# Physical Sciences and Mathematics Commons™

Articles 1 - 30 of 6431

## Full-Text Articles in Physical Sciences and Mathematics

Named Entity Recognition From Biomedical Text, Maged Guirguis Feb 2023

#### Named Entity Recognition From Biomedical Text, Maged Guirguis

##### Theses and Dissertations

As vast amounts of unstructured data are becoming available digitally, computer-based methods to extract relevant and meaningful information are needed. Named entity recognition (NER) is the task of identifying text spans that mention named entities, and to classify them into predefined categories. Despite the existence of numerous and well-versed NER methods, the bio-medical domain remains under-studied. The objective of this research is to identify an efficient technique for NER tasks from biomedical data. This is achieved by investigating using deep learning technologies namely pre-trained BERT [1] model and its variances SciBERT [2] and BioBERT [3]. Preprocessing the data before passing …

#### Azimuthal Anisotropy Of Different Quark-Flavored Particles In High Energy "Simulated" Proton-Proton Collisions, Mahmoud Rateb

##### Theses and Dissertations

Anisotropic flow in high energy heavy-ion collisions is taken as a key evidence for the formation of QGP for brief seconds right after the collisions. Hydrodynamic models including QGP formation are accurate at predicting the azimuthal anisotropy of the produced particles at low transverse momenta. At high momenta however, hydrodynamic models predict no azimuthal anisotropy for particles of different masses and quark-flavors; the logic being that because of their high momenta, the particles pass through the media without having any time to have any reactivity. This is contrary to results from experiments where measurements of particles of different quark flavors …

#### Carbon Dioxide Capture Potential Of Chitosan-Nanocrystalline Cellulose Aerogel Composite Materials: Synthesis, Functionalization, And Characterization, Victor Oghenekohwo

##### Theses and Dissertations

The carbon dioxide capture technology has been established as an invaluable player in the current global efforts to allay the warming of the planet and climate change. In this connection, the study centers on the valorization of waste organic materials for the application described herein. The sorbents, sourced from a combination of by-products of food processing and agricultural residue waste products, viz. seafood waste and sugarcane bagasse, showed prospects for selective carbon dioxide capture, adsorbing up to 5.78 mg/g of the gas at 273 K and 2.82 mg/g at 298 K, as observed on the Micromeritic ASAP 2020 surface area …

#### Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin

##### Theses and Dissertations

Thin-film nanocomposite (TFN) desalination membranes were prepared based on a polyethersulfone (PES) support, where the polyamide (PA) layer was embedded with amine-functionalized graphene oxide (GO). The effect of adding various concentrations of functionalized and un-functionalized GO on the desalination performance, hydrophilicity, and morphology of the membranes was additionally assessed throughout this work. Scanning electron microscopy (SEM) measurements were used to assess the morphology of the membranes in combination with Brunauer-Emmett-Teller (BET) analysis. Contact angle measurements were used to gauge the hydrophilicity of the synthesized membranes. The membrane with the best desalination performance contained 1x10-3 wt/vol% of functionalized GO in …

Jan 2023

#### Machine Learning Models Interpretability For Malware Detection Using Model Agnostic Language For Exploration And Explanation, Ikuromor Mabel Ogiriki

##### Theses and Dissertations

The adoption of the internet as a global platform has birthed a significant rise in cyber-attacks of various forms ranging from Trojans, worms, spyware, ransomware, botnet malware, rootkit, etc. In order to tackle the issue of all these forms of malware, there is a need to understand and detect them. There are various methods of detecting malware which include signature, behavioral, and machine learning. Machine learning methods have proven to be the most efficient of all for malware detection. In this thesis, a system that utilizes both the signature and dynamic behavior-based detection techniques, with the added layer of the …

Using Dielectric Scatters To Selectively Excite Embedded Eigenstates In Cavity Resonators, Olugbenga Joshua Gbidi Jan 2023

#### Using Dielectric Scatters To Selectively Excite Embedded Eigenstates In Cavity Resonators, Olugbenga Joshua Gbidi

##### Theses and Dissertations

Bound states in the continuum (BICs) are waves that remain in the continuous spectrum of radiating waves that carry energy, however, still localized within the spectrum. BICs, also embedded eigenmodes, exhibit high quality factors that have been observed in optical and acoustic waveguides, photonic structures, and other material systems. Presently, there are limited means to select these BICs in terms of the quality factor and their excitation. In this work, we show that a different type of BIC, Quasi-BICs (Q-BICs), in open resonators can have their quality attuned by introducing embedded scatters. Using microwave cavities and dielectric scatters as an …

