Physical Sciences and Mathematics Commons^™

Numerical Studies Of Semiclassical Light Storage Using The Coherent Atomic Transfer Function, Zachary T. Johnson

Theses and Dissertations

Quantum communication through photons relies on photonic storage to preserve quantum states. However, when photons interact with matter, quantum information becomes distorted. A recently developed semi-classical analytical model predicts output light pulses from an electromagnetically induced transparency (EIT) system. Using the predictions, the model known as the Coherent Atomic Transfer (CAT) Function, is capable of predicting the stored pulse or reconstructing the original pulse. Using numerical convolution and deconvolution with the CAT function as an analog of the point spread function of Fourier optics can provide insights on the effects of EIT storage on the retrieved pulse. Blind deconvolution is …

Isotopic Analysis Of Lithium Hydroxide Monohydrate Using Laser-Induced Breakdown Self-Reversal Isotopic Spectrometry (Libris) And Machine Learning, Madison R. Moran

Theses and Dissertations

High-resolution Laser-Induced Breakdown Self-Reversal Isotopic Spectrometry (LIBRIS) is implemented to record the 15.8 pm Li I 670.8 nm isotopic shift in LiOH · H₂O samples of varying 6, 7Li abundance. A simple univariate linear regression demonstrates an acquired isotopic shift of 13.813 ± 1.21 pm in samples varying from 3 to 95 ⁶Li at%. Supervised machine learning regressions are trained on self-reversal wavelength locations in order to quantify ⁶Li abundance. A stacked ensemble using two base learners yields the superlative characterization of 6Li abundance with RMSE of 5.66 at% and detection limit of 18.8 at%. Using …

Transfer Efficiencies Of Surface-To-Surface Transport Of Micron-Sized Actinide Surrogate Particles, Austin R. Powell

Theses and Dissertations

Particle effluent of varying sizes is released during routine activities within laboratory environments and these particles can come in contact with a wide range of surfaces. Particles of micron size or smaller can be especially pervasive and can transfer between multiple subsequent surfaces, leading to the progressive contamination of a laboratory. Understanding the transport dynamics of micron sized particles will help inform facility personnel of the possibility of contamination by these potentially hazardous materials of interest. In this research, the transfer efficiency of micron sized surrogate actinide particles (Europium-doped Gadolinium Oxysulfide (EGOS)) is measured for multiple materials, between two particle …

Reflected Laser Light As A Diagnostic Insight For Femtosecond Laser-Plasma Coupling, David S. Stiles

Theses and Dissertations

High-energy laser technology is critical for military, scientific, and industrial applications, but traditional mixed-radiation facilities are hindered by cost, scheduling constraints, and lack of portability. A high-repetition-rate, cost-effective alternative is needed to meet evolving application needs and timelines. This study investigates changes in reflected laser intensity to diagnose coupling efficiency and optimize energetic particle generation in ultraintense laser-target interactions. Using an ultraintense 35 femtosecond, 9 - 12 mJ laser and a deuterated water target, reflected laser light was captured via high-resolution imaging, while energetic electron and X-ray data were collected using a custom spectrometer and ion chamber, respectively. Statistical analysis …

Grassmannian Codes From Stratified Frames, William J. Brinkley

Theses and Dissertations

An equichordal tight fusion frame (ECTFF) is a finite sequence of equi-dimensional subspaces of a Euclidean space that achieves equality in Conway, Hardin and Sloane's simplex bound. Every ECTFF is an optimal Grassmannian code with respect to the chordal distance. We introduce a method for constructing an ECTFF from any finite sequence of unit norm tight frames that happen to be stratified in a certain sense. We moreover show how to construct stratified unit norm tight frames from a difference family for a finite abelian group, as well as from a suitable combination of a resolvable balanced incomplete block design …

Implications Of Magnetic Evolution On Coronal Loop Thermal Variation Prior To Solar Flares, Kara L. Kniezewski

