Digital Commons Network^™

Anthropogenic Effects On The Fouling Community: Impacts Of Biological Invasions And Anthropogenic Structures On Community Structure, Whitney Elizabeth Mcclees

Dissertations and Theses

Coastal anthropogenic infrastructure has significantly modified nearshore environments. Because these structures often have a strong association with shipping as would be found in ports and harbors, they have been identified as invasion hotspots. Due to propagule pressure from shipping and recreational boating and suitable uncolonized substrate that provides a refuge from native predators, a greater number of non-native species have been found on these structures compared to nearby natural substrate. The mechanisms that limit the spread of non-native species from anthropogenic structures to natural substrate have been explored for several taxa at a species-specific level, but less so from an …

The Discovery And Development Of Metal-Free Arylation Reactions With Unsymmetrical Diaryliodonium Salts, Sunil Kumar Sundalam

Dissertations and Theses

Functionalizing arenes and heteroarenes has been an active area of research since the 19th century, due to the presence of these molecular structures in many industrially important sectors. A tremendous amount of research has been published in achieving these chemical transformations using stoichiometric reagents and transition metal-catalyzed reactions. However, challenges still remain. An alternative and comparable methodology to metal-catalyzed reactions to overcome the drawbacks will advance this particular area of research is desirable.

Hypervalent iodine compounds offer a promising approach to metal-free arylation reactions. These mild, air and moisture stable compounds have showed significant success as non-toxic and metal-free reagents …

Trade-Offs: The Production Of Sustainability In Households, Kirstin Marie Elizabeth Munro

Dissertations and Theses

Over the past half-century, environmental problems have become increasingly serious and seemingly intractable, and a careless, clueless, or contemptuous consumer is often portrayed as the root cause of this environmental decline. This study takes a different approach to evaluating the demand for resources by households, assessing possible pro-environmental paths forward through a study of highly ecologically-conscious households. By modeling "green" households as producers of sustainability rather than consumers of environmental products, the sustainability work that takes place in households is brought into focus. An investigation of household sustainability production makes possible the evaluation of the trade-offs inherent in these pro-environmental …

A Finite Difference Method For Off-Fault Plasticity Throughout The Earthquake Cycle, Brittany A. Erickson, Eric M. Dunham, Arash Khosravifar

Mathematics and Statistics Faculty Publications and Presentations

We have developed an efficient computational framework for simulating multiple earthquake cycles with off-fault plasticity. The method is developed for the classical antiplane problem of a vertical strike-slip fault governed by rate-and-state friction, with inertial effects captured through the radiationdamping approximation. Both rate-independent plasticity and viscoplasticity are considered, where stresses are constrained by a Drucker-Prager yield condition. The off-fault volume is discretized using finite differences and tectonic loading is imposed by displacing the remote side boundaries at a constant rate. Time-stepping combines an adaptive Runge-Kutta method with an incremental solution process which makes use of an elastoplastic tangent stiffness tensor …

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

Geology Faculty Publications and Presentations

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, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km². Results show that 5036 G&PS (672 km², 14 km³) populate eight states, of which about 1276 (554 km^2, 12 km³) are glaciers. …

A Functional Subnetwork Approach To Designing Synthetic Nervous Systems That Control Legged Robot Locomotion, Nicholas Szczecinski, Alexander J. Hunt, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

A dynamical model of an animal’s nervous system, or synthetic nervous system (SNS), is a potentially transformational control method. Due to increasingly detailed data on the connectivity and dynamics of both mammalian and insect nervous systems, controlling a legged robot with an SNS is largely a problem of parameter tuning. Our approach to this problem is to design functional subnetworks that perform specific operations, and then assemble them into larger models of the nervous system. In this paper, we present networks that perform addition, subtraction, multiplication, division, differentiation, and integration of incoming signals. Parameters are set within each subnetwork to …

Interactions Among Fuel Management, Species Composition, Bark Beetles, And Climate Change And The Potential Effects On Forests Of The Lake Tahoe Basin, Robert M. Scheller, Alec M. Kretchun, E. Louise Loudermilk, Matthew D. Hurteau, Peter J. Weisberg, Carl Skinner

