Digital Commons Network^™

Studies Of Flowfields And Dynamic Stability Characteristics Of A Quadrotor, Engin Baris

Mechanical & Aerospace Engineering Theses & Dissertations

Electric multirotor air vehicles have become a pervasive technology and research topic in industry, academia, and daily life, and small quadrotors are one of the most preferred designs in the multirotor marketplace. However, the configuration of the quadrotors makes aerodynamic interaction effects one of the key factors of the vehicle performance in both hover and non-axial forward flight conditions.

In the present work, aerodynamic characteristics of the cross-configured small quadrotor in hover, edgewise, and maneuvering flight modes were investigated in detail by performing static and dynamic wind tunnel tests at various RPM levels, wind speeds, pitch and yaw angles, and …

Do Microplastics, Vibrio Bacteria, And Warming Water Temperatures Cause Disease In The Northern Star Coral, Astrangia Poculata?, Heather Leigh Sheffey

OES Theses and Dissertations

As marine plastic pollution increases, it becomes imperative to study the effects of microplastics on marine fauna. Marine plastic debris is a vector for disease to marine invertebrates (Lamb et al., 2018; Rotjan et al., 2019). In this context, studies have shown Astrangia poculata will consume microplastics as they do their normal food (Allen et al, 2017; Rotjan et al., 2019). Further, with temperatures increasing worldwide, there is a concern the virulence of disease-causing bacteria will increase (Vezzulli et al., 2015). In a series of manipulative laboratory experiments, this study quantified changes in respiration rates and visual health of Astrangia …

Considering Equity In Infrastructure Planning Processes And Outcomes For Coastal Resilience, Wie Yusuf, Marina Saitgalina, Tom Allen, Nicole S. Hutton, Jennifer L. Whytlaw, Joshua Behr

School of Public Service Faculty Publications

No abstract provided.

Public School Superintendents In Virginia: Innovating In The Educational Context, Daniel Firing Keever

Educational Leadership & Workforce Development Theses & Dissertations

This research study, using institutional theory as a framework, examines the role of superintendents in promoting and impacting innovation in Virginia's public schools. The study engaged fourteen current Virginia superintendents in semi-structured interviews, exploring their perspectives on fostering an innovative culture within their school districts. Three primary themes emerged from the research: defining innovation, the role of superintendents in leading innovation, and the challenges and barriers to innovation. Generally, the findings highlight that innovation fundamentally involves thinking differently, finding creative solutions, and bringing about meaningful organizational improvements. The study emphasizes that innovation is essential for adapting to the evolving needs …

The Implications Of Dual Enrollment Participation On Black/African American Students’ Success, Yousef Abraham

Educational Leadership & Workforce Development Theses & Dissertations

This dissertation presents a thorough investigation into the impact of dual enrollment programs on postsecondary achievement among students who identify as Black/African American. Dual enrollment initiatives have gained significant attention in recent years as a promising approach to enhance students' readiness for higher education and facilitate smoother transitions to college. This research seeks to provide valuable insights into the effectiveness and implications of such programs, shedding light on their potential to improve postsecondary outcomes for Black/African American students. This study also acknowledges inherent limitations and delves into potential practical applications of the research outcomes, exploring how educators and policymakers can …

Pulsed Electric Field Ablation: Mechanisms Of Differential Cell Sensitivity And Methods To Mitigate Neuromuscular Excitation, Emily Gudvangen

Biomedical Engineering Theses & Dissertations

Ablation therapies aim to destroy tumors while maintaining minimal damage to surrounding healthy tissue. Pulsed electric field (PEF) ablation targets the cell membrane during the destruction of tissues, which consequently spares extracellular structures such as ducts and blood vessels, leaving the framework for tissue regeneration. However, the utility of PEF is limited by neuromuscular excitation, causing pain and involuntary muscle contraction. To identify PEF protocols that efficiently ablate tissue while minimizing neuromuscular stimulation, various PEF protocols differing in pulse duration, shape, and repetition rate were tested. The ratio of cell death and nerve excitation thresholds, which determines the range of …

A Mindful Search For Basic Writing Identities: Constellating Contemplative Classroom Pedagogies, Classroom Community Circles, And Critical Discourse Analysis In A Cultural Rhetorics Ecology, Elizabeth Edwards Weems