Theses and Dissertations

Solar flares are intense bursts of electromagnetic radiation, which occur due to a rapid destabilization and reconnection of the magnetic field. While flares are a magnetic phenomena, very little attention has been paid to thermal conditions in the corona prior to flare onset. This study serves as a follow-on to Kniezewski et al., 2024, where the EUV emission from coronal loops was observed to vary substantially and without any coherence between channels before 53 off-limb flares. These variations suggest multiple mechanisms within the coronal magnetic field are responsible for heating fluctuations. Here, the 3D magnetic field is modeled using a …

Investigation Of Neutron Inelastic Scatter Cross Sections On 16O, Molly A. Wakeling

Theses and Dissertations

Nuclear data underpin a number of applications across nuclear reactor design, medicine, astrophysics, nonproliferation, national security, and other related fields. However, data are conflicting or missing across the spectrum of isotopes and reactions, and theoretical calculations can only go so far to predict nuclear properties. A key reaction with incomplete data is neutron inelastic scatter on ¹⁶O, which reduces neutron energies and produces high-energy gamma rays that are often not taken into account in simulations of nuclear reactors, nuclear weapon detonations, nuclear fusion, and other areas. To fill these gaps, the Gamma-Energy Neutron-Energy Spectrometer for Inelastic Scattering, or GENESIS, …

Assessing The Feasibility Of Managed Aquifer Recharge For The United States Air Force, Daniel Hendrix

Theses and Dissertations

Water stress is becoming an increasing global issue, with 4 billion people (50% of the world’s population) experiencing water stress at least one month per year. By 2050, 60% of the world’s population and $70 trillion USD in global gross domestic product will be affected. This research analyzes 78 CONUS USAF installations to determine location-specific water stress and feasible Managed Aquifer Recharge (MAR) solutions. Although thousands of MAR projects have been implemented globally, active-duty USAF installations have yet to contribute to solving this growing issue. Important factors such as required subsurface conditions, physical limitations, design, cost, and regulatory constraints are …

Event-Based Camera Simulation And Neural Network Processing For Autonomous Aerial Refueling, Stephanie C. Hanson

Theses and Dissertations

Event-based cameras excel in dynamic environments, and do not face challenges like washout and motion blur, like a frame-based camera. This work describes the process used to collect the first EBS data collect for use in AAR, and develops an event simulator to generate synthetic training data for evaluating CNN architectures on asynchronous data. The three models compared are a traditional CNN, a YOLO-based CNN, and an asynchronous sparse CNN. The YOLO-based model achieved the best accuracy, while the sparse CNN, despite being less optimized, maintained an average IoU of 0.9. These results highlight the potential of asynchronous approaches for …

Heterogeneous Boid Swarm Performance Under Environmental And Neighbor Communication Link Variability, Jonathan C. Oxborrow

Theses and Dissertations

Artificial swarms are of growing interest in numerous fields and use cases. As their utilization increases drones and robots with different capabilities will be required to coordinate for task completion thus creating heterogeneous swarms. Swarm individuals generally communicate with all neighbors inside their sensor range generating a significant amount of message traffic. Previous research of a heterogeneous group in a non-physical environment has shown that restricting communication to only one neighbor of each different capability maintained performance. This work applies that finding to a heterogeneous boid swarm with the addition of varied environmental conditions. The swarm is comprised of three …

Analyzing Lf/Vlf Lightning Waveforms To Estimate D-Region Electron Density Profiles: Process, Application, And Comparison, William R. Smith

Theses and Dissertations

Lightning waveforms in the low frequency (LF; 30-300 kHz) and the very low frequency (VLF; 3-30 kHz) can be exploited to produce data-driven ionospheric Dregion electron density profile (EDP) estimates with significantly higher spatial and temporal coverage than previously available. The lightning waveforms used in this paper are signals detected in the LF/VLF of negative cloud-to-ground lightning by the Earth Networks Total Lightning Detection Network. Each waveform contains a ground wave and a time-delayed ionospheric reflection. The time delay between the ground wave and ionospheric reflection has previously been used to estimate a single specular reflection altitude, where LF/VLF emissions …

