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Articles 241 - 270 of 2036

Full-Text Articles in Physical Sciences and Mathematics

Special Education: Inclusion And Exclusion In The K-12 U.S. Educational System, Erik Brault May 2023

Special Education: Inclusion And Exclusion In The K-12 U.S. Educational System, Erik Brault

Dissertations

The U.S. Department of Education defines students with disabilities as those having a physical or mental impairment that substantially limits one or more life activities. Previous research has found that students with disabilities placed in inclusive environments perform better academically and socially compared to students with disabilities who are placed in segregated environments. Yet, we know that inclusion in K-12 general education classrooms across the country is not consistently implemented.

The purpose of this study was to better understand the effects, if any, of general education high school teachers’ personal and professional experiences and knowledge on their attitudes toward educating …


Connecting Social And Ecological Systems In Small-Scale Fisheries In The Philippines, Sara Eisler Marriott May 2023

Connecting Social And Ecological Systems In Small-Scale Fisheries In The Philippines, Sara Eisler Marriott

Dissertations

Nearly 50% of all marine fish capture in the Philippines is from artisanal fisheries, most of which is un- or under-reported. As in many emerging nations around the world, the Philippines cannot fully address overfishing by managing only half of the catch that comes from commercial fisheries. Marine reserves are a popular governance strategy for conservation and of growing interest for fisheries management. Many marine reserves in the Philippines, however, are not considered effective. In 2014, Rare, an international NGO, implemented a community-based management program to increase the effectiveness of the marine reserves, and while it found biomass increased, there …


Origin And Structure Of The First Sharp Diffraction Peak Of Amorphous Solids, Devilal Dahal May 2023

Origin And Structure Of The First Sharp Diffraction Peak Of Amorphous Solids, Devilal Dahal

Dissertations

Several explanations have been reported in the literature about the origin of extended-range oscillations (EROs) in the atomic pair-correlation function of amorphous materials. Although the radial ordering beyond the short-range order of about 5 Å has been extensively studied in amorphous materials, the exact nature of the radial ordering beyond a nanometer is still not resolved. This dissertation address this problem and explains the nature of the EROs by using high-quality models of amorphous silicon (a-Si) obtained from Monte Carlo and Molecular Dynamics simulations. The extended-range ordering in a-Si is examined through radial oscillations on the length …


Spectral Multistep Methods For The Scalable Simulation Of Time-Dependent Phenomena, Bailey Rester May 2023

Spectral Multistep Methods For The Scalable Simulation Of Time-Dependent Phenomena, Bailey Rester

Dissertations

Krylov subspace spectral (KSS) methods are high-order accurate, one-step explicit time-stepping methods for partial differential equations (PDEs) that also possess stability characteristic of implicit methods. Unlike other time-stepping approaches, KSS methods compute each Fourier coefficient of the solution from an individualized approximation of the solution operator of the PDE, using techniques developed by Golub and Meurant for approximating bilinear forms involving matrix functions. As a result, KSS methods scale effectively to higher spatial resolution.

This dissertation will present spectral multistep methods, explicit and implicit, designed through the combination of KSS methods and Adams methods. This combination allows spectral multistep methods …


The Influence Of Diamine Curing Additives On The Network Architecture Of Phthalonitrile Thermosetting Polymers, Tyler J. Richardson Apr 2023

The Influence Of Diamine Curing Additives On The Network Architecture Of Phthalonitrile Thermosetting Polymers, Tyler J. Richardson

Dissertations

Phthalonitrile monomers undergo diamine-promoted polymerization by a complex reaction mechanism involving two competitive cure pathways, forming two primary network architectures: linear polyisoindoline chains and branched triazine crosslinks. The influence of the diamine curing additive on the polymerization pathway, and the influence of the resulting network architectures on cured network properties, have not been adequately explored within the phthalonitrile field. Two structurally different diamine curing additives, bis[4-(3-aminophenoxy)phenyl] sulfone (mBAPS) and 1,3-phenylenebis((4-(4-aminophenoxy)phenyl)methanone) (AEK-134), were studied for the polymerization of resorcinol phenylphosphate phthalonitrile (RPPhPN), where the influence of diamine structure and concentration on the polymerization behavior, network architecture, and bulk thermal and thermomechanical …


