Digital Commons Network^™

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 …

Learn Model Of Career Trajectories: Application To The Stem Postdoctoral Scholar, Audrey J. Jaeger, Karen J. Haley, Tara D. Hudson

Educational Leadership and Policy Faculty Publications and Presentations

Postdoctoral scholars constitute a sizeable population within the academic workforce. Given the intended role of a postdoc position as a time of advanced training and professional development for a future academic career, particularly in science, technology, engineering, and math (STEM) fields, it is important to understand whether and how well the career-related needs of postdocs are being met. The purpose of this research was to understand STEM postdoctoral scholars’ career trajectories, with particular attention to the influences on their career-related decision making, by applying the Life Experiences and Role Negotiations (LEARN) model to qualitative data from interviews with 19 STEM …

Investigating The Accuracy Of One-Dimensional Volcanic Plume Models Using Laboratory Experiments And Field Data, James S. Mcneal, Graham Freedland, L. G. Mastin, Raúl Bayoán Cal, S. A. Solovitz

Mechanical and Materials Engineering Faculty Publications and Presentations

During volcanic eruptions, model predictions of plume height are limited by the accuracy of entrainment coefficients used in many plume models. Typically, two parameters are used, 𝛼 and 𝛽, which relate the entrained air speed to the jet speed in the axial and cross-flow directions, respectively. To improve estimates of these parameters, wind tunnel experiments have been conducted for a range of cross-wind velocities and turbulence conditions. Measurements are compared directly to computations from the 1-D plume model, Plumeria, in the near-field, bending region of the jet. Entrainment coefficients are determined through regression analysis, demonstrating optimal combinations of effective 𝛼 …

Congestion Pricing Efficiency And Equity, Michael Manville

PSU Transportation Seminars

Congestion pricing is effective, and efficient, but is it fair? One of the biggest concerns surrounding dynamic road charges is that they will harm low-income people. This seminar examines the equity implications of congestion charging, and argues that road pricing can satisfy the demands of both equity and efficiency.

A Computational Model For Recovery From Brain Injury, Wayne Wakeland

Systems Science Friday Noon Seminar Series

A computational simulation model calculates recovery trajectories following traumatic brain injury (TBI). Prior publications include a multi-scale framework for studying concussion and a systems-level causal loop diagram (CLD) and discussion of feedback processes. The scope of the computational model goes beyond concussion to include all severities of TBI. A set of first order ordinary differential equations and their associated parameters determines recovery trajectories. While highly speculative, the model serves to demonstrate the potential utility of computational models in this context. Much more research will be needed to create a properly supported research model that could be used for clinical trial …

The Impact Of Integrating Traditional Ecological Knowledge In Summer Camps On Middle School Students' Understanding Of The Nature Of Science, SapoóQ'Is WiíIt'es Ciarra Solina Greene

Dissertations and Theses

The Nature of Science (NOS) and traditional ecological knowledge (TEK) have commonalities in the knowledge bases: they are both ways of explaining the natural world; founded on a set of practices and the historical accumulation of knowledge; and part of the education is learning practices and developing knowledge of the concepts that are foundational to the disciplines. Throughout the United States, schools are attempting to strengthen students' understanding of NOS through various approaches, although few have adopted the integration of TEK into curriculum. This research assesses two summer camps for middle school students that are science focused, one with TEK …

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 …

Watershed Assessment Of Tryon Creek Of Oregon, Danielle Goodrich

Environmental Science and Management Professional Master's Project Reports

As the Tryon Creek Watershed Council (TCWC) continues to grow its organization, it is important to focus their efforts on lasting changes that most positively affect the watershed. The TCWC plays a community-appointed role as the binding element of agency and stakeholder partnerships throughout the Tryon Creek watershed by providing communication and cooperation. The watershed assessment aims to provide a compilation of existing data as well as an identification of data gaps and recommendations for future cooperative management of the watershed. Developing an understanding of the processes that shape the watershed can shed light on the status of measurable ecosystem …

Impact Of Titanium Dioxide Nanoparticles On Nutrient And Contaminant Reduction In Wastewater Treatment Wetlands, Madeline Hubbard

Civil and Environmental Engineering Master's Project Reports

Metallic nanoparticles are found in a variety of commercial products and industrial processes, and have become more common in the last few decades. As nanoparticles are toxic to biota and have the potential to spread other types of contamination, their increased use has become a concern. Research into the transport of nanoparticles in subsurface and surface waters shows a wide range in mobility, but that they are most likely to collect in systems with low linear velocities and high organic content. As a result, wetlands are the most vulnerable to nanoparticle contamination. Wetlands receiving and treating wastewater effluent have an …