Forecasting Army Recruiting Mission Distribution, Maxwell A. Deihl

Theses and Dissertations

The Army’s recruiting landscape has changed markedly in recent years, raising questions about whether forecasting methods of Army contracts remain robust. This thesis recreates the presented models in Joshua McDonald’s 2015 thesis. It replicates and evaluates the models with updated data (2018–2023) to assess their current validity and compare them to novel alternative approaches, such as simpler regression models or neural networks. While the 2015 model remains a valuable baseline, results suggest that either refining its variables or adopting alternative methods can improve predictive accuracy and interpretability. Ultimately, the United States Army Recruiting Command has many options regarding how it …

Correlating Aerosol Morphology And Optical Properties With Image Blur: An Investigation Of Aerosol-Induced Image Degradation, Patricia A. Byrd

Theses and Dissertations

Small-angle scattering by relatively large cloud/fog droplets and ice crystals is known to degrade imagery. However, it is not well investigated how much of an impact aerosols, especially the prevalent anthropogenic fine/ultra-fine/coarse particles, have in image degradation. This thesis explores the contribution of aerosols to image blur but focuses on collecting field data with a relatively large variety of ambient aerosol characterization and optical instrumentation. Field experiments were conducted over six days, correlating aerosol measurements (particle counters and nephelometer) with image quality from a visible camera along a 450m path. Image blur was quantified using the Modulation Transfer Function (MTF), …

The Metaphysics Of Time Within Physics, Mohamed Ahmed

Theses and Dissertations

The starting point of this thesis is to shed some light on the metaphysical nature of time by reflecting on the physics of time. The aim of this approach is not to [dis]prove or defend a metaphysical position but rather to elucidate the metaphysical position that underlies [or is compatible with] our best scientific theories. This task will be demanding, not only because our best theories may carry different interpretations of their underlying temporal structure but also because there seems to be a conceptual conflict/incompatibility between the notion of time in relativity and quantum mechanics, which are the two major …

Fragmentation Functions For Light And Heavy Quarks In Simulated Proton-Proton Collisions, Nermin Kamal Sadoun

Theses and Dissertations

In the first microsecond after the Big Bang, the early universe is believed to have been in an excited state known as the Quark-Gluon Plasma (QGP) state, a state of free quarks and gluons. Conducted experiements, like Heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), have showed some evidences of the formation of this extreme states in the collisions. Jet quenching and elliptic flow are two phenomena that provide significant evidence for the creation of QGP and its distinctive characteristics. Although the major framework for studying QGP is still heavy-ion collisions, new research …

Tailor-Designed Oxalic Acid-Crosslinked Poly(Vinyl Alcohol)/Chitosan Biodegradable Films For Active Food Packaging Applications, Reem Hazem Fathy Anwar Elaasar

Theses and Dissertations

Food packaging plastic waste is posing great threats to ecosystems, human health, and the planet's overall sustainability; therefore, research has been directed towards the fabrication of biodegradable food packaging materials. In this study, active and biodegradable oxalic acid (OA) crosslinked poly(vinyl alcohol) (PVA)/chitosan (CS) composite films of different weight ratios were synthesized via the solvent casting technique and their food packaging properties were investigated. Owing to its water resistance and antibacterial superiority, the composite film with the ratio of OA chemically crosslinked PVA/CS 80:20 was elected to be coated with green tea extract (GTE) to ameliorate its antibacterial and antioxidant …

Adapting Biological Mechanisms Into Machine Learning Structures And Gradient Propagation, Hao Yu

Theses and Dissertations

As neuromorphic computing gains traction, researchers look for learning schemes that are more suitable for brain-like structures. Although many algorithms have been discovered, such as surrogate gradient or Spike Timing Dependent Plasticity, those algorithms are either unsuitable for on-chip training or not biologically aligned. The goal of this thesis is to discover a learning algorithm which is biologically aligned and suitable for on-chip training. Through the discoveries of our two papers, we are able to introduce the concepts of synaptic clefts and neurotransmitters into a common spiking neuron network. We also designed an error propagation method aligning with biology. With …

Hypergraph Association With Lie Algebra Of Upper Triangular Matrices And Its Application To Wireless Networks, Supriya S

Theses and Dissertations

A hypergraph is a generalized graph characterized by edges spanning more than one vertices describing multiple relationships among them. It provides a mathematical framework for comprehending and learning about a wide range of real-world challenges. On the other side, the theory of non-associative algebras, such as Jordan, Octonions, Malcev, and Lie, has found significant impetus in recent years. These structures proved intriguing from an algebraic standpoint; they generated novel concepts and approaches that aided in solving specific classic algebraic problems, also progressing towards application.

