Physical Sciences and Mathematics Commons^™

Geophysical Techniques Used For The Analysis And Prediction Of Soil Strength And Mechanical Behavior, Matthew A. Hurley

Theses and Dissertations--Civil Engineering

Determining soil properties involves extensive laboratory testing of samples at discrete timing and location. Non-destructive analysis methods, such as electrical and seismic, presents alternatives to means of gathering soil properties accompanied with increased flexibility due to spatial and temporal applications. This research examined the ability of seismic wave data to predict soil behavior such as stress-strain and pore pressures using a modified version of Duncan and Chang (1970). Friction angle predictions were also analyzed using shear wave velocity and a modified form of the Santos and Gomez-Correria (2001) equation. This research also analyzed the use of electrical data to predict …

Artificial Intelligence And Soft Computing In Smart Structural Systems, Sajad Javadinasab Hormozabad

Theses and Dissertations--Civil Engineering

Next-generation smart cities are the key feature in the next chapter of human life. Cities that employ innovative and technology-driven solutions to improve the sustainability, resilience, prosperity, and amenity of the community are considered smart cities. Development of smart cities requires fundamental innovations in many technical and technological aspects including those contributing to smart structures. Smart technologies improve the structural performance against natural disasters like earthquakes, hurricanes, tornados, and promote the sustainability of structural systems. Next-generation smart structures encompass a variety of technologies including Structural Control (SC) and Structural Health Monitoring (SHM). SC covers methodologies and technologies that modify the …

Proctoring And Apps In College Algebra, Cynthia M. Shelton

Theses and Dissertations--Education Sciences

The pandemic forced more instructors and students to move to online learning. For the first time, many experienced a loosening of the reigns and were forced to allow students to submit non-proctored work. Many may have questioned what students really learned in the year 2020. Many college math course competencies emphasize procedures. Now that apps can do that for students, where does that leave math instructors? Additionally, online instruction has exploded over the last decade and has challenged the teaching of college mathematics. While online instruction opens the door to access, it does beg the question of whether students complete …

Investigation Of Multidrug Efflux Transporter Acrb In Escherichia Coli: Assembly, Degradation And Dynamics, Prasangi Irosha Rajapaksha

Theses and Dissertations--Chemistry

The Resistant Nodulation Division (RND) super family member, tripartite AcrA-AcrB-TolC efflux pump, is a major contributor in conferring multidrug-resistance in Escherichia coli. The structure of the pump complex, and drug translocation by functional rotation mechanism have been widely studied. Despite of all these data, the dynamics of the assembly process of the pump and AcrB during functional rotation in the process of drug efflux remains poorly understood. My thesis focuses on understanding the pump assembly process, dynamics of AcrB in functional rotation mechanism, and also investigate the mechanism of degradation of AcrB facilitated by a C-terminal ssrA tag.

In the …

Determining Material Structures And Surface Chemistry By Genetic Algorithms And Quantum Chemical Simulations, Josiah Jesse Roberts

Theses and Dissertations--Chemistry

With the advent of modern computing, the use of simulation in chemistry has become just as important as experiment. Simulations were originally only applicable to small molecules, but modern techniques, such as density functional theory (DFT) allow extension to materials science. While there are many valuable techniques for synthesis and characterization in chemistry laboratories, there are far more materials possible than can be synthesized, each with an entire host of surfaces. This wealth of chemical space to explore begs the use of computational chemistry to mimic synthesis and experimental characterization. In this work, genetic algorithms (GA), for the former, and …

Mass Spectrometry Method Development For The Discovery And Characterization Of Secondary Metabolites, Zachary Kelley

Theses and Dissertations--Chemistry

Secondary metabolites are organic compounds produced by an organism for reasons other than growth and development. In plants, secondary metabolites generally act as defense agents produced to deter predators and inhibit other competitive species. For humans, these compounds can often have a beneficial effect and are pursued and utilized as natural pharmaceuticals. The development of sensitive, high-throughput analytical screening methods for plant derived metabolites is crucial for natural pharmaceutical product discovery and plant metabolomic profiling. Here, metabolomic profiling methods were developed using a microfluidic capillary zone electrophoresis device and evaluated against traditional separation approaches. An alkaloid screening assay was constructed …

