Index Catalog // ScholarsArchive@OSU

Cross-section fatal crash type prediction models

Creator:: Zhu, Hong
Abstract:: The rural two-lane highway in the southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes. The major research objectives are to investigate the relations between probabilities of fatal crash type occurrence and potential contributing factors from road geometric design characteristics and roadside, environmental features....
Resource Type:: Dissertation

Synthesis and characterization of magnetic composite materials

Creator:: Kimmell, Robert
Abstract:: Iron epoxy composite materials were made and their relative magnetic permeability was measured. A measurement device was created to measure the relative magnetic permeability for the specific application. This device proved to be accurate and reliable. The magnetic properties of composite materials have been shown to be controllable, with a...
Resource Type:: Masters Thesis

Mortality threshold for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an epidemiological model of Ceratomyxa shasta

Creator:: Ray, R. Adam
Abstract:: The myxozoan parasite, Ceratomyxa shasta, is the most significant pathogen of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River, CA, USA. This parasite requires two hosts - a freshwater polychaete (Manayunkia speciosa) and a salmonid - to complete its life cycle. The complex life cycle and large geographic area...
Resource Type:: Masters Thesis

Nature in chains : the effects of Thomas Jefferson’s rectangular survey on a Pacific Northwest landscape

Creator:: Schweickert, Tina K.
Abstract:: Understanding the impact of humans on the environment has long been a topic of scholarly interest and debate. As environmental problems mount, accounts of historic ecological conditions and the factors of change become increasingly useful. This study considers competing schools of interpretation about human impacts on ecological landscapes and develops...
Resource Type:: Masters Thesis

A novel method for zinc oxide nanowire sensor fabrication

Creator:: Pelatt, Brian D.
Abstract:: Interest in nanomaterials is motivated partly by their potential for sensor arrays to detect different gases. Nanowires in particular are of interest because their high surface-to-volume ratio promises the possibility of high sensitivity. However, because of their discrete quasi-one-dimensional geometry, electrical integration of nanowires into photolithographically defined devices and circuits...
Resource Type:: Masters Thesis

Description and analysis of dietary preference of lingcod in the nearshore zone, Oregon

Creator:: Tinus, Craig A.
Abstract:: The lingcod (Ophiodon elongatus) is an important groundfish species in both recreational and commercial fisheries of the Northeastern Pacific. It is a large, fast-growing, generalist predator of invertebrates and fishes. In response to concerns that lingcod may limit populations of rockfishes (Sebastes spp.), I compared the diets of 375 adult...
Resource Type:: Dissertation

Ecological interrelationships between summer resident gray whales (Eschrichtius robustus) and their prey, mysid shrimp (Holmesimysis sculpta and Neomysis rayi) along the central Oregon coast

Creator:: Newell, Carrie
Abstract:: The ecological interaction between the largest coastal predator, the gray whale (Eschrichtius robustus) and the most abundant shallow water marcrozooplanktonic prey, mysids, were examined in a poorly-understood predator-prey relationship along the central Oregon coast. From 2002-2008, 83 seasonal gray whales were identified. These whales returned each year around Memorial Day...
Resource Type:: Masters Thesis

Reported Communication Experiences of Married Women Transitioning to Motherhood: A Case Study

Creator:: Hanna, Sarah Elizabeth
Abstract:: This thesis investigates the reported communication experiences of married women transitioning to motherhood. The study involves a series of focus groups in which new mothers share their communicative experiences, explaining how they are navigating their new roles as mothers while also performing roles as wives, daughters, and workers. Informed primarily...
Resource Type:: Masters Thesis

Forest biomass estimation with hemispherical photography for multiple forest types and various atmospheric conditions

Creator:: Clark, Joshua Andrew
Abstract:: The importance of accurately identifying inventories of domestic energy, including forest biomass, has increasingly become a priority of the US government and its citizens as the cost of fossil fuels has risen. It is useful to identify which of these resources can be processed and transported at the lowest cost...
Resource Type:: Dissertation

Efficient RF energy scavenging and ultra-low power management for powering wireless sensor nodes

Creator:: Arumugam, Vikrant P.
Abstract:: As the demand for real-time information in engineering and health care systems keeps increasing, the need for wireless sensor nodes is also continuously increasing. As a result, the cost and effort involved in installing and maintaining batteries to power the numerous sensor nodes is growing exponentially. Providing a cost effective...
Resource Type:: Masters Thesis

Alaska Native Education : Sheldon Jackson to Paul Jensen 1884-1984

Creator:: Martain, Jacqueline
Abstract:: This thesis will look at Paul Jensen while he was an education professor at Western Oregon State College in Monmouth, Oregon, and his role in Alaska Native education while working with the Bureau of Indian Affairs. Dr. Jensen's work coincided with the last twenty-five years of Bureau of Indian Affairs...
Resource Type:: Masters Thesis

Public Participation in Urban Policy – Solution Papers Founded on Objectivity and Mutual Respectfulness

Creator:: Zarins, Eriks
Abstract:: In recent times, public policy debates in the United States have been very contentious and dysfunctional. To help improve this situation, a multi-discipline research effort was conducted to look at "solution papers" as a form of public participation. Specifically, the roles of objectivity and mutual respectfulness were under consideration. Foundational...
Resource Type:: Masters Thesis

