Digital Commons Network^™

Virginia Academy Of Science At 100: A Presentation Given To The Chemistry Section Of The Virginia Academy Of Science, Tom Devore

Virginia Journal of Science

While I have not been an active member of the Virginia Academy of Sciences (VAS) for all of its 100 years of existence, I have seen many changes in VAS during the more than 30 years that I have been an active member. This paper, delivered at the VAS Annual Meeting at the College of William and Mary on May 25, 2023, recalls some of the outstanding scientists in Virginia that I have had the privilege of knowing and who have led and lived out the goals of VAS. They inspired me to try to live up to the high …

How Changing Majors Impacts Academic Performance Among Undergraduate Students, Min Xu, Chandra R. De Silva

History Faculty Publications

This study investigates changing majors among undergraduate students. Through retrospectively tracking five graduating classes at a regional research university, the study provides empirical evidence as to when students declare their major, reach their final decisions about a major, and explores when it would be too late to change a major in order to graduate in a timely fashion. The study also examines the relationship between changing majors and academic performance. The results which suggest the need to provide students, especially freshmen with early proactive assistance in major selection might address concerns of parents and students about choosing a college major …

Some Notable Women Botanists In The Vas: Their Roles In Supporting The Development Of The Modern Flora Of Virginia, Marion B. Lobstein

Virginia Journal of Science

With the publishing of the 2012 Flora of Virginia by the Foundation of the Flora of Virginia Project, the dream of modern flora for Virginia was realized. This was a goal of the Virginia Flora Committee of the Virginia Academy of Science as well as other groups such as the Virginia Botanical Associates and the Virginia Native Plant Society. The Flora of Virginia and the 2017 Flora of Virginia App were realized with the work, support, and encouragement of many individuals and organizations. This paper focuses on the lives, contributions, and work of six women botanists in the Academy who …

Vas Annual Meeting Program Committee

Virginia Journal of Science

List of members of the VAS Annual Meeting Program Committee.

Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel

Chemistry & Biochemistry Theses & Dissertations

Cation exchange, a cornerstone of soil chemistry and nutrient cycling, is a fundamental chemical process that occurs in soils, sediments, membranes, and other solid materials. It involves the interchange of positively charged ions, or cations, between a solid matrix and a surrounding solution. This process is crucial in various natural and engineered systems, leading to a range of applications across different fields.

This dissertation presents an extensive investigation into the applications of cation exchange in the fields of biochar and bioenergetics, encompassing three distinct aims. The first aim concentrates on the surface oxygenation of biochar through ozonization, aiming to achieve …

Elasto-Plastic Behavior Of Single-Story Single-Bay Orthogonal Steel Space Frame Under Angular Earthquake, Mohammad Hamayoun Stanikzai

Civil & Environmental Engineering Theses & Dissertations

A study of the elasto-plastic behavior of single-story single-bay orthogonal steel space frame under an angular earthquake ground motion is investigated. The building frame is subjected to a horizontal earthquake ground motion not aligned with the building’s principal axes. Such a frame can develop biaxial bending and torsion in its members. The governing differential equations of equilibrium for the typical biaxially loaded sway beam-column are presented and iteratively solved using a finite-difference scheme. The effects of warping and residual stresses are accounted for in the analysis. The equations are used to predict the quasi-static elasto-plastic response of the frame when …

Performing Information Extraction For Mission Engineering Applications, Samuel R. Koski

Engineering Management & Systems Engineering Theses & Dissertations

The process of extracting structured data from unstructured and semi-structured text is manual, time consuming and error prone. Current natural language processing approaches for automating this process are difficult to verify for non-trivial and context-sensitive corpora. Large Language Models (LLMs) like ChatGPT have become a subject of considerable interest, opening a promising avenue of exploration. However, there is limited evidence on the performance of LLMs for information extraction.

