Digital Commons Network^™

Annual And Seasonal Variation In Hydrologic Performance Of Ecoroofs Of Multiple Depths, Portland, Or, Ashley Michelle Baker

Dissertations and Theses

It is essential that cities adopt new approaches to stormwater management in the face of changing precipitation regime. In some locations, ecoroofs have been incorporated into city plans as a stormwater control measure, and thus their real-world performance under current conditions can assist with adequate planning. In this study rainfall retention data collected during a three year period, between 2014-2017, is analyzed for 75mm and 125mm ecoroof plots in Portland, Oregon, USA. There is no difference in annual rainfall retention performance between the shallower and deeper plots. However, the 36% mean annual retention of the ecoroof plots is a significant …

The Invasion Ecology Of Ivy (Hedera Spp.) In Portland's Forest Park, Eric Paul Butler

Dissertations and Theses

Invasive ivy (Hedera spp.) has extensive impacts on Pacific Northwest urban forests, many of which are not yet fully understood. In this study of Forest Park, Portland, Oregon, I evaluated several environmental variables obtained or derived from monitoring datasets at three spatial scales to determine the following: how ivy is spatially distributed; what factors are most correlated with ivy abundance; and how ivy abundance influences shrub community composition. I found that ivy is significantly clustered at all scales with multiple apparent epicenters along the park's urban periphery. Using NMDS ordination, I determined that ivy is a significant factor in …

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.

Numerical Algorithms For Solving Nonsmooth Optimization Problems And Applications To Image Reconstructions, Karina Rodriguez

REU Final Reports

In this project, we apply nonconvex optimization techniques to study the problems of image recovery and dictionary learning. The main focus is on reconstructing a digital image in which several pixels are lost and/or corrupted by Gaussian noise. We solve the problem using an optimization model involving a sparsity-inducing regularization represented as a difference of two convex functions. Then we apply different optimization techniques for minimizing differences of convex functions to tackle the research problem.

Upstream Predictors Of The Need For Developmental Education Among First-Year Community College Students, Mathew C. Uretsky, Stacey L. Shipe, Angela K. Henneberger

School of Social Work Faculty Publications and Presentations

Objective/Research Question. How do student- and school-level factors measured in the final year of high school contribute to the odds of a student being assessed to need remediation in Math during the students’ first community college enrollment? Methods. The present study draws on five years of linked secondary and post-secondary administrative records and includes the academic records for 18,814 students attending 228 high schools across 24 jurisdictions in Maryland. We used a series of multilevel models (MLM) to address the research question. Results. Using MLM, we identified both student and school-level factors, drawn from the final year of high school, …

The Impact Of Implementing Different Cordon Size Designs On Land Use Patterns In Portland, Or, Asia Spilotros

Dissertations and Theses

The purpose of this research dissertation is to compare the effects of using small, medium, and large cordon designs in road tolling on residential and commercial neighborhoods in Portland, Oregon. Changes in land use patterns are assessed by comparing the projected output of each cordon scenario to a "no toll" alternative in 2035. The performance of each cordon design is tested using two different prices ($1.65 and $8) and compared to a default scenario 25 years after the initial implementation in MetroScope's year 0, 2010. The following areas embedded within the cordon perimeter were considered in determining changes in land …

Modeling Surface Roughness As An Indicator Of Age And Landslide Susceptibility, And The Spatial Inventory Of Prehistoric Landslides: Green River Valley, Washington, Rebecca Naomi Garriss

Dissertations and Theses

Developing detailed landslide inventory maps of prehistoric landslides is essential to interpret the frequency and conditions under which slopes have failed. When coupled with age estimates, landslide inventories can yield better predictions for future slope failures, thereby improving hazard assessments and increasing chances for mitigation. Developing proxies for landslide age is an important area of research, but age dating prehistoric landslides can be challenging due to sparse datable organic material within landslide deposits, and to time or access constraints. In this thesis, surface roughness of the landslide deposit is used to construct a best-fit age-roughness model that quantitatively assigns age …

Non-Contact Distillation, Rawand Muzafar Rasheed

Dissertations and Theses

Leidenfrost phenomenon has been studied extensively for its role in applications ranging from nuclear reactor cooling, to metals manufacturing, combustion, and other fields. Herein, Leidenfrost phenomenon is pursued towards non-contact distillation processes with hopes of reducing or even eliminating contaminant fouling. In particular, the microgravity environment of a drop tower is exploited to demonstrate the facility with which droplets achieve and sustain the Leidenfrost state. Dynamic Leidenfrost impacts in microgravity are presented for impacts on hydrophilic and superhydrophobic planar substrates, macro-pillar arrays, confined passageways, and others. Nearly ideal elastic non-contact impacts and droplet oscillation modes are observed. Dynamic Leidenfrost impacts …

