Digital Commons Network^™

Darboux Integrability Of Wave Maps Into 2-Dimensional Riemannian Manifolds, Robert Ream

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The harmonic map equations can be represented geometrically as an exterior differential system (EDS), ε. Using this representation we study the harmonic maps from 2D Minkowski space into 2D Riemannian manifolds. These are also known as wave maps. In this case, E is invariant under conformal transformations of Minkowski space. The quotient of ε by these conformal transformations, E/G, is an s=0 hyperbolic system.

The main result of our study is that the prolonged EDS, ε^(k), is Darboux integrable if and only if the prolonged quotient EDS, ε^(k+1), is Darboux integrable. We also find invariants determining …

Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …

Development Of Modular Thermal Control Architecture For Modular Satellites, Quinn Eric Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research has been completed to determine the most effective thermal control architecture for modular satellites. This research investigated principles of modularity, modular spacecraft examples, thermal control methods, and advanced thermal control technologies. A modular spacecraft was designed as a case study to determine key influences and issues. A number of thermal control architectures were developed. Each was evaluated for compatibility with modularity principles, thermal control performance, and a realizable implementation. Thermal control performance was determined by simulating on-orbit conditions for a number of design reference missions, including traditional thermal control architecture used for comparison. An effective thermal control architecture was …

Distributed Control For Robotic Swarms Using Centroidal Voronoi Tessellations, Shelley Rounds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis introduces a design combining an emerging area in robotics with a well established mathematical research topic: swarm intelligence and Voronoi tessellations, respectively. The main objective for this research is to design an economical and robust swarm system to achieve distributed control. This research combines swarm intelligence with Voronoi tessellations to localize a source and create formations. Extensive software coding must be implemented for this design, such as the development of a discrete centroidal Voronoi tessellation (CVT) algorithm.

The ultimate purpose of this research is to advance the existing Mobile Actuator and Sensor Network (MASnet) platform to eventually develop …

School-Based Services For Children With Attention-Deficit/Hyperactivity Disorder, Tonya M. Tree

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was designed to present descriptive data from a survey of 201 school psychologists. Psychologists completed a survey addressing current practices for determining placement for students with ADHD including the role of school psychologists in determining placement, how often and who monitors services, where students are served, and what services are provided in each setting. Findings indicated that psychologists were involved less frequently in placement decisions and evaluation for Section 504 than in Special Education. Students with 504 plans received less frequent follow-up than students in Special Education. Results indicated that schools were generally following federal guidelines and recommendations …

Evaluation Of Arrayed-Field Concentration Measurements And U. S. Epa-Regulatory Models For The Determination Of Mixed-Source Particulate Matter Emissions, Derek Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the continued population growth and the blurring of the urban and rural interface, air quality impacts associated with agricultural particle-producing processes are becoming increasingly important. There is a lack of emission rate data from these source types and no prescribed measurement technique available to the agricultural and regulatory communities. One technique that has shown promise is combining field measurements with inverse modeling. This approach was used herein to examine particulate emissions from an almond harvesting operation, a cotton ginning facility, and comparative emissions from conservation versus conventional tillage practices. EPAapproved models ISCST3 and AERMOD were used with AirMetrics samplers. …

Perceived Crowding And Visitor Support For Use Rationing: A Reanalysis Of Existing Data, Jascha M. Zeitlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a reanalysis of data collected between 1999 and 2006 by the Institute for Outdoor Recreation and Tourism (IORT) at Utah State University. These data concern a variety of outdoor recreation sites in Utah, Idaho, and South Dakota, and were collected via intercept, mail, and, to a very limited extent, telephone surveys. Survey instruments contained questions related to visitor perceptions of crowding, overall satisfaction, support for use limits/rationing, and estimates of use density, in addition to other conceptually related factors.