In this dissertation, an approach is proposed to evaluate the accuracy of Stanford OpenIE and OpenAI's ChatGPT for this purpose. This includes comparing Resource Description Framework (RDF) triples extracted by each of …

Understanding The Impact Of Emergent Conflict On Communication And Team Cognition: A Multilevel Study In Engineering Teams, Francisco Cima

Engineering Management & Systems Engineering Theses & Dissertations

The development of team cognition is crucial for fostering high-performing teams. In cognitive-intensive fields like engineering, effective communication serves as a primary precursor to team knowledge development, enabling group members to effectively retrieve and utilize each other's expertise. Despite the critical role of communication, there is a lack of empirical research examining how conflict situations, which are critical emerging factors inherent to teamwork, interact with communication processes to constrain team knowledge development and utilization. This study, rooted in information processing theory, investigates how emerging conflict shapes multilevel team knowledge structures by interacting with communication processes in engineering project teams. Prior …

Effect Of Lunar Magnetic Field And Lunar Regolith Simulant On The Growth And Bioactive Compounds Production Of Chlorella Vulgaris Microalgae, Jeries Philip Butros Abedrabbo

Mechanical & Aerospace Engineering Theses & Dissertations

Since humans last went to the moon on the Apollo missions, there has been a fascination with inhabiting and colonizing other planetary objects, starting with the Earth’s Moon, Mars, and recently Jupiter’s moon, Europa. However, there is still lack of knowledge and science behind many of the extraterrestrial environmental effects on biological organisms living on Earth. Therefore, there is a need to study how such environments would affect these organisms. Moreover, how can we attain sustainable living in such environments as well through self-providing life support systems (LSS), without the need to provide for additional necessities back and forth from …

Combine Effects Of Heavy Storm, Sea Level Rise, And Wind-Induced Surge On Flooding In A Low-Gradient Coastal Watershed In Eastern Virginia, Rutvik Rajendrabhai Patel

Civil & Environmental Engineering Theses & Dissertations

This dissertation examines and presents mechanisms of flooding in a low-gradient coastal watershed, located in Virginia Beach, Virginia, USA. The watershed comprises the North Landing River watershed and the West Neck Creek watershed, both characterized by a low topographic gradient. The analysis relied on examining simulations generated using one-dimensional and two-dimensional HEC-RAS models. These models were developed using a 1-m digital elevation model (DEM) obtained from the U.S. Geological Survey (USGS). To calibrate and validate the models, unsteady flows resulting from historical hurricanes (e.g., Matthew, Sandy, and Isabel), southern winds, and/or rising sea levels were utilized. Some flows were caused …

Advancing Data-Driven Decision Making For Transportation Safety: Emerging Trends, Statistical Modeling, And Causal Inference, Guocong Zhai

Civil & Environmental Engineering Theses & Dissertations

Despite recent advances in data-driven decision-making for transportation safety, there remain potential biases in the decision-making for emerging trends (i.e., shared mobility, safe systems, vehicle electrification, and equity) in transportation. In that case, this dissertation aims to facilitate robust and equitable data-driven decision-making in transportation safety, addressing the potential biases: 1) spatial and inherent correlations across different types of crashes, 2) measurement error biases of exposures, 3) confounding biases, and 4) disparity biases in transportation safety.

To be more specific, four research objectives are demonstrated below. Chapter 3 assessed the safety performance of taxi and ride-hailing services by a multivariate …

A Study On The Use Of Reflective Writing Assessments To Indicate The Level Of Knowledge College Industrial Technology Students Possess Related To The Three Elements Of Technological And Engineering Literacy, William Domenick Euefueno

STEMPS Theses & Dissertations

The problem of the study was to determine if the use of a reflective writing assessment at the beginning, middle, and end of a college semester indicated an industrial technology student’s knowledge and skills related to technological and engineering literacy. Experiences gained during project-based learning activities were used as the basis for this study. This descriptive study examined the reflective writing abilities of junior and senior year college students enrolled in a university’s industrial technology program of study by administering a reflective writing assignment three times over a semester of science, technology, engineering, and math (STEM) course, STEM 320, Manufacturing …

Appalachia In The Anthropocene: An Approach To Understanding Neo Appalachian Narratives As An Affective Ecology, Rachel Michel Bates

