Physical Sciences and Mathematics Commons^™

Dataset Of Optical And Electronic Properties For Mos2-Graphene Vertical Heterostructures And Mos2-Graphene-Au Heterointerfaces, Sanju Gupta, Panagiota Pimenidou, Miguel Garcia, Shivanshi Das, Nicholas Dimakis

Physics & Astronomy Faculty Publications

The computational and experimental data presented in this paper refer to the research article "First-Principles Calculations Integrated with Experimental Optical and Electronic Properties for MoS2-graphene Heterostructures and MoS2-graphene-Au Heterointerfaces". The computational data includes structural information, electronic and optical properties, and data to calculate the work functions for various molybdenum disulfide and graphene heterostructures and their heterointerfaces with gold. The optical properties calculations include the frequency-dependent dielectric function, the refractive index, the reflectivity, the extinction coefficient, and the energy loss function. These properties were calculated using the independent particle approximation (IPA). As for the experimental optoelectronic properties, we measured photoluminescence spectra …

The Development Of Artificial Intelligence-Based To Ols For Expert Peer Review Of Radiotherapy Treatment Plans, Mary Gronberg

Dissertations and Theses (Open Access)

Creating a patient-specific radiation treatment plan is a time-consuming and operator-dependent manual process. The treatment planner adjusts the planning parameters in a trial-and-error fashion in an effort to balance the competing clinical objectives of tumor coverage and normal tissue sparing. Often, a plan is selected because it meets basic organ at risk dose thresholds for severe toxicity; however, it is evident that a plan with a decreased risk of normal tissue complication probability could be achieved. This discrepancy between “acceptable” and “best possible” plan is magnified if either the physician or treatment planner lacks focal expertise in the disease site. …

Statistical Modeling Approaches For The Inference Of Cancer Mechanisms, Licai Huang

Dissertations and Theses (Open Access)

The aim of this study was to explore the potential of integrating multi-platform genomic datasets to improve our understanding of the biological mechanisms behind cancer. By merging clinical outcomes with the data obtained from multi-platform genomic studies, we can gain insight into the biological mechanisms behind a patient’s response to treatment. Additionally, the evaluation of the correlations between genetic variations and gene expression provides a better understanding of the functional significance of these variations. Such knowledge has the potential to revolutionize cancer diagnosis and treatment. This thesis describes methods developed to address two related aims. Aim 1: We have developed …

Statistical Approaches To Estimate Bidirectional And Time-Varying Causal Effects Using Mendelian Randomization, Jinhao Zou

Dissertations and Theses (Open Access)

Mendelian Randomization (MR) is an epidemiological framework using genetic variants as instrumental variables (IVs) to examine the causal effect of an exposure on an outcome. It is widely used to detect causal factors of diseases and provide insight into the biological pathway of diseases. Current methods under the MR framework are built to estimate the unidirectional causal effects of exposures on outcomes and neglect the potential bidirectional causal effects. However, a bidirectional causal effect creates a feedback loop that biases the casual inference in MR studies. Furthermore, current MR methods estimate the causal effect as a single value using cross-sectional …

Uncertainty In The Physical Basis Of Estimates Of Relative Biological Effectiveness In Carbon Radiotherapy, Shannon Hartzell, Shannon Hartzell Ph.D.

Dissertations and Theses (Open Access)

Carbon ion radiotherapy is a novel modality used for the treatment of tumors that are unresectable, close to critical structures, or resistant to standard radiotherapy. A unique benefit of this therapy is the relative biological effectiveness (RBE) of the beam (i.e., how biologically potent carbon ions are as compared to x-rays), which is significantly elevated. This RBE also varies as a function of many parameters, and there are currently several models implemented in clinical and research-based treatment planning systems with which to predict RBE. These algorithms are computationally expensive and there are currently no means of validating their implementation within …

Composite And Polymer Formulation Employing Sulfur And Bio-Olefin Feedstocks, Claudia V. Lopez

All Dissertations

Environmental sustainability represents a challenge for society since industrial growth has a direct impact on natural resources and waste production. New technologies that effectively incorporate waste into renewable resources are critical to the development of a sustainable and circular economy. The manufacturing of structural materials like Portland cement (OPC) is responsible for >8% of the global anthropogenic emissions of carbon dioxide, with ~ 1 kg of CO₂ released to the atmosphere for every kilogram of OPC produced. For instance, the development of sustainable structural materials is a key factor to reduce the greenhouse emissions and to attenuate the climate …

Social And Economic Changes In A Mid-Size University City: The Case Of South Fayetteville, Arkansas, Korab Vranovci

