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Insights Into Factors Influencing Radical Coupling Chemistry Of Monolignols During Lignification And Induced Changes In Plant Secondary Metabolism, Rachel Poornima Sutherland

Theses and Dissertations--Chemistry

Lignin is a complex aromatic biopolymer and an important constituent in plant cell walls. The process of lignin biosynthesis, known as lignification, is poorly understood and challenging to study but has important implications in a variety of fields including sustainable energy, bioengineering, and materials science and is therefore of interest to pursue. In the final stage of lignification, H-, G-, and S-monolignols are oxidized by laccase and peroxidase enzymes to generate radical species that couple to form dimers and further oligomeric species to ultimately produce the lignin polymer. Biomimetic lignin model systems utilize in vitro oxidative coupling reactions as an …

Theoretical And Applied Considerations In Dynamical Sampling, Brendan Miller

Graduate Research Theses & Dissertations

Dynamical sampling is an area of mathematics which studies the theory and applications of signals evolving through time, as well as the stable recovery of said signals from spatiotemporal measurements. This manuscript is devoted to problems which arise as theoretical considerations in signal recovery and as applications of using space-time measurements as opposed to static measurements.

For the former, we consider the problem of recovering an evolving signal via space-time measurements at irregular time intervals. To do so, we generalize the classic Kadec $1/4$ theorem using techniques of Banach $L^1(\R)$-modules. For the latter, we show how dynamical samples can be …

Universality Of Complex Valued Neural Networks, Sauvik Mondal

Graduate Research Theses & Dissertations

Neural networks have become central to modern natural science. One of the key components of these networks is the choice of a suitable activation function. In this manuscript, we explore the selection of an optimal activation function in the context of complex-valued neural networks. We aim to characterize the activation functions $\sigma\colon \mathbb{C} \rightarrow \mathbb{C}$, where each neuron performs the operation $\mathbb{C}^N \rightarrow \mathbb{C}$, defined as: $z \mapsto \sigma(b + w^Tz)$. First, we briefly discuss the real-valued counterpart, including the importance of function approximation and the renowned universal approximation theorem. Subsequently, we examine various criteria for complex activation functions that …

Long Term Dynamics Of A Stage Structured Population Model With Nonlocal Dispersal, Md Yasin

Graduate Research Theses & Dissertations

This thesis is based on the 2023 paper “Dynamics of Classical Solutions of a Two-Stage Structured Population Model with Nonlocal Dispersal.” We study the long-term behavior of a population with two life stages, juvenile and adult, moving across space using nonlocal dispersal mechanism. The main goal is to understand the conditions under which the species survives or goes extinct on the long run. This is determined by a key value called the principal spectrum point, λp.

First, using results from the literature on existence of solutions for general initial value problems on Banach spaces, we establish that for any given …

Rise Or Retreat: The Role Of Appraisal And Goal Orientations In Leader Engagement, Haleigh Broucher

Graduate Research Theses & Dissertations

This dissertation examines how leaders psychologically interpret developmental challenges as threats or challenges, and how these interpretations shape engagement. Furthermore, I propose that these processes are shaped by mastery-approach and mastery avoidance orientations. Study 1 manipulated the presence of developmental challenges to test causal pathways. Results indicated that developmental challenges increased threat appraisal but not challenge appraisal, and threat was negatively associated with absorption. Study 2 found the opposite pattern: challenge appraisal, not threat appraisal, explained engagement. Relative importance analysis showed that challenge appraisal accounted for nearly all explained variance in engagement (97.6%). There was no significant moderation of mastery …

Size Dependent Thermodynamic Properties Of Dppc, Zhenghao Pan

Graduate Research Theses & Dissertations

This study explores the viability of measuring the melting transition behavior in a simple unilamellar vesicle (LUV/SUV) liposome (DPPC surfactant) system using size data from Dy- namic Light Scattering (DLS). The melting transition of phospholipid membranes has been a focal point of studies in biological systems. Conventionally, the transition temperature of a membrane system is measured using either spectroscopy or Differential Scanning Calorimetry (DSC). By assuming that the bilayer volume is conserved, it is shown that DLS provides a transition signal comparable to that of DSC and aligns with known data. The data are fit- ted using Van’t Hoff’s equation. …

Characterization Of A Large-Scale Electrohydrodynamic Vortex Confinement Flow For Particle Agglomeration, Sanjay Dangi