Environmental Science and Management Faculty Publications and Presentations

Climate-driven increases in wildfires, drought conditions, and insect outbreaks are critical threats to forest carbon stores. In particular, bark beetles are important disturbance agents although their long-term interactions with future climate change are poorly understood. Droughts and the associated moisture deficit contribute to the onset of bark beetle outbreaks although outbreak extent and severity is dependent upon the density of host trees, wildfire, and forest management. Our objective was to estimate the effects of climate change and bark beetle outbreaks on ecosystem carbon dynamics over the next century in a western US forest. Specifically, we hypothesized that (a) bark beetle …

Aryl Transfer Selectivity In Metal-Free Reactions Of Unsymmetrical Diaryliodonium Salts, David Stuart

Chemistry Faculty Publications and Presentations

Aromatic rings are found in a wide variety of products, including pharmaceuticals, agrochemicals, and functional materials. Diaryliodonium salts are novel reagents used to transfer aryl groups under both metal-free and metal-catalyzed reactions and thereby synthesize arene-containing compounds. This review focuses on recent studies in selective aryl transfer reactions from unsymmetrical diaryliodonium salts under metal-free conditions. Reactions reported from 2008 to 2017, which represents a period of significant growth in diaryliodonium salt chemistry, are presented and organized by the type of reactive intermediate formed in the reaction. Specifically, reactions involving λ³-iodane, λ³-iodane radical anions, aryl radicals, and …

Archival Water-Level Measurements: Recovering Historical Data To Help Design For The Future, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An obvious approach to improving the statistical robustness of risk assessments is to increase the number, time span, and quality of available water-level data sets, and to assess trends and non-stationarity. In this report we discuss efforts to recover, digitize, and analyze hundreds of station-years of lost-and-forgotten tide data and other water-level measurements that extend back to the early 19th century. To date, more than 6,500 station-years of previously lost …

Low-Dose And In-Painting Methods For (Near) Atomic Resolution Stem Imaging Of Metal Organic Frameworks (Mofs), B. Layla Mehdi, A. J. Stevens, Peter Moeck, Alice Dohnalkova, A. Vjunov, John L. Fulton, Donald M. Camaioni, Omar K. Farha, Joseph T. Hupp, Bruce C. Gates, Johannes A. Lercher, Nigel D. Browning

Physics Faculty Publications and Presentations

Metal-organic Frameworks (MOFs) are a group of crystalline and highly porous materials consisting of inorganic metal ions/clusters (nodes) that are coordinated by organic linkers. The ability to create a wide range of porous structures, where the pore size can be easily changed in size and shape offers the potential for many applications in gas storage/separation and catalysis. The presence of the organic linkers or “struts” in the sample creates challenges for high resolution microscopy as the sample itself is very sensitive to beam damage. A key challenge for understanding the structures of MOFs and how the applications can be modified …

Knowing Nature In The City: Comparative Analysis Of Knowledge Systems Challenges Along The 'Eco-Techno' Spectrum Of Green Infrastructure In Portland & Baltimore, Annie Marissa Matsler

Dissertations and Theses

Green infrastructure development is desired in many municipalities because of its potential to address pressing environmental and social issues. However, despite technical optimism, institutional challenges create significant barriers to effective green infrastructure design, implementation, and maintenance. Institutional challenges stem from the disparate scales and facility types that make up the concept of green infrastructure, which span from large-scale natural areas to small engineered bioswales. Across these disparate facilities 1) different performance metrics are used, 2) different institutions have jurisdiction, and, 3) facility types are differentially classified as assets, producing epistemological and ontological variegation across the spectrum of green infrastructure that …

A Study Of Diverse, Inquiry-Based Science Education In Portland, Oregon, Alivia R. Degagne

University Honors Theses

As a result of the imbalance of success among racially and ethnically diverse students within STEM education, science, technology, engineering, and mathematics education is being recontextualized. Scholars and educators alike are finding the benefit in supporting inquiry based methods within the scientific curriculum because they increase a student’s science conceptualization. Three public elementary schools who lead in science education in Portland are analyzed and compared to two public elementary schools who do not have a specific focus on STEM. The comparison is created to determine the impact of the STEM programs being implemented are particularly beneficial to the diverse student …

Properties Of Carbon Nanotubes: Defects, Adsorbates, And Gas Sensing, Micah C. Eastman

