Engineering Commons^™

Leveraging Systems Thinking For Global Environmental Health, Martha M. Mcalister

USF Tampa Graduate Theses and Dissertations

Environmental health inequities such as household air pollution, inadequate water, sanitation, and hygiene, and chemical pollution persist globally and have myriad consequences on individual and societal well-being. Unfortunately, while billions of dollars and countless hours of research have been applied towards addressing these issues in development, humanitarian, and environmental justice contexts, attempts to reduce the environmental burden of disease can seem successful at first, but then backslide to pre-intervention conditions (or worse). This is indicative of policy resistance, a tendency of complex systems that makes it very difficult to enact change if the “rules” of the system are misunderstood. There …

An Analysis Of Driven Pile Relaxation In Florida Soils, Dalton E. Knowles

USF Tampa Graduate Theses and Dissertations

Prestressed concrete piles (PCP) are a common geotechnical foundational element employed in marine and land bridges. PCP are commonly driven by an impact diesel hammer until the desired nominal bearing resistance is reached at the end of the initial drive (EOID). At a later time, the pile resistance may be verified, but not always, via a restrike, usually with the same impact hammer. At the beginning of a restrike, the resistance of the pile is rarely equal to the resistance at the EOID either increasing, known as set-up, or decreasing, known as relaxation. Set-up is clearly beneficial, however, this thesis …

Dissolved Nitrogen Removal In Biochar Amended, High Permeability Media For Urban Stormwater Treatment, Mark Vicciardo

USF Tampa Graduate Theses and Dissertations

Nutrient pollution in stormwater drives the eutrophication of inland and costal waterbodies which leads to sea grass retreat and the proliferation of harmful algal blooms (HAB). These anthropogenic effects destabilize ecosystems, and some HABs can pose direct human health risk. Bioretention, or the storage and controlled discharge of stormwater run-off in an ecologically engineered setting, is a potential solution to this problem. However, it relies heavily on the settling of particles as a nutrient removal mechanism, and thus struggles with pollutants, such as dissolved nitrogen, which is a particular problem in Florida where the geological prominence of phosphorus leaves nitrogen …

Programmable And Scalable Bit-Sliced Vlsi Architecture For Decision Tree Based Machine Learning Edge Inference, Raaga Sai Somesula

USF Tampa Graduate Theses and Dissertations

As the volume and diversity of Internet-of-Things (IoT) data continues to grow, traditional cloud-based processing methods face significant challenges, including latency, bandwidth constraints, and privacy concerns. Our research focuses on employing decision trees (DTs) as an intelligent filtering mechanism on the edge. Preliminary comparisons across four datasets revealed DTs are significantly more efficient than multilayer perceptrons (MLP), saving 97-98\% in area and power, leading to the selection of DT for our proposed architecture for lightweight IoT devices. We propose a novel programmable and scalable custom application specific integrated circuit (ASIC) architecture designed for Decision Tree based ML inference. Each bit-slice …

Effects Of Unobservable Bus States On Detection And Localization Of False Data Injection Attacks In Smart Grids, Moheb Abdelmalak

USF Tampa Graduate Theses and Dissertations

In an era increasingly marked by sophisticated cyber-attacks, this thesis investigates the critical issue of bus unobservability in smart grids and its impact on the effectiveness of cyber-attack detection and localization models. Given that unobservability is a prevalent challenge in smart grids due to various factors, researchers have developed numerous algorithms for optimal Phasor Measurement Unit (PMU) placement under scenarios of limited observability. However, these models primarily focus on enhancing network observability, often without considering whether this placement optimally facilitates attack detection. This research is driven by the hypothesis that a deeper understanding of the effects of unobservable buses can …

Under Pressure: The Soft Robotic Clap-And-Fling Of Cuvierina Atlantica, Daniel Mead

USF Tampa Graduate Theses and Dissertations

Evolution over billions of years has led to unique animals of all types. The tiny sea butterfly is one that remains mostly anonymous because of its size and low place on the food chain, but it is a swimming creature that when examined closely reveals a surprise. Shockingly, it has a swimming motion nearly identical to small insects flying at intermediate Reynolds numbers, referred to as the clap-and-fling. The centimeter long pteropod flapping briskly at 5Hz escapes attention with its size and speed. Modeling the clap-and-fling motion of the sea butterfly at a larger scale allows the benefits and uniqueness …

Nutrient Removal Of Biochar Amended Modified Bioretention Systems Treating Nursery Runoff, Nicholas Richardson