Analyses consisted of multiple regression models for both perceived crowding and visitor support for use limits dependent variables …

The Effect Of Teacher Education Level, Teaching Experience, And Teaching Behaviors On Student Science Achievement, Danhui Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous literature leaves us unanswered questions about whether teaching behaviors mediate the relationship between teacher education level and experience with student science achievement. This study examined this question with 655 students from sixth to eighth grade and their 12 science teachers. Student science achievements were measured at the beginning and end of 2006-2007 school year. Given the cluster sampling of students nested in classrooms, which are nested in teachers, a two-level multilevel model was employed to disentangle the effects from teacher-level and student-level factors. Several findings were discovered in this study. Science teachers possessing of advanced degrees in science or …

Evaluation Of An Interactive Health Communication Trans Fat Website, Tara Banks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to evaluate the short-term educational and behavioral impact of the American Heart Association's "Face the Fats" web application had upon college students, a study involving 116 Utah State University undergraduate students was conducted. A one-group pre-posttest design was utilized to answer eight research questions focusing on: health risks associated with trans fat, general trans fat knowledge, ability to identify foods containing trans and saturated fats, food label information, healthy alternatives to trans fat, and readiness to change trans fat intake. Participants completed an online pretest survey and then viewed the "Face the Fats" website at their own pace. …

Experiments In Distributed Multi-Robot Coordination, Larry Dale Ballard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consensus control algorithms for multi-agent systems are an area of much research. Several consensus control laws are experimentally validated on a multi-robot testbed in this thesis. A graphical user interface (GUI) is developed that simplies use of the testbed, as well as allows the execution of the testbed programs to be divided across multiple computers. This not only provides a more powerful computing environment, but a more realistic communication environment for the testbed. A method for a time varying or dynamic formation is both proposed and experimentally validated on the testbed. This research also explores a method for dynamic group …

The Adaptability Of Langmuir Probes To The Pico-Satellite Regime, Andrew Jay Auman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to investigate whether it is feasible to use Langmuir probes on pico-satellites flying in low Earth orbit over mid- to low-latitude geographic regions. Following chapters on the expected ionospheric conditions and an overview of Langmuir probe theory, a chapter addressing the difficulties involved with pico-satellite Langmuir probes is presented. Also, the necessary satellite-to-probe surface area requirements in order to achieve confidence in pico-satellite Langmuir probe data, for the orbital regions of interest to this thesis, are stated.

Threat Perception As A Determinant Of Pro-Environmental Behaviors: Public Involvement In Air Pollution Abatement In Cache Valley, Utah, Joshua D. Marquit

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Threat perception related to environmental issues such as air pollution may be a determinant of pro-environmental behaviors. Among the potential threats of air pollution, include the perceived impacts on the psychological, social, and economic wellbeing of a community. Because of rapid increases in population growth, urbanization, and the mountainous landscapes, the American West is extremely susceptible to the adverse impacts of air pollution.

A secondary data analysis was conducted using data from the Air Quality Perception Survey conducted in Cache County, Utah. The survey focused on the public perception of air pollution in Cache County and perceived impact on personal …

Mother-Child Interactions Among Latino Families And European-American Families In Relation To Children's Language Outcomes, Katie Christiansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The number of Latino families in the United States is increasing dramatically. For some of the children in these families, the acquisition of reading skills is hampered by inadequate early language development. Early language development is a key predictor of reading success. Identifying ways in which parents in these families can help children acquire early language skills will better prepare them for acquiring reading skills.

This study used a new parenting measure, PICCOLO, to identify parenting behaviors that are related to children's language development. The primary focus of this project was on Spanish-speaking Latino families, but a group of English-speaking …

Synthetic Complexes Of Relevance To Ni(Ii)-Containing Enzymes, Katarzyna Rudzka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work outlined herein presents an investigation of synthetic model complexes of relevance to the active sites of Ni(II)-containing enzymes, particularly urease, glyoxalase I, and acireductone dioxygenase. The research focuses on studying the structural and reactivity features of nickel complexes with biologically relevant substrates. The anion of acetohydroxamic acid is a well-known inhibitor of urease enzymes, including those isolated from Klebsiella aerogenes and Bacillus pasteurii. A precursor to the acetohydroxamate coordination in ureases is proposed to be an interaction between Ni(II) and acetohydroxamic acid. By using a novel supporting chelate ligand capable of secondary hydrogen bonding interactions a novel …

Extending F10.7'S Time Resolution To Capture Solar Flare Phenomena, Ariel O. Acebal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar ultraviolet (UV) radiation ionizes the neutral components in the atmosphere, which is partly responsible for the formation of the ionosphere, and contributes to heating of the atmosphere. Solar flares change the solar spectrum at times by several orders of magnitude. These changes modify the Earth's upper atmosphere, causing problems to communication systems and space operations, such as increased satellite drag. Unfortunately, solar UV measurements are limited since they can only be observed with space-based sensors. In order to work around this limitation, the solar radio emissions at a wavelength of 10.7 cm have been used as a proxy for …

Retirement Savings And Types Of Investment Assets Among Near-Retirees Aged 51-64: How Do Women Invest Differently Than Men?, Katrina R. Nye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine the financial portfolios of near-retiree women and compare their assets to near-retiree men. This study also investigated how economic and demographic factors were associated with the probability of holding aggressive assets and the level of savings. Socioeconomic variables were used to create a profile of the investment behaviors and to examine the level of savings among near-retiree women and men. Specific variables key to the study included household income, age, marital status, education, race, and self-reported health of near-retiree women and men.

