Engineering Commons^™

Metal Oxide Sensor Array Test Bed Prototype For Diagnostic Breath Analysis, Tiffany C. Miller

USF Tampa Graduate Theses and Dissertations

Detection of specific target biomarkers is a critical step for electronic nose technologies in breath analysis. Electronic nose technologies have been successfully demonstrated in the air quality, meat processing, and the citrus industries, as well as cancer clinical trials. The novel design, assembly, and implementation of a test bed prototype of an electronic nose system is introduced in this Dissertation. To verify the feasibility of a test bed prototype design, a Corona Virus Disease 2019 (COVID-19) breath simulation mixture of alcohol, acetone, and carbon monoxide was presented to the test bed prototype in the laboratory. The COVID-19 breath simulation mixture …

Alternative Approaches To Protect Sensory Inner Ear Tissue Against Cisplatin-Induced Ototoxicity, Nicole K. Febles

USF Tampa Graduate Theses and Dissertations

Sensorineural hearing loss (SNHL) is a prevalent neurodegenerative disorder often involving permanent damage and loss to the inner ear’s mechano-sensory hair cells and spiral ganglion neuron fibers. Significant causes of SNHL are ototoxic drugs, environmental factors, loud noises, and continuous wear with age. A successful but ototoxic chemotherapeutic known as Cisplatin often damages auditory hair cells via mitochondria dysfunction, DNA fragmentation, and cellular death through apoptosis. Despite the high prevalence of SNHL, there currently is no FDA-approved prevention or cure. Thus, auditory and cancer researchers have investigated various individual otoprotective agent preventions with limited success. This dissertation used a novel …

Data-Driven Studies On Social Networks: Privacy And Simulation, Yasanka Sameera Horawalavithana

USF Tampa Graduate Theses and Dissertations

Social media datasets are fundamental to understanding a variety of phenomena, such as epidemics, adoption of behavior, crowd management, and political uprisings. At the same time, many such datasets capturing computer-mediated social interactions are recorded nowadays by individual researchers or by organizations. However, while the need for real social graphs and the supply of such datasets are well established, the flow of data from data owners to researchers is significantly hampered by privacy risks: even when humans’ identities are removed, or data is anonymized to some extent, studies have proven repeatedly that re-identifying anonymized user identities (i.e., de-anonymization) is doable …

High Speed Switching For Plasma Based Electroporation, Shivangi Sharma

USF Tampa Graduate Theses and Dissertations

Ever since mankind has started identifying the diseases, extensive work has been done, and pathologies are written identifying the cure for them. As technology progressed, the development in the field of pathologies also did. Thus, finding innovative and efficient ways to get the ‘cure’. With the advancement in drugs, the delivery methods for these drugs also have advanced. One such delivery method is gene therapy. This method is beneficial when genes are to be used to prevent diseases.

Gene therapy has been proven effective for treating a wide range of conditions, such as cancer, heart diseases, and diabetes. Gene therapy …

Analysis And Modeling Of Strategic Interactions In Health Systems To Improve Patient Care Access, Jorge A. Acuña Melo

USF Tampa Graduate Theses and Dissertations

Affordable health care access that provides well-coordinated and high-quality services on time is a goal that governments and health organizations strive for. Regrettably, most countries deal with access problems that affect the population's health, such as long waiting lists for specialized medical services, overcrowding of emergency departments, and high health prices. In the present doctoral dissertation, I model and analyze the strategic interactions that inhabit the health system machinery to uncover possible structural problems that led to the aforementioned issues. The study involves operation research, data science, and game theory techniques to address the health care access predicament.

Each research …

Influence Of Coating Defects Within The Lock Seams On The Corrosion Performance Of Aluminized Steel Drainage Pipes, Mohammed Al Yaarubi

USF Tampa Graduate Theses and Dissertations

The electrochemical behavior of aluminized steel is investigated to determine the corrosion performance of coating deficiencies generated within the lock seams during the fabrication of aluminized steel corrugated pipe. Electrochemical techniques and visual and profilometric analysis are used to assess the ability of the aluminum and zinc coating to provide sufficient galvanic protection to the underlying steel in the presence of a crevice. Also, Crevice coupons and lock-seam samples were used in this investigation in different environmental conditions simulating natural water conditions to relate the corrosion rate with the level of protection that the coating will provide. In addition, a …