Paints-R-Us Term Project, Tyler Campbell, Skye Gilbreth, Michael Oluwole, Elijah Raffo, Brad Unruh

Engineering and Technology Management Student Projects

This project will consider a linear product mix optimization problem for a fictional paint company, Paints-R-Us. Paints-R-Us is a wholesale paint manufacturer located in the Pacific Northwest. The Global Production Manager, Steve Brush, has been tasked with maximizing Paints-R-Us’s profit in the upcoming quarter. Steve Brush oversees the global production plan, and in collaboration with the production planners will develop a production plan which optimizes the profits that Paints-R-Us can create in the quarter accounting for the following criteria:

• Demand in the given quarter for each of the 5 paint types that Paints-R-Us produces • The warehousing storage capacity …

Fractals As Basis For Design And Critique, John Charles Driscoll

Dissertations and Theses

The design profession is responding to the complex systems represented by architecture and planning by increasingly incorporating the power of computer technology into the design process. This represents a paradigm shift, and requires that designers rise to the challenge of both embracing modern technologies to perform increasingly sophisticated tasks without compromising their objective to create meaningful and environmentally sensitive architecture. This dissertation investigated computer-based fractal tools applied within a traditional architectural charette towards a design process with the potential to address the complex issues architects and planners face today. We developed and presented an algorithm that draws heavily from fractal …

Audio Beat Detection With Application To Robot Drumming, Michael James Engstrom

Dissertations and Theses

This Drumming Robot thesis demonstrates the design of a robot which can play drums in rhythm to an external audio source. The audio source can be either a pre-recorded .wav file or a live sample .wav file from a microphone. The dominant beats-per-minute (BPM) of the audio would be extracted and the robot would drum in time to the BPM. A Fourier Analysis-based BPM detection algorithm, developed by Eric Scheirer (Tempo and beat analysis of acoustical musical signals)ⁱ was adopted and implemented. In contrast to other popular algorithms, the main advantage of Scheirer's algorithm is it has …

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 …

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 …

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 …

Fault Deformation At The Base Of And Within The Crescent Formation Along The Dosewallips River, Olympic Mountains Peninsula, Washington, Usa, Christine Meryl Maher

Dissertations and Theses

The Olympic Mountains, in the cost ranges of northwest Washington, expose a Cenozoic accretionary complex east of the Cascadia Subduction Zone. Accreted material consists of metasedimentary deposits thrust eastward beneath a basaltic terrane (i.e., the basaltic Crescent Formation and the basal Blue Mountain Unit [BMU] turbidite) along a major fault, the Hurricane Ridge Fault (HRF). Recent isotopic dating of zircons from the BMU indicate that it is about 8 my younger than the basalt, implying another major fault may exist east of the HRF, between the BMU and the Crescent Fm. Field observations, data, and samples for microstructural analysis were …

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 …

Connecting Local-Scale Heavy Precipitation To Large-Scale Meteorological Patterns Over Portland, Oregon Using Observations And Climate Models, Christina Marie Aragon

Dissertations and Theses

Precipitation timing and magnitude is essential to human, ecological, and economic systems. Climate change may be altering the character of precipitation locally to globally, thus it is vital that resource managers, practitioners, and decision makers understand the nature of this change. This thesis was conducted in partnership with the City of Portland Bureau of Environmental Services (BES), and the Portland Water Bureau (PWB) in order to support resiliency planning around precipitation and precipitation extremes.

This work has two primary phases, which are discussed in chapter 2 and 3 of this thesis. The first phase of this research entails characterization of …

Stormwater Treatment Effectiveness Of Established Bioretention Facilities In Portland, Oregon, Emma Rose Kohlsmith

Dissertations and Theses

Bioretention systems are commonly used to treat and detain stormwater runoff and help mitigate for many negative effects of urbanization. Despite the widespread use of bioretention systems, few field-based studies have assessed how these facilities affect water quality many years after installation. The goal of this project is to assess the pollution reduction effectiveness of lined bioretention facilities that have been in use and functioning for 4-8 years. To meet this objective, this project measured water quality characteristics of stormwater flowing into and out of seven facilities installed throughout Portland, Oregon during real storm events. Stormwater grab samples were taken …

Tracking Center Of Mass With Limited Inertial Measurement Units, Connor Nathaniel Morrow

Dissertations and Theses

Wearable motion tracking systems pose an opportunity to study and correct human balance and posture during movement. Currently, these observations are either being conducted in laboratories with the use of camera systems and markers placed on the body, or through the use of suits containing large numbers (15-20) of inertial measurement units. However, to aid with rehabilitation of individuals with impaired balance, there needs to be an option to collect these observations outside of clinics and without incurring much cost from the user. I have focused on three inertial measurement units, one placed on each shank and one placed on …