Loss Scaling And Step Size In Deep Learning Optimizatio, Nora Alosily Apr 2023

Loss Scaling And Step Size In Deep Learning Optimizatio, Nora Alosily

Dissertations

Deep learning training consumes ever-increasing time and resources, and that is
due to the complexity of the model, the number of updates taken to reach good
results, and both the amount and dimensionality of the data. In this dissertation,
we will focus on making the process of training more efficient by focusing on the
step size to reduce the number of computations for parameters in each update.
We achieved our objective in two new ways: we use loss scaling as a proxy for
the learning rate, and we use learnable layer-wise optimizers. Although our work
is perhaps not the first …


Topological Data Analysis Of Weight Spaces In Convolutional Neural Networks, Adam Wagenknecht Apr 2023

Topological Data Analysis Of Weight Spaces In Convolutional Neural Networks, Adam Wagenknecht

Dissertations

Convolutional Neural Networks (CNNs) have become one of the most commonly used tools for performing image classification. Unfortunately, as with most machine learning algorithms, CNNs suffer from a lack of interpretability. CNNs are trained by using a training data set and a loss function to tune a set of parameters known as the layer weights. This tuning process is based on the classical method of gradient descent, but it relies on a strong stochastic component, which makes the weight behavior during training difficult to understand. However, since CNNs are governed largely by the weights that make up each of the …


Synthesis And Evaluation Of Biologically Active Phosphorous Heterocycles And Lipid A Antagonist Compounds, Saroj Kafle Apr 2023

Synthesis And Evaluation Of Biologically Active Phosphorous Heterocycles And Lipid A Antagonist Compounds, Saroj Kafle

Dissertations

Cyclophostin and cyclipostins are naturally occurring organophosphates with common structural core units and different phosphate ester substituents. Cyclophostin is a cyclic phosphate triester with a chiral center at phosphorous and C-3a carbon atom while the cyclipostins have characteristic alkyl substituents with varying chain lengths at the phosphate center. Long-chain substituted monocyclic phosphate (2b) and phosphonate (2a) analogs of cyclophostin and cyclipostin are promising inhibitors against serine hydrolases acetylcholinesterase with an IC50 in the nanomolar range.

Biologically active β-lactones and lactams owe their activity, in part, to ring strain. The ring opening of β-lactones and lactams …


Zonality In Graphs, Andrew Bowling Apr 2023

Zonality In Graphs, Andrew Bowling

Dissertations

Graph labeling and coloring are among the most popular areas of graph theory due to both the mathematical beauty of these subjects as well as their fascinating applications. While the topic of labeling vertices and edges of graphs has existed for over a century, it was not until 1966 when Alexander Rosa introduced a labeling, later called a graceful labeling, that brought the area of graph labeling to the forefront in graph theory. The subject of graph colorings, on the other hand, goes back to 1852 when the young British mathematician Francis Guthrie observed that the countries in a map …


High-Dimensional Variable Selection Via Knockoffs Using Gradient Boosting, Amr Essam Mohamed Apr 2023

High-Dimensional Variable Selection Via Knockoffs Using Gradient Boosting, Amr Essam Mohamed

Dissertations

As data continue to grow rapidly in size and complexity, efficient and effective statistical methods are needed to detect the important variables/features. Variable selection is one of the most crucial problems in statistical applications. This problem arises when one wants to model the relationship between the response and the predictors. The goal is to reduce the number of variables to a minimal set of explanatory variables that are truly associated with the response of interest to improve the model accuracy. Effectively choosing the true influential variables and controlling the False Discovery Rate (FDR) without sacrificing power has been a challenge …


Statistical Clustering Of Networks With Additional Information, Paul Atandoh Apr 2023

