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Browsing Within An Academic Library, Holt Zaugg, Jillian Bunderson Jan 2025

Browsing Within An Academic Library, Holt Zaugg, Jillian Bunderson

Faculty Publications

Purpose – Browsing library resources is a method long used by researchers to expand their understanding of ill-defined projects and to have serendipitous research discoveries. This study sought to understand the browsing activities of students in an academic library. Design/methodology/approach – The study used two methods. First, a link to an online survey was posted on posters throughout the library inviting students to share their browsing experience. Second, library security officers (student employees) were asked to count the number of people browsing within the stacks as they conducted their hourly walk-throughs of the library. Browsing was broadly defined as anyone …

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What Can Artificial Intelligence Tell Us About The Literary Skills Needed To Dictate A Text Like The Book Of Mormon?, Brian C. Hales Jan 2025

What Can Artificial Intelligence Tell Us About The Literary Skills Needed To Dictate A Text Like The Book Of Mormon?, Brian C. Hales

Interpreter: A Journal of Latter-day Saint Faith and Scholarship

The first oral draft of the Book of Mormon dictated by Joseph Smith reflected remarkable literary refinement and complexity. Such observations demonstrate that he exhibited highly developed composition and oratory skills. To date, no scholar has attempted to describe the specific skills Joseph manifested while dictating. This essay addresses whether Artificial Intelligence (AI) could generate an accurate list of the skills necessary. It begins by identifying and informally testing eleven chatbots to see if they can accurately predict the skills needed to perform a task. Seeing success, they are next asked a long question about the skills needed to dictate …

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Encouraging Self-Regulation In An Online University Course For Preservice Teachers: An Intervention Study, Karen T. Arnesen, Charles R. Graham, Heather Leary, Alison I. Mcmurry Jan 2025

Encouraging Self-Regulation In An Online University Course For Preservice Teachers: An Intervention Study, Karen T. Arnesen, Charles R. Graham, Heather Leary, Alison I. Mcmurry

Faculty Publications

Although self-regulation (SR) has long been seen as an important educational concept, we know little about how to foster it in higher education online student populations. This research addresses this need by introducing an SR intervention into a preservice teacher course. The 30 students who participated used an intervention consisting of weekly student goal setting and self-reflection. Using data collected from a self-regulation survey, weekly reflections, final exam reflections, and interviews, all but one student indicated that the process of setting a goal weekly and especially reflecting on their actions during the week increased their self-regulation abilities. More than half …

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A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles Jan 2025

A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles

Faculty Publications

In multi-input systems, it is often necessary to quantify the contribution of each input to an output. Such contribution analysis is frequently performed using coherence. However, when correlation is present between inputs, existing coherence measures do not accurately quantify the contribution of individual inputs, except in special cases. Here we propose an expanded coherence framework that enables contribution analysis in any multi-input system, regardless of input correlation. We bridged the gap by defining three new coherence measures: component, excluded, and isolated coherence. Component coherence is an intermediate measure that decomposes measured output power into components attributable to inputs directly vs …

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Multidisciplinary Collaboration For The Integration Of Ai In Slavic Languages And Literatures: The Learning Lab Model, Anna Ivanov Dec 2024

Multidisciplinary Collaboration For The Integration Of Ai In Slavic Languages And Literatures: The Learning Lab Model, Anna Ivanov

Russian Language Journal

The Learning Lab at Harvard University's Derek Bok Center for Teaching and Learning employs graduate students as Media and Design Fellows (MDFs) to support innovative pedagogy in their departments. Over the last few years and in its Summer of AI, the Learning Lab has explored AI and its applications and implications in education. As such, the Lab, its staff, and its MDFs have developed and run well-structured, intellectually rigorous learning opportunities for many departments. For the Department of Slavic Languages and Literatures, the Learning Lab used AI in language and literature workshops. This paper presents a few case studies of …

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Narrative Engineering: Tools, Computational Structure, And Impact Of Stories, Michael A. Debuse Dec 2024

Narrative Engineering: Tools, Computational Structure, And Impact Of Stories, Michael A. Debuse

Theses and Dissertations

Computational Linguistics has a long history of applying mathematics to the grammatical and syntactic structure of language; however, applying math to the more complex aspects of language, such as narrative, plot, scenes, character relations, causation, etc. remains a difficult topic. The goal of my research is to bridge the narrative humanities with mathematics, to computationally grasp at these difficult topic, and help develop the field of Narrative Engineering. I view narrative and story with the same mathematical scrutiny as other engineering fields, to take the creativity and fluidity of story and encode it in mathematical representations that have meaning beyond …

