Digital Commons Network^™

Fabrication And Characterization Of Electrical Energy Storage And Harvesting Energy Devices Using Gel Electrolytes, Belqasem Aljafari

USF Tampa Graduate Theses and Dissertations

Redox-active materials in the bulk of gel electrolytes are unquestionably holding the primary roles in developing energy harvesting and storage technology. Both technologies are necessary in order to cope with the current challenges of the environmental crises of global warming and finite non-renewable sources while the demand for energy modern societies have been speedily increased. One of the most challenges of making a hybrid device of energy conversion and storage is the cost of the fabrication process. Therefore, gel electrolyte-based materials with redox-active properties can potentially be a promising solution to improve the performance of electrochemical and photoelectrochemical devices for …

Simulation And Experimental Investigation Of Fluid Mixing Enhancement With Orifice Plate, Mohammed Al Busaidi

USF Tampa Graduate Theses and Dissertations

Current experimental and simulation fluid mixing studies aim to increase mixing efficiency and incorporate various measurement methods to quantify mixing. In this thesis, comprehensive simulation and experimental studies were carried out to investigate the effects of an orifice plate on mixing. Mixing efficiency is measured through the correlation of volume fraction to color light reflectivity, as dyes were introduced to the fluids being mixed. Volume fractions close to 0.5 indicate high mixing performance, and the efficiency declines as volume fractions depart from 0.5. It was found that fluids in a small diameter tube do not mix due to the absence …

Measurement Of Changes In Forest Fragmentation Caused By Road Construction Between 2000 And 2014 Using Gis In St. Johns County, Florida, Ahmet Karatas

USF Tampa Graduate Theses and Dissertations

Forests play a crucial role in maintaining the natural balance. They have essential features and structures used in the protection of flora and fauna. Human activities such as road construction disrupt ecosystems and negatively impact natural habitats. Roads cause forest fragmentation, and as a result of this, fragmentation has various negative effects on the natural habitat. These effects lead to loss of biological diversity, road mortality, habitat loss, fragmentation, and air pollution. The major goal of this study was to analyze changes in forest area, forest fragmentation, and forest road impacts using GIS for St. Johns County, Florida, between the …

Sorption Of Benzene, Toluene, Ethylbenzene And Different Ratios Of Mixture Solvent By Plasticized Pema Films Using A Qcm Sensor, Xinpeng Li

USF Tampa Graduate Theses and Dissertations

VOCs (volatile organic compounds) can cause great harm to human health especially benzene, toluene and ethylbenzene. In this work a Quartz Crystal Microbalance (QCM) sensor with a polymer/plasticizer film was developed to quantify the VOCs both in air and water. QCM is an acoustic wave sensor that can be used well in detecting the aromatic compounds in the film. Because more than one VOC is present in the air, this thesis focuses on finding the sorption of different ratios of VOCs (benzene, toluene, ethylbenzene) using a polymer/plasticizer film in QCM. Poly (ethyl methacrylate) (PEMA) was used as the polymer because …

Understanding The Influence Of The Cancer Microenvironment On Metabolism And Metastasis, Shonagh Russell

USF Tampa Graduate Theses and Dissertations

Cancer is a complex and heterogeneous disease. Not only is there considerable variability between different cancer types, but there is enormous variability between and within patients who have the same type of cancer. Within tumors, there are multiple cell types, including cancer cells, stromal cells, and immune cells. The tumor microenvironment often induces the healthy cells to become pro-tumorigenic. Cell metabolism is exquisitely sensitive to changes in the tumor microenvironment and can be measured to infer the aggressiveness of cancer and predict response to therapy. In this dissertation, we aim to understand how the microenvironment, specifically low pH, affects the …

Extrusion Of Perovskite Oxide/ Silica Composites For Thermochemical Carbon Dioxide Conversion, Qian Li

USF Tampa Graduate Theses and Dissertations

In order to solve the increasing greenhouse effect problem, perovskite-type oxides have been used to convert CO2 to CO in a reverse water-gas shift chemical looping (RWGS-CL) process. Currently, the process is at the micro-reactor scale and used catalyst in powder form. However, formed materials are needed if the scale is to be increased.

