCI) effect. However, the UHI/UCI characterization suffers from uncertainty in choosing representative urban/rural endmembers, an artificial dichotomy between UHIs and UCIs, and lack of consistent terminology for other patterns of thermal variation at nested scales. We use the case of a historically well-enforced urban growth boundary (UGB) around Portland (Oregon, USA): to explore the representativeness of the surface temperature UHI (SUHI) as derived from Moderate Resolution Imaging …

On The Equality Case Of The Ramanujan Conjecture For Hilbert Modular Forms, Liubomir Chiriac

Mathematics and Statistics Faculty Publications and Presentations

The generalized Ramanujan Conjecture for cuspidal unitary automorphic representations π on GL(2) asserts that |av(π)| ≤ 2. We prove that this inequality is strict if π is generated by a CM Hilbert modular form of parallel weight two and v is a finite place of degree one. Equivalently, the Satake parameters of πv are necessarily distinct. We also give examples where the equality case does occur for primes of degree two.

Remote Characterization Of Dominant Wavelengths From Surface Folding On Lava Flows Using Lidar And Discrete Fourier Transform Analyses, Nicholas Deardorff, Adam M. Booth, Katharine Cashman

Geology Faculty Publications and Presentations

Surface folding is common in lava flows of all compositions and is believed to be due to changes in viscosity and flow velocity between the cooling crust and the more fluid flow interior. However, our understanding of the relationship between surface folding and flow rheology is incomplete. In this study we analyze digital terrain models of eight lava flows ranging in composition from basaltic andesite to rhyolite using a discrete Fourier transform analysis to quantitatively determine dominant surface fold wavelengths. Our discrete Fourier transform analyses show that each lava flow has multiple fold generations and that dominant wavelengths are more …

Traditional Knowledge Of Fire Use By The Confederated Tribes Of Warm Springs In The Eastside Cascades Of Oregon, Michelle M. Steen-Adams, Susan Charnley, Rebecca Mclain, Mark D. O. Adams, Kendra L. Wendel

Institute for Sustainable Solutions Publications and Presentations

We examined traditional knowledge of fire use by the Ichishikin (Sahaptin), Kitsht Wasco (Wasco), and Numu (Northern Paiute) peoples (now Confederated Tribes of Warm Springs, CTWS) in the eastside Cascades of Oregon to generate insights for restoring conifer forest landscapes and enhancing culturally-valued resources. We examined qualitative and geospatial data derived from oral history interviews, participatory GIS focus groups, archival records, and historical forest surveys to characterize cultural fire regimes (CFRs) –an element of historical fire regimes– of moist mixed conifer (MMC), dry mixed conifer (DMC), and shrub-grassland (SG) zones. Our ethnohistorical evidence indicated a pronounced cultural fire regime in …

Diffusion And Consensus On Weakly Connected Directed Graphs, J. J. P. Veerman, Ewan Kummel

Mathematics and Statistics Faculty Publications and Presentations

Let G be a weakly connected directed graph with asymmetric graph Laplacian L. Consensus and diffusion are dual dynamical processes defined on G by x˙=−Lx for consensus and p˙=−pL for diffusion. We consider both these processes as well their discrete time analogues. We define a basis of row vectors {γ¯i}ki=1 of the left null-space of L and a basis of column vectors {γi}ki=1 of the right null-space of L in terms of the partition of G into strongly connected components. This allows for complete characterization of the asymptotic behavior of both diffusion and consensus --- discrete and continuous --- in …

Iodane-Guided C-H Cleavage To Synthesize Densely Functionalized Arenes, Aleksandra Nilova, Paul A. Sibbald, Edward J. Valente, Gisela Gonzalez-Monteil, H. Camille Richardson, Kevin S. Brown, Paul Cheong, David Stuart

