We demonstrated a sensitive biosensor based on plasmonic metal composite nanostructures. The device can be fabricated and duplicated with ease using a novel nanoprinting technology which allows precise transfer of metal nanostructures without complicated lithography processes. The design featured by its unique material composition and sub-wavelength structures maximizes the exposure...
Lateral spread is a pervasive type of liquefaction-induced ground failure that occurs on gentle slopes or near free-faces, such as river channels. Resulting horizontal displacements can reach up to several meters, and can be considerably damaging to foundations, bridges, roadways, pipelines, etc. In the 1990s, Bartlett and Youd (1992a, 1995)...
The objective of this paper is to demonstrate a method for mechanically characterizing a 25 μm thick elastoviscoplastic hemodialysis membrane and for quantifying the force required to use that membrane in compression sealing. First, methods are developed for mechanically characterizing the thin elastoviscoplastic membrane. Then, a finite element model is...
Fischer-Tropsh Synthesis is a chemical process that converts CO and H₂ (syngas) into long stable hydrocarbon chains to use as fuel. This process suffers from large product distribution that requires expensive post processing. In this study, the reaction mechanism of hydrocarbon chain growth on Co is investigated on different surface...
The objectives of this research were to investigate the optimal conditions for anthocyanins extraction from different anthocyanin rich fruit and to develop microencapsulation formulation for improving stability of anthocyanin extracts. In the extraction optimization study, two extraction methods, "conventional solvent extraction (CE)" and "ultrasound-assisted extraction (UE)" for three different anthocyanin-rich...
The objectives of this study were to evaluate the physicochemical properties and bioactive compounds from four different types of fruit pomace, including apple, blueberry, raspberry, and cranberry, and further to investigate the feasibility of creating apple pomace based biocomposite boards using thermal compression molding and to optimize the biocomposite formulations...
In 2012, a university in the north western United States began offering a redesigned college algebra class that had a greater emphasis on active learning. Specifically, two out of four class periods were completely devoted to students working together in small groups on carefully designed worksheets. Two years later, the...
Transparent and electrically conductive metal oxide nanoparticles have attracted much attention, and can be used to improve the performance of solar cells, transparent electrode materials, and gas sensor technology. Specifically, indium tin oxide (ITO) nanocrystals (NCs) are potentially useful nanomaterials, having technological applications in enhanced sensitivity of optical spectroscopy due...
This thesis will explore the architectural material culture excavated at the Robert Newell Homestead (35MA41), currently located in Champoeg, Oregon. Specifically, the research focuses on the vernacular architecture or the features and construction methods used that both reflect the environment and the cultural traditions of the dwellings occupants. The Robert...
Assessing student conceptual understanding is a valuable method for gauging specific student learning outcomes but can be difficult and time consuming to measure. This research investigates the potential of automating some intermediary steps of a qualitative analysis of student conceptual understanding with tools from the field of Natural Language Processing...
Optical wireless communication (OWC) is an alternative to radio frequency (RF)communication with a signi cantly larger and unregulated spectrum. In OWC systems, optical orthogonal frequency division multiplexing (O-OFDM) with intensity modulation and direct detection (IM/DD) is commonly used. There are two common signal structures in most OWC systems based on...
Threshold-based time of arrival (TOA) estimation is a technique for high-precision indoor localization. Existing threshold selection methods, such as xed thresh- old and normalized threshold methods, do not consider the signal-to-noise radio (SNR) value at the receiver. This is not desired for high-precision positioning. A proper threshold value depends on...
The central Oregon coast was selected as an ideal site for wave energy
development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development...
Wheeled mobility devices (WhMD) pose unique safety risks to users while riding public transportation. Unsecured or improperly secured WhMDs create safety concerns for other transit riders and operators. Tests using accelerometers and visual observations were conducted to understand how WhMD orientation and securement in articulated buses, streetcars, and light rail...
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...
The low risk and sustainable implementation of nanotechnology requires understanding how nanomaterial physicochemical properties influence their toxicity. Major drivers of toxicity need to be avoided while maximizing product efficacy so nanomaterials can be produced to best serve their applications and be of low risk when intentionally or unintentionally released into...
Reports of foodborne outbreaks have increased in the last decade, posing a public health risk to consumers. In an attempt to mitigate this risk, the newly established Food Safety and Modernization Act (FSMA) takes a preventive rather than reactive approach to food safety. Under FSMA, producers are required to validate...
