Digital Commons Network^™

Photoemission Electron Microscopy For Analysis Of Dielectric Structures And The Goos-Hänchen Shift, Theodore Axel Stenmark

Dissertations and Theses

Photoemission Electron Microscopy (PEEM) is a versatile tool that relies on the photoelectric effect to produce high-resolution electron images. Ultrafast pulse lasers allow for multi-photon PEEM where multiple visible or IR photons excite a single electron in a nonlinear process. The photoelectron yield in both cases is related to the near-field region of electromagnetic fields at the surface of the sample. We use this ability here to analyze wave propagation in a linear dielectric waveguide with wavelengths of 410 nm and 780 nm. The propagation constant of the waveguide can be extracted from interference patterns created by light propagating in …

Large Length Scale Capillary Fluidics: From Jumping Bubbles To Drinking In Space, Andrew Paul Wollman

Dissertations and Theses

In orbit, finding the "bottom" of your coffee cup is a non-trivial task. Subtle forces often masked by gravity influence the containment and transport of fluids aboard spacecraft, often in surprising non-intuitive ways. Terrestrial experience with capillary forces is typically relegated to the micro-scale, but engineering community exposure to large length scale capillary fluidics critical to spacecraft fluid management design is low indeed. Low-cost drop towers and fast-to-flight International Space Station (ISS) experiments are increasing designer exposure to this fresh field of study. This work first provides a wide variety of drop tower tests that demonstrate fundamental and applied capillary …

An Examination Of School Readiness: How Is The Construct Defined For Children Who Are Blind?, Lisa Joann Mcconachie

Dissertations and Theses

An increased focus on school readiness exists as students enter public school for the first time. Given unique challenges for students who are blind and use braille, school readiness in the transition to and preparation for kindergarten is even more critical to their future academic success. If children who are blind and use braille as their primary learning medium have the necessary school readiness skills entering kindergarten, they will be better prepared to participate in the academic classroom. There is a need for additional research to illuminate the skills needed for school readiness for children who are blind and use …

Development Of Middle School Teachers' Knowledge And Pedagogy Of Justification: Three Studies Linking Teacher Conceptions, Teacher Practice, And Student Learning, Carolyn Mccaffrey James

Dissertations and Theses

Justification and argumentation have been identified as important mathematical practices; however, little work has been done to understand the knowledge and pedagogy teachers need to support students in these ambitious practices. Data for this research was drawn from the Justification and Argumentation: Growing Understanding in Algebraic Reasoning (JAGUAR) project. JAGUAR was a multi-year research and professional development project in which 12 middle school math teachers and a group of researchers explored the knowledge and pedagogy needed to support student justifications. This dissertation consists of three case study analyses. The first paper describes the development of teacher conceptions of justification, including …

Factors Driving The Concentration Of Ephemeral Flow, Gretchen Anne Guyer

Dissertations and Theses

In spite of decades of related research, stream channel initiation is still not well understood. Current theories of channel initiation are grounded in research conducted by Montgomery and Dietrich, largely in the transport limited, temperate, humid climate of the Pacific Northwest, USA. This field data driven work concluded that the drainage area required for channel initiation is directly correlated to the slope of the contributing area. However, there are a host of related variables that have yet to be examined in the field. This study revisits the slope-area relationship focusing on ephemeral overland flow in headwaters of both the Pacific …

Origin And Use Of Pedagogical Content Knowledge: A Case Study Of Three Math Teachers And Their Students, Christopher Neal Wood

Dissertations and Theses

Teachers must have specific knowledge of a subject and how to teach it to promote learning in their students (also known as pedagogical content knowledge). Research has shown that project-based curriculum can be an effective way for teachers to leverage this knowledge into deeper student understanding and application readiness, but observations about when and how this happens in the classroom have not been adequately documented. In this study we will explore teaching and learning in a middle-school boat-building curriculum focused on real-world application of math concepts. The boat-building program took place over one week, included seven students, and was taught …