Our research focus is on increasing the conversion yield of perovskite oxides with SiO2 support and scaling up the powder form perovskite-type oxides to pellet by extrusion. The binder added during the extrusion process must be removed to avoid affecting the performance of the catalyst and …

Measuring And Utilizing High-Dimensional Information Of Optical Fields, Ziyi Zhu

USF Tampa Graduate Theses and Dissertations

Currently, many areas of optical techniques including imaging, inspection and communication emphasize the utilization of the high-dimensional information encoded in optical fields. There is also a requirement for novel measurement techniques to extract this high-dimensional information with high-speed and accuracy. We firstly introduce a scan-free direct measurement technique that is capable of simultaneously characterizing the amplitude and phase of a coherent scalar optical field. Our direct measurement approach is constituted of a weak polarization perturbation which is followed by the recording of a polarization-resolving imaging process. The weak perturbation rotates the linear polarization on the spatial frequency domain of the …

Enhancing Secrecy And Capacity Of Wireless Systems Using Directive Communications, Mohammed A. Hafez

USF Tampa Graduate Theses and Dissertations

The emerging advances in wireless communications make it an essential component of our everyday life. Moreover, the current research aims towards involving wireless communications in health monitoring applications, which helps medical personnel to remotely keep track of the development of the condition of their patients. Such information is considered highly sensitive and may cause significant harm if acquired by an adversary. The wireless environment has a broadcast type of nature, where the emitted electromagnetic waves spread all over the surrounding area of the transmitting antenna. This broadcast nature raises a considerable concern about the secrecy of this sensitive information while …

Detecting Digitally Forged Faces In Online Videos, Neilesh Sambhu

USF Tampa Graduate Theses and Dissertations

We use Rossler’s FaceForensics dataset of 1004 online videos and their corresponding forged counterparts [1] to investigate the ability to distinguish digitally forged facial images from original images automatically with deep learning. The proposed convolutional neural network is much smaller than the current state-of-the-art solutions. Nevertheless, the network maintains a high level of accuracy (99.6%), all while using the entire FaceForensics dataset and not including any temporal information. We implement majority voting and show the impact on accuracy (99.67%), where only 1 video of 300 is misclassified. We examine why the model misclassified this one video. In terms of tuning …

An Archaeological Investigation Of Enslavement At Gamble Plantation, S. Matthew Litteral

USF Tampa Graduate Theses and Dissertations

In this thesis, I have compiled information from archives, remote sensing, and archaeological excavation to shed light upon an understudied chapter of Florida’s history, specifically, African American heritage components at Gamble Plantation. My goal is to provide a better understanding of the daily lives of enslaved individuals who were held in bondage at Gamble Plantation (8MA100), located along the Manatee River in Ellenton, Fl. Through my work, I hope to engage descendant communities in future archaeological research and promote a more balanced and inclusive historical narrative for Gamble Plantation State Park.

Evaluating The Evidence Base For Evidence-Based Instructional Practices In Chemistry Through Meta-Analysis, Md Tawabur Rahman

USF Tampa Graduate Theses and Dissertations

Investigating the effectiveness of instructional practices provides an evidence base to inform instructional decisions. Synthesizing research studies on instructional effectiveness provides an estimate of the generalizability of effectiveness across settings, along with an exploration of factors that may moderate the impact, which cannot be achieved within individual studies. This study sought to provide a synthesis of evidence- based instructional practices (EBIPs) particular to chemistry through meta-analysis. 99 studies were analyzed comprising a broader view of chemistry specific studies than past meta-analyses. The results showed that EBIPs feature a demonstrably positive impact on students’ academic performance in chemistry, although assessment topic …

Chemolithotrophic Denitrification Of Nitrate Contaminated Groundwater Using Sulfur-Bearing Minerals, John Sutton