USF Tampa Graduate Theses and Dissertations

Excess inputs of nutrients, such as nitrogen and phosphorus, to surface water bodies can lead to the presence of harmful algal blooms (HABs). HABs can damage their surrounding environments and the economies dependent on them. Nutrient pollution can be properly controlled and monitored at point-sources, such as wastewater treatment plants, but is more difficult to control for non-point sources, such as fertilizer runoff. One form of fertilizer runoff that remains overlooked is runoff from plant nurseries. Controlled release fertilizers (CRFs) embedded in plant containers at nurseries can leach excess nutrients into the runoff. For nurseries in Florida, best management practices …

Single And Dual Cell Encapsulation Via Liquid Core Hydrogels Using Pico Injection, Jade Houston

USF Tampa Graduate Theses and Dissertations

In this project, a comprehensive microfluidic device, along with several interdependent subsystems, was designed and developed in SolidWorks, leveraging a combination of 3D resin printing with biocompatible resin and micromachining with polymethylmethacrylate (PMMA). The microfluidics chip integrated both passive and active components to facilitate its primary function: dual cell encapsulation via liquid core sodium alginate hydrogel droplets.

Integral to the microfluidics chip design were key features including a 5-convolution Archimedes spiral for particle sorting, a flow focusing junction for droplet generation, and a pico injector for injecting additional cells into passing droplets via the manipulation of an electric field.

An …

Development Of A Plant Growth And Health Monitoring System Using Imaging And Sensor Array Information For Cubesat Applications, Kat-Kim Phan

USF Tampa Graduate Theses and Dissertations

Space exploration has been a topic of interest in the scientific community, such as the planned missions to Mars. To accomplish this would require being able to provide astronauts with a steady supply of food beyond freeze-dried foods leading to the need to grow food in space. Although this is a topic still being investigated, the CubeSat platform opens the possibility of carrying out studies on plant growth under more strenuous space conditions unlike that in the International Space Station (ISS). Developing a plant-focused mission for a CubeSat, though, entails being able to develop a system to sustain plant life …

Temporospatial Deep Learning Strategies For Prediction Of Disease Progression In Radiology, John D. Mayfield

USF Tampa Graduate Theses and Dissertations

While the fields of machine learning and medicine are deeply rooted in axiomatic scientific principles, there is an element of art that makes the practice imperfect, yet innately human. As the two fields have seen the greatest overlap in their collective history, there remains a chasm between them in terms of practical translation for the patients who desire and deserve personalized medicine. As presented in this dissertation, I and my collaborators have contributed to the groundwork for future exploration of predicting disease progression by identifying signals within sequential medical imaging to provide a temporospatial relationship upon which we can make …

Surface Modification Of Poly(4,4'-Oxydiphenilene Pyromellitimide) With Low-Pressure Plasma Treatment, Cihan Aktas

USF Tampa Graduate Theses and Dissertations

This study explores the change of the wetting characteristics of commercially availablepolyimide (PI), Kapton® HN, films a type of poly(4,4′-oxydiphenylene-pyromellitimide), following treatment with low-pressure plasmas of carbon tetrafluoride (CF4), air, hydrogen (H2), carbon-dioxide (CO2) and oxygen (O2) gases as well as the surface texturing via laser-exposure procedure. The water contact angle (CA) and surface free energy (SFE) of untreated PI films were determined as 82.4°±0.8 and 45.0±0.3 mN/m, respectively. After CF4 plasma gas treatment, the CA value of PI films increased to 110.2°±1.0, while it decreased to 9.3°±2.3 after O2 plasma gas treatment. The surface free energy (SFE) of PI …

Development Of A Suspended Aerobic Membrane Bioreactor (Sambr) For Sustainable Wastewater Treatment On Early Planetary Bases, Talon James Bullard

USF Tampa Graduate Theses and Dissertations

Environmental Control and Life Support Systems (ECLSS) ideally should treat all “waste” streams for recovery in a sustainable and near closed-loop manner. This will be critical for Partial Gravity Habitats (PGH) and Early Planetary Bases (EPB) that will be established on the Moon and Mars due to the lack of readily available resources. Currently, the Water Recovery System (WRS), onboard the International Space Station (ISS), recovers and purifies water from urine and graywater. While efficient, this system is not optimized for future missions and utilizes physical-chemical technologies that operate with single-use and hazardous consumables. In response to the lack of …

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

Multi-Model Digital Twins With Ai Forecasting For Seed To Stand Supply Chain, Rania Sherif Elashmawy

USF Tampa Graduate Theses and Dissertations

The present dissertation embodies a multi-faceted investigation aimed at enhancing strawberry production pre-harvest and post-harvest quality through data-driven approaches. It unfolds multi-stages framework.