Statistical Clustering Of Networks With Additional Information, Paul Atandoh

Dissertations

As the online market grows rapidly, many companies and researchers are interested in analyzing product review dataset which includes ratings and text review data. In the first project, we mainly focus on analyzing the text review data. In the current literature, it is common to use only text analysis tools to analyze review dataset. But in our work, we propose a method that utilizes both a text analysis method such as topic modeling and a statistical network model to build network among individuals and find interesting communities. We introduce a promising framework that incorporates topic modeling technique to define the …


Using Visual Imagery To Develop Multiplication Fact Strategies, Gina Kling Apr 2023

Using Visual Imagery To Develop Multiplication Fact Strategies, Gina Kling

Dissertations

The learning of basic facts, or the sums and products of numbers 0–10 and their related differences and quotients, has always been a high priority for elementary school teachers. While memorization of basic facts has been a hallmark of elementary school, current recommendations focus on a more nuanced development of fluency with these facts. Fluency is characterized by the ability to demonstrate flexibility, accuracy, efficiency, and appropriate strategy use. Despite recommendations to focus on strategy use, there is insufficient information on instructional approaches that are effective for developing strategies, particularly for multiplication facts. Using visual imagery with dot patterns has …


Irregular Domination In Graphs, Caryn Mays Apr 2023

Irregular Domination In Graphs, Caryn Mays

Dissertations

Domination in graphs has been a popular area of study due in large degree to its applications to modern society as well as the mathematical beauty of the topic. While this area evidently began with the work of Claude Berge in 1958 and Oystein Ore in 1962, domination did not become an active area of research until 1977 with the appearance of a survey paper by Ernest Cockayne and Stephen Hedetniemi. Since then, a large number of variations of domination have surfaced and provided numerous applications to different areas of science and real-life problems. Among these variations are domination parameters …


Design And Implementation Of An Efficient Priority Queue Data Structure, James A. Rhodes Apr 2023

Design And Implementation Of An Efficient Priority Queue Data Structure, James A. Rhodes

Dissertations

Priority queues are one of the most useful data structures. Research to improve the efficiency of priority queues is on-going in the field of Computer Science. We have designed and implemented a priority queue based on buckets that improves the performance of applications that utilize min/max heaps. The data structure improves an application’s insertion time and deletion time, and thus its overall execution time. We demonstrate the performance improvements in a wide variety of applications. Every one of the applications that we implemented is well-known, and important in the Computer Science field. We also demonstrate that the performance gains over …


Socially Aware Natural Language Processing With Commonsense Reasoning And Fairness In Intelligent Systems, Sirwe Saeedi Apr 2023

Socially Aware Natural Language Processing With Commonsense Reasoning And Fairness In Intelligent Systems, Sirwe Saeedi

Dissertations

Although Artificial Intelligence (AI) promises to deliver ever more user-friendly consumer applications, recent mishaps involving fake information and biased treatment serve as vivid reminders of the pitfalls of AI. AI can harbor latent biases and flaws that can cause harm in diverse and unexpected ways. It is crucial to understand the reasons for, mechanisms behind, and circumstances under which AI can fail. For instance, a lack of commonsense reasoning can lead to biased or unfair decisions made by Machine Learning (ML) systems. For example, if an ML system is trained on data that is biased or unrepresentative of the real …


Analysis Of U.S. Housing Markets Using Advanced Econometric Models And Machine Learning Algorithms, Cody Kirby Apr 2023

Analysis Of U.S. Housing Markets Using Advanced Econometric Models And Machine Learning Algorithms, Cody Kirby

Dissertations

The Great Recession is the most recent reminder in U.S. history of the important relationship that exists between monetary policy and housing market activity. Since World War II, eight U.S. recessions have followed downturns in housing. A decline in the housing market results in the balance sheet deterioration of homeowners, financial institutions, private organizations, central banks, governing bodies, and foreign countries. The ability to understand the relationship between monetary policy and housing market activity, and to better forecast housing prices, allows for better planning by all economic agents.