Development Of A Numerical Process Model For Adsorbent-Amended Constructed Wetlands, Lillian Mulligan

USF Tampa Graduate Theses and Dissertations

There is a need for alternative methods for municipal landfill leachate treatment as the high concentrations of pollutants in leachate interfere with processes at publicly owned treatment works (POTWs). Constructed wetlands (CWs) have been shown to be a sustainable alternative with good removal efficiencies for chemical oxygen demand (COD) and ammonia nitrogen (NH4+). The addition of an adsorbent media, such as zeolite and biochar, to CWs to further enhance removal efficiencies has been investigated in recent years. However, the long-term effects of zeolite and biochar addition to CWs is not well known. A model could be a useful tool to …

Flow Visualization And Aerosol Characterization Of Respiratory Jets Exhaled From A Mannequin Simulator, Sindhu Reddy Mutra

USF Tampa Graduate Theses and Dissertations

It is important to understand the airborne transmission of infectious diseases due to the COVID-19 pandemic. Physical experiments were conducted to understand the dispersion of aerosols emitted from a mannequin simulator replicating human tidal breathing through the nose and mouth with and without a protective face mask in an enclosed space. Flow patterns are observed via high-speed visualization, and the concentration and size distribution of the particles is measured as a function of distance from the mannequin using an optical particle sizer. Masks were shown to effectively reduce the horizontal dispersion of aerosol for both mouth and nose breathing. Further, …

Corrosion Propagation Of Stainless Steel Reinforced Concrete, Nelly Sofía Orozco Martínez

USF Tampa Graduate Theses and Dissertations

Structural durability is a growing concern in global infrastructure. The infrastructure report card released by the American Society of Civil Engineers (ASCE) indicates that approximately 9.1% of the total bridges in the United States were structurally deficient in 2016. In addition, it suggests that about 40% of the total bridges in the country are now 50 years or older. This issue becomes even more critical in structures exposed to aggressive environments such as marine structures. Thus, federal and regional efforts are now being directed towards infrastructural durability improvement to improve the long-term cost-efficiency of civil infrastructure.

Corrosion prevention strategies may …

Corrosion Durability Service Life Of Calcium Silicate-Based Reinforced Concrete, Carolina Páez Jiménez

USF Tampa Graduate Theses and Dissertations

Corrosion of reinforcing steel is a major area of study for assessing durability of reinforced concrete infrastructure. Conventional concrete infrastructure designs use ordinary Portland cement (OPC) as the primary cementitious material. However, the world's current challenge to achieve sustainable development requires the cement industry to reduce its environmental impact, as it is responsible for 8% of the anthropogenic CO2 emissions. Hence, a new type of cement has been developed. This novel calcium silicate cement (CSC) reduces the carbon dioxide emissions during its manufacturing process as compared to OPC, providing an environmentally-sound alternative for reinforced concrete fabrication.

Corrosion of steel reinforcement …

A Framework To Aid Decision Making For Smart Manufacturing Technologies In Small-And Medium-Sized Enterprises, Purvee Bhatia

USF Tampa Graduate Theses and Dissertations

The fourth industrial revolution or Industry 4.0 has changed today’s manufacturing scenario. The transition to smart manufacturing technologies has been evolving over the last few years and has recently accelerated due to the pandemic. The need to make manufacturing systems agile, adaptive, resilient, and robust has expediated the adoption and implementation of smart manufacturing technologies.

Despite the interest of manufacturers in smart manufacturing, the adoption rate has been slow due to the lack of decision-making tools that can provide a clear strategic roadmap for effective execution. Small and medium sized enterprises (SMEs) are especially slow in adoption due to the …

Sustainability Assessment Of A Pressure Retarded Osmosis System, Samar Al Mashrafi

USF Tampa Graduate Theses and Dissertations

Desalination has the potential to provide a stable supply of clean fresh water and meet the increasing water demands; however, this process does come with a few challenges such as high energy consumption, high energy cost, and a discharge of a highly concentrated brine. Pressure retarded osmosis (PRO) is a technology that could work as an efficient energy recovery technology for desalination since it can significantly reduce the energy consumption and dilute the brine before discharge. Studies have assessed the economic feasibility of PRO systems; however, these studies have not addressed the environmental sustainability of the systems. Thus, there is …

Transparent Planar Micro-Electrode Array For In-Vitro Electric Field Mediated Gene Delivery, Raj Himatlal Shah

USF Tampa Graduate Theses and Dissertations

Gene delivery is the process of delivering the modified gene into the human cell. There are two types of gene delivery depending on where the target cells are. The in-vivo gene delivery deals with delivering the altered genes into the cells while still in the host body. While another approach is to extract the cells from the host body, transfer the modified gene into cells and then put these cells back into the host body, this approach is called the ex-vivo method.