Modeling animal movement to manage landscapes

Creator:: Larson-Praplan, Stephanie
Abstract:: Managing rangelands with livestock grazing is a tool that can be applied to obtain vegetation management objectives. Animals utilize available resources, which vary in quantity and quality, across the landscape. Their movements are adjusted to the spatial and temporal heterogeneity of resource distribution. Controlling livestock distribution is fundamental to economically...
Resource Type:: Dissertation

Factors associated with school teachers' attitudes toward HIV prevention education in Lusaka, Zambia

Creator:: Henning, Margaret Jo
Abstract:: In Zambia, there are approximately 920,000 people living with HIV/AIDS. Children are often referred to as a "window of hope" due to a low HIV/AIDS prevalence rate (UNAIDS/WHO, 2006). With growing numbers of infections and an increased strain on the social and economic structure due to HIV/AIDS there is a...
Resource Type:: Dissertation

Zooplankton of the Galapagos Islands

Creator:: Figueroa, Diego
Abstract:: The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish the distribution and community structure of zooplankton in the Archipelago. I collected zooplankton samples by vertical tows over the Galapagos...
Resource Type:: Dissertation

A hierarchical neuro-evolutionary approach to small quadrotor control

Creator:: Shepherd, Jack F., III
Abstract:: Quadrotors are unique among Micro Aerial Vehicles in providing excellent maneuverability (as opposed to winged flight),while maintaing a simple mechanical construction (as opposed to helicopters). This mechanical simplicity comes at a cost of increased controller complexity. Quadrotors are inherently unstable, in the sense that they are essentially unflyable by a...
Resource Type:: Masters Thesis

Numerical simulation of cavitating bubble-laden turbulent flows

Creator:: Shams Sobhani, Ehsan
Abstract:: Many engineering devices and propulsion systems suffer from undesirable effects of cavitation; such as degradation in the efficiency of pumps and turbines, generation of noise and vibration on ship propeller, increased drag and erosion of propeller blade, etc. In spite of decades of research on this problem, detailed study of...
Resource Type:: Dissertation

Reduced order modeling of legged locomotion in the horizontal plane

Creator:: Wickramasuriya, Gamika Arun
Abstract:: Sprawled-posture insects exhibit a remarkable ability to rapidly run in a stable manner over complex terrain, a feat that has yet to be equaled by man-made legged robots. Recent experimental results suggest that these insects may employ a hierarchical control structure, in which locomotion performance emerges from a combination of...
Resource Type:: Dissertation

Hartree-Fock electronic structure calculations forfree atoms and immersed atoms in an electron gas

Creator:: Walsh, Kenneth Charles
Abstract:: Electronic structure calculations for free and immersed atoms are performed in the context of unrestricted Hartree-Fock Theory. Spherical symmetry is broken, lifting de-generacies in electronic conﬁgurations involving the magnetic quantum number m. Basis sets, produced from density functional theory, are then explored for completeness. Com-parison to spectroscopic data is done...
Resource Type:: Dissertation

Essays in semiparametric econometrics

Creator:: Livingston, Olga Voyteshenko
Abstract:: Two essays are focused on semiparametric econometric methods. The first essay investigates applicability of the smooth back tting estimator (SBE) to statistical analysis of residential energy consumption. The second essay attempts to incorporate additivity restrictions into semiparametric stochastic frontier estimation. The procedure described in the first study is used to...
Resource Type:: Dissertation

Anthropological case studies of religious syncretism in Bolivia

Creator:: Lord, Jonathan
Abstract:: Religious histories have always appropriated pre-existing symbol systems of religion into newer forms, often with the goal in mind to acculturate a population into a new cultural setting to reach a desired status quo of society. The problem with acculturation theory is that it is filled with teleological and quantitative...
Resource Type:: Masters Thesis

Diurnal wind-driven processes on the northern Monterey Bay inner shelf

Creator:: Suanda, Sutara H.
Abstract:: In the summer of 2007, a biophysical experiment was conducted to identify physical processes that determine the delivery of invertebrate larvae and juvenile rockfish to rocky intertidal and kelp forest communities in northern Monterey Bay, California. The experiment was sponsored by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO)...
Resource Type:: Masters Thesis

Investigating the effects of temperature on secondary metabolism in Vitis vinifera L. cv. merlot berries

Creator:: Cohen, Seth D.
Abstract:: Grapes (e.g. Vitis vinifera L.) are one of the more important fruit crops from an economic standpoint with world market values over 550 million US dollars in 2007 and 2008, second to apples (United States Department of Agriculture). While a satisfactory level of ripeness is of primary concern, the quality...
Resource Type:: Dissertation

Growth, residence, and movement of juvenile Chinook salmon within restored and reference estuarine marsh channels in Salmon River, Oregon

Creator:: Hering, David K.
Abstract:: Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes for agricultural and urban development may have contributed to a decline in salmon abundance in the Pacific Northwest, prompting efforts to...
Resource Type:: Masters Thesis

Histological examination of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues

Creator:: Botts, Molly M.
Abstract:: Colonization of N. densiflorus tissues by P. ramorum is not well understood. The pathogen is able to colonize nearly all tissues of this host but it is unclear how a tree is ultimately killed. Because this is such a destructive invasive pathogen, it is important to investigate its pathogenic strategy....
Resource Type:: Masters Thesis

Development of organocatalyzed, intramolecular heteroatom Michael addition and application towards alkaloid synthesis