English Theses & Dissertations

Appalachia is all too often a commodified and mythologized place in the American consciousness. Yet the lived experience of Appalachia is one complicated by widescale ecological devastation, high poverty rates, and most recently, a devastating opioid crisis. Though much of Appalachian literature continues to dwell in an old vision of Appalachia, an endeavor Zackary Vernon terms post-Appalachian, I argue that a subset of texts published around the turn of the millennium, a time when many of the labor-dependent, exploitative industries such as logging, hydro damming, and coal mining were no longer at work in the region, reveal a shift in …

Broadband Dielectric Spectroscopic Detection Of Volatile Organic Compounds With Zinc Oxide And Metal-Organic Frameworks As Solid-State Sensor Materials, Papa Kojo Amoah

Electrical & Computer Engineering Theses & Dissertations

The industrial revolution drove technological progress but also increased the release of harmful pollutants, posing significant risks to human health and the environment. Volatile organic compounds (VOCs), which have various anthropogenic and natural sources, are particularly concerning due to their impact on public health, especially in urban areas. Addressing these adverse effects requires comprehensive strategies for mitigation as traditional gas sensing techniques have limitations and there is a need for innovative approaches to VOC detection.

VOCs encompass a diverse group of chemicals with high volatility, emitted from various human activities and natural sources. These compounds play a crucial role in …

A Variable Shape Metastructure Based On Controlled Bistable Structural Elements, Mehmet R. Simsek

Mechanical & Aerospace Engineering Theses & Dissertations

The so-called hybrid position feedback controller is an unstable-then-stable position feedback controller, which is a second-order single-degree-of-freedom system in nature. This hybrid controller takes advantage of the resonant mode of a bistable system about one equilibrium position, destabilizes the system, and dynamically induces snap-through between the two equilibria. In this dissertation, a new multi degree of freedom metastructure concept that utilizes the hybrid position feedback controller is introduced. An arbitrary number of bistable “segments” or “structural elements” are attached to each other in a serial (or parallel) manner to generate a “distributed” bistable structure – also referred to as a …

Study Of Deep Learning Models To Classify Nasa’S Kepler Light Curves, Heena Minnich

Computer Science Theses & Dissertations

The search for exoplanets has been an ongoing effort since the first discoveries of planets beyond our solar system in the 1990s. Finding a potentially habitable planet outside our solar system could provide key insights on life elsewhere in the universe. NASA Missions such as the Kepler, launched in 2009 and completed in 2018, have provided a massive amount of data in this goal by using the transit method to discover repetitive and periodic dips in visible light around a star. The transit method has been used to measure flux, the brightness of a star over time. These flux time …

Examining The Role Of Access To Capital, Social Capital Networks, And Education In Supporting Black Founders And Investors In Technology-Based Entrepreneurship, Akosua Acheamponmaa

Engineering Management & Systems Engineering Theses & Dissertations

In recent years, a report from the Kauffman Index of Startup Activity shows that 540,000 Americans launch businesses each month (Fairlie et al., 2017). However, the number of women-owned and minority-owned businesses in the United States (U.S.) is disproportionately less than the proportion of women and minorities in the U.S. Although women slightly outnumber men in the U.S. (U.S. Census Bureau, 2019), new women-owned businesses represent only 39.4% of all U.S. businesses, while new male-owned businesses represent 60.51% (Fairlie et al., 2017). While Blacks or African Americans comprise approximately 13.4% of the U.S. population (U.S. Census Bureau, 2019), only 9.24% …

A Trustworthy Self-Sovereign Data And Identity Management Framework, Efat Fathalla

Electrical & Computer Engineering Theses & Dissertations

Data is a fundamental building block in the digital world, providing a basis for decision making and growth across numerous applications. In our modern world, we have become accustomed to collecting data on everything, including devices, machines, and people. The increased value of such data has led to aggressive harvesting mechanisms that prioritize data collection, storage, and pervasiveness while often disregarding security, privacy concerns, and compliance with regulations and standards. Such a pervasive attitude towards data has resulted in a loss of control, prompting concerns among individuals and mobilizing the scientific community towards advocating for data self-sovereignty.