A vector is a carrier that carries the modified gene to the host cell or body. Hence, depending …

Assessing The Feasibility Of Microbially Managed Biological Filtration In U.S. Drinking Water Systems For Removal Of Contaminants Of Emerging Concern, Andrew J. Black

USF Tampa Graduate Theses and Dissertations

The future of water security in the U.S. is clouded by the progression of anthropogenic climate change and the increasing number of households unable to afford access to safe drinking water, while advances in detection and potential health risks of trace organic contaminants are constantly moving the water treatment finish line. There is a need for sustainable, economically feasible technology to provide the means to meet increasingly stringent water quality regulations while also ensuring current standards are met for all communities. Biologically active filtration, combined with an operational approach designed to optimize contaminant removal by the biofilm, may enable water …

Maximum Multiplicative Programming: Theory, Algorithms, And Applications, Payman Ghasemi Saghand

USF Tampa Graduate Theses and Dissertations

This dissertation presents three different contributions to an important class of optimization problems known as Multiplicative Programs (MPs). The first group of contributions contains the development and analysis of several multi-objective optimization-based based algorithms designed to find the optimal solution of Mixed Integer Linear MPs. As for the second group, the application of a special class of MPs in radiotherapy planning is presented. Finally, in the last group, a new technique for conducting the multiplication process in the objectives of MPs is presented. Using this technique, we introduce a family of novel solution methods that are capable of solving both …

Low-Cost Device For Laser Phacoemulsification: A Preliminary Study, Mitchell Harrah

USF Tampa Graduate Theses and Dissertations

The current gold standard of cataract removal surgery is phacoemulsification systems. These are divided based on the type of devices used; both are considered equal but with different delivery modes. These delivery methods are either acoustic or light-based. However, these devices pose two hurdles for impoverished areas: high costs and heavy resource usage. This thesis proposes a novel phacoemulsification system is based on the low-cost, off-shelf laser diodes that implement light-based phacoemulsification of cataracts. The system is tested for viability over two methods: finite element analysis and experimentation on various phantoms. Simulations on the device have occurred on the COMSOL …

Modeling, Control And Analysis Of Inverter-Based Generators In The Power Grids, Yangkun Xu

USF Tampa Graduate Theses and Dissertations

Nowadays, the inverter-based generators (IBGs) has been exponentially integrated into the power grid due to environment and energy saving concerns. However, the high penetration of low inertia IBGs brings new problems on the system stability. The main objectives of this dissertation are to: 1- carry out large-signal analysis to identify the stability issues and small-signal analysis to assess the stability of the power systems, and 2- provide a standard measuring procedure to identify the admittance of IBGs. In addition, investigation on a novel DC-based IBGs architecture is carried out. In this dissertation, one widely used IBG is investigated: Type-4 wind …

Data-Informed Decision Support To Improve Pediatric And Maternal Care Quality Under Medicaid Managed Care Settings, Hasan Symum

USF Tampa Graduate Theses and Dissertations

Over the last two decades, the United States has spent almost twice as much per person in healthcare compared to most other wealthy countries. However, this higher spending has not necessarily transformed into improved quality of care; According to World Health Organization reports, the US now ranks 39th for child health and wellbeing and worst in maternal care among developed nations. In terms of proportion of preventable hospital visits, low-risk cesarean sections, and avoidable maternal morbidity/death, the U.S. is among the highest compared with the peer nations. The prevalence of these adverse outcomes in pediatric and obstetric care is particularly …

