Engineering Commons^™

Assessment And Prevention Of Bacterial Regrowth In Stored Household Water In Eastern Coastal Madagascar, Lauren Judah

USF Tampa Graduate Theses and Dissertations

As of 2020, diarrheal diseases were the leading cause of death in Madagascar. A major cause of diarrheal illness is contaminated water, and one crucial aspect of preventing contaminated water is safe household storage. Bacterial regrowth between point-of-collection and household storage has been well established in literature. A frequently implicated source of regrowth is the storage container’s biofilm, which is a community of varying bacteria enclosed in a “slimy” extracellular polymeric substance that forms on surfaces in wet environments and anchors bacteria to those surfaces. The overall goal of this thesis was to quantify and control bacterial regrowth in household …

Accelerating Multiparametric Mri For Adaptive Radiotherapy, Shraddha Pandey

USF Tampa Graduate Theses and Dissertations

MR guided Radiotherapy (MRgRT) marks an important paradigm shift in the field of radiotherapy. Superior tissue contrast of MRI offers better visualization of the abnormal lesions, as a result precise radiation dose delivery is possible. In case of online treatment planning, MRgRT offers better control of intratumoral motion and quick adaptation to changes in the gross tumor volume. Nonetheless, the MRgRT process flow does suffer from some challenges that limit its clinical usability. The primary aspects of MRgRT workflow are MRI acquisition, tumor delineation, dose map prediction and administering treatment. It is estimated that the acquisition of MRI takes around …

Adaptive Multi-Scale Place Cell Representations And Replay For Spatial Navigation And Learning In Autonomous Robots, Pablo Scleidorovich

USF Tampa Graduate Theses and Dissertations

Place cells are one of the most widely studied neurons thought to play a vital role in spatial cognition. Extensive studies show that their activity in the rodent hippocampus is highly correlated with the animal’s spatial location, forming “place fields” of smaller sizes near the dorsal pole and larger sizes near the ventral pole. Despite advances, it is yet unclear how this multi-scale representation enables navigation in complex environments.

In this dissertation, we analyze the place cell representation from a computational point of view, evaluating how multi-scale place fields impact navigation in large and cluttered environments. The objectives are to …

Improving Wireless Networking From The Learning And Security Perspectives, Zhe Qu

USF Tampa Graduate Theses and Dissertations

Due to the high development of wireless networking and artificial intelligence, most of the data are generated from mobile devices, which distribute in different environments. As such, how to improve the performance of machine learning-based networking and its security should be carefully considered. To reduce the communication burden and protect private information from users, Federated Learning (FL) is a possible solution for learning-based wireless networking. Although FL achieves much success until now, it also remains some specific issues to be solved. In this dissertation, we propose two FL wireless networking frameworks and discuss two potential security issues.

In the FL …

4d Printing Of Smart Hydrogel Scaffold To Program Neural Stem Cell Differentiation, Omar Khater

USF Tampa Graduate Theses and Dissertations

Injuries like Traumatic brain injuries (TBI) and Spinal cord injuries (CSI) areconsidered one of the biggest challenges in the medical sector as there is no specific treatment for these injuries and the medical intervention on these injuries is restricted to reducing the pain and removing the damaged human parts. One of the helpful and most effective treatment methods for these injuries involve neural tissue regeneration in the area of the injury. The main issue when trying to treat such injuries is that neural tissues are often unable to regenerate by themselves and require outer human intervention to differentiate. Biomedical scaffolds …

Elemental Sulfur And Metal Sulfide Minerals For Autotrophic Denitrification: Applications To Aquaculture, Groundwater Treatment, And Domestic Wastewater Treatment, Erica Amah Dasi

USF Tampa Graduate Theses and Dissertations

Nutrient pollution of waterways, from excess N and P, is a global concern that results in harmful impacts the environment, human health, and aquatic animals. This dissertation harnesses sulfur autotrophic denitrification to remove nutrients from groundwater, domestic wastewater, and wastewaters produced from marine recirculating aquaculture systems (RAS). Part 1 evaluates the denitrification performance of woodchips and elemental sulfur in cyclic denitrification filters (WS-CDFs) integrated into marine RAS operated under saline conditions. Part 2 investigates the use of metal sulfide minerals, with and without oyster shells, for supporting nutrient removal from groundwater in batch reactors. Part 3 assesses …