Relationships That Extend Beyond The Fence-Line: Private Landowner Attitudes And Interest In Conservation Easements, Ashley Lyn Vizek

Dissertations and Theses

Private land conservation provides an opportunity to address problems of habitat fragmentation and biodiversity loss caused by an increase in the development and parcelization of private land. Conservation easements (CEs) are an innovative tool used by land trusts to protect significant natural qualities of private land in perpetuity, while also allowing the land to remain in private ownership. Traditionally, property represents an individualistic relationship, however, CEs redefine this relationship by seeking to maximize the overlap in private and public goods in property. In this study, I explore the relationship between the common good and private property through an analysis of …

"That's The Test?" Washback Effects Of An Alternative Assessment In A Culturally Heterogeneous Eap University Class, Abigail Bennett Carrigan

Dissertations and Theses

To determine learner attitudes toward an alternative assessment, additional washback effects, and possible relationships between cultures of learning and learner attitudes, a mixed methods study was conducted in an advanced multicultural EAP (English for Academic Purposes) class in the USA, where a poster project was implemented as a summative assessment. Qualitative and quantitative data from a pre- and post-test questionnaire as well as classroom observations and an interview with the instructor were used to investigate learners' attitudes towards the assessment. The twenty-four participants representing five cultures of learning from the Middle East, South America and Southeast Asia expressed largely positive …

Event Detection Using Correlation Within Arrays Of Streaming Pmu Data, Jordan Landford

Dissertations and Theses

This thesis provides a synchrophasor data analysis methodology that leverages both statistical correlation techniques and a statistical distribution in order to identify data inconsistencies, as well as power system contingencies. This research utilizes archived Phasor Measurement Unit (PMU) data obtained from the Bonneville Power Administration in order to show that this methodology is not only feasible, but extremely useful for power systems monitoring, decision support, and planning purposes.

By analyzing positive sequence voltage angles between a pair of PMUs at two different substation locations, an historic record of correlation is established. From this record, a Rayleigh distribution of correlation coefficients …

The Intermediate Value Theorem As A Starting Point For Inquiry-Oriented Advanced Calculus, Stephen Raymond Strand Ii

Dissertations and Theses

Making the transition from calculus to advanced calculus/real analysis can be challenging for undergraduate students. Part of this challenge lies in the shift in the focus of student activity, from a focus on algorithms and computational techniques to activities focused around definitions, theorems, and proofs. The goal of Realistic Mathematics Education (RME) is to support students in making this transition by building on and formalizing their informal knowledge. There are a growing number of projects in this vein at the undergraduate level, in the areas of abstract algebra (TAAFU: Larsen, 2013; Larsen & Lockwood, 2013), differential equations (IO-DE: Rasmussen & …

Social Capital And Cultural Identity For U.S. Korean Immigrant Families: Mothers' And Children's Perceptions Of Korean Language Retention, Su-Jin Sue Jung

Dissertations and Theses

Through increasing immigration, the U.S. society is becoming more linguistically and culturally diverse. Yet, as many U.S. language minority groups seek to assimilate, they face many challenges. One challenge is that their home language does not match the dominant language, English, that their children are learning at school. For Korean communities, maintaining Korean language presents a problem for families, especially for the mothers and children. The purpose of this study was to explore the U.S. Korean immigrant mothers' and children's perceptions of and experience with maintaining the Korean language and the effect that has on the development of social capital …

Intercultural Interactions Among Burmese Refugees In Multicultural Middle School Classrooms, Matthew Carl Mcparker

Dissertations and Theses

The largest refugee group entering the United States in recent years is from Burma. Refugee students face a daunting set of challenges, from language and cultural differences to living in poverty, in becoming successful in their new homes. To be successful in schools and gain cultural and social capital, refugee students must learn and internalize the specific norms of their classrooms. In middle school, students are particularly reliant upon their peers for support, making peer interactions especially important. In multicultural settings, students have ample opportunities for intercultural interactions, which can help refugee students navigate their new settings and become more …

