Previous research has shown that using fine lightweight aggregate (FLWA) can be a promising strategy to mitigate alkali-silica reaction (ASR) in mortar and concrete. While several possible theories were proposed by researchers, discrepancies in testing methods, materials, and supporting evidence still exist. Therefore, this study was initiated. There are two...
The Utah System of Higher Education (USHE) and the eight public colleges and universities in the system, have depended on the Federal Pell Grant program for more than 40 years to assist students to attend. For some of these institutions, the amount of Pell grant dollars received is as much...
Detection of xenon radioisotopes (radioxenons) has proven to be an important method for detecting nuclear explosions and is particularly well suited for detecting undeclared underground testing. The radioxenon isotopes ¹³¹mXe (t₁/₂ = 11.934 d), ¹³³mXe (t₁/₂ = 2.19 d), ¹³³Xe (t₁/₂ = 5.243 d) and ¹³⁵Xe (t₁/₂ = 9.14 h)...
This dissertation presents a phase domain in-loop-bandwidth spread-spectrum clock generation technique. In this proposed technique, a charge-based discrete-time loop filter is proposed to enable the phase domain in-loop-bandwidth spread-spectrum modulation without a delta-sigma modulator or time-to-digital converter. The in-loop-bandwidth modulation technique maximizes the loop bandwidth to improve phase noise suppression...
Phytoplankton are a sentinel class of organisms in the marine environment. Through their photosynthetic activity in sunlit waters worldwide, phytoplankton shape the health and productivity of marine ecosystems and impact the global climate. In this work a range of ocean sensing technologies (via ships, surf zone sampling, moorings, gliders, and...
Irrigated agriculture constitutes the greatest consumptive water use globally, so that irrigation efficiency measures are an important part of global efforts to best utilize this limited resource. However, greater irrigation efficiency must be achieved while simultaneously maintaining or increasing crop yields and farming profitability. Incremental water use decisions are made...
Limnology is undergoing a transition to high-throughput -omic analysis of freshwater
bacterial communities. An important first step in making the transition is to
characterize several genomes that can be used as references to guide metagenome
assembly and analysis. Here I characterize four new freshwater cyanobacterial
genomes, a pair of lake...
Background: African American males' experience in higher education is often categorized with negative terminology that does not reflect notions of success. Most research addressing the success of African American males in higher education illuminates factors that impede access to success and is often situated in university settings. Very little research...
High-energy delayed γ-rays from photofission were demonstrated to be signatures for detection and identification of special nuclear materials. Such γ-rays were measured in between linac pulses using independent data acquisition systems. A list-mode system was developed to measure low-energy delayed γ-rays after irradiation. Photofission product yields of ²³⁸U and ²³⁹Pu...
The implementation and construction of Mechanically Stabilized Earth (MSE) walls has undergone substantial expansions in recent years, owing to its relatively low cost, ease of construction, and high efficiency compared to conventional retaining methods. As a result, MSE walls are being constructed to greater heights with complex features (e.g. multiple...
Atmospheric pressure changes do not stop at the permeable snow surface but rather propagate into it. These pressure changes range from high-amplitude, low-frequency events caused by seasonal cycles and synoptic weather systems to small-amplitude, high-frequency events caused by topographic features and turbulence. The effect of pressure changes on interstitial air...
The purpose of the dissertation was to gain an understanding of variables that influence the psychosocial health of Asian American college students. There is sufficient literature support indicating this population experience greater levels of intrapersonal and interpersonal distress compared to non-Asian peers, and the significant role of family in their...
Two indigenous species of burrowing shrimp inhabit and often dominate the intertidal zone of estuaries along the US West Coast, the ghost shrimp, Neotrypaea californiensis, and the blue mud shrimp, Upogebia pugettensis. Both species are considered ecosystem engineers and play a role in maintaining estuarine health and ecosystem function. They...
This dissertation uses argon geochronology and cosmogenic nuclide surface exposure dating methods to address three research questions. The first question concerns a geomagnetic instability recorded in lava flows on the island of Floreana in the Galapagos Archipelago. Changes in the Earth’s magnetic field (intensity and orientation) occur frequently throughout geologic...
Soils and other resource programs in both public land management agencies and private industry are continually being adapted to the challenges of evolving knowledge and experience in the field of forestry. This dissertation explores new ways of thinking about and using soils information in forest planning and management, with a...