The Influence Of Neighborhood Landscape Characteristics On Native Bird Communities: Implications For Increasing Biodiversity In Our Yards, Michael E. Vermeulen

Dissertations and Theses

Avian communities, because of their potential high diversity, are ideal for studying the response to potential quantity of resources provided by local and regional habitat. Urban neighborhoods vary in types and magnitudes of anthropogenic stressors they experience, resulting in a continuum of anthropogenic disturbance, often referred to as a gradient of urbanization. The aim of this study was to investigate anthropogenic drivers of urban bird communities in three Portland, OR neighborhoods (Hillsdale, Lents, and Pearl). The three major questions of this study were: 1) What are the significant landscape traits that characterize the neighborhoods? 2) Is there evidence that the …

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, …

Water Quality Analysis Of Ecoroof Runoff In Portland, Pranoti P. Deshmukh

Civil and Environmental Engineering Master's Project Reports

Portland, Oregon is internationally recognized for its implementation of sustainable stormwater management technologies. Ecoroof is one of the sustainable solutions to reduce stormwater runoff which also provides multiple environmental benefits. However, very little is known about the impact of ecoroofs on water quality of roof runoff. Stormwater runoff carries a significant amount of pollutants, which, if it directly enters a stream or river, degrades water quality and severely harms aquatic life.

This study evaluates the trends in the long-term water quality data from ecoroofs and conventional roofs in the Portland area. Mann Kendall trend test was used to detect the …

Modeling Vertical Migration Of Cyanobacteria And Zooplankton, Corina Christina Mae Overman

Dissertations and Theses

Cyanobacteria, also known as blue-green algae, often cause harmful algal blooms and release toxic substances that can harm humans and other animals. Accurately modeling these phytoplankton is a step towards predicting, preventing, and controlling such blooms. Cyanobacteria and zooplankton species are known to migrate vertically in the water column on a daily cycle. Capturing this behavior is one aspect of correctly modeling their dynamics. Here, several models of cyanobacteria vertical movement were tested in proof-of-concept models before being applied to data from field studies. These models included both continuum and particle-tracking frameworks. Four continuum-framework models of cyanobacteria vertical migration were …

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 …

Evaluation Of Low And High Frequency Dynamic Response For Condition Assessment Of Reinforced Concrete Structures, Ali Hafiz

Dissertations and Theses

Concrete is widely used for civil infrastructure structures and they experience deterioration and degradation due to aging, increases in the traffic loads, harsher environmental conditions, use of deicing chemicals, etc. Therefore, evaluating the integrity of reinforced concrete structures has become of increasing interest for infrastructure owners and managers. A number of non-destructive testing (NDT) and structural health monitoring (SHM) methods have been developed in recent decades to aid in evaluating structures and provide input for asset management. One family of these methods uses the dynamic response of a structural member: stress waves (high frequency) and structural vibrations (low frequency). Both …

Re-Imagining Regulatory Approaches For Methane Emissions, Jongeun You

Hatfield Graduate Journal of Public Affairs

Recently, the U.S. Environmental Protection Agency (EPA) took a step-back in regulating the methane released during natural gas extraction. In June 2016, the EPA issued the first federal regulations on methane, estimating methane emissions would decrease by a total of 510,000 short tons in 2025, with a potential net benefit of $160 million. Yet, in October 2018, the EPA released a new proposal that weakened the 2016 methane rules, estimating methane emissions would increase by a total of 380,000 short tons in 2025, with a potential saving of $484 million. This paper explores the EPA’s drastic change between 2016 and …

A Network Approach To Complex Problems: Understanding Collaborative Governance In Watershed Management, Allison Daniel

Hatfield Graduate Journal of Public Affairs

The complexity of current environmental problems poses a challenge to the field of public management. With multiple stressors acting on the earth’s natural systems, the likelihood that complex environmental problems will persist is undeniable. Traditional approaches to such problems follow a top-down method, often useful for problem management within public policy; however, it proves too rigid when considering the complexity of environmental policy. Recent literature points to the use of collaboration and coordination in addressing complex problems, whereby stakeholders accumulate knowledge and resources across a variety of fields. One such method is network governance, identified as a problem-solving approach capable …

The Hidden Killer: Towards Regulating Railyard Diesel Particulate Matter Emissions In Oregon, Kevin Downing, Robert Mccullough, Eric Shierman

