Internal dosimetry models show a representation of how radionuclides move through the body. This study takes a look at radiation wounds by modelling a puncture wound to the hand using Microshield software. An analysis of these models provides a triangulation method that could be used to investigate wound characteristics, as...
Some studies using regional climate models (RCMs) suggest a weakening of the climatological rain-shadow along the Cascade and Sierra Nevada mountains during the western US cool-season. To identify the possible mechanisms of rain-shadow weakening under warming, a new set of 30-year, high-resolution (6 km) pseudo-global warming (PGW) simulations were analyzed...
The hydrologic cycle on Earth comprises the transitions among the solid, liquid, and gaseous phases of water. Understanding the hydrologic cycle is of course important for climate science, but also for agricultural, drinking water, and disaster preparedness purposes. Improvements in satellite observations and general circulation models (GCMs) have led to...
Changes in glacier length reflect the integrated response to local fluctuations in temperature and precipitation, but when do such changes indicate forced climate change, and when do they indicate natural variability? In this study, we simulate the past ~1000 years of glacier length variability across the globe using the 3-stage...
As engineered nanomaterials (ENM) become more common in consumer products, it is crucial to rapidly assess toxicity of unique ENM. Previous studies rarely focused on standardizing nanotoxicity testing, leading to inconsistent and irreproducible results. This study characterized a variety of ENM of different size, shape, core type, and surface charge...
Concentrated solar power (CSP) along with thermal energy storage (TES) has the potential to provide reliable energy from an intermittent source. TES is used to store energy while the sun is shining, allowing for the stored energy to be used when the sun is no longer shining. There are many...
Given its abundance and accessibility, exploiting solar energy is a powerful approach to reduce dependency on fossil fuels for energy generation. Thermochemical reactions using concentrated solar power at high temperature are an attractive method of energy storage in support of concentrated solar power (CSP). Thermochemical energy storage of on-sun thermal...
Natural freshwater availability is decreasing as the global population increases. Advances in desalination technologies aim to produce fresh water in an economical way. More sustainable energy sources are desired for these desalination plants to limit the carbon footprint of water production since global carbon dioxide production is exacerbating freshwater scarcity....
Effective storage and release of low-to-moderate temperature thermal energy (e.g. solar thermal or geothermal) could be transformational for applications such as space heating/cooling, domestic hot water, or off-grid cooking. Good candidates for thermal energy storage in this temperature range include latent heat storage (LHS) systems and thermochemical energy storage (TCES)...
Global energy needs are continuously increasing while fossil fuels remain an uncertain resource. With a growing population and demand for energy, alternative energy sources are being pursued to power the future. Fossil fuels are an unsustainable resource that brings along problems of climate change and atmospheric pollution. Concentrated solar power...
The goal of this project is to better characterize particle movement in a multi-channel fluidized bed. Fluidized beds are commonly used for heat transfer with the rapid fluidization and homogeneous heat distribution. By characterizing this particle flow, it would allow for an improved understanding of the heat transfer mechanisms within...
Nonthermal electrical plasmas can allow energy intensive reactions to occur without the use of high operating temperatures or pressures. This is because the collisions of electrons accelerated through an electric field with molecules is the cause of reactions as opposed to thermal collisions between molecules. In this study, the production...
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Figure 2.3: Circuit diagram of the DC plasma system. R1 and R2 are resistors of 200 kΩ and 1
k
Finding renewable sources of agricultural fertilizer will be necessary to ensure a stable food supply for future generations. Phosphorus is of particular concern, since mining phosphate rock is the main source and reserves are forecasted to deplete in the next 50 – 200 years. Human urine contains substantial amounts of...
In this work, a hybrid thermochemistry compressed air energy storage (CAES) system is investigated. Following a review on chemical reactions investigated for use in thermochemical energy storage (TCES) systems, from these chemistries, the conversion of magnesium carbonate, MgCO3, to magnesium oxide, MgO, and carbon dioxide, CO2, was further analyzed for...