Creator:: Carlson, Erik
Abstract:: Effective methods for the enantiopure formation of substituted piperidine rings are significantly important due to their presence in alkaloid products. A valuable method to form these ring systems would be via an intramolecular heteroatom Michael addition from the corresponding enone or enal. Described herein is a methodolgy that has been...
Resource Type:: Masters Thesis

The adsorption of human recombinant factor VIII in the presence of the nonionic triblock surfactant Pluronic® F-68 at the air-water interface

Creator:: Alkhatib, Aveen K.
Abstract:: The adsorption behavior of a human recombinant Factor VIII (rFVIII) in the presence of the nonionic, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock surfactant Pluronic® F-68 was evaluated by dynamic air-water tensiometry. Surface tension kinetics were recorded for F-68 in the absence of protein at concentrations ranging from 0 to 10,000...
Resource Type:: Masters Thesis

Efficient classification for longitudinal data

Creator:: Wang, Xianlong
Abstract:: We propose a new classification method for longitudinal data based on a semiparametric approach. Our approach builds a classifier by taking advantage of modeling information between response and covariates for each class, and assigns a new subject to the class with the smallest quadratic distance. This enables one to overcome...
Resource Type:: Dissertation

Biomarkers of oxidative stress and DNA damage in agricultural workers

Creator:: Muniz, Juan Fermin
Abstract:: Pesticides are among the most pervasive environmental contaminants and they are an important potential risk for human health. Agricultural workers are constantly exposed to pesticide spray, drift and residues in the soil and foliage. Many agricultural pesticides are readily absorbed by the body, through contact with the skin, the respiratory...
Resource Type:: Dissertation

The potential of using log biometrics to track sawmill flow

Creator:: Peterson, Matthew G.
Abstract:: We studied the feasibility of using end-grain characteristics to match individual boards and cants back to their parent Douglas-fir (Pseudotsuga menziesii) logs. After reviewing marking/reading and biometric automated identification systems, we focused on end-grain biometrics because they appear to have the most promise for sawmills. Biometric identification requires that every...
Resource Type:: Masters Thesis

The role of copper and its chelation by tetrathiomolybdate in inflammation and atherosclerosis

Creator:: Wei, Hao
Abstract:: Endothelial activation with increased expression of cellular adhesion molecules, chemokines and pro-inflammatory cytokines critically contributes to vascular inflammation and the initiation and progression of atherosclerosis. By affecting redox-sensitive cell signaling pathways and transcription factors, redox-active transition metal ions, such as copper and iron, may play an important role in these...
Resource Type:: Dissertation

Enhancing hydrogen production in microbial electrolysis cells through development of platinum-free cathode and improvement of reactor design

Creator:: Hu, Hongqiang
Abstract:: Microbial electrolysis provides a new approach for hydrogen generation from renewable biomass. At current stage, the most likely limiting factors for successful scale up of this technology are the large internal resistance and high fabrication cost. This dissertation presents an attempt to overcome these limitations by investigating novel microbial electrolysis...
Resource Type:: Dissertation

Radically reframing environmental problems : The Salmon 2100 case study

Creator:: Lane, David Earl
Abstract:: There are typically two responses to the complex environmental problems of our time: 1) doom and gloom and 2) optimism. There is a lot of doom and gloom in the environmental literature. This literature warns that the future portends danger for humans and their life support systems. But when one...
Resource Type:: Dissertation

Opportunities and limitations for community forest enterprises : case of TIP Muebles, Oaxaca, Mexico.

Creator:: Villavicencio Valdez, Gabriela Valeria
Abstract:: The fact that 80 percent of Mexican forestlands are under common ownership impacts the competitiveness of the forest products industry and forest sustainability. Community forest enterprises (CFE) are a heterogeneous group of forest industries managed by indigenous and local communities for livelihood and profit. Many CFEs face inner competitiveness problems,...
Resource Type:: Masters Thesis

Aquatic insect adaptations to different flow regimes

Creator:: Yamamuro, Asako Melody
Abstract:: My thesis explored the effects of environmental variability on population dynamics and community composition of aquatic insects. Environmental variability in the form of flow regime in streams can limit the distribution and life-history traits of aquatic insects. I used tributaries to the McKenzie River in Oregon with dramatically different flow...
Resource Type:: Dissertation

The Costa Rica Dome : a study of physics, zooplankton and blue whales

Creator:: Matteson, Robyn S.
Abstract:: At the Costa Rica Dome (CRD), upwelling associated with cyclonic circulation and the presence of a shallow thermocline support a highly productive biological habitat, exploited by marine fauna at several trophic levels. During January 2008, a cruise to the CRD by the R/V Pacific Storm was conducted to relocate blue...
Resource Type:: Masters Thesis

Epichloë typhina (fungus) - Botanophila lobata (fly) interaction : an invasive "pollinator" system in its introduced range in western Oregon

Creator:: Kaser, Joseph M.
Abstract:: Epichloë typhina (Ascomycetes: Clavicipitaceae) is an endophytic fungus that infects perennial Pooid grasses and is the causal agent of choke disease. It is endemic to Europe and was inadvertently introduced into orchardgrass seed production fields in western Oregon. Choke disease, which was first recorded in Oregon in 1996, currently infects...
Resource Type:: Masters Thesis

Bioenergetics individual based model explorations of juvenile coho salmon growth during their first summer on the Oregon shelf