The first stage presents a complete data collection and its preliminary statistical analysis obtained from the first phase of a large-scale soil study on how to improve strawberry production and achieve sustainable and high-quality harvests through sensor-assisted real-time field monitoring. Six real-time loggers were placed in an operational commercial strawberry farm in Central Florida for the entirety of a harvest season from soil preparation to planting to harvesting. Along with high-resolution soil sensory measurements including water content, …

Swelling Induced Buckling Of Photopatterned Hydrogel Beams, Chinar Yogesh Kokaje

USF Tampa Graduate Theses and Dissertations

The main goal of this study was to learn more about swelling induced buckling of surface-attached gel lines photo-patterned from thermally responsive polymers. A library of 10 different polymer compositions was synthesized using methacryloyloxybenzophenone (MABP) as the photo-cross-linking monomer. For each of the polymers, a series of beam-like patterns were prepared on polystyrene tissue culture dishes by first depositing a known amount of polymer into the tissue culture dish followed by pattern generation using a photo-lithography mask with line widths of 10, 20, 30, 50, and 80 μm. The target height of each polymer line was 100 μm. After development …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Machine Learning For Electronic Design Automation: Specification Mining And High-Level Synthesis, Md Rubel Ahmed

USF Tampa Graduate Theses and Dissertations

The rapid growth of complex system-on-chip (SoC) designs has presented unprecedented opportunities and challenges in electronic design automation (EDA). This dissertation explores two facets of electronic design automation: message flow specification mining using data mining and natural language processing (NLP) and high-level synthesis (HLS) acceleration using different machine learning (ML) methods. It also discusses an ML model co-optimization method for energy-efficient hardware implementation.

Effective SoC design validation relies heavily on message flow specifications. This dissertation presents an efficient technique for synthesizing finite state automaton (FSA) models from SoC execution traces. The synthesized models can provide valuable insights into the on-chip …

Durability Of Cfrp/Steel Bond In Natural Weather, Mastour Alsulami

USF Tampa Graduate Theses and Dissertations

Fiber reinforced polymers (FRP) are increasingly being used for infrastructurestrengthening and repair of steel structures. Though there have been several durability studies, exposures used are not representative of outdoor service conditions. Fewer studies have explored the effect of changing outdoor conditions typical in infrastructure use. The goal of the research is addressing this gap by evaluating the performance of commercially available CFRP systems under natural weather characteristic of hot, humid tropical conditions mainly and cold weather secondary in three different locations.

Thirty CFRP/steel joint specimens were prepared in laboratory conditions and exposed to ambient temperature on the Engineering building roofs …

Reynolds-Averaged Navier-Stokes Simulations Of Nearshore Langmuir Circulation And The Formation Of Oil-Particle Aggregates, Juan J. Penaloza Gutierrez

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the inner shelf coastal ocean is characterized by Langmuir circulation (LC) or cells that can span the full depth of unstratified water columns. A Reynolds-averaged Navier-Stokes (RANS) simulation strategy resolving full-depth LC coupled with an oil-particle aggregate (OPA) formation model is introduced. The RANS methodology is employed in two different cases. The first case corresponds to a shallow shelf zone of uniform depth, focusing on vertical mixing and transport of OPAs. The second case pertains to a surf-shelf transition zone with variable depth, comprising vertical and horizontal mixing of OPAs. In the latter case, a wave model …

Mechanisms Contributing To Hydrogen-Influenced Early Failure Of Bridge Tendons, David Dukeman

USF Tampa Graduate Theses and Dissertations

Failures in post-tensioned tendons have occurred without warning due to fractures in the high-strength steel strands. These strands are cold-drawn to increase their strength while still retaining the preferential ductile mode of fracture. Recently, a tendon failure that occurred in an upper deviation block of the I-526 James B. Edwards bridge crossing the Wando river showed signs of corrosion and potentially another method of failure, hydrogen embrittlement. One proposed source of hydrogen is through galvanic coupling that may exist between the galvanized steel duct and the steel strands. This coupling, if substantial, can promote hydrogen evolution at the steel strand's …

Optimizing The Dynamic Replacement Of Soft Soils With Sand Using A Fem Tools, Walid Salem A Elsiwi

USF Tampa Graduate Theses and Dissertations

First a dynamic finite element methodology (FEM) was developed to simulate an entire dynamic replacement (DR) program of clay with sand involving multiple poundings. The main objective of this research was to employ FEM and geotechnical test data such as cone penetration test (CPT) data at the site to predict the maximum achievable sand column (SC) depth and the corresponding optimum levels of attributing parameters such as number and height of pounder drops. Another goal was to predict the pore pressure generated in clay due to pounding. A full-scale ground improvement project was used to guide the analytical process. Comparison …

Interdependency Between Water And Road Infrastructures: Cases And Impacts, Shihab Uddin

