Physical Sciences and Mathematics Commons^™

Monarch Science Observer, Volume 10, College Of Sciences, Old Dominion University

College of Sciences Newsletter

Summer 2021 issue of Monarch Science Observer, ODU College of Sciences Newsletter.

A Look Into Increasing The Number Of Veterans And Former Government Employees Converting To Career And Technical Cybersecurity Teachers, Vukica M. Jovanovic, Michael Anthony Crespo, Drew E. Brown, Deborah Marshall, Otilia Popescu, Murat Kuzlu, Petros J. Katsioloudis, Linda Vahala

Engineering Technology Faculty Publications

The current state of technology with recent explosions in the digital processing of paperwork, computer networking use, and online and virtual approaches to areas, which until very recently had traditional and non-computerized ways of operating, led to a steady increase in the demand for jobs in the area of computer science and cybersecurity. The education system, the pipeline for the incoming workforce, needs to keep up with this tremendous pace in technology and the job market. The current K-12 school system has been extensively challenged to fill out necessary positions in order to address the increasing need for programs that …

Numerical Calculation Of Losses Of Trapped Vortices Under Strong Rf Meissner Current And Dc Superheating Field In Type Ii Superconductors, Walive Pathiranage Manula Randhika Pathirana

Physics Theses & Dissertations

Research on the vortex dynamics and enhancing of superheating field in superconductors has attracted much attention in accelerator physics community to develop next-generation high-performance accelerator cavities. However, the extreme dynamics of curvilinear elastic vortices driven by very strong currents close to the depairing limit or superheating field of a superconductor with a nanostructured surface has not been well understood. We calculated the superheating field H_sh and critical momentum kc characterizing the wavelength of the instability λ_m of the Meissner state to flux penetration by solving numerically the Ginzburg-Landau equations. A bulk superconductor, superconductor with the inhomogeneous surface disorder …

J/Ψ Photoproduction Near Threshold With Clas12, Joseph Newton

Physics Theses & Dissertations

The structure of the proton is comprised of quarks and a sea of gluons. A mechanism that can extract the characteristics of the hidden-color correlations of the nuclear wavefunction is the production of charm near threshold. Due to the fact that momentum transfer is large near threshold in the production of J/ψ , all three valence quarks must act coherently to ex- change energy for the reaction to occur. Models have been developed to predict the nature of J/ψ photoproduction at these specific energies. These include production mechanisms with the two-gluon and three-gluon exchanges. The transferred momentum dependence of the …

Quasiclassical Computations Of Compton-Scattered Spectra, Erik Scott Johnson

Physics Theses & Dissertations

Quality X-ray sources are crucial to fundamental physics research, medical radiology, humanities research, and materials science. While synchrotron radiation (SR) facilities produce the state-of-the- art emissions with respect to brilliance and frequency tunability, the great expense required to build, maintain, and operate these structures greatly limits their accessibility to researchers. Much of the research conducted at SR facilities, however, may be conducted with inverse Compton sources (ICS). Accelerator-based Compton scattering light sources generate high-energy, high-brilliance emissions. Compton scattering is the process by which a photon scatters off an electron. ICS offer an affordable, in-lab alternative to SR facilities. Even though …

Development And Applications Of Adjoint-Based Aerodynamic And Aeroacoustic Multidisciplinary Optimization For Rotorcraft, Ramiz Omur Icke

Mechanical & Aerospace Engineering Theses & Dissertations

Urban Air Mobility (UAM) is one of the most popular proposed solutions for alleviating traffic problems in populated areas. In this context, the proposed types of vehicles mainly consist of rotors and propellers powered by electric motors. However, those rotary-wing components can contribute excessively to noise generation. Therefore, a significant noise concern emerges due to urban air vehicles in or around residential areas. Reducing noise emitted by air vehicles is critically important to improve public acceptance of such vehicles for operations in densely populated areas.

Two main objectives of the present dissertation are: (1) to expand the multidisciplinary optimization to …

A Digital One Degree Of Freedom Model Of An Electromagnetic Position Sensor, Michelle Elizabeth Weinmann

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of this project was to improve an existing system currently in use by NASA Langley Research Center (LaRC). The 6-inch Magnetic Suspension and Balance System (MSBS) built at MIT is operational with control in three degrees of freedom, with two additional degrees of freedom exhibiting passive stability. The means for measuring model displacement within the magnetic environment is an Electromagnetic Position Sensor (EPS), consisting of excitation coils at 20 kHz and multiple sets of pickup coils. The pickup coil voltages are proportional to model displacement in each degree of freedom. However, the EPS electronic signal processing system is …

Deep Learning Approaches For Seagrass Detection In Multispectral Imagery, Kazi Aminul Islam