A preeminent observation that galvanizes this thesis is that hypergraph association is still unexplored in Lie …

A Robust Framework For Graph Construction In Vision Graph Neural Networks, Ismael Elsharkawi

Theses and Dissertations

In Computer Vision, the method of representing an image has a profound effect on the performance of a model. Traditionally speaking, an image is treated as a grid of pixels and can be processed via Convolution Neural Net- works (CNN). An image can also be treated as a sequence of patches. Vision Transformers and MLP-Mixers (Multi-Layer Perceptron Mixers) are two types of models that process an image as a sequence. A more generic representation than grids and sequences would be graphs. That is why Vision Graph Neural Network (ViG) construct a graph for an image and process the image as …

Sustainability Transformation For Healthcare Facilities Following Net Zero Model, Esraa Elmitainy

Theses and Dissertations

The healthcare industry is a field undergoing huge development. Focused on SDG 3 “Good Health and Well-being”, the healthcare industry, as the main health service provider, was marked by experts as a sector that should lead sustainable development by example. The current work aims to formulate a sustainability rating system for new and existing healthcare facilities to encourage the Egyptian healthcare industry to move towards sustainability according to net zero concepts. Additionally, the transition to net zero waste is investigated though experimental work to test the possibility of utilizing sterilized medical waste in cement-based bricks.

The rating system starts with …

The Influence Of The Un Watercourses Convention On The Development Of A Policy Design In The Nile River Basin, Zienab Ali Abdelhady

Theses and Dissertations

The adoption in 1997 of the United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UN Watercourses Convention or UNWC) marked a milestone in the codification and progressive development of international water law. Similarly, the signature in 2010 by the majority of the Nile Basin states of the Nile River Basin Cooperative Framework Agreement (CFA) was a major step towards a permanent legal and institutional framework as well as a significant shift from the currently applicable legal regime in the basin. The research concludes that the principles enshrined in the UNWC can assist future regional treaty …

Securing A Virtual Reality Classroom Using Unity, Okemute Samuel Idonor

Theses and Dissertations

This study examines how security features might be incorporated into a Unity created virtual reality (VR) classroom, with a particular emphasis on important concerns including user privacy, data security, and illegal access. The increasing usage of virtual reality (VR) technology in educational settings has made it crucial to ensure the security of these immersive systems, especially when it comes to safeguarding sensitive user data. Designing and implementing a secure VR classroom prototype that could successfully protect against common security concerns, such as unauthorized access and data breaches, was the main goal of this project. Multi-Factor Authentication (MFA), Role-Based Access Control …

Using Satellite Image Segmentation To Detect Trails, Jeremy Reynolds

Theses and Dissertations

This masters thesis proposes an innovative approach to satellite image segmentation by focusing on the detection and mapping of walking, hiking, and biking trails. The motivation behind this project comes from the underexplored area in segmentation techniques for trail identification and offers potential benefits for urban planning, environmental monitoring, and public health. The problem statement addresses the need for a model that can differentiate between various trail types and other natural or man-made elements. The project aims for efficiency and scalability in processing satellite imagery across different compute hardware. The work details several stages: researching existing segmentation techniques, specifically road …

Stability Of Lif Mirror Coatings On Space Telescopes At L2 Orbit, Devin M. Lewis

Theses and Dissertations

A team at Goddard Space Flight center has developed a coating of aluminum mirrors they term XeLiF. This coating has high ultraviolet reflection and improved environmental stability over similar LiF coatings. For these reasons, it is a potential candidate for the future Habitable Worlds Observatory (HWO) flagship space telescope mission. However, the stability of XeLiF at the planned L2 orbit of HWO has not been investigated. This study highlights the potential damage to XeLiF when irradiated by electrons that will be present at L2. This radiation will begin removing LiF after 6 years of exposure as well as start roughening …

Geospatial Machine Learning Approaches For Studying Urbanization Impact, Surface Reflectance Patterns, And Groundwater Health Risks, Bibhash Nath

Theses and Dissertations

Geospatial machine learning techniques have been used to study: the impact of urbanization on land use and land cover change, surface reflectance patterns in boreal regions, and groundwater health risks from arsenic in India. These studies combined spatial data, remote sensing, and predictive models to gain valuable insights for sustainable living and protecting human health.