Utilization of solar energy or wind energy for electricity production is inherently challenging due to the diurnal and seasonal variations and normal intermittency. Effective, high efficiency storage methods need to be developed for further advancing renewable energy utilization. Endothermic chemical processing and thermochemical energy storage can be both employed as...
Stranded natural gas and biogas comprise a vast energy resource that is mostly wasted via flaring. This represents an opportunity to investigate novel ways to harness this resource. Nonthermal plasmas consist of excited electrons, ions and neutral atoms/molecules that have the ability to disrupt chemical bonds at ambient temperatures and...
Solar thermal energy can be stored and later converted to electrical energy using a combination of thermochemical energy storage (TCES) and a thermoelectric generator (TEG). This TEG and TCES combination illustrates a potential route for clean electricity storage from renewable energy. TCES allows for thermal energy from the sun to...
The construction industry employs about 7% of the total US workforce, and yet it accounts for 15.7% of all occupational fatalities. Specifically in 2011, there were 721 deaths in construction, second only to transportation with 733. The cause of a large number of these construction deaths can be attributed to...
The purpose of this investigation was to determine the validity and
reliability of the Nicholas Manual Muscle Tester (NMMT), a portable
dynamometer, as a measure of the isometric strength in women with arthritis.
Female subjects (N=13; 66 ± 13.89 yrs.) with arthritis were tested for
isometric muscle strength on the...
This thesis experimentally determines the feasibility to creating C4 to C10 hydrocarbons from CO2, CO, H2, H2O and CH4. This is done in two steps, the initial step is the formation of ethylene through DC electrical glow discharge at ambient pressure while the second step is through temperature pulse controlled...
Thermochemical water splitting cycles have been conceptualized and researched for over half a century, yet to this day none are commercially viable. The heavily studied Sulfur-Iodine cycle has been stalled in the early development stage due to a difficult HI-H₂O separation step and material compatibility issues. In an effort to...
Over the past century, life expectancy in the United States has dramatically increased leading to an increasingly aging population with people reaching, and spending more years in ‘old age’. While this unprecedented shift in population demographics represents great strides for humanity, it is not without cost. One consequence of longer...
MOTIVATION: Estimation of bacterial community composition from
a high-throughput sequenced sample is an important task in
metagenomics applications. Since the sample sequence data
typically harbors reads of variable lengths and different levels of
biological and technical noise, accurate statistical analysis of such
data is challenging. Currently popular estimation methods are...
A present abundance of biomass and a decreasing supply of petroleum signal the need for efficient pathways from renewable feedstocks to high value chemicals. One such class of chemicals is oleofurans, molecules comprised of a furan ring and carbon chain which can be used to make powerful hard water surfactants....
The enclosed thesis presents an algorithm, programmed
in FORTRAN IV, which generates the radii for
the objective of an astronomical refracting telescope.
The results are analyzed by the Trigonometric Ray
Trace, and found to have tolerable amounts of spherical
aberration, chromatic aberration and coma.
The objective of this thesis was to investigate the use of the Jacobian Free Newton Krylov Method (JFNK) with physics based preconditioning for solving coupled radiative transport and material energy balance. Modeling of these physics is important in inertial confinement fusion and other high energy density systems. In this thesis,...
Riparian zone conservation is vital as species’ ability to adapt to a changing climate and pressure from land use is constantly tested. The unique microclimates of riparian zones offer cooler temperatures and resourceful habitats for aquatic and terrestrial organisms. This is essential during seasonal ceased flow regimes when water availability...
The optical response of metallic structures is dominated by the dynamics of their free electron plasma. Plasmonics, the area of optics specializing in the electromagnetic behavior of heterogeneous structures with metallic inclusions, is undergoing rapid development, fueled in part by recent progress in experimental fabrication techniques and novel
theoretical approaches....
Living in the Pacific Northwest, we are acutely aware of the dangers posed by wildfires. Largely due to the worsening effects of climate change, this danger is only increasing. Along with causing property and economic damage to those communities affected by wildfires, exposure to the smoke generated by wildfires can...