Electrical & Computer Engineering Theses & Dissertations

Seagrass forms the basis for critically important marine ecosystems. Seagrass is an important factor to balance marine ecological systems, and it is of great interest to monitor its distribution in different parts of the world. Remote sensing imagery is considered as an effective data modality based on which seagrass monitoring and quantification can be performed remotely. Traditionally, researchers utilized multispectral satellite images to map seagrass manually. Automatic machine learning techniques, especially deep learning algorithms, recently achieved state-of-the-art performances in many computer vision applications. This dissertation presents a set of deep learning models for seagrass detection in multispectral satellite images. It …

Riverology: Promoting Stewardship Of Rivers Through Youth Participation In Science And Art, Robin R. Dunbar

Institute for the Humanities Theses

This project focuses on mentoring children to help reduce marine debris in their local river by implementing one of ten lessons from an inquiry-based Riverology curriculum to empower youth voice, increase geo-literacy, and spatial thinking. Eighteen participants aged seven and eight, piloted Riverology Lesson 2: What Do I Know or Imagine about the Elizabeth River? that includes six steps: inquire, visualize, draw, share, act, and reflect. The children were asked to make drawings before and after viewing an Elizabeth River Story Map presentation (Dunbar, 2021a). The drawings were then compared to see if the participants included marine debris, stewardship solutions, …

Wiener-Fliess Composition Of Formal Power Series: Additive Static Feedback And Shuffle Rational Series, Subbarao Venkatesh Guggilam

Electrical & Computer Engineering Theses & Dissertations

The problem statement for this dissertation is two-fold. The first problem considered is when does a Chen-Fliess series in an additive static feedback connection with a formal static map yield a closed-loop system with a Chen-Fliess series expansion? This work proves that such a closed-loop system always has a Chen-Fliess series representation. Furthermore, an algorithm based on the Hopf algebras for the shuffle group and the dynamic output feedback group is designed to compute the generating series of the closed-loop system. It is proved that the additive static feedback connection preserves local convergence and relative degree, but a counterexample shows …

Quantifying Cyber Risk By Integrating Attack Graph And Impact Graph, Omer F. Keskin

Engineering Management & Systems Engineering Theses & Dissertations

Being a relatively new risk source, models to quantify cyber risks are not well developed; therefore, cyber risk management in most businesses depends on qualitative assessments. With the increase in the economic consequences of cyber incidents, the importance of quantifying cyber risks has increased. Cyber risk quantification is also needed to establish communication among decision-makers of different levels of an enterprise, from technical personnel to top management.

The goal of this research is to build a probabilistic cybersecurity risk analysis model that relates attack propagation with impact propagation through internal dependencies and allows temporal analysis.

The contributions of the developed …

Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan

Chemistry & Biochemistry Theses & Dissertations

Thyroid hormones (THs) in mammalian tissues are crucial for development and maintaining metabolic homeostasis. Iodothyronine deiodinases (Dios) remove iodines from THs by a selenocysteine (Sec) residue, which either activates or inactivates them. Halogen bonding (XB) has been proposed to describe the interaction between the Se and I atoms of the T4-Dio complex. Disruption of TH homeostasis by xenobiotics, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) can cause deleterious effects on the endocrine system. Experimental studies have indicated that PBDEs and PCBs could disrupt TH homeostasis by inhibiting Dio through XB formation. However, no current quantitative study exists …

Improvement Of Biochar Through Ozonization And Biosafety Of Genetically Engineered Cyanobacteria, Oumar Sacko

Chemistry & Biochemistry Theses & Dissertations

Through the innovative technique of biochar post-production surface oxygenation by ozonization, we were able to improve certain properties of biochar. In project one, the incubation of an insoluble phosphate rock material (hydroxyapatite) with the wet ozonized pine 400 biochar and its filtrate resulted in a solubilization of 80 times more phosphate from hydroxyapatite (569.0 mg/L ± 6.4) compared to the pure water-hydroxyapatite control (7.2 mg/L ± 0.3). The ozonized biochar may provide a new possible way to unlock the phosphorus from insoluble phosphate mineral phases. The cation exchange capacity (CEC) is a key property of biochar when used as a …

Move: Mobile Observers Variants And Extensions, Ryan Florin

Computer Science Theses & Dissertations

Traffic state estimation is a fundamental task of Intelligent Transportation Systems. Recent advances in sensor technology and emerging computer and vehicular communications paradigms have brought the task of estimating traffic state parameters in real-time within reach.

This has led to the main research question of this thesis: Can a vehicle accurately estimate traffic parameters using onboard resources shared through CV technology in a lightweight manner without utilizing centralized or roadside infrastructure?