Creator:: Reser, Brendan Alexander
Abstract:: Salmon survival and eventual recruitment success have long been thought to be determined within the first summer following ocean migration. Juvenile growth during this period is largely influenced by ocean conditions such as temperature, prey availability, abundance, and quality. Shifts in these conditions due to climatic perturbations are particularly prevalent...
Resource Type:: Masters Thesis

Potential barriers to movements and habitat selection of pygmy rabbits (Brachylagus idahoensis) after experimental translocation

Creator:: Lawes, Timothy J. (Timothy James)
Abstract:: I assessed potential barriers to dispersal using homing tendency and investigated the movements and settlement site selection of pygmy rabbits (Brachylagus idahoensis) after short distance translocations in southeastern Oregon from June – December 2008. I captured, radio marked, and translocated 59 pygmy rabbits 1-2 km across landscapes with (1) continuous...
Resource Type:: Masters Thesis

Susceptibility of juvenile salmonids to avian predation : Are Caspian terns and double-crested cormorants only taking the sick and injured?

Creator:: Hostetter, Nathan J.
Abstract:: The ability to non-destructively assess fish condition and subsequently track fish behavior and survival can be vital in understanding natural and anthropogenic stressors and sources of mortality, especially in populations of fish listed as threatened or endangered. I investigated the use of a quick, non-lethal, external examination technique to assess...
Resource Type:: Masters Thesis

On error bounds for linear feature extraction

Creator:: Thangavelu, Madan Kumar
Abstract:: Linear transformation for dimension reduction is a well established problem in the field of machine learning. Due to the numerous observability of parameters and data, processing of the data in its raw form is computationally complex and difficult to visualize. Dimension reduction by means of feature extraction offers a strong...
Resource Type:: Masters Thesis

Analytical determination of copper speciation in Oregon highway runoff

Creator:: Sprick, Matthew S.
Abstract:: Low concentrations of dissolved copper have been shown to adversely affect the olfactory system of endangered salmonids, impairing their ability to avoid predators and likely increasing predation. It is believed that only the free ionic (Cu2+ free) and weakly complexed forms are bioavailable to organisms; these forms typically account for...
Resource Type:: Masters Thesis

New acoustic emission applications in civil engineering

Creator:: Schumacher, Thomas
Abstract:: Non-destructive testing methods and applications have become of increasing interest due to the worldwide aging and deteriorating infrastructure network. In the field of Civil Engineering, bridges and bridge components as well as non-structural elements such as roadway pavements for example, are affected. In particular, the Acoustic Emission (AE) technique offers...
Resource Type:: Dissertation

The effect of coagulation conditions on floc size distribution and morphology : implications for downstream treatment processes

Creator:: Maguire, Ian R.
Abstract:: Coagulation and flocculation are commonly used in drinking water treatment as a means of destabilizing and aggregating particles and promoting adsorption of dissolved organic carbon (DOC). In practice, jar tests are used to determine optimal conditions for the removal of turbidity and DOC. However, beyond the inferences that can be...
Resource Type:: Masters Thesis

Mass spectrometry-based identification and characterization of protein and peptide adducts of lipoxidation-derived aldehydes

Creator:: Chavez, Juan D.
Abstract:: Oxidative stress is recognized as an important underlying factor in the pathogenesis of many degenerative diseases as well as normal senescence. The free radicals, reactive oxygen species (ROS) and electrophiles produced during oxidative stress are capable of modifying nucleic acids, lipids and proteins. There are a variety of oxidative modifications...
Resource Type:: Dissertation

Monitoring river restoration using fiber optic temperature measurements in a modeling framework

Creator:: Huff, Julie A.
Abstract:: The Middle Fork of the John Day River (MFJD) in Northeastern Oregon contains important spawning grounds for spring Chinook and summer steelhead of the Columbia River Basin. In the summer of 2008 phase one of a river restoration project was completed which included the addition of engineered log jams (ELJs)...
Resource Type:: Masters Thesis

Essays in applied economics

Creator:: Nag, Sharmistha
Abstract:: My dissertation concerns two separate issues. The first issue is examined in Essay One, and the second issue is examined in Essays Two and Three. The first essay develops an economic model of the determination of the rental rate of leased farmland in the United States. Particular attention is placed...
Resource Type:: Dissertation

Nitrogen isotopes in a global ocean biogeochemical model : constraints on the coupling between denitrification and nitrogen fixation

Creator:: Somes, Christopher J.
Abstract:: We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
Resource Type:: Masters Thesis

Understanding and supporting end-user debugging strategies

Creator:: Grigoreanu, Valentina I.
Abstract:: End users' programs are fraught with errors, costing companies millions of dollars. One reason may be that researchers and tool designers have not yet focused on end-user debugging strategies. To investigate this possibility, this dissertation presents eight empirical studies and a new strategy-based end-user debugging tool for Excel, called StratCel....
Resource Type:: Dissertation

Mass transfer of urea, creatinine and vitamin B-12 in a microchannel based membrane separation unit

Creator:: Warner-Tuhy, Alana
Abstract:: Micro energy and chemical systems (MECS) are microfluidic systems where energy and chemical processes can be intensified by decreasing the characteristic length. This project focused on bulk fluid processing using MECS technology to intensify the mass transport of a dialyzer. The objective of this project was to design a model...
Resource Type:: Masters Thesis

Experimental approach for the determination of lignin modification by manganese peroxidase

