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...
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...
Acquired Immune Deficiency Syndrome (AIDS) has become the world's foremost health threat and is the number one killer in Zimbabwe. Acquired Immune Deficiency Syndrome impacts not only the individual who has AIDS, but on nuclear and extended families, and all aspects of society in Zimbabwe. Since studies have indicated that...
Following the work of Asai, Kaneko, and Ninomiya for Faber polynomials associated to the modular group, and Bannai, Kojima, and Miezaki's partial proof for the case of the Fricke group of level 2, we show that the zeros of certain modular functions for some low-level genus zero groups associated to...
In this dissertation, we begin by presenting the result of F. K. C. Rankin and Swinnerton-Dyer on the location of the zeros of the Eisenstein series for the full modular group in the standard fundamental domain. Their simple but beautiful argument shows that all zeros are located on the lower...
In this dissertation, I present electronic spectra of a few polycyclic aromatic hydrocarbons (PAHs): tetracene, pentacene, pyrene, benzo[g,h,i]perylene and benzo[a]pyrene using resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The work of tetracene and pentacene also combine a laser desorption source with a ZEKE spectrometer, demonstrating...
In this dissertation, I describe spectroscopic studies of jet-cooled polycyclic aromatic hydrocarbons (PAH) and one nitrogen substituted PAH (PANH) using pulsed field zero kinetic energy (ZEKE) photoelectron spectroscopy and resonantly enhanced multiphoton ionization (REMPI) spectroscopy. Recently, there has been a demand for far-infrared (FIR) spectral information of astrophysically relevant molecules...
Academic success is a salient domain of youth development and is related to positive lifelong outcomes among youth in foster care. However, youth in foster care experience compounding adversities, including maltreatment and foster care placement itself, which put them at risk of academic disengagement and underachievement. Despite these adversities, academic...
During the first full school year of the Covid-19 pandemic, two central contexts for adolescent development—home and school—changed utterly. In Oregon, most middle- and high schoolers attended school entirely remotely from the beginning of the pandemic, in March, 2020, through the end of April, 2021, removing both the supports available...
In 2008, the “Great Recession” gained its momentum and quickly grew into a global crisis that led to massive gross domestic product declines and job losses in countries around the world. Relative to prior economic downturns, young adults were greatly affected by the Great Recession. This likely placed a premium...
Human alterations of landscapes take many forms, one of which is anthropogenic pollution. Mercury (Hg) is a complex contaminant because its uptake into the food web is not driven entirely by loading to the system; methylation is necessary to make Hg bioavailable and toxic to fish and wildlife. Because methylation...
This dissertation describes patterns in epiphytic macrolichen community composition along a nitrogen deposition gradient in the Yosemite region of the Sierra Nevada in California. This region is part of the largest federal air quality Class 1 designated air-shed in the western United States, covering the entire crest of the Sierra...
Several dolphin species have global distributions. The extent of their radiation and limits to gene flow are presumably a product of oceanographic features both recent and historical, behavioral specializations and social organization. Rough-toothed dolphins (Steno bredanensis) are globally distributed in tropical and subtropical waters and are generally found in depths...
The purpose of this study was to identify and describe the underlying mechanisms within community colleges that influence cross-functional collaboration. The study also explored the role of community college leadership in fostering internal collaboration. The following questions guided the research: (1) What does cross-functional collaboration look like at a community...
Improvement behaviors, specifically double loop, have been linked to successful lean implementations. Although the lean literature supports individual cognitive transformation to double loop learning as an important element of lean success, there remains a strategic methodology to achieve sustainable double loop behavior. Perceptions toward behavior and employee satisfaction have been...
There is no doubt that adhesive penetration plays an important role in wood bondline joint performance and durability; yet, to date there is no direct experimental evidence linking penetration depth with bond performance. This is, in part, because adhesive penetration is commonly assessed with various 2D microscopy techniques that are...
There are a number of wood properties which affect the quality of forest products such as lumber and pulp. Of these, wood density is considered by some to be the single most important physical characteristic because it is an excellent predictor of strength, stiffness, hardness, and paper-making capacities. Accurately assessing...
The purpose of this study is to critically explore low-income women's experience as they negotiate post secondary education in community colleges. Three research questions explore the context through which low-income women have entered the college experience, what that experience is like for them, and how the community college experience has...
