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Bleached Chondrules And The Possible Influence Of Aqueous Alteration, Robert P. Kostynick

Geology Undergraduate Honors Theses

Aqueous alteration, chemical or petrologic change through the addition of water, is a proposed secondary effect of ordinary chondrites. Some minimally metamorphosed chondrites have been noted to have strong signs of aqueous alteration (Weisberg et al., 2006), but the degree of the effect in other chondrites is not clear. There is a specific chondrule type called “bleached chondrules” in which aqueous alteration is proposed to occur in a widespread fashion for all metamorphic grades (Grossman et al., 2000). Using transmitted optical microscopy (OM) and scanning electron microscopy (SEM) at Portland State University, this report obtained chemical and petrological data of …

Characterizing Tilt Effects On Wind Plants, Ryan Scott

Dissertations and Theses

Tilting the nacelle of a wind turbine modifies entrainment into the wind plant and impacts total efficiency. Extreme angles can produce flying and crashing wakes where the wake either disrupts entertainment from the undisturbed flow above or is decimated on the ground. The effect of tilt angle on downstream wake behavior was investigated in a series of wind tunnel experiments. Scale model turbines with a hub height and diameter of 12 cm were arranged in a Cartesian array comprised of four rows of three turbines each. Nacelle tilt was varied in the third row from -15° to 15° in chosen …

Geothermometry Of H6 And L6 Chondrites And The Relationship Between Impact Processing And Retrograde Metamorphism, Michael Tyler Ream

Dissertations and Theses

Ordinary chondrites are the most common type of meteorite to fall to Earth and are composed of lithified primitive nebular materials which have experienced variable extents of thermal metamorphism and shock processing. They were subjected to radiogenic heating by incorporation of unstable short lived radionuclides such as ²⁶Al in the early solar system.

The relationship between metamorphism and impact processing in ordinary chondrites is not fully understood. An unresolved issue in the study of ordinary chondrites is whether their original parent bodies were fragmented by impacts into rubble-pile bodies while they were still hot, or whether they retained their …

Attitudes, Behavior, And Archetypes In The Clackamas River Basin: A Model Of Water Customer Analysis And Outreach For Watershed Protection And Conservation, Daniel Close Larson

Dissertations and Theses

Fresh water resources around the globe are under threat of diminishing supply and quality due to rapid population growth, climate change, drought, and waste. This dissertation aims to address the protection of fresh water at the source, the tap, and how water customer attitudes influence protection and conservation using a watershed-wide lens. Using the Clackamas River Watershed which resides within the Portland Metropolitan Area (PMA), I seek to investigate water customer attitudes towards a source water protection program and their willingness to pay to support such an endeavor, attitudes and behaviors that result in household water conservation, and an exploration …

Teacher Learning In The Context Of Students’ Mathematical Thinking, Mary Sherrett Duden

Dissertations and Theses

Currently mathematics education is undergoing substantial changes so that students may experience mathematics in intellectually engaging, equitable, and relevant ways. More specifically, I am referring to a teacher stance of centering student thinking and allowing students to make sense of mathematical ideas. Proponents of reform efforts in mathematics argue that this is the path to helping elementary students develop a deep and conceptually sound understanding of mathematics. This is critical because a strong mathematical foundation has increasingly become a gateway for access to many career opportunities and citizenship in the United States.

Unfortunately, these ambitious changes present a challenge for …

Sensors And Portable Instruments For Postharvest Agriculture, Ryan M. Lerud

Dissertations and Theses

The sensing needs for the fresh produce industry can be split into two primary stages: during maturation in the field, also referred to as Precision Farming, and during storage and transport of the produce, or Postharvest Storage. This work seeks to improve the accuracy and reliability of commercially available electrochemical and spectroscopic sensors tailored to the sensing needs of the fresh produce industry. For electrochemical sensing, this study proposes the use of an inline filter to remove polar organic compounds, which can interfere with the readings of a platinum-based electrochemical sensor. A 50% improvement in measurement accuracy was achieved when …

Hydrologic Trends And Spatial Relationships Of Stream Temperature And Discharge In Urbanizing Watersheds In The Portland Metropolitan Area Of The Pacific Northwest, Emma Lee Brenneman