Synthesis, Crystal Engineering, And Material Properties Of Small-Molecule Organic Semiconductors, Emma Holland

Theses and Dissertations--Chemistry

Small-molecule organic materials are of increasing interest for electronic and photonic devices due to their solution processability and tunability, allowing devices to be fabricated at low temperature on flexible substrates and offering utility in specialized applications. This tunability is the result of functionalization through careful synthetic strategy to influence both material properties and solid-state arrangement, both crucial variables in device applications. Functionalization of a core molecule with various substituents allows the fine-tuning of optical and electronic properties, and functionalization with solubilizing groups allows some degree of control over the solid- state order, or crystal packing. These combinations of core chromophores …

Rational Design Of Small Molecule Disruptors Of Protein-Protein Interactions: Pd-1/Pd-L1; C-Myc, Arid4b, Samuel Ofori

Theses and Dissertations--Chemistry

Protein-protein interactions (PPIs) are vital to many biological processes, including gene expression, and immune reactions to pathogens. There are approximately 650,000 PPIs in humans with pertinent physiological functions. Aberrant expression of PPIs lead to improper function and contribute to a plethora of disease conditions including cancer. Thus, PPIs represent an enormous target space for drug discovery and chemical probes. Direct targeting of clinically relevant PPIs with small molecules remains an unmet medical need. Development of small-molecule inhibitors of PPIs is a challenging enterprise and in most cases considered undruggable due to large protein surfaces, lack of deep binding pockets and …

Developing Synthetic Strategies For Multifaceted Applications Of Stable Gold-Based Complexes, Randall Tyler Mertens

Theses and Dissertations--Chemistry

Development of stable gold-based complexes has been a rapidly advancing field due to the popularity of gold complexes, particularly for use in biomedical research and catalytic transformations. Given that auranofin, a gold(I) complex with FDA approval for the treatment of rheumatoid arthritis is used in the clinic, the development of stable gold-based molecules of clinical relevance is urgently needed. Herein are reported, synthetic strategies used for the development of new classes of gold(I) and gold(III) complexes for advancement in mitochondrial modulation for use as chemotherapeutics as well as application to gold catalysis due to the unique geometry of complexes presented …

Flavin Modification And Redox Tuning In The Bifurcating Electron Transfer Flavoprotein From Rhodopseudomonas Palustris: Two Arginines With Different Roles, Nishya Mohamed-Raseek

Theses and Dissertations--Chemistry

Electron bifurcation is considered as a third fundamental mode of energy conservation mechanism in addition to two well-known mechanisms, substrate level phosphorylation and Oxidative phosphorylation, in electron bifurcation endergonic and exergonic redox reactions are coupled. The newly discovered flavin based electron bifurcation in electron transfer flavoproteins (ETFs) helps to reduce low potential ferredoxin, which provides electrons to drive biologically demanding reactions such as atmospheric dinitrogen fixation in diazotroph and methane production in methanogens.

Current research demonstrates the capacity for electron bifurcation in the Rhodopseudomonas palustris ETF (RpalETF) system. RpalETF contains two chemically identical but functionally different FADs: …

Enhancing Agroecosystem Phosphorus Management: Root Phenotyping And Decomposition For Improved Phosphorus Cycling, Rebecca Kay Mcgrail

Theses and Dissertations--Plant and Soil Sciences

Plant roots are often overlooked when making nutrient management decisions. Evaluating differences in P acquisition strategies and cycling resulting from years of shoot-specific plant breeding will aid in reducing fertilizer inputs, with the ultimate goal of improving economic sustainability of crop production and preservation of ecosystem services. To achieve this goal, this research screened a diverse panel of winter wheat cultivars that included old and modern, dwarfed and wild type varieties for physical and chemical root phenotypes related to P acquisition. Old cultivars had larger root systems with more roots that grew two times faster than intermediate/modern cultivars. Wild type …

