Physical Sciences and Mathematics Commons^™

The Sound Of Geological Targets On Mars From The Absolute Intensity Of Laser-Induced Sparks Shock Waves, C. Alvarez-Llamas, J. Laserna, J. Moros, P. Purohit, L. García-Gómez, S. M. Angel Ph.D., P. Bernardi, B. Bousquet, A. Cadu, E. Dauson, O. Forni, T. Fouchet, O. Gasnault, X. Jacob, G. Lacombe, N. L. Lanza, C. Larmat, J. Lasue, R. D. Lorenz, P. Y. Meslin, D. Mimoun, F. Montmessin, N. Murdoch, A. M. Ollila, P. Pilleri, N. Randazzo, A. L. Reyes-Newell, S. Schröder, A. Stott, J. Ten Cate, A. Udry, D. Vogt

Faculty Publications

Inspection of geological material is one of the main goals of the Perseverance rover during its journey across the landscape of the Jezero crater in Mars. NASA's rover integrates SuperCam, an instrument capable of performing standoff characterization of samples using a variety of techniques. Among those tools, SuperCam can perform laser-induced breakdown spectroscopy (LIBS) studies to elucidate the chemical composition of the targets of interest. Data from optical spectroscopy can be supplemented by simultaneously-produced laser-produced plasma acoustics in order to expand the information acquired from the probed rocks thanks to the SuperCam's microphone (MIC) as it can be synchronized with …

Dissolved Oxygen Dynamics And Nutrient Cycling In Marine And Lacustrine Benthic Communities, Corrianna R. Boucher

Theses and Dissertations

The delivery of biodetritus to the sediment water interface supports a complex series of biogeochemical reactions collectively referred to as early diagenesis. From the abyssal ocean to littoral freshwater ecosystems, this work explores the dynamics of these reactions in deep ocean detrital aggregates and lacustrine benthic algal mats. In the ocean, periods of increased export flux to abyssal depths increase the organic carbon export as aggregates to the seafloor while in littoral freshwater, proliferations of benthic algae such as Microseira wollei have grown to fill much of the shallow water column they inhabit.

Data collected at Station M (Sta. M) …

Approaches To Detecting And Modeling Over-And Underdispersion In Alternative Count Data Distributions And An Application Of Logistic Regression And Random Forest Modeling To Improve Screening Tools For Tic Disorders In Children, Rebecca C. Wardrop

Theses and Dissertations

This dissertation focuses on theory and application of discrete data methods, particularly approaches to over- and underdispersion relative to the Poisson distribution and an application of random forest and logistic regression modeling. The first chapter derives a score test for over- and underdispersion in the heaped generalized Poisson distribution. Equi-, over-, and underdispersed heaped generalized Poisson and heaped negative binomial data are simulated to evaluate the performance of the score test by comparing the power it achieves to that of Wald and likelihood ratio tests. We find that the score test we derive performs comparably to both the Wald and …

Computational Studies Of Bond Dissociation Energies And Organic Reaction Mechanisms, Shehani Thishakkya Wetthasinghe

Theses and Dissertations

This dissertation presents the progress of two independent projects. Chapter 2 and Chapter 3 focus on the first project, which involves material exploration utilizing machine learning techniques. We explore the potential use of cobaltocenium (CoCp⁺₂) derivatives as metal cations in anion exchange membranes (AEMs) for alkaline fuel cells, highlighting their superior thermal and alkaline stability compared to ammonium derivatives. The stability of CoCp⁺₂ can be fine-tuned by varying the substituent groups attached to the cyclopentadienyl ring (Cp) in CoCp⁺₂ .These derivatives encompass a variety of electron-donating and electron-withdrawing groups as substituents on both …

Statistical Methods For Single Cell Sequencing Data Analysis, Fei Qin

Theses and Dissertations

The recent emergence of single cell sequencing (SCS) technology has provided us with single-cell DNA or RNA sequencing (scDNA/RNA-seq) information to investigate cellular evolutionary relationships. Despite many analysis methods have been developed to infer intra-tumor genetic heterogeneity, cluster cellular subclones, detect genetic mutations, and investigate spatially variable (SV) genes, exploring SCS data remains statistically challenging due to its noisy nature.