Dissertations and Theses

This study explores various relationships of streamflow and stream temperature over the Portland Metropolitan area in two urbanizing watersheds. Four stream temperature and discharge metrics were derived from USGS stream gauges in the Tualatin River and Johnson Creek watersheds and were analyzed for monotonic trends. Additionally, this study explored the sensitivity of stream temperature to air temperature and streamflow to assess where locations throughout the watershed may be more sensitive to these changes. Relationships among stream temperature, air temperature, and streamflow were assessed using linear and nonlinear bivariate regression for yearly values and summer months. Additionally, this study seeks to …

Physics-Based Signal Processing Methods For Terahertz Non-Destructive Evaluation Of Layered Media, Scott G. Schecklman

Dissertations and Theses

In recent years Terahertz (THz) time domain spectroscopy has emerged as a promising new technology with potential applications in a variety of fields, including industrial manufacturing, security screening and medical imaging. Pulsed THz systems are uniquely suited for non-destructive evaluation (NDE) of the sub-surface layers of dielectric packaging and coating materials, because they provide high dynamic range over a wide bandwidth in the far infrared portion of the electromagnetic spectrum. Often the dielectric materials of the packaging and/or surface coating layers exhibit relatively low loss and abrupt changes in the refractive index at the layer boundaries can be observed as …

Scenes From The Swale: Investigating Spatial And Temporal Dimensions Of Nitrogen Cycling In Urban Stormwater Bioretention Facilities, Erin Nicole Looper

Dissertations and Theses

Urban development is transforming landscapes at unprecedented rates. Human activities and landscape modifications associated with urbanization extensively increase hydrologic demands and modify natural hydrologic systems; consequently, population growth occurring in urban areas increases pressure on water resources. Urban aquatic ecosystems are vulnerable to impacts associated with increased connectivity with urban surfaces and hydrologic changes that initiate long-term changes in receiving waterbodies. Nitrogen (N) loading from urban and suburban catchments to receiving surface waters can lead to impairment of aquatic ecosystems and is a concern in many cities with water quality issues. To improve urban water quality, cities are increasingly adopting …

Material Parameter Estimation Of Thin Wafers With Terahertz Time-Domain Spectroscopy, Kirk R. Jungles

Maseeh Summer Undergraduate Research Experience

Terahertz Time Domain Spectroscopy(THz TDS) is a spectroscopic technique that can be implemented to perform non destructive material parameter extraction on a variety of materials. Accuracy of these material parameters is often limited by statistical variation between measurements and insufficient knowledge of the thickness of the slabs being measured.

The goal of this project was to develop an in house procedure that would allow us to perform THz TDS on thin wafers using an up to date signal processing algorithm that would provide accurate predictions for the thickness of the wafers, reliable estimations of the wafer’s material parameters, and demonstration …

Photoelectrochemical Catalysis Of Hydrogen Peroxide With Tellurium Containing Chromophores, James Eliott Lohman

Dissertations and Theses

Growing concerns over climate change and demand for energy worldwide have made development and implementation of alternative energy sources more necessary than ever. Many of the leading energy alternatives suffer from inconsistent energy production due to fluctuations in availability of natural resources, and the current methods of addressing the issue have tremendous ecological and social ramifications of their own. While fuels like hydrogen gas are providing some promise of relief, the scope of infrastructure changes necessary for implementation and the implicit hazards of the use of such fuels complicate their application as an immediate solution. However, hydrogen peroxide carries far …

Uhf And Microwave Phase-Modulated Scattering Array, Nasr Nomas Hussein Alkhafaji

Dissertations and Theses

This dissertation investigates the use an array of active nonlinear elements, with particular emphasis on controlling distortion products generated by nonlinear elements in space rather than using conventional ways such as transmission lines, waveguides, and power dividers and combiners. The nonlinear elements are made of assemblies of antennas and electronic switches, called modulated scatterers (MSs). These so-called MSs elements are utilized in a wide variety of applications such as radio frequency identification (RFID) systems, microwave imaging, Internet-of-Things sensors, etc. However, no research work has been reported in the literature regarding exploiting and controlling several distortion products generated by MSs at …