Self-Sovereign Identity (SSI) …

Law’S Impact On Collaboration: A Three-Case Study Of Federal Advisory Committees Managed By The U. S. Coast Guard, Brian K. Mcnamara

School of Public Service Theses & Dissertations

Much remains to be learned about law’s impact on collaboration. Although law is one of the foundational disciplines of public administration, scholars assert that the field focuses on management principles to the detriment of law. Whether this assertion is correct as a general matter for the field, collaboration scholarship lacks empirical examination of the law’s role in collaboration processes.

This three-case study of federal advisory committees managed by the U.S. Coast Guard examines law’s impact on collaboration through the lens of Thomson and Perry’s (2006) Process Model. A qualitative method is used to capture participants’ perceptions of law and their …

The Impact Of Guided Notes Intervention On Learning Achievement, Quality Of Notes, And Perception, Bryan Richard Biggers

STEMPS Theses & Dissertations

Guided notes in the form of teacher-prepared materials that guide students through the lesson with cues and space have been recommended as a possible aid to support student learning. The present study investigated the results of guided notes on the students’ learning achievement, the quality of the students’ notes, and the students’ perceptions of note-taking. Sixty students were enrolled in an eight-week, asynchronous, online, general education course and were divided into nonintervention and intervention groups where the nonintervention groups took notes without support while the students in the intervention group took notes with guided notes during weeks two through seven. …

Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi

Civil & Environmental Engineering Theses & Dissertations

Presented herein is an experimental and theoretical study of biaxially loaded hollow rectangular section steel beam-columns with applied torsion at elevated temperatures. The theoretical analysis is based on a system of simultaneous materially nonlinear differential equations of equilibrium for which an iterative semi-analytic solution approach is formulated. Although the primary goal of this research is to study the influence of elevated temperatures on the steel member with the complex loading, rigorous analysis is also conducted of the member at ambient temperature for comparison. The experimental part of the study involves conducting tests on the members at both ambient and high …

Biochar For Heavy Metal Removal In Water: Opportunities, Challenges, And Sustainable Solutions, Pushpita Kumkum

Civil & Environmental Engineering Theses & Dissertations

The presence of heavy metals in drinking water is a significant concern due to the harmful impacts it can have on human health. Biochar has emerged as a low-cost alternative to activated carbon for lead (Pb) adsorption due to its porous structure and high surface-to-volume ratio. The last 10 years of studies have been reviewed to investigate the biochar production, activation methods, kinetic, adsorption isotherms, mechanism, regeneration, and adsorption capacities to guide future researchers and practitioners in using biochar to remove Pb from water. However, several challenges hinder the actual application of biochar as an adsorbent. These challenges include variability …

Maneuverability Of Cuttlefish And Squid: An Integrated Kinematic And Hydrodynamic Analysis, Alissa Marie Ganley

Biological Sciences Theses & Dissertations

Turning is important for life underwater, playing roles in predator avoidance, prey capture, locomotion, and communication. While turning abilities have been explored in many taxa, little is known about maneuverability of cephalopods, such as cuttlefishes and squids. The objectives of this dissertation include: (1) quantifying the turning abilities of cuttlefish hatchlings and determining whether there are species-specific differences; (2) examining the turning capabilities of adult cuttlefishes, with the goal of comparing adult performance with that of conspecific hatchlings; and (3) quantifying how adult neritic squids perform turns to provide a broader context of maneuvering strategies in cephalopods. To investigate turning, …

Compassionate Communication, Social Support, And Safety: Needs Of People Experiencing Homelessness, Emma Lynn Jackson

Communication & Theatre Arts Theses

On any given night in 2023, approximately 650,000 people were experiencing homelessness (HUD, 2023). With the highest rate of homelessness since national reporting began in 2007 and double the rate of chronic homelessness since 2016, it could be inferred that the resources are not effectively mitigating the problem (HUD, 2023). To attempt to understand this complex issue, this thesis initially reviewed theories on societal structures, personal connections, social support, and gaps in support. In person interviews of 14 people living with homelessness explored perceptions of support, social challenges, involvement in the community and lack of support. Following each interview, a …

Modeling The Impact Of Connected And Automated Vehicles On Driving Behaviors And Safety: A Driving Simulator Study, Abdalziz Alruwaili