English Theses & Dissertations

Many Basic Writing students have stories which are informed by traumas, othering, and marginalization. Finding pedagogies which address students’ stories, in addition to meeting academic goals, is crucial. Sometimes, students question how improving their reading and writing skills can help them navigate other areas of their education and experiences, especially their lives outside of academia. I have worked to create a kairotic pedagogy which invites students to read and write ‘the word and the world’ (Freire, 1970; 1988). Using Contemplative Classroom Pedagogies, I attempted to follow Freire’s (1992) call to make “teaching a creative act, a critical act, and not …

Machine Learning Approach To Activity Categorization In Young Adults Using Biomechanical Metrics, Nathan Q. C. Holland

Mechanical & Aerospace Engineering Theses & Dissertations

Inactive adults often have decreased musculoskeletal health and increased risk factors for chronic diseases. However, there is limited data linking biomechanical measurements of generally healthy young adults to their physical activity levels assessed through questionnaires. Commonly used data collection methods in biomechanics for assessing musculoskeletal health include but are not limited to muscle quality (measured as echo intensity when using ultrasound), isokinetic (i.e., dynamic) muscle strength, muscle activations, and functional movement assessments using motion capture systems. These assessments can be time consuming for both data collection and processing. Therefore, understanding if all biomechanical assessments are necessary to classify the activity …

Detecting Malware With Securedeep Accelerator Via Processor Side-Channel Fingerprinting For Internet Of Things, Zhuoran Li

Computer Science Theses & Dissertations

Over the past few years, there has been a substantial increase in cyberattacks targeting Internet of Things (IoT) devices, encompassing threats like botnets, ransomware, trojans, etc. Designing an effective solution for malware detection in IoT devices is particularly challenging due to their inherent limited resources and diverse architectures. Conventional malware detection methods, relying on large servers to deploy such as signature-based detection, prove impractical due to the resource constraints of IoT devices. Furthermore, the newly evolved malware variants have intensified this dilemma, such as malware exhibiting advanced stealthy behaviors or exploiting zero-day vulnerabilities. Therefore addressing this critical issue requires not …

Lithium Extraction From Aqueous Solution Using Magnesium Doped Lithium Ion-Sieve Composite, Ujjwal Pokharel

Civil & Environmental Engineering Theses & Dissertations

This study focused on the development of a magnesium doped ion-sieve composite to extract lithium from an aqueous solution using adsorption process. The extraction process will provide a sustainable alternative to the currently practiced solar evaporation/concentration method which is very slow (takes 24 months) and water intensive. Currently, most of the lithium in the world comes from the mining of lithium or from the evaporative extraction process from the brine. Additionally, the Salton Sea area geothermal brines are recognized as potentially important domestic sources of lithium. Lithium concentration in geothermal brines from the Salton Sea area is reported to be …

Deep-Learning-Based Classification Of Digitally Modulated Signals, John A. Snoap

Electrical & Computer Engineering Theses & Dissertations

This dissertation presents several novel deep-learning (DL)-based approaches for classifying digitally modulated signals, one method of which involves the use of capsule networks (CAPs) together with cyclic cumulant (CC) features of the signals. These were blindly estimated using cyclostationary signal processing (CSP) and were then input into the CAP for training and classification. The classification performance and the generalization abilities of the proposed approach were tested using two distinct datasets that contained the same types of digitally modulated signals but had distinct generation parameters. The results showed that the classification of digitally modulated signals using CAPs and CCs proposed in …

A New Method To Determine The Posterior Distribution Of Coefficient Alpha, John Mart V. Delosreyes

Psychology Theses & Dissertations

There is a focus within the behavioral/social sciences on non-physical, psychological constructs (i.e., constructs). These constructs are indirectly measured using measurement instruments that consist of questions that capture the manifestations of these constructs. The indirect nature of measuring constructs results in a need of ensuring that measurement instruments are reliable. The most popular statistic used to estimate reliability is coefficient alpha as it is easy to compute and has properties that make it desirable to use. Coefficient alpha’s popularity has resulted in a wide breadth of research into its qualities. Notably, research about coefficient alpha’s distribution has led to developments …

Fabrication Of Smooth Sac305 Thin Films Via Magnetron Sputtering And Evaluations Of Microstructure, Creep, And Electrical Resistivity, Manish Ojha