In 1954 Wardrop and Charlesworth proposed the Moving Observer method to measure traffic parameters based on an observed number of vehicle passes. We start by proposing methods for detecting …

Physiological And Molecular Responses Of Eurythermal And Stenothermal Populations Of Zostera Marina L (Eelgrass) To Climate Change, Carmen C. Zayas-Santiago

OES Theses and Dissertations

As CO₂ levels in Earth’s atmosphere and oceans steadily rise, varying organismal responses may produce ecological losers and winners. Increased ocean CO₂ can enhance seagrass productivity and thermal tolerance, providing some compensation for climate warming. However, the consistency of this CO₂ effect across populations of cosmopolitan species such as Zostera marina L. (eelgrass) remains largely unknown. This study analyzed whole-plant performance metabolic profiles and gene expression patterns of distinct eelgrass populations in response to CO₂ enrichment. Populations were transplanted from Nisqually Landing and Dumas Bay, two cold water environments in Puget Sound, WA (USA) that rarely …

Examining Melt Pond Dynamics And Light Availability In The Arctic Ocean Via High Resolution Satellite Imagery, Austin Wesley Abbott

OES Theses and Dissertations

As the Arctic experiences consequences of climate change, a shift from thicker, multi-year ice to thinner, first-year ice has been observed. First-year ice is prone to extensive pools of meltwater (“melt ponds”) forming on its surface, which enhance light transmission to the ocean. Changes in the timing and distribution of melt pond formation and associated increases in under-ice light availability are the primary drivers for seasonal progression of water column primary production and warming. Observations of melt pond development and distribution require meter scale resolution and have traditionally been limited to airborne images. However, recent advances in high spatial resolution …

The Development Of Novel Carbohydrate-Based Gelators And Their Applications As Advanced Soft Materials, Joedian Morris

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are attractive molecules that have been explored extensively due to their practical applications in many disciplines. These small molecules self-assemble forming solid-like gels via three-dimensional cross-linked networks with the solvent as the key component within the matrix. Carbohydrate-based LMWGs are small molecules that can form solid-like gels in water, organic solvents, and aqueous solutions. They have great potential to be utilized in different applications because carbohydrates are biocompatible and can be made from easily accessible and renewable resources. Designing gelators is still a challenge within the field, even though researchers have developed tools to predict …

Towards An Integrated Assessment Of Sea-Level Observations Along The U.S. Atlantic Coast, Brett A. Buzzanga

OES Theses and Dissertations

Sea levels are rising globally due to anthropogenic climate change. However, local sea levels that impact coastal ecosystems often differ from the global trend, sometimes by a factor of two or more. Improved understanding of this regional variability provides insights into geophysical processes and has implications for coastal communities developing resilience to ongoing sea-level rise. This dissertation conducts an investigation of sea level and its contributing processes at multiple spatial scales. Focusing on primarily interannual time-scales and data-driven approaches, new data sources and technologies are utilized to reduce current uncertainties.

First, sea-level trends are assessed over the global ocean and …

Improving Collection Understanding For Web Archives With Storytelling: Shining Light Into Dark And Stormy Archives, Shawn M. Jones

Computer Science Theses & Dissertations

Collections are the tools that people use to make sense of an ever-increasing number of archived web pages. As collections themselves grow, we need tools to make sense of them. Tools that work on the general web, like search engines, are not a good fit for these collections because search engines do not currently represent multiple document versions well. Web archive collections are vast, some containing hundreds of thousands of documents. Thousands of collections exist, many of which cover the same topic. Few collections include standardized metadata. Too many documents from too many collections with insufficient metadata makes collection understanding …

Molecular Dynamics Simulations Of Ion Transport Through Electrically Stressed Biological Membranes, Federica Castellani

Biomedical Engineering Theses & Dissertations

The cell membrane is a selectively permeable barrier that controls the transport of ions, molecules, and other materials into and out of a cell. The manipulation of the cell membrane permeability is the basis for several biotechnological and biomedical applications, including electroporation. Electroporation (or electropermeabilization) occurs when the application of an external electric pulse causes water intrusion into the membrane interior and the formation of conductive transmembrane electropores. These electropores allow drugs, genetic material, and other normally impermeant molecules to enter a cell. Despite years of study, the complex mechanisms underlying this process are still not well understood. Molecular dynamics …

Codar's Surface Flow At The Mouth Of The Chesapeake Bay: Relation To Bay's And Atlantic's Forcing, Shelby Kathryn Henderson

OES Theses and Dissertations

Surface currents in the lower Chesapeake Bay (CB) observed with land-based high-frequency radar antennas, or Coastal Ocean Dynamics Application Radar (CODAR), produce hourly 2D maps of current velocities used for search and rescue, pollution tracking, and fishing operations. This study analyzes the correlations between a 9-year record of surface currents measured by CODAR to coastal sea level, local wind forcing, river discharge into CB, and water transport through the Florida Straits, representing the Gulf Stream’s control on sea level along the U.S. mid-Atlantic coast. The goal of this study is to find ways to use CODAR data to detect and …