Graduate Theses and Dissertations

The constant growth of the city of Fayetteville is attributed to regional economic growth and an increase in student enrollment, to name a few. As a middle-sized college city, Fayetteville is an anchor city with the University of Arkansas as its anchor institution. These changes have caused a significant increase in the city's urban development and neighborhood changes. This research identifies three areas of work with the potential to assist in the study of the urban redevelopment in the South Fayetteville neighborhoods: (1) the social demographics, economic, and land use changes in neighborhood populations, (2) the stakeholder's perceptions toward city …

Ber Analysis Of Bpsk Modulation Scheme For Multiple Combining Schemes Over Flat Fading Channel, Zuhaib Nishtar, Jamil Afzal

Neutrosophic Systems with Applications

Focus of the study was to provide error-free communication in mobile communication with higher data rates, spectral efficiency, and energy efficient. Basically, work was done to investigate the performance of the Binary Phase Shift Keying (BPSK) modulation technique for multiple combining schemes and the behavior of signal in wireless communication where multipath propagation and uncertainty in the system. We use the Multiple-input Multiple-output (MIMO) and antenna diversity to get many copies of the same signal; some of them were faded, but some had sufficient information. Then the next step was to combine or select the best signal to achieve the …

Generalized Double Statistical Convergence Sequences On Ideals In Neutrosophic Normed Spaces, Jeyaraman M., Iswariya S., Pandiselvi R.

Neutrosophic Systems with Applications

In this present research, having view in the Neutrosophic norm (u, v, w), which we presented I2-lacunary statistical convergence and I2-lacunary convergence strongly, looked into interactions between them, and made a few findings regarding the respective categories. At least went further to look at how both of such case approaches relate to I2-statistical convergence within the relevant Neutrosophic normed space.

Addressing Health Crises Through Courts? Climate Litigation In Latin America, The Right To Health And Vulnerable Populations, Thalia Viveros Uehara

Graduate Doctoral Dissertations

As Latin America faces increasing climate-related health crises that disproportionately affect populations experiencing poverty and social exclusion, it becomes increasingly urgent to realize the most vulnerable's right to health. While the region's new constitutionalism (NLAC) has made progress in protecting this right, it has only recently begun to intersect with climate change law through rights-based climate litigation. This dissertation takes a transdisciplinary multi-methods research approach to answer the following question: How do health crises emerge within, and how are they addressed by courts through, domestic climate litigation in Latin America? Specifically, it examines how health concerns for vulnerable populations are …

Application Of Business Analytics Approaches To Address Climate-Change-Related Challenges, Donald J. Jenkins

Graduate Doctoral Dissertations

Climate change is an existential threat facing humanity, civilization, and the natural world. It poses many multi-layered challenges that call for enhanced data-driven decision support methods to help inform society of ways to address the deep uncertainty and incomplete knowledge on climate change issues. This research primarily aims to apply management, decision, information, and data science theories and techniques to propose, build, and evaluate novel data-driven methodologies to improve understanding of climate-change-related challenges. Given that we pursue this work in the College of Management, each essay applies one or more of the three distinct business analytics approaches (i.e., descriptive, prescriptive, …

Organocatalyzed Four-Component On-Water Green Synthesis Of Spiroindolinpyranopyrazole, Tanzida Zubair

Theses and Dissertations

Although many synthetic and natural pharmaceuticals and drug-like compounds contain spiro center(s) in their structures, the synthesis of spiro centers is seen to be an exciting and difficult area of research. The synthesis of spiro compounds and their derivatives was carried out using a four-component process that included reagents like hydrazine hydrate, isatin, malononitrile, and an active methylene compound like ethyl acetoacetate. Microwave irradiation was used in a short time range (5 – 30 min) and moderate temperature (80°C), with water as a solvent, and N, N-Diisopropylethylamine (DIPEA) as a catalyst to give high yield of products. Our process complies …

Design Of Topological Structures With Desired-Shape Mid-Gap State, Elnaz Hamdarsi

Theses and Dissertations

Topological systems with their robust features are of interest in different fields including electronics, acoustics, and photonics. Systems with non-trivial topological configurations are the host of the so-called edge modes with energy eigenfrequency lying at the center of the gap and are protected by the symmetries of the structure. The eigenstates associated with these mid-gap modes are exponentially localized at the boundaries. For practical applications, it is of great interest to design systems that have a protected state not necessarily squeezed towards the edges, and in some cases, it is crucial to have it as a distributed state. Here, using …

A Hybrid Lateral Flow Sand Filter Wastewater Treatment System: An Evaluation On The Treatment And Disposal Capabilities Of A Modified Sand Filter, Harry Mccaskill Iv