Mechanical & Aerospace Engineering Theses & Dissertations

SAC305 (96.5%Sn-3%Ag-0.5%Cu) is the leading alternative to the traditional Sn-Pb solder eutectic alloy owing to its low melting temperature, better compatibility with other components, and excellent mechanical/structural properties. In the realm of modern electronics, where devices are increasingly miniaturized, the design and characterization of thin solder joints become paramount. The orientation and size of the grains within the solder can influence its ability to withstand mechanical stresses. However, research on SAC thin films remains sparse, and these films present unique challenges and characteristics compared to their bulk counterparts, influenced by factors like interfaces, stresses, thickness, microstructure, and the nature of …

Structural Insights Into The Cl-Par-4 Protein: Ionic Requirements, Conformational Transitions, And Interaction With Cisplatin, Krishna Kumar Raut

Chemistry & Biochemistry Theses & Dissertations

Cancer continues to be the leading global cause of death, with challenges in early diagnosis, drug resistance, non-specific drug targeting, and cancer recurrence and metastasis posing formidable obstacles in cancer therapy. In this context, Prostate Apoptosis Response-4 (Par-4), a pro-apoptotic tumor suppressor protein, emerged as a promising therapeutic target due to its ability to selectively induce apoptosis in cancer cells, thereby minimizing the drug-associated adverse effects. However, a comprehensive understanding of the structural features of Par-4, specifically the caspase-cleaved fragment (cl-Par-4), is crucial for therapeutic advancements.

This dissertation investigated the effects of various ions, both monovalent and divalent, on the …

Faster, Cheaper, And Better Cfd: A Case For Machine Learning To Augment Reynolds-Averaged Navier-Stokes, John Peter Romano Ii

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, the field of machine learning (ML) has made significant advances, particularly through applying deep learning (DL) algorithms and artificial intelligence (AI). The literature shows several ways that ML may enhance the power of computational fluid dynamics (CFD) to improve its solution accuracy, reduce the needed computational resources and reduce overall simulation cost. ML techniques have also expanded the understanding of underlying flow physics and improved data capture from experimental fluid dynamics.

This dissertation presents an in-depth literature review and discusses ways the field of fluid dynamics has leveraged ML modeling to date. The author selects and describes …

Framework For Implementing Advanced Radar Plotting Aid Capability For Small Maritime Vessels, Jason Stark Harris

Electrical & Computer Engineering Theses & Dissertations

Every year in the United States many people are killed or injured when maritime vessels collide with other vessels or fixed objects. According to the United States Coast Guard, the top contributing factors to these collisions are operator inattention, operator inexperience and an improper lookout. Larger commercial vessels are required to have RADAR systems which support Automatic RADAR Plotting Aid (ARPA) which can automatically detect collisions and alert an operator to change course. These systems can be very expensive which put them out of reach of the average recreational boater. It is however possible to implement a low cost ARPA …

Using Reciprocal Teaching Strategies To Improve Reading Comprehension For English As A Second Language Students With Learning Disabilities, Hana M. Almohamadi

Theses and Dissertations in Early Childhood Education

Students who have problems comprehending textual material tend to experience failing grades, peer rejection, and even social isolation. Furthermore, students with poor reading comprehension demonstrate poor academic performance in all subjects, not due to difficulty in learning specific subject content (i.e., math, history, etc.), but rather their inability to comprehend reading passages related to that subject knowledge. Reciprocal teaching (RT) is an effective tool for teaching children with Learning Disabilities (LD) to improve their reading comprehension abilities. These multiple cognitive strategies can meet the needs of many students in terms of more deliberate, directed, and self-regulated learning through students’ interaction …

Always Reppin' Padua: An Examination Of Campanilismo In The Works Of Andrea Mantegna, Sarah Kathryn Suddith Gorman

Institute for the Humanities Theses

The Paduan painter Andrea Mantegna (1431 – 1506) was one of the most innovative and influential artists of the Italian Renaissance. His works have been the focus of numerous studies often focusing on his many connections within the city of Padua, his training under Francesco Squarcione (1397 – 1468), and other artists he encountered there during his youth. None, however, have investigated evidence of Paduan campanilismo within his body of work. Campanilismo is an important aspect of Italian identity, where individuals feel a strong sense of belonging, identity, and pride to the location of their birth, more powerful even than …

Optics Studies For Multipass Energy Recovery At Cebaf: Er@Cebaf, Isurumali Neththikumara