The descriptive statistics indicated that overall, average levels of all …

Air Demand In Free Flowing Gated Conduits, David Peter Oveson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A physical experimental setup of a circular, gated closed conduit was built at the Utah Water Research Laboratory (UWRL). Setup configurations were modified and data were measured to aid in the study of physical variables on air demand. It was determined that gate opening, gate and water surface roughness, and conduit length all were significant variables on the air demand measured through the conduit air vent. It was also determined that no noticeable air velocity profile existed above the air-water interface. A linear relationship was found between the air flow rate to water flow rate ratio (air-demand ratio) and head-to-gate …

Analysis Of Effectiveness Of Bridges With Partial Isolation, Wenying Hu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A special class of seismically isolated bridges shares a common feature in that both ends of the superstructure are restrained and isolators over the columns of bridge uncouple the superstructure from the ground motions. They are defined as partial isolation bridges. From measured acceleration responses, effectiveness of full seismic isolation had been confirmed widely. However, the seismic isolation behavior in the partial isolation has not been widely observed.

The effectiveness of partial isolation is evaluated in this study. The static design procedures for linear and nonlinear partially isolated bridges are developed. Results from the static analysis of linear and nonlinear …

The Impact Of Religious Schema On Critical Thinking Skills, Matthew Kirby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine the relationship between critical thinking and religious schema as represented by religious orientation. Past research has included religious belief within the larger construct of paranormal belief, and demonstrated a correlation between high levels of paranormal belief and poor critical thinking skills. Studies in the psychology of religion suggested that a more complex religious measure based on religious orientation was necessary to understand these correlations. Additionally, schema theory offered a cognitive framework within which to experimentally test the cause of these correlations. This study found that primed religious schema did not account for …

Automated Data Type Identification And Localization Using Statistical Analysis Data Identification, Sarah Jean Moody

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research presents a new and unique technique called SÁDI, statistical analysis data identification, for identifying the type of data on a digital device and its storage format based on data type, specifically the values of the bytes representing the data being examined. This research incorporates the automation required for specialized data identification tools to be useful and applicable in real-world applications. The SÁDI technique utilizes the byte values of the data stored on a digital storage device in such a way that the accuracy of the technique does not rely solely on the potentially misleading metadata information but rather …

Movement Patterns And Multi-Scale Factors That Influence Exotic Brook Trout And Endemic Bonneville Cutthroat Trout Distribution And Abundance In The Mill Creek Drainage, Utah, Benjamin Keith Nadolski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Introduced brook trout (Salvelinus fontinalis) are implicated as a primary factor leading to the decline in distribution and abundance of native cutthroat trout (Oncorhynchus clarkii). However, not all introductions are successful, suggesting local conditions influence the success of invasions. Therefore, I sought to determine the multi-scale factor(s) that influence brook trouts’ invasion success of native Bonneville cutthroat trout (Oncorhynchus clarkii utah) habitats in Mill Creek, Utah. I conducted patch occupancy surveys to determine watershed-scale brook trout and cutthroat trout distribution. I also determined the relative abundance of brook trout and cutthroat trout at the …

Modeling The Electrodynamics Of The Low-Latitude Ionosphere, Christian Stephen Wohlwend

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The electrodynamics of the Earth's low-latitude ionosphere is dependent on the ionospheric conductivity and the thermospheric neutral density, temperature, and winds present. This two-part study focused on the gravity wave seeding mechanism of equatorial plasma depletions in the ionosphere and the associated equatorial spread F, as well as the differences between a two-dimensional flux tube integrated electrodynamics model and a three-dimensional model for the same time period. The gravity wave seeding study was based on a parameterization of a gravity wave perturbation using a background empirical thermosphere and a physics-based ionosphere for the case of 12 UT on 26 September …