Analytical And Numerical Modeling Of Long Term Changes To Tides, Storm Surge, And Total Water Level Due To Bathymetric Changes And Surge Characteristics, Ramin Familkhalili

Dissertations and Theses

Natural and local anthropogenic changes in estuaries (e.g., sea-level rise, navigation channel construction and loss of wetlands) interact with each other and produce non-linear effects. There is also a growing recognition that tides in estuaries are not stationary. These factors together are changing the estuarine water level regime, however the implications for extreme water levels remain largely unknown. Changes over the past century in many estuaries, such as channel deepening and streamlining for navigation have significantly altered the hydrodynamics of long waves, often resulting in amplified tides (a ~85% increase in Wilmington, NC since 1900) and storm surge in estuaries. …

Next Generation Science Standards And Physics First: A Case Study Of High School Teachers' Beliefs And Practices, Stephen Godfrey Scannell

Dissertations and Theses

This dissertation is a case study of a school district in the Pacific Northwest that developed three-year high school science curricula using a Physics First course sequence (Physics, Chemistry, Biology), with the crosscutting concept Patterns as the central theme of the courses. The purpose of the study was to examine the impact of the implementation of the 9th grade course, Patterns Physics, on teacher practice and beliefs about science teaching and determine whether this new approach facilitated teacher classroom practices and beliefs congruent with those expressed in A Framework for K-12 Science Education (NRC, 2012) and the Next Generation Science …

Context-Aware Wi-Fi Infrastructure-Based Indoor Positioning Systems, Huy Phuong Tran

Dissertations and Theses

Large enterprises are often interested in tracking objects and people within buildings to improve resource allocation and occupant experience. Infrastructure-based indoor positioning systems (IIPS) can provide this service at low-cost by leveraging already deployed Wi-Fi infrastructure. Typically, IIPS perform localization and tracking of devices by measuring only Wi-Fi signals at wireless access points and do not rely on inertial sensor data at mobile devices (e.g., smartphones), which would require explicit user consent and sensing capabilities of the devices.

Despite these advantages, building an economically viable cost-effective IIPS that can accurately and simultaneously track many devices over very large buildings is …

Distribution And Origin Of Carbide In Ordinary Chondrites, Karla Rae Farley

Dissertations and Theses

To understand the occurrence and distribution of carbide minerals in ordinary chondrites, thirty meteorites were examined, twenty-eight ordinary chondrites and two iron meteorites. The occurrence of carbide, textures, and chemical compositions were examined in the 7 carbide-bearing meteorites. Two formation methods for carbide have been presented in previous research. These are aqueous alteration and shock heating, and they are examined for validity in this thesis. Additionally, one other formation method for carbide formation through impact and brecciation is put forth and examined. Textural differences between the carbide-magnetite assemblages (CMAs) observed by Krot et al., (1997) and those seen in this …

An Investigation Of The Impact Of High School Student Fine Arts Course Accumulation On Mathematics Course Achievement, Daniel Mackin Freeman

Dissertations and Theses

Science, technology, engineering, and mathematics (STEM) educational achievement is vital to economic competitiveness in the United States and abroad. Despite a concerted effort, the US lags well behind many similarly developed nations. Research suggests that the integration of fine arts education into traditional STEM curriculum (STEAM) boosts academic achievement in STEM subjects and closes gaps between low- and high-socioeconomic status students. Justifications for STEAM programs are based, however, on the unexamined assumption, for one, that fine arts courses instill creative and critical thinking skills that can be transferred to STEM subjects. The present study explores the impact of taking fine …

"It's All Because I Like The Person That's Teaching Me": Masculinities, Engagement, And Caring Relationships In Secondary Schools, Cristy Lauren Weggelaar

Dissertations and Theses

U.S. schools face a well-documented gender gap within some important educational and social indicators. In the United States, boys and young men are significantly more likely than girls and young women to be diagnosed with a learning disability, leave high school without a diploma, receive failing grades in core classes, and be suspended or expelled from school. This study uses an interpretive research framework to investigate the relationship between this gender gap in education and constructions of masculinity, social and cultural capital, agency, caring and resistance in secondary schools. Data collected through interviews with young men who engaged in acts …