Phasor Domain Modeling Of Type-Iii Wind Turbines, Mohammed Alqahtani

USF Tampa Graduate Theses and Dissertations

This dissertation research focuses on developing an accurate steady-state phasor model for Doubly Fed Induction Generator (DFIG)-based wind turbines (Type-III WTs). Unlike the classical synchronous or asynchronous generators, Type-III WTs are electronically coupled to the power grid. The steady-state and dynamic responses of the DFIG-based WTs depend on the behavior of the converters controllers. Accurate modeling requires reproducing the behavior of the power electronics and the control system for various operating scenarios. The analysis of this research area is carried out in two stages or tasks. The first task focuses on the balanced stator voltage situation, while the unbalanced stator …

Leaf Cutter Ant Nest Soil Cement Stabilized Earthen Bricks: Materials And Methods For Engineering Field Applications, Faith Malay

USF Tampa Graduate Theses and Dissertations

As climate change threatens vulnerable tropical climates and development outpaces resource availability, the need for diverse construction material grows. The United Nations Sustainable Development Goals aim to reduce poverty in all forms. Diversifying construction material works toward reducing indoor air pollution, the eradication of houselessness, encouraging diversification in industry, and supporting small scale industrialization. In the Province of Bocas del Toro in Panama, there is a tenuous connection to the greater industries in the country due to location and existing infrastructure.This research presents a literature review of the historical approaches to the construction and chemistry of cement stabilized earth bricks, …

Adaptive Network Slicing In Fog Ran For Iot With Heterogeneous Latency And Computing Requirements: A Deep Reinforcement Learning Approach, Almuthanna Nassar

USF Tampa Graduate Theses and Dissertations

In view of the recent advances in Internet of Things (IoT) devices and the emerging new breed of smart city applications and intelligent vehicular systems driven by artificial intelligence, fog radio access network (F-RAN) has been recently introduced for the next generation wireless communications. The capability of F-RAN has emerged to overcome the latency limitations of cloud-RAN (C-RAN) and assure the quality-of-service (QoS) requirements of the ultra-reliable-low-latency-communication (URLLC) for IoT applications. To this end, fog nodes (FNs) are equipped with computing, signal processing and storage capabilities to extend the inherent operations and services of the cloud to the edge. However, …

A Method For Compact Representation Of Heterogenous And Multivariate Time Series For Robust Classification And Visualization, Alla Abdella

USF Tampa Graduate Theses and Dissertations

Processing multivariate sensory time-series with variable lengths is a challenging problem across different application domains due to the naturally complex, high-dimensional, and often non-stationary nature of the data. There are many practical examples of this in the industry particularly for the applications of sensor networks in monitoring production or distribution of goods around the globe. This thesis tackles the specific problem of time-series data representation in how we can better summarize and visualize multi-variate time series data coming from numerous sources in a sensor network distributed across a wide range of application scenarios. On one hand, we think the analysis …

The Feasibility Of 18f-Fdg Labeled Rbc And Pet/Ct Imaging Blood Perfusion And Vascular Dysfunction Measurements In Pre-Clinical Research, Shaowei Wang

USF Tampa Graduate Theses and Dissertations

Heart disease, dementia, and stroke are significant public health issues and leading causes of mortality and morbidity worldwide. Abnormalities in blood perfusion and vascular structures are seen in varieties of pathologies, including cerebrovascular diseases like stroke and dementia, hypertension, cardiovascular disease like atherosclerosis, diabetes, peripheral artery disease, and vasculitis, and tumor angiogenesis. Imaging perfusion/vascular abnormalities in these patients often plays a vital role in clinical diagnosis and treatment decisions.

Vascular diseases typically present as macrovascular or microvascular diseases. Microvascular disease (MVD) refers to vascular disease primarily affecting the arterioles, venules, and capillaries in various organs. Furthermore, MVD is widely found …

Chorine Conversion: Biological And Water Quality Impact On Activated Carbon Block Point Of Use Filters, Horace S. Jakpa

USF Tampa Graduate Theses and Dissertations

Point-of-use (POU) activated carbon (AC) filters are ubiquitous in many U.S. households. AC can reduce concentrations of lead, other heavy metals, and mitigate taste and odor issues. However, AC filters also remove residual disinfectants, thus allowing for the proliferation of microbes in the filter. In chloraminated systems, this can lead to localized, filter-induced nitrification. Most notably, high nitrite and nitrate in drinking water can cause methemoglobinemia (blue baby syndrome) in children under the age of three, raising public health concerns.

