A wide variety of hydrodynamic theories are utilized to approximate a Wave Energy Converter’s (WEC) equation of motion. Numerous theories have been refined in order to improve numerical approximations of WEC dynamics. When incorporating refined hydrodynamic theories into numerical models, there are distinct impacts on WEC rigid body motions, cable...
Wind energy has become a crucial resource in sustainably meeting increasing global energy demands. Recently, offshore wind energy has been gaining traction due to its higher gross resource and larger unclaimed real-estate relative to its onshore counterpart. Floating offshore wind turbines (FOWTs) are increasingly popular, particularly designs with semisubmersible platforms....
Society derives many critical and irreplaceable values from forests. With a growing global human population and rates of consumption, forests are under increasing pressure to provide all these values simultaneously. To meet societal demands for wood products, tree plantations are becoming increasingly common and are replacing native forests. Yet, forests...
The optical and electronic properties of amorphous oxide thin films depend crucially on chemical composition, and deposition process variations which give rise to sub-gap defect states. Consequently, there is a need for a reliable, high-throughput method to extract sub-gap defect densities of states in amorphous oxide thin films. We present...
As the global demand for natural resources increases, more land will be intensively managed for the production of commodities such as timber, with potential consequences to biodiversity, ecological functioning and ecosystem services provided to society. Although there is strong consensus that intensive land management practices can negatively affect biodiversity, less...
The Klamath-Siskiyou Ecoregion of southwest Oregon and northern California is greatly departed from its historic, mixed-severity fire regime. This departure manifests in larger wildfires, greater proportions of high burn severity within wildfire perimeters, and decreased diversity of post-fire vegetation successional stages and trajectories across the landscape compared to historical norms....
Global biodiversity decline is primarily driven by habitat loss. Deforestation, the primary driver of terrestrial habitat loss, is increasing worldwide, with the most significant impact in the world biodiversity hotspots. Sadly, specific knowledge of such impacts in biodiversity-rich but data-poor countries are still unknown, and many national and regional narratives...
The concept of the fundamental niche is frequently used in ecology to define the set of environmental conditions needed by a species to survive and reproduce (Hutchinson 1957). In contrast, the realized niche constitutes the locations where a species actually occurred, which is a function of both the environmental (abiotic)...
Two experiments were conducted to evaluate the use of wet brewers' grain (WBG) alone and with straw so it can be used as part of the sole ration for ruminants. In Exp. 1, WBG was ensued alone and was mixed with one of two straws, wheat or tall fescue grass...
Recent climatic warming trends and increases in the frequency and extent of wildfires have prompted much concern regarding the potential for rapid change in the structure and function of forested ecosystems around the world. Episodes of mortality in wildfires and insect outbreaks associated with drought have affected large areas and...
Little is known on the importance of riparian areas to birds near small headwater streams in mesic forests. Progress towards understanding limiting factors that affect bird populations has been difficult because of lack of information beyond the breeding period. I compared bird assemblages between headwater riparian and upland areas throughout...
Strong ground motions from earthquakes can result in the reduction of the shear modulus and wave propagation characteristics of soils, and can produce liquefaction and cyclic softening during shaking and for some time following the seismic event. While the ground motions produced from controlled blasting are different than those in...
A growing body of work reveals that animal-mediated pollination is negatively affected by anthropogenic disturbance. Landscape-scale disturbance results in two often inter-related processes: (1) habitat loss, and (2) disruptions of habitat configuration (i.e. fragmentation). Understanding the relative effects of such processes is critical in designing effective management strategies to limit...
Lone Lake is an approximately ninety acre lake in Langley, WA on Whidbey Island. Since 2008, Lone Lake has experienced a number of harmful cyanobacterial blooms (cyanoHABs). Since 2016, however, the intensity of these cyanoHABs have impacted both ecosystem functions and human activities in the watershed. In June of 2020,...
Juvenile chinook salmon (Oncorhynchus tshawytscha) were experimentally infected with Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease (BKD), to investigate the effects of BKD on three aspects of juvenile salmonid performance: (1) predator avoidance ability; (2) smoltification; and (3) physiological responses to stress. For these experiments, fish with...
Chlorinated and non-chlorinated solvents are used in a variety of industrial processes and as a consequence, they have become environmental contaminants as well. Because of this, they lead to both occupational and environmental exposures. Exposure to these compounds can potentially result in various forms of neurological damage with a wide...
This thesis consists of two papers in manuscript format. The first paper presents optical measurements of tsunami inundation through an urban waterfront in a laboratory wave basin. The physical model was constructed at 1:50 scale and was an idealization of the town of Seaside, Oregon. The paper presents an analysis...