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An Exploratory Analysis Of Within And Between-Testlet Local Item Dependence In A Medical School Admission Situational Judgment Test Using Exploratory Structural Equation Modeling, Ester Sampson Dec 2024

An Exploratory Analysis Of Within And Between-Testlet Local Item Dependence In A Medical School Admission Situational Judgment Test Using Exploratory Structural Equation Modeling, Ester Sampson

Theses and Dissertations

To use a Cronbach's alpha coefficient or IRT methods on measuring instruments, both unidimensionality and local item dependence (LID) conditions need to be met. Moreover, LID can potentially introduce an unintended additional dimension into the test at the expense of the constructs of interest. Situational judgment tests use testlet structures, and thus likely present degrees of LID. We explored the latent structure and degrees of local item dependence in a situational judgment test (SJT) used by a Western United States medical school (WMS) for admission purposes. I used a fully deidentified data set from a group of 560 examinees who …

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Development Of A Real-Time Convolution System To Simulate Speech In Different Rooms For The Study Of Vocal Strain, Bethany E. Wu Dec 2024

Development Of A Real-Time Convolution System To Simulate Speech In Different Rooms For The Study Of Vocal Strain, Bethany E. Wu

Theses and Dissertations

Due to prevalent vocal health issues in teachers, the acoustics of K-12 classrooms has become a topic of study in acoustics. One way to understand the effects of a classroom's physical space on speech is with vocal effort studies. This thesis aims to enable these studies, without the need to move a talker from room to room, by creating auralizations through real-time convolution of speech with oral binaural room impulse responses (OBRIRs). These auralizations can be used to test talkers inside an anechoic chamber as they experience speaking in different acoustical environments. A system that can successfully execute convolution in …

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Post-Processing National Water Model Long-Range Forecasts With Random Forest Regression In The Cloud To Improve Forecast Accuracy For Decision-Makers And Water Managers, Jacob Matthew Anderson Dec 2024

Post-Processing National Water Model Long-Range Forecasts With Random Forest Regression In The Cloud To Improve Forecast Accuracy For Decision-Makers And Water Managers, Jacob Matthew Anderson

Theses and Dissertations

Post-processing bias correction of streamflow forecasts can be useful in the hydrologic modeling workflow to fine-tune forecasts for operations, water management, and decision-making. Hydrologic model runoff simulations include errors, uncertainties, and biases, leading to less accuracy and precision for applications in real-world scenarios. We used random forest regression to correct biases and errors in streamflow predictions from the U.S. National Water Model (NWM) long-range streamflow forecasts, considering U.S. Geological Survey (USGS) gauge station measurements as a proxy for true streamflow. We used other features in model training, including watershed characteristics, time fraction of year, and lagged streamflow values, to help …

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Geochemical Characterization And Predictive Soil Mapping Of Ice-Free Regions In Antarctica, Rachel Willmore Dec 2024

Geochemical Characterization And Predictive Soil Mapping Of Ice-Free Regions In Antarctica, Rachel Willmore

Theses and Dissertations

Antarctic soils are formed by extreme climate, minimal biological activity, and diverse geological settings. This study analyzes 201 soil samples across four ice-free Antarctic Conservation Biogeographic Regions - North-west Antarctic Peninsula, Transantarctic Mountains, South Victoria Land, and North Victoria Land - to create a geochemical database (pH, EC, CEC, C and N, and ion concentrations) as well as to determine if there are consistent trends between geochemical properties and soil forming factors (SCORPAN). Despite variation in geochemical properties and SCORPAN covariates, some consistent trends emerged across all regions and individual Antarctic Conservation Biogeographic Regions. Using SCORPAN covariates and multiple linear …

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Contributions Of Glacier Meltwater To Water Resources And Water Quality Below The Ablating Coropuna Ice Cap In The Arid Peruvian Andes, Alexis Rowley Dec 2024

Contributions Of Glacier Meltwater To Water Resources And Water Quality Below The Ablating Coropuna Ice Cap In The Arid Peruvian Andes, Alexis Rowley