Generally presented as a preferred social norm based on both ethical considerations and legislative demands, gender equality has been highly encouraged in recent years. For instance, The United Nations Sustainable Development Goals for 2030 call out achieving gender equality and empowerment of women. However, although there are multiple efforts to...
An interpretative philosophical framework was applied to a case study to document the particular experiences and perspectives of ten women engineering transfer students
who once attended a community college and are currently enrolled in one of two university
professional engineering programs. This study is important because women still do not...
The dominant narrative of U.S. Muslims in higher education is associated with violent rhetoric, anti-American values, and terrorism. After terrorist attacks took place on September 11th, 2001, this narrative expanded to include a depiction of U.S. Muslims as being oppressed and submissive. Hate crimes, discrimination, and Islamophobic attacks towards Muslims...
The prevalence of Internet-of-Things (IoT) applications leads to an increasing focus on the design and optimization of sensor nodes. Battery lifetime and associated costs of battery replacement often limits the long term operation and viability of sensor nodes. RF wireless energy harvesting on the other hand can be appealing since...
This dissertation studies two different wireless microwave sensing applications in the subjects of environmental monitoring and biomedical devices. The environmental sensing application presents a design of novel wireless sensor node configurations. These nodes are intended to be used specifically in a built environment of railroad track ballast for its health...
The southwest monsoon, which may be idealized as the northward movement of the intertropical convergence zone in the Indian Ocean associated with differential heating of land and ocean, brings a seasonal reversal of currents and winds in the Bay of Bengal and the Arabian Sea. Atmospheric convection from monsoon activity...
With continual and worldwide human population growth, our impact on the natural environment expands and intensifies every day. We consume natural resources, burn fossil fuels, and release toxic compounds into the air, water, and earth. We build roads that fragment the landscape, construct new settlements, and develop agricultural lands in...
In this dissertation, I examine how the spatial configuration of forest ownership influences the risk-mitigating behavior of public and private forestland owners over time. I determine whether or not the predicted equilibrium outcomes are socially optimal and, if not, whether the introduction of regulation, liability, or private insurance would lead...
Low-distortion architecture is widely used in wideband discrete-time switched-capacitor delta-sigma ADC design. However, it suffers from the power-hungry active adder and critical timing for quantization and dynamic element matching (DEM). To solve this problem, this dissertation presents a delta-sigma modulator architecture with shifted loop delays. In this project, shifted loop...
Nowadays, needs for wideband and high accuracy analog-to-digital converter are increasing rapidly in manifold applications such as wireless communication, digital video and other consumer electronics. Besides, low power consumption is required to have longer battery life in portable systems. CMOS technology scaling and innovative modulator topology make the implementation much...
There is a significant need in recent mobile communication and wireless broadband
systems for high-performance analog-to-digital converters (ADCs) that have wide
bandwidth (BW>5-MHz) and high data rate (>100-Mbps). A delta-sigma ADC is
recognized as a power-efficient ADC architecture when high resolution (>12-b) is
required. This is due to several advantages...
The work presented here is focused on applying basic principles of solid-state chemistry to the study and development of new wide band-gap semiconductors and insulators for photovoltaic and electronic-device applications. Analysis of crystal structure, band structure, optical band gap, morphology and transport properties provides fundamental insight into materials performance as...
Legumes are defined as the immature, germinated, or mature edible seeds of legume plants (Fabaceae). The primarily consumed legumes are dry beans, dry peas, lentils, chickpeas, cowpeas, fava beans, and pigeon peas, which are grouped as mature legumes, green beans and peas, which are considered green legumes, and sprouted or...
The purpose of this study was to explore motivations behind participation in cosplay and the use of social media among cosplayers who maintain Facebook Artist Pages. Further focus was placed on investigating the role of Facebook Artist Pages in building fame. To explore such motivations, two theories were referenced: Deci...
Rural farmers in Tanzania depend on subsistence agriculture for their livelihood. Poor soil conditions, and the danger of drought, increases the risk of cyclical poverty conditions. Aid organizations, including the World Agroforestry Centre (ICRAF) and the Millennium Development Projects (MDP), as well as industrial tobacco industry, have provided development programs...
This research examines two questions: 1) What stories do Christian teacher educators tell about their own White racial identity development? and 2) Is there an impact of studying White racial identity development on the praxis of Christian teacher educators? If so, in what ways? The researcher began the project with...