Dissertations and Theses

Carbon nanotubes and graphene have been a trending research topic in the past decade. These graphitic compounds exhibit numerous advantageous properties (electronic, mechanical, thermal, optical, etc) which industry and researchers alike are excited to take advantage of. Beyond the challenges of yield and controlled growth, there are a number of standing questions which govern some of the more fundamental characteristics of these materials: What role do lattice defects play in the adsorption of gas molecules on the surface of carbon nanotubes? How are the electronic states of the carbon nanotubes influenced by these adsorbed molecules? And how can we develop …

Using The Task Analysis Process With Teachers To Uncover Language Demands Within An Eight-Week Ngss Summer Course, Leah Plack

Dissertations and Theses

The state of Oregon has adopted the Next Generation Science Standards as well as the English Language Proficiency standards, both of which affect elementary school teachers. These standards adoptions challenge teachers and professional developers to rethink how they approach science conceptual understanding and language acquisition. The Math Science Partnership K-6 Instructional Specialist Grant made the decision to incorporate a Task Analysis process, which asks the participant to analyze the demands of a content-based task in the domains of content knowledge, analytical skills and language, into six eight-week summer courses focused on the Next Generation Science Standards. A pre and post-assessment …

Combat Experiences, Iso-Strain, And Sleep Quality Affect Symptoms Of Posttraumatic Stress Among Working Post-9/11 Veterans, Gilbert Patrick Brady Jr.

Dissertations and Theses

Despite the growing need, prior research on how the civilian work domain may affect posttraumatic stress is scarce. Moreover, few if any studies have investigated how perceptions of one's job and insomnia may shape traumatic stress symptoms, post-combat. Presently, about 4 million Americans have served in the "Global War on Terrorism," including nearly 1 million reservists. By contrast, 8.7 million Americans served in the Vietnam War: over twice the number of U.S. military personnel who have fought since 9/11. Surprisingly, combat experiences alone do not explain the majority of posttraumatic stress disorder cases, even after multiple deployments, suggesting the presence …

Stereotype Threat And Effects Of Students' Perception Of Their Math Teacher's Fairness On Their Math Self-Efficacy, Alexis Jocelyn Devigal

Dissertations and Theses

Gender inequalities perpetuated by educational and occupational segregation may be exacerbated in part by socialization processes that occur in the years leading up to when high school students typically begin considering postsecondary options. Students’ feelings of self-efficacy in certain subjects can be an important factor that informs their decisions to pursue coursework and programs. This study used stereotype theory to understand how students' perceptions of their 9th grade math teacher's fairness affected their 11th grade math efficacy and how this relationship was moderated by the gender of the student and their math teacher. Using the High School Longitudinal Study of …

Creating An Open Textbook Publishing Program: Inside Pdxopen, Karen Bjork

Library Faculty and Staff Publications and Presentations

A look inside Portland State University Libary's open textbook publishing initiative, PDXOpen. The presentation focuses on recruiting authors, author selection and lessons learned.

The Littlefield Rhyolite, Eastern Oregon: Distinct Flow Units And Their Constraints On Age And Storage Sites Of Grande Ronde Basalt Magmas, Brian Mcculloch Webb

Dissertations and Theses

The Littlefield Rhyolite consists of widespread, high-temperature, hotspot-related rhyolitic lavas that erupted in eastern Oregon contemporaneous to late-stage Grande Ronde Basalt lavas. The estimated total volume of erupted rhyolites is ~100 km³ covering ~850 km².

The focus of this study has been to investigate the stratigraphy and petrology of the Littlefield Rhyolite and whether field and geochemical relationships exist to help constrain the timing and storage sites of Grande Ronde Basalt magmas. Although often indistinguishable in the field, our data reveal that the Littlefield Rhyolite consists of two geochemically distinct rhyolite flow packages that are designated here …

High-Resolution Elevation Mapping Of The Mcmurdo Dry Valleys, Antarctica, And Surrounding Regions, Andrew G. Fountain, Juan C. Fernandez-Diaz, Maciej K. Obryk, Joseph Levy, Michael N. Gooseff, David J. Van Horn, Paul Morin, Ramesh Shrestha