Physics Theses & Dissertations

Energy recovery linacs (ERLs), focus on recycling the kinetic energy of electron beam for the purpose of accelerating a newly injected beam within the same accelerating structure. The rising developments in the super conducting radio frequency technology, ERL technology has achieved several noteworthy milestones over the past few decades. In year 2003, Jefferson Lab has successfully demonstrated a single pass energy recovery at the CEBAF accelerator. Furthermore, they conducted successful experiments with IR-FEL demo and upgrades, as well as the UV FEL driver. This multi-pass, multi-GeV range energy recovery demonstration proposed to be carried out at CEBAF accelerator at Jefferson …

Organic Carbon Decay Mediated By Mesopelagic Microbial Communities, Noah Jonathan Craft

OES Theses and Dissertations

Substantial remineralization of organic carbon occurs in the mesopelagic zone (i.e., the biological pump), the efficiency of which is responsible for the oceans’ capacity to store carbon originally derived from the atmosphere. To better understand how a substrate’s composition influences its degradation by mesopelagic microbial communities, we added treatments made of live algal cells, dead particulate organic carbon and dissolved organic carbon from ¹⁴C-labeled algal cultures to mesopelagic water collected in-situ. Each incubation took place in the laboratory over a period of months, during which PO¹⁴C, DO¹⁴C, ATP, prokaryote abundances and biochemical fractions were measured. …

The Effects Of Self-Regulated Learning On Community College Students Metacognition, Motivation And Achievement In Geoscience Courses, Melani A. Loney

Educational Leadership & Workforce Development Theses & Dissertations

This study investigated the impact of training in self-regulated learning on community college, geoscience students’ achievement, metacognition, time management, and science motivation scales. The study also investigated the impact of SRL training on these outcomes as a function of gender and ethnicity. During the Fall of 2022, 70 community college geoscience students from 9 different classes participated in the study. The classes were bifurcated with one half of the students in each class randomly assigned to the SRL treatment and the other half to the control condition. Each week, for 10 weeks during the semester, students in the treatment group …

An Effective Model For Dynamic Properties Of Local Soils And Their Influence On Seismic Response Of A Typical Reinforced Concrete Building, Kaveh Zehtab

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents an effective model to determine the dynamic properties of local soils and their impact on the seismic response of a typical mid-height reinforced concrete building. The results of the study suggest that the use of global models and empirical relationships for the dynamic properties of soils may not consider the effects of unique stress conditions on the cyclic response of the foundation soil. The study also investigates the seismic response of a site in central Adapazarı, Turkey, where four- to seven-story buildings suffered significant damage during the 1999 Kocaeli earthquake. A new model is presented that combines …

Tracing And Segmentation Of Molecular Patterns In 3-Dimensional Cryo-Et/Em Density Maps Through Algorithmic Image Processing And Deep Learning-Based Techniques, Salim Sazzed

Computer Science Theses & Dissertations

Understanding the structures of biological macromolecules is highly important as they are closely associated with cellular functionalities. Comprehending the precise organization of actin filaments is crucial because they form the dynamic cytoskeleton, which offers structural support to cells and connects the cell’s interior with its surroundings. However, determining the precise organization of actin filaments is challenging due to the poor quality of cryo-electron tomography (cryo-ET) images, which suffer from low signal-to-noise (SNR) ratios and the presence of missing wedge, as well as diverse shape characteristics of actin filaments. To address these formidable challenges, the primary component of this dissertation focuses …

Monarch Science Observer, Volume 17, College Of Sciences, Old Dominion University

College of Sciences Newsletter

Fall 2023, issue of Monarch Science Observer, ODU Colleges of Sciences Newsletter.

Supporting Multilingual Learners’ Reading Competence: A Multiple Case Study Of Teachers’ Instruction And Student Learning And Motivation, Melissa A. Gallagher, Jori S. Beck, Erin M. Ramirez, Ana Taboada Barber, Michelle M. Buehl

Teaching & Learning Faculty Publications

Supporting students’ reading competence (i.e., their comprehension and vocabulary) is complex, particularly when working with multilingual learners, and involves implementing instructional practices to support their behavioral engagement in reading as well as their reading motivation. The purpose of this mixed methods case study was to examine changes in multilingual learners’ reading comprehension, academic vocabulary, reading engagement, and reading motivation after participating in a 7-week intervention called United States History for Engaged Reading (USHER) and then examine qualitative data to explain why these changes may have occurred. We found changes in the reading comprehension of MLs across all four teachers’ classes, …