This study answers the following research questions. (1) How have monetary policy …


Development Of Innovative Multi-Drug Approaches To Counteract Illicit Drug Abuse In The Uae Population, Manal Ali Alhefeiti Apr 2023

Development Of Innovative Multi-Drug Approaches To Counteract Illicit Drug Abuse In The Uae Population, Manal Ali Alhefeiti

Dissertations

The abuse of addictive substances is on the rise in the United Arab Emirates (UAE) population. Consequently, the UAE government spends about Dhs 5.5 billion annually on the rehabilitation of drug addicts. Blood, urine, and hair tests can reveal signs of sporadic or chronic drug use. Given the list of banned chemicals in the UAE, our main objective in this work was to develop a novel analytical method to identify and measure banned substances, especially prescription and over-the-counter drugs in the UAE. We developed and validated a rapid, sensitive and reliable liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) approach for the targeted …


Ab-Initio Investigation Of 2d Materials For Gas Sensing, Energy Storage And Spintronic Applications, Saba Khan Apr 2023

Ab-Initio Investigation Of 2d Materials For Gas Sensing, Energy Storage And Spintronic Applications, Saba Khan

Dissertations

The field of Two Dimensional (2D) materials has been extensively studied since their discovery in 2004, owing to their remarkable combination of properties. My thesis focuses on exploring novel 2D materials such as Graphene Nanoribbon (GNR), holey carbon nitride C2N, and MXenes for energy storage, gas sensing, and spintronic applications, utilizing state-of-the-art techniques that combine Density Functional Theory (DFT) and Non-Equilibrium Greens Functions (NEGF) formalism; namely Vienna Ab-initio Simulation Package (VASP) and Atomistic Toolkit (ATK) package.
/="/">Firstly, on the side of gas sensing, the burning of fossil fuels raises the level of toxic gas and contributes to …


Metal Oxide Based Materials For High Performance Supercapacitors, Hammad Mueen Arbi Apr 2023

Metal Oxide Based Materials For High Performance Supercapacitors, Hammad Mueen Arbi

Dissertations

Recent years have seen a healthy rise in the research and development of sustainable and renewable energy storage systems due to the pressing need to conserve natural resources and cut energy use. Due to the rapid growth in global population lately, there is a tremendous demand for energy to fulfill the ever-increasing needs. Innovative alternative energy sources and energy storage techniques are of tremendous interest for dealing with these current world issues. One promising solution for this is the recent research trend for achieving reliable and cost-effective high power and high energy density energy storage devices. On the basis of …


Impact Of Teaching Mathematics With Four Teaching Strategies On Fifth Grade Students’ Learning Of Fractions Addition And Subtraction, Nabil Riziq Al Farra Apr 2023

Impact Of Teaching Mathematics With Four Teaching Strategies On Fifth Grade Students’ Learning Of Fractions Addition And Subtraction, Nabil Riziq Al Farra

Dissertations

There are different tools, resources, and materials that mathematics teachers may use to enhance the teaching and learning processes under many types of teaching strategies such as technology (e.g., videos and virtual manipulatives), real objects (e.g., concrete manipulatives), and other teaching strategies are traditional (e.g., lectures). Some of the most important things that a teacher has to consider is the students’ learning needs and how to reach to their minds by different teaching strategies with a variety of resources and assess which are more effective in students’ learning anddevelopment in mathematics.

The purpose of this study is to investigate the …


Nano-Supported Biocatalysts For Efficient Wastewater Remediation, Khadega Abobaker Al-Maqdi Apr 2023

Nano-Supported Biocatalysts For Efficient Wastewater Remediation, Khadega Abobaker Al-Maqdi

Dissertations

The existence of various bioactive organic pollutants in wastewater and municipal water sources has raised concerns regarding their potential effects on human health. As a result, different techniques are being explored to effectively break down these persistent organic pollutants. Peroxidases have recently emerged as a new approach to remediation that may have advantages over traditional methods. However, evaluating the effectiveness of different peroxidases in breaking down various emerging pollutants can be time-consuming and difficult. In this study, a quick and reliable method was developed to test the degradability of 21 emerging pollutants by five different peroxidases (soybean peroxidase, chloroperoxidase, lactoperoxidase, …