The Plus-Minus Davenport Constant Of Finite Abelian Groups, Darleen S. Perez-Lavin

Theses and Dissertations--Mathematics

Let G be a finite abelian group, written additively. The Davenport constant, D(G), is the smallest positive number s such that any subset of the group G, with cardinality at least s, contains a non-trivial zero-subsum. We focus on a variation of the Davenport constant where we allow addition and subtraction in the non-trivial zero-subsum. This constant is called the plus-minus Davenport constant, D_±(G). In the early 2000’s, Marchan, Ordaz, and Schmid proved that if the cardinality of G is less than or equal to 100, then the D_±(G) …

Some Proofs Regarding Minami Estimates And Local Eigenvalue Statistics For Some Random Schrödinger Operator Models, Samuel Herschenfeld

Theses and Dissertations--Mathematics

We provide three proofs on different, but related models in the field of random Schrödinger operators. All three results are motivated by the desire to extend results and techniques on eigenvalue statistics or Minami estimates (an essential ingredient Poisson eigenvalue statistics).

Chapters 2 and 4 are explorations of the only two known techniques for proving Minami estimates for continuum Minami estimates. In Chapter 2, we provide an alternative and simplified proof of Klopp that holds in d = 1. Chapter 4 is an application of the techniques of Dietlein and Elgart to prove a Minami estimate for finite rank lattice …

Novel Methods For Characterizing Conditional Quantiles In Zero-Inflated Count Regression Models, Xuan Shi

Theses and Dissertations--Statistics

Despite its popularity in diverse disciplines, quantile regression methods are primarily designed for the continuous response setting and cannot be directly applied to the discrete (or count) response setting. There can also be challenges when modeling count responses, such as the presence of excess zero counts, formally known as zero-inflation. To address the aforementioned challenges, we propose a comprehensive model-aware strategy that synthesizes quantile regression methods with estimation of zero-inflated count regression models. Various competing computational routines are examined, while residual analysis and model selection procedures are included to validate our method. The performance of these methods is characterized through …

Innovative Statistical Models In Cancer Immunotherapy Trial Design, Jing Wei

Theses and Dissertations--Statistics

A challenge arising in cancer immunotherapy trial design is the presence of non-proportional hazards (NPH) patterns in survival curves. We considered three different NPH patterns caused by delayed treatment effect, cure rate and responder rate of treatment group in this dissertation. These three NPH patterns would violate the proportional hazard model assumption and ignoring any of them in an immunotherapy trial design will result in substantial loss of statistical power.

In this dissertation, four models to deal with NPH patterns are discussed. First, a piecewise proportional hazards model is proposed to incorporate delayed treatment effect into the trial design consideration. …

Estimating And Testing Treatment Effects With Misclassified Multivariate Data, Zi Ye

Theses and Dissertations--Statistics

Clinical trials are often used to assess drug efficacy and safety. Participants are sometimes pre-stratified into different groups by diagnostic tools. However, these diagnostic tools are fallible. The traditional method ignores this problem and assumes the diagnostic devices are perfect. This assumption will lead to inefficient and biased estimators. In this era of personalized medicine and measurement-based care, the issues of bias and efficiency are of paramount importance. Despite the prominence, only few researches evaluated the treatment effect in the presence of misclassifications in some special cases and most others focus on assessing the accuracy of the diagnostic devices. In …

Machine Learning And Bioinformatic Insights Into Key Enzymes For A Bio-Based Circular Economy, Japheth E. Gado

Theses and Dissertations--Chemical and Materials Engineering

The world is presently faced with a sustainability crisis; it is becoming increasingly difficult to meet the energy and material needs of a growing global population without depleting and polluting our planet. Greenhouse gases released from the continuous combustion of fossil fuels engender accelerated climate change, and plastic waste accumulates in the environment. There is need for a circular economy, where energy and materials are renewably derived from waste items, rather than by consuming limited resources. Deconstruction of the recalcitrant linkages in natural and synthetic polymers is crucial for a circular economy, as deconstructed monomers can be used to manufacture …