A Unit-Load Approach For Reliability-Based Design Optimization Of Linear Structures Under Random Loads And Boundary Conditions, Robert James Haupin, Gene Jean-Win Hou

Mechanical & Aerospace Engineering Faculty Publications

The low order Taylor’s series expansion was employed in this study to estimate the reliability indices of the failure criteria for reliability-based design optimization of a linear static structure subjected to random loads and boundary conditions. By taking the advantage of the linear superposition principle, only a few analyses of the structure subjected to unit-loads are needed through the entire optimization process to produce acceptable results. Two structural examples are presented in this study to illustrate the effectiveness of the proposed approach for reliability-based design optimization: one deals with a truss structure subjected to random multiple point constraints, and the …

Reinforcing Digital Trust For Cloud Manufacturing Through Data Provenance Using Ethereum Smart Contracts, Trupti Narayan Rane

Engineering Management & Systems Engineering Theses & Dissertations

Cloud Manufacturing(CMfg) is an advanced manufacturing model that caters to fast-paced agile requirements (Putnik, 2012). For manufacturing complex products that require extensive resources, manufacturers explore advanced manufacturing techniques like CMfg as it becomes infeasible to achieve high standards through complete ownership of manufacturing artifacts (Kuan et al., 2011). CMfg, with other names such as Manufacturing as a Service (MaaS) and Cyber Manufacturing (NSF, 2020), addresses the shortcoming of traditional manufacturing by building a virtual cyber enterprise of geographically distributed entities that manufacture custom products through collaboration.

With manufacturing venturing into cyberspace, Digital Trust issues concerning product quality, data, and intellectual …

Study Of Microphonic Effects On The C100 Cryomodule For High Energy Electron Beam Accelerators, Caleb James Hull

Mechanical & Aerospace Engineering Theses & Dissertations

The Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Laboratory (JLab) is a particle accelerator which can accelerate an electron beam to relativistic speeds and apply the beam onto target samples. The C100 superconducting radio frequency (SRF) cavity is the primary accelerating structure of the C100 cryomodule, one of the many cryomodules which compose the CEBAF linear accelerator. SRF cavities are particularly sensitive to internal and external vibrations that can result in a phenomenon called microphonics which degrade the operational stability of a cryomodule.

The purpose of this thesis is to investigate the significance of mechanical disturbances on …

Evaluating Direct Filtration As An Alternative To Conventional Carbon-Based Advanced Treatment For Indirect Potable Reuse, Savannah M. Flemmer

Civil & Environmental Engineering Theses & Dissertations

Hampton Roads Sanitation District (HRSD) is recharging purified wastewater into the Potomac Aquifer via the Sustainable Water Initiative for Tomorrow (SWIFT) project. Conventional SWIFT treatment applies coagulation, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, and ultraviolet disinfection to secondary effluent to produce water that meets drinking water standards for managed aquifer recharge. HRSD is considering implementing direct filtration as an alternative to conventional treatment for two additional SWIFT facilities. Direct filtration presents an opportunity for significant cost savings by eliminating sedimentation, shortening flocculation detention time, and reducing coagulant usage. Without upstream removal of solids and organics, however, biofilters …

Data-Driven Predictive Modeling To Enhance Search Efficiency Of Glowworm-Inspired Robotic Swarms In Multiple Emission Source Localization Tasks, Payal Nandi

Mechanical & Aerospace Engineering Theses & Dissertations

In time-sensitive search and rescue applications, a team of multiple mobile robots broadens the scope of operational capabilities. Scaling multi-robot systems (< 10 agents) to larger robot teams (10 – 100 agents) using centralized coordination schemes becomes computationally intractable during runtime. One solution to this problem is inspired by swarm intelligence principles found in nature, offering the benefits of decentralized control, fault tolerance to individual failures, and self-organizing adaptability. Glowworm swarm optimization (GSO) is unique among swarm-based algorithms as it simultaneously focuses on searching for multiple targets. This thesis presents GPR-GSO—a modification to the GSO algorithm that incorporates Gaussian Process Regression (GPR) based data-driven predictive modeling—to improve the search efficiency of robotic swarms in multiple emission source localization tasks. The problem formulation and methods are presented, followed by numerical simulations to illustrate the working of the algorithm. Results from a comparative analysis show that the GPR-GSO algorithm exceeds the performance of the benchmark GSO algorithm on evaluation metrics of swarm size, search completion time, and travel distance.