Graduate Theses and Dissertations (2019 - present)

Decentralized wastewater treatment exists primarily in suburban and rural areas where centralized treatment is not an option. Traditional on-site treatment systems usually include the use of a septic tank and a drain field. This orthodox method works well when implemented into environments that are accommodating for the infiltration of effluents, and thus allowing for soil treatment. Unfortunately, there are some circumstances that prevent traditional systems from working such as impermeable soil conditions. The Wastewater Treatment System analyzed in this thesis was created to overcome such inhospitable environments. More specifically, this system is catered towards the rural residences of The Alabama …

Epileptic Seizure Classification Using Image-Based Data Representation, Amber Surles

Graduate Theses and Dissertations (2019 - present)

Epilepsy is a recurrence of seizures caused by a disorder of the brain in over 3.4 million people nationwide. Some people are able to predict their seizures based off prodrome, which is an early sign or symptom that usually resembles mood changes or a euphoric feeling even days to an hour before occurrence. Consequently, the natural instincts of the body to react to an upcoming attack lends credence to the existence of a pre-ictal state that precedes seizure episodes. Physicians and researchers have thus sought for an automated approach for predicting or detecting seizures.

In this research, we evaluate the …

Algorithms For Computing Invariants Of Trisected Branched Covers, Patricia Cahn, Gordana Matic, Benjamin Ruppik

Mathematics Sciences: Faculty Publications

We give diagrammatic algorithms for computing the group trisection, homology groups, and intersection form of a closed, orientable, smooth 4-manifold, presented as a branched cover of a bridge-trisected surface in ��4. The algorithm takes as input a tri-plane diagram, labelled with permutations according to the Wirtinger relations. We apply our algorithm to several examples, including dihedral and cyclic covers of spun knots, cyclic covers of Suciu's ribbon knots with the trefoil knot group, and an infinite family of irregular covers of the Stevedore disk double. As an application, we give a fully automated algorithm for computing Kjuchukova's homotopy-ribbon obstruction for …

Delving Deep: A Population Of Extremely Dusty Dwarfs Observed By Jwst, L. Bisigello, G. Gandolfi, A. Grazian, G. Rodighiero, L. Costantin, A. R. Cooray, A. Feltre, C. Gruppioni, N. P. Hathi, Benne W. Holwerda, A. M. Koekemoer, R. A. Lucas, J. A. Newman, P. G. Pérez-González, L. Y. A. Yung, A. De La Vega, P. Arrabal Haro, M. B. Bagley, M. Dickinson, S. L. Finkelstein, J. S. Kartaltepe, C. Papovich, N. Pirzkal, S. Wilkins

Faculty and Staff Scholarship

Aims. We take advantage of the NIRCam photometric observations available as part of the Cosmic Evolution Early Release Science survey (CEERS) to identify and analyse very red sources in an effort to discover very dusty star forming galaxies. Methods. We select red galaxies as objects with a S / N > 3 at 4.4 μm and a S / N < 2 in all JWST and HST filters at λ ≤ 2 μm, which corresponds to [ F 200 W ]−[ F 444 W ]> 1.2 considering CEERS depths. This selection is ideal to identify very dusty ( A V > 1 mag) galaxies with stellar masses between 10 6 and 10 10 M ⊙ at z < 5, more massive dusty galaxies at z = 5 − 18 and galaxies at z > 18 due to the Lyman absorption, independently of their dust …

Electrochemical Approaches To Life-Support Resources In Space Missions And Nuclear Technologies: Hydrogen Peroxide And Uranium Films, Armando Manuel Pena-Duarte

Open Access Theses & Dissertations

Space race has developed several technological advances that have achieved and continue to achieve the success of space missions in the aerospace timeline. Currently, the number of space technical and scientific innovations is still growing––demanding new materials and developments for extreme performing applications of fuel cells, batteries, supercapacitors, and systems of nuclear energy. Space missions require life-support solutions, auto-sustainable closed-loop living environments, cleaning and sanitizing solutions against pathogens, and safe nuclear-based resources of energy––with fissile materials with well-controlled dimensions within the core fuel elements. Likewise, to guarantee safety conditions, reduce costs, and facilitate operational logistics, space missions must reduce their …

Density Functional Theory Study Of Dopant Incorporation Into Gamma-Uo3, Nicholas James Wilson

Open Access Theses & Dissertations

Uranium trioxide (UO3) is a stable uranium oxide found throughout the nuclear fuel cycle. The γ-UO3 phase is of particular interest as the most stable at ambient conditions. As such, the γ-UO3 structure was selected for a theoretical investigation into the incorporation of metal dopants for nuclear intentional forensics applications. The two lattice types of this phase, tetragonal (I41/amd) and orthorhombic (Fddd), were investigated and found to be energetically identical, and as such the smaller tetragonal structure was selected for doping. Three transition metal dopants (Cr, Fe, and Ni) were incorporated into the structure interstitially and substitutionally at a total …