Graduate Research Theses & Dissertations

With industrialization and the increasing use of microplastics and nanoparticle-based products, the concentration of fine particulate matter (PM2.5) in the biosphere has increased due to the disposal of manufacturing waste and expired parts. If inhaled, PM2.5 can have detrimental health effects, as these particles can travel deep into the lungs and even penetrate blood vessels. Conventional fabric filters used for indoor air quality control have drawbacks, including the need for periodic filter replacement and a high-pressure drop across the filter over time, which leads to increased power consumption. In power plants, electrostatic precipitators (ESPs) are primarily used to collect fly …

Methods For Finding High Quality And Optimal Solutions Of Binary Quadratic Optimization Problems, James Haas

Graduate Research Theses & Dissertations

BiqAlps is an extension of the BiqCrunch project that leverages its bounding procedures within a computer cluster environment. The primary goal of this work was to investigate whether distributing the branch-and-bound tree search across multiple CPUs could improve solve times. While some problem instances demonstrated speedups of up to fivefold, others showed no measurable improvement, revealing that parallelization benefits are problem-dependent.

Beyond parallelization, BiqAlps introduces enhanced heuristics for generating high-quality initial solutions and refining existing ones. Additionally, the framework explores the impact of propagating triangle inequality cuts to child nodes during search, with the aim of accelerating bounding processes and …

Cubic Blaschke Products, Alexandra Hill

Graduate Research Theses & Dissertations

It is well known that Blaschke products can be classified as elliptic, hyperbolic, or parabolic. Based on the classification of the Blaschke product, we know that the Julia set is either the entire unit circle or a Cantor subset of the unit circle. For unicritical Blaschke products of degree d, it has been shown that the parabolic functions are parameterized by an epicycloid with d-1 cusps, with the interior of the epicycloid giving rise to the elliptic parameters, and the relative complement of the epicycloid within the unit disk providing the hyperbolic parameters. In this dissertation, we study in more …

Experimental Demonstration Of A Metallic Sub-Terahertz Structure For High-Gradient, High-Efficiency Acceleration, Brendan Leung

Graduate Research Theses & Dissertations

Future accelerator facilities are increasingly constrained by the cost and footprint of conventional radiofrequency technology. Advancing both accelerating gradient and beam-to-wake energy transfer efficiency in the sub-terahertz (sub-THz) regime offers a credible path toward compact machines. Short wavelengths strengthen beam–structure coupling and enable small-aperture, high-impedance geometries; paired with tailored drive-beam current profiles, they can simultaneously raise gradient and transformer ratio.

This dissertation reports the design, fabrication, and beam testing of a sub-THz structure-wakefield accelerating (SWFA) device evaluated at the Argonne Wakefield Accelerator (AWA). The emittance-exchange (EEX) beamline was used to generate prescribed longitudinal current profiles in two modes: (i) a …

Constraining The Timing And Degree Of Metamorphism In The Echo Canyon Region: Evidence For A Cryptic Contact Aureole, Keanu Montañez

Graduate Research Theses & Dissertations

Local occurrences of andalusite and kyanite in Echo Canyon, within the Funeral Mountains metamorphic corecomplex, overprint chlorite-grade phyllites and reveal the presence of a hidden pluton and its contact aureole. Phase equilibria models indicate minimum conditions of 0.45 GPa and 535 °C in the highest-grade zone of the aureole, with significantly higher temperatures than previously estimated for the area. This study applied phase equilibria pressure-temperature modeling, petrography, Raman spectroscopy, and ⁴⁰Ar/³⁹Ar geochronology on muscovite to characterize this anomalous metamorphism and to place it within a revised tectonic framework. Two potentially coeval prograde metamorphic events have been recognized based on petrographic …

Climate Migration And Urban Survival: Evidence From Chittagong’S Slums, Mohammad Nur Nobi

Graduate Research Theses & Dissertations

This study examines the impact of climate change on rural-to-urban migration in Chittagong, Bangladesh. Based on a primary survey of 400 respondents across 35 slums in the country's second-largest city, the analysis employs two estimation methods: a multinomial logit model to assess the influence of climate-related factors on migration decisions, and a logit model to evaluate the impact of migration on the living conditions of migrants. The results show that individuals involved in ‘agriculture and daily labor’ are most likely to migrate. Compared to the base category (‘Other Reasons’) for migration, the odds ratios for ‘floods’, ‘droughts’, and ‘better job …