Hatfield Graduate Journal of Public Affairs

Diesel engines are the predominant choice when moving freight, particularly for the railroad industry. Compared to gasoline engines, diesel emits relatively few of the toxic compounds generally associated with internal combustion. However, diesel engines produce a disproportionate quantity of particulate aerosols. Airborne pollutants from locomotives and freight transferring equipment in railyards significantly impact the air quality of surrounding neighborhoods. We summarize the health impacts of diesel particulates emitted from railyards in Oregon. Using the most conservative range of the EPA's assessment, we calculate a Pigouvian Tax for the railroad companies to pay, totaling $624.24 per μg/m3 for each person in …

The Energy Policy Act Of 2005: The Rapid Decline Of Jura Majestatis For Communities In Ohio, Alexander Krokus

Hatfield Graduate Journal of Public Affairs

Since Nobel Prize recipient Svante Arrhenius realized that fossil fuel combustion increased CO2 emissions in our atmosphere in 1896, scientists and policy makers have acknowledged the calamitous potential for the oil and gas industry to render substantial deleterious effects on ecosystems. Yet in 2016, the U.S. utilized fossil fuels to facilitate 80.9% of all energy consumption.¹ Subsequent to the passage of the Energy Policy Act of 2005, the Federal Energy Regulatory Commission vastly encouraged outside economic investment into our oil and gas infrastructure. Natural resources situated in geologic formations that possess low permeability, which were once considered previously inaccessible …

Can We Bring Notions Of Groups Back Into Research On Children’S Peer Groups? Differentiating Peer Groups At School According To Their Functions For Academic Development, Anamika J. Vaughan

University Honors Theses

Strategies to examine children’s peer relationships at school can be broadly distinguished into studies of Sociometric Acceptance (Social Status), studies of Social Crowds, studies of Friendship Groups, and studies or Social Networks of frequent interaction partners. Sociometric groups and social crowds are defined as social categories, that is, groups containing students with similar characteristics or lifestyles who often do not share close relationships. In contrast, friendship groups and groups of frequent interaction partners necessitate close and mutual connections between the members of each group.

This study focuses on interaction groups and the ways in which the labels that children assign …

Effect Of Heterogeneity Of Variance On The Performance Of Anova F-Test And Its Alternatives: Simulation Based Study, Jay Lopez

University Honors Theses

Studies have shown that ANOVA F-test has a lower performance against heterogeneity of variances. It is important to provide more information on its alternatives and other methods that can prove useful. As a general guideline, Welch’s ANOVA is a perfect alternative with low type 1 error in all cases of different population variances. An addition to Welch’s ANOVA, Marascuilo’s alternative to this test gives a less accurate result but provides simpler calculation methods. Similar to Moder K. (2010) , Kruskal Wallis test and Hotelling’s T² test were taken into consideration. Kruskal Wallis test had higher type 1 errors similar …

The (Mis)Use Of One-Way Anova Testing In Sociology Research Papers And Their Implications, Nancy Yang

University Honors Theses

Null hypothesis testing has been used increasingly over previous years. Many papers have been released critiquing the use and interpretation of these tests, particularly in the fields of medicine and other physical sciences. This study considers the use of Analysis of Variance (ANOVA) testing, a type of null hypothesis test, in sociology research papers. In this study, peer reviewed research articles have been gathered and analyzed based on their misuse and misinterpretation. Common misuses include proof of the null hypothesis and lack of further explanation of statistically significant results in relation to argument of the research. These interpretations, or lack …

Assessment Of Cluster Chondrite Accretion Temperature Using Electron Backscatter Diffraction And Implications For Chondrule Formation Models, Secana Portia Goudy

Dissertations and Theses

This thesis studies ordinary chondrites with cluster chondrite lithologies using electron backscatter diffraction so as to measure the temperatures of their olivine grains during deformation, for the purpose of constraining the accretion temperatures of cluster chondrites and creating new constraints on chondrule formation models. Samples analyzed with the technique are shock classified in this thesis as S1 and are type 3, so the deformation analyzed is interpreted to represent the temperatures of the chondrules during accretional deformation. It is found that the studied samples are primarily composed of chondrules at hot temperatures (>850°C) during deformation, mixed with a questionable …

Measurements Of N₂O And Sf₆ Mole Fraction And N₂O Isotopic Composition Between 1978 And 1997 In Archived Air Samples From Cape Meares, Oregon, Terry Clinton Rolfe