The Importance Of Online Peer Relationships During The Transition To Motherhood: Do They Decrease Stress, Alleviate Depression And Increase Parenting Competence?, Bobbie Sue Arias

Dissertations and Theses

This research addressed the challenges faced by women in today's society during the transition to motherhood, and explored the possible benefits of an online natural helping network of blogging peers. Given the content of the literature describing the transition to motherhood and the many hardships that pose possible obstacles for an ideal transition, this research attempted to uncover the reasons why mothers blog and what benefit, if any, they experience as a result of blogging. This study explored the following questions: Why do women blog during the transition to motherhood? What is the relationship among the seven identified variables: blogging …

The Effects Of Phosphonic Acids In Dye-Sensitized Solar Cells, Keith Edward James

Dissertations and Theses

Novel methods for the construction of dye-sensitized solar cells (DSSCs) were developed. A thin dense underlayer of TiO₂ was applied on fluorine-doped tin oxide (FTO) glass using as a precursor Tyzor AA-105. Subsequently a mesoporous film of P-25 TiO₂ was applied by spreading a suspension uniformly over the surface of the underlayer and allowing the plate to slowly dry while resting on a level surface. After sintering at 500° C slides were treated with TCPP as a sensitizing dye and assembled into DSSCs. A novel method was used to seal the cells; strips of Parafilm® were used as …

Green Roofs And Urban Biodiversity: Their Role As Invertebrate Habitat And The Effect Of Design On Beetle Community, Sydney Marie Gonsalves

Dissertations and Theses

With over half the world's population now living in cities, urban areas represent one of earth's few ecosystems that are increasing in extent, and are sites of altered biogeochemical cycles, habitat fragmentation, and changes in biodiversity. However, urban green spaces, including green roofs, can also provide important pools of biodiversity and contribute to regional gamma diversity, while novel species assemblages can enhance some ecosystem services. Green roofs may also mitigate species loss in urban areas and have been shown to support a surprising diversity of invertebrates, including rare and endangered species. In the first part of this study I reviewed …

The "Adam Cube" : Categorizing Portland, Oregon's Urbanization Using Gis And Spatial Statistics, Jeremy Grotbo

Dissertations and Theses

Transportation availability and land use intensity demonstrate a strong relationship, with intense development concentrated near significant transportation investment. Transportation networks evolved in response to emergent transportation technologies and changing urban land uses. The irregular distribution of transportation systems reinforced patterns of land use development, shaping urban form. Understanding the relationships between transportation and the intensity of land uses allows urban geographers and city planners to explain the urbanization processes, as well as to identify areas historically susceptible to future development. The goal of this research is to develop a quantitative framework for the analysis of the development of urban form …

Developing A Hierarchical Decision Model To Evaluate Nuclear Power Plant Alternative Siting Technologies, Marwan Mossa Lingga

Dissertations and Theses

A strong trend of returning to nuclear power is evident in different places in the world. Forty-five countries are planning to add nuclear power to their grids and more than 66 nuclear power plants are under construction.

Nuclear power plants that generate electricity and steam need to improve safety to become more acceptable to governments and the public. One novel practical solution to increase nuclear power plants' safety factor is to build them away from urban areas, such as offshore or underground. To date, Land-Based siting is the dominant option for siting all commercial operational nuclear power plants. However, the …

An Investigation Of Invasion: Boater Knowledge Concerning Aquatic Invasive Species And The Influence Of The New Zealand Mud Snail On Benthic Food Webs, Samuel Anthony Cimino

Dissertations and Theses

Invasive species are second only to habitat loss as a leading cause of native species displacement and the management of invasive species costs hundreds of billions annually. Invasion is often conceptualized as a series of stages (Transport, Introduction, Establishment, and Spread), which encourages ecologists to isolate factors that might enable a species to pass from one stage to another and therefore guide prevention or impact management. This thesis addresses each stage of invasion and attempts to determine where management might succeed in preventing invasion or minimizing impacts. The transport and introduction of aquatic invasive species (AIS) was analyzed by conducting …