#### Short-Range Magnetic Correlations, Spontaneous Magnetovolume Effect, And Local Distortion In Magnetic Semiconductor Mnte, Raju Baral

##### Theses and Dissertations

The antiferromagnetic semiconductor MnTe has recently attracted significant interest as a potential high-performance thermoelectric material. Its promising thermoelectric properties are due in large part to short-range magnetic correlations in the paramagnetic state, which enhance the thermopower through the paramagnon drag effect. Using magnetic pair distribution function (mPDF) analysis of neutron total scattering data, we present a detailed, real-space picture of the short-range magnetic correlation in MnTe, offering a deeper view into the paramagnon drag effect and the nature of the correlated paramagnetic state. We confirm the presence of nanometer-scale antiferromagnetic correlations far into the paramagnetic state, show the evolution of …

#### Quantifying Volatile Fatty Acid Concentrations During The Pretreatment And Anaerobic Digestion Process, Sascha Boutelle

##### Theses and Dissertations

Producing renewable energy from biomass or from the wastewater treatment process has gained momentum in the past 20 years. Anaerobic digestion has historically been used as one step in the waste treatment process, to both reduce the mass of waste that needs to be disposed of and to generate biogas. This process is typically only able to reduce 30-40% of the waste mass because of the recalcitrant nature of the waste streams being treated. Anaerobic pretreatment with the thermophilic bacteria Caldicellulosiruptor bescii (C. bescii) has been proven to increase the percentage of mass digested and consequently increase methane production to …

Effect Of X-Ray Illumination On Magnetic Domain Memory In [Co/Pd]/Irmn Multilayers, Colby Singint Walker Dec 2022

#### Effect Of X-Ray Illumination On Magnetic Domain Memory In [Co/Pd]/Irmn Multilayers, Colby Singint Walker

##### Theses and Dissertations

This thesis focuses on investigating the possible x-ray illumination effects on the magnetic domain memory (MDM) in magnetic [Co/Pd]IrMn multilayers. In this material, MDM is induced via exchange couplings between the ferromagnetic Co/Pd layer and the antiferromagnetic IrMn layer. To carry out this investigation, we have used magneto-transport and x-ray resonant magnetic scattering. The use of magneto-transport in-situ at synchrotron x-ray scattering facility has allowed us to follow the gradual effect of x-ray illumination on the amount of exchange bias, initially present after field cooling the material. With our in-situ measurements we have been able to see that x-ray illumination …

A Usability Study Of Fido2 Hardware Tokens On Mobile Devices, Stephen Lambert Dec 2022

#### A Usability Study Of Fido2 Hardware Tokens On Mobile Devices, Stephen Lambert

##### Theses and Dissertations

Passwords as the primary form of authentication on the web have many issues, such as password re-use across sites and difficulty in remembering secure passwords. The FIDO Alliance has created a passwordless system that has with support from companies like Google, Apple, and Microsoft: FIDO2. Studies have shown so far that users find FIDO2 usable on personal computers, but no work has been published on its usability on mobile devices. I conducted a lab study in which participants used FIDO2 passwordless authentication with hardware tokens on a mobile phone. Participants found FIDO2 usable on mobile devices, but had similar fears …

Dec 2022

#### Determining Figure Skating Jump Under-Rotation In Real-Time Using Imu Sensors During Practice, Duncan O. Furgeson

##### Theses and Dissertations

We explore the use of machine learning to detect under-rotation in figure skating jumps. Under- rotation in jumps is difficult for the skater to sense but learning to recognize under-rotation is an impor- tant part of learning proper jump technique. To address this difficulty, we present the Under-rotation Monitor, or UR Monitor, a system for detecting under-rotated figure skating jumps in real-time. UR Monitor uses a single inertial measurement unit (IMU) attached to the skater's waist that sends a stream of accelerometer and gyroscope data to a mobile phone via Bluetooth. The mobile phone creates and sends an input vector …

Computational Studies Of Dinuclear Catalytic Reaction Mechanisms, James Curtis Coombs Iii Dec 2022

