Digital Commons Network^™

Utilization Of Finite Element Analysis Techniques For Adolescent Idiopathic Scoliosis Surgical Planning, Michael A. Polanco

Mechanical & Aerospace Engineering Theses & Dissertations

Adolescent Idiopathic Scoliosis, a three-dimensional deformity of the thoracolumbar spine, affects approximately 1-3% of patients ages 10-18. Surgical correction and treatment of the spinal column is a costly and high-risk task that is consistently complicated by factors such as patient-specific spinal deformities, curve flexibility, and surgeon experience. The following dissertation utilizes finite element analysis to develop a cost-effective, building-block approach by which surgical procedures and kinematic evaluations may be investigated. All studies conducted are based off a volumetric, thoracolumbar finite element (FE) model developed from computer-aided design (CAD) anatomy whose components are kinematically validated with in-vitro data. Spinal ligament stiffness …

Clostridioides Difficile Biofilm And Spore Production In Response To Antibiotics And Immune Stress, Adenrele M. Oludiran

Chemistry & Biochemistry Theses & Dissertations

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. C. difficile, an anaerobic spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections. C. difficile persists in the environment and spreads the infection to new hosts in the form of dormant spores and can persist within hosts as surface-attached biofilms. These studies investigate bacterial vegetative cell survival, biofilm formation, and sporulation in response to stress. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating …

Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore

Electrical & Computer Engineering Theses & Dissertations

Spin polarized photocathodes are necessary to examine parity violations and other fundamental phenomena in the field of high energy physics. To create these devices, expensive and complicated growth processes are necessary. While integral to accelerator physics, spin polarized electrons could have other exciting applications in materials science and other fields of physics. In order to explore these other applications feasibly, the relative supply of spin polarized photocathodes with a high rate of both polarization and photoemission needs to be increased. One such way to increase this supply is to develop the means to grow them faster and at a larger …

The Message Design Of Raiders Of The Lost Ark On The Atari 2600 & A Fan’S Map, Quick Start, And Strategy Guide, Miguel Ramlatchan, William I. Ramlatchan

Distance Learning Faculty & Staff Books

The message design and human performance technology in video games, especially early video games have always been fascinating to me. From an instructional design perspective, the capabilities of the technology of the classic game consoles required a careful balance of achievable objectives, cognitive task analysis, guided problem solving, and message design. Raiders on the Atari is an excellent example of this balance. It is an epic adventure game, spanning 13+ distinct areas, with an inventory of items, where those hard to find items had to be used by the player to solve problems during their quest (and who would have …

Challenging Predictions Of Inflationary Models With Cmb Data, Richik Bhattacharya, Atanu Debnath, Esha Sajjanhar, Shravani Sardeshpande, Pablo Tenorio Hernández, José Ricardo Torres Heredia

2022 REYES Proceedings

Cosmic inflation offers the best known explanations for many of the observed features of the Universe, such as its flatness. An imprint of the qualities of this mechanism is left in the cosmic microwave background (CMB), which can be instrumental to confirm inflation. Unfortunately, there is a plethora of inflationary models, which are a priori in the same footing. It is conceivable that contrasting the predictions of the various models with the measured values of the parameters of CMB data and other cosmological observables shall allow one to single out the successful theory of inflation. In this work we provide …

Statistical Genetic Discoveries Using Restricted Maximum Likelihood Method, Erika Wu

2022 REYES Proceedings

In statistical genetics, genetic association and genomic prediction become more successful with a highly heritable trait. Identifying highly heritable components of a complex disease can thus advance scientific understanding of the disease and potentially lead to effective prevention and treatments. Using Matlab and existing large-scale genome datasets, we evaluate a restricted maximum likelihood approach to identify highly heritable components of a complex disease as a function of multiple clinical variables.

Contrasting Sea-Ice Algae Blooms In A Changing Arctic Documented By Autonomous Drifting Buoys, Victoria Hill, Bonnie Light, Michael Steele, Andrew Lowy Sybrandy

OES Faculty Publications

Novel observations of the seasonal evolution of an ice algal bloom on the Chukchi shelf were collected by two autonomous buoys deployed 180 km apart in first-year drifting sea ice. High attenuation of blue light in the bottom of the ice indicated considerable accumulation of ice algae biomass with derived Chlorophyll-a concentrations (Chl a) up to 184 mg m⁻². Differences in the magnitude and persistence of ice algae biomass under each buoy appear to have been driven by differences in snow thickness, as ice thickness was similar between the sites. Minimal snow cover (0.02 m) around …

Design And Commissioning Of An E-Beam Irradiation Beamline At The Upgraded Injector Test Facility At Jefferson Lab, Xi Li, Helmut Baumgart, Charles Bott, Gianluigi Ciovati, Shaun Gregory, Fay Hannon, Mike Mccaughan, Robert Pearce, Matthew Poelker, Hannes Vennekate, Shaoheng Wang