Biochar has shown promise as a soil amendment for improvement of agricultural and forest productivity, remediation of heavy metals, and sequestration of carbon, but has not yet been adopted for widespread use in any of these applications. By assessing the production potential as a carbon sequestration tool, and the stability...
Informed conservation of small mammals, ecosystems, and predators requires a detailed understanding of how small mammals species and communities vary in both space and time, as well as the relative cyclicity and synchrony of this variation. This variation can be especially informative to land managers interested in manipulating the abundance...
The effect of clipping and supplemental nitrogen application on
seed production of Linn perennial ryegrass and Merion Kentucky bluegrass
was studied. Clipping and nitrogen treatments did not significantly
affect the seed yield of Linn perennial ryegrass during the 1967
growing season. The seed yield of Merion Kentucky bluegrass was
significantly...
Situated cognition theory emphasizes the role that social and material contexts have on learning and knowledge application. Several studies of engineering workplace environments have noted differences between the social and material contexts of the workplace and those of undergraduate engineering education. No existing research has studied the social and material...
Understanding the past, present, and future behavior of our nation's shorelines is vital for sensible coastal management. Localized areas of erosion, termed "erosional hot spots", can shift the shoreline landward threatening coastal infrastructure (Kraus and Galgano, 2001; Stauble and Gravens, 2004; McNinch, 2004). One specific type of erosional hot spot...
Gray wolves (Canis lupus) are the most socially polarizing species listed under the Endangered Species Act. Wildlife management practices at local, state, and federal levels include lethal control to resolve stakeholder and wolf conflicts as a last resort. There is little experimental evidence that lethal control is effective in this...
A three-part study was conducted into the impact of physiological and ecological variables on the net isotopic fractionation of hydrogen, α[subscript K₃₇], expressed in C₃₇ alkenones. First, alkenone-producer production, abundance, and export were characterized in the summertime Gulf of California and Eastern Tropical North Pacific using compound-specific, labeled in situ...
While community ecologists have traditionally focused on local-scale processes, it has become apparent that a broader perspective, which explores the community-level ramifications of material fluxes within and between ecosystems, is necessary to effectively evaluate bottom-up influences on community structure and dynamics. In this dissertation, I employed ecosystem principles to understand...
As electronics reach nanometer size scales, new avenues of integrating biology and electronics become available. For example, nanoscale field-effect transistors have been integrated with single neurons to detect neural activity. Researchers have also used nanoscale materials to build electronic ears and noses. Another exciting development is the use of nanoscale...
This research design was based upon the mutual relevance
between the fields of education and anthropology to cause cognitive
cultural awareness by the teachers of adults as well as visibility
within the Mexican American ethnic group.
Specifically the purpose of this study was twofold:. (1) to
determine whether the adult...
Laboratory scale microcosm studies were conducted using site specific groundwater and aquifer solids to assess the feasibility of stimulating indigenous microorganisms in-situ to biologically transform Trichloroethylene (TCE) and its lesser chlorinated daughter products dichloroethylene (DCE) and vinyl chloride (VC). Three different treatments were conducted to determine the best approach for...
Flexible electronics processing techniques were applied to integrate a glucose sensor with a hormone-delivery catheter in order to create a cheap and minimally invasive method for patients with type 1 diabetes to continually monitor and control their blood sugar levels. Ultimately, this work intends to move toward the development of...
Electrostatic gating of nanomaterials allows researchers to control carrier density and shape potential barriers that confine carriers. Lithographic patterning followed by metal deposition is the standard technique to define electrostatic gates; however, the methods of fabricating these devices often involve harsh processing. For example, taking a material to high temperatures...
In this study, I examine the influence of habitat gradients created by the 1980 eruption of Mount St. Helens, Washington USA on a recently established Rainbow Trout (Oncorhynchus mykiss) population in the Spirit Lake basin. My goal was to evaluate the responses of fish in seven streams across a volcanic...
Sustainable elk (Cervus canadensis) habitat management on U.S. Forest Service (USFS) lands involves a complex relationship between management practices and ecological processes. A relatively novel Rocky Mountain elk population (Cervus canadensis nelsoni) on the Plumas National Forest (PNF) in northeastern California became established in the early 2000s, but there is...
Embryonic diapause is a reproductive strategy widespread in the animal kingdom. This phenomenon is defined by a temporary arrest in blastocyst growth and metabolic activity within a quiescent uterus without implantation until the environmental and maternal milieu become favorable for pregnancy to progress. We found that uterine Msx expression persists...
Early seral forests regenerating from stand-replacing disturbances provide unique habitat for many species in productive, temperate forest landscapes and contribute to supporting biodiversity. Population declines in some species associated with early seral forests have prompted concerns about the conservation of these habitats, particularly the characteristic structural and compositional complexity associated...