Sensitivity Studies Of Vector-Like Quark (Vlq) Pair Production In The Full-Hadronic Channel At The High-Luminosity Large Hadron Collider (Hl-Lhc) And A 10 Tev Muon Collider, Olabisi Olayinka

Graduate Research Theses & Dissertations

Vector-like quarks (VLQs) appear in various extensions of the Standard Model that consider a new strongly interacting sector to resolve the fine-tuning problem. These new particles can provide radiative corrections to the Higgs mass while also having electroweak-singlet masses. This latter property would allow them to escape existing constraints from Higgs boson measurements and electroweak precision data, which disfavor the existence of a fourth generation of quarks.

VLQ can be produced at colliders, with a variety of production modes and decay mechanisms open for study. In this work, we investigate the pair production of VLQ Tops (T), which are assumed …

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das

Theses and Dissertations--Chemistry

In absence of O₂ as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times less efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes were able to generate H₂ and a chemiosmotic potential able to drive energy demanding reactions such as CO₂ or N₂ fixation. These observations raised concerns as production of high energy reductants (H₂) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was …

Towards Automating The Study And Discovery Of Electroactive Π-Conjugated Molecules, Rebekah Ann Duke-Crockett

Theses and Dissertations--Chemistry

Chemistry is entering a new paradigm of automation and data-driven discovery. Automated discovery is grounded in well-curated “big data.” As generative and predictive models fueled by simulation data see growing success, emerging robotic automation enables the generation of unprecedented volumes of experimental data. Automation-powered, data-driven approaches hold tremendous potential for groundbreaking insights and innovations, particularly in the study and discovery of electroactive π-conjugated molecules. Realizing this potential, however, requires democratizing chemical data and the automation needed to generate and use it. There is a need to expand access to the tools for findable, accessible, interoperable, and reusable (FAIR) data management …

Design And Synthesis Of Novel Ligands For Bioorthogonal Catalysis, Asymmetric Synthesis, And Ferromagnetic Behavior, Alexander G. Olivelli

Theses and Dissertations--Chemistry

Small molecule metal complexes have diverse applications including usage as catalysts, single molecule magnets, photosensitizers and pharmaceuticals. The first research project in this work reports a new ligand which dimerizes upon coordination to afford a trinuclear Cu(I) complex. Due to the coordination geometry of the Cu(I) metal centers, paired with the strong nitrogen coordinating groups, the resulting complex is resistant to oxidation even in the presence of strong oxidants. The complex is shown to be efficient in the CuAAC reaction and used to tag anticancer drug candidates in vitro. The next project focuses on a series of amidine-based ligands featuring …

Machine Learning Models For Molecular-Based Functional Organic Materials, Moses Ogbaje

Theses and Dissertations--Chemistry

Organic semiconductors (OSC) are of interest for a wide range of flexible optoelectronics applications, including transistors, solar cells, and sensors, to name a few. Despite their promise, the design and optimization of OSC pose significant challenges due to the complexity of the structures of the molecular building blocks, varied packing configurations of these building blocks in the solid state, which impacts the optical and electronic response, and sensitivity of the solid-state packing to material processing conditions. Accurately predicting the solid-state properties of OSC traditionally requires high-level quantum mechanical methods. These methods, however, can be computationally demanding, particularly for large molecules …

Investigation Of D-Π-A Re (1) Complexes For The Homogenous Photocatalytic Reduction Of Co2, Ryan M. Chafin

Theses and Dissertations--Chemistry

Increasing anthropogenic emission of CO₂ into the atmosphere is a global issue that shows no signs of deceleration due to the current trends in dependencies on fossil fuels for energy demand. Although deleterious in nature, this greenhouse gas can serve as a useful feed-stock for the production of small-carbon-chain commercial chemicals if the factors owing to its inertness can be overcome. Fortuitously, CO₂’s chemically inert nature is already circumvented in nature through an elegant cascade of biochemical reactions known as photosynthesis, which nearly all plants and some families of bacteria exploit to produce simple sugars for metabolic …

Construct Validity Of The Cognitive Assessment System- 2nd Edition: Rating Scale: Comparisons With The Learning Behaviors Scale, Cameron Graham