The Pacific Northwest produces over 95% of the nation’s processed red raspberries, valued at over $65 million. Two of the major soilborne pathogens effecting the production of raspberry in this region are the oomycete Phytophthora rubi, which causes root rot in red raspberry plants, and the plant-parasitic nematode Pratylenchus penetrans,...
Bees provide critical pollination services to diverse agricultural crops, native plants and trees. Globally, there are reports of bee declines which have been attributed to diseases, exposure to pesticides and changes in land use that are believed to have led to a reduction in foraging resources and nesting habitats for...
Entomopathogenic fungi are cosmopolitan microbial pathogens that cause fungous diseases in a wide range of insects via spore infection. Due to their natural enemy status, they have tremendous potential for use as microbial control agents against insect pests, especially subterranean pests for which few management options are available. The clover...
This thesis examines the effect of aerodynamics on Formula SAE cars. Due to the different objectives of the Formula SAE events, an understanding of the car's complete aerodynamic design is necessary. Using a half car computational fluid dynamics (CFD) model, a series of sensitivity studies are conducted to determine trends...
The mouth of the Columbia River (MCR) is an intersection of more than a river and ocean, but also multiple economically valuable activities including dredging to maintain a deep draft shipping channel and an active Dungeness crab (Metacarcinus magister) fishery. More than three million cubic meters of sediment are annually...
The Oaxaca Valley, located in the state of Oaxaca in Southern Mexico, was the site of the Zapotec civilization and its now famous capital, Monte Albán. This site, with political, military, and economic influence and control, helped to consolidate the three arms of the Oaxaca Valley, resulting in a state-level...
Nitrification is the process within the global Nitrogen Cycle where ammonia (NH3) is oxidized to nitrate (NO₃⁻) and can be carried out by two distinct groups of bacteria. The ammonia-oxidizing bacteria (AOB) first oxidize NH₃ to nitrite (NO₂⁻), and second, the nitrite-oxidizing bacteria (NOB) oxidize NO₂⁻ to NO₃⁻. In aerobic...
During the beginning of the postpartum period, 80 to 100% of lactating dairy cows have bacterial contamination within their uteri. Presence of uterine bacteria may contribute to increased number of days open and services per conception within these cows. Expulsion of uterine contamination is crucial for uterine involution and reproductive...
Two research projects comprise this thesis. The first project investigated modifying the hormone dosing strategy traditionally used in superovulating donor cows for an embryo collection to decrease drug costs without decreasing the number of high quality, transferable embryos recovered. The objective of this project was to evaluate the number and...
The purpose of this study is to measure and compare radiation emissions from flames burning large hydrocarbon fuels to assist in understanding how the molecular composition changes radiation emissions. Radiative heat transfer is significant because it is a primary mode of heat transfer for many combustion devices. This study also...
Over two million people experience homelessness in the United States, but homeless people are often marginalized by invisibility and stigmas surrounding poverty within their local communities. This research seeks to amplify the voices of Corvallis area homeless women as a means to understand their everyday lived experiences. Six women residing...
The cultivated potato, Solanum tuberosum L., has been one of the world’s most important food crops for more than 190 years and may become even more important to global food security in the coming 20 - 30 years. One of the world's largest growing health concerns is not just the...
Diabetes is a pandemic that affects nearly 29.1 million Americans and the fourth leading cause of mortality in the US. Type 1 diabetes is a chronic condition which occurs due to little to no production of insulin by the pancreas. This form of diabetes requires constant monitoring of blood glucose...
The thesis documents research about combining the National Pollutant Discharge Elimination System (NPDES) Permit Program with the Impact 2002+ methodology to conduct a Life Cycle Assessment (LCA) for wastewater treatment processes. The LCA for the operational phase of a local wastewater treatment plant was performed and the environmental impacts caused...
The Eastern California Shear Zone (ECSZ) is a broad zone of dextral shear inboard of the North American - Pacific plate boundary. Despite decades of study, the significance of a mismatch between geodetic velocities and geologic fault slip rates across the ECSZ remains incompletely understood. Geodetically determined interseismic strain across...
Loss of lowland estuarine and freshwater off-channel habitats along the Pacific Northwest coast has contributed to the decline of salmonid populations. These habitats serve as nursery grounds for juvenile salmonids providing them with food, winter shelter, and a transition zone between freshwater and saltwater. Lowland areas have undergone anthropogenic alterations...