Seismic Source Characterization Of Faults In The Portland And Tualatin Basins And A Paleoseismic Study Of The Gales Creek Fault, Or, Alison Elizabeth Horst

Dissertations and Theses

Portland, OR lies within the tectonically active forearc of the Cascadia subduction zone. Several, potentially hazardous, northwest striking faults in and around the Portland Basin are classified as Quaternary active by the USGS, but little is known about their Holocene activity. Geologic and geodetic studies in the Pacific Northwest (PNW) document ongoing clockwise rotation of the region since at least 16 Ma. Models for crustal deformation in the PNW suggest northwest trending faults accommodate dextral shear inferred from increasing clockwise rotation rates west of Portland. I compiled structural information to improve the seismic source characterization of these faults, and using …

Correct-By-Construction Typechecking With Scope Graphs, Katherine Imhoff Casamento

Dissertations and Theses

Dependently-typed languages are well-known for the ability to enforce program invariants through type signatures, and previous work establishes the effectiveness of this style of program verification in the implementation of type-safe interpreters for a wide class of languages with a variety of interesting scoping semantics, offering an account of dynamic semantics. This thesis covers the complementary topic of static semantics, in the form of a pattern for constructing verified typechecking procedures in a dependently-typed setting. Implementations are given for simply-typed lambda calculus and a small procedural language as well as a module system with unrestricted cyclic module dependency semantics that …

Cooperating Teachers' Perceived Preparedness To Support Science Teacher Candidates For Culturally Sustaining Science Teaching, Keelan Purcell Lofaro

Dissertations and Theses

In the United States, many communities face challenges that require science, technology, engineering, and math (STEM) solutions. Those communities most affected by these challenges often lack opportunities in school to use their funds of knowledge as they develop STEM literacies that would equip them to address these challenges. With new national science standards and increasingly diverse student demographics in classrooms across the United States, teacher educators must utilize strategies that prepare science teacher candidates, who are predominantly White, with pedagogies that can support diverse learners in expanding their STEM literacies from their funds of knowledge. The problem of practice guiding …

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 …

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.

Historical Changes In Lower Columbia River And Estuary Floods: A Numerical Study, Lumas Helaire, Stefan Talke, David A. Jay, Andrew Mahedy

Civil and Environmental Engineering Faculty Publications and Presentations

Over the past 150 years, the Lower Columbia River Estuary controlling depth has approximately doubled, the majority of historical wetlands and floodplain have been reclaimed, numerous infrastructure projects have altered and confined flow pathways, and significant natural and anthropogenic changes to the discharge hydrograph have occurred. To investigate the effect of these changes on tides, river slope, and flood water levels, we construct and validate numerical models that simulate flow over late nineteenth‐century and present‐day bathymetry. The models are validated using archival (1853–1877) and modern tide measurements throughout the Lower Columbia River Estuary and river stage measurements from the tidal …

World Health Organization Cardiovascular Disease Risk Charts: Revised Models To Estimate Risk In 21 Global Regions, Stephen Kaptoge, Lisa Pennells, Dirk De Bacquer, Marie Therese Cooney, Maryam Kavousi, Gretchen Stevens, Leanne Margaret Riley, Stefan Savin, Taskeen Khan, Servet Altay, Carlos J. Crespo, Multiple Additional Authors

OHSU-PSU School of Public Health Faculty Publications and Presentations

Background: To help adapt cardiovascular disease risk prediction approaches to low-income and middle-income countries, WHO has convened an effort to develop, evaluate, and illustrate revised risk models. Here, we report the derivation, validation, and illustration of the revised WHO cardiovascular disease risk prediction charts that have been adapted to the circumstances of 21 global regions.

Methods: In this model revision initiative, we derived 10-year risk prediction models for fatal and non-fatal cardiovascular disease (ie, myocardial infarction and stroke) using individual participant data from the Emerging Risk Factors Collaboration. Models included information on age, smoking status, systolic blood pressure, history …

Hydrodynamic And Total Dissolved Solids Model Of The Tigris River Using Ce-Qual-W2, Muhanned D. Al-Murib, Scott Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The headwaters of the Tigris River basin in Iraq is controlled by Turkey due to a series of dams constructed over the last few decades. Since Total Dissolved Solids (TDS) in the Tigris River within Baghdad and downstream cities can reach 1000 mg/L exceeding both drinking water and irrigation guidelines, a hydrodynamic and water quality model, CE-QUAL-W2, of the river was developed to understand how changes in flow affect TDS downstream. A model of 880 km of the Tigris River from Mosul Dam to Kut Barrage including Tharthar Lake was constructed for 2009. Model development was challenging due to a …

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 …