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ASSESSMENT, MODELING, AND ADVANCED APPLICATIONS OF MARINE ENERGY SYSTEMS
Get PDFMarine Renewable Energy (MRE) technologies, particularly Ocean Current Turbines (OCTs) and Ocean Thermal Energy Conversion (OTEC), offer promising pathways for sustainable power generation in tropical and subtropical regions. This dissertation presents a comprehensive investigation into the resource potential, modeling, hardware-in-the-loop (HIL) testing, and application-driven evaluation of these systems for green hydrogen production and offshore aquaculture.
A novel HIL testbed was developed using a dynamometer and OPAL-RT real-time platform to emulate OCT dynamics under measured ocean current conditions. This setup enabled advanced testing of variable-speed and blade-pitch control strategies. Coupled with a PEM electrolyzer model, the system achieved instantaneous hydrogen production rates up to 0.64 g/s, with Gulf Stream-based extrapolations projecting up to 20 metric tons annually. Case studies further assessed electrolyzer performance under dynamic flow profiles and identified promising deployment sites through targeted resource mapping.
For OTEC, a high-resolution resource assessment using four years of HYCOM data in the Gulf of America and Caribbean revealed temperature differentials above 20 ◦C at depths as shallow as 500 m, favorable for nearshore and offshore deployment. A techno-economic analysis of hybrid OTEC–diesel–battery systems for coastal aquaculture showed that increasing OTEC capacity significantly reduces operational costs and energy losses while ensuring a stable power supply. Sensitivity analyses confirmed system viability under varying battery and diesel backup configurations, positioning OTEC as a critical enabler for resilient, sustainable fish farming operations within the emerging blue economy
EFFECTS OF CREVICE CORROSION ON METAL ADHESIVE PERFORMANCE AND SHEAR STRENGTH IN MARINE ENVIRONMENTS
Get PDFCorrosion is a leading challenge that engineers and researchers face when working in marine environments. Annually, corrosion costs an estimated $2.5 trillion globally and can lead to environmental damage and pose a threat to public safety. This thesis investigates the effects of crevice corrosion on the performance of different epoxy adhesives when mated with stainless steel to determine if using epoxy is a viable option for the development of systems operating in marine environments. To accomplish this, metal-to-metal lap shear samples were created using Araldite 2015-1, Plexus MA560-1, Plexus MA310, and Plexus MA8120 epoxies and different preparation methods. These samples were deployed in a natural marine environment for up to 6 months before bond strength and visible corrosion were assessed. While the samples with Araldite 2015-1 experienced the least amount of corrosion, with most bonds failing at 6 months, replication of the work done in this paper for real marine applications is discouraged
MAPLESS AUTONOMOUS NAVIGATION USING MONOCULAR VISION
Get PDFThis thesis investigates monocular vision-based navigation for autonomous ground robots in indoor environments. It explores the effectiveness of mapless navigation strategies using image inputs and evaluates both modular and end-to-end deep learning techniques. A comprehensive implementation pipeline was developed on a Clearpath Dingo robot, comparing the approaches: classical optical flow (Farneback), modular deep learning with motion planning, and an end-to-end model.
The modular methods involve predicting region-wise obstacle depths using a ResNet 18 based model trained on a custom indoor dataset, followed by a motion planner. The end-to-end approach leverages a ResNet-18 architecture to jointly predict steering angles and collision probabilities. All models were trained and evaluated using custom datasets collected in varied indoor trajectories, totaling over 100,000 images.
Experimental evaluation focused on both offline performance (e.g., RMSE, F1- score) and real-time deployment on the Dingo platform. Results indicate that while classical vision methods lack robustness, deep learning-based approaches demonstrate higher reliability and adaptability. Notably, modular models allow easier interpretability and integration with planning systems, while end-to-end models offer faster inference and smoother navigation.
