Digital Commons Network^™

Computational Tools For Modeling And Simulation Of Sooting Turbulent Non-Premixed Flames, Victoria B. Stephens

Theses and Dissertations

Turbulent combustion systems are physically complex processes that involve many interdependent phenomena---including turbulent fluid dynamics, multi-component mass transfer, convective and radiative heat transfer, and multiphase flow---that occur over a wide range of length and time scales. Modeling and simulation studies complement experimental work by implementing and validating models and providing predictive capabilities, but current software tools are often limited by a lack of standardization and best practices, non-robust implementation, or over-specialization. Some topics in combustion CFD research, notably radiative heat transfer and soot modeling, are critically underrepresented in simulation studies as a result of software limitations. This project establishes and …

Computational Studies Of Dinuclear Catalytic Reaction Mechanisms, James Curtis Coombs Iii

Theses and Dissertations

Heterodinuclear and homodinuclear metal complexes with a direct metal-metal interaction offer the potential for unique catalysis due to cooperativity effects that impact reaction mechanisms, reactivity, and selectivity. Quantum-chemical density functional theory (DFT) calculations can directly examine the origin of dinuclear reactivity and selectivity effects. Chapter 1 provides a short overview of heterodinuclear and homodinuclear catalysts that have been experimentally and computationally examined. Chapter 2 reports our study using DFT methods to understand the mechanism and reactivity of a heterodinuclear Co-Zr catalyst with phosphinoamide ligands that catalyzes a Kumada coupling between alkyl halides and alkyl Grignards. Chapter 3 reports DFT calculations …

A Comparison Of Methods Of Rating Creative Writing: A Many-Facets Rasch And User Experience Analysis, Alicia Mcintire

Theses and Dissertations

The use of analytic rubrics remains popular in the field of writing assessment. Previous work in second-language writing assessment and other fields like economics suggest that ratings produced using this method may have lower reliability on average than other methods. Currently, there is little research on the reliability of ratings of creative writing, specifically creative writing authored by adults. This study evaluated the reliability of ratings from an analytic rubric against those produced by a comparative method called Randomly Distributed Comparative Judgment and the rater experience of the methods. The author administered a science fiction and fantasy contest in which …

Developing An Accurate Simulation Model For Predicting Friction Stir Welding Processes In 2219 Aluminum Alloy, Kennen Brooks

Theses and Dissertations

Modeling of friction stir welding (FSW) is challenging, as there are large gradients in both strain rate and temperature that must be accounted for in the constitutive law of the material being joined. Constitutive laws are most often calibrated using flow stresses from hot compression or hot torsion testing, where strain rates are much lower than those of the FSW process. As such, the current work employed a recently developed method to measure flow stresses in AA 2219-T67 at the high strain rates typical of FSW. These data were used in the development of a finite element simulation of FSW …

The Effect Of Gut Microbiota On Overwintering Success In Mule Deer, Emma Wilcox

Theses and Dissertations

Mule deer are an important rangeland grazer, large prey species, and game animal for the state of Utah, so herd size is monitored and managed actively. A significant cause of population decline is poor overwintering survival, including from the lack of available forage during winter months. Mule deer energy storage is correlated with greater overwintering success, so physical estimates of energy storage including body condition score (BCS), rump fat (RF), and loin thickness (LT), can be used to track and predict a herd's health. Current methods of collecting deer information are costly, time consuming, and cause physical stress to deer, …

Wildfire Modeling With Data Assimilation, Andrew Johnston

Theses and Dissertations

Wildfire modeling is a complex, computationally costly endeavor, but with droughts worsening and fires burning across the western United States, obtaining accurate wildfire predictions is more important than ever. In this paper, we present a novel approach to wildfire modeling using data assimiliation. We model wildfire spread with a modification of the partial differential equation model described by Mandel et al. in their 2008 paper. Specifically, we replace some constant parameter values with geospatial functions of fuel type. We combine deep learning and remote sensing to obtain real-time data for the model and employ the Nelder-Mead method to recover optimal …

