Under researched somatosensory contributions to postural stability, in addition to high incident rates of foot injury in the physically active population, lead to two investigative studies. An initial research study compared variables of two postural stability assessment devices to determine reliability of outcome measures and commonality of outcome measures to...
A study regarding steady-state conditions in boiling water
reactors was conducted in order to provide consistent initial conditions
for transient analysis using the computer simulation code,
RETRAN. Consistent steady states were generated with the RETRAN
model of the system by first establishing a reference state, and then
obtaining other steady...
A method is presented for appraising the hazards to nuclear
power plants from missiles from surface traffic accident explosions.
Due to the infrequency with which surface traffic accident explosions
occur and the poor records kept concerning them, a probabilistic
method is chosen to investigate the overall hazards potential to
nuclear...
The limiting conditions of operation with regard to system stability for BWRs are presently set using computer models which employ conservative assumptions regarding the mechanisms which affect stability. Development of BWR models using "best estimate" codes, such as RETRAN, may allow more exact stability limits to be determined and precise...
The goal of this study is the modeling of a postulated break
of the steam line at the containment penetration of the Trojan
Nuclear Plant which is owned and operated by Portland General
Electric. To perform this modeling, the RETRAN computer code
package was utilized. RETRAN is designed to provide...
A detailed formulation of the momentum equation
including the Baroczy model for two phase friction is
presented in this thesis. Numerical techniques for solving
this equation along with the remainder of the describing
equations are also presented. This model has been
incorporated into an existing thermal hydraulic code for
simulating...
A vital safety concern in the analysis of nuclear power reactors
is the thermal hydraulic behavior of the reactor coolant system
under steady state and transient conditions. The goal of this
study has been to develop an appropriate model for the U-tube type
steam generators in a typical pressurized water...
Within The Lamplighter, a novel written in 1854, Maria
Susanna Cummins defines a version of the sentimental novel
that significantly differs from the prescriptive analysis
male critics have offered for the genre. This thesis
argues that feminist theory and recent rhetorical theory
have caused a critical paradigm shift that has...
Evaporation synergy is a phenomenon that occurs between different classes of soil and allows for a greater amount/quantity of soil water evaporation. 20 of the 66 soil texture class combinations have been shown to exhibit evaporation synergy (Fisher, 2012), however the impact of column width on the functionality of this...
Pseudo-Nitzschia (P/N) is a species of naturally occurring phytoplankton that contributes to harmful algal blooms (HABs) in the California Current System (CCS). P/N can produce domoic acid (DA), a toxin which accumulates in organisms that consume phytoplankton, leading to amnesiac shellfish poisoning in higher trophic levels. Thus DA can negatively...
It is known that soil biota affects water dynamics through various complex mechanisms. The impact on retention by soil biota are due to a combination of changes to pore geometry, pore clogging by biofilms, biofilms that serve to connect thin water films across many pores as the soil dries, and...
Creeping bentgrass (Agrostis stolonifera L.) is an outcrossing, small- seeded, perennial grass that can establish outside of cultivation and has several compatible relatives. Glyphosate is a nonselective, broad spectrum, herbicide. Transgenic glyphosate-resistant (GR) creeping bentgrass (GRCB) was developed by The Scotts Company and Monsanto, but is still under USDA-APHIS regulated...
The extent of agricultural drainage has created concern for its potential undesirable effects on surface water quality. Land applications of liquid manure on tile drain fields have the potential to transport solutes and bacteria to the drains following precipitation or irrigation events and many times are directly sent to a...
Open-field burning has been an effective, economical, and widespread method of post-harvest residue management in creeping red fescue seed production in the Willamette Valley since the late 1940s. However, the use of field burning has been legislatively restricted due to air quality and safety issues. The foliar-applied plant growth regulator...
The regulation of behavior is a major issue in early childhood development, with important implications for children’s adaptive and maladaptive developmental outcomes. Emerging research suggests that the degree of successful self-regulation depends upon the efficiency of the child’s attentional system and that the ability to focus and sustain attention supports...