#### Computational Studies Of Dinuclear Catalytic Reaction Mechanisms, James Curtis Coombs Iii

##### Theses and Dissertations

Heterodinuclear and homodinuclear metal complexes with a direct metal-metal interaction offer the potential for unique catalysis due to cooperativity effects that impact reaction mechanisms, reactivity, and selectivity. Quantum-chemical density functional theory (DFT) calculations can directly examine the origin of dinuclear reactivity and selectivity effects. Chapter 1 provides a short overview of heterodinuclear and homodinuclear catalysts that have been experimentally and computationally examined. Chapter 2 reports our study using DFT methods to understand the mechanism and reactivity of a heterodinuclear Co-Zr catalyst with phosphinoamide ligands that catalyzes a Kumada coupling between alkyl halides and alkyl Grignards. Chapter 3 reports DFT calculations …

Wildfire Modeling With Data Assimilation, Andrew Johnston Dec 2022

#### Wildfire Modeling With Data Assimilation, Andrew Johnston

##### Theses and Dissertations

Wildfire modeling is a complex, computationally costly endeavor, but with droughts worsening and fires burning across the western United States, obtaining accurate wildfire predictions is more important than ever. In this paper, we present a novel approach to wildfire modeling using data assimiliation. We model wildfire spread with a modification of the partial differential equation model described by Mandel et al. in their 2008 paper. Specifically, we replace some constant parameter values with geospatial functions of fuel type. We combine deep learning and remote sensing to obtain real-time data for the model and employ the Nelder-Mead method to recover optimal …

Complete Equitable Decompositions, Joseph Paul Drapeau Dec 2022

#### Complete Equitable Decompositions, Joseph Paul Drapeau

##### Theses and Dissertations

A well-known result in spectral graph theory states that if a graph has an equitable partition then the eigenvalues of the associated divisor graph are a subset of the graph's eigenvalues. A natural question question is whether it is possible to recover the remaining eigenvalues of the graph. Here we show that if a graph has a Hermitian adjacency matrix then the spectrum of the graph can be decomposed into a collection of smaller graphs whose eigenvalues are collectively the remaining eigenvalues of the graph. This we refer to as a complete equitable decomposition of the graph.

Structural Reasoning With Rational Expressions, Dana Steinhorst Dec 2022

#### Structural Reasoning With Rational Expressions, Dana Steinhorst

##### Theses and Dissertations

Many students struggle to make sense of algebraic expressions in math. This lack of understanding results in students making symbolic manipulation errors, hindering their procedural fluency. Researchers believe these errors are linked to students' lack of structural reasoning. While research has shown that students rarely engage in expert structural reasoning, little is known about how students actually reason structurally. In this study, I interviewed six high school calculus students to study the way they identified, matched, and evaluated structures as they solved problems involving rational expressions and equations. I analyzed the participant interviews and outlined the matching process they used …

Developing A Quantitative Understanding Of U-Substitution In First-Semester Calculus, Leilani Camille Heaton Fonbuena Dec 2022

#### Developing A Quantitative Understanding Of U-Substitution In First-Semester Calculus, Leilani Camille Heaton Fonbuena

##### Theses and Dissertations

In much of calculus teaching there is an overemphasis on procedures and manipulation of symbols and insufficient emphasis on conceptual understanding of calculus topics. As such students to struggle to understand and use calculus ideas in applied settings. Research shows that learning calculus topics from a quantitative reasoning-perspective results in more powerful and flexible conceptions of calculus topics like integration. However, topics beyond introducing integrals and the Fundamental Theorem of Calculus, like u-substitution, have yet to be explored from a quantity-based perspective. In this study, I conducted a set of two clinical interviews where we discussed quantitative meanings of integrals, …

#### Determination Of A Catalytic Mechanism By Time Resolved Fourier Transform Infrared Spectroscopy And Time Domain Analysis Of Data From Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Jacob T. Davis

##### Theses and Dissertations

Heterobimetallic catalysts offer large potential for efficient and selective catalysis of a wide range of reactions. Better understanding of these catalytic mechanisms could yield further improvement in their catalytic abilities. Cp(CO)2Fe-Cu(IPr) (IPr = N,N-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) is a catalyst that has been reported to catalyze arene borylation. The catalytic mechanism of this catalyst that had been previously proposed had the initial step being a metal-metal cleavage. However, computational modeling suggested an alternate mechanism that could be more energetically favorable. Rather than a metal-metal cleavage as the initial step, we proposed a photoactivated carbonyl dissociation. To support this proposition, we performed time resolved …

#### Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging Of Defect-Bearing Ablator Materials In Extreme Conditions, Daniel S. Hodge