Learning From Culturally Specific Programs And Their Impact On Latino Parent Engagement, Analucia Lopezrevoredo

Dissertations and Theses

Latinos are the largest and fastest growing ethnic minority group in the United States. Academically, they are significantly trailing their non-Latino peers in graduation and overall educational attainment. Among many socioeconomic factors, parent engagement has been identified as being a defining indicator of student success. Reflective of racial and class disparities, this study explored with the use of critical race and intersectionality theory, that low Latino parent engagement is a result of the historical devaluing and omission of Latino culture, history and language from formal academic settings, and compounding social factors that make engagement complex for Latino immigrants in America …

Memcapacitive Reservoir Computing Architectures, Dat Tien Tran

Dissertations and Theses

In this thesis, I propose novel brain-inspired and energy-efficient computing systems. Designing such systems has been the forefront goal of neuromorphic scientists over the last few decades. The results from my research show that it is possible to design such systems with emerging nanoscale memcapacitive devices.

Technological development has advanced greatly over the years with the conventional von Neumann architecture. The current architectures and materials, however, will inevitably reach their physical limitations. While conventional computing systems have achieved great performances in general tasks, they are often not power-efficient in performing tasks with large input data, such as natural image recognition …

Nutrients Mediate The Effects Of Temperature On Methylmercury Concentrations In Freshwater Zooplankton, Meredith P. Jordan, A. Robin Stewart, Collin A. Eagles-Smith, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and nutrient enrichment. The goal of this study was to determine how warmer water temperatures and excess nutrients would alter zooplankton communities and phytoplankton concentrations, and whether those changes would in turn increase or decrease MeHg concentrations in freshwater zooplankton. To test this, we employed a 2 × 2 factorialexperimental design with nutrient and temperature treatments. Mesocosms were filled with ambient water and plankton from Cottage Grove Reservoir, Oregon, U.S.A., a waterbody that has experienced decades of elevated MeHg concentrations and …

A Landscape Model Of Variable Social-Ecological Fire Regimes, Robert M. Scheller, Alec M. Kretchun, Todd J. Hawbaker, Paul D. Henne

Environmental Science and Management Faculty Publications and Presentations

Fire regimes are now recognized as the product of social processes whereby fire on any landscape is the product of human-generated drivers: climate change, historical patterns of vegetation manipulation, invasive species, active fire suppression, ongoing fuel management efforts, prescribed burning, and accidental ignitions. We developed a new fire model (Social-Climate Related Pyrogenic Processes and their Landscape Effects: SCRPPLE) that emphasizes the social dimensions of fire and enables simulation of fuel-treatment effects, fire suppression, and prescribed fires. Fire behavior was parameterized with daily fire weather, ignition, and fire-boundary data. SCRPPLE was initially parameterized and developed for the Lake Tahoe Basin (LTB) …

Climate And Lawn Management Interact To Control C4 Plant Distribution In Residential Lawns Across Seven U.S. Cities, Tara Trammell, Diane E. Pataki, Christopher Still, James Ehleringer, Meghan Avolio, Jennifer L. Morse, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

In natural grasslands, C4 plant dominance increases with growing season temperatures and reflects distinct differences in plant growth rates and water use efficiencies of C3 vs. C4 photosynthetic pathways. However, in lawns, management decisions influence interactions between planted turfgrass and weed species, leading to some uncertainty about the degree of human vs. climatic controls on lawn species distributions. We measured herbaceous plant carbon isotope ratios (δ13C, index of C3/C4 relative abundance) and C4 cover in residential lawns across seven U.S. cities to determine how climate, lawn plant management, or interactions between climate and plant management influenced C4 lawn cover. We …

Utilizing Parallelism In The Conjugate Gradient Algorithm, Adam James Craig

University Honors Theses

This paper develops the original conjugate gradient method and the idea of preconditioning a system. I also propose a unique type of additive-Schwarz preconditioner that can be solved in parallel, which creates a speed increase for large systems. To show this, I developed a C++11 linear algebra library used in conjunction with the OpenMP parallel computing library to empirically show a speed increase.