Creator:: Goby, Jeffrey D.
Abstract:: Degradation of lignin to simpler compounds is desirable for removing residual lignin during paper manufacture and accessing biomass carbohydrates for biofuel production, among other purposes. Lignin transformation using enzymes found in white rot fungi, some of nature's most efficient lignin-degrading organisms, offers a more environmentally benign, selective, and possibly less...
Resource Type:: Masters Thesis

Bridging differences : Saudi Arabian students reflect on their educational experiences and share success strategies

Creator:: Shaw, Donna L. (Donna Laible)
Abstract:: This study examines the U.S. educational experiences of Saudi Arabian students. Using qualitative case study and photo-elicitation research methods, this study conducted multiple interviews with 25 Saudi students and explored their perceptions of their American learning environment, how it differed from Saudi Arabia, and the strategies they developed to successfully...
Resource Type:: Dissertation

Impact of parameter variability on the food process engineering calculations required for safety, quality and shelf-life estimations

Creator:: Chotyakul, Nattaporn
Abstract:: Quantitative procedures were developed to determine the effect of variability in the model parameters required for the estimation of microbial shelflife and thermal processing time. Monte Carlo simulations combined with these predictive models were implemented in Microsoft Excel™. In the first study, predictive models were used for shelf-life predictions based...
Resource Type:: Masters Thesis

Tandem mass spectrometric analysis of protein and peptide adducts of lipid peroxidation-derived aldehydes

Creator:: Wu, Jianyong
Abstract:: The adduction of proteins and other biomolecules by electrophilic lipid peroxidation products such as 4-hydroxy-2-nonenal (HNE), 4-oxo-2-nonenal (ONE), malondialdehyde (MDA) or acrolein (ACR) is thought to be an initiating and/or propagating factor in the pathophysiology of several diseases such as atherosclerosis, diabetes, Alzheimer's, Parkinson's and other age-related disorders. The identification...
Resource Type:: Dissertation

Investigations of regulatory T cell induction by 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin during a graft-versus-host response

Creator:: Marshall, Nikki B.
Abstract:: The immune toxicity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been studied for over 35 years, but only recently has the profound immune suppression associated with TCDD exposure been linked to induction of regulatory T cells (Tregs). The effects of TCDD are mediated through binding the aryl hydrocarbon receptor (AhR), a ligand-activated transcription...
Resource Type:: Dissertation

π-line reconstruction formulas in computed tomography

Creator:: Hass, Ryan Andrew
Abstract:: X-ray computed tomography is a noninvasive imaging modality capable of reconstructing exact density values of 3D objects. Computed tomography machines are deployed across the world to provide doctors with an image that reveals more detail than a standard x-ray image. We investigate algorithms based on exact computed tomography reconstruction formulas...
Resource Type:: Dissertation

Evaluation of length distributions and growth variance to improve assessment of the loggerhead sea turtle, (Caretta caretta)

Creator:: Vaughan, Jason R.
Abstract:: Nest counts from the largest subpopulation of the loggerhead sea turtle (Caretta caretta) in the Atlantic, peninsular Florida, have been declining since 1998. Analyzing trends of nests and adult females is insufficient to determine the overall status of a sea turtle population, due to variation in nesting frequency and a...
Resource Type:: Masters Thesis

Duty-cycle controlled switched resistor techniques for continuously tunable, low-voltage circuits

Creator:: Kurahashi, Peter
Abstract:: A duty-cycle controlled switched resistor is a tunable resistive element that uses pulse width modulation as the method of tuning. This thesis will describe the operation of switched resistors and propose several circuit architectures that are well suited to the use of switched resistors. These architectures include filters, mixers, and...
Resource Type:: Dissertation

Study abroad and global competence : exemplary community college programs which foster elements of achievement

Creator:: Arden-Ogle, Ellen A.
Abstract:: The research‘s purpose was to examine how exemplary community college study abroad programs assisted student participants in acquiring global competence. Three research questions were explored: 1.What issues need to be anticipated when planning a study abroad program for community college students in order to effectively incorporate opportunities for students to...
Resource Type:: Dissertation

Forest-meadow dynamics in the central western Oregon Cascades : topographic, biotic,and environmental change effects

Creator:: Rice, Janine M.
Abstract:: Montane meadows comprise a small area of the predominantly forested landscape of the Oregon Cascade Range. Tree encroachment in the last century in these areas has threatened a loss of biodiversity and habitat. Climate change in the coming century may accelerate tree encroachment into meadows, and exacerbate biodiversity loss. Multiple...
Resource Type:: Dissertation

Temperature and infiltration characterization of a constructed wetland for wastewater treatment

Creator:: Gregory, Christopher T.
Abstract:: The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination System (NPDES) permit, the WWTP will require additional reduction of temperature and ammonia levels in the summer, especially in the critical month of...
Resource Type:: Masters Thesis

DNA-based identification of commercially important salmon and trout species (genera Oncorhynchus and Salmo) in North America

Creator:: Rasmussen, Rosalee S.
Abstract:: There are seven commercially important species of salmon and trout (genera Oncorhynchus and Salmo) in North America, many of which are closely related but command markedly different prices. The purpose of this research was to provide improved and novel methods for the detection of salmon species substitution on the commercial...
Resource Type:: Dissertation

Effect of constituent materials and curing methods on the abrasion resistance and durability of high performance concrete for pre-cast pre-stressed bridge deck slabs