Climate change is a global phenomenon, but natural selection occurs within landscapes. A central tenet of landscape ecology is that mobile species depend on complementary habitats, which are insufficient in isolation, but combine to support animals through the full annual cycle. For coldwater fishes, it is widely assumed that maximum...
Long-run food price changes respond to long-run changes in food demand, quasi-fixed and variable production factors, and agricultural productivity. Recent global food-price volatility puts a renewed spotlight on the trends and sources of any agricultural productivity growth. Because food prices’ most critical effects are on human hunger, it is especially...
We examined the spatial and temporal variability of stream carbon dioxide (CO₂) and the drivers of these variations in a headwater catchment. To examine temporal variation and drivers, we measured stream and hyporheic pCO₂ at high temporal resolution over 11 months in a 95.9-ha forested headwater catchment in the Western...
One post-transcriptional mechanism that regulates the progression of cancer and other diseases involves small 22-23 nucleotide sequences called microRNA (miR). Early detection of small changes in concentration of these biomarkers holds potential to diagnose diseases at their earliest stages. Use of current nucleic-acid based biosensors, like molecular beacons, for in...
Douglas-fir (Pseudotsuga menziesii) is a commercially and ecologically important tree species native to western North America. The foliar pathogens Phaeocryptopus gaeumannii, the causal agent of Swiss Needle Cast, and Rhabdocline species, the causal agents of Rhabdocline needle cast, are two important pathogens specific to Douglas-fir. These pathogens are highly influenced...
Ascorbic acid, or vitamin C, is well known as a co-factor for proline-hydroxylase and as an anti-oxidant. However, it is also capable of forming covalent bonds, particularly in the role of a nucleophile, henceforth termed 'ascorbylation'.
The ascorbylation of electrophiles can occur under physiological conditions. Furthermore, there are a number...
Reintroduction programs are used to re-establish species back into their historical habitat. Most reintroduction programs have failed and few papers have evaluated factors that may be important to Pacific salmon. The 158 meter tall Cougar Dam has blocked Chinook salmon (Oncorhynchus tshawytscha) from accessing 40 kilometers of historical spawning and...
Oomycete and fungal pathogens threaten food, fiber, and forests around the world. With climate change, these pathogens are expected to emerge more frequently. Evolution can facilitate their emergence through mechanisms such as mutations that change or expand host range. Characterizing evolutionary mechanisms in plant pathogens will contribute to our ability...
The research presented herein represents an effort to combine the ultra-smooth surface of an amorphous metal thin film (AMTF) with a solution-processed dielectric synthesized via prompt inorganic condensation (PIC). Analysis of dielectric film quality is carried out via electrical measurements of metal-insulator-metal (MIM) diodes. Anneals at 500 and 700 °C...
Dinosaurs represent one of the most successful evolutionary radiations of terrestrial vertebrates, with a myriad of forms that dominated the terrestrial environment for over 180 million years. Despite the fact that dinosaurs are the focus of extensive popular and scholarly investigation, relatively little is actually known of their biology. The...
This thesis focuses on the investigation of extraterrestrial tracers Ir, Pt and 3He in polar ice cores. These tracers may be used to identify characteristics of interplanetary dust particles, and to quantify the flux of extraterrestrial material during impact events, certain volcanic eruptions, and stable background periods. In the first...
An asymmetric approach to the synthesis of byssochlamic acid (1) is
described. Regioisomeric enzymatic differentiation is described in the selective
hydrolysis of dimethyl ester 30 by porcine liver esterase. Chiral dimethyl ester 42
was prepared by desymmetrization of cyclopentene 34 using porcine liver
esterase. A key intramolecular [2+2]cycloaddition-cycloreversion
photometathesis of...
RNA silencing plays a critical role in plant defense against viral infection. Plants use virusderived
small interfering RNA to target and silence invading viruses. The antiviral silencing
pathway can be broken down into three conceptual stages: initiation, amplification, and systemic
movement. The molecular mechanisms of silencing initiation are not well...
This paper presents an exposition of the stochastic models
for the Brownian motion. The results of Einstein and Wiener are
presented, together with the Uhlenbeck-Ornstein process which
gives a more realistic model of the Brownian motion of a particle.