A Computational Model For Recovery From Traumatic Brain Injury, Wayne Wakeland, Erin S. Kenzie

Complex Systems Faculty Publications and Presentations

A computational simulation model calculates estimated recovery trajectories following traumatic brain injury (TBI). Prior publications include a multi-scale conceptual framework for studying concussion, a systems-level causal loop diagram (CLD) and an analysis of key feedback processes. A set of first order ordinary differential equations and their associated parameters determines recovery trajectories. The model contains 15 state variables, 73 auxiliary variables, and 50 parameters describing TBI pathology in an aggregate fashion at the cellular, network, cognitive and social levels. There are 1200 feedback loops, which give rise to a variety of behavior modes, many of which are highly nonlinear. Exogenous parameters …

Dementia-Related Neuropsychological Testing Considerations In Non-Hispanic White And Latino/Hispanic Populations, Shanna L. Burke, Mitra Naseh, Miriam Rodriguez, Aaron Burgess, David Loewenstein

School of Social Work Faculty Publications and Presentations

Hispanic individuals are at greater risk for health disparities, less than optimal health care, and are diagnosed at later stages of cognitive impairment than white non-Hispanics. Acculturation and different attitudes toward test-taking may result in decrements in performance, especially on unfamiliar measures that emphasize speed and accuracy. Non-Hispanic individuals often outperform Hispanic individuals on cognitive and neuropsychological measures in community and clinical populations. Current neuropsychological testing may not provide accurate data related to monolingual and bilingual individuals of Hispanic descent. Testing instruments were identified by searching academic databases using combinations of relevant search terms. Neuropsychological instruments were included if they …

Event Trend Aggregation Under Rich Event Matching Semantics, Olga Poppe, Chuan Lei, Elke A. Rundensteiner, David Maier

Computer Science Faculty Publications and Presentations

Streaming applications from cluster monitoring to algorithmic trading deploy Kleene queries to detect and aggregate event trends. Rich event matching semantics determine how to compose events into trends. The expressive power of stateof- the-art streaming systems remains limited since they do not support many of these semantics. Worse yet, they suffer from long delays and high memory costs because they maintain aggregates at a fine granularity. To overcome these limitations, our Coarse-Grained Event Trend Aggregation (Cogra) approach supports a rich variety of event matching semantics within one system. Better yet, Cogra incrementally maintains aggregates at the coarsest granularity possible for …

E-Cigarette Chemistry And Analytical Detection, Robert M. Strongin

Chemistry Faculty Publications and Presentations

The study of e-cigarette aerosol properties can inform public health while longer-term epidemiological investigations are ongoing. The determination of aerosol levels of known toxins, as well as of molecules with unknown inhalation toxicity profiles, affords specific information for estimating the risks of e-cigarettes and for uncovering areas that should be prioritized for further investigation.

Graceful Infrastructure: Harvesting America's Wind Corridor, Samuel Rothacker

University Honors Theses

The central purpose of this thesis was to identify how the choices made by wind farm developers lead to backlash from local community members, focusing primarily on a resistance mentality referred to as NIMBY (Not In My Backyard). The goal of this discussion is to offer wind farm developers a medium by which to understand the causes and concerns of the NIMBY movement, as well as what steps can be taken to address or prevent these issues. Research was pursued by selecting a number of wind farms and searching for correlations between technical specifications and political backlash. By first collecting …

Exo-Genres: Case Study Of Oregon State’S ‘Stage-Gate’ It Review Process, Henry Covey

Technical and Professional Writing Graduate Student Papers

This is a preliminary case study of exogenres, specifically superimposed genre exosystems, i.e., genre frameworks that are prescribed (genre exosystems) which are “laid upon” (superimposed on) writing scenes from outside oversight entity/ies.

This case study gathered and analyzed artifacts, data, and information from a relatively new exosystem in the Oregon state government: the IT project approval process called “Stage Gate,” a mandated regulatory reporting documentation process in effect in Oregon since 2015. The exogenres in Stage Gate were created out of a social action to superimpose IT governance and industry frameworks on state government agencies who build enterprise …