To identify subclones with scDNA-seq data, many existing studies use an independent statistical model to detect copy number profile in the first step, followed by classical clustering methods for subclone identification in downstream analyses. However, spurious results might be generated …

Deep Learning Methods For Some Problems In Scientific Computing, Yuankai Teng

Theses and Dissertations

Deep learning has emerged as a powerful approach for solving complex problems in scientific computing due to the increasing availability of large-scale data and computational resources. This thesis explores the potential of deep learning methods for three specific problems in scientific computing: (i) reducing the dimensions of variables in function approximation, (ii) solving linear reaction-diffusion equations, and (iii) finding the parametric representations of parameters in the numerical schemes for solving time-dependent partial differential equations.

For the first problem, a novel deep learning architecture is developed for reducing the dimensions of variables in function approximation. The proposed method achieves state-of-the-art performance …

Measurement Of The Total Cross-Section Of Muon Neutrino Charged-Current Coherent Pion Production In Nova Near Detector, Kuruppumullage Don Chatura Dilshan Kuruppu

Theses and Dissertations

Charged Current (CC) coherent neutrino-nucleus pion production is characterized by small momentum transferred to the nucleus, which is left in its ground state. Despite the relatively large uncertainties on the production cross-section, coherent production of mesons by neutrinos represents an important process, as it can shed light on the structure of the weak current and can also constitute a potential source of background for modern neutrino oscillation experiments and searches for Beyond Standard Model (BSM) physics. This Ph.D. thesis presents a new measurement of CC coherent pion production in the NOvA near detector at the Fermi National Accelerator Laboratory (Fermilab). …

Identification Of New Disinfection Byproducts In Drinking Water And Impacts Of Algae, Md. Tareq Aziz

Theses and Dissertations

The disinfection of water has been hailed as one of the most important triumphs for public health in the 20th century. Drinking water treatment plants produce safe drinking water by inactivating microorganisms through the use of disinfectants, including chlorine, chloramine, chlorine dioxide, UV irradiation, and ozone. However, these disinfectants also produce toxic disinfection by-products (DBPs), through reactions with natural organic matter and anthropogenic pollutants, as well as bromide and iodide present in source waters. The presence of bromide and iodide results in the formation of bromo- and iodo-DBPs which are much more toxic than DBPs containing chlorine. DBPs are always …

Extending The Convolution In Graph Neural Networks To Solve Materials Science And Node Classification Problems, Steph-Yves Mike Louis

Theses and Dissertations

The usage of graph to represent one's data in machine learning has grown in popularity in both academia and the industry due to its inherent benefits. With its flexible nature and immediate translation to real life observed objects, graph representation had a considerable contribution in advancing the state-of-the-art performance of machine learning in materials.

In this dissertation proposal, we discuss how machines can learn from graph encoded data and provide excellent results through graph neural networks (GNN). Notably, we focus our adaptation of graph neural networks on three tasks: predicting crystal materials properties, nullifying the negative impact of inferior graph …

Study Of Non-Covalent Interactions Using Molecular Rotors And Balances, Daniel Onyekachi Madukwe

Theses and Dissertations

The main focus of this dissertation is on the quantification of non-covalent interactions using molecular rotors and balances. While molecular rotors were used to measure kinetic effects of weak non-covalent interactions, molecular balances were used to measure their thermodynamic effects. Chapters 1 and 2 focus on the use of molecular rotors in measuring and studying the kinetic effects of the hydrogen bonding interaction on the bond rotation transition states. Chapters 3 and 4 focus on the quantification of lone pair – lone pair and sp²-CH/π interactions respectively, using molecular balances. These studies were carried out in the …

Widely Digitally Delicate Brier Primes And Irreducibility Results For Some Classes Of Polynomials, Thomas David Luckner

Theses and Dissertations

This dissertation considers three different sections of results. In the first part of the dissertation, a result on consecutive primes which are widely digitally delicate and Brier numbers is discussed. Making use of covering systems and a theorem of D. Shiu, M. Filaseta and J. Juillerat showed that for every positive integer k, there exist k consecutive widely digitally delicate primes. They also noted that for every positive integer k, there exist k consecutive primes which are Brier numbers. We show that for every positive integer k, there exist k consecutive primes that are both widely digitally …

Groundwater Flow And Salt Marsh Migration: The Forest/Marsh Boundary, Camille Rossiello