Removal Of Nonylphenols From Water And Wastewater Using Alginate-Activated Carbon Beads, Angelica Araly Chacon

Open Access Theses & Dissertations

The presence of contaminants of emerging concern (CECs) have been affecting water quality in recent years. The United States Environmental Protection Agency (U.S EPA) defines CECs as toxic chemicals without regulatory status and with adversely impact on the wildlife and people. Among the CECs, nonylphenols (NPs) are frequently found in all water systems and are categorized as endocrine-disrupting compounds (EDCs) due to their ability to mimic hormones causing reproductive and developmental effects in humans and animals. The main sources of discharge and distribution of NPs into the environment are wastewater treatment plants (WWTPs) which are not designed to remove them. …

Using Stable Water Isotopes And Radiogenic Strontium Isotopes To Trace Water And Its Salinity Sources In Pecos And Colorado River Basins In Texas, Nuria Valeria Andreu Garcia

Open Access Theses & Dissertations

Water stable isotope ratios (Deuterium/hydrogen 2H/1H and Oxygen 18O/16O ratios) and radiogenic strontium isotope ratios (87Sr/86Sr) have been widely used to trace various hydrologic processes and understand surface-groundwater interactions for watershed and critical zone studies. Our project aimed to trace the water and salinity sources in the Colorado and Pecos Rivers, two major rivers that provide essential water resources for water-stressed parts of Texas. In our study, we collected water samples from 25 locations during July (monsoon season), December 2021 (dry season), and May 2022 (pre-monsoon season) along the Pecos and Colorado rivers from central Texas to the Gulf of …

Single-Index Multinomial Model For Analyzing Crime Data, Kwabena Gyamfi Duodu

Open Access Theses & Dissertations

We develop a flexible single-index multinomial model for analyzing crime data. In additionto the number of crimes reported, the data also includes covariates such as location, time of day, weather, and other demographic factors. We provide an estimation algorithm and develop R code for the single-index multinomial model. Using simulations, we evaluate the performance of the proposed estimation algorithm. When applied to crime data, the single-index multinomial model provides important insights into crime trends and risk variables, assisting in the development of tailored crime prevention programs. Policymakers and law enforcement organizations can use the model's projections to more efficiently allocate …

Quantifying The Contribution Of Atmospheric And Land Surface Characteristics To The Prediction Of Sub-Pixel Scale Surface Soil Moisture In The Jornada Experimental Range Through Interpretable Machine Learning, Stephanie Nicole Marquez

Open Access Theses & Dissertations

This study presents machine learning-based approaches for understanding and predicting plot-scale soil moisture's spatial variability using hydrometeorological and biogeophysical data from in-situ, multi-sensor and remote sensing sources. The high-resolution input features include numerical and categorical data such as land surface temperature, ground albedo, 1-day, 1-week and 2-week antecedent precipitation, soil type, land cover type, distance to nearest vegetation individual, terrain slope and elevation, and normalized differenced vegetation index (NDVI). Soil moisture measurements are collected within a 3 km x 3 km desert grid with Campbell Scientific Hydrosense II-12 soil moisture sensors and validated with a gravimetric method of measuring volumetric …

Comparative Study Of Supervised Classification Techniques With A Modified Knn Algorithm, Noah Owusu

Open Access Theses & Dissertations

The goal of classification is to develop a model that can be used to accurately assign new observations to labeled classes based on the patterns learned from the training data. K-nearest Neighbors algorithm (KNN) is a popular and widely used algorithm for classification, however, its performance can be adversely affected by the presence of outliers in a dataset. In this study we have modified this existing KNN algorithm that can alleviate the effect of outliers in a dataset, thereby improving the performance of the KNN algorithm. We compared the performances of the Modified KNN method and the Existing KNN algorithm …

Paradox Diapir Inclusions As A Window Into Diapiric Processes In Proximity To The Uncompahgre Uplift And The Early History Of The Paradox Basin, Utah And Colorado, Madison Clare Woelfel

Open Access Theses & Dissertations

Layered evaporite sequences, cyclic, kilometer-thick deposits of salt, are among the most unusual and fascinating lithologies that geologists encounter. There is no recent analogue to their formation, and their ability to flow when subject to differential pressure makes them unique. Salt structures serve as sources for halite, bittern salts, metals, and hydrocarbons and can be used for storage of materials, including hydrocarbons, carbon dioxide, hydrogen, and nuclear waste. Basins in which layered evaporite sequences are deposited receive detrital input sporadically from adjacent areas, depositing inclusions of non-evaporite lithologies that are entrained when salt flows. These inclusions are exposed in a …