Finally, applying a one-one transformation on the forward
Kolmogorov equation we...
We present a method for deterministically solving the consistent temperature and frequency dependent phonon radiative transport problem. We use the single relaxation time (SRT) approximation in the Self-Adjoint Angular Flux (SAAF) form with discrete ordinates (S_N) angular discretization method and continuous finite element method (CFEM) for spatial discretization. Included are...
Dwelling on the bottom of large rivers to high alpine streams, freshwater sculpins (genus Cottus) occur in high densities across the Pacific Northwest, with 21 currently recognized species found in the Pacific Northwest. Sculpin fill many ecological roles, with some species serving as important prey sources, and others competing with...
The factors that cause abdominal aortic aneurysm rupture were investigated. Included
in this study were aneurysm volume, thrombus thickness, lumen area, thrombus area,
the average stress acting on the aorta, and the maximum stress on the aorta. The
geometric values were obtained by tracing a series of computerized axial tomography...
The weather pattern and trends associated with heat flux events (HFEs) over the Gulf Stream (GS) are examined as part of the CLIMODE project. A large portion of GS turbulent heat loss occurs during distinct synoptic scale events with a duration of one to two days. Forty percent (40%) of...
Current methods in traction force analysis rely on a homogeneous extra-cellular matrix and
embedded microbeads to track deformations. The efficacy of these methods decreases when the matrix is not homogeneous. In heterogeneous matrices, beads often aggregate in regions of higher matrix density and float in regions where matrix substrate is...
Headwater streams represent the majority of the drainage area of a river network and provide many critical functions supporting aquatic and terrestrial ecosystem health. The riparian zones that surround these streams are transitional areas between terrestrial and stream ecosystems, which provide key habitat for aquatic and terrestrial organisms, especially during...
The Experimental Advanced Airborne Research Lidar ‐ B (EAARL‐B), which was built and deployed by the U.S. Geological Survey (USGS) in 2014, is a novel topographic‐bathymetric lidar system. While retaining a number of features that were pioneered in the original National Aeronautics and Space Administration (NASA) EAARL system (e.g., low...
Understanding the behavior of hydrophobic membranes is important for applications where separating a gas from a liquid-gas mixture is beneficial. For example, in-situ vapor extraction can be used in microscale heat sinks to improve heat transfer and flow stability. In this study, gas is experimentally evaluated flowing through flexible polytetrafluoroethylene...
Efficient usage of resin is of critical importance to industry in the manufacture of wood composite panels, because resin represents a significant proportion of product costs. However, resin efficiency is poorly defined in literature, making it difficult to compare manufacturing processes in quantifiable terms. Additionally, resin content in the product...
Coastal flooding and erosion are major concerns for low lying coastal communities -- particularly in light of accelerated sea level rise and climate change. To improve quantitative understanding of the physical drivers of both flooding and coastal landscape change, this dissertation explores coastal morphodynamics bridging the land-sea interface on modally...
The goals of this dissertation are centered on understanding changes in Earth surface and climate systems through the use of geologic proxies as records of past changes in these systems. Specifically, this dissertation (1) establishes a new chronology for retreat of the Ross Sea sector of the West Antarctic Ice...
This collection of three manuscripts serves to improve methods for collecting, interpreting, and utilizing autocorrelated data from headwater stream networks. Each stream network is comprised of linear segments. These segments lie within a unique branching structure that connects the segments via flowing water, and the connectivity provided by water varies...
The Neutron radiography facility (NRF) at Oregon State University (OSU) has been modified to begin working on the non-destructive evaluation of concrete materials to study the early stages of shrinkage, cracking, and water transport of concrete during the curing process.
The objective of this work is to investigate the efficiency...
The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) purports to assess emotional intelligence, which includes the ability to successfully identify and manage emotions. To test the validity of this claim, 21 students took the MSCIET along with a several other performance measures and personality scales, and their scores were correlated. The MSCEIT...