##### Theses and Dissertations

Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source …

Dec 2022

#### Zeros Of A Family Of Complex-Valued Harmonic Rational Functions, Alexander Lee

##### Theses and Dissertations

The Fundamental Theorem of Algebra is a useful tool in determining the number of zeros of complex-valued polynomials and rational functions. It does not, however, apply to complex-valued harmonic polynomials and rational functions generally. In this thesis, we determine behaviors of the family of complex-valued harmonic functions $f_{c}(z) = z^{n} + \frac{c}{\overline{z}^{k}} - 1$ that defy intuition for analytic polynomials. We first determine the sum of the orders of zeros by using the harmonic analogue of Rouch\'e's Theorem. We then determine useful geometry of the critical curve and its image in order to count winding numbers by applying the harmonic …

Identity Work To Teach Mathematics For Social Justice, Navy B. Dixon Dec 2022

#### Identity Work To Teach Mathematics For Social Justice, Navy B. Dixon

##### Theses and Dissertations

In this thesis, mathematics educators are conceptualized as individuals with multiple, simultaneous figured worlds that inform their decisions while planning. The study explores how two mathematics educators negotiated and orchestrated their figured worlds to plan two mathematics lessons for social justice. The results highlight how numerous the figured worlds each participant surfaced through background interviews. Some of the figured worlds were elicited by the interview questions (i.e., Race, Family, Social Justice Teaching) but other figured worlds organically surfaced through the interviews (i.e., Sexuality, Community, Activism, Critical Information Consumption). A discursive analysis of a selection of these figured worlds revealed conceptualizations …

Precise Measurement Of The Nuclear Dependence Of The Emc Effect In Light Nuclei, Abishek Karki, Abishek Karki Dec 2022

#### Precise Measurement Of The Nuclear Dependence Of The Emc Effect In Light Nuclei, Abishek Karki, Abishek Karki

##### Theses and Dissertations

Measurements of inclusive electron scattering cross-section ratios from light nuclei over a wide range of the Björken �� (0.3 < �� < 1) up to �� 2 = 8.3 GeV2 were made as part of experiment E10-10-008, which was conducted in Hall C at the Thomas Jefferson National Accelerator Facility. The measurements were performed using a beam energy of 10.602 GeV and an average beam current of 45 ��A. This dissertation provides a thorough description of the experiment as well as the extracted ratios of inclusive nuclear cross-sections with respect to the deuterium cross-sections (the EMC effect) for the targets 9 Be, 12 C, 10 B, and 11 B. The …

Assessing Wood Failure In Plywood By Deep Learning/Semantic Segmentation, Ramon Ferreira Oliveira Dec 2022

#### Assessing Wood Failure In Plywood By Deep Learning/Semantic Segmentation, Ramon Ferreira Oliveira

##### Theses and Dissertations

The current method for estimating wood failure is highly subjective. Various techniques have been proposed to improve the current protocol, but none have succeeded. This research aims to use deep learning/semantic segmentation using SegNet architecture to estimate wood failure in four types of three-ply plywood from mechanical shear strength specimens. We trained and tested our approach on custom and commercial plywood with bio-based and phenol-formaldehyde adhesives. Shear specimens were prepared and tested. Photographs of 255 shear bonded areas were taken. Forty photographs were used to solicit visual estimates from five human evaluators, and the remaining photographs were used to train …

Augmented Reality Fonts With Enhanced Out-Of-Focus Text Legibility, Mohammed Safayet Arefin Dec 2022

#### Augmented Reality Fonts With Enhanced Out-Of-Focus Text Legibility, Mohammed Safayet Arefin

##### Theses and Dissertations

In augmented reality, information is often distributed between real and virtual contexts, and often appears at different distances from the viewer. This raises the issues of (1) context switching, when attention is switched between real and virtual contexts, (2) focal distance switching, when the eye accommodates to see information in sharp focus at a new distance, and (3) transient focal blur, when information is seen out of focus, during the time interval of focal distance switching. This dissertation research has quantified the impact of context switching, focal distance switching, and transient focal blur on human performance and eye fatigue in …

#### Geologic Mapping Of The Sparta 7.5-Minute Quadrangle In Northern Mississippi Via Remote Sensing, Traditional Geologic Survey, And Applied Geospatial Information Systems Methods, Rayford Dean Parnell

##### Theses and Dissertations

Traditional geologic mapping involves substantial time and labor in the field as geologic contacts are manually examined and interpreted. The processes of mapping geologic contacts can be condensed into a quicker and less laborious process using advances in remote sensing and GIS (geospatial information systems), including increased resolution and computerized data management and interpretation. Application of these advances reduces the costs and time of geologic mapping. The Sparta 7.5-minute quadrangle provides a mostly unaltered view of regional Paleocene and Upper Cretaceous geology due to its rural locale, lack of development, and stream topography. Recently LiDAR (Light Detection And Ranging) survey …