Theses and Dissertations

Rapidly retreating glaciers in the arid tropics are an invaluable resource for communities that depend on meltwater to support drinking water, agriculture, hydropower production, and mining. There is limited understanding of how glacier loss will impact regional water resources, groundwater flow paths, and water quality, especially during the dry season. The Nevado Coropuna volcano in Southern Peru has one of the largest remaining ice caps in the tropics, but has experienced rapid ice loss in the past few decades and is projected to disappear in the next century due to climate change. Located in the northern Atacama Desert, the arid …

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Using Two-Dimensional Terahertz Spectroscopy To Explore Vibrations, Magnetism, And Their Coupling, Megan Faux Biggs Dec 2024

Using Two-Dimensional Terahertz Spectroscopy To Explore Vibrations, Magnetism, And Their Coupling, Megan Faux Biggs

Theses and Dissertations

Terahertz (THz) light is at the resonant frequency of important fundamental excitations within crystalline materials such as carrier dynamics, phonons, and spin-wave excitations called magnons. THz light can be produced at high field strengths using optical rectification in nonlinear optical (NLO) crystals. N-benzyl-2-methyl-4-nitroaniline (BNA) is one such crystal commonly used to produce THz when pumping with 800 nm light. Here, we improve upon the design of the molecular building blocks of BNA by replacing a hydrogen atom with a fluorine atom, leading to improved THz generation and a higher crystal damage threshold. Later, we focus on using THz light to …

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Kinetic Modeling Of Bacteria Removal From Suspensions By Magnetic Nanoparticle Capture And Magnetic Separation, Bowen J. Houser Dec 2024

Kinetic Modeling Of Bacteria Removal From Suspensions By Magnetic Nanoparticle Capture And Magnetic Separation, Bowen J. Houser

Theses and Dissertations

This thesis investigates the kinetic modeling of bacteria removal from suspensions using magnetic nanoparticle (MNP) capture and magnetic separation. Functionalized magnetic nanoparticles, especially those coated with polydopamine (pDA), were employed to bind with various bacterial species in phosphate-buffered saline (PBS), apple juice, whole blood, and its components. By analyzing the capture efficiency and kinetics of capture across different bacterial species and mediums, we developed mathematical models describing the capture kinetics of bacteria by the pDA-MNPs. Experimental results demonstrated that pDA-coated MNPs achieved high capture efficiency with certain Gram-positive species like Staphylococcus aureus, and one Gram-negative species, Neisseria perflava; however, capture …

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New Chapters In An Old Book: New Discoveries In Transferrin's Blood Stream Modulators And Analytical Methods, Shelby Thomas Harris Dec 2024

New Chapters In An Old Book: New Discoveries In Transferrin's Blood Stream Modulators And Analytical Methods, Shelby Thomas Harris

Theses and Dissertations

Human serum transferrin is a 79 kDa glycoprotein responsible for the safe transport of iron throughout the blood stream. Transferrin binds up to two ferric ions in two domains known as the N-lobe and C-lobe respectively. Thus, there are four transferrin metalloforms: apo-Tf (with no iron bound), FeN-Tf (with one iron bound in the N-lobe), FeC-Tf (with one iron bound in the C-lobe) and holo-Tf(with two iron ions bound, one in each of the lobes). The two domains are homologous but feature differences in the kinetics and thermodynamics of iron binding and release. The two lobes are also different in …

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Time Reversal Delivery Of Long Duration Noise To A Targeted Location: Achieving Higher Amplitude While Maintaining A Desired Spectral Shape And Maximizing The Spatial Extent, Rylee Scott Russell Dec 2024

Time Reversal Delivery Of Long Duration Noise To A Targeted Location: Achieving Higher Amplitude While Maintaining A Desired Spectral Shape And Maximizing The Spatial Extent, Rylee Scott Russell

Theses and Dissertations

Time Reversal (TR) is a signal processing technique that can be used to focus acoustic waves to a specific location in space, with most applications aiming to create an impulsive focus. This study instead aims to focus long-duration noise signals using TR. This thesis seeks to generate higher amplitude noise at a desired location over an existing method of broadcasting equalized noise. Additionally, this thesis explores various characteristics associated with focusing long duration noise using TR. The dependence of the focal amplitude on the duration of the focused signal is explored as well as the implications of using multiple sources …

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Grain Boundary Solute Segregation Across The 5d Space Of Crystallographic Character, Lydia Harris Serafin Dec 2024