Electrical & Computer Engineering Faculty Publications

The Upgraded Injector Test Facility (UITF) at Jefferson Lab is a continuous-wave superconducting linear accelerator capable of providing an electron beam with energy up to 10 MeV. A beamline for electron-beam irradiation has been designed, installed and successfully commissioned at this facility, aimed at the degradation study of 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS) in wastewater treatment. A solenoid with a peak axial magnetic field of up to 0.28 T and a set of raster coils were used to obtain a Gaussian beam profile with a transverse standard deviation of ∼15.0 mm at the target location. Monte-Carlo simulations using …

A Raft To Coastal Resilience: Odu Researchers Collaborate To Help Rural Communities Combat Flooding Impacts, News @ Odu

News Items

No abstract provided.

Career Literacy: Developing, Validating, And Establishing The Reliability Of The Career Literacy Continuum Scale, Kesha S. Valentine

STEMPS Theses & Dissertations

The purpose of this study was to develop a valid, reliable measure of career literacy skills called the Career Literacy Continuum Scale (CLCS). Career literacy is a person’s ability to read, understand, evaluate, and make decisions based on career-related information. The study participants were adolescents in grades 6 - 12 who attended public school in the southeastern United States. This study used an instrumentation research design and was conducted in two phases, item generation followed by test analysis and optimization.

Validity was established throughout the process by using content experts and establishing the item and scale validity indices. Item response …

Two-Current Transition Amplitudes With Two-Body Final States, Keegan H. Sherman, Feliipe G. Ortega-Gama, Raúl A. Briceño, Andrew W. Jackura

Physics Faculty Publications

We derive the on-shell form of amplitudes containing two external currents with a single hadron in the initial state and two hadrons in the final state, denoted as 1 + J → 2 + J . This class of amplitude is relevant in precision tests of the Standard Model as well as for exploring the structure of excited states in the QCD spectrum. We present a model-independent description of the amplitudes where we sum to all orders in the strong interaction. From this analytic form we are able to extract transition and elastic resonance form factors consistent with previous work …

Runtime Energy Savings Based On Machine Learning Models For Multicore Applications, Vaibhav Sundriyal, Masha Sosonkina

Electrical & Computer Engineering Faculty Publications

To improve the power consumption of parallel applications at the runtime, modern processors provide frequency scaling and power limiting capabilities. In this work, a runtime strategy is proposed to maximize energy savings under a given performance degradation. Machine learning techniques were utilized to develop performance models which would provide accurate performance prediction with change in operating core-uncore frequency. Experiments, performed on a node (28 cores) of a modern computing platform showed significant energy savings of as much as 26% with performance degradation of as low as 5% under the proposed strategy compared with the execution in the unlimited power case.

Developing Teacher Candidates’ Multicultural Lenses Through Disciplinary Writing Assignments, Kristie Gutierrez, Jori S. Beck, Kaavonia Hinton, Kelly Rippard, Yonghee Suh

Teaching & Learning Faculty Publications

The purpose of this study was to explore the effectiveness of providing scaffolded disciplinary writing assignments to develop teacher candidates’ multicultural lenses. This study was set in a secondary education program at one mid-Atlantic university. Faculty in this program focused on five dimensions of multicultural education (ME) to better serve teacher candidates within their program through the development of ME-focused disciplinary writing assignments. In required courses within the program, teacher candidates (TCs) completed assignments such as a student shadow experience, infographic, journal, community mapping activity, and practitioner journal article. Qualitative data were collected to explore TCs’ understanding of the ME …

Future Location For Odu's Institute For Coastal Adaptation And Resilience Will Foster Research And Experiential Learning, Jonah Grinkewitz

News Items

No abstract provided.

A Self-Regulating System For Assessing Scientific Predictive Power, Ted C. Rogers

Physics Faculty Publications

I propose a method for tracking and assessing scientific progress using a prediction consensus algorithm designed for the purpose. The protocol obviates the need for centralized referees to generate scientific questions, gather predictions, and assess the accuracy or success of those predictions. It relies instead on crowd wisdom and a system of checks and balances for all tasks. It is intended to take the form of a web-based, searchable database. I describe a prototype implementation that I call Ex Quaerum. The main purpose of the present document is to motivate the project, to explain it's underlying philosophy, to explain the …

Black Male Educators Matter: Modeling And Expectations In K-12 Settings, Denelle Wallace, Linda Bol, Kendra Hall, Erin Cousins