Theses and Dissertations

Salt marshes migrate landward in response to sea level rise, but the rate of this migration is not constant and can be influenced by pulse disturbances. Long term observations at Sapelo Island, Georgia, show that salt marsh migration has occurred during droughts, but the mechanism for this migration is unclear. Drought is thought to influence salt marsh migration by reducing fresh groundwater discharge from the upland. Rising sea level also encroaches on the upland, which could cause movement of the freshwater lens inland. A two-dimensional numerical model was built to simulate groundwater flow and solute transport based on the Marsh …

Expanding On The Solid State Chemistry Of F-Element Chalcogenides, Logan Skyler Breton

Theses and Dissertations

An overarching goal in solid state chemistry is to achieve predictability regarding the synthesis of compounds with desired properties. While this goal is far from being reached, solid state chemists are hard at work synthesizing and characterizing new materials to further our understanding of structure-property relationships, and to expand our fundamental knowledge to rationalize the outcomes of solid-state syntheses. With the advent of new solid state synthetic methods, novel compounds exhibiting exciting properties are still being discovered today. The infancy of these synthetic methods promises a myriad of undiscovered compounds with potentially interesting properties which has resulted in a recent …

A Bayesian Spatial Scan Statistic For Normal Data, Laasya Velamakanni

Theses and Dissertations

Scan statistics are useful methods for detecting spatial clustering. While they were initially developed to detect regions with an excess of binomial or Poisson events, spatial scan statistics have been extended to detect hotspots in other types of data including continuous data. They have many applications in different fields such as epidemiology (e.g. detecting disease outbreaks), sociology (e.g. detecting crime hotspots), and environmental health (e.g. detecting high-pollution areas). Spatial scan statistics identify a ‘most likely cluster’ and then use a likelihood ratio test to determine if this cluster is statistically significant. Spatial scan statistics have been extended to the Bayesian …

Predicting Material Structures And Properties Using Deep Learning And Machine Learning Algorithms, Yuqi Song

Theses and Dissertations

Discovering new materials and understanding their crystal structures and chemical properties are critical tasks in the material sciences. Although computational methodologies such as Density Functional Theory (DFT), provide a convenient means for calculating certain properties of materials or predicting crystal structures when combined with search algorithms, DFT is computationally too demanding for structure prediction and property calculation for most material families, especially for those materials with a large number of atoms. This dissertation aims to address this limitation by developing novel deep learning and machine learning algorithms for effective prediction of material crystal structures and properties. Our data-driven machine learning …

Machine-Learning Classification To Predict The Dimensionality Of Hybrid Organic-Inorganic Halide Perovskites, Yatiwelle Koralalage Samuditha Sandaru Yatiwella

Theses and Dissertations

Low dimensional hybrid perovskites have demonstrated remarkable performance in photovoltaic applications, primarily due to their exceptional optical and electronic properties. As the search for potential candidates for novel materials continues, understanding the structure of these materials is crucial for investigating their stability. In this study, we implement a framework to find novel material based on a machine-learning model. The machine learning model was trained to predict the dimensionality of the polyhedral network based on the connectivity of the polyhedral network in different directions. The polyhedral connectivity of low-dimensional structures can be classified into three dimensions: 0D, 1D, and 2D. This …

Yield Extraction For The Γd → Λ X Reaction, K H P Nishadi Hasarangi Silva

Theses and Dissertations

Improving and adding new experimental measurements of hyperon-nucleon (YN) and hyperon-deuteron (Yd) cross sections is an active area in nuclear physics research. Scientists use such cross-section data to understand the composition of neutron stars and develop a comprehensive picture of the baryon-baryon interaction. Using high luminosity photon beam incident on a long liquid deuterium target and the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab), a sample of hyperon-deuteron elastic scattering events was previously identified. The E06-103 (g13) experiment was originally designed to address the scarcity of experimental data on hyperon photoproduction off the neutron …

Nitrous Oxide Cycling In The Eastern Tropical North Pacific Oxygen Deficient Zone From Concentrations, Stable Isotopes And Isotopomers, Margaret Ann Gaspar

Theses and Dissertations

Nitrous oxide (N₂O) is a potent greenhouse gas and ozone depleting substance. It is estimated that the ocean accounts for about one third of total atmospheric emissions, which mostly occur in Oxygen Deficient Zones (ODZs) connected to coastal upwelling regions. Modeling efforts and high-resolution datasets are starting to provide a clearer picture of global marine N₂O fluxes, spatiotemporal variability, and the impacts of submesoscale processes on N₂O distributions. We measured nitrous oxide concentrations, stable isotope ratios and isotopomers at 7 open ocean stations along a transect crossing the Eastern Tropical North Pacific ODZ as …