Lax Integrability And Solution Methods For The Nonlinear Schrödinger Equation With External Potentials: Exact Solutions And Applications, Laila Yahya Al Sakkaf Apr 2023

Lax Integrability And Solution Methods For The Nonlinear Schrödinger Equation With External Potentials: Exact Solutions And Applications, Laila Yahya Al Sakkaf

Dissertations

The investigation of a nonlinear differential equation (NLDE) integrability is the foundation for understanding and predicting the behavior of systems that are governed by that NLDE. The existence of a Lax pair (LP) representation is a reliable indicator of the indicator of the integrability of an NLDE. If an NLDE admits an LP, it is considered integrable in the LP sense, and this has important implications for the behavior and solutions of the system. The LP plays a crucial role in many powerful analytical solution methods for solving NLDEs. One such method is the Darboux transformation (DT), which allows for …


A Multiscale Linkage Between Riverscape And Fish Community Coevolution, Loren W. Stearman Mar 2023

A Multiscale Linkage Between Riverscape And Fish Community Coevolution, Loren W. Stearman

Dissertations

Sediment dynamics are foundational to stream and watershed morphology. Yet aquatic ecologists have relied on an oversimplified model of sediment dynamics characterizing sediments as agents of stream bed burial, and which fails to describe many types of aquatic habitat evolution. In this dissertation I employ both fluvial geomorphic and ecological frameworks to gain a deeper understanding of how sediment dynamics shape stream morphology and fish community evolution at multiple scales. Using a paired historic and contemporary approach, I analyzed geomorphic evolution and fish community change in the Bayou Pierre, Mississippi, from the 1980s to recent. Patterns of erosion due to …


Design And Fabrication Of Single-Chain Nanoparticles, Vitrimers, Bottlebrush And Comb Polymers, Logan Dugas Mar 2023

Design And Fabrication Of Single-Chain Nanoparticles, Vitrimers, Bottlebrush And Comb Polymers, Logan Dugas

Dissertations

The introduction of novel dynamic exchange chemistries into polymer chains and networks has shown great potential of giving next generation polymeric materials. Within the scope of this thesis, dynamic chemistry is employed to realize single-chain nanoparticles, vitrimer networks, bottlebrush and comb polymers. CHAPTER I provides a broad introduction to the topics at hand, focusing upon the techniques utilized to achieve such materials with relevant literature and understanding of the techniques and architectures explored. CHAPTER II focuses upon the synthesis of single-chain nanoparticles via a copolymerization of polyisobutylene macromonomers with norbornene monomers equipped with pendant anthracene moieties. Through this work, the …


The Synthesis, Characterization, And Utilization Of Functionally Diverse Romp-Based Bottlebrushes, Cheyenne Liu Mar 2023

The Synthesis, Characterization, And Utilization Of Functionally Diverse Romp-Based Bottlebrushes, Cheyenne Liu

Dissertations

Bottlebrush polymers have garnered interest in many disciplines for their unique structure-property characteristics and potential applications. These polymers typically exhibit extended rodlike conformations as a result of sterically crowded side-chains. Further, extensive work has focused on expanding the synthetic toolbox for these systems, resulting in excellent molecular weight control, diverse functional group utility and corresponding stimuli-responsive behaviors. This dissertation examines both synthetic and stimuli-responsive tools in the context of bottlebrush systems.