The Development And Validation Of The Social Recovery Measure, Casadi "Khaki" Marino

Dissertations and Theses

Mental health recovery is a complex phenomenon involving clinical, functional, physical, and social dimensions. The social dimension is understood to involve meaningful relationships and integration with supportive individuals and a wider community. While the recovery model developed from a movement led by consumers and survivors of the mental health system to promote hope, self-determination, and social inclusion, the clinical aspects of recovery have dominated mental health research and practice. The under-investigated area of social recovery calls for psychometrically sound measurement instruments. The purpose of the current study was to develop and validate the Social Recovery Measure (SRM). The study was …

Investigating The Effects Of 17Α-Ethynylestradiol On Mitochondrial Genome Stability, Alicia M. Chivers

Dissertations and Theses

Environmental toxicants are ubiquitous throughout the environment as a result of human activity. Among these toxicants, environmental estrogens are a category of particular concern due to their environmental prevalence and potency in altering reproductive traits. While many studies have addressed the detrimental effects of environmental estrogens on both aquatic and terrestrial organisms, few have analyzed the potential for these compounds to alter mitochondrial function. Mitochondria are the primary energy-generating system for all eukaryotic life, supporting all aspects of development, metabolism, and growth. Each cell within the body contains many mitochondria which in turn contain multiple copies of their own DNA …

Accuracy Of Wave Speeds Computed From The Dpg And Hdg Methods For Electromagnetic And Acoustic Waves, Nicole Michelle Olivares

Dissertations and Theses

We study two finite element methods for solving time-harmonic electromagnetic and acoustic problems: the discontinuous Petrov-Galerkin (DPG) method and the hybrid discontinuous Galerkin (HDG) method.

The DPG method for the Helmholtz equation is studied using a test space normed by a modified graph norm. The modification scales one of the terms in the graph norm by an arbitrary positive scaling parameter. We find that, as the parameter approaches zero, better results are obtained, under some circumstances. A dispersion analysis on the multiple interacting stencils that form the DPG method shows that the discrete wavenumbers of the method are complex, explaining …

Physics-Based Imaging Methods For Terahertz Nondestructive Evaluation Applications, Gabriel Paul Kniffin

Dissertations and Theses

Lying between the microwave and far infrared (IR) regions, the "terahertz gap" is a relatively unexplored frequency band in the electromagnetic spectrum that exhibits a unique combination of properties from its neighbors. Like in IR, many materials have characteristic absorption spectra in the terahertz (THz) band, facilitating the spectroscopic "fingerprinting" of compounds such as drugs and explosives. In addition, non-polar dielectric materials such as clothing, paper, and plastic are transparent to THz, just as they are to microwaves and millimeter waves. These factors, combined with sub-millimeter wavelengths and non-ionizing energy levels, makes sensing in the THz band uniquely suited for …

Evaluating An Assessment Instrument For The Oregon Environmental Literacy Plan, Susan Mae Duncan

Dissertations and Theses

This mixed methods study evaluated the validity, and reliability of an instrument designed to assess a middle school student's proficiency in systems thinking as described in the 2010 Oregon Environmental Literacy Plan. In Stage 1, a forum of middle school students, formal, and non-formal educators used the Delphi technique to reach consensus regarding which skills were important to include in a scoring guide for systems thinking. In Stage 2, the scoring guide was field tested by formal and non-formal educators using a sample of students' work. The two groups' scores were compared using Cohen's kappa to make inferences regarding inter-rater …

Investigations Of An "Objectness" Measure For Object Localization, Lewis Richard James Coates

Dissertations and Theses

Object localization is the task of locating objects in an image, typically by finding bounding boxes that isolate those objects. Identifying objects in images that have not had regions of interest labeled by humans often requires object localization to be performed first. The sliding window method is a common naïve approach, wherein the image is covered with bounding boxes of different sizes that form windows in the image. An object classifier is then run on each of these windows to determine if each given window contains a given object. However, because object classification algorithms tend to be computationally expensive, it …