Advanced Isogeometric Discretization Techniques, Kyle Dennis Richardson

Theses and Dissertations

In this dissertation, I provide a robust, efficient inverse mapping algorithm for use in immersed simulation methods, specifically in the Flex Representation Method. I also explore a structural theory that unifies the theories of solids, shells, beams, and rigid bodies. As part of this, I preform a preliminary exploration of applying the Flex Representation Method to shells. Finally, I explore why higher order elements suffer from small critical time steps in explicit dynamics. I then propose a simple method of remedying this issue by exploiting the properties of U-splines.

Incorporating Diversity, Equity, And Inclusion Principles Into Our Metadata, Nicole Lewis, Allie Mccormack, Rachel Jane Wittmann

Faculty Publications

This presentation was given as part of the Best of Core Forum Webinar Series.

In early 2021, a group of librarians at two university libraries embarked on a journey to review and update harmful subject headings and other metadata in their catalog, digital library, and finding aids. This session will discuss the background of the project and where the librarians currently stand in the process of remediating these records, including their efforts to create student internships to address problematic language in archival finding aids as well as create a community user advisory group. Special attention will be given to creating …

Determining Figure Skating Jump Under-Rotation In Real-Time Using Imu Sensors During Practice, Duncan O. Furgeson

Theses and Dissertations

We explore the use of machine learning to detect under-rotation in figure skating jumps. Under- rotation in jumps is difficult for the skater to sense but learning to recognize under-rotation is an impor- tant part of learning proper jump technique. To address this difficulty, we present the Under-rotation Monitor, or UR Monitor, a system for detecting under-rotated figure skating jumps in real-time. UR Monitor uses a single inertial measurement unit (IMU) attached to the skater's waist that sends a stream of accelerometer and gyroscope data to a mobile phone via Bluetooth. The mobile phone creates and sends an input vector …

The Cholera-Fiend: Cheap Fiction, Medical Professionals, And Entertainment, Sariah Fales Harrington

Theses and Dissertations

First published in 1849, Charles Averill’s The Cholera-Fiend follows three villains as they attempt to artificially propagate cholera for their own villainous purposes in New York City. Gumbo, a Black servant to one of the villains, is meant to be the humorous relief in the text, but Gumbo experiences a calculated dehumanization from human to disabled, which causes him to be more at-risk for a health crisis—such as a tapeworm or cholera—than his white counterparts. Through analyzing the genre of cheap fiction, the views of medical professionals towards Black bodies, and other ways Black bodies were used as entertainment, I …

Retention Forces For Drops On Microstructured Superhydrophobic Surfaces, Shaur Humayun, R. Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

Accurate models of retention forces between drops and superhydrophobic (SH) surfaces are required to predict drop dynamics on the surface. This retention force is, in turn, useful in modeling heat transfer rates for dropwise condensation on a SH surface. Drop contact angle distribution and base area on SH surfaces are essential factors for predicting retention forces. The present work measures the contact angle distribution and base area shapes of various drop sizes over a wide range of solid fraction for inclined microstructured SH surfaces at the point of drop departure. Base area shape was found to be well approximated using …

Temporal Fluency In L2 Self-Assessments: A Cross-Linguistic Study Of Spanish, Portuguese, And French, Mandy Case

Theses and Dissertations

The present study explores the relationship between temporal fluency and second language (L2) learners' self-assessed and externally assessed proficiency level across the target languages French, Spanish, and Portuguese. Temporal fluency is operationalized as articulation rate (the speed of speech), the mean length of utterance, and the silent pause frequency. Participants (n = 283) in this study are native English speakers enrolled in upper-division language courses at Brigham Young University (BYU). Each participant completed both a self-assessment (the Language Ability Self-Evaluation Resource or LASER) as well as the Computerized Oral Proficiency Interview (OPIc) to receive an external proficiency assessment. Temporal fluency …