Coastal sand dunes and beaches offer a variety of ecosystem services such as coastal protection, sand stabilization, species conservation, and recreation. However, the management and balance of ecosystem services offered by dunes and beaches is challenging when ecosystem services interact across the landscape. Management focusing only on one ecosystem service...
The fluid impact forces on a bridge superstructure in horizontal and vertical directions due to tsunamis represented by solitary waves are investigated through a large-scale laboratory experiment and numerical simulations. The experiment is conducted in a two-dimensional wave basin using a 1:5 scaled reinforced concrete bridge deck model tested under...
Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Evapotranspiration (ET) is the process by which water is transferred from land to the atmosphere. ET is the second most important component of a hydrologic budget and remains difficult to estimate. The primary objective of this project was to determine the limitations of estimating ET from water table elevation fluctuations...
This thesis details the applications of a new method of agent-based structure synthesis. The goal of this research is to create structures that meet a structural goal within a simulated physics environment. The method proposed works as an iterative process of changing the structure, evaluating the new structure and using...
In this thesis we study a numerical analysis problem motivated by the need to simulate an event such as an oil spill in a deep water environment. Numerical simulation can help to mitigate the disastrous effects of such events by aiding the management of risk assessment and recovery efforts.
However,...
Pacific salmon (Oncorhynchus spp.) face numerous challenges associated with climate change. Most research has emphasized the potential effects of elevated summer water temperatures; however, climatic changes are also projected to significantly alter incubation and rearing habitats during the late autumn, winter, and spring months ("the incubation period"). Along the southern...
Stevia (Stevia rebaudiana) is a perennial herbaceous plant native to Paraguay and used traditionally by the native Guarani peoples for centuries to sweeten medicinal teas. Stevia has only been commercially cultivated over the past 50 years and cultural practice information suitable for implementation by growers is limited. Currently stevia’s commercial...
The purpose of this thesis is to analyze an abrupt case of climate change in the past as a means to understand the mechanisms that force climate change. By looking to past analogs of climate change, we hopefully will gain an understanding of these events, which could be used to...
Feline injection site sarcomas (FISS) are frequently encountered cutaneous and subcutaneous neoplasms of cats. Significant patient morbidity is related to the invasiveness these tumors display, typically requiring extensive local excision or amputation. As with many veterinary tumors, survival time and tumor recurrence for FISS is highly influenced by histologic margin...
Signals from the R/V Langseth’s tuned airgun array were recorded on an array of 33 EarthScope FlexArray seismometers deployed in the Oregon Coast Range from 43.5° to 45°N as part of the 2012 Ridge2Trench experiment to image the structure of the Juan de Fuca plate. This segment of the Juan...
Background: Current policy in Oregon under the Individuals with Disabilities Education Act (IDEA) indicates that children diagnosed with developmental delay (DD) are eligible for services before school, but not eligible for the receipt of services in school-based programs. Due to this definition of eligibility, children with DD face additional barriers...
Involvement has been defined and researched by many student affairs professionals and theorists over the past 40 plus years. While many studies have researched the relationship between involvement and a student's academic success, little research has been done that explores what involvement means to them, and the motivations and factors...
The high-order finite element S[subscript N] transport equations are solved on several test problems to investigate the behavior of the discretization method on meshes with curved edges in X-Y geometry. Simpler problems ensured the correct implementation of MFEM, the general fi nite element library employed. A convergence study using the...
This qualitative study informed by a phenomenological approach explored the experiences of students when deciding to disclose bias-related incidents. Through an individual interview and follow-up focus group, eight participants shared their experience with bias-related incidents, decision to disclose or not to disclose, and perception of university resources. Five themes emerged...
Honey bees (Apis mellifera) are responsible for approximately $17 billion in crop production per year in the United States, and are arguably the most important pollinators in the nation. The future of crop pollination and production is threatened by widespread national honey bee colony losses, which have averaged approximately 30%...
This thesis describes how heteropatriarchal, settler colonialism impacted Indigenous communities' systems in power and control, particularly with the American Indian Movement during the 1960s-1970s. Further, the gendered divides this created within the American Indian Movement are described. The murder of Anna Mae Aquash is revisited as an act of gendered...