Residual Spatial Autocorrelation In Macroecological And Biogeographical Modeling: A Review, Guetchine Gaspard

Theses and Dissertations--Geography

Macroecological and biogeographical modelers have predicted the distribution of species across space relying on the relationship between biotic processes and environmental variables. Such a method employs data associated, for instance, with species abundance or presence/absence, climate, geomorphology, and soils. Statistical analyses found in previous studies have highlighted the importance of accounting for the effects of spatial autocorrelation (SAC), which indicates a level of dependence between pairs of nearby observations. A consensus has existed that residual spatial autocorrelation (rSAC) can substantially impact modeling processes and inferences. However, more emphasis should be put on identifying the sources of rSAC and the degree …

Dimension Reduction Techniques In Regression, Pei Wang

Theses and Dissertations--Statistics

Because of the advances of modern technology, the size of the collected data nowadays is larger and the structure is more complex. To deal with such kinds of data, sufficient dimension reduction (SDR) and reduced rank (RR) regression are two powerful tools. This dissertation focuses on these two tools and it is composed of three projects. In the first project, we introduce a new SDR method through a novel approach of feature filter to recover the central mean subspace exhaustively along with a method to determine the dimension, two variable selection methods, and extensions to multivariate response and large p …

Revisiting Absolute Pose Regression, Hunter Blanton

Theses and Dissertations--Computer Science

Images provide direct evidence for the position and orientation of the camera in space, known as camera pose. Traditionally, the problem of estimating the camera pose requires reference data for determining image correspondence and leveraging geometric relationships between features in the image. Recent advances in deep learning have led to a new class of methods that regress the pose directly from a single image.

This thesis proposes methods for absolute camera pose regression. Absolute pose regression estimates the pose of a camera from a single image as the output of a fixed computation pipeline. These methods have many practical benefits …

2020 Kentucky River Watershed Watch: Annual Report, Malissa Mcalister, Steven Evans

Kentucky River Watershed Watch

No abstract provided.

A Multi-Wavelength Study Of The Disk Winds And Their Role In The Agn Studies, Maryam Dehghanian

Theses and Dissertations--Physics and Astronomy

Active galactic nuclei (AGNs) are located at the centers of massive galaxies and are the most luminous objects in the universe. Each AGN embeds a super-massive black hole which produces outflows of gas, or winds. These winds are important because they provide a reasonable physical basis for the connections between the black hole and the properties of their host galaxy. While AGNs have been extensively studied, several fundamental questions about them are yet to be answered. These include the structure and dynamics of the central source and their winds, and questions regarding the evolution of these galaxies.

NGC 5548 is …

Novel Hedonic Games And Stability Notions, Jacob Schlueter

Theses and Dissertations--Computer Science

We present here work on matching problems, namely hedonic games, also known as coalition formation games. We introduce two classes of hedonic games, Super Altruistic Hedonic Games (SAHGs) and Anchored Team Formation Games (ATFGs), and investigate the computational complexity of finding optimal partitions of agents into coalitions, or finding - or determining the existence of - stable coalition structures. We introduce a new stability notion for hedonic games and examine its relation to core and Nash stability for several classes of hedonic games.

Analyzing The Effect Of Second-Class Currents On Neutron Beta Decay Observables And The Effect Of Thomas Rotation On The Relativistic Transformations Of Electromagnetic Fields, Lakshya Malhotra

Theses and Dissertations--Physics and Astronomy

The next generation of neutron beta decay measurements will attempt to analyze various beta decay observables of up to O(10^-4) precision. At this level of experimental precision, the effects of second-class currents will contribute theoretical uncertainties to the interpretation of these measurements. Therefore, it is important to investigate the effects of these second-class currents on decay parameters, such as the Fierz interference term b which is linear in beyond standard model couplings. A maximum likelihood statistical framework and Rfit techniques are employed to study these second-class currents effects. Inputs to the Rfit technique are obtained through …

