Digital Commons Network^™

In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.

A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations …

Mathematical Modeling Of Light Utilization And The Effects Of Temperature Cycles On Productivity In A Steady-State Algal Photobioreactor, Peter Edwin Zemke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work presented here investigated two methods of improving productivity in microalgal photobioreactors: applying temperature cycles intended to maximize photosynthesis and minimize respiration, and development of a mathematical model that predicts improvements in photon utilization using temporal light dilution (flashing).

The experiments conducted on diurnal temperature cycles with Dunaliella tertiolecta in 30-L outdoor photobioreactors showed that a properly chosen temperature cycle can improve mass and energy productivity by 18% over an identical photobioreactor with a constant temperature. However, excessively large temperature cycle amplitudes reduced productivity. A 4-7% increase in energy content was observed in microalgae exposed to temperature cycles. The …

Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation, Shantanu Wahal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrients present in digested animal waste can be utilized for algae cultivation under suitable conditions. Algal growth, however, depends on the chemical forms and speciation of these nutrients. In this study a chemical equilibrium model was first used to describe nutrient speciation and predict conditions that enhance the solubility of nutrients in anaerobic digester effluent. Dilution with water and separation of large particulates greatly improved nutrient availability and light penetration - conditions favorable for algal cultivation. Algae growth was tested using three strains - Scenedesmus dimorphous (UTEX # 417), Chlorella vulgaris (UTEX# 265), and an algal isolate (designated as LLAI …

Generation And Analysis Of Verbal Route Directions For Blind Navigation, John Nicholson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

According to the National Federation of the Blind, there are an estimated 10 million people in the United States who are visually impaired. Of these, 1.3 million are legally blind. Many people with extreme vision loss receive orientation and mobility training in order to help them learn skills that allow them to travel and navigate multiple types of indoor and outdoor environments. Even with this training, a fundamental problem these people face is learning new routes, especially in environments with which they are not familiar. Although the research community has developed a number of localization and navigation aids that are …

Optimal Sensing And Actuation Policies For Networked Mobile Agents In A Class Of Cyber-Physical Systems, Christophe Tricaud

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main purpose of this dissertation is to define and solve problems on optimal sensing and actuating policies in Cyber-Physical Systems (CPSs). Cyber-physical system is a term that was introduced recently to define the increasing complexity of the interactions between computational hardwares and their physical environments. The problem of designing the "cyber'' part may not be trivial but can be solved from scratch. However, the "physical'' part, usually a natural physical process, is inherently given and has to be identified in order to propose an appropriate "cyber'' part to be adopted. Therefore, one of the first steps in designing a …

A Study On Stainless Steel 316l Annealed Ultrasonic Consolidation And Linear Welding Density Estimation, Raelvim Gonzalez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ultrasonic Consolidation of stainless steel structures is being investigated for potential applications. This study investigates the suitability of Stainless Steel 316L annealed (SS316L annealed) as a building material for Ultrasonic Consolidation (UC), including research on Linear Welding Density (LWD) estimation on micrographs of samples. Experiment results are presented that include the effect of UC process parameters on SS316L annealed UC, optimum levels of these parameters, and bond quality of ultrasonically consolidated SS316L annealed structures in terms of LWD. In support to these efforts, a Measurement System Analysis for LWD assessment has been performed, and a new instrument for LWD measurement …

A Synthetic Biological Engineering Approach To Secretion- Based Recovery Of Polyhydroxyalkanoates And Other Cellular Products, Elisabeth Linton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The costs associated with cellular product recovery commonly account for as much as 80% of the total production expense. As a specific example, significant recovery costs limit commercial use of polyhydroxyalkanoates (PHA), which comprise a class of microbially-accumulated polyesters. PHAs are biodegradable compounds that are of interest as a sustainable alternative to petrochemically-derived plastics. Secretion-based recovery of PHAs was studied to decrease PHA production costs. Type I and II secretory pathways are commonly used for the translocation of recombinant proteins out of the cytoplasm of E. coli. Proteins were targeted for translocation using four signal peptides (HlyA, TorA, GeneIII, …

Pulsed-Laser Excited Photothermal Study Of Glasses And Nanoliter Cylindrical Sample Cell Based On Thermal Lens Spectroscopy, Prakash Raj Joshi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research in this dissertation presents Pulsed-Laser Excited photothermal studies of optical glasses and cylindrical sample cell.