An Investigation Of The Effects Of Differential Reinforcement Of Alternative Behavior On Students With Mild/Moderate Disabilities In A School Classroom, Katrina Spangenberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated the effects of differential reinforcement of alternative behavior (DRA), a behavior reduction procedure, on problem behavior exhibited by three elementary school students in a general education classroom. DRA involves reinforcement of an alternative behavior while withholding reinforcement for the inappropriate behavior. The three participants were classified as experiencing mild/moderate disabilities but received most services (and participated in this research) in a general education classroom. Problem behaviors included off-task, talk-outs, and inappropriate touching. Alternative behaviors included on-task and hand-raising to get teacher attention. Results indicated that DRA decreased off-task and talk-out behavior for two participants, although effects were …

Modeling, Designing, Fabricating, And Testing Of Channel Panel Flat Plate Heat Pipes, James R. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flat plate heat pipes are very efficient passive two-phase heat transport devices. Their high efficiency and low mass are desirable in the aerospace and electronics industries. The highly competitive nature of the thermal management industry results in little awareness of the capabilities of at plate heat pipes, which has resulted in only a few applications of the technology. In the year 2000 a research and development project sponsored by Space Dynamics Laboratory was launched to investigate building carbon-based at heat pipes. The flat configuration is desireable to incorporate many components onto one thermal management system. Development led to the adoption …

Technologically Assisted Intervention (Tai): Are Clients Satisfied With Online Therapy?, Jennifer A. Morrow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the level of satisfaction reported by participants of a technologically assisted intervention study (TAI). TAI is a type of teletherapy done through online, live video conferencing. Satisfaction was examined at three different time points, post therapy, 3-months post therapy, and 6-months post therapy. Analyses examined if there were any changes in reported satisfaction over the three time periods. Participants received cognitive behavioral therapy (CBT) targeted at reducing symptoms of mild to moderately severe depression. A satisfaction measure was developed for this study, and included quantitative and qualitative items which were analyzed to determine participants' level of satisfaction. …

Principals' Perspectives On Adolescent Literacy Implementation And Support In Secondary Schools: Views Through A Sociocultural Lens, Jack A. Robinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this study, interview data were analyzed to illustrate the perspectives of five secondary school principals in adolescent literacy implementation and support. These principals fell on the continuum from beginning practitioners in adolescent literacy to “seasoned veterans.” They were selected based on the recommendations of their district’s assistant superintendents and/or curriculum directors. I interviewed two high school principals, two middle school principals, and one junior high school principal.

Much emphasis has been placed over the last several decades on improving the reading skills of elementary school children, especially in the primary grades. While this goal continues to be an important …

Academic Performance As A Predictor Of Student Growth In Achievement And Mental Motivation During An Engineering Design Challenge In Engineering And Technology Education, Nathan Mentzer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this correlational research study was to determine if students’ academic success was correlated with: (a) the student change in achievement during an engineering design challenge; and (b) student change in mental motivation toward solving problems and critical thinking during an engineering design challenge. Multiple experimental studies have shown engineering design challenges increase student achievement and attitude toward learning, but conflicting evidence surrounded the impact on higher and lower academically achieving students.

A high school classroom was chosen in which elements of engineering design were purposefully taught. Eleventh-grade student participants represented a diverse set of academic backgrounds (measured …

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …

Analysis Of Chemical Bonding In Clusters By Means Of The Adaptive Natural Density Partitioning, Dmitry Yu Zubarev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Models of chemical bonding are essential for contemporary chemistry. Even the explosive development of the computational resources including, both hardware and software, cannot eliminate necessity of compact, intuitive, and efficient methods of representing chemically relevant information. The Lewis model of chemical bonding, which was proposed eleven years before the formulation of quantum theory and preserves its pivotal role in chemical education and research for more than ninety years, is a vivid example of such a tool. As chemistry shifts to the nanoscale, it is becoming obvious that a certain shift of the paradigms of chemical bonding is inescapable. For example, …

Hydrogen Production Using Geothermal Energy, Theodore Wayne Hand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With an ever-increasing need to find alternative fuels to curb the use of oil in the world, many sources have been identified as alternative fuels. One of these sources is hydrogen. Hydrogen can be produced through an electro-chemical process. The objective of this report is to model an electrochemical process and determine gains and or losses in efficiency of the process by increasing or decreasing the temperature of the feed water. In order to make the process environmentally conscience, electricity from a geothermal plant will be used to power the electrolyzer. Using the renewable energy makes the process of producing …