Parametric Structural Optimization Of A Wheel Using The Flex Representation Method, Gregory John Vernon

Theses and Dissertations

The use of the finite element method within an optimization workflow is fraught with challenges that limit the automation of such workflows. These challenges are inherent to the traditional finite element formulations which are heavily dependent on a manual meshing process that introduces variability that is challenging to account for within an automated workflow. The recently developed flex representation method (FRM) provides a salient solution to the manual meshing process without sacrificing solution accuracy. In response to the development of FRM a global automotive company requested a study to explore the applicability of FRM to one of their sizing-optimization problems: …

Medical And Socioeconomic Predictors Of Psychosocial Functioning In Pediatric Hydrocephalus, Vanessa Wall

Theses and Dissertations

Hydrocephalus can impact all areas of health, including physical, cognitive, and psychosocial functioning. Etiology can be a major factor in health outcomes, but prior research on psychosocial functioning in hydrocephalus has been with limited etiologies. This study examined psychosocial functioning using the Behavioral Assessment System for Children, Third Edition (BASC-3) and the Hydrocephalus Outcome Questionnaire (HOQ) in children aged 5-17 years old. BASC-3 and HOQ parent report scores were compared between hydrocephalus etiologies. Medical factors (number of CSF diversion procedures, history of seizures, and years with hydrocephalus) and SES factors (family income, parent education, and parent occupational status) were examined …

The Role Of Chitinase A In Mastitis-Associated Escherichia Coli Pathogenesis, Weston D. Hutchison

Theses and Dissertations

Bovine mastitis is a common disease among dairy cattle characterized by the inflammation of the udders and loss of milk production. Mastitis-associated Escherichia coli (MAEC) are frequent causes of the disease, but the features that distinguish them from other E. coli strains remain enigmatic. MAEC infections can range from sub-clinical to severe, acute cases that can be fatal. Historically, the severity of mastitis has been attributed to host factors but more recently, a few bacterial genes have been shown to contribute to virulence in mastitis infections. In a large-scale genomic analysis of >100 MAEC isolates the gene for Chitinase A …

The Flex Representation Method: Versatile Modeling For Isogeometric Analysis, Christopher David Whetten

Theses and Dissertations

The Flex Representation Method (FRM) leverages unique computational advantages of splines to address limitations in the process of building CAE simulation models from CAD geometric models. Central to the approach is the envelope CAD domain that encapsulates a CAD model. An envelope CAD domain can be of arbitrary topological and geometric complexity. Envelope domains are constructed from spline representations, like U-splines, that are analysis-suitable. The envelope CAD domain can be used to approximate none, some, or all of the features in a CAD model. This yields additional simulation modeling options that simplify the model-building process while leveraging the properties of …

Autonomic Responses During Animated Avatar Video Modeling Instruction Of Social Emotional Learning To Students With Adhd: A Mixed Methods Study, Jesse D. Rhodes

Theses and Dissertations

For those with attention deficit hyperactivity disorder (ADHD), social interactions involving high levels of face-to-face interaction can raise stress levels and emotional dysregulation. Using animated avatar video models may mitigate potential emotional dysregulation while learning social skills in these populations. This study examined autonomic data of adolescents aged 7-13 diagnosed with attention deficit hyperactivity disorder (ADHD), n=5 during avatar animated video modeling (AAVM) of social and emotional skills. This was a replication study with the addition of biofeedback data collection and a change of population. Participants were given three Nearpod training modules with AAVM and multiple-choice quizzes on self-awareness, social …

Developing A Quantitative Understanding Of U-Substitution In First-Semester Calculus, Leilani Camille Heaton Fonbuena