Chemistry Faculty Publications and Presentations

We describe a strategy for the iodane-guided functionalization of sterically congested C-H bonds, which is distinct from electronic, steric or proximity guided C-H functionalization methods. Readily accessible aryl(Mes)iodonium salts serve as the starting materials in these reactions and produce complex 1,2,3,4-substituted arenes via aryne intermediates. This approach is especially powerful when coupled with the innate C-H functionalization reactivity of simple arenes, to replace two C-H bonds with two C-C or C-heteroatom bonds while over-riding steric effects that typically inhibit such reactions. DFT stud-ies reveal a contribution of inductive, resonance, and steric effects on the regioselectivity of C-H cleavage and aryne …

Using A Local Positioning System To Track 2d Motion, Paul R. Destefano, Cora Siebert, Ralf Widenhorn

Physics Faculty Publications and Presentations

Tracking the motion of an object in 2D as a demonstration in a physics classroom or as a laboratory activity is difficult to accomplish in real time with traditional equipment used by educators. A local positioning system (LPS), like the Pozyx Creator series LPS,1 has a potentially wide range of educational applications for introductory physics courses. In a previous article2 we reported using this product to track one-dimensional motion, pressure, rotation, and magnetic field data, but here we discuss how such systems can provide location information (to within approximately ±10 cm) in one, two, and potentially three dimensions both indoors …

Adapting Realtime Physics For Distance Learning With The Iolab, Erik Bodegom, Erik Jensen, David Sokoloff

Physics Faculty Publications and Presentations

The IOLab is a versatile and inexpensive data acquisition device in a cart that can roll on its three wheels. It has numerous sensors for a variety of physical quantities. We adapted RealTime Physics, Module 1: Mechanics active learning labs for use with the IOLab. We tested these labs both on campus and with distance learners at Portland State University and Chemeketa Community College for three years, consistently obtaining significant conceptual learning gains on the Force and Motion Conceptual Evaluation (FMCE). Student attitudes towards the labs, the device, and distance learning—as measured by post-course evaluations—were generally very positive.

Social Vulnerability To Large Wildfires In The Western Usa, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Michelle A. Day

Environmental Science and Management Faculty Publications and Presentations

Federal land managers in the US can be informed with quantitative assessments of the social conditions of the populations affected by wildfires originating on their administered lands in order to incorporate and adapt their management strategy to achieve a more targeted prioritization of community wildfire protection investments. In addition, these assessments are valuable to socially vulnerable communities for quantifying their exposure to wildfires originating on adjacent land tenures. We assessed fire transmission patterns using fire behavior simulations to understand spatial variations across three diverse study areas (North-central Washington; Central California; and Northern New Mexico) to understand how different land tenures …

Convective Instabilities Derived From Dissipation Of Chemical Energy, Reuben H. Simoyi, Matthew W. Eskew

Chemistry Faculty Publications and Presentations

Oxidation reactions of a series of organosulfur compounds by chlorite are excitable, autocatalytic, and exothermic and generate a lateral instability upon being triggered by the autocatalyst. This article reports on the convective instabilities derived from the reaction of chlorite and thiourea in a Hele-Shaw cell. Reagent concentrations used for the development of convective instabilities delivered a temperature jump at the wave front of 2.1 K. The reaction zone was 2 mm and due to normal cooling after the wave front, this induced a spike rather than the standard well-studied front propagation. Localized spatiotemporal patterns develop around the wave front. This …

Modeling The Defects That Exists In Crystalline Structures, Kiet A. Tran

REU Final Reports

This paper focuses on modeling defects in crystalline materials in one-dimension using field dislocation mechanics (FDM). Predicting plastic deformation in crystalline materials on a microscopic scale allows for the understanding of the mechanical behavior of micron-sized components. Following Das et al (2013), a one dimensional reduction of the FDM model is implemented using Discontinuous Galerkin method and the results are compared with those obtained from the finite difference implementation. Test cases with different initial conditions on the position and distribution of screw dislocations are considered.