Masters Theses

Cognitive assessment instruments, such as the Cognitive Assessment System Second Edition: Rating Scale (CAS2: Rating Scale), are frequently utilized by school psychologists to assess children’s cognitive abilities and psychopathology. However, the CAS2 and the CAS2: Rating Scale have little research regarding their psychometric properties. The present thesis examined the construct validity of the CAS2: Rating Scale in comparison to the Learning Behaviors Scale (LBS). Canivez and Gaboury (2013), while assessing the construct validity of the CAS, found that for the ADHD group, the LBS Attitude Toward Learning, Attention/Persistence, and Strategy/Flexibility scores and the CAS Planning and Attention scores were significantly …

Implementation Of Competency-Based Education In East Central Illinois, Cheyenne Warman-Neal

Masters Theses

The purpose of this study was to investigate the perceptions of the effectiveness of competency-based education in a rural school district located in East Central Illinois. The researcher examined the first phase of implementation of Competency-Based Education (CBE) in both middle and high schools of this school district through surveys of students and teachers, along with students’ Measure Academic Proficiency or Performance (MAP) Test scores in ELA and Math. MAP score data was obtained from 669 students for ELA Growth and 699 students for Math Growth. Survey data was obtained from 70 high school students and six teachers. Student survey …

Effects Of Perceived Procedural Justice On The Relationship Between Visa Application Outcome And Psychological Distress: Evidence From Ghanaians And Nigerians Applying For U.S. Student Visas, Harriet Swanzy-Baffoe

Masters Theses

Visa interviews are not just bureaucratic processes; they can have significant psychological effects on applicants. This study examined the impact of U.S. student visa outcomes on psychological distress among West African applicants, with particular attention to perceptions of procedural justice during the interview process. The study surveyed 203 Ghanaian and Nigerian individuals who had previously applied for a U.S. student visa. Psychological distress was measured using the Impact of Event Scale-Revised (IES-R), and perceptions of fairness were measured with a custom-developed Procedural Justice Scale. Independent samples t-tests showed that denied applicants reported significantly higher distress, although elevated symptoms were also …

Targeted Mitigation Strategies To Reduce Secondary Emissions In Co2 Capture Systems, Keemia Abad

Theses and Dissertations--Chemistry

Global CO₂ emissions from industrial, power generation and transportation sources has led to the call for increased implementation of carbon capture strategies. The most developed of these is point source carbon capture, which refers to the process of capturing CO₂ directly from large (point) source emitters, before the CO₂ is released into the atmosphere. The challenge becomes separating CO₂ from the other components of the emitted gas, mainly nitrogen. These CO₂ capture processes typically involve the use of aqueous solutions of amines to absorb (capture) CO₂ from the gas stream, where the CO₂ and the …

Exploring The Relationships Between Molecular Structure And Crystal Packing In Small-Molecule Organic Semiconductor Materials, Dean A. Windemuller

Theses and Dissertations--Chemistry

Organic semiconductor materials (OSCs) are rapidly becoming a vital part of the technological landscape. They possess unique properties that make them attractive for the electronics industry. Relatively low-temperature and low-cost processing are a large part of the promise of OSCs. Perhaps more importantly, organic materials can be modified in a relatively straightforward manner, presenting an opportunity for them to be tuned and adapted to a variety of purposes and applications. Polycyclic aromatic hydrocarbons (PAHs) form a large group within the field of OSC research. Some of the most promising high-performance materials in this category to-date are acenes and heteroacenes. This …

Effects Of A-Site Cation Structure And B-Site Metal On Optical And Electronic Properties Of 2d Ruddlesden-Popper Phase Tin-Based Hybrid Perovskites, Henry Pruett

Theses and Dissertations--Chemistry

Organic metal halide perovskites (HPs) are attractive materials for a variety of electronic applications due to their low cost, tunable band gaps, excellent charge transport properties, and high photoluminescence efficiency. As such, HPs are being investigated for use in solar cells, photodetectors, X-ray detectors, light emitting diodes, field effect transistors, lasers, resistive random-access memory, etc. Currently the most popular metal used in HPs is lead, but the use of lead comes with the potential for heavy metal exposure. Tin-based perovskites offer a less hazardous alternative, but their optoelectronic properties lag behind those of lead and less work has been done …

Limitations Of Scientific Articles And Navigated Future Directions With Llm And Rag, Ibrahim Al Azher

Graduate Research Theses & Dissertations

Traditional Topic Modeling approaches, as well as zero-shot, few-shot, and fine-tuned Large Language Models (LLMs), have struggled to generate topics alongside relevant text from diverse sources, particularly sections such as Limitations. This thesis investigates automated methods for analyzing and synthesizing key sections of scientific articles using LLMs, exploring multiple dimensions of scientific text analysis.