Creator:: Keshari, Shweta
Abstract:: This thesis is the consequence of a research effort undertaken by the School of Civil and Construction Engineering at Oregon State University and funded by the Oregon Department of Transportation (ODOT) and the Federal Highway Administration (FHWA). The principal objective of the effort was to reduce the life cycle cost...
Resource Type:: Masters Thesis

Glacial to holocene watermass and continental weathering reconstructions from the Southeast Pacific

Creator:: Muratli, Jesse M.
Abstract:: Sediments of the central Chile margin record changes in ocean circulation and continental erosion associated with large–scale climate change. Here Antarctic– influenced Southern Ocean currents flow equatorward, forming a link between the high– and low–latitude oceans. Part of this link, Antarctic Intermediate Water, is an important conduit that ventilates South...
Resource Type:: Masters Thesis

Effect of cosputtered catalyst on growth and alignment of carbon nanotubes by plasma enhanced chemical vapor deposition

Creator:: Gunderson, Eric P.
Abstract:: The effect of cosputtered catalyst on growth and alignment of carbon nanotubes (CNTs) grown by plasma enhanced chemical vapor deposition (PECVD) was investigated. Aligned CNTs were observed using a cosputtered catalytic metal deposited directly on boro-aluminosilicate glass. Catalytic metal alloys were sputtered directly onto the substrate using magnetron sputtering. Deposition...
Resource Type:: Masters Thesis

Preschooler's perceptions of a patio garden

Creator:: Upington, Deborah A.
Abstract:: This study sought to fill a void in research literature supporting Attention Restoration Theory (ART) and the beneficial effects of exposure to natural, green spaces. The literature predominantly discusses studies with adult and older child participants, finding that exposure to natural environments often produces an attention-restoring effect. ART has been...
Resource Type:: Masters Thesis

Distinguishing biological and physical controls on soil respiration

Creator:: Phillips, Claire L.
Abstract:: Soil respiration, or the combined CO₂ emissions from roots and soil microorganisms, constitutes one of the largest losses of carbon (C) from terrestrial ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate quality, have been known for some time. Nevertheless, correlations between these drivers and...
Resource Type:: Dissertation

Environmental variability and system heterogeneity in terrestrial biogeochemical models

Creator:: Sierra, Carlos Alberto
Abstract:: Ecosystems are highly heterogeneous systems subjected to important levels of environmental variability; however, it is common in terrestrial biogeochemical models to assume homogeneous properties of the elements of the system or constant environmental conditions. For some processes, heterogeneity in these models is treated very simplistically, but there is not much...
Resource Type:: Dissertation

Dynamics of a long-lived magmatic system as indicated by variations in amphibole composition and textures in dacites erupted over 11 M.y. at the Aucanquilcha Volcanic Cluster, Central Andes, Chile

Creator:: Giles, Denise E. L.
Abstract:: The Aucanquilcha Volcanic Cluster (AVC) is the erupted part of a magmatic system with a complex and long-lived history. The AVC lies at 21°S in the high Andes and is built on thick continental crust. The thick crust in the area combined with the prolonged magmatic activity make it an...
Resource Type:: Masters Thesis

The effect of youth participatory evaluation and youth community action training on positive youth development

Creator:: White, David J. (David Joseph)
Abstract:: The bi-directional relationships within the personal and contextual environments of adolescents are critical to the development of adolescents and their transition into adulthood. Opportunities for youth to participate in and provide leadership in meaningful programs, gain life skills, and interact with adults in sustained relationships are key features leading to...
Resource Type:: Dissertation

Observations on the evolution of shoaling nonlinear internal waves in Massachusetts Bay using shipboard X-band radar

Creator:: Nelson, Brian G.
Abstract:: During four cruises in July and September of 2008 and 2009, the shipboard X-band radar was tuned to detect the modulated bands of surface roughness caused by converging and diverging currents associated with high-frequency nonlinear internal wave (NLIW) packets. The data collected was used to quantify the propagation direction (ϴp),...
Resource Type:: Masters Thesis

Beginning the year in a fifth-grade reform-based mathematics classroom : A case study of the development of norms

Creator:: Cheval, Kathryn Meador
Abstract:: The purpose of this qualitative case study was to investigate the development of social norms in a fifth-grade reform-based mathematics classroom through a close examination of one teacher's actions during the first three weeks of school. This study offers insights into the following research questions: 1) How does an elementary...
Resource Type:: Dissertation

Emotional effect of curvilinear vs. rectilinear forms of furniture in interior settings

Creator:: Dazkir, Sibel Seda
Abstract:: This study focused on people’s emotional responses to curvilinear and rectilinear lines in interior environments. Emotional reactions towards simulated interior settings were tested by having subjects complete an online survey. The survey tested respondents’ emotional reactions triggered by different forms of furniture. The survey included questions about six simulated interior...
Resource Type:: Masters Thesis

Design, analysis and evaluation of bridge superstructures for live loads

Creator:: Turan, O. Tugrul
Abstract:: Due to age, original design that is deficient by modern standards, inadequate maintenance, environmental conditions, and increasing loads, large numbers of bridges in United States and elsewhere are classified as deficient and in need of rehabilitation or replacement. According to a national bridge inventory established by the Federal Highway Administration,...
Resource Type:: Dissertation