Healthcare Iot System And Network Design, Halil Ibrahim Deniz

USF Tampa Graduate Theses and Dissertations

The developing IoT concept offers many opportunities to service providers in the medical field. However, the functionality of the developed systems is increasing day by day, and it brings many different problems. One of the most important problems is the transmission of biomedical data of real-time monitoring systems to the medical server with the least delay. Network architectures are changing to meet the changing needs of densely connected devices, and “computing at the edge” is the new architectural approach emerging in IoT networks. This architecture is more dynamic than computation in the cloud because it enables data processing at each …

Deep Learning And Feature Engineering For Human Activity Recognition: Exploiting Novel Rich Learning Representations And Sub-Transfer Learning To Boost Practical Performance, Ria Kanjilal

USF Tampa Graduate Theses and Dissertations

A significant gap exists in our knowledge of how domain-specific feature extraction compares to unsupervised feature learning in the latent space of a deep neural network for a range of temporal applications including human activity recognition. This dissertation aims to address this gap specifically for human activity recognition using acceleration data. To ensure reproducibility, we use two publicly available datasets, UniMiB-SHAR and ExtraSensory, with a well-established history in the human activity recognition literature. We methodically analyze the performance of 64 different combinations of i) learning representations (in the form of raw temporal data or extracted features), ii) traditional and modern …

Stability And Interaction Analysis Of Inverter-Based Resources In Power Grids, Li Bao

USF Tampa Graduate Theses and Dissertations

The increasing penetration of inverter-based resources (IBRs) introduces some unexpected dynamic issues, including low-frequency oscillations. To investigate these phenomenon, a laboratory-scale grid-following voltage-source converter (VSC) system is implemented to demonstrate weak grid oscillations. Grid-following control is applied in VSC to provide active power, reactive power or ac voltage control. The test bed is also replicated in electromagnetic transient (EMT) simulation environment (MATLAB/SimPowerSystems) for benchmark purpose. Case studies are carried out to demonstrate low-frequency oscillations under real power/ac voltage or real power/reactive power control. An analytical model is carried out to examine the stability condition and compared with EMT or hardware …

Aqueous Humor Dynamics And Compound Action Potentials In The Anesthetized And Conscious Freely Moving Rat, Youssef Mohamed

USF Tampa Graduate Theses and Dissertations

Vision is dependent on the proper functioning of many intricate components of the eye. Aqueous humor dynamics function to keep the eye inflated at the right pressures and nourish avascular tissue in the eye while properties of the corneoscleral shell dictate how dynamic changes in volume and pressure affect tissue at the optic nerve head. Retinal ganglion cells exit the globe at the optic nerve head and carry all of the visual information to the brain for perception of visual stimulus. In this dissertation, we aim to present a lumped parameter model of the eye that can accurately describe the …

A Protein-Based Therapeutic Combination For The Treatment Of Hard-To-Heal Wounds, Graham L. Strauss

USF Tampa Graduate Theses and Dissertations

Chronic wounds present many clinical challenges in relation to the successful treatment and closure of the damaged tissue. Most current treatment methods focused on one or two aspects to drive wound closure, while most chronic wounds are multifactorial environments with many of those dependencies relying on the termination of one another to effectively gain tissue construction, closure, and full skin thickness and composition. Natural wound healing processes allude to potential biologics that can impede the chronic breakdown of tissue, while restoring deposition of new tissue, and effectively leading to a healed wound. Proteases secreted by the body’s immune system lay …

Large Area Projection Sintering Of Semicrystalline Polymers And Part Analysis Of The Printed Specimens, Taranjot Kaur

USF Tampa Graduate Theses and Dissertations

As the requirements posed to products have increased in recent years. The trend towards individualized serial products steps up the need for respective manufacturing techniques to be more and more flexible. Conventional techniques of serial production, such as injection molding, are unable to fully meet the requirements of this trend. Additive manufacturing techniques generate components directly from a CAD data set while requiring no specific mold, producing minimal waste, and reaching satisfactory geometric accuracy. This is how, as opposed to conventional techniques, they comply with these increased demands to processing technology. Over the last two decades, the research community has …