Do Corporate Owned Adaptive Learning Platforms Perpetuate Banking Style Learning? Integrating Technology For Activism Into Transformational Sustainability Education, Tina M. Garner

Leadership for Sustainability Education Comprehensive Papers

We live in a world that tends to be controlled by corporations. The public school system should be wary of the problems that corporate control has on education. Even though public schools should not have corporate influence, the fact remains that they do, and this perpetuates Freire's banking style learning. Through time, the corporate influence in education was through educational materials such as book sales. Since the decline of the use of books and the growth of the use of technologies, corporations have followed suit through the sales of Adaptive Learning Platforms. Through leveraging the technology which students enjoy using, …

Assessing Affective Differences Between A Virtual General Chemistry Experiment And A Similar Hands-On Experiment, Cory Hensen, Jack Barbera

Chemistry Faculty Publications and Presentations

To date, few general chemistry laboratory studies have included affective measures despite calls for more research on aspects of this domain. This shortage of studies may be partially due to the scarcity of affective measures that have been designed for, or tested in, the college laboratory setting. To provide measures for use in this environment, several existing affective scales were adapted for this new context. Before data from the scales were utilized to study the environment, evidence was provided for the validity and reliability of the data generated from them. Once sufficient evidence was provided, it was possible to determine …

Discretization Of The Hellinger-Reissner Variational Form Of Linear Elasticity Equations, Kevin A. Sweet

REU Final Reports

This paper addresses the derivation of the Hellinger-Reissner Variational Form from the strong form of a system of linear elasticity equations that are used in relation to geological phenomena. The problem is discretized using finite element discretization. This allowed the creation of a program that was used to run tests on various domains. The resultant displacement vectors for tested domains are shown at the end of the paper.

Wind Turbine Audibility And Noise Annoyance In A National U.S. Survey: Individual Perception And Influencing Factors, Ryan Haac, Kenneth Kaliski, Matthew Landis, Ben Hoen, Joseph Rand, Jeremy Firestone, Deborah Elliott, Multiple Additional Authors

Regional Research Institute for Human Services

With results from a nationwide survey sponsored by the U.S. Department of Energy, factors that affect outdoor audibility and noise annoyance of wind turbines were evaluated. Wind turbine and summer daytime median background sound levels were estimated for 1043 respondents. Wind turbine sound level was the most robust predictor of audibility yet only a weak, albeit significant, predictor of noise annoyance. For each 1 dB increase in wind turbine sound level (L1h-max), the odds of hearing a wind turbine on one's property increased by 31% [odds ratio (OR): 1.31; 95% CI (confidence interval): 1.25–1.38] and the odds of moving to …

Toxic Chemical Governance Failure In The United States: Key Lessons And Paths Forward, Ariana M. Chiapella, Zbigniew Grabowski, Mary Ann Rozance, Ashlie D. Denton, Manar A. Alattar, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Over 40 years of regulations in the United States have failed to protect human and environmental health. We contend that these failures result from the flawed governance over the continued production, use, and disposal of toxic chemicals. To address this failure, we need to identify the broader social, political, and technological processes producing, knowing, and regulating toxic chemicals, collectively referred to as toxic chemical governance. To do so, we create a conceptual framework covering five key domains of governance: knowledge production, policy design, monitoring and enforcement, evaluation, and adjudication. Within each domain, social actors of varying power negotiate what constitutes …

Trefftz Finite Elements On Curvilinear Polygons, Akash Anand, Jeffrey S. Ovall, Samuel E. Reynolds, Steffen Weisser

Mathematics and Statistics Faculty Publications and Presentations

We present a Trefftz-type finite element method on meshes consisting of curvilinear polygons. Local basis functions are computed using integral equation techniques that allow for the efficient and accurate evaluation of quantities needed in the formation of local stiffness matrices. To define our local finite element spaces in the presence of curved edges, we must also properly define what it means for a function defined on a curved edge to be "polynomial" of a given degree on that edge. We consider two natural choices, before settling on the one that yields the inclusion of complete polynomial spaces in our local …

The Fourier Spectrum Of A Singing Wine Glass, Reuben Leatherman, Justin Charles Dunlap, Ralf Widenhorn

Physics Faculty Publications and Presentations

The phenomenon of the singing wineglass is familiar to many. Most people have run a finger along the rim of a wine glass with the right speed and pressure to get it to whistle a tone or perhaps heard a glass harmonica being played. However, have you ever noticed and wondered why the vibrations caused by a finger on a glass produce a pulsating sound, rather than a steady, constant-amplitude vibration? Further exploration reveals that the sound and pulsations of a wine glass vary depending on the way the wine glass is stimulated. In this paper, we investigate and model …