A Unified Framework For Parallel Anisotropic Mesh Adaptation, Christos Tsolakis

Computer Science Theses & Dissertations

Finite-element methods are a critical component of the design and analysis procedures of many (bio-)engineering applications. Mesh adaptation is one of the most crucial components since it discretizes the physics of the application at a relatively low cost to the solver. Highly scalable parallel mesh adaptation methods for High-Performance Computing (HPC) are essential to meet the ever-growing demand for higher fidelity simulations. Moreover, the continuous growth of the complexity of the HPC systems requires a systematic approach to exploit their full potential. Anisotropic mesh adaptation captures features of the solution at multiple scales while, minimizing the required number of elements. …

Methods For Detecting Floodwater On Roadways From Ground Level Images, Cem Sazara

Computational Modeling & Simulation Engineering Theses & Dissertations

Recent research and statistics show that the frequency of flooding in the world has been increasing and impacting flood-prone communities severely. This natural disaster causes significant damages to human life and properties, inundates roads, overwhelms drainage systems, and disrupts essential services and economic activities. The focus of this dissertation is to use machine learning methods to automatically detect floodwater in images from ground level in support of the frequently impacted communities. The ground level images can be retrieved from multiple sources, including the ones that are taken by mobile phone cameras as communities record the state of their flooded streets. …

Rainfall-Runoff Mechanisms And Flood Mitigation In A Coastal Watershed With Numerous Wetlands And Ponds, Homa Jalaeian Taghadomi

Civil & Environmental Engineering Theses & Dissertations

This study analyzed mechanisms of flooding in Blackwater River Watershed, located in coastal Virginia and hydraulically connected with mid-Atlantic Ocean. The analysis was based on the examination and simulation of the rainfall-runoff relationship, and such an analysis is very important for conventional water resource management and dealing with hydrologic extremes (e.g., floods and droughts, as well as ecological and pollution discharges). The rainfall-runoff relationship is a quantitative description of the hydrologic cycle, a dynamic process that can be interactively influenced by various factors, namely climate, topography, soils, land use and land cover, and land management practice.

In the past 60 …

High-Order Positivity-Preserving L2-Stable Spectral Collocation Schemes For The 3-D Compressible Navier-Stokes Equations, Johnathon Keith Upperman

Mathematics & Statistics Theses & Dissertations

High-order entropy stable schemes are a popular method used in simulations with the compressible Euler and Navier-Stokes equations. The strength of these methods is that they formally satisfy a discrete entropy inequality which can be used to guarantee L₂ stability of the numerical solution. However, a fundamental assumption that is explicitly or implicitly used in all entropy stability proofs available in the literature for the compressible Euler and Navier-Stokes equations is that the thermodynamic variables (e.g., density and temperature) are strictly positive in the entire space{time domain considered. Without this assumption, any entropy stability proof for a numerical scheme …

Finite Difference Schemes For Integral Equations With Minimal Regularity Requirements, Wesley Cameron Davis

Mathematics & Statistics Theses & Dissertations

Volterra integral equations arise in a variety of applications in modern physics and engineering, namely in interactions that contain a memory term. Classical formulations of these problems are largely inflexible when considering non-homogeneous media, which can be problematic when considering long term interactions of real-world applications. The use of fractional derivative and integral terms naturally relax these restrictions in a natural way to consider these problems in a more general setting. One major drawback to the use of fractional derivatives and integrals in modeling is the regularity requirement for functions, where we can no longer assume that functions are as …

Electrohydrodynamic Simulations Of Capsule Deformation Using A Dual Time-Stepping Lattice Boltzmann Scheme, Charles Leland Armstrong

Mathematics & Statistics Theses & Dissertations

Capsules are fluid-filled, elastic membranes that serve as a useful model for synthetic and biological membranes. One prominent application of capsules is their use in modeling the response of red blood cells to external forces. These models can be used to study the cell’s material properties and can also assist in the development of diagnostic equipment. In this work we develop a three dimensional model for numerical simulations of red blood cells under the combined influence of hydrodynamic and electrical forces. The red blood cell is modeled as a biconcave-shaped capsule suspended in an ambient fluid domain. Cell deformation occurs …

Odu Professor Examines An Overlooked Source Of Coastal Water Quality, Tiffany Whitfield

News Items

No abstract provided.

Pediatric Asthma – Another Negative Outcome Of Recurrent Flooding, Odu Researchers Find, News @ Odu

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No abstract provided.

Odu-Led Study Published In Nature Climate Change, Tiffany Whitfield

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No abstract provided.