This study validates the feasibility of deploying monocular vision-driven systems for indoor mapless navigation, highlighting trade-offs between interpretability, performance, and real-time constraints. The outcomes contribute to the broader field of robot autonomy using vision-only sensing, especially in low-cost, compute-constrained settings
DOES EXCLUSIVE BREASTFEEDING DURATION AND QUALITY AFFECT MATERNAL SENSITIVITY: FEAR VS. NORMATIVE SITUATIONS
Get PDFThe present study examined whether exclusive breastfeeding duration and perceived breastfeeding quality predict maternal sensitivity across emotionally challenging versus normative caregiving contexts in infancy. Twenty-four mother–infant dyads participated in three laboratory visits during which maternal sensitivity was assessed across interaction conditions. It was hypothesized that (1) longer breastfeeding duration would be associated with greater sensitivity during fear-inducing contexts, (2) breastfeeding duration and quality would interact to predict sensitivity, and (3) sensitivity would be higher during fear-inducing situations. Contrary to expectations, maternal sensitivity was highest in the normative/free-play condition and increased over time, peaking at 14 to 16 months. Exclusive breastfeeding duration was not significantly associated with maternal sensitivity. However, perceived breastfeeding quality emerged as a mediating variable influencing sensitivity across age and context. These findings suggest that positive breastfeeding experiences may promote parenting behaviors like emotional attunement and responsiveness, particularly in low-stress, free-play interactions
YOU ARE SAFE HERE: A PHENOMENOLOGICAL EXPLORATION OF PSYCHOLOGICAL SAFETY AND ORGANIZATIONAL OMBUDS IN HIGHER EDUCATION
No full textThis qualitative phenomenological study aimed to better understand the nature of ombuds’ psychological safety experiences in higher education by exploring how ombuds make meaning of their lived experiences with psychological safety and how it informs their roles with the constituencies they serve in higher education. Relying on data gathered related to the lived experiences of 12 organizational ombuds working at institutions of higher education, this study utilized one-on-one, open-ended, semi-structured interviews to collect data. The Four Stages of Psychological Safety was the conceptual framework used to study participants’ lived experiences. This study will contribute to the limited published empirical research related to organizational ombuds in higher education by providing recommendations for organizational ombuds practitioners to contribute to their effectiveness and to contribute to a body of knowledge that improves understanding of the role of organizational ombuds in higher education
INFLUENCES OF DYNAMIC AND STATIC RETRIEVAL CUES ON MEMORY ACCURACY AND REACTION TIMES
Get PDFPrior research on recognition memory has utilized static stimuli (e.g., words) to evaluate the time course of retrieval for different types of information —familiarity-based item memory and recollection-based associative memory. The present study investigated this time course in dynamic stimuli. Participants (N = 188) viewed videos at encoding, depicting 64 actors performing unique actions. At test, participants viewed either videos or images presented for short (733 ms) or long durations (1,466 ms). The test item types included old (same actor and action pairing), conjunction (novel pairing of familiar actor and action), new actor (unfamiliar actor, familiar action), and new action events (familiar actor, new action). False alarms to new action items increased when shown as images and to new actor items when shown as videos, suggesting that motion supported the retrieval of specific event components. Reaction times (RTs) were longer for images than videos, indicating that additional time was required to provide correct memory judgments to static stimuli. RTs were also longer for stimuli viewed for short durations compared to longer durations, suggesting additional time was necessary for accurate memory decisions under constrained temporal conditions. A hierarchical exponentially modified Gaussian model revealed distinct patterns in how stimulus type and duration impacted the RT distributions for the different test items. These findings offer insights into how stimulus modality and viewing duration at retrieval differentially impact memory performance and efficiency of retrieval
CULTIVATING MINDSETS OF PERSISTENCE: EXPERIENCES OF UNDERGRADUATE WOMEN STUDENTS IN STEM PROGRAMS AT A PUBLIC RESEARCH UNIVERSITY
Get PDFIn the fields of Science, Technology, Engineering, and Mathematics (STEM), women\u27s representation is disproportionately low across high school, higher education, and professional sectors. The purpose of this phenomenological study was to examine the factors influencing the persistence of undergraduate women STEM students at a public university by identifying available resources, uncovering obstacles and investigating their personal experiences. Data collection involved semi-structured interviews with a sample of 12 female participants enrolled as undergraduates in STEM majors at a public university. The research design chosen for the study was qualitative, focusing on stories from women’s experiences that provide an understanding of what influenced women’s decisions to stay in their STEM major at a public research university. Understanding how to enhance the overall experience of women in STEM programs is essential to ensure greater representation of women in these fields
COVID-19, BUSINESS RESILIENCE, AND GOVERNMENT CONTRACTING: DID THE PAYCHECK PROTECTION PROGRAM (PPP) IMPACT THE DISASTER RESILIENCE OF SMALL DISADVANTAGED BUSINESSES AFTER COVID-19? THE CASE OF GOVERNMENT CONTRACTING IN THE UNITED STATES.