Family Math Night: Increasing Engagement In University Mathematics Courses For Prospective Teachers, Eva Thanheiser

Mathematics and Statistics Faculty Publications and Presentations

Prospective elementary school teachers (PSTs) often do not perceive mathematics activities as fun or engaging and perceive the mathematics tasks in their university content courses as inauthentic and irrelevant. Both these points were addressed by connecting the university classroom tasks to the K–5 environment via a Family Math Night (FMN). Survey results from 23 PSTs showed that PSTs were excited about the authenticity of the tasks, learned about children’s mathematical thinking, and reconceptualized mathematics learning as potentially enjoyable. In combination, these results may lead to PSTs’ increased engagement in the mathematics content course and, thus, result in their increased mathematics …

Psu Green Building Internship Final Report, 2019: Karl Miller Center Post-Occupancy Study, Everett Stilley, Junyoung Lee

Campus Sustainability Office Publications, Reports and Presentations

This study examined the effectiveness of the passive cooling strategies in the Karl Miller Center (KMC) at Portland State University. Due to the warm temperatures reached in Portland during the summer months and the absence of a mechanical cooling system on the Pavilion side of the KMC, classrooms can exceed thermal comfort preferences on a number of occasions. Previous studies have recommended taking certain classrooms “offline” after 12pm in the summer, where they are only available for morning classes. This study aimed to update the classroom prioritization as well as analyze the employed cooling strategies and begin a long term …

Data From: Microplastic Concentrations In Two Oregon Bivalve Species: Spatial, Temporal, And Species Variability, Britta Baechler, Elise F. Granek, Matthew V. Hunter, Kathleen E. Conn

Environmental Science and Management Datasets

Microplastics are an ecological stressor with implications for ecosystem and human health when present in seafood. We quantified microplastic types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 Oregon coast, U.S.A. sites. Organisms were chemically digested and visually analyzed for microplastics, and material type was determined using Fourier Transform Infrared Spectroscopy. Microplastics were present in organisms from all sites. On average, whole oysters and razor clams contained 10.95 ± 0.77 and 8.84 ± 0.45 microplastic pieces per individual, or 0.35 ± 0.04 and …

Rare, Threatened And Endangered Species Of Oregon (2019), Jimmy Kagan, Sue Vrilakas, Eleanor P. Gaines, Lindsey K. Wise, Michael Russell, Cayla Sigrah

Institute for Natural Resources Publications

The Oregon Biodiversity Information Center (ORBIC) is part of the Institute for Natural Resources (INR) located at Portland State University (PSU). ORBIC maintains extensive databases of Oregon biodiversity, concentrating on rare and endangered plants, animals and ecosystems. Since its creation in 1979 as the Oregon Natural Heritage Program, ORBIC has been part of the Natural Heritage network. ORBIC is a constituent member of NatureServe, a non-profit organization with a mission to provide the scientific basis for effective conservation action. NatureServe and Oregon manage data using standards and protocols used across the U.S., Canada, and much of Latin America.

ORBIC has …

Multiwavelength Digital Holographic Imaging And Phase Unwrapping Of Protozoa Using Custom Fiji Plug-Ins, David Cohoe, Iulia Hanczarek, J. Kent Wallace, Jay Nadeau

Physics Faculty Publications and Presentations

Multiwavelength digital holographic microscopy (DHM) has been used to improve phase reconstructions of digital holograms by reducing 2p phase ambiguities. However, most samples used as test images have been solid or adhered to a surface, making it easy to determine focal planes and correct for chromatic aberration. In this study we apply 3-wavelength off-axis DHM to swimming protozoa containing distinct spectral features such as chlorophyll and carotenoids. We reconstruct the holograms into amplitude and phase images using the angular spectrum method. Methods for noise subtraction, chromatic aberration correction, and image registration are presented for both amplitude and phase. Approaches to …