Theses and Dissertations

In much of calculus teaching there is an overemphasis on procedures and manipulation of symbols and insufficient emphasis on conceptual understanding of calculus topics. As such students to struggle to understand and use calculus ideas in applied settings. Research shows that learning calculus topics from a quantitative reasoning-perspective results in more powerful and flexible conceptions of calculus topics like integration. However, topics beyond introducing integrals and the Fundamental Theorem of Calculus, like u-substitution, have yet to be explored from a quantity-based perspective. In this study, I conducted a set of two clinical interviews where we discussed quantitative meanings of integrals, …

Teacher Perceptions Of Grades And Grading In A Pandemic, Michael V. Anderson

Theses and Dissertations

A grade serves as the primary means of reporting feedback to teachers, students, and parents about the student's level of learning (Heflebower et al., 2014). Many schools have attempted to have teachers adopt standards-based grading, yet school leaders do not know teachers' perceptions about grades and grading. This quantitative study examines the perceptions of 1271 secondary teachers in one school district regarding grades and grading and how they may have changed as a result of the COVID-19 pandemic. Data collected from a survey reveals how changes in teacher perceptions about grades and grading may yield an opportunity for further standards-based …

A Machine Learning Approach For Identification Of Low-Head Dams, Salvador Augusto Vinay Mollinedo

Theses and Dissertations

Identifying Low-head dams (LHD) and creating an inventory become a priority as fatalities continue to occur at these structures. Because obstruction inventories do not specifically identify LHDs, and they are not assigned a hazard classification, there is not an official inventory of LHD. However, there is a multi-agency taskforce that is creating an inventory of LHD. All efforts have been performed by manually identifying LHD on Google Earth Pro (GE Pro). The purpose of this paper is to assess whether a machine learning approach can accelerate the national inventory. We used a machine learning approach to implement a high-resolution remote …

Parental Warmth And Disciplinary Strategies In Two-Parent-Adoptive And Biological Families, Jordan Coburn

Theses and Dissertations

Adopted children enter families with parents who on average are older, have higher income, and have more education than other family structures. Because adopted children are moving into families with more resources, research suggests that they would do just as well as, and perhaps even better than, children in biological two-parent households. However, this is not always the case. Understanding how different variables could offset any negative results of adoption is a puzzle that researchers are continually exploring. Previous research has investigated differences in investments from adoptive and biological parents through multiple theoretical lenses. I seek to add to current …

Structural Reasoning With Rational Expressions, Dana Steinhorst

Theses and Dissertations

Many students struggle to make sense of algebraic expressions in math. This lack of understanding results in students making symbolic manipulation errors, hindering their procedural fluency. Researchers believe these errors are linked to students' lack of structural reasoning. While research has shown that students rarely engage in expert structural reasoning, little is known about how students actually reason structurally. In this study, I interviewed six high school calculus students to study the way they identified, matched, and evaluated structures as they solved problems involving rational expressions and equations. I analyzed the participant interviews and outlined the matching process they used …

Teaching Social-Emotional Learning To Children With Autism Using Animated Avatar Video Modeling, Emelie Davis

Theses and Dissertations

People with a diagnosis of autism spectrum disorder (ASD) often have difficulties understanding or applying skills related to Social-Emotional Learning (SEL). An individual having a better understanding of SEL concepts is generally associated with more fulfilling connections with others and increased satisfaction in life. Since people with ASD tend to have greater success with learning in structured environments, we created a module to teach these skills using Nearpod. These modules were created with videos of a person embodying a cartoon dog face using Animoji for two reasons; because the animation was meant to appeal to children, and the creation was …

Determination Of A Catalytic Mechanism By Time Resolved Fourier Transform Infrared Spectroscopy And Time Domain Analysis Of Data From Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Jacob T. Davis

Theses and Dissertations

Heterobimetallic catalysts offer large potential for efficient and selective catalysis of a wide range of reactions. Better understanding of these catalytic mechanisms could yield further improvement in their catalytic abilities. Cp(CO)2Fe-Cu(IPr) (IPr = N,N-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) is a catalyst that has been reported to catalyze arene borylation. The catalytic mechanism of this catalyst that had been previously proposed had the initial step being a metal-metal cleavage. However, computational modeling suggested an alternate mechanism that could be more energetically favorable. Rather than a metal-metal cleavage as the initial step, we proposed a photoactivated carbonyl dissociation. To support this proposition, we performed time resolved …