It is uncertain how predicted changes in climate will impact vegetation responses and plant species’ distributions because the physiological mechanisms underlying thresholds for damage are not well understood, and responses to stress vary by functional type and developmental stage. Thus, it is crucial to investigate physiological responses to heat and...
Recent state and national standards have increased the interest in engineering at the K-12 level. Science standards, in particular, have begun to make the case for including engineering throughout the K-12 scope of study. Despite the increased attention to engineering, the characteristics and uniqueness of the field of engineering are...
Numerical models are effective tools for simulating complex physical processes such as hydrodynamic and water quality processes in aquatic systems. The accuracy of the model is dependent on multiple model parameters and variables that need to be calibrated and regularly updated to reproduce changing aquatic conditions accurately. Multi-sensor water temperature...
Although only a minority of introduced species become established and have noticeable consequences in their new communities, some can displace native species, alter food webs, and cause local extinctions. Studying these invasive species can provide new insights into basic ecological questions as well as inform management strategies. Pacific lionfish (Pterois...
There are presently two successful methods used to refine fish muscle proteins: surimi and fish protein isolate (FPI). Both surimi and FPI have the ability to form an elastic gel upon comminution and heating. However, their gelation behaviors are different as they are refined in a biochemically opposite way based...
Researchers rely on bioeconomic models to guide research and generate fishery management advice for commercial fisheries. Due partly to a paradigm shift towards ecosystem based fishery management, increasing complexity in the characteristics of the problems has meant that bioeconomic simulation models are becoming more prevalent in the fisheries literature. However...
We are at risk of losing the sagebrush steppe in the floristic Great Basin to the invasion of Bromus tectorum L., cheatgrass. The floristic Great Basin includes the Central Basin and Range, the Northern Basin and Range, and the Snake River Plain. The Great Basin receives most of its precipitation...
Brown marmorated stink bug (BMSB), (Halyomorpha halys, Hemiptera: Pentatomidae) is an invasive species that damages numerous agricultural crops including grapes. Related damage include lower berry weight with increased exposure and cracked berries as a result of BMSB feeding activity. The insect is currently detected in 43 US states including Oregon,...
There has been a tremendous growth in interest in carbon nanodots (C-dots) in the past several years. As a nascent nanomaterial, C-dots have shown great promise in applications that benefit from their superior water dispersibility, low toxicity, non-blinking fluorescent output, chemical and biological compatibility, ease of functionalization and resistance to...
This dissertation addresses gaps of knowledge associated with how ecosystem carbon stocks and greenhouse gas emissions are affected by land use land cover change in tropical peatlands. This was the first study that paired peat swamp forests with oil palm plantations and analyzed site scale variation on greenhouse gas emissions....
The purpose of this case study is to explore a mentoring program designed for African American male community college students at a Pacific Northwest community college. Community college practitioners can use the knowledge gained from this study as a best practice to increase the persistence and success of African American...
In this dissertation, I describe the experimental investigation of catching ions in superfluid helium droplets. The ultimate goal of our project is to build a coherent electron diffraction apparatus for atomic structure determination from oriented single macromolecules. This involves generating protein ions from electrospray ionization (ESI) and doping them in...
This dissertation serves as a contribution to the study of the prehistory of the Central Desert region of Baja California, Mexico. Between 2007 and 2011, a trans-peninsular archaeological survey and excavation program―the Central Desert Early Prehistory Project (CDEPP)―was completed for a portion of the Baja California peninsula extending from the...
The multifaceted role of the environment in regulating the structure and dynamics of biological communities has long fascinated ecologists and motivated much debate and research. Now, in a time of accelerated global changes due to human impacts, the need to understand how the environment shapes communities has gained new urgency....
The Next Generation Science Standards (NGSS) are a recent set of standards that leverage decades of research to present an innovative and coherent image for K 12 science education in the United States. Major themes in the NGSS include the intertwining of learning and doing science, addressing connections across scientific...
The sexually transmitted disease gonorrhea, caused by the Gram-negative bacterium and obligate human pathogen Neisseria gonorrhoeae, remains a significant health and economic burden worldwide. In the absence of a protective vaccine, antimicrobial agents are the only pharmacological intervention for patients with gonorrhea. However, due to the remarkable ability of gonococcus...
The transition of mature pollen to the progamic phase represents an important step in the regulation of plant sexual reproduction. The progamic phase encompasses the initiation of pollen tube germination, growth of the pollen tube through the stigma (the silk in maize) and concludes with fertilization of the female gametophyte....