First, a study of a photothermal lens experiment and the finite element analysis modeling for commercial colored glass filters is done. The ideal situation of a semiinfinite cylinder approximate model used to describe the photothermal lens experiment requires the boundary condition that there is no transfer of heat from the glass to surrounding when the glass is excited with a laser. The finite element analysis modeling for photothermal signal with coupling heat with surrounding shows the thermal heat transfer between the glass surface …

The Effect Of Explicit Timing On Math Performance Using Interspersal Assignments With Students With Mild/Moderate Disabilities, Fangjuan Hou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Explicit timing and interspersal assignments have been validated as effective methods to facilitate students' math practice. However, no researchers have explored the combinative effect of these two methods. In Study 1, we extended the literature by comparing the effect of explicit timing with interspersal assignments, and interspersal assignments without timing. Generally, participants' rate of digits correct on easy and hard addition problems was higher during the explicit timing condition than during the untimed condition. However, the participants' rate of digits correct decreased after initial implementation of the explicit timing condition.

Motivation plays a crucial role in maintaining performance levels and …

Minimum Symbol Error Rate Timing Recovery System, Nagendra Bage Jayaraj

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a timing error detector (TED) used in the symbol timing synchronization subsystem for digital communications. The new timing error detector is designed to minimize the probability of symbol decision error, and it is called minimum symbol error rate TED (MSERTED). The new TED resembles the TED derived using the maximum likelihood (ML) criterion but gives rise to faster convergence relative to MLTED. The new TED requires shorter training sequences for symbol timing recovery. The TED operates on the outputs of the matched filter and estimates the timing offset. The S-curve is used as a tool for analyzing …

A Finite Domain Constraint Approach For Placement And Routing Of Coarse-Grained Reconfigurable Architectures, Rohit Saraswat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Scheduling, placement, and routing are important steps in Very Large Scale Integration (VLSI) design. Researchers have developed numerous techniques to solve placement and routing problems. As the complexity of Application Specific Integrated Circuits (ASICs) increased over the past decades, so did the demand for improved place and route techniques. The primary objective of these place and route approaches has typically been wirelength minimization due to its impact on signal delay and design performance. With the advent of Field Programmable Gate Arrays (FPGAs), the same place and route techniques were applied to FPGA-based design. However, traditional place and route techniques may …

Experiment And Simulation On The Dynamics Of A Slug Of Liquid Oxygen Displaced By A Pulsed Magnetic Field, Jeffrey C. Boulware

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A magnetic fluid system could potentially replace mechanically moving parts in a satellite as a means of increasing system reliability and mission lifetime, but rather than a standard ferrofluid with magnetic particles, liquid oxygen (LOX) may be a more adequate working fluid. As a pure paramagnetic cryogen, LOX is already heavily used in space, but still requires basic research before being integrated into system development. The objectives of the research conducted were to verify LOX as a magnetic working fluid through experiment and establish a theoretical model to describe its behavior. This dissertation presents the theoretical, experimental, and numerical results …

Examination Of Deformation In Crystalline Rock From Strike-Slip Faults In Two Locations, Southern California, David H. Forand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Damage zones adjacent to or associated with faults are important to the geologic community because of their implications to hazards and their ability to preserve evidence for, and show history of, slip, fluid flow, and deformation associated with large strike-slip faults. We examine two fault zones in southern California where fault zone damage is expressed. We revisit the drilled crystalline core from the Cajon Pass California drill hole, 4 km northeast of the San Andreas fault (SAF), and 1 km north of the Cleghorn fault, to perform a systematic structural analysis of deformation and alteration associated with strike-slip faulting at …

Classical Foundations For A Quantum Theory Of Time In A Two-Dimensional Spacetime, Nathan Thomas Carruth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We consider the set of all spacelike embeddings of the circle S1 into a spacetime R1 × S1 with a metric globally conformal to the Minkowski metric. We identify this set and the group of conformal isometries of this spacetime as quotients of semidirect products involving diffeomorphism groups and give a transitive action of the conformal group on the set of spacelike embeddings. We provide results showing that the group of conformal isometries is a topological group and that its action on the set of spacelike embeddings is continuous. Finally, we point out some directions for future research.