Modified Biosand Filtration Using Aluminum Hydroxide Filter Media To Enhance Fluoride Removal, Joshelyn Guimaray

USF Tampa Graduate Theses and Dissertations

There are over 20 countries whose citizens consume groundwater containing high levels of fluoride, including Nigeria, Mexico, India, China, and Ghana, which all have major health crises when it comes to the safety of their drinking water. Minerals like fluorite contain fluoride which is often found in groundwater aquifers. The minerals release fluoride into the groundwater. Per the World Health Organization (WHO) standard, the maximum contaminant limit for fluoride consumption should be less than 1.5 mg/L. Chronic exposure of elevated levels of fluoride can cause people to suffer debilitating health effects, such as dental and skeletal fluorosis. Dental fluorosis causes …

Mm-Wave Reconfigurable Antenna Arrays, Phase Shifters And Beamforming Networks With Reduced Hardware Complexity Using Integrated Microfluidic Actuation, Jonas J. Mendoza Sandoval

USF Tampa Graduate Theses and Dissertations

Microfluidically reconfigurable radio-frequency (RF) devices, in general, are found attractive for low-loss, wide-frequency tunability, low hardware complexity, and high-power-handling capabilities. More recently, microfluidic actuation has also been proposed as an alternative to semiconductors and micro-electromechanical systems-based approaches to realize new and compact reconfigurable devices operating in mm-Wave bands. This research expands the knowledge base on low-loss and compact mm-Wave reconfigurable devices. The reconfiguration approach relies on utilizing a microfluidically actuated selectively metalized plate (SMP) within proximity of the RF device to alleviate the practical issues arising from the traditional usage of liquid metals in microfluidically reconfigurable devices.

The first novel …

A Convergent Approach To Aqueous Lead (Pb) Mitigation Of A Supplemental Self-Supply Shallow Groundwater Source Accessed By Handpumps In Madagascar, Adaline Marie Buerck

USF Tampa Graduate Theses and Dissertations

The World Health Organization (WHO) has consistently listed lead (Pb) as one of the ten chemicals of major public health concern. Though the toxic nature of lead has been known since the 20th century it is still utilized in a wide variety of products due to its favorable properties. Exposure to lead still accounts for approximately 900,000 deaths annually and disproportionately impacts those in low- and middle-income countries (LMIC) due to a variety of reasons such as poverty, malnutrition, and lack of knowledge on the toxic nature of lead. Lead exposure routes include air, soil, dust, diet, and water. Though …

Passive Radiative Cooling By Spectrally Selective Nanoparticles In Thick Film Nanocomposites, David Allen Young

USF Tampa Graduate Theses and Dissertations

Passive cooling of buildings is a benefit to society since no energy input is required for space cooling which reduces electricity consumption, fossil fuel burning, and greenhouse gas emissions. When a passive cooling technology radiates heat from the earth through the atmospheric windows to space higher levels of cooling power are possible -- this phenomenon is classified as passive “radiative” cooling. Spectrally selective surface coatings provide radiative cooling to lower surface temperatures by reflecting most solar radiation, while emitting infrared radiation at wavelengths between 8-13 μm through the primary atmospheric window to the cold of space. Multiple applications of radiative …

An Integrated Approach For Dynamic Process Modeling And Optimization Of Wastewater Treatment Facilities, Komal Rathore

USF Tampa Graduate Theses and Dissertations

The subareas of process systems engineering including process modeling, simulation, and optimization are becoming progressively substantial for understanding processes, making decisions, improving efficiency, and complying with stricter environmental and safety legislation. Additionally, the availability of user-friendly flowsheet simulators and computational resources with the current trend of data collection and analysis has allowed for a more accurate representation of complex processes such as wastewater treatment systems. Despite all the progress in the areas of process modeling and simulation, the first-principle mechanistic models for wastewater treatment processes are at best employed during the design stage, and therefore, not used optimally for day-to-day …

Explainable And Cooperative Autonomy Across Networks Of Distributed Systems, Peter Joseph Jorgensen