Toward end-user debugging of machine-learned programs

Creator:: Kulesza, Todd
Abstract:: The results of a machine learning from user behavior can be thought of as a program, and like all programs, it may need to be debugged. Providing ways for the user to debug it matters because without the ability to fix errors, users may find that the learned program’s errors...
Resource Type:: Masters Thesis

Influence of stocking density on grazing beef cattle performance, diet composition foraging efficiency, and diet quality on a late-spring early-summer native bunchgrass prairie

Creator:: Wyffels, Samuel A.
Abstract:: This study evaluated the influence of cattle stocking density on botanical composition of diet, diet preference, and cattle performance on the Zumwalt Prairie in Northeastern Oregon. In each of two years, 192 cow-calf pairs (549.27 kg, BCS = 4.89) and 48 yearling heifers (383.34 kg, BCS = 5.02) were stratified...
Resource Type:: Masters Thesis

Toward a more ethical engineering : four habits of highly ethical engineering practice

Creator:: Sugie, Masayuki Luke
Abstract:: In this thesis, I conduct an analysis of paradigmatic background assumptions deployed in engineering decision-making processes, in order to understand how these assumptions, operating tacitly and in tension with each other, contribute to decisions that are ethically less effective and less substantial than they would otherwise be. I do so...
Resource Type:: Masters Thesis

Integrating restoration and ecologically based weed management practices for invasive knotweed control

Creator:: Rudenko, Melody
Abstract:: Japanese knotweed is an invasive perennial shrub that dominates riparian ecosystems. Effective management techniques are currently limited to repeated annual herbicide applications and there is little science-based information about which control tactics result in the greatest management success. Restoration of invaded sites to a functioning riparian plant community is needed...
Resource Type:: Masters Thesis

Statistical analysis and speciation modeling of copper in Oregon highway runoff

Creator:: Bloomquist, Don J.
Abstract:: Low levels of copper have been shown to impair the olfactory system of threatened and endangered (T&E) salmon, decreasing their predator avoidance behavior and likely increasing mortality. However, only dissolved copper (dissCu) present as the cupric ion (Cu2+) and weakly complexed species are truly bioavailable. Previous studies indicate the vast...
Resource Type:: Masters Thesis

Learning based methods applied to the MAV control problem

Creator:: Salichon, Max
Abstract:: This thesis addresses Micro Aerial Vehicle (MAV) control by leveraging learning based techniques to improve robustness of the control system. Applying classical control methods to MAVs is a difficult process due to the complexity of the control laws with fast and highly non-linear dynamics. These methods are mostly based on...
Resource Type:: Dissertation

Design techniques for wideband low-power Delta-Sigma analog-to-digital converters

Creator:: Wang, Yan
Abstract:: Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations...
Resource Type:: Dissertation

Scaling multiagent reinforcement learning

Creator:: Proper, Scott
Abstract:: Reinforcement learning in real-world domains suffers from three curses of dimensionality: explosions in state and action spaces, and high stochasticity or "outcome space" explosion. Multiagent domains are particularly susceptible to these problems. This thesis describes ways to mitigate these curses in several different multiagent domains, including real-time delivery of products...
Resource Type:: Dissertation

A self-calibrated, reconfigurable RF LNA

Creator:: Jayaraman, Karthik
Abstract:: Modern wireless System-on-Chips (SoCs), such as mobile handsets, sensor networks, and mm-wave systems, integrate an entire RF system on a single CMOS chip. Such highly complex systems require significant on-chip digital signal processing to help improve the performance of highly sensitive analog/RF components. The IC market being competitive, the ability...
Resource Type:: Masters Thesis

A recurrent neural network implementation using the graphics processing unit

Creator:: Moore, Christopher
Abstract:: We took the back-propagation algorithms of Werbos for recurrent and feed-forward neural networks and implemented them on machines with graphics processing units (GPU). The parallelism of these units gave our implementations a 10 to 100 fold increase in speed. For nets with less than 20 neurons the machine performed faster...
Resource Type:: Masters Thesis

Monte-Carlo planning for probabilistic domains

Creator:: Bjarnason, Ronald V.
Abstract:: This thesis presents a progression of novel planning algorithms that culminates in a new family of diverse Monte-Carlo methods for probabilistic planning domains. We provide a proof for performance guarantees and analyze how these algorithms can resolve some of the shortcomings of traditional probabilistic planning methods. The direct policy search...
Resource Type:: Dissertation

Mathematical approaches to the physics of mesoscale oceanography

Creator:: Early, Jeffrey J.
Abstract:: The long-term evolution of Gaussian eddies is studied in an equivalent barotropic model using both linear and nonlinear quasi-geostrophic theory in an attempt to understand westward propagating satellite altimetry tracked mesoscale eddies. By examining both individual eddies and a large basin seeded with eddies, it is shown that long term...
Resource Type:: Dissertation

Weighing in on NBC's "The Biggest Loser" : surveillance medicine, self-concept, and gender on the scale

Creator:: Readdy, Ryan T.
Abstract:: The current appeal of reality television is undeniable, with the specific genre of makeover television having special nationalistic and moral appeal in the United States. Previous analyses of NBC's weight-loss makeover show The Biggest Loser suggest that the program is inherently problematic because of its ingrained fat bias and unethical...
Resource Type:: Dissertation

In vitro and in vivo approaches for the functional characterization of the scaffold protein, GRASP