First, LimTopic is introduced as a method for extracting and modeling the limitations sections of research papers. By integrating LLM-based topic generation with BERTopic, the approach generates descriptive titles and concise summaries that highlight the boundaries and shortcomings of studies, ultimately guiding future research directions.

Second, …

Green's Functions And Fixed Points Of Quasiregular Maps, Mark Broderius

Graduate Research Theses & Dissertations

This dissertation is on the dynamics of planar quasiregular maps of degree 2. These maps have three parameters. One of these parameters determines the distortion, one of them determines the orientation, and the last one is a shift parameter. Our first objective is to construct a new dynamical version of Green's functions for these maps. These functions provide information about the escaping sets of our quasiregular maps and are used to prove topological results about them. We show that the boundary of the escaping set is either connected or consists of infinitely many components. Additionally, we prove that if one …

Effect Of Universal Health Coverage On Neonatal Mortality Rate In Sub-Saharan Africa: Addressing Missing Data In Health Indicators, Elizabeth Nalule Arihoona

Graduate Research Theses & Dissertations

This study utilizes two mixed-effects models to examine the effect of Universal Health Coverage on Neonatal Mortality Rate (NMR) in 30 countries of Sub-Saharan Africa from 2000-2019 while addressing the missing data in health indicators. Using natural cubic spline interpolation, I impute the missing values in the health coverage indices to preserve the location- specific trends of the data. Findings indicate that among the health Coverage indices, only Index1, which directly relates to coverage of maternal, newborn and child health services is significantly associated with reduced NMR. While higher Current Health Expenditure is associated with reduced NMR, a higher share …

X-Ray Standing-Wave Fluorescence Study Of The Interaction Of An Anti-Microbial Peptide With A Supported Phospholipid Bilayer, Gobind Basnet

Graduate Research Theses & Dissertations

To understand the mechanism by which anti-microbial peptide penetrates biological membranes,the study uses artificial supported lipid bilayers (SLBs) deposited on solid substrates. These bilayers were prepared from a lipid mixture of 1,2-dimyristoyl-sn-glycero-3- phosphocholine (DMPC)and 1,2-dimyristoyl-sn-glycero-3-phospho-(1’-rac-glycerol (DMPG) in a 10:1 molar ratio and were incubated both with and without indolicidin. Additionally, bilayers were studied after incubation with a labeled form of indolicidin, which involved attaching a 1.8 nm diameter gold nanoparticle to the peptide’s terminal arginine group.

X-ray reflectivity (XRR) was employed to identify structural differences between SLBsincubated with indolicidin and those without it. The introduction of gold labeling facilitated the …

Design, Synthesis, And Evaluation Of Di-Peptide Probes For Stoichiometric Quantitative Analysis Of Antibodies, Taylor Gladson

Graduate Research Theses & Dissertations

Quantitative information on biomarkers is a decisive factor in a wide range of situations concerning individual and public well-being. Under certain circumstances, the availability of accurate quantitative information can even become a matter of life or death. Therefore, the ability to make quantitative measurements in point-of-care (POC), do-it-yourself (DIY), and limited resource settings (LRS) is crucial for diagnostics, disease management, food safety, biomedical research, forensics, and other areas.In the work, we develop a POC/DIY/LRS-compatible platform for unambiguous (yes/no type) quantitative analysis of antibodies. The heart of the approach is negative cooperativity-based target – probe binding. The binding modality yields a …

Meaningful Legislative Conflict: The Role Of Party Competition, Nader Omar Alghoul

Graduate Research Theses & Dissertations

This dissertation explores the influence of legislative conflict, defined by party polarization, relational animosities, and majority size, on legislative productivity in the U.S. Congress. While prior studies have focused on party polarization, divided government, and relational conflict, this research broadens the analysis by incorporating majority size as a key determinant of legislative accomplishment. The research will affirm that moderate polarization sharpens policy debates and enhances productivity, while extreme polarization, particularly when combined with significant relational conflict, results in legislative gridlock. Importantly, this research adds majority size to the amalgam of conflict and uncovers a curvilinear pattern: modest majorities improve legislative …