Aggregate piers have been used for centuries, with increasing occurrence in the last few decades. Their usage has been driven by land development demand and enabled through equipment and engineering improvements. Understanding the principles controlling bearing capacities and serviceability performance has been an ongoing area of interest for structures supported...
Columbian black-tailed deer (Odocoileus hemionus columbianus) are important economically, ecologically, and culturally as an indigenous species in western Oregon. Oregon Department of Fish and Wildlife (ODFW) observed declines in black-tailed deer populations since the late 1980’s and attributes these declines to reduction in quality and availability of habitat, following the...
The seismic response of deep deposits of liquefiable and cyclic-softening susceptible soils has presented the geotechnical profession with significant engineering challenges. Strong ground motions may serve to soften soils under cyclic shear, trigger liquefaction, and produce damaging displacements as a consequence. This study improves the understanding of the in-situ, nonlinear,...
Some of the most pressing conservation concerns involve declining populations of species with low fecundity and highly specialized foraging and reproductive requirements. Yet, we often lack a functional understanding of how individuals of those species interact with their environment, specifically how their movement is affected by human-induced changes. In order...
Algae can be used in a variety of wastewater systems to capture nutrients while fixing carbon dioxide from the atmosphere. I conducted field trials at three locations in Oregon with both corn and potato crops to assess the agronomic value and environmental impact of using the resulting algal biomass as...
This study uses an existing database of dynamic loading tests of driven piles installed in the Puget Sound Lowlands to improve the reliability of axial performance. First, the unit shaft resistances developed from stress wave signal matching to dynamic records of pile installation are used to develop an effective stress-based...
Personal health monitoring tools, a subset of point-of care-diagnostics, enable more frequent testing of chronic health conditions outside of a clinic setting and can inform personalized therapy or support telehealth diagnostic capabilities. While there is evidence that regular monitoring of chronic conditions can lead to better health outcomes and lower...
This dissertation focuses on extending the application scope of surface enhanced infrared absorption spectroscopy to gas sensing. The method we propose is incorporating plasmonic nanostructures with nano-composite material, metalorganic framework, which can selectively preconcentrate certain gas molecules into the nanopores. The preconcentrating property is first demonstrated by applying metal-organic framework...
RNA silencing pathways are required for a wide variety of processes in most
eucaryotes. In plants, small-interfering RNA (siRNA) arising from transposons and other
repetitive sequences is associated with heterochromatin formation and maintenance.
MicroRNAs and trans-acting siRNAs encoded at discrete loci function as negative regulators of
gene expression by triggering...
Drilled shaft foundations provide significant geotechnical resistance for support of structures, such as highway bridges, traffic sign, and signal pole structures, and are used widely to meet their structural foundation requirements. The amount of steel reinforcement in drilled shaft foundations has increased over the past several decades to account for...
Understanding the impact of inter-molecular orientation on the optical proper-ties of organic semiconductors is important for designing next-generation organic (opto)electronic and photonic devices. However, fundamental aspects of how various features of molecular packing in crystalline systems determine the nature and dynamics of excitons have been a subject of debate. Toward...
This thesis outlines the development of new elastomeric materials and manufacturing processes for soft robotics. Specifically, this work describes the development of custom material formulations for use in additive manufacturing, additive manufacturing processing techniques for silicone elastomers, and multi-component additive manufacturing techniques. Material synthesis and processing is a gap in...
Lower order, non-fish-bearing streams, often termed ‘‘headwater streams’’, have received minimal
research effort and protection priority, especially in mesic forests where distinction between riparian
and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is
higher in riparian zones, little is known about species distributions...
Social information is used widely in breeding habitat selection and provides an efficient means for individuals to select habitat, but the population-level consequences of this process are not well explored. At low population densities, efficiencies may be reduced because there are insufficient information providers to cue high-quality habitat. This constitutes...
Full Text:
Effects
in Breeding Habitat Selection
Kenneth A. Schmidt,1,* Jacob Johansson,2 and Matthew G. Betts3
1
Biodiversity information is made available through numerous databases that each have their own data models, web services, and data types. Combining data across databases leads to new insights, but is not easy because each database uses its own system of identifiers. In the absence of stable and interoperable identifiers, databases...
We measured activity levels of cesium radioisotopes ¹³⁴Cs and ¹³⁷Cs in wild edible fungi, mineral soil, and surface litter of the west coast of North America from southern California to northern Vancouver Island after the Fukushima nuclear accident. All activity measurements were below governmental limits for human health. ¹³⁷Cs activity...