Zeros Of A Family Of Complex-Valued Harmonic Rational Functions, Alexander Lee

Theses and Dissertations

The Fundamental Theorem of Algebra is a useful tool in determining the number of zeros of complex-valued polynomials and rational functions. It does not, however, apply to complex-valued harmonic polynomials and rational functions generally. In this thesis, we determine behaviors of the family of complex-valued harmonic functions $f_{c}(z) = z^{n} + \frac{c}{\overline{z}^{k}} - 1$ that defy intuition for analytic polynomials. We first determine the sum of the orders of zeros by using the harmonic analogue of Rouch\'e's Theorem. We then determine useful geometry of the critical curve and its image in order to count winding numbers by applying the harmonic …

Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging Of Defect-Bearing Ablator Materials In Extreme Conditions, Daniel S. Hodge

Theses and Dissertations

Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source …

Delivering Explicit Math Instruction Through Point-Of-View Video Modeling To Elementary Students With Autism Spectrum Disorder, Patsy Mccray Gibbs

Theses and Dissertations

There is significant literature demonstrating the effectiveness of video modeling for teaching skills to students with disabilities. Still, much less is known about how video modeling, particularly point-of-view video modeling (POV-VM), might be applied to teach academic skills to children with an autism spectrum disorder. This multiple probe single-case design study used explicit instruction techniques to teach multiplication, division, and fraction skills to two elementary-aged students with an autism spectrum disorder. A visual analysis of the data showed that POV-VM using explicit techniques to deliver the videos is an effective intervention for autistic students This research study adds to the …

Decision-Based Learning As A Tool For Teaching Statistics In A Peruvian University, Gloria Mora Barba

Theses and Dissertations

Many students find that learning statistics is difficult, especially novice learners first taking statistical classes. Instructors also struggle to teach statistics due to many challenges, such as students' misconceptions, lack of math skills, negative attitudes, and deficient instructional methods. A new pedagogical approach called Decision-Based Learning (DBL) has been developed to help instructors and students overcome these challenges. A group of Peruvian university professors in 2018 and 2019 were trained to use DBL. However, limited studies have explored DBL instructors' and students' experiences using DBL in Peru. The aim of this qualitative research study is to deeply understand the experiences …

Quantifying Shape Variation In An Antisymmetrical Trait In Xenophallus Umbratilis, Mary-Elise Johnson Nielsen

Theses and Dissertations

Antisymmetry is a striking, yet puzzling form of biological asymmetry. The livebearing fish Xenophallus umbratilis exhibits antisymmetry in the male intromittent organ and provides a system that is well-suited for studying the nature of variation in antisymmetrical traits. Using geometric morphometrics, I test the hypothesis that because the gonopodium is critical to fitness there will not be significant differences in gonopodium shape between the two gonopodial morphs in this species. My results are consistent with this prediction, though I found that gonopodium shape did differ with gonopodium size.

Is Teaching Experience A Predictor For School Psychologists' Confidence And Competence In Behavior Intervention Plans?, Misty Dawn Lainé Coplan

Theses and Dissertations

The Individuals with Disabilities Education Improvement Act (IDEIA) introduced Behavior Intervention Plans (BIPs) into United States law in 1990, and the reauthorization of IDEIA occurred in 2004. Even though BIPs have been codified into law, school personnel struggle to meet BIP mandates due to poor implementation fidelity. Barriers for BIP implementation are varied, but there is little research regarding whether practitioner competence and confidence through teaching experience is a factor. School psychologists (N = 122) from eight states completed a self-evaluation survey using the tailored design method. Results from the survey compared responses from school psychologists with and without teaching …