Neurofibromatosis Type 2 (NF2) is a genetic tumor disorder caused by mutations that inactivate the gene coding for the Merlin tumor suppressor. Patients with NF2 develop multiple tumors throughout the nervous system, mainly schwannomas, for which there is no cure or effective treatment. In NF2, redox signaling and oxidative stress...
The kinetics of physical and chemical processes controlling the precipitation of iron oxide minerals in unsaturated media were investigated in this study. The characteristic morphology, mineralogy, and chemistry of iron oxides were also explored. Laboratory column experiments using fine and coarse grades of silica sand were conducted to compare the...
Prospective teachers enter teacher education programs with previously
formed conceptions of geometry and its teaching. These conceptions help
them make sense of new information about teaching, their roles as teachers,
and their translation of mathematics into learning activities. The purpose of
this study was to investigate the relationships among preservice...
Harmful algal blooms (HABs) are a problem for coastal communities, the fishing industry, and coastal organisms. Pseudo-nitzschia spp. is a regularly occurring diatom in Oregon’s coastal waters. At times, Pseudo-nitzschia spp. can facultatively produce domoic acid, a neurotoxin that can bioaccumulate in the food chain. While regular shore-based sampling provides...
Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
This work is concerned with determining whether nicotine has a role in promoting oxidative damage in human tissue, particularly in lung tissue. This follows from recent reports of a novel lung disease found in some E-cigarette users, characterized by oxidative damage and elevated levels of neutrophils (termed “vaping disease”). It...
Many species of rodents and insectivores live in subterranean burrows in soils throughout the world. The soil surface perforations of burrow entrances are often connected to complex, subsurface tunnel networks. Burrow entrances and associated subsurface tunnel networks represent a link between surface and subsurface ecological function. Anecdotal observations of surface-water...
Evaporation from bare soil was investigated using a numeric model In one set of simulations, texture and evaporative demand were analyzed as they impacted short and long term evaporation. The effect of these factors on water redistribution was also analyzed. A second set of simulations was run to determine the...
Dynamic seascapes, which are classified using a combination of remotely sensed data and model output, represent a potential tool for dynamic ecosystem-based management in marine systems. This work explores the utility of seascape classification in the context of marine resource management by examining two case studies: one involving biological relationships...
The spring bloom is a key oceanic phenomenon in the Northern Gulf of Alaska (NGA), where it supports the regional ecosystem, fisheries, and CO2 sequestration. Despite its significance, mechanisms that trigger NGA blooms are still debated, largely due to a lack of sufficient data from late winter through spring. New...
Soil solarization trials were conducted during the growing seasons of 2016-2018 with the purpose of determining if solarization was an effective pre-planting soil disinfestation technique for tree nurseries in the Pacific Northwest. A large data set was collected on soil properties and biological indicators from 5 interdisciplinary experiments. This thesis...
Aquifer recharge is generally driven by fluids that move from the Earth’s surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a...
Micro-plankton are a crucial component of pelagic food webs, responding rapidly to environmental changes, and providing a first step in the acquisition and transfer of nutrients to life in the ocean. In addition to the uptake of carbon, phytoplankton provide essential fatty acids (FAs) that can limit the growth of...
: ______________________________________________________
Maria Teresa Kavanaugh
Micro-plankton are a crucial component of pelagic food webs, responding
Evaporation synergy is the phenomenon in which two porous medium textures that share a common vertical boundary experience a higher cumulative evaporation than either homogeneous texture can produce. Studies that have been conducted to date address this phenomenon in relatively fine and coarse sands but not in finer textured soils...
Irrigated agricultural production in sandy soils presents several unique challenges to growers, including naturally high permeability, low native water retention, as well as high rates of water drainage losses and leaching of chemicals to the shallow aquifers. This study is an initial investigation into water motion in the sandy agricultural...
Neurofibromatosis type 2 (NF2) is a genetic disorder caused by the inactivation of the
merlin tumor suppressor gene. NF2 patients develop bilateral vestibular schwannomas
(VS) and other nervous system tumors with no effective drug treatment option. In
pathological conditions, including NF2, production of the oxidant peroxynitrite leads to
protein tyrosine...
This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
Independent fission product yields are primary input nuclear
data in the evaluation of nuclear reactor after-heat when using a
nuclide-decay summation method. The error in yield values is one
of the major causes of uncertainty of this calculation. Since only
a small fraction of the fission product yields has been...