Marine Anoxia Initiates Giant Sulfur-Bacteria Mat Proliferation And Associated Changes In Benthic Nitrogen, Sulfur, And Iron Cycling In The Santa Barbara Basin, California Borderland, David J. Yousavich, De'marcus Robinson, Xuefeng Peng, Sebastian J.E. Krause, Frank Wenzhoefer, Felix Janßen, Na Liu, Jonathan Tarn, Frank Kinnaman, David L. Valentine, Tina Treude

Faculty Publications

The Santa Barbara Basin naturally experiences transient deoxygenation due to its unique geological setting in the southern California Borderland and seasonal changes in ocean currents. Long-term measurements of the basin showed that anoxic events and subsequent nitrate exhaustion in the bottom waters have been occurring more frequently and lasting longer over the past decade. One characteristic of the Santa Barbara Basin is the seasonal development of extensive mats of benthic nitrate-reducing sulfur-oxidizing bacteria, which are found at the sediment–water interface when the basin's bottom waters reach anoxia but still provide some nitrate. To assess the mat's impact on the benthic …

Perturbative Aspects Of Cpt-Even Lorentz-Violating Scalar Chromodynamics, Brett Altschul, L. C.T. Brito, J. C.C. Felipe, S. Karki, A. C. Lehum, A. Yu Petrov

Faculty Publications

In this work, we formulate the theory of Lorentz-violating scalar quantum chromodynamics with an arbitrary non-Abelian gauge group. This theory belongs to the class of models encompassed by the standard model extension framework. At the lowest order in the theory's Lorentz violation parameters, we calculate the divergent quantum corrections, including the renormalization group β-functions of the theory. The Lorentz-violating sector is shown to be scale invariant if there is a particular relation between the couplings.

Ten‐Year Cardiovascular Disease Risk Score And Cognitive Function Among Older Adults: The National Health And Nutrition Examination Survey 2011 To 2014, Jingkai Wei, Hanzhang Xu, Angela D. Liese, Anwar T. Nerchant Sc.D, Mph, Dmd, Liang Wang, Chih-Hsiang Yang, Matthew C. Lohman, Monique J. Brown Ph.D., Mph, Tiansheng Wang, Daniela B. Friedman Ph.D.

Faculty Publications

BACKGROUND: The Framingham 10-year cardiovascular disease risk score, which is based on age, sex, smoking, total cholesterol, high-density lipoprotein-cholesterol, blood pressure, and diabetes, has been found to be associated with cognitive health, but these findings have not been validated in a representative sample in the United States. We aimed to examine the associations of Framingham risk score with cognitive function among older adults in a nationally representative sample, as well as by race or ethnicity, education, and family income.

METHODS AND RESULTS: A total of 2254 older adults ≥60years (57% female, 79% non-Hispanic White) in the National Health and Nutrition …

Patterns Of Hiv Disclosure And Its Impact On The Hiv Care Continuum Among Black Men Who Have Sex With Men In South Carolina, Xueying Yang Ph.D., Titilayo A. James, Monique J. Brown Ph.D., Mph, Tony Brown, Sydney Zarsadias, Ran Zhang, Fanghui Shi, Xiaoming Li Ph.D.

Faculty Publications

Addressing the psychosocial concerns of Black men who have sex with men (MSM), such as HIV disclosure, is critical for effective HIV treatment efforts. Black MSM living with HIV experience multiple psychosocial challenges, such as “triple stigma” due to their sexual orientation, racial minority status, and HIV status, which hinder their HIV disclosure and subsequent HIV care-seeking behavior. Our study sought to examine the HIV disclosure patterns and their impact on the HIV care continuum among Black MSM using a qualitative approach. Semi-structured interviews were carried out among 28 Black MSM aged ≥18 years old living in South Carolina. A …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Trends In Resources For Neonatal Intensive Care At Delivery Hospitals For Infants Born Younger Than 30 Weeks' Gestation, 2009-2020, Nansi S. Boghossian, Marco Geraci, Ciaran S. Phibbs, Scott A. Lorch, Erika M. Edwards, Jeffrey D. Horbar

Faculty Publications

Importance: In an ideal regionalized system, all infants born very preterm would be delivered at a large tertiary hospital capable of providing all necessary care. Objective: To examine whether the distribution of extremely preterm births changed between 2009 and 2020 based on neonatal intensive care resources at the delivery hospital. Design, Setting, and Participants: This retrospective cohort study was conducted at 822 Vermont Oxford Network (VON) centers in the US between 2009 and 2020. Participants included infants born at 22 to 29 weeks' gestation, delivered at or transferred to centers participating in the VON. Data were analyzed from February to …

Search For B Mesogenesis At Babar, J. P. Lees, V. Poireau, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu. G. Kolomensky, M. Fritsch, H. Koch, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, E. A. Kozyrev, Milind Purohit, Et. Al.