Educational Leadership & Workforce Development Faculty Publications

In light of the teacher shortage and increased emphasis on diversifying the educator workforce, the recruitment and retention of Black male educators is critical. The researchers focused on how these educators perceive their impact as role models and what others expect from them in K-12 contexts. The researchers administered questionnaires (N=38) and conducted interviews (N=11). Most educators considered themselves to be positive role models, especially for Black students. Expectations about their responsibilities as disciplinarians were positive unless imposed by race or at the expense of perceived academic skills. They needed to prove themselves with respect to academic qualifications. Interpersonal relationships …

Reflecting Back To Forge The Path Forward, Robert M. Capraro, Mary Margaret Capraro, Chance Lewis, Melva R. Grant, Marlon James, Eduardo Mosqueda, Jamaal Young, Jemimah Young, Ali Bicer, Tarcia Hubert, Alesia Mickle Moldavan, Susan Ophelia Cannon, Michael S. Rugh, Miriam Sanders, Jonas Chang

Teaching & Learning Faculty Publications

The JUME editorial team provides an update of the journal's health and progress during the 2021 calendar year and discusses coming changes and opportunities for growth.

Studies Of Bonus12 Radial Gem Detector And Tcs Beam Spin Asymmetry In Clas12, Jiwan Poudel

Physics Theses & Dissertations

The Barely Offshell Nucleon Structure (BONuS12) experiment adopted the concept of spectator tagging technique to study the nearly-free neutron structure function F2n in the CLAS12 of Jefferson Lab. A novel Radial Time Projection Chamber (RTPC) detector was built, tested and integrated into the CLAS12 system to detect a back-moving low momentum tagged proton in d(e, ep)X deep-inelastic scattering. It was a 40 cm long gaseous detector consisting of 3 layers of cylindrical GEM foils for the charge amplification, with the data readout directly from the surrounding padboard. The RTPC detected the recoiling spectator proton, in coincidence with …

Fragmentation In The Dual Enrollment Experience: The Importance Of Students’ Self-Perceptions In Dual Enrollment First-Year Composition Students, Sarah Crystal Johnson

English Theses & Dissertations

Dual enrollment has become an embedded aspect of our writing programs yet is still an under-researched area within rhetoric and composition. One reason for this research gap is that many DE students experience their FYC courses on secondary campuses, liminal spaces that are more difficult to access for research. DE students within these spaces experience daily tensions between the collegiate expectations of FYC curriculum and the secondary social contexts in which their DE FYC courses are taught. These unique contextual experiences impact their perceptions of themselves as writers. This research is an attempt to step into this DE research gap …

Investigating Psychological Capital As A Moderator In The Relationship Between Incivility And Stem Students' Major Embeddedness, Kristen Denae Eggler

Psychology Theses & Dissertations

Increasing the number of students who graduate from science, technology, engineering, and mathematics (STEM) majors is a national priority in the United States as there is a need for more STEM employees in the labor force. However, less than half of students who initially declare a major in STEM graduate college with a STEM degree, in part because of the unwelcoming climate in STEM. The aim of the current study was to understand how incivility may undermine a student’s embeddedness within their undergraduate major and whether the individual difference of Psychological Capital could assuage the undermining effects. The presence of …

Ion Production And Mitigation In Dc High-Voltage Photo-Guns, Joshua T. Yoskowitz

Physics Theses & Dissertations

One of the biggest obstacles to operating a GaAs polarized electron source with a long charge lifetime is the mitigation of ion back-bombardment. Several techniques exist to either clear ions from the accelerator or to mitigate ion damage of the photocathode. Predicting the effectiveness of these techniques requires sophisticated simulation models of electron impact ionization within the photo-gun. In this work, the effectiveness of applying a positive anode bias voltage to mitigate ion damage and increase the charge lifetime of the GaAs photocathode was studied over three run periods at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab …

Experimental Investigation Of All-Optical Production Of Metastable Krypton, Joshua Carl Frechem

Physics Theses & Dissertations

Metastable production of noble gases requires significant energy due to their filled valence shells. These transitions from the ground state are in the vacuum ultraviolet and extreme ultraviolet, which are relatively inaccessible to lasers. This necessitates the use of either electron/ion bombardment via inefficient glow discharges or the use of high-power lasers and nonlinear processes. The all-optical production efficiency using these high-power lasers promises to be orders of magnitude higher than glow discharges, but far more costly. This work looks to improve all-optical production of metastable krypton (Kr*) through the use of a commercially available vacuum ultraviolet lamp with a …

Frequency Agile Ofdm System For Radio Communication In High Frequency Bands, Erin E. Hill