Geology Faculty Publications and Presentations

We present detailed surface elevation measurements for the McMurdo Dry Valleys, Antarctica derived from aerial lidar surveys flown in the austral summer of 2014–2015 as part of an effort to understand geomorphic changes over the past decade. Lidar return density varied from 2 to > 10 returns m−2with an average of about 5 returns m−2. Vertical and horizontal accuracies are estimated to be 7 and 3 cm, respectively. In addition to our intended targets, other ad hoc regions were also surveyed including the Pegasus flight facility and two regions on Ross Island, McMurdo Station, Scott Base (and surroundings), and the coastal …

Assessing The Potential Of Land Use Modification To Mitigate Ambient No2 And Its Consequences For Respiratory Health, Meenakshi Rao, Linda A. George, Vivek Shandas, Todd N. Rosenstiel

Urban Studies and Planning Faculty Publications and Presentations

Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO₂ is modeled based on spatially dense summer and winter NO₂ observations in Portland-Hillsboro-Vancouver (USA), and the spatial variation of NO₂ with LULC investigated using random forest, an ensemble data learning technique. The NO₂ random forest model, together with BenMAP, is further used to develop a better understanding of the relationship among LULC, ambient NO₂ and respiratory health. The impact of land use modifications on ambient NO₂, …

Dynamically Distinguishing Polynomials, Andrew Bridy, Derek Garton

Mathematics and Statistics Faculty Publications and Presentations

A polynomial with integer coefficients yields a family of dynamical systems indexed by primes as follows: For any prime p, reduce its coefficients mod p and consider its action on the field FpFp. We say a subset of Z[x]Z[x] is dynamically distinguishable mod p if the associated mod pdynamical systems are pairwise non-isomorphic. For any k,M∈Z>1k,M∈Z>1, we prove that there are infinitely many sets of integers MM of size M such that {xk+m∣m∈M}{xk+m∣m∈M} is dynamically distinguishable mod p for most p (in the sense of natural density). Our proof uses the Galois theory of dynatomic polynomials largely developed …

Impact Analysis Of Increased Dispatchable Resources On A Utility Feeder In Opendss, Crystal Eppinger

Dissertations and Theses

Oregon utilities are replacing their portfolios of traditional fossil fuel generation with renewable generating sources. Stepping away from carbon-producing energy will leave a deficit of on-demand power, resulting in decreased reliability. To overcome these technical challenges, utilities must maximize the use of their present dispatchable resources. One such resource is the Portland General Electric (PGE) Dispatchable Standby Generation Program (DSG), which is an aggregated 105 MWs of distributed generation (DG). These resources are brought on-line when there is a critical need for power. Resources are added to the program if a transfer trip scheme is in place or a modeling …

A Statistical Investigation Of Lower Columbia River Water Temperature, 1915-2003, Corina Christina Mae Overman

Civil and Environmental Engineering Undergraduate Honors Theses

The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (T_w) to survive. In recent years, high summer T_w in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased T_w include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of T_w based on air temperature (T_a) and Q were developed to examine the change in T_w over time. The data was …

Green Leasing Program Design For Psu, Emily Quinton

Campus Sustainability Office Publications, Reports and Presentations

Portland State University (PSU) serves as a Landlord to over 60 third-party tenants, including retail, food service, office, food cart, and other tenant types. To encourage and standardize the adoption and practice of sustainability behaviors among these tenants, PSU hired a Green Leasing Intern during the summer of 2017. The intern, graduate student Emily Quinton, managed by members of the PSU Planning, Construction & Real Estate (PCRE) team, was tasked with researching best practices, drafting green leasing language, and developing tenant engagement and incentive-based approaches to implementation. This report serves as the culminating deliverable for that internship. Additional internship documentation …

What Do We Know About Location Affordability In U.S. Shrinking Cities?, Joanna Ganning, Jenna Rosie Tighe

TREC Final Reports

In late 2013, the Department of Housing and Urban Development (HUD) launched the Location Affordability Index (LAI) portal. Their dataset uses models to estimate typical amount households spend on housing and transportation at the block group level, and calculates “H + T Affordability,” the percent of household income spent on these items. In our previous research, we analyzed 81 shrinking cities to determine how location affordability differs across various neighborhoods. Our results suggest that households in declining neighborhoods, as compared to stable or redeveloping neighborhoods, face the greatest H + T affordability challenges in shrinking cities. Furthermore, in declining neighborhoods, …