Faculty Publications

A new mechanism has been proposed to simultaneously explain the presence of dark matter and the matter-antimatter asymmetry in the Universe. This scenario predicts exotic B-meson decays into a baryon and a dark-sector antibaryon (ψD) with branching fractions accessible at B factories. We present a search for B→Λψ_D decays using data collected by the BABAR experiment at SLAC. This reaction is identified by fully reconstructing the accompanying B meson and requiring the presence of a single Λ baryon in the remaining particles. No significant signal is observed, and bounds on the B→Λψ …

Consumers And Eco-Labels: A Quantitative Analysis Of The Effects Of Various Sustainability Certification Models On Consumer Opinions, William F. Joseph

Senior Theses

This research consists of an econometric analysis of the efficacy of a privatized sustainability certification model versus a proposed government-endorsed sustainability certification model within the United Sates market. Today, the widely accepted model of sustainability certification is constituted by a large market of private certifiers. By analyzing the effects of the current model and alongside the effects of a hypothetical government-endorsed system on consumer preferences for sustainably produced goods, the thesis aims to motivate further discussion into the possible benefit of adopting a government-sponsored sustainability certification system. In general, analysis of the data suggests much more promising and significant effects …

Modeling The Probability Of A Successful Stolen Base Attempt In Major League Baseball, Cade Stanley

Senior Theses

In Major League Baseball (MLB), the outcome of a stolen base attempt has important implications. Success moves the runner closer to scoring, while failure records an out and removes the runner from the basepaths altogether. Therefore, it is important that the decision by a coach or player to steal a base is well-informed. In this thesis, I explore a statistical approach to making this decision. I train logistic regression and random forest models, using data about the game situation and about the runner, pitcher, and catcher involved in the stolen base attempt, to estimate the probability that a stolen base …

Structure Of Extremal Unit Distance Graphs, Kaylee Weatherspoon

Senior Theses

This thesis begins with a selective overview of problems in geometric graph theory, a rapidly evolving subfield of discrete mathematics. We then narrow our focus to the study of unit-distance graphs, Euclidean coloring problems, rigidity theory and the interplay among these topics. After expounding on the limitations we face when attempting to characterize finite, separable edge-maximal unit-distance graphs, we engage an interesting Diophantine problem arising in this endeavor. Finally, we present a novel subclass of finite, separable edge-maximal unit distance graphs obtained as part of the author's undergraduate research experience.

Muon Intensity Measurement With The Majorana Demonstrator, Franklin Michael Adams Jr.

Theses and Dissertations

The Majorana Demonstrator (MJD) is a shielded radiation detection system located a mile underground at the Sanford Underground Research Facility (SURF) in South Dakota. The system aims to detect the theorized, rare process of neutrinoless double-beta decay. The Demonstrator utilizes an array of scintillating acrylic detectors to veto any signals induced by earth-penetrating cosmogenic muons and reach background levels necessary for the detection of neutrinoless double-beta decay. Utilizing the data collected by the muon veto system, an analysis has been done to determine the differential muon intensity. The complex geometry of the interlacing detector panels requires the use of Monte …

Templates To Transition: Making Solar-Generated Electricity Accessible For Lagos Residents, Adeola O. Adebajo

Senior Theses

According to the EPA, direct energy production results in at least 25% of the world’s emissions. This refers to emissions produced by burning coal, natural gas, and oil for electricity and heat. With the increasing effects of climate change, sustainable energy is becoming increasingly important as the world shifts away from fossil fuels. However, implementation of renewable energy sources is not as fast or as widespread as necessary. This paper aims to identify feasible solutions to the problem of renewable energy affordability in Nigeria especially in growing megacities like Lagos to ensure long lasting and climatefriendly energy sources. Two major …