Poly(Ionic Liquid)S For Magnetic, Ionic, And Electrical Stimuli-Responsive Applications, Kayla Ann Foley

Graduate Theses and Dissertations

Poly(ionic liquid)s (PILs) are a fascinating subclass of strong polyelectrolytes formed from polymerizable ionic liquids. As a result of their unique properties and counterion exchangeability, PILs can exhibit conformation structure or material property changes in response to external stimuli such as changes in pH/ionic environment, magnetic fields, and electric potentials. In Chapter 1, a comprehensive review of PILs design as well as their stimuli-responsive behavior is provided. Additional motivation for each dissertation chapter is also discussed. In Chapter 2, magnetically responsive PILs (MPILs) are developed from complexing paramagnetic salts with a random PIL copolymer containing a metal-coordinating co-monomer, acrylamide. A …

The Seoul National University Agn Monitoring Project. Iv. Hα Reverberation Mapping Of Six Agns And The Hα Size–Luminosity Relation, Hojin Cho, Jong-Hak Woo, Shu Wang, Donghoon Son, Jaejin Shin, Suvendu Rakshit, Aaron J. Barth, Vardha N. Bennert, Elena Gallo, Edmund Hodges-Kluck, Tommaso Treu, Hyun-Ji Bae, Wanjin Cho, Adi Foord, Jaehyuk Geum, Yashashree Jadhav, Yiseul Jeon, Kyle M. Kabasares, Daeun Kang, Wonseok Kang, Changseok Kim, Donghwa Kim, Minjin Kim, Taewoo Kim, Huynh Anh N. Lee, Matthew A. Malkan, Amit Kumar Mandal, Daeseong Park, Hyun-Il Sung, Vivian U, Peter R. Williams

Physics

The broad-line region (BLR) size–luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ BLR is often estimated from the optical continuum luminosity at 5100 Å, while the size of the Hα BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project, which provides 6 yr photometric and spectroscopic monitoring data, we present our measurements of the Hα lags of high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, …

Flow Dynamics In Cardiovascular Devices: A Comprehensive Review, Venant Niyonkuru, Bosco Jean Ndayishimiye Dr, Anicet Barthélemy Sibomana

Digital Journal of Clinical Medicine

This review explores flow dynamics in cardiovascular devices, focusing on fundamental fluid mechanics principles and normal blood flow patterns. It discusses the role of different structures in maintaining flow dynamics and the importance of stents, heart valves, artificial hearts, and ventricular assist devices in cardiovascular interventions. The review emphasizes the need for optimized designs and further research to enhance knowledge of flow dynamics in cardiovascular devices, advancing the field and improving patient care in cardiovascular interventions.

Intra-Gendered Perceptions And Adoption Of Climate-Smart Agriculture: Evidence From Smallholder Farmers In The Upper East Region Of Ghana, Kwabena Antwi, Philip Antwi-Agyei

Student Publications [Scholarly]

Climate-smart agriculture (CSA) remains a key strategy for sustaining agricultural systems and achieving food security and nutrition. Despite this, uncertainty remains on how intra-gendered dynamics influence its adoption in dryland farming systems. This study implements both quantitative and qualitative approaches including household surveys, key informant interviews, and focus group discussions to explore how intra-gender dynamics shape the perceptions and adoption of climate-smart agriculture in three selected communities (Katanga, Dakio, and Zonno) in the Bolgatanga East District of the Upper East Region of Ghana. Specifically, the study answers the following research questions: (i) What is the degree of change in rainfall …

The Effect Of Energy Consumption, Income, And Population Growth On Co2 Emissions: Evidence From Nardl And Machine Learning Models, Mansoor Ahmed, Wen Huan, Nafees Ali, Ahsan Shafi, Muhsan Ehsan, Kamal Abdelrahman, Saiq Shakeel Abbasi, Anser Ali Khan, Mohammed S. Fnais

Student Publications [Scholarly]

With population and income growth, the need for energy has increased in developing and emerging economies, which has inevitably led to an increase in carbon dioxide emissions (CO₂e). This paper investigates the impact of energy consumption on CO₂e influenced by population growth, energy consumption per capita, and income. In particular, this paper investigates whether or not an increase in energy consumption, energy intensity, energy consumption per capita, population growth, and income impacts CO₂e in China, India, and the USA. The study applied the non-linear Autoregressive distributed lag (NARDL) and machine learning techniques. We found …