Engineering Commons^™

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 …

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 …

Alpha Synuclein: A Therapeutic Target And Biomarker For Parkinson’S Disease, Max Chase

USF Tampa Graduate Theses and Dissertations

Parkinson’s Disease is the second most common neurodegenerative disease after Alzheimer’s Disease, and the most common motor disorder. In fact, nearly a third of those with AD have PD. A major hallmark of PD is the appearance of Lewy Bodies, proteinaceous cytoplasm inclusions, that build up and spread throughout the CNS in a prion like fashion. The major component of these Lewy Bodies is a protein called alpha-synuclein. Alpha-syn is a 14kDa protein made of 140 amino acids and found in the presynaptic ends of CNS neurons, acting as a chaperone and regulator. The protein is also found in the …

Stability Analysis Of Delay-Driven Coupled Cantilevers Using The Lambert W-Function, Daniel Siebel-Cortopassi

USF Tampa Graduate Theses and Dissertations

A coupled delay-feedback system of two cantilevers can yield greater sensitivity than that of asingle cantilever system, with potential applications in atomic force microscopy. The Lambert W-function analysis concept for delay differential equations is used to more accurately model the behavior of specific configurations of these cantilever systems. We also use this analysis concept to find parameters which yield stability for greater parameter ranges, of the delay differential equations. The Q factor, or quality factor, is the ratio of energy stored in the system, to the energy lost per fixed oscillation/movement cycle. Having stability of the cantilevers corresponds to the …

A Model-Based Fault Diagnosis In Dynamic Systems Via Asynchronous Motors System Identification Or Testing, And Control Engineering Observers, Kenelt Pierre

USF Tampa Graduate Theses and Dissertations

Induction machines are the workhorse of many military and commercialtypes of equipment. They are asynchronous machines referred to in this dissertation as induction motors. They are widely used due to their reliability in Naval Unmanned Systems like Remotely Operated Vehicles (ROV), Unmanned Untethered Underwater Vehicles (UUV), Autonomous Undersea Vehicles (AUV), and platforms like Missiles and Satellites. These induction motors are mainly controlled using variable speed drive functions, i.e., thrusters, propellers, and actuators. Though they are very robust, to harness the full technical benefits of induction motors, state-of-the-art drivers or controllers must be used to control such motors.

In model-based fault …

Magnetic And Structural Effects In Interfacial Magnetism: Molecular Magnets And Ferrimagnetic Alloys, Jenae E. Shoup

USF Tampa Graduate Theses and Dissertations

Magnetic thin films are important for technological applications such as giant magnetoresistance,spin valves and magnetic tunnel junctions. A key feature for these applications to be possible is the interface between two materials. We will be studying two types of thin film magnetism; interfaces between molecular carbon, C60, and non-magnetic/ferromagnetic material and two layers of ferrimagnetic rare earth/ transition metal alloys (RE/TM) that have similar composition to engineer a magnetic tunable interface.

One of the most unexpected spin-related properties of C60 is the emergence of room-temperature ferromagnetism in multilayer films of C60 and non-ferromagnetic transition metals such as Cu or Mn …

Block Copolymer Directed Self-Assembly: Exploring The Efficacy Of Applications In Semiconductor Fabrication, Jakin Bryce Delony

USF Tampa Graduate Theses and Dissertations

Over the course of the past 80 years, semiconductor devices have become increasingly ubiquitous in everyday life.From constructing mainframes that encompassed entire rooms during the 1940s, to inventing personal computers in the 1980s, to developing progressively faster smartphones and wearable technology in the 2010s, the primary driving force behind the Digital Revolution has been increasing transistor counts, and thus computing power, via incremental improvements in optical lithography. In 1965, Intel co-founder Gordon Moore boldly predicted that the transistor density of semiconductor devices would double approximately every 18-24 months. While this prediction -- now colloquially referred to as Moore's Law -- …

High-Risk Traffic Crash Pattern Recognition And Identification Using Econometric Models And Machine Learning Models, Runan Yang

USF Tampa Graduate Theses and Dissertations

Roadway crashes have become a major cause of human deaths and injuries and caused much economic damage. According to World Health Organization (WHO), about 1.35 million people died in traffic crashes and over 50 million people injured from traffic crashes in the year of 2016 (World Health Organization, 2020). Nationally, in the U.S., the latest decade witnessed an increase of over 10% in traffic fatalities (National Highway Traffic Safety Administration (NHTSA), 2019). Similarly, in state of Florida, the fatal crashes increased by 4.62% from 2019 to 2020 (Florida Department of Highway Safety and Motor Vehicles, 2021). To prevent injuries and …

On The Reliability Of Wearable Sensors For Assessing Movement Disorder-Related Gait Quality And Imbalance: A Case Study Of Multiple Sclerosis, Steven Díaz Hernández