The purpose of this qualitative study was to examine the experience of white principals in understanding their white identity, privilege, and power as they worked to implement socially-just and culturally proficient schools. The findings offer insights into the following questions: 1) How do white school leaders view white identity and...
The Newell Farmstead (35MA41) archaeological site lies in the heart of the French Prairie in the Willamette Valley in the Champoeg State Heritage Area, Oregon. The integrity and depth of deposition have made the Newell site a unique opportunity to look at activity areas and domestic life of early Euro-American...
Affective reactions to daily stressors are known mechanisms through which daily stressors impact health and well-being (e.g., Charles et al., 2013; Piazza et al., 2013; Sin et al., 2015; Stawski et al., 2019). Therefore, understanding what may promote resilience or vulnerability to such affective reactions is imperative. Theoretical perspectives (Almeida,...
This dissertation for the degree of Doctor of Philosophy in Public Policy addresses two main research questions. On a macro-level it aims to answer how gender ideologies, as seen in attitudes towards the gendered division of labor, develop over time in the context of changing family policy regimes. On a...
This study proposed a theoretical model of choice overload and empirically examined the model in the context of online apparel shopping. The purpose of the study was to investigate how the number of choices and product presentation formats influenced consumers’ online apparel shopping experience as well as how the formed...
This dissertation has focused on lignin byproducts that result from the alkali processing of wheat straw. The first study evaluated the application of “standard” lignin quantification methods for summative analyses of alkali-based processes. Mass closure during NaOH processing at 25, 50, and 75°C of wheat straw was evaluated using the...
Wheat is a staple food crop with many applications. The composition and quantity of major and minor flour components greatly influence functional dough properties, processing quality, and end-use suitability. Seven to 15% of the weight of wheat flour is protein and the gluten proteins comprise 80-85% of that. The gluten...
Urban African American adolescents exhibit high levels of risk behavior, disproportionately high rates of sexually transmitted infections (STIs), and are at risk for acquiring Human Immunodefiency Virus (HIV). To date, interventions that address the high rates of STIs in this population demonstrate only moderate efficacy. As researchers strive to develop...
The myxozoan Ceratonova shasta is an intestinal parasite of salmon and trout that causes ceratomyxosis, a disease characterized by severe inflammation of the intestine that can lead to hemorrhaging, necrosis, and death of the fish host. The parasite is endemic to the Pacific Northwest of the United States and Canada,...
Near-surface advanced argillic hydrothermal alteration zones, also referred to as lithocaps, are characterized by quartz, alunite, clays (pyrophyllite and kaolinite group minerals), and minor F-bearing aluminosilicates (i.e., topaz, zunyite, diaspore, and APS) that form where water-, SO2-, and HF-rich gas condenses into shallow groundwater, acidifies, and reacts with rocks. The...
Corals have multiple roles in maintaining ocean health and are some of the world’s most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host...
Issues of injustice in society (e.g. racism, classism, sexism, ableism) are perpetuated in and through educational opportunities, including mathematics learning (Freire, 1970/2000). Those that are committed to disrupting the interlocking systems that create disparities and oppression in mathematics education are considered to be “pursuing justice.” Pursuit of justice can involve...
A widely held belief is that the pre-2018 U.S. repatriation tax has led to stockpiles of cash of multinational corporations being trapped overseas, but there is evidence showing that firms are issuing debt to access cash. Standard and Poor has documented this phenomenon as “synthetic cash repatriation.” This study examines...
Nonalcoholic fatty liver disease (NAFLD) is characterized by an accumulation of neutral lipids in the form of triglycerides and cholesterol esters accounting for >5% of liver weight. Excess neutral lipids accumulate in large lipid droplets, i.e., macrosteatosis, displacing the nucleus of cells. Current theory suggests neutral lipid accumulation is the...
West Nile Virus (WNV), a vector-borne disease continues to be a serious threat to public health in the United States, particularly in the Southwest region. While all the states in the U.S. experienced a decreasing trend of WNV disease in 2010, the state of Arizona experienced a sharp increase from...
The publicly subsidized Federal Crop Insurance Program has expanded rapidly in recent decades in the United States. With the reform in the 2014 Farm Bill, the Federal Crop Insurance Program has become the most important component of U.S. farm policies. The primary goal of the program is to provide risk...