USF Tampa Graduate Theses and Dissertations

This dissertation studies the interdependency between road and water infrastructures and associated interdependency impact on these two critical infrastructure systems. Critical infrastructures and the interdependency among these infrastructures have gained much attention recently because of its growing complexity, importance, and vulnerability to natural and man-made threats. In response, researchers have spent significant effort to study these infrastructures individually as well as when they are interdependent to understand complex interdependency relationship and to figure out ways to make these infrastructures more reliable, robust, and resilient. However, water and road infrastructure systems have not been studied as vastly as other critical infrastructures …

Advanced Multiscale Molecular Dynamics Simulations Of Amorphous Polymers, Sahar Zenoozi

USF Tampa Graduate Theses and Dissertations

Polymers are in a wide range of material forms with various resources, including natural to synthetic processes. Polymers consist of covalently bonded monomers to each other. The chain length of polymers varies from a few monomers to thousands of monomers. This wide range of chain length enables polymers with attractive capabilities of chemical and physical properties. Thus, polymers are highly attractive in different scientific and industrial applications such as drug delivery, optical coatings, catalysts, semiconductors and organic photovoltaics. This work has combined updated accurate methods for accurate initial conformations, and modified force field parameters to produce a generalized method for …

Novel Systems Engineering Framework Analysis Of Photovoltaic Models And Equations, Peter R. Michael

USF Tampa Graduate Theses and Dissertations

This dissertation analyzes Photovoltaic PV equations and models for silicon based systems from a Systems Engineering framework. Background information includes an introduction, a summary of the state of PV use, a brief history of photovoltaics, and the detailed derivation of equations that enable the finding of the PV parameters contained in the PV models.The novel inquiry, leveraging systems engineering frameworks, includes three areas useful in analyzing PV equations and models. The first is a statistical verification of common simplifications of PV equations at the primary conditions of short circuit, open circuit, and maximum power. Additional analysis shows other simplifications that …

Integrated Periphyton Biofilters In Marine Recirculating Aquaculture Systems, Adam N. Bell

USF Tampa Graduate Theses and Dissertations

Marine aquaculture is a growing industry that has the potential to reduce eutrophication, overfishing, and loss of biodiversity. Recirculating aquaculture systems (RAS) are a type of aquaculture system that decreases discharge, raises biological control, and conserves water; however, RAS are challenged due to high energy cost, low biodiversity, water quality control, and waste nutrients. Periphyton biofilters are a new technology that allows for feed production, water quality control, microbial diversity, and resource recovery in marine aquaculture systems. The overarching question that this dissertation investigates is, how can periphyton biofilters be integrated into RAS to address the challenges of modern sustainable …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Top-Down Nanomanufacturing Of Anisotropic Two-Dimensional Metals, Md Rubayat-E Tanjil

USF Tampa Graduate Theses and Dissertations

Two-dimensional (2D) materials have introduced a transformative era in materials science with extensive research being performed to gain a fundamental understanding of their diverse properties and applications. Amongst the broader 2D material family, 2D metals or 2D metallic nanosheets (2DMNSs) typically denotes the nanometer-scale thin elemental metals, compound, or alloys, which shows superlative chemical and physical properties compared to bulk counterparts due to the reduced dimensionality. 2D materials’ widespread direct physical or chemical isolation techniques have been facilitated due to their intrinsic van der Waals layered morphology, whereas 3D close-packed bulk metals with isotropic bonding hinder their facile isolation in …

Iot Architecture For Enhancing Wayfinding And Accessibility In Smart Cities, Myles Keller

USF Tampa Graduate Theses and Dissertations

This research explores the potential of the Internet of Things (IoT) in enhancing urban wayfinding, particularly for the blind and visually impaired (BVI). Utilizing IoT's multi-layered architecture, smart cities deploy integrated sensors and devices to address urban challenges, with wayfinding as a key focus. While various accessible wayfinding methods have been explored, there exists a gap for more efficient solutions. Within this context, a collision warning system was developed for the BVI, integrated within a broader body sensor network (BSN) framework. Building on this, the study presents AWayNet, an RFID-based network, as a transformative solution. Simulations in the CARLA Simulator …

Harnessing Multimodal Sensory Feedback: An Exploration Of Rhythmic Asymmetric Cues In Gait Rehabilitation, Scott J. Bartlett Jr.

USF Tampa Graduate Theses and Dissertations

Stroke remains a leading cause of long-term disability, with survivors often facing challenges in mobility, particularly gait asymmetry. This adversity not only diminishes the quality of life but also imposes substantial socioeconomic burdens. Current rehabilitation methods are somewhat effective yet exhibit a dire need for augmentation to better address gait abnormalities. The novel introduction of Auditory Rhythmic Asymmetric Cues, Tactile Rhythmic Asymmetric Cues, and their simultaneous combination (A-RAC, T-RAC, and AT) offers a fresh perspective toward gait rehabilitation, aimed at taking steps to alleviate the adversities borne by stroke survivors. This study provides a thorough investigation of these asymmetric cues, …