Knowledge compilation improves search-intensive problem-solvers that are easily specified but inefficient. One promising approach improves efficiency by constructing a database of problem-instance/best-action pairs that replace problem-solving search with efficient lookup. The database is constructed by reverse enumeration- expanding the complete search space backwards, from the terminal problem instances. This approach...
Multiagent approaches are well suited to designing autonomous solutions for systems that feature complex interactions between many individuals such as in autonomous traffic systems and multi-robot exploration systems. However, creating autonomous agents that function effectively in these systems is a challenging task. In these complex environments, agents need informative reward...
The advancement of the US energy grid is a necessary task to undertake as renewable energies like wind and solar power become more and more prevalent in our energy sector. However, due to uncontrollable factors such as wind speed and cloud cover, the intermittence of these energy sources continues to...
Dot mapping is a traditional method for visualizing quantitative data, but current automateddot mapping techniques are limited. The most common automated method places dotspseudo-randomly within enumeration areas, which can result in overlapping dots and verydense dot clusters for areas with large values. These issues affect users’ ability to estimatevalues. Graduated...
Outdoor adventure education (OAE) has long held on to the assumption that learning is transferred to participants’ lives (e.g., Gass, 1985). Recent scholars have contested this assumption, noting that learning transfer may not be a complete lens through which learning is viewed. Transformative learning theory (e.g., Mezirow, 1991) has been...
Research was initiated to find a secondary bleach to remove brown discoloration on sulfur dioxide brined sweet cherries. In addition, studies were carried out to determine the effects on texture of not only the secondary bleaches, but also the primary bleach (sulfur dioxide). Three bleaches were found to remove the...
One of the major disadvantages of wood is that it swells and shrinks when water is adsorbed or desorbed below the fiber saturation point. This property causes numerous problems when wood is used as a structural material. Consequently, a considerable amount of research has been conducted on this problem, but...
Polystyrene thin film surfaces are commonly used to study the interactions of macromolecules, such as proteins, with surfaces. Polystyrene films oxidized in UV light become more hydrophilic, however these surfaces have a limited shelf life because they are reduced over time. Experiments were performed to determine the effect of radiation...
This dissertation presents novel, field-activated smart material systems for the actuation and control of autonomous robots. Smart materials, a type of material whose properties can be changed with an external stimuli, represent a promising direction to expand upon existing robotic control and actuation methods, particularly in the sub-fields of soft...
Improved cookstoves have been designed and disseminated for several decades in an effort to address the human health and environmental issues caused by the inefficient, traditional biomass cooking and heating methods used by 40% of the world’s people. Engineers and designers working on these improved stoves have tended to focus...
The task of inductive learning from examples places constraints on the representation of training instances and concepts. These constraints are different from, and often incompatible with, the constraints placed on the representation by the performance task. This incompatibility is severe when learning functional concepts and explains why previous researchers have...
Distributed version control allows developers to manage software evolution among distributed development teams. But it does not eliminate all consistency and concurrency issues, and instead introduces additional complexity when merging code. And resolving merge conflicts is nontrivial when automated merging fails. In such cases, developers are forced to inspect the...
Although plant remains, such as opal phytolith and charcoal analyses, have been used since the beginning of the 20th century to reconstruct past environments by ecologists and botanists, only recently have these techniques been considered by archaeologists in understanding the past at the site level. This study employs opal phytolith...
This paper introduces a method that improves the performance of a problem solver by reformulating its domain theory into one in which functionally relevant features are explicit in the syntax. This method, in contrast to previous reformulation methods, employs sets of training examples to constrain and direct the reformulation process....
Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris...
The objective of this paper is to conduct a geographical inventory
of a sand and gravel site, Lower Kiger Island, so as to identify and
evaluate other potential land uses subsequent to the extraction of its aggregate
resources. This information is intended to aid citizens, land use
planners, and sand...
By 1900 domestication was a promising, if somewhat vexed, subject in biology. Volumes had been written about domestication, but little serious scientific inquiry was directed toward the phenomenon. Expertise lay with practical men, primarily breeders and fanciers. The bulk of scientific commentary on domestication came from anthropologists who derived theories...