Grain Boundary Solute Segregation Across The 5d Space Of Crystallographic Character, Lydia Harris Serafin

Theses and Dissertations

Solute segregation in materials with grain boundaries (GBs) has emerged as a popular method to thermodynamically stabilize nanocrystalline structures. However, the impact of varied GB crystallographic character on solute segregation has never been thoroughly examined. This work examines Co solute segregation in a dataset of 7272 Al bicrystal GBs that span the 5D space of GB crystallographic character. Considerable attention is paid to verification of the calculations in the diverse and large set of GBs. In addition, the results of this work are favorably validated against similar bicrystal and polycrystal simulations. As with other work, we show that Co atoms …

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Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas Dec 2024

Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas

Theses and Dissertations

The presence of a non-liquefied crust overlying a liquefied layer has been found to have a significant effect on sand ejecta and surficial liquefaction damage, as observed by Ishihara (1985). Following the 2010-2011 Canterbury seismic sequence in New Zealand, almost no foundation deformation occurred in areas with liquefaction susceptible soils overlain by at least a 3 meter thick crust [1]. In contrast, the 2012 Emilia-Romagna earthquake in Italy provided surface evidence of liquefaction despite 6+ meter thick crusts. Several researchers have proposed liquefaction prediction models [e.g. LPI [2], Ishihara Curves [3], LSN [4], LPIISH [5] and the methods proposed by …

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Performance Prediction For Hub-Based Swarms, Puneet Jain Dec 2024

Performance Prediction For Hub-Based Swarms, Puneet Jain

Theses and Dissertations

Optimization problems lie at the core of improving performance in various tasks, ranging from day-to-day work scheduling to coordinating robots in a warehouse fulfillment center. Distributed swarm systems provide a robust and adaptive solution approach to many optimization problems. Instead of using one really sophisticated agent, multiple smaller less sophisticated agents can provide the flexibility to evaluate more options and still provide a "good" answer. This dissertation uses graphs to model, analyze, and simulate swarm behavior, primarily to predict the time-to-converge (TTC) and success probability. First, we use a bipartite model for the distributed best-of-N problem, and show how the …

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Discharge-To-Water Level Conversion Using Monthly Duration Curves (Dwl-Mdc): Enhancing The Utility Of The Geoglows Ecmwf Hydrological Model, Darlly Judith Rojas Lesmes Dec 2024

Discharge-To-Water Level Conversion Using Monthly Duration Curves (Dwl-Mdc): Enhancing The Utility Of The Geoglows Ecmwf Hydrological Model, Darlly Judith Rojas Lesmes

Theses and Dissertations

Flood early warning systems are crucial for disaster risk reduction strategies, enabling communities to take timely action against threats. However, the effectiveness of these systems depends on accurate and timely hydrological data, particularly river discharge and water level measurements. Unfortunately, many regions, face significant challenges in obtaining hydrological data, especially discharge data due to outdated rating curves, high equipment costs, and logistical constraints. Water level measurements, by contrast, offer reduced uncertainty and are often more accessible, providing an alternative for hydrological modeling in data-scarce regions. To address these limitations, we developed and validated the Discharge-to-Water Level Conversion Using Monthly Duration …

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Extracting Speech Content From High-Amplitude Background Machine Noise, Curtis L. Garner Dec 2024

Extracting Speech Content From High-Amplitude Background Machine Noise, Curtis L. Garner

Theses and Dissertations

The research presented in this dissertation aims to address the need for improved communication between heavy machinery operators and external personnel, aiming to improve safety and efficiency by overcoming the communication barriers posed by equipment noise and cab insulation. The primary purpose of this research was to develop a hands-free communication system that allows the operator to hear speech from outside the cab without requiring any personal communication devices like radios or headsets. Key objectives included effective speech extraction from ambient noise and accurate estimation of the location of the speaker. Operating without active user control, the system emphasizes clarity …

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Design And Synthesis Of Bimetallic Catalyst And Multifunctional Peptide Catalysis For Organic Synthesis And Synthesis Of Proteolysis Targeting Chimeras (Protacs) For Sphk1 And Sphk2, Mariur Rodriguez Moreno Dec 2024

Design And Synthesis Of Bimetallic Catalyst And Multifunctional Peptide Catalysis For Organic Synthesis And Synthesis Of Proteolysis Targeting Chimeras (Protacs) For Sphk1 And Sphk2, Mariur Rodriguez Moreno