Dec 2022

#### Mitigating The Shrink-Swell Capacities Of The Yazoo Clay Through Application Of Lime And Biochar, Austin Alan Brister

##### Theses and Dissertations

Shrinking and swelling in Yazoo Clay is a cause of concern for construction projects in Mississippi. This thesis investigated the effects of adding lime and Douglas Fir biochar on the shrinking and swelling capabilities of Yazoo Clay. Samples of Yazoo Clay were mixed with the additives in defined ratios and subjected to the free swell test and the COLE(rod) test. Biochar addition reduced the COLE(rod) of the samples a large amount, while increasing the swelling potential of the clay samples. The addition of lime slightly reduced both the shrinking and swelling potentials of the samples. The mineralogical variability of Yazoo …

#### Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard

##### Theses and Dissertations

The Starkville Quadrangle is a hotspot for geological research. The Late Cretaceous is represented by the Demopolis Formation in the northeast corner of the quadrangle, followed by the Ripley Formation, and the Prairie Bluff Formation. The K-Pg boundary is exposed in the quadrangle, and the remarkable paleontology is of global importance. The Clayton Formation is the first Paleocene unit. Where the Clayton Formation channel sands are in contact with the underlying Prairie Bluff Formation, springs occur. Springs were a rare source of water in the Black Prairie and spurred the settlement of the area over 10,000 years ago. The Paleocene …

Dec 2022

#### From The Sky To The Smartphone: Communicating Weather Information In A Digital Age, Cole M. Vaughn

##### Theses and Dissertations

As new technology has emerged in the digital era, the public can now choose from a variety of new media from which to get weather information. Weather applications (apps) and social media have emerged as some of the popular new media. This study sought to understand the extent to which these new media are used, how weather apps are perceived, how the news media used Twitter during Hurricane Irma, and how the public engaged with the news media’s tweets. A survey and dataset of tweets were used to evaluate the research questions and hypotheses of this research. The study found …

#### Facies Architecture And Provenance Of The Highly Progradational, Fluvial Dominated Deltaic Depositional System Of The Cretaceous Nanushuk Formation On The North Slope Of Alaska, Sarah N. Naone

##### Theses and Dissertations

The Cretaceous Nanushuk Formation of northern Alaska records extremely rapid shoreline progradation across the Colville Basin during the Albian-Cenomanian epochs. Additionally, it records a period of tectonic realignment in the region, as the main sediment source began to transition from the Chukotkan orogeny to the west to a more local sediment source of the proximal Brooks Range to the south. Through detailed outcrop characterization and 3-D modeling of three exposed outcrops along the axial trend of the Colville Basin on the North Slope and the Upper section of the Nanushuk, this study clarifies the relative timing of the early Brookian …

#### Analyzing Business-Focused Social Networks In Hiring: The Influence Of A Job Candidate's Network On A Recruiter's Hiring Recommendation, Hannah V. Kibby

##### Theses and Dissertations

Social media has altered the ways in which people interact. Business-focused social media profiles, such as those on LinkedIn, can act as a proxy for a traditional resume. However, these websites differ from a traditional resume in that information presented is sometimes informal, personal, and irrelevant to the member’s career. Furthermore, HR employees are able to view a job candidate’s social network. This research investigates the influence of a recruiter’s knowledge of an applicant’s professional network on the recruiter’s perception of the applicant’s trustworthiness and hence their willingness to take risk in the hiring relationship. A review of the literature …

Dec 2022

#### Using Xbeach To Describe The Performance Of An Intertidal Vegetation Shoreline Stabilization Treatment, Elizabeth Winter

##### Theses and Dissertations

The purpose of this project is to predict the hydrodynamic and morphodynamics of an engineered vegetation-only shoreline restoration project in Little Lagoon, Alabama under different storm and sea level rise scenarios. Little Lagoon is a shallow, single-inlet lagoon located in Baldwin County, Alabama that has been experiencing shoreline erosion for the past 28 years. A living shoreline using vegetation only (Spartina alterniflora) was implemented in the southwest corner of the lagoon, located within Bon Secour National Wildlife Refuge, to create habitat, improve water quality, and prevent future erosion. This research compares “with-project” and “without-project” hydrodynamics and morphodynamics using XBeach in …