USF Tampa Graduate Theses and Dissertations

Large networks of complex systems-of-systems are commonplace and evermore present in both mundane and extraordinary facets of human existence. From the exponential growth of connectivity via the internet and other information networks, to the miniaturization of computers and sensors, to cross-domain sensor and communication networks, these networks of distributed systems-of-systems (NDSS) present incredible benefits and challenges. Autonomy is perhaps the most important and most difficult to achieve enabling technology for efficient performance of the NDSS. Giving each individual agent in a network the ability to manage its internal state in dynamic operating environments and in pursuit of multiple complex and …

Fragmentation Of Chemically Herded Oil Slicks By Obstacles: Visualizations, Flow Measurements, And Spatial Distributions, Ali Alshamrani

USF Tampa Graduate Theses and Dissertations

Chemical herders are a promising technique for treatment of oil spills in icy waters at high latitudes. However, obstacles on the water surface such as floating ice affects or interferes with all spill response countermeasures including chemical herder operations by fracturing the contracting oil slick and trapping small oil patches. Chemical herders are likely to be especially useful in containing oil spills in remote, ice-infested Arctic waters, where using booms to contain an oil slick is difficult. Much of the previous research into chemical herder has focused on the effectiveness of different types of chemical herder agents to thicken oil …

Development And Analysis Of Green Pathways For Biphasic Extraction At High Pressure, Kyle L. Cogswell

USF Tampa Graduate Theses and Dissertations

Technological advancements over the last century have allowed for advancements not only in science and engineering but medicine as well. The use of supercritical fluids for processing continues today after its initial boom in the latter part of the last century; often being paired with co-solvents to extend the range of use for this technique. Supercritical fluid extraction may be paired with pressurized warm water extraction to yield a new intensified process for biphasic extractions that improves efficiency and reduces waste. This combination may be used to replace sequential extraction processes or supercritical extraction processes that make use of organic …

Evaluation Of Aluminum Dissolution, Current Density, And Pitting Patterns During Electrocoagulation, Monica Castro Carias

USF Tampa Graduate Theses and Dissertations

Electrocoagulation (EC) is a sustainable water treatment process involving the generation of coagulants on-site through the application of a voltage on metal (usually aluminum or iron alloys). The factors that impact EC system performance have been well researched, however further research is needed on the factors that impact anodic dissolution of aluminum electrodes, especially when the technology is transferred to full-scale applications. Electrode fouling is one of the factors that can impact dissolution of the anode during EC due to the formation of a protective oxide/hydroxide layer on the electrode surface. Previous studies have addressed electrode fouling by reversing polarity, …

Improved Performance Of Silica-Supported La0.5Ba0.5Feo3 In The Reverse Water Gas Shift - Chemical Looping Process For Carbon Dioxide Reduction – A Density Functional Theory Study, Jiawei Guo

USF Tampa Graduate Theses and Dissertations

Global warming is increasingly obvious, and the reduction of greenhouse gases is an effective way to heal. Increasing the efficiency of catalysts that is applied in the industry can significantly reduce the emission of greenhouse gases. Reverse water gas shift chemical looping (RWGS-CL) is a promising reaction to convert CO2 to CO. La0.5Ba0.5FeO3 (LBF) is a good candidate for RWGS-CL, which shows increased conversion yield when supported on silica. This research focuses on identifying the mechanism of RWGS-CL via silica-supported LBF by exploring the oxygen vacancy formation energy (EO-vac). Density Functional Theory (DFT) is a powerful computational method to solve …

Degradation Performance Modeling And Optimal Maintenance Planning Of Deteriorating Critical Infrastructures, Hung Q. Nguyen

USF Tampa Graduate Theses and Dissertations

Serving as the backbone of the nation’s economy, a large and growing number of deteriorating critical infrastructures, such as transportation and water infrastructures, are underperforming, aging, becoming structurally deficient, and must be repaired or replaced. Due to the influence of a variety of factors (e.g., material structure, design, operation, and environmental conditions) at different phases of lifecycle and the costly data acquisition process, field degradation of deteriorating infrastructures is highly uncertain with limited degradation data. The co-location and spatial proximity between many infrastructures, such as road and water infrastructures, further makes them physically and operationally interdependent. The sheer deterioration of …

Simulating Flood Control In Progress Village, Florida Using Storm Water Management Model (Swmm), Azize Minaz