Theses and Dissertations

In the first part of this dissertation (chapters 1-4) we discuss the development of bimetallic and monometallic palladium complexes scaffolded on 2-phosphinoimidazole ligands and their application to cross-coupling reactions. Specifically, we discovered a bimetallic Pd(II) dimer that performs a tandem arylation/annulation reaction to produce naphthalene products from aryl iodides and ketones (Chapter 2). We then show that bimetallic Pd(II) and Pd (I) complexes have different activity in different transformations and that the starting oxidation state of our catalysts is important for reactivity (Chapter 3). For example, we demonstrate that our Pd(I) dimer is much more active in Buchwald- Hartwig amination …

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Using Supervised Learning To Predict The Band Rank Of Braids, Juliana Moraes Dec 2024

Using Supervised Learning To Predict The Band Rank Of Braids, Juliana Moraes

Undergraduate Honors Theses

Supervised learning has emerged as a powerful tool for solving complex classification problems across various domains, including mathematical structures. In the realm of braid theory, an intriguing challenge involves determining the number of bands in a mathematical braid, which is crucial for understanding braid complexity and its applications. This thesis introduces an approach leveraging supervised learning to tackle this problem. Using different representations of a braid (namely braid words and Lawrence-Krammer representations), we train a supervised learning model to predict the number of bands in a given braid. The approach involves constructing a labeled dataset of braids with known band …

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Applications Of Phosphorus Geochemistry To Utah Lake, Jacob Barry Taggart Dec 2024

Applications Of Phosphorus Geochemistry To Utah Lake, Jacob Barry Taggart

Theses and Dissertations

This compilation of studies provides an examination of phosphorus dynamics in the suspended solids, water column, and lakebed sediments of Utah Lake, a large, shallow, and phosphorus-rich water body. The first study introduces a novel phosphorus microfractionation (P-MF) method designed for small samples of suspended solids and sediments. This method reveals that suspended solids in Utah Lake can have a significantly higher phosphorus content across most fractions compared to lakebed sediments, highlighting the importance of considering suspended solids in nutrient management strategies. The second study analyzes historical phosphorus mass and concentrations, demonstrating that water column phosphorus levels have remained stable …

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Intramolecular Styryl Diels-Alder (Isda) Reaction For Synthesizing Derivatives Of Anticancer Lignans, Kriti Shrestha Dec 2024

Intramolecular Styryl Diels-Alder (Isda) Reaction For Synthesizing Derivatives Of Anticancer Lignans, Kriti Shrestha

Theses and Dissertations

Intramolecular Styryl Diels-Alder (ISDA) cycloaddition reactions are used widely in synthesizing complex natural products. They help synthesize polycyclic cores and form new chiral centers in the molecule. Among such natural products, lignans are considered important biomedical molecules due to their numerous pharmacological properties, such as antitumor, hepatoprotective, insecticidal, antifungal, antihypertensive, sedative, antioxidant, and antiparasitic. Numerous researchers have published their work in trying to synthesize different lignans for medicinal purposes. However, the lignans are challenging to synthesize because of their complex tetralin cores. This project focuses on synthesizing the polycyclic core for the analogs of anti-cancer compounds with ISDA reaction. The …

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Synthesis Of Glycan Antigens For Therapeutic Antibodies And Glycoconjugate Vaccines, Synthesis Of An Inflammatory Pentasaccharide, And Design And Synthesis Of Ceragenins For Use In Medical Devices And Osteomyelitis, Shawn Gubler Dec 2024

Synthesis Of Glycan Antigens For Therapeutic Antibodies And Glycoconjugate Vaccines, Synthesis Of An Inflammatory Pentasaccharide, And Design And Synthesis Of Ceragenins For Use In Medical Devices And Osteomyelitis, Shawn Gubler

Theses and Dissertations

A promising approach in combatting infections from antibiotic resistant bacteria/fungi is using therapeutic monoclonal antibodies (mAbs) that can bind the outer surfaces of microbes. We have developed a synthetic vaccine platform that can rapidly generate mAbs against surface glycans from desired strains, such as lipopolysaccharides and capsular polysaccharides. To create therapeutic antibodies against Ruminococcus gnavus, Burkholderia multivorans, and Staphylococcus aureus, we synthesize glycan antigens from each strain that are necessary for use in our glycoconjugate vaccine platform. Blooms of the Gram-positive bacterium Ruminococcus gnavus have been correlated with inflammatory bowel disease, and recently a polysaccharide produced by this organism was …