Library Synthesis Of Anticancer And Antibacterial Agents Via Azide Chemistry, Jianjun Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Various anticancer and antibacterial agents have been synthesized via azide chemistry by taking advantage of carbohydrate. Starting from the synthesis of 14 glycosyl azides, a library of carbohydrate-oxazolidinone conjugates and a library of carbohydrate-cyclopamine conjugates with biological interests were synthesized based on a highly efficient "click reaction" assisted by sonication. Some of the conjugates have improved solubility and enhanced anticancer activity.

A library of neomycin B derivatives with various modifications at the 5" position has been synthesized. Two leads exhibit prominent activity against both methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Antibacterial activities were measured when combined with other …

Three Essays On Environmental- And Spatial-Based Valuation Of Urban Land And Housing, Lu Liu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation attempts to provide a comprehensive examination on the non-market valuation of the effect of open space amenities and local public infrastructure on the value of urban land and housing with both spatial heterogeneity and project heterogeneity. The demand for raw land is a derived demand for housing built on it. Therefore, we need to examine the land market and the housing market together. On the one hand, we estimate the value of urban land in a market that does not satisfy the usual assumptions of a competitive market structure as well as incentive incompatibility issues for transaction participants, …

Dancing With Heretics: Essays On Orthodoxy, Questioning And Faith, Darren M. Edwards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

While much has been written about the conflicts, supposed or actual, between logic and faith, science and religion, few accounts of the personal turmoil these conflicts can cause exist. Likewise, many of these nonfiction accounts are written from a distinctly polarized place leaning either to science or faith.

In this thesis, I mix research and history with memoir and a sense of poetry to explore my personal experience with this conflict. At its outset, I hoped for this project to capture my struggle as an orthodox member of The Church of Jesus Christ of Latter-day Saints (LDS) in dealing with …

Planning For Closure Of The Logan City/Cache County Landfill And Surrounding Landscape, Kristofor Lee Kvarfordt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Planning for closure requires in depth analysis into many operational, environmental, and social factors. Ideally, the planning process should resolve as many of the technical, social, and aesthetic requirements as possible by systematically addressing the various elements that influence the final design. This research identified the significant issues related to planning for the end use of the current Logan landfill after it reaches capacity in 18-20 years and the associated lagoons and wetlands. The current closure plan calls for simply recontouring the landfill to stabilize the slopes, then revegetating. The location of the site has serious implications for environmental impact …

A Spatiotemporal Analysis Of Aspen Decline In Southern Utah’S Cedar Mountain, Using Remote Sensing And Geographic Information Systems, David M. Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Widespread mortality of quaking aspen (Populus tremuloides Michx.) has occurred over large expanses of the Western US during the 20^th century. While much of this decline was due to conifer encroachment into seral aspen, significant aspen losses also occurred in areas of persistent aspen and may have been exasperated by drought conditions. Aspen decline has been especially notable at Cedar Mountain, Utah, an area of mostly private land and extensive persistent aspen coverage. The objectives of this study were to create a time series of live and dead aspen cover on the Cedar Mountain landscape, using remotely sensed …

Investigating Small-Scale Dynamical Features In The Mesopause Region, Deepak B. Simkhada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utilizing analyses of observational data, we performed a detailed study to investigate short-period atmospheric gravity waves and ripples, and instabilities in the mesopause region. Recent coordinated measurements from Haleakala Observatory, Maui, HI via airglow wave imaging, meteor wind radar, and Na wind temperature lidar have provided a unique dataset for this study. Gravity waves generated in the lower atmosphere propagate energy upwards into the mesosphere and lower thermosphere region where they modulate the airglow emissions, and later break and deposit their momentum, causing significant perturbations in winds and temperatures. Ripples, on the other hand, are likely generated by localized shear …

Random Forests Applied As A Soil Spatial Predictive Model In Arid Utah, Alexander Knell Stum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Initial soil surveys are incomplete for large tracts of public land in the western USA. Digital soil mapping offers a quantitative approach as an alternative to traditional soil mapping. I sought to predict soil classes across an arid to semiarid watershed of western Utah by applying random forests (RF) and using environmental covariates derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and digital elevation models (DEM). Random forests are similar to classification and regression trees (CART). However, RF is doubly random. Many (e.g., 500) weak trees are grown (trained) independently because each tree is trained with a new randomly …