As a control measure for nitrification within distribution systems, utilities practice periodic, short-term secondary disinfectant switches from chloramine to free …

Health Risk Assessment Of Local Populations Ingesting Water With Naturally Occurring Arsenic And Fecal Related Contaminants In Lake Atitlan, Guatemala, Marisol Alvarez

USF Tampa Graduate Theses and Dissertations

Lake Atitlan, Guatemala acts as a sink for wastewater discharge and as a source of drinking water. The populations living in the lake basin are primarily indigenous with a large percentage (70%) living in poverty. Wastewater effluent entering the lake poses an immediate health risk to those using it as a drinking-water source. Additionally, the lake is surrounded by three volcanoes and the water has concentrations of naturally occurring arsenic above the recommended reference level of 10 µg/L. Arsenic is acutely poisonous at high concentrations and has carcinogenic and neurological effects when chronically exposed at low concentrations.

The goal of …

Strategies For Achieving The United States Health System's Quadruple Aim By Enhancing The Primary Care Level, Jennifer L. Mendoza-Alonzo

USF Tampa Graduate Theses and Dissertations

The quadruple aim is an approach to optimize the performance of the health system in the United States and consists of four dimensions. The main objective is to improve the population's health, followed by reducing cost, improving patients' experience, and increasing providers' satisfaction. In the present doctoral dissertation, I explore three strategies that help accomplish the quadruple aim at the primary care level. The analysis combines data science and operation research principles to address health system engineering questions.

Each strategy proposed in this document emphasizes one objective more than another; however, all of them in conjunction serve to attain the …

Packaging Of Active Rf Beamforming Ic Utilizing Additive Manufacturing, Ryan Murphy

USF Tampa Graduate Theses and Dissertations

Packaging of an RF Beamforming IC was performed using an additive manufacturingplatform with FDM, microdispensing, laser subtractive manufacturing, and milling. The beamforming IC was embedded within a multilayer device structure in order to feed a 2x2 antenna sub-array in a compact and completely integrated package. Additive manufacturing allows for simple variation in material parameters and properties that enhances the ability to develop integrated system packaging. This study builds on previous investigations and demonstrates the ability to embed an active RF device with measurable gain within a printed plastic substrate. Critical to developing a repeatable method for this packaging solution, initial …

Sensible/Latent Hybrid Thermal Energy Storage For The Supercritical Carbon Dioxide Brayton Cycle, Kelly Osterman

USF Tampa Graduate Theses and Dissertations

Mitigating the effects of climate change will require rapid deployment of a carbon-free electricity system that includes all available forms of zero-carbon energy. Both renewables and nuclear show great promise, but both come with drawbacks. Power production from wind and solar is limited to times when their respective resources are available, while nuclear is limited in its ability to adjust its output according to the ever-varying demand for electricity. Additionally, the systems must be affordable. One way to reduce the cost of thermal power plants (concentrated solar power and nuclear) is to use new power cycles, such as the supercritical …

Dynamic Loading Directed Neural Stem Cell Differentiation, Abdullah Revaha Akdemir

USF Tampa Graduate Theses and Dissertations

Spinal cord injuries (SCI) are among the biggest challenges for medical and engineering fields in the modern era. Many people experience various accidents every year that cause major irreversible trauma in the spinal cord. Damaged neural cells caused by SCI cannot be regenerated, and patients have to live with pain, spasms, or loss of movement. Stem cell differentiation can be a potential solution to generate enough neurol cells in vitro to apply at the defective region. In this research, the impact of dynamic mechanical stimulation on the differentiation of PC-12 cell lines towards neurol cells was studied. Models to apply …

Theory And Application Of Dielectric Rod Antennas And Arrays, Gabriel Saffold

USF Tampa Graduate Theses and Dissertations

Dielectric rods have been used for many years as waveguides and radiators. Their low loss as a transmission line and tendency to radiate at discontinuities have proven useful in applications ranging from fiber optic cables to naval fire control radar. Although this technology is well es- tablished, advances in additive manufacturing techniques and associated materials combined with the ubiquity of wireless communications and their shift to higher frequencies have generated re- newed interest in dielectric rods. Dielectric rod antennas have moderate gain and less conductive loss at higher frequencies. Similar to other surface wave antennas, they can achieve broadband performance.This …