Creator:: Venkataraman, Anand
Abstract:: Studies using the pluripotent embryonic carcinoma cell line, P19, as a retinoic acid (RA)-responsive model system have been instrumental towards our understanding of the RA-dependent signaling pathways in development and homeostasis. Grp1-associated scaffold protein (GRASP; also known as Tamalin) was first identified by our group, as a gene robustly induced...
Resource Type:: Dissertation

Functional polymers and proteins at interfaces

Creator:: Schilke, Karl F.
Abstract:: Functional polymers and proteins at interfaces and surfaces are of fundamental importance for biomaterials, biocatalysis and microreactor applications. Candida antarctica lipase B immobilized on poly-DL-tryptophan tethers showed 30x higher specific activity in aqueous and non-aqueous media than the same enzyme adsorbed or covalently bound directly to the surface. An excess...
Resource Type:: Dissertation

Development of an improved system for Oregon to accurately quantify dense-graded hot mix asphalt pavement density

Creator:: Darra, Suraj
Abstract:: The Oregon Department of Transportation (ODOT) standard specifications require a minimum density for the construction of dense-graded hot mix asphalt (HMA) pavements. Currently, the standard specifications call for density measurements for quality control (QC) and quality assurance (QA) testing to be made using nuclear density gauges that are calibrated using...
Resource Type:: Masters Thesis

Designers from United States, Taiwan and South Korea develop hanbok inspired apparel: a cultural comparison of design elements

Creator:: Song, Sarah S.
Abstract:: The purpose of this study was to determine differences in the way a designer designs because of his or her cultural background. For example, would a designer from the US design with the same components of design in mind as someone from another country? The objective was not to explore...
Resource Type:: Masters Thesis

Studies to inform a visual language for authoring interactive exercise prescriptions

Creator:: Dodge, Jonathan E.
Abstract:: Communicating dynamic motion content, such as exercise, with a static medium, such as paper, is diﬃcult. The technology exists for presenting 3D animated exercise content to patients; however, the tools for allowing exercise domain experts to eﬀectively author the content do not exist. We conducted two formative studies with exercise...
Resource Type:: Masters Thesis

A new method of making particleboard with a formaldehyde-free soy-based adhesive

Creator:: Prasittisopin, Lapyote
Abstract:: Particleboard is widely used for making bookshelf, furniture, cabinets and many other interior products. At present, particleboard is mainly produced with wood particles and urea-formaldehyde (UF) resins. The emission of carcinogenic formaldehyde in the production and use of particleboard has generated an urgent need for development of a formaldehyde-free wood...
Resource Type:: Masters Thesis

Radiation safety practices in interventional radiology : the importance of oversight

Creator:: Lally, Mary T.
Abstract:: It is widely recognized that the risks associated to both patients and medical personnel during therapeutic interventional procedures are greater than for other diagnostic studies due to the increased number, and complexity of the examinations resulting in increased radiation exposure. This report documents the practices of seven interventional radiologists at...
Resource Type:: Masters Thesis

Microhabitat associations and behavioral dynamics of co-occurring native Pacifastacus leniusculus and invasive Procambarus clarkii crayfish in Oregon's southern Willamette Valley

Creator:: Hanshew, Brett Alan
Abstract:: Biological invasions are the second largest threat to biodiversity following habitat loss, and studying invasions has been a focus of ecological the past two decades. Despite the intense research, many basic questions remain empirically unanswered, particularly in the realm of behavior. The purpose of this research was to explore the...
Resource Type:: Masters Thesis

Design, construction, and analysis of a skin contamination dosimeter

Creator:: Cazalas, Edward J.
Abstract:: International recommendations provided by the International Commission on Radiation Protection (ICRP), as well as national regulations, set by the U.S. Nuclear Regulatory Commission (NRC), state that the exposure of skin to highly concentrated radioactive sources should be monitored at specified depths in skin and kept below specific dose equivalence levels....
Resource Type:: Masters Thesis

The meaning of persistence for African American femalesattending urban community colleges

Creator:: Glavan, John
Abstract:: The purposes of this study were to examine the experiences of African American female students attending urban community colleges, to gain further understanding of how they interpret the meaning of persistence, and to identify the factors that affect their persistence. African American women attending community college in Los Angeles were...
Resource Type:: Dissertation

Teacher argumentation in the secondary science classroom : images of two modes of scientific inquiry

Creator:: Gray, Ron E.
Abstract:: The purpose of this exploratory study was to examine scientific arguments constructed by secondary science teachers during instruction. The analysis focused on how arguments constructed by teachers differed based on the mode of inquiry underlying the topic. Specifically, how did the structure and content of arguments differ between experimentally and...
Resource Type:: Dissertation

Provenance, lifespan, and phylogeny : testing a conceptual framework for plant community management

Creator:: Benfield, Cara D.
Abstract:: Successful conservation management requires an understanding of how species respond to intervention. Native and exotic species may respond differently to management interventions due to differences arising directly from their native or exotic origin (i.e., provenance) or from differences in life-history or phylogenetic lineage that are associated with provenance. Thus, selection...
Resource Type:: Masters Thesis

Prediction of mass transfer performance of microchannel dialyzersusing deconvolution of impulse-response experiments

Creator:: Anderson, Eric K.
Abstract:: The parallel implementation of a large number of functional units is necessary for any industrial scale microfluidic process. The concept of a 'numbering up' strategy where a single highly optimized functional unit that has a low individual production is replicated a large number of times to create a device that...
Resource Type:: Masters Thesis

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