USF Tampa Graduate Theses and Dissertations

Flooding is a natural event caused by heavy rains, melting snow, high tides, and anthropogenic impacts such as channel clogging, improper land use, and deforestation. In this study, the strategies for controlling flooding seek to establish flood prevention systems by implementing grey infrastructure and green infrastructure practices. The main objective of this thesis is to analyze the study area, Progress Village Neighborhood in Delaney Creek Watershed, regarding flood risk and flood mitigation techniques. The analysis was performed using EPA SWMM 5.1 and Arcmap 10.7.1. The study used design storms,10-years 24 hours and 25-years 24 hours, to analyze flood risk in …

Hybrid Rans-Les Hemolytic Power Law Modeling Of The Fda Blood Pump, Joseph Tarriela

USF Tampa Graduate Theses and Dissertations

This study applies the SBES and IDDES hybrid RANS-LES turbulence models along with the K-ω SST model to four flow conditions of the FDA blood pump. Validation of all three turbulence models show good agreement with experimental pressure and velocity fields. Evaluation of turbulent kinetic energy fields for the hybrid models show 80-90+% of kinetic energy is resolved in the rotor and diffuser regions of the pump. Hemolysis power law models were evaluated using the commonly used von Mises stress and additional energy dissipation stress (EDS). Results show viscous and Reynolds stresses computed with the K-ω SST under predict and …

Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer

USF Tampa Graduate Theses and Dissertations

This is a two-part thesis with the overall investigation technique being electrochemical impedance spectroscopy (EIS). In the first part, EIS is used to estimate the layer thickness of anodized aluminum oxide. This required the development of an appropriate electrical circuit model; that with parameters that correspond to physical properties of the oxide. In this work, it was found that for thicker oxides of which the outer porous layer is greater than 12 microns, impedance may be used to estimate the outer layer thickness. However, further research is required to understand the role of outer porous layer structure on the impedance …

Computational Methods For Solving The Combinatorial Optimization Problems In Transportation, Xufei Liu

USF Tampa Graduate Theses and Dissertations

This dissertation discusses three transportation problems. The first problem is a bi-level optimization problem that simultaneously optimizes facility locations and network design in hazardous materials transportation. In the upper level, the leader intends to reduce the facility setup cost and the hazmat exposure risk, by choosing facility locations and road segments to close for hazmat transportation. When making such decisions, the leader anticipates the response of the followers who want to minimize the transportation costs. A robust optimization approach with multiplicative uncertain parameters and polyhedral uncertainty sets is applied to deal with the uncertain risk and demand.

The second problem …

Exploration Of Energy Efficient Computing For Data-Intensive Applications, Md Adnan Zaman

USF Tampa Graduate Theses and Dissertations

The recent surge of data-intensive applications has stretched the performance and energy limit of today’s traditional computing system. The massive amount of data generated by data-intensive applications is not processed at the same speed due to bandwidth mismatch between the faster processing unit and slower memory. Memory access and communication bandwidth can be identified as the primary bottlenecks. Consequently, these two bottlenecks make up most of the total energy consumption. In light of this, we explore energy-efficient computing for data-intensive applications. We examine different aspects of two computing systems, such as in-memory computing and AI-enabled edge computing, more popularly known …

Security And Privacy Enhancing Technologies In The Deep Learning Era, Gamage Dumindu Samaraweera

USF Tampa Graduate Theses and Dissertations

Our search queries, online purchase transactions, the videos we watch, and our movie preferences are a few types of information collected and stored daily. This private data collection happens within our mobile devices and computers, on the streets, and in our homes, most of the time even without our consent. Nevertheless, advances in artificial intelligence (AI) in the big data era have increased the capability to capitalize on and benefit from the collection of this private data. Such private data is being used for various machine learning (ML) applications in different domains, such as marketing, insurance, financial services, mobility, social …

Effects Of Slurry Type On Drilled Shaft Strength, Cesar Quesada Garcia

USF Tampa Graduate Theses and Dissertations

The main objective of this research is to identify how the strength of drilled shafts is affected by the use of various types of drill slurry. When concrete is placed in drilled shafts it flows out radially and a laitance interface forms creating a crease on the backside of the reinforcement cage due to the laitance trapped in concrete flowing around the rebar. This can cause concrete to not fully encapsulate the steel making the shafts prone to corrosion and the strength of the cover concrete is locally reduced. Over the past 9 years 58, 42-inch diameter shafts have been …