A broad overview of bottlebrush characteristics, synthesis, and applications is discussed in CHAPTER I. CHAPTER II focuses on the use of a chain-transfer agent in the ring-opening metathesis polymerization …


Identification Of Students At Risk Of Low Performance By Combining Rule-Based Models, Enhanced Machine Learning, And Knowledge Graph Techniques, Balqis Mubarak Al Braiki Mar 2023

Identification Of Students At Risk Of Low Performance By Combining Rule-Based Models, Enhanced Machine Learning, And Knowledge Graph Techniques, Balqis Mubarak Al Braiki

Dissertations

Technologies and online learning platforms have changed the contemporary educational paradigm, giving institutions more alternatives in a complex and competitive environment. Online learning platforms, learning-based analytics, and data mining tools are increasingly complementing and replacing traditional education techniques. However, academic underachievement, graduation delays, and student dropouts remain common problems in educational institutions. One potential method of preventing these issues is by predicting student performance through the use of institution data and advanced technologies. However, to date, scholars have yet to develop a module that can accurately predict students’ academic achievement and commitment. This dissertation attempts to bridge that gap by …


Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman Jan 2023

Magnetic Interactions In Open-Shell Conjugated Polymers, Michael Steelman

Dissertations

Most materials are closed shell in which every electron participates in a bond, resulting in unremarkable magnetometry signatures and functionalities. While rare, modern technologies rely on magnetic materials in which unpaired electrons are localized to inorganic atomic centers. In recent decades, a collection of organic open-shell π-conjugated molecules have shown magnetic ordering, albeit at exceedingly low temperatures; a result of weak noncovalent intermolecular interactions limiting long range electronic exchange. Thus, practically applicable sp orbital magnetism that persists at or above room temperature remains a grand challenge for chemistry and physics. Despite the wide variety of chemical structures afforded by organic …


Method Development For The Quantification Of Heavy Metals In Biological Matrices And Its Application To Clinical And Environmental Samples, Michelle Catherine Gende Jan 2023

Method Development For The Quantification Of Heavy Metals In Biological Matrices And Its Application To Clinical And Environmental Samples, Michelle Catherine Gende

Dissertations

A three-fold approach was taken to develop a method for the detection of heavy metals in different matrices and had to be performed sequentially. The first was to develop a method capable of quantifying lead in complex matrices by graphite furnace atomic absorption (GFAA). The developed method needed to meet specific analytical requirements, namely, to be robust, sensitive, and accurate. Initially, four different sample preparation methods were explored for the quantification of lead using Escherichia coli (E. coli) as a sample matrix. The sample preparation procedures attempted were acidic dilution, matrix modification, conventional heating digestion, and microwave assisted acid digestion …


The Relationships Between Flow, Mathematics Self-Efficacy, And Mathematics Anxiety Among International Undergraduate Students In The United States, Samah Abduljabbar Jan 2023

The Relationships Between Flow, Mathematics Self-Efficacy, And Mathematics Anxiety Among International Undergraduate Students In The United States, Samah Abduljabbar

Dissertations

Problem

A worldwide problem, math anxiety is defined as an anxious state with an unpleasant feeling of tension characterized by fear of failing to achieve mathematics targets. Psychologically, math anxiety involves anxiety, tension, discomfort, nervousness, fear, shock, and insecurity. Math anxiety has been perceived as a key influencer of reduced math achievement, and avoidance of math-related careers. On the other hand, abilities, flow, interests, and psychological conditions contribute to student mathematics success. Belief in one's ability to perform a specific task boosts self-efficacy, which has been studied widely as a predictor of student academic performance. When students are interested in, …


Design And Synthesis Of Novel Antibiotics And Anticancer Agents Targeting Pharmaceutically Relevant Enzymes, Sebastian Flieger Jan 2023

Design And Synthesis Of Novel Antibiotics And Anticancer Agents Targeting Pharmaceutically Relevant Enzymes, Sebastian Flieger

Dissertations

Boron neutron capture therapy (BNCT) is a binary radiotherapeutic modality for cancer treatment, in which delivery agents containing 10B atoms are transported into tumor cells and then irradiated with low-energy thermal neutrons. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that are involved in the remodeling and degradation of all components of the extracellular matrix (ECM). Overexpressed levels of MMP activity have been implicated in several disease states including tumor growth and metastasis. We have appended a borane-rich carborane cluster onto MMP-targeting pharmacophores to enable delivery of 10B atoms to a tumor. Herein, we describe the molecular docking experiments …