Dissertations and Theses

Nitrous oxide (N₂O) is the third most important greenhouse gas (GHG) behind carbon dioxide (CO₂) and methane (CH₄). Sulfur hexafluoride (SF₆) does not add significantly to climate forcing by itself due to the low concentration in the atmosphere; however, it is one of the most powerful GHG known. Measurements of atmospheric N₂O made prior to mid-1990 have larger uncertainties than later periods due to advancements made in gas chromatography (GC) methods. Few atmospheric SF₆ measurements pre-1990 exist, especially in the northern hemisphere. Archived samples may be analyzed using updated …

Sensory Relevance Models, Walt Woods

Dissertations and Theses

This dissertation concerns methods for improving the reliability and quality of explanations for decisions based on Neural Networks (NNs). NNs are increasingly part of state-of-the-art solutions for a broad range of fields, including biomedical, logistics, user-recommendation engines, defense, and self-driving vehicles. While NNs form the backbone of these solutions, they are often viewed as "black box" solutions, meaning the only output offered is a final decision, with no insight into how or why that particular decision was made. For high-stakes fields, such as biomedical, where lives are at risk, it is often more important to be able to explain a …

The Spatial And Temporal Evolution Of The Portland And Tualatin Basins, Oregon, Usa, Darby Patrick Scanlon

Dissertations and Theses

The Portland and Tualatin basins are part of the Puget-Willamette Lowland in the Cascadia forearc of Oregon and Washington. The Coast Range to the west has undergone Paleogene transtension and Neogene transpression, which is reflected in basin stratigraphy. To better understand the tectonic evolution of the region, I modeled three key stratigraphic horizons and their associated depocenters (areas of maximum sediment accumulation) through space and time using well log, seismic, outcrop, aeromagnetic, and gravity data. Three isochore maps were created to constrain the location of Portland and Tualatin basin depocenters during 1) Pleistocene to mid-Miocene (0-15 Ma), 2) eruption of …

Indigenous Party Formation And Success: The Strategic Roles Of Reserved Seats, Parties, And Horizontal Accountability, Michael Fitzgerald

Dissertations and Theses

More than twenty legislatures reserve a portion of seats for ethnic minority groups, often in an attempt to prevent violent conflict and redress historical oppression. The intention of reserved seats coincides with indigenous group objectives--to achieve political representation while maintaining autonomy. Yet the formation and electoral success of indigenous parties does not always follow adoption of a reserved seat system. I explain this inconsistency by taking reserved seats as a necessary but insufficient condition of indigenous party formation, and arguing that two additional conditions must be met to motivate indigenous groups to form a viable party: the failure of the …

Architectural And Philosophical 'Makerspace' Redesign Impact On Teacher Beliefs And Practices: A Case Study, Rurik-Rory James Nackerud

Dissertations and Theses

Current jobs in a global economy require more complex cognitive skills, such as critical thinking, cooperation, creativity, and collaboration, in addition to content knowledge. To address these areas, researchers have suggested the use of a 'makerspace' in schools. As with many other establishments, my school remodeled the primary school to create a makerspace for developing these skills. What impact might a makerspace -- a physical as well as a curricular change -- have on teachers' individual and collaborative learning? The purpose of this case study was to describe how the makerspace concept and changes to classroom or instructional space influence …

The Fate Of Atmospherically Deposited Mercury In Mountain Lake Food Webs, And Implications For Fisheries Management, Ariana Martos Chiapella

Dissertations and Theses

Mountain lakes are an iconic feature of the landscape in the Mountain West. They hold significant ecological and cultural value, and are important sentinels of environmental change. Despite their pristine image, these remote waterbodies are subjected to numerous anthropogenic stressors. Mountain lakes are naturally fishless systems, but historical fish stocking has led to major changes in mountain lake food web structure, including declines of resident amphibians, large-bodied zooplankton, and emergent insect populations. Atmospherically deposited contaminants, such as mercury, can accumulate in mountain lake food webs, leading to relatively high levels in the fish relative to the water. Managing for these …

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 …

Drafting In Self-Timed Circuits, Christopher Lee Cowan

Dissertations and Theses

Intervals between data items propagating in self-timed circuits are controlled by handshake signals rather than by a clock. In many self-timed designs, a trailing data item will catch up with a leading item or token, even when it trails by thousands of gate delays. This effect, called "drafting," can be seen in many of the self-timed designs, e.g., GasP, Mousetrap, Click, and Micropipeline. The purpose of this dissertation is to reveal the circuit mechanism of drafting in self-timed circuits typically used in FIFO stages. Drafting is usually considered to be incidental to the operation of self-timed circuits since interval timing …