Grain yield and grain protein are often negatively associated in
wheat. When yield increases and grain protein decreases, there can be
an adverse effect on the milling and baking quality if the desired end
product is bread flour. It has been suggested that this inverse
association is the result of...
Oceanic fronts mark the boundary between two water masses and are often sites of complex bio-physical processes and multi-trophic level interactions, making them particularly important features in marine ecosystems. As global climate change induces multi-scale shifts in the driving physical mechanisms of fronts, spatiotemporal tracking of frontal variability can aid...
The veteran population, about 18.5 million Americans in 2016 (US Census Bureau, 2018), is particularly at risk for mental health problems. As an example, the suicide rate of veterans is about one and a half times higher than the general population (US Department of Veteran Affairs [DVA], 2018b). Another group...
The genus Phytophthora comprises numerous plant pathogens in both natural and managed ecosystems. For Phytophthora spp. that infect roots, dispersal occurs in soil water through a combination of advection and swimming of specialized motile propagules (zoospores). Specific biological and physico-chemical processes, however, remain poorly understood, due to difficulties in studying...
Wheat (Triticum aestivum L.) is one of the major crops produced in the U.S. Pacific Northwest, a region known for its wheat production for international export. Wheat production in the region is threatened by diseases such as Cephalosporium stripe and stripe rust. Cephalosporium stripe is a vascular wilt disease of...
This essay provides an assessment of the human, social and financial resources that Oregon Latino immigrant-serving nonprofits have available to achieve their mission of promoting Latino immigrant integration and civic engagement practices. Under the framework of immigrant integration, this study examines the strategies Latino nonprofits rely upon to achieve their...
Red radish (Raphanus sativus L.) anthocyanins were extracted from liquid
nitrogen powdered epidermal tissue using acetone and chloroform and isolated using
C-18 resin. Chemical structure and conformation of major pigments were elucidated
by 1-D and 2-D NMR, Mass Spectroscopy, HPLC, and spectral analyses. Two novel
di-acylated anthocyanins, pelargonidin 3-0-[2-0-(β-D-glucopyranosyl)-(6-0- trans-p-coumaroyl-...
Infiltration of highly concentrated solutions into unsaturated sand is suspected to be affected by the liquid-gas interfacial tension between the resident water and that of the infiltrating solution. The wetting of non-porous solid surfaces by liquids is commonly quantified by contact angle measurements. However, it is well known that wettability...
Understanding the mechanisms controlling colloid transport and deposition in the vadose zone is an important step in protecting our water resources. Colloid transport in unsaturated porous media was studied using X-Ray Microtomography (XMT), which is a non-destructive imaging technique that provides three-dimensional images at a resolution on the order of...
This study explores the use of predictive mapping techniques in developing Landtype Association (LTA) maps for use in natural resource management. These maps are produced for the USDA Forest Service on a regional basis at a 1:100,000 scale. The goal of this study is to develop and test a method...
Microseris laciniata is a perennial, self-incompatible
species classified in subgenus Scorzonella. It is
morphologically the least specialized species in the genus,
in contrast to the members of subgenus Microseris, which
are morphologically advanced, self-compatible annuals.
First-generation hybrids were available from crosses
involving eight populations of two subspecies of Microseris
laciniata...
Fluctuations in one system affect adjacent systems; mechanistic understanding of linkages helps conservation efforts be more effective by focusing on influential species and areas that facilitate connections between ecosystems. This study explored marine-derived nutrient inputs to adjacent terrestrial communities. We quantified wrack (seaweed and other organic matter) deposition at sites...
Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping...
A fruit color descriptive study was conducted on 'Max' and 'Sensation' Red Bartlett, 'Columbia' and 'Gebhard' Red Anjou, 'Rogue Red', 'Rosired', 'Red Clapp' and 'Cascade' red pear varieties. A parallel comparative study was done to test differences between related red strains. 'Max' was compared with 'Sensation' in three different growing...
Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually lead to tree death. To investigate the long-term impacts of dwarf mistletoe on gas exchange of host western hemlock trees, I compared growth, gas...