Electrical & Computer Engineering Theses & Dissertations

High Frequency (HF) radio communication existed as the primary source of over-the-horizon communication for decades prior to the wide implementation of satellite and cellular networks. Even today, should satellite communication become unavailable, the robust backup of HF vitally supports long distance data transmission without the need of a cellular infrastructure. This capability is of particular importance to naval applications while at sea. Frequency choice, however, becomes critical in supporting reliable HF communication as too high of a frequency will not return to earth and too low of a frequency will result in high absorption rates within the atmosphere. A potential …

Entrepreneurship Education Relation To Mathematical Proficiency Amongst Secondary Youth, Mariam Abdelhamid

STEMPS Theses & Dissertations

Mathematical aptitude in the United States has been a concern over the past few decades, not only from an international perspective but from a student proficiency perspective. This phenomenon is also further negatively impacted due to COVID-19 associated learning loss. Correspondingly, there are calls for students to develop entrepreneurial skills to thrive in the 21st century economy. The purpose of this quasi-experimental study was to examine whether participation in an entrepreneurship class was related to mathematical proficiency (Algebra II) in high school. Data on students from two school districts were used, consisting of 2,741 and 1,172 Algebra II students in …

Electromagnetic Modeling Of A Wind Tunnel Magnetic Suspension And Balance System, Desiree Driver

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnels are used to study forces and moments acting on an aerodynamic body. While most results involve some interference from the mechanical supports used to hold the model, a Magnetic Suspension and Balance System (MSBS) is void of these interferences and presents an ideal test scenario. To further investigate the feasibility of dynamic stability testing at supersonic speeds using a MSBS, a preliminary design idea is currently being developed using an existing MSBS in a subsonic wind tunnel. This review focuses on the development of a mathematical model to more accurately portray the capabilities of the 6 inch Massachusetts …

Investigating Gluonic Operators In Coordinate Space, Wayne Henry Morris Iii

Physics Theses & Dissertations

In this dissertation, a method of extracting gluon momentum distributions inside hadrons, and particularly nucleons, is developed. In general, the utility and application of performing calculations in coordinate space at the operator level is discussed, and its application to the method of pseudodistributions in the lattice extraction of parton distributions. An introduction to the background field method and other techniques used in the calculation of corrections to gluon operators are provided. Then, an outline of the calculation of the uncontracted gluon bilocal operator at one-loop is given, and the result thereof. Using the result for the gluon bilocal operator restricted …

Deep Learning Object-Based Detection Of Manufacturing Defects In X-Ray Inspection Imaging, Juan C. Parducci

Mechanical & Aerospace Engineering Theses & Dissertations

Current analysis of manufacturing defects in the production of rims and tires via x-ray inspection at an industry partner’s manufacturing plant requires that a quality control specialist visually inspect radiographic images for defects of varying sizes. For each sample, twelve radiographs are taken within 35 seconds. Some defects are very small in size and difficult to see (e.g., pinholes) whereas others are large and easily identifiable. Implementing this quality control practice across all products in its human-effort driven state is not feasible given the time constraint present for analysis.

This study aims to identify and develop an object detector capable …

A Direct Method For Modeling And Simulations Of Elliptic And Parabolic Interface Problems, Kumudu Janani Gamage

Mathematics & Statistics Theses & Dissertations

Interface problems have many applications in physics. In this dissertation, we develop a direct method for solving three-dimensional elliptic interface problems and study their application in solving parabolic interface problems. As many of the physical applications of interface problems can be approximated with partial differential equations (PDE) with piecewise constant coefficients, our derivation of the model is focused on interface problems with piecewise constant coefficients but have a finite jump across the interface. The critical characteristic of the method is that our computational framework is based on a finite difference scheme on a uniform Cartesian grid system and does not …

Finding Core Members Of A Hedonic Game, Daniele M. Vernon-Bido

Computational Modeling & Simulation Engineering Theses & Dissertations

Agent-based modeling (ABM) is a frequently used paradigm for social simulation; however, there is little evidence of its use in strategic coalition formations. There are few models that explore coalition formation and even fewer that validate their results against an expected outcome. Cooperative game theory is often used to study strategic coalition formation but solving games involving a significant number of agents is computationally intractable. However, there is a natural linkage between ABM and the study of strategic coalition formation. A foundational feature of ABM is the interaction of agents and their environment. Coalition formation is primarily the result of …

Addressing Public Perceptions About Cell-Based Meat And Cellular Agriculture Through Metaphors, Yvette Emma Hubbard

English Theses & Dissertations

Today’s food movement places organic, holistic, and natural foods as priority. The idea aims for better human health, a farm-to-table community, and environmental sustainability. Soon a new meat alternative will become part of the ongoing food movement. What is it? Cell-based protein. It is a protein alternative to livestock protein. It is real protein from a real breathing animal. Cell-based beef for example is grown in a lab with cells from a living cow that does not have to die or be slaughtered. It is destined to become the new protein architecture on the horizon. Parts of this paper are …