Markov Decision Processes With Embedded Agents, Luke Harold Miles

Theses and Dissertations--Computer Science

We present Markov Decision Processes with Embedded Agents (MDPEAs), an extension of multi-agent POMDPs that allow for the modeling of environments that can change the actuators, sensors, and learning function of the agent, e.g., a household robot which could gain and lose hardware from its frame, or a sovereign software agent which could encounter viruses on computers that modify its code. We show several toy problems for which standard reinforcement-learning methods fail to converge, and give an algorithm, `just-copy-it`, which learns some of them. Unlike MDPs, MDPEAs are closed systems and hence their evolution over time can be treated as …

Magnetization Dynamics In Kagome Artificial Spin Ice Considering The Effect Of Vertex And Geometrical Lattice Distortion, Ali Frotanpour

Theses and Dissertations--Physics and Astronomy

Artificial spin ices (ASI) have been shown to exhibit dynamic magnetic responses that are dramatically different from plane magnetic thin films. A number of magnetic ASI have been fabricated and measured in recent years. However, some important effects including influence of vertex and geometrical distortion on their dynamic response have not been addressed. This dissertation adopts Ferromagnetic Resonance (FMR) spectroscopy to study magnetization dynamics in fabricated artificial spin ices with a contentiously distorted Honeycomb geometry with the specific goal of exploring how the vertex and lattice distortion affect the dynamic magnetic response. Samples were patterned using electron beam lithography techniques. …

Topics In Quantum Quench And Entanglement, Sinong Liu

Theses and Dissertations--Physics and Astronomy

The dissertation includes two parts.

In Part I, we study non-equilibrium phenomena in various models associated with global quantum quench. It is known that local quantities, when subjected to global quantum quench across or approaching critical points, exhibit a variety of universal scaling behaviors at various quench rates. To investigate if similar scaling holds for non-local quantities, we consider the scaling behavior of circuit complexity under quantum quench across the critical massless point in Majorana fermion field theory of the one-dimensional integrable transverse field Ising model and find it obeys such scaling. To investigate if similar scaling holds for non-relativistic …

Effective Field Theory Applications: From Dark Matter To Neutrino Nucleon Scattering, Qing Chen

Theses and Dissertations--Physics and Astronomy

Weakly-interacting-massive-particles (WIMPs) are a large class of viable dark matter candidates. We compute cross sections for electroweak-doublet WIMPs scattering on atomic nuclei, at leading and subleading order using heavy WIMP effective field theory. Neutrino-nucleon charged current elastic scattering is an important process in the detectors of long baseline accelerator neutrino oscillation experiments. We compute QED radiative corrections to this process employing soft-collinear effective field theory.

Exploring The X-Ray Universe In The Microcalorimeter Era, Priyanka Chakraborty

Theses and Dissertations--Physics and Astronomy

Next-generation microcalorimeter missions like XRISM and Athena will revolutionize X-ray spectroscopy by offering a plethora of high-resolution X-ray spectra. Interpreting these observations requires a complete understanding of how matter interacts with light through such microphysical processes as absorption and excitation. I developed a framework describing the atomic processes for both collisionally-ionized and photoionized plasmas over a wide range of column densities. Through various line-intensity and line-ratio spectral diagnostics, I established four asymptotic limits; Cases A, B, C, and D. These apply to the formation of lines in H- and He-like systems. This is the first work describing these limits in …

Axial Symmetry Tests Of Milky Way Disk Stars Probe The Galaxy's Matter Distribution, Austin Hinkel

Theses and Dissertations--Physics and Astronomy

In Galactic dynamics, various assumptions have been employed for mathematical ease. These assumptions are approximately valid, but departures reveal perturbations on our Galaxy. In this dissertation, we select a complete, Gaia DR2 data set, and using this data, we find evidence for axial symmetry breaking in the Galaxy, away from the spiral arms and the Galactic bar. This asymmetry is compatible with a prolate dark matter halo tilted with respect to the disk, with a long axis pointing in the direction of the Magellanic Clouds, and this matches an inventory of nearby torques. These asymmetries vary North and South of …