Get PDFThis dissertation examines the disaster resilience of disadvantaged small businesses that have engaged in contracting activities with the U.S. federal government from 2018 to 2023. Federal government agencies procure goods and services from small businesses in the private sector through contracts that allow those businesses to be competitive in the market and overcome the impact of disasters on their activities. The notion of disaster resilience has traditionally focused on natural hazards like wildfires, earthquakes, tornadoes, or hurricanes; however, lately, it has been increasingly applied to diverse contexts. Business resilience to disasters refers to businesses\u27 ability to return to their pre-disaster activities and thrive following a calamity. Starting in early 2020, the COVID-19 virus caused millions of deaths worldwide and unprecedented business disruption for approximately two years. In March 2020, President Trump declared the pandemic resulting from the virus a national disaster. In response, the U.S. Congress enacted the CARES Act, which included the Paycheck Protection Program (PPP) to help American small businesses, primarily those owned by individuals from disadvantaged backgrounds, continue operating during and after this disaster. Millions of businesses, including recipients of federal government contracts, benefited from the program. With a focus on small businesses that were awarded federal government contracts each year from 2018 to 2023 and are owned by members of disadvantaged communities, such as minorities, women, and veterans, this dissertation explores the impact of the PPP loans on the disaster resilience of those businesses. Using publicly available government spending data from USASpending.gov and PPP loan information from the U.S. Small Business Administration (SBA), this dissertation analyzes the post-pandemic contracts awarded to those businesses by the federal government to determine the PPP’s impact on contracts awarded to those businesses post-pandemic. Following the data analysis, I found that, in general, PPP loans positively impacted the disaster resilience of small businesses engaged in federal government contracting. My findings revealed the effectiveness of the PPP as a federal disaster loan program. This dissertation applies the institutional theory on the impact of the PPP, as a policy, on business resilience, and addresses academic recommendations for additional studies on business resilience and federal disaster financial assistance for businesses engaged in public procurement
IMPROVING PATIENT OUTCOMES THROUGH IMPLEMENTATION OF THE KDOQI GUIDELINES FOR TUNNELED DIALYSIS CATHETER PLACEMENT
No full textThis quality improvement (QI) project aimed to enhance adherence to the Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines for placement of tunneled dialysis catheters (TDCs) in intensive care unit (ICU) patients. The project addressed inconsistent application of best practices related to TDC placement, improved documentation, improved communication using TigerConnect, a reduction in inappropriate catheter placements, and maintenance of a zero hospital-acquired tunneled dialysis catheter-related bloodstream infection (CRBSI) rate. Notably, some patients continued to be admitted with pre-existing community-acquired tunneled catheter-related infections, underscoring the effectiveness of the hospital’s internal infection prevention strategies while highlighting the need for enhanced collaboration with outpatient dialysis providers to reduce community-acquired infections. The intervention incorporated structured educational sessions and standardized assessment protocols. Participants included nephrologists, intensivists, interventional radiologists, advanced practice providers, and infectious disease doctors and infection prevention specialists. Data were collected through pre- and post-intervention surveys, chart audits, infection surveillance, and training completion rates. Descriptive statistics were used to evaluate adherence to the guidelines, safety outcomes, and the effectiveness of training. The findings demonstrated improved documentation, improved communication using TigerConnect, reduced inappropriate catheter placements, and continued hospital-acquired infection-free status since September 2024. The project highlighted the importance of interprofessional collaboration, vascular access planning, and system-level integration of best practices. Guided by Marilyn Ray’s Theory of Bureaucratic Caring, the initiative demonstrated how DNP-prepared nurses could lead organizational change by aligning policy-driven protocols with patient-centered care
GOTTA HAVE SOMEBODY: RENAL HEALTH AND CAREGIVING EXPERIENCES IN RURAL FLORIDA
No full textThis thesis examines the dynamics of care in the Everglades Agricultural Area (EAA) using the care circle model to highlight common experiences and themes during chronic kidney disease (CKD) management. Combining the theoretical frameworks of structural violence, social suffering, and care allowed the analysis of caregiving dynamics in the EAA, a community distressed by a history of structural violence that manifests today as poverty, environmental pollution, inadequate education, and poor health outcomes. Thematic analysis synthesizing the experiences of the care circles identified four themes: Geographical, logical, and economic constraints to healthcare; Cultural, linguistic, and educational barriers; Informal and formal support systems; Lived experiences of chronic kidney disease. These results encourage the incorporation of collective disease experiences into interventions aimed at increasing access to medical treatment