Mechanism Of Napthenic Acid Binding To Dissolved Organic Matter, Clarissa Jules

Theses and Dissertations

The oil sands in Alberta, Canada are being destroyed by oil extraction because remediation methods have proven largely ineffective. One toxic byproduct of oil extraction is a family of cyclical surfactant organic acids known as naphthenic acids (NAs). They are toxic to aquatic life, including fish, frogs, and aquatic birds. It is suspected that NAs bind to humic acid, a major organic component of soil, in dissolved organic matter in natural water, making them difficult to remove by conventional remediation methods. This problem prompts the following question: what is the binding mechanism between NAs and humic acid when dissolved in …

Protein-Metal Interactions Of A-Synuclein And Bioactive Transition Metals Via Molecular Dynamics, Gonzalo R. Vazquez

Theses and Dissertations

Parkinson’s Disease (PD) is a neurodegenerative movement disorder which has been found to target the dopaminergic neurons of the substantia nigra. It is characterized by the formation of masses known as Lewy Bodies, formed by aggregates of the intrinsically disordered protein (IDP) -synuclein (asyn). Research suggests that alpha synuclein can undergo aggregation in the presence of heavy metals, which may accumulate in the body through a variety of mechanisms. To study how metals may play a role in wildtype (WT) asyn aggregation, MD simulation of the protein was performed in the presence of bioactive transition metals including Fe2+, Fe3+, Cu+, …

Electrochemical And Conformational Patterns Of S-Glycosides And The Synthesis Of Schistosoma Mansoni Antigens, Bhavesh Rajendra Deore

Theses and Dissertations

This thesis dives into two relevant fields in carbohydrate science: reactivity and conformation. We centered our attention on S-glycosides, a common class of glycosyl donors and glycomimetics, to study the influence exerted by the structural architecture over the conformational properties about flexible bonds and the reactivity towards electrochemical activation. Studying the conformational properties of sugars is key to understanding the molecular recognition mechanisms underlying their biological functions. Moreover, a well understanding of how the molecular components affect free rotation about bonds can be valuable information to design improved glycomimetic drug candidates. On the other hand, electrosynthesis is a promising application …

Synthesis And Characterization Of Novel Coumarin Derivatives, Jeanmeil M. Nestor

Theses and Dissertations

An optimized approach toward the synthesis of representative coumarin derivatives is described. In addition to standard heat application methods, microwave-assisted coupling has proven beneficial in generating the targeted molecular hybrids which will serve as key templates in the development of new drugs to address resistance and specificity challenges. The coumarin moiety is a fantastic scaffold for molecular hybridization and has gained much warranted attention due to its efficacy in anticancer, antibacterial, and antitumor activity. In this research, novel molecular hybrids of umbelliferone were synthesized and fully characterized as new potential players in the anticancer, antitumor and antibiotic race, as well …

Adsorption And Recovery Studies Of Cadmium And Lead Ions Using Biowaste Adsorbents From Aqueous Solutions, Liang Feng

Theses and Dissertations

The use of low-cost biowaste adsorbents for the removal of toxic metal ions from aqueous solutions offers significant environmental benefits and demonstrates strong potential. This study evaluated luffa peels and chamomile flowers as low-cost biosorbents for the adsorption and recovery of Cd2+ and Pb2+ ions in both batch and column modes. To enhance adsorption capacity, the biosorbents were treated with 0.4 M HNO3 or 0.4 M NaOH. Fourier transform infrared spectroscopy (FTIR) characterization showed that surface OH, C=O, CO and COO groups played a role in the adsorption process. Batch adsorption studies indicated an order of adsorption capacity as follows: …