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Sulfhydryl-Containing Compounds And Iron Homeostasis: Mechanisms Of Labile Iron Pool Dysregulation And Consequences For Cellular Health, Steven Lowell Mann Christiansen Dec 2024

Sulfhydryl-Containing Compounds And Iron Homeostasis: Mechanisms Of Labile Iron Pool Dysregulation And Consequences For Cellular Health, Steven Lowell Mann Christiansen

Theses and Dissertations

While iron's unique coordination chemistry and redox activity have resulted in its broad incorporation into biological systems, dysfunction in key iron-regulating mechanisms can transform these biochemical advantages into factors that contribute to several pathological conditions. This dissertation explores the complex interactions between iron and sulfhydryl-containing compounds (SCCs), with particular focus on glutathione's (GSH) role in stabilizing iron reactivity juxtaposed with homocysteine's (Hcy) ability to disrupt iron homeostasis and promote disease progression. Through rigorous biochemical analysis and experimentation, we demonstrate that Hcy disrupts iron regulation through several mechanisms: (1) Hcy competitively displaces protective iron-binding molecules in the Labile Iron Pool (LIP), …

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The Learner's Experience Using Augmented Reality, Michael Lionel Atkinson Dec 2024

The Learner's Experience Using Augmented Reality, Michael Lionel Atkinson

Theses and Dissertations

Augmented reality (AR) is a promising learning tool that has the potential to improve learning experiences in unique ways. While AR has been extensively studied in terms of learning outcomes, relatively little has been researched about the qualitative aspect of the learner experience and how that may inform better instruction. This multi-article, journal-ready dissertation addresses this gap. The first article is a review of the literature on what researchers have learned about AR in learning, systematically identifying six areas that appear salient yet underrepresented in the literature. The second article expands further upon this theme by conducting a qualitative study …

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Raman Characterization Of Elastomeric Materials, Shane Michael Drake Dec 2024

Raman Characterization Of Elastomeric Materials, Shane Michael Drake

Theses and Dissertations

Raman spectroscopy is often used for material identification but may be used for characterization. This document focuses on using Raman measurements to characterize polymers, specifically the curing and aging mechanism for hydroxyl-terminated polybutadiene (HTPB). HTPB is a well-known elastomer used in sealants, non-slip surfaces, rocket repellants and plastic explosives. Raman spectroscopy was used to monitor urethane linkages that form from curing HTPB with a cyanate curing agent to suggest a curing mechanism for HTPB. Since this polymer is highly susceptible to oxidation, the methods used to characterize curing were also used for the aging process to see if urethane breakages …

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Physics-Informed Transfer Learning For Process Control, Samuel Arce Munoz Dec 2024

Physics-Informed Transfer Learning For Process Control, Samuel Arce Munoz

Theses and Dissertations

In the realm of process control, managing complex systems with limited prior knowledge presents significant challenges, particularly in environments where traditional mechanistic models are either unavailable or computationally prohibitive. This work explores the integration of deep transfer learning with system identification and Model Predictive Control (MPC) to develop control strategies that are both data-efficient and computationally streamlined. Initially, Long Short-Term Memory (LSTM) networks are employed to create approximate MPC controllers by leveraging transfer learning from a source system to a target system, demonstrating that transfer learning can achieve comparable performance to traditional MPC methods with reduced training data. Building upon …

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Nonlinear Thomson Scattering In An Intense Tightly Focused Ultrashort Laser Pulse, Yance Sun Dec 2024

Nonlinear Thomson Scattering In An Intense Tightly Focused Ultrashort Laser Pulse, Yance Sun

Theses and Dissertations

We investigate nonlinear Thomson scattering generated by intense laser pulses focused in noble gases. Electrons are ionized from low-density helium or argon early during the laser pulse and scatter light out the side of the focus. We measure fundamental, second, and third harmonic light focus over nearly the entire emission sphere. We investigate the influence of electron bunching, when individual atoms ionize multiple electrons sequentially as the laser field increases early during the laser pulse. Simulations suggest that correlation between electron positions for the ten electrons ionized from argon should distort the spatial pattern of nonlinear Thomson scattering relative to …

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