USF Tampa Graduate Theses and Dissertations

Approximately 33 million American adults had a movement disorder associated with medication use, ear infections, injury, or neurological disorders in 2008, with over 18 million people affected by neurological disorders worldwide. Physical therapists assist people with movement disorders by providing interventions to reduce pain, improve mobility, avoid surgeries, and prevent falls and secondary complications of neurodegenerative disorders. Current gait assessments used by physical therapists, such as the Multiple Sclerosis Walking Scale, provide only semi-quantitative data, and cannot assess walking quality in detail or describe how one’s walking quality changes over time. As a result, quantitative systems have grownas useful tools …

Exploring Magneto-Excitons In Bulk And Mono-Layer Semiconductors Using Non-Linear Spectroscopy Techniques, Varun Mapara

USF Tampa Graduate Theses and Dissertations

The research in two-dimensional (2D) materials has evolved from ``traditional" quantum wells based on group III-V and II-VI semiconductors to atomically thin sheets of van der Waals materials such as 2D semiconducting Transition Metal Dichalcogenides (TMDs). These 2D materials remain a stimulating field that continues to introduce new challenges. From both a fundamental physics and technological perspective, magneto-optical spectroscopy has been an essential tool in this research field. TMDs, for example, pose the challenge of characterizing their spin-valley-resolved physics and deriving implications in quantum computation and information research. With the discovery of valley Zeeman effects, the spin-valley physics of TMDs …

Assessment Of Scoured Bridges Subjected To Vessel Impact Using Nonlinear Dynamic Analysis, Amir S. Irhayyim

USF Tampa Graduate Theses and Dissertations

Scour has been the number one cause of bridge failure in the United States with an average of 22 bridges collapsing or being closed owing to severe deformation each year [1]. This work attempts to deal with two important issues: (1) Potential bridge failures during the co-occurrence of scour and ship impact; (2) Incorporating IDA analysis to predict bridge responses based on barge and collision parameters, and to generate fragility curves to predict the probability of exceedance damage states.

For bridges, flooding is considered the most threatening hazard. According to the National Bridge Inventory (NBI) [2], 500,000 out of 615,000 …

Formation Of Trihalomethanes During Chlorination At South Cross Bayou Advanced Water Reclamation Facility, Pinellas County, Florida, Ian Grabo

USF Tampa Graduate Theses and Dissertations

South Cross Bayou Advanced Water Reclamation Facility (SCB) in Pinellas County, Florida, recently had a spike in effluent concentrations of bromodichloromethane (BDCM) and dibromochloromethane (DBCM) above the regulated limits, due to relying fully on chlorination instead of a combination of chlorination and ultraviolet light. The objective of this study was to determine the operating parameters most strongly affecting the formation of THMs. This was completed by analysis of long-term data sets obtained from SCB by multiple linear regression to create models describing THM formation. In addition, sampling of the chlorine contact chamber (CCC) was done to determine the effects of …

Estimating The As-Placed Grout Volume Of Auger Cast Piles, Tristen Mee

USF Tampa Graduate Theses and Dissertations

Augered Cast-in-Place (ACIP) piles are a geotechnical foundation element increasingly used to support large publicly funded structures as an alternative to drilled shafts or driven piles. ACIP piles are constructed by drilling an excavation to the full length of the designed pile with a continuous flight auger. Grout (cement, sand, and water mixture) is then pumped through the hollow auger stem to begin grouting the excavation. After establishing an initial head pressure, the auger is slowly extracted while the remainder of the pile is grouted. Once the auger is completely removed, the steel reinforcement cage is lowered into the grouted …

Carbon Diversion, Partial Nitritation/Anammox Enrichment, And Ammonium Capture As Initial Stages For Mainstream Ion Exchange-Deammonification Process, Sheyla Chero-Osorio

USF Tampa Graduate Theses and Dissertations

Eutrophication is a concerning environmental problem worldwide that results in algae blooms, oxygen depletion, damages to aquatic life and public health, water quality issues, and loss of aesthetics in water reservoirs. Nutrient (e.g., nitrogen and phosphorus) discharges from wastewater, agricultural, urban, and residential runoff promote eutrophication in receiving water bodies. In terms of nitrogen removal, conventional biological nitrogen removal (BNR) is a common technique used in many wastewater treatment plants (WWTP). However, BNR requires aeration for nitrification and organic carbon input for denitrification. In WWTP, the aeration represents a considerable investment in terms of energy costs. Recent technologies involve applying …

Analyzing Decision-Making In Robot Soccer For Attacking Behaviors, Justin Rodney

USF Tampa Graduate Theses and Dissertations

In robotics soccer, decision-making is critical to the performance of a team’s SoftwareSystem. The University of South Florida’s (USF) RoboBulls team implements behavior for the robots by using traditional methods such as analytical geometry to path plan and determine whether an action should be taken. In recent works, Machine Learning (ML) and Reinforcement Learning (RL) techniques have been used to calculate the probability of success for a pass or goal, and even train models for performing low-level skills such as traveling towards a ball and shooting it towards the goal[1, 2]. Open-source frameworks have been created for training Reinforcement Learning …