Psu Green Building Summer Internship Final Report, 2017: Interior Environmental And Indoor Air Quality Assessments Of Workspaces For Future Maintenance Of Parkmill’S Constant Air Volume (Cav) Hvac System, Bassam Alduhaim, Sofia Chavez Cruz

Campus Sustainability Office Publications, Reports and Presentations

Parkmill’s Design, Construction, and Mechanical Systems

The Parkmill building is located on the lower south section of Portland State University’s (PSU) urban campus between SW Park Avenue and SW Mill Street.The lot space, originally selected for the design proposal in 1956, was located between two buildings including the acquired Parkway Manor (currently designated as PSU housing) and former frame house-type buildings. The proposed building would supplement the evening and summer curriculum courses offered by the General Education Division (GED) in partnership with Portland State College and would become a vital resource for students in the Portland metropolitan area.

Origins Of Late- Pleistocene Coastal Dune Sheets, Magdalena And Guerrero Negro, From Continental Shelf Low-Stand Supply (70-20 Ka), Under Conditions Of Southeast Littoral- And Eolian-Sand Transport, In Baja California Sur, Mexico, Curt D. Peterson, Janette Murillo-Jiminez, Errol Stock, David M. Price, Steve W. Hostetler, David Percy

Geology Faculty Publications and Presentations

Shallow morpho-stratigraphic sections (n = 11) in each of two large coastal dune sheets including the Magdalena (7000 km²) and Guerrero Negro (8000 km²) dune sheets, from the Pacific Ocean side of Baja California Sur, Mexico, have been analyzed for dune deposit age. The shallow morpho-stratigraphic sections (∼2-10 m depth) include 11 new TL and 14C ages, and paleosol chronosequences, that differentiate cemented late Pleistocene dune deposits (20.7 ± 2.1 to 99.8 ± 9.4 ka) from uncemented Holocene dune deposits (0.7 ± 0.05 to at least 3.2 ± 0.3 ka). Large linear dune ridges (5-10 m …

Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor vegetation is often proposed as a passive approach for improving indoor air quality. While studies of outdoor environments indicate that vegetation can be an important sink of outdoor ozone, there is scant data in the literature concerning the dynamics of ozone uptake by indoor plants. This study determined ozone deposition velocities (v_d) for five common indoor plants (Peace Lily, Ficus, Calathia, Dieffenbachia, Golden Pothos). The transient v_d was calculated, using measured leaf areas for each plant, for exposures mimicking three diurnal cycles where ozone concentrations in chamber tests were elevated for 8 h followed by …

Ecological Homogenization Of Residential Macrosystems, Peter M. Groffman, Meghan Avolio, Jeannine Cavender-Bares, Neil D. Bettez, J. Morgan Grove, Sharon J. Hall, Sarah E. Hobbie, Kelli L. Larson, Susannah B. Lerman, Dexter H. Locke, James B. Heffernan, Jennifer L. Morse, Christopher Neill, Kristen C. Nelson, Jarlath O'Neil-Dunne, Diane E. Pataki, Colin Polsky, Rinku Roy Chowdhury, Tara Trammell

Environmental Science and Management Faculty Publications and Presentations

Similarities in planning, development and culture within urban areas may lead to the convergence of ecological processes on continental scales. Transdisciplinary, multi-scale research is now needed to understand and predict the impact of human-dominated landscapes on ecosystem structure and function

Feedforward Chemical Neural Network: An In Silico Chemical System That Learns Xor, Drew Blount, Peter Banda, Christof Teuscher, Darko Stefanovic

Electrical and Computer Engineering Faculty Publications and Presentations

Inspired by natural biochemicals that perform complex information processing within living cells, we design and simulate a chemically implemented feedforward neural network, which learns by a novel chemical-reaction-based analogue of backpropagation. Our network is implemented in a simulated chemical system, where individual neurons are separated from each other by semipermeable cell-like membranes. Our compartmentalized, modular design allows a variety of network topologies to be constructed from the same building blocks. This brings us towards general-purpose, adaptive learning in chemico: wet machine learning in an embodied dynamical system.