Since 1983, the Oregon legislature and the Land Conservation
and Development Commission have been attempting to develop a
process whereby secondary resource lands can be identified and
designated. The most recent attempt at developing a secondary
lands model was completed in 1990 and was tested in six Oregon
Counties. Planners...
What does comida rica mean? In this thesis, I explore the meanings of comida rica, sana, and de nuestra tierra through the discourses, practices, and kitchen geographies in six urban, highland households in the Ecuadorean Andes. This research, as part of a larger investigation carried out by a team of...
The purpose of this study is to illuminate the presence
and rhetorical effect of anecdotes in President Clinton's
major health care address. It is the health care debate that
shows most clearly how Clinton tries to direct a multi-level
campaign that attempts to identify his interests (passage of
the Health...
Facial recognition has become increasingly important in recent years, due to the wide range of applications it has in fields such as security, surveillance, and human-computer interaction. Three popular methods for facial recognition are the Principal Component Analysis (PCA), Karhunen-Loeve Expansions, which is fundamentally a continuous form of PCA but...
Dry reforming of methane to syngas using CO2 was performed in a solar-driven milli-scale reactor, which converts solar energy to chemical energy. The process aims to upgrade the energy content of the feed stream using sustainable energy. The effect of mean residence time, temperature and CO2:CH4 ratio on conversion and...
Metallic glasses (also referred to as amorphous metals) have been gaining interest in the materials science community in recent years. These amorphous materials demonstrate promising properties compared to their crystalline counterparts that include much higher strength and elastic strain limit, better corrosion and wear resistance, superior soft magnetism, and an...
Historical forest harvesting practices were reviewed in the original Alsea Watershed Study where they found increased energy
loading to the stream and produced higher stream temperatures. This was an important early research site that led to the
development of contemporary forest management practices to protect water quality and fish habitat...
In the contemporary U.S., the state, through the Legislative Assembly, the State Board of
Education, and the Department of Education, sets policies for K-12 education. These include goals
and standards that affect the kinds of influences local officials, parents, and students can have
on various education programs, required and elective...
The study related the density of herbivores to the length and density of Prionitis spp. in Oregon’s coastal tidepools. Oregon’s coastal rocky intertidal tidepools contain a variety of species interactions, including algal grazing by herbivores. The red branched algae Prionitis spp. is found throughout the rocky intertidal in the low...
Despite numerous techniques for measuring and estimating water depth, bathymetry in the nearshore zone is notoriously difficult to map. Dangerous sea states, noisy environmental conditions, and expensive survey operations, particularly in remote areas, contribute to the difficulties of obtaining data along the coast. Global datasets, derived mainly from satellite altimetry...
Nickel (Ni)-based alloys with a high chromium (Cr) content are frequently employed in applications where elevated temperatures and/or corrosive environments are present due to their excellent corrosion resistance and mechanical properties. However, a gap exists around the formation, and kinetics of long-range order (LRO) Ni2Cr phase in both model binary...
The cleanliness of water is a major issue with regards to humanity's continued survival. The chlorination and chloro-amination of water is essential to the creation of microbiologically clean water. However these processes also give rise to oxidative byproducts such as nitrosamines. In particular, due to its high toxicity, N-Nitrosodimethylamine (NDMA)...
A six degree of freedom (6DOF) point-absorber wave energy converter (WEC) called LUPA is being developed at Oregon State University. This research focused on analyzing a full- scale LUPA, called LUPA20, to answer the following questions: 1) How does a full-scale WEC perform due to various factors; 2) What are...
Adhesive use is becoming increasingly common in manufacturing processes. The advantage of adhesives are light weight components, non-destructive fastening techniques and distribution of loads over the applied bond region. Modeling the behavior of adhesive bond lines in fastening joints can help in the design process to make an optimized joint,...
The purpose of this research is to provide a simple fabrication method for zinc oxide and antimony sulfide based thin film solar cells. Both a ZnO nanorod electron conducting structure and a stibnite absorber show promise in a solar cell. Initial attempts at using only ZnO and Sb2S3, however, resulted...