On The Variability Of Pacific Ocean Tides At Seasonal To Decadal Time Scales: Observed Vs Modelled, Adam Thomas Devlin

Dissertations and Theses

Ocean tides worldwide have exhibited secular changes in the past century, simultaneous with a global secular rise in mean sea level (MSL). The combination of these two factors contributes to higher water levels, and may increase threats to coastal regions and populations over the next century. Equally as important as these long-term changes are the short-term fluctuations in sea levels and tidal properties. These fluctuations may interact to yield locally extreme water level events, especially when combined with storm surge. This study, presented in three parts, examines the relationships between tidal anomalies and MSL anomalies on yearly and monthly timescales, …

Tree Graphs And Orthogonal Spanning Tree Decompositions, James Raymond Mahoney

Dissertations and Theses

Given a graph G, we construct T(G), called the tree graph of G. The vertices of T(G) are the spanning trees of G, with edges between vertices when their respective spanning trees differ only by a single edge. In this paper we detail many new results concerning tree graphs, involving topics such as clique decomposition, planarity, and automorphism groups. We also investigate and present a number of new results on orthogonal tree decompositions of complete graphs.

Introducing Complex Systems Analysis In High School Mathematics Using System Dynamics Modeling: A Potential Game-Changer For Mathematics Instruction, Diana Marie Fisher

Dissertations and Theses

Complex systems abound on this planet, in the composition of the human body, in ecosystems, in social interaction, in political decision-making, and more. Analytical methods allowing us to better understand how these systems operate and, consequently, to have a chance to intervene and change the undesirable behavior of some of the more pernicious systems have developed and continue to be enhanced via quickly changing technology. Some of these analytical methods are accessible by pre-college students, but have not been widely used at that level of education. Jay Forrester, the founder of one of the methodologies, System Dynamics (SD), used to …

The Use Of Anti-Bullying Policies To Protect Lgbt Youth: Teacher And Administrator Perspectives On Policy Implementation, Michelle Lauren Holliday

Dissertations and Theses

Although in recent years there has been increased attention on bullying prevention and bullying legislation in the United States, there is limited research on the implementation of anti-bullying policies. Moreover, few studies have addressed the use of anti-bullying policies to protect LGBT youth from bullying. The present study seeks to examine the role of anti-bullying policies as a means to protect against bullying based on perceived sexual orientation and gender identity. Qualitative interviews with high school teachers, administrators, and staff members within an urban school district in the United States were conducted to gain insight into how those charged with …

The Foundations Of Network Dynamics In An Rna Recombinase System, Jessica Anne Mellor Yeates

Dissertations and Theses

How life originated from physical and chemical processes is one of the great questions still unanswered today. Studies towards this effort have transitioned from the notion of a single self-replicating entity to the idea that a network of interacting molecules made this initial biological leap. In order to understand the chemical kinetic and thermodynamic mechanisms that could engender pre-life type networks we present an empirical characterization of a network of RNA recombinase molecules. We begin with 1-, 2-, and 3-molecular ensembles and provide a game theoretic analysis to describe the frequency dependent dynamics of competing and cooperating RNA genotypes. This …

Discrete Stability Of Dpg Methods, Ammar Harb

Dissertations and Theses

This dissertation presents a duality theorem of the Aubin-Nitsche type for discontinuous Petrov Galerkin (DPG) methods. This explains the numerically observed higher convergence rates in weaker norms. Considering the specific example of the mild-weak (or primal) DPG method for the Laplace equation, two further results are obtained. First, for triangular meshes, the DPG method continues to be solvable even when the test space degree is reduced, provided it is odd. Second, a non-conforming method of analysis is developed to explain the numerically observed convergence rates for a test space of reduced degree. Finally, for rectangular meshes, the test space is …