Civil & Environmental Engineering Theses & Dissertations

Connected vehicles (CVs), equipped with advanced sensors, can communicate safety messages to drivers. Automated vehicles (AVs), designed with the ability to automate safety critical control functions, will redefine the traditional role of drivers. This dissertation aims to investigate the impact of connected and automated vehicles (CAVs) on driving behaviors and safety outcomes using data from driving simulator experiments. More specifically, the research objectives include:

1. Modeling the impacts of CVs on driving aggressiveness and situational awareness in highway crash scenarios.

2. Modeling the impacts of CV technologies on driving behaviors and safety outcomes in highway crash scenarios under diverse weather …

Impact Of Climate Change On Carbon And Nitrogen Balance In Zostera Marina L. (Eelgrass), Malee Jinuntuya

OES Theses and Dissertations

Seagrasses face vulnerability to both global stressors like Ocean Acidification (OA) and climate warming compounded by local stressors such as eutrophication that reduces light availability, leading to a complex dynamic of positive and negative effect on their growth and survival. Increased dissolved aqueous CO₂ (CO_2(aq)) benefits seagrasses by enhancing photosynthetic and growth rates, but it may increase nutrient demand, potentially depleting nutrient supply, especially in oligotrophic environments.

In this study, the long-term impact of CO₂ on Zostera marina L. (eelgrass) were investigated across a gradient of CO_2(aq) concentrations (55 – 2200 µM CO_{2(aq)) …}

Scaled And Graduated Learning In Deep Relu Networks And Reconstructing Depp Inelastic Scattering Kinematics, Abdullah Ayar Farhat

Mathematics & Statistics Theses & Dissertations

To address computational challenges in learning deep neural networks, properties of deep RELU networks were studied to develop a multi-scale learning model. The multi-scale model was compared to the multi-grade learning models. Unlike the deep neural network learned from the standard single-scale, single-grade model, the multi-scale neural networks use low scale information from all hidden layers, and thusly provide a robust approximation method that requires fewer parameters, lower computational time, and is resistant to noise. It is shown that the multiscale method is not subject to issues arising from the vanishing gradient problem. This allows very deep multi-scale networks to …

Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a study of the dynamic soil-structure interaction response of tapered wood utility poles embedded in various foundation soils subject to quasi-static and dynamic wind loads. The study includes the effects of nonlinear soil behavior with varying quantities of moisture and nonlinear cable tension loads on a class H1 wood pole. The natural frequency response of the pole is determined using a finite element formulation. The dynamic response in the presence of wind-induced forcing function is studied using a SAP2000 finite element scheme with wind speeds up to 220 mph. The natural frequency of the …

Online Learning As A Tool For Accessibility For Autistic Higher Education Students, Keirnan E. Brown

STEMPS Theses & Dissertations

Online learning is becoming more prevalent (Aylmer, 2020) and institutions are seeing an increase in disabled students (HEFCE, 2017; Italian National Agency for the Evaluation of the University System and Research [ANVUR], & National Conference of University Delegates for Disability [CNUDD], 2021; Rao, Edelen-Smith, & Wailehua, 2015). Meanwhile, this group experiences an achievement gap concerning learning and outcomes (ECU, 2017; Eurostat, 2014; Eurostat, 2019; Pearson et al., 2019). Therefore, exploring potential uses of online learning may be beneficial. One related use for online learning is its potential as a tool for accessibility for autistic students. Moreover, a literature gap exists …

Quasi-Static And Impact Load Response Of Bfrp-Reinforced Concrete Beams And Post-Terrorist-Attack Sub-Assemblages, José Luis Carrasquillo

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a theoretical and experimental study of Basalt Fiber Reinforced Polymer (BFRP) reinforced concrete beams and post-terrorist-attack subassemblages subjected to either quasi-static or impact load. Both BFRP reinforcement as well as BFRP fabric are used in this investigation. The sub-assemblage consists of an otherwise two-span beam converted to a fixed-end single-span one owing to the loss of a middle column blasted off during the terrorist attack. The simply supported beams are subjected to a midspan quasistatic or an impact load. However, each sub-assemblage is subjected to a quasi-static load up to collapse to simulate the …