Hearing loss is one of the most common defect, affecting 360 million people worldwide due to several factors including congenital, present at or soon after birth or acquired with age. Congenital hearing loss affects 32 million children in the world. The economic impact of hearing loss is estimated to cost...
Piezoelectric materials convert mechanical strain into a dielectric displacement, as well as the converse, allowing these materials to be used as sensors, actuators, and transducers. Currently, lead zirconate titanate (PZT) is the primary material used in these applications. Due to environmental toxicity and safety concerns associated with Pb, development of...
Chlamydia is a genus of obligate intracellular bacteria that undergo a unique, biphasic developmental cycle. The infectious and metabolically inert Elementary Bodies (EBs) begin the cycle of infection by attaching and invading a host cells. Once inside, the EBs differentiate into the metabolically active, dividing Reticulate Bodies (RBs) within their...
There are more than 87,000 chemicals in current use with little to no toxicity information available. Assessing such a large number of chemicals using traditional methods would take an unreasonable amount of time and money, and require the use a large number of animals. The incorporation of high-throughput in vivo...
Global warming is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Creating useful applications for CO₂ would generate alternatives to merely venting CO₂ to the atmosphere, and decreasing the carbon intensity of human activities. Among various methods of CO₂ utilization, conversion...
The advent of improved DNA sequencing technologies has allowed the analysis of various microbial communities. Bloom-forming freshwater cyanobacteria can produce toxins and taste-and-odor compounds that can negatively affect drinking water supplies. Here, I have employed second- and third-generation sequencing technologies to characterize bloom-forming freshwater cyanobacterial genomes and their associated heterotrophic...
In this thesis we construct compatible discretizations of Maxwell's equations. We use the term compatible to describe numerical methods for Maxwell's equations which obey many properties of vector Calculus in a discrete setting. Compatible discretizations preserve the exterior Calculus ensuring that the divergence of the curl and the curl of...
The state of Oregon is divided in important ways along rural and urban lines, including the way people make a living, individual and group relationships with the natural world, political ideologies, and personal values. This rural-urban divide has assisted policymakers in making decisions that balance the needs of Oregonians on...
This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
The purpose of this dissertation was to add to the professional literature in counselor education and supervision through inquiry and synthesis of research among online teaching, online counseling, and online communities of practice through the supervision lens of the Discrimination Model. A unique, research-informed framework for synchronous online supervision (i.e.,...
The aim of this research is to develop a fundamental understanding of the dominant defect species and the relevant defect equilibrium conditions for bismuth-containing perovskites to help guide the development of these materials for emerging applications. This is of paramount importance for many demanding applications, because ultimately the defect equilibria...
An enabling technology for long duration, deep space missions is the availability of a high power, long-lived power supply. The goal of this work is the design of a self-regulating deep space nuclear reactor. The design objectives are to produce 250 kWth for a 25-year period using the presence of...
The rapid scaling of network bandwidth and data center throughput has motivated the wide adoption of high speed transceivers. Silicon photonics (Si-Photonic) is one of the most promising techniques to realize tightly integrated optical transceivers for next-generation high speed I O standards. This dissertation focuses on the design techniques of...
This dissertation consists of a set of three manuscripts exploring features of effective professional development (PD) for science teacher educators. Literature about context-specific PD for science teacher educators is sparse. The first manuscript, a literature review, outlines theoretical lenses through which PD can be understood, the features of effective PD,...
Today nano scale materials are being used for wide range of applications. One promising topic in nano scale materials is using them for reinforcement of different polymeric materials to reach desirable stiffness properties. The stiffness of these materials is mostly found experimentally because the nanocomposite community lacks a decent analytical...
The National Research Council has aggregated research evidence on the pedagogy of science teaching and learning (NRC, 2012), culminating in the Next Generation Science Standards (NGSS). These standards support emphasis on eight scientific practices as an important component for teaching science as inquiry to K-12 students. This latest framework for...
Research on the population genetics of microbial organisms requires the use of specialized analyses designed for clonal organisms to avoid violating the assumptions of traditional population genetic models. The tools necessary for performing these analyses existed as a set of unrelated software with non-overlapping capabilities and did not cover all...
A system for radiological dosimetry for nonhuman biota developed by International Commission on Radiological Protection (ICRP) relies on calculations that utilize the Monte Carlo simulations of simple, ellipsoidal geometries with internal radioactivity distributed homogeneously throughout. In this manner it is quick and easy to estimate whole-body dose rates to biota....