Effects Of Downdrag On Pile Performance, Malaak Omelia Araujo

USF Tampa Graduate Theses and Dissertations

All soils settle under the weight of newly constructed embankments. In the case of MSE wall-type embankments, piles are driven prior to embankment construction. Under the weight of the newly constructed embankment, the soil surrounding the piles may settle more than the piles themselves. This downward movement potentially drags the piles down and induces a force within the pile known as downdrag. The research on the downdrag phenomenon involving cohesionless granular soils is sparse, thus the focus of this study is to investigate the effects of downdrag on pile performance driven in Florida sandy soils. A site consisting of soil …

Techno-Economic And Sustainability Analysis Of Renewable Natural Gas (Rng) Production, Eesha Bhattacharjee

USF Tampa Graduate Theses and Dissertations

Natural Gas (NG) is one of the major sources of energy currently used in the United States. Its major applications include generating electricity, domestic, and industrial heating purposes and as a transportation fuel. The largest component of NG is methane, and it contains trace amounts of hydrocarbons, some CO2 and water vapor.

Biogas (produced by anaerobic digestion (AD) of biomass) upgraded to have high purity methane (often termed as biomethane or renewable natural gas) can be used as an alternative to NG. The upgrading techniques may include CO2 separation from the biogas stream or via to a methanation facility where …

Bayesian Network-Based Diagnostic Support Tool With Limited Point-Of-Care Ultrasound For Work-Related Elbow Injuries, Cristina Maria Franceschini Sánchez

USF Tampa Graduate Theses and Dissertations

The upper extremity is commonly injured at the workplace, frequently involving the elbow. Currently, there are not many diagnostic support tools for elbow injuries. Developing a clinical decision support tool would allow for narrowing differential diagnoses and guide management steps in a timely and cost-effective manner. In a descriptive retrospective cohort study, 85 non-contrast elbow MRIs were obtained from a large Workers Compensation insurer database. MRIs were either (a) greater than 2 weeks after first clinic visit, or (b) more than 6 weeks after injury, but (c) not more than 3 months after injury. A Bayesian network-based diagnostic support tool …

The Impact Of Land Use Change On Hydrology Using Hydrologic Modelling And Geographical Information System (Gis), Nattachan Luesaksiriwattana

USF Tampa Graduate Theses and Dissertations

Surface and groundwater conditions in west-central Florida are highly interactive, with shallow water table and sandy soil. Land use types including forests, agricultural areas, and urbanization affect water resources differently. Change in land use, associated with expanding the urban environment to support human needs, significantly impacts surface water infiltration and runoff characteristics. Construction of infrastructures such as buildings and housing can result less water to infiltrate through the soil, with increased surface water runoff and decline in evapotranspiration. A computerized hydrologic model, Hydrological Simulation Program-FORTRAN (HSPF), couple to a spreadsheet groundwater model and a Geographical Information System (GIS) were applied …

Secure Hardware Constructions For Fault Detection Of Lattice-Based Post-Quantum Cryptosystems, Ausmita Sarker

USF Tampa Graduate Theses and Dissertations

The advent of quantum computers and the exponential speed-up of quantum computation will render classical cryptosystems insecure, as that can solve current encryptions in minutes, resulting in a catastrophic failure of privacy preservation and data security. Through the standardizing of quantum-resistant public-key cryptography algorithms, the National Institute of Standards and Technology (NIST) is evaluating potential candidates to thwart such quantum attacks. In this dissertation, countermeasures against fault attacks are proposed to secure various lattice-based cryptosystems, one of the most promising post-quantum cryptosystems. Fault detection architectures for crucial building blocks of lattice-based cryptosystems, i.e., number-theoretic transform, ring polynomial multiplication, and ring …

Humanoid Robot Motion Control For Ramps And Stairs, Tommy Truong

USF Tampa Graduate Theses and Dissertations

Humanoid robot research and development have been an ongoing effort since the 1900sand can be broken down to two problems. A mechanical problem, getting a humanoid robot to move human-like or a software problem, getting a humanoid robot to behave human-like. These problems of moving and behaving human-like can be often solved using control theory as research advances. For the premise of this research, we explore how to balance and walk on non-flat terrain for the humanoid robot Darwin-Op. Since the focus was on the control theory, the vision control to detect the non-flat terrain was a side objective. The …

Assistive Technologies For Independent Navigation For People With Blindness, Howard Kaplan

USF Tampa Graduate Theses and Dissertations

The necessity for individuals to navigate from location to location is essential to daily life. The majority of humans use sight as the main source for determining how to move through their environment. However, there is a large population of people who are either blind or living with low vision. Based on a 2017 National Health Survey there are around 27 million adult Americans that have experienced vision loss (National Center for Health Statistics, 2017). According to the Eye Diseases Prevalence Research Group there are 3.4 million Americans 40 years and older that are legally blind or visually impaired (EDPRG, …