Thermo-Mechanical Reliability Of Micro-Interconnects In Three-Dimensional Integrated Circuits: Modeling And Simulation, Omar Rodriguez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three-dimensional integrated circuits (3D ICs) have been designed with the purpose of achieving higher communication speed by reducing the interconnect length between integrated circuits, and integrating heterogeneous functions into one single package, among other advantages. As a growing, new technology, researchers are still studying the different parameters that impact the overall lifetime of such packages in order to ensure the customer receives reliable end products. This study focused on the effect of four design parameters on the lifetime of the interconnects and, in particular, solder balls and through-silicon vias (TSVs). These parameters included TSV pitch, TSV diameter, underfill stiffness and …

Correlation Of Age-Specific Phenylalanine Levels On Intellectual Outcome In Patients With Phenylketonuria, Krista S. Viau

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study includes data collected from a retrospective chart review of patients with phenylketonuria treated at the University of Utah Metabolic Clinic. Among the
approximately 175 patients treated for phenylketonuria at this clinic, 55 patients (28 female) met the inclusion criteria for the present study. Based on the diagnostic Phe
level, 66.7% were classified as having classic phenylketonuria, 18.5% with moderate phenylketonuria, and 14.8% with mild phenylketonuria.

Subjects’ cognitive status was measured with one of three neuropsychological tests: Wechsler Intelligence Scale for Children third and fourth editions and the Wechsler Adult Intelligence Scale third edition. Due to structural differences among …

Dynamics Of Van Der Waals Clusters: Theoretical And Computational Studies, Jordan Aleksander Ramilowski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The marriage of two very powerful techniques – cryogenic matrix isolation spectroscopy and seeded supersonic molecular beams – has led to the development of a novel type of cryogenic matrix isolation spectroscopy in ultracold, near 0 K, He droplets. The technique known as helium nanodroplet isolation (HENDI) has seen tremendeous experimental interest over the past 20 years; this in turn has resulted in the availability of spectroscopic data for many molecules and clusters embedded in He clusters. The experimental findings have motivated a large number of theoretical calculations. This dissertation focuses on theoretical and computational studies of the rotational dynamics …

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes …

Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil …

Thaw: A Memoir, Diane Bush

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This collection of creative nonfiction essays is a hybrid text of visual and verbal narratives located broadly within the genres of memoir, research-based nonfiction, and history. Women's memoirs, including a number of non-traditional texts, historical narratives, and an archival collection of photographs, provided springboards for the exploration of and reflection on the emotional terrain of loss, the ache of remembrance, and the ultimate desire for peace.

Ultimately, this work is a search for solace amidst emotional upheaval, beginning in childhood, after the deaths of my father, mother, first husband, and beloved aunt. Unable to sit still with my grief, I …

Reconciling Holocene Alluvial Records In Buckskin Wash, Southern Utah, Jonathan E. Harvey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most approaches to interpreting alluvial records in drylands fall into one of two categories: (1) The "arroyo problem," wherein workers study cycles of streambed aggradation and degradation in broad, unconstricted alluvial valleys; and (2) paleoflood hydrology, where alluvial sequences in constricted bedrock canyons are interpreted as paleoflood deposits from streams with stable channel grade and geometry. Both approaches can be valid in their end-member settings, but there is confusion about how the two record types relate in a single drainage. We address this disconnect in Buckskin Wash, an ephemeral stream that consists of a broad alluvial reach draining into a …

An Experimental Comparison Of Middle School Students' Motivation And Preference Toward Text- And Graphic-Based Programming, Stephen E. Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to compare seventh-grade students' motivation and preference toward text-based programming using Visual Basic, and graphics-based programming using Robolab. Motivation was defined by the My Class Activities questionnaire using the dimensions of interest, challenge, choice, and enjoyment. Preference was determined through team and individual student choice. This study was conducted with 122 students from three 6-week technology education classes. This study examined two hypotheses. First, middles school students will be more motivated when using a graphics-based programming language than text-based as measured by the My Class Activities survey. The second hypothesis for this study …

Teachers' Perceptions Of The Effects Of The Arizona Instrument To Measure Standards (Aims) Test On Arizona High School Math And English Curriculum And Instruction, Joseph Leland Heywood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This is a doctoral dissertation centered on a qualitative research case study on teachers' perceptions of the effects of a particular high-stakes test—the Arizona Instrument to Measure Standards (AIMS) on high school English and math curriculum and instruction. Specifically, this case study involved three focus group interviews at three Arizona high schools. Participants were experienced English and math teachers at each school site. To broaden the perspective gained from the focus group interviews, the study included classroom observations and document analysis. Two of the high schools chosen are located on the Navajo Reservation and were specifically chosen to include an …