USF Tampa Graduate Theses and Dissertations

Nitrate contamination in groundwater resources poses a serious threat, not only to the health of those who would drink it, but also as a potential nutrient for eutrophication. Current methods of nitrate removal can efficiently remove nitrate below 10 mg/L as nitrogen, but may require resources unavailable to small community water systems (SCWS). Sulfur-oxidizing biological denitrification is a promising alternative that may be more suitable for SCWS. Sulfur-oxidizing denitrification has previously been shown to have a high nitrate removal efficiency; however, it produces water high in sulfate. Utilization of sulfide-bearing minerals, rather than elemental sulfur as an electron donor, may …

Thermo-Oxidative Degradation Of Hdpe Geomembranes: Effect Of Phenolic Antioxidant And Hindered Amine Light Stabilizer Concentrations, Yasin Kocak

USF Tampa Graduate Theses and Dissertations

High density polyethylene (HDPE) geomembrane is most common geomembrane which is mainly used for civil engineering applications. However, HDPE geomembrane loses its properties under oxidative degradation progress. This study aims to assess geomembranes which have different percentage of phenolic antioxidant and hindered amine light stabilizer (HALS) with under the six months of the thermal-oxidative degradation. The interactions between phenolic antioxidant, HALS and carbon black can affect the mechanical, physical and chemical properties. To monitor these properties, Differential Scanning Calorimetry (DSC), Fourier-transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM/EDX), Melt Index tests, …

Interactive Fitness Domains In Competitive Coevolutionary Algorithm, Atm Golam Bari

USF Tampa Graduate Theses and Dissertations

Evolutionary Algorithms (EA) have been successfully applied to a wide range of optimization and search problems where no mathematical model of the quality of a candidate solution is available. Interactive Evolutionary Algorithms (IEA) and Competitive Coevolutionary Algorithms (CCoEA) go one step further by being able to tackle problems where the only means to evaluate the quality of a candidate solution is via interactions. In a typical IEA, interactions take place between the solution being evolved and human evaluators. In a CCoEA, interactions take place between solutions themselves, without need for human interaction. This dissertation identifies computer-aided learning as an application …

Fewer Wetlands More Connectivity: Implications Of Land Use-Land Cover Change In An Agricultural Landscape, Stephanie Lawlor

USF Tampa Graduate Theses and Dissertations

St. Lucie County (SLC) is a 1,782 km2 area in east-central Florida that drains to the Nationally Significant Indian River Lagoon (IRL). It is low lying and nearly level, with widespread non-floodplain wetlands (NFWs) and few natural channels. NFWs comprise the vast majority of SLC wetlands, both in terms of numbers and area. Since the early 20th century, SLC has undergone extensive land use-land cover (LULC) change and is now characterized by citrus farming in the interior and municipalities on its eastern coast on the Atlantic Ocean. This LULC change has been made possible by the construction of an extensive …

Morphometry And Density Analysis Of The Fifth Metacarpal, Amrita Unnikumaran

USF Tampa Graduate Theses and Dissertations

The fifth metacarpal bone fracture is a common type of fracture among the young male population. With the increasing demand for early recovery from such fractures with surgical reduction, the medical manufacturers and clinicians are interested in designing a better intramedullary device for fixation. This study is an attempt to investigate the dimensional parameters of the fifth metacarpal bone and its intramedullary canal, using 3D CT scan images of cadaveric hands. The algorithm used for measurement applies principal component analysis on the subject bone, to control the information loss and normalize the spatial position of the subject. This analysis provides …

Impact Of The Number Of Lane-Changing Times On Throughput By Fundamental Diagram Based On Ngsim Data, Gangyan Zhang

USF Tampa Graduate Theses and Dissertations

In the present report, the characteristics of the fundamental diagram (FD) are exploited to delve into the effect of the number of times of lane changes on traffic throughput. The NGSIM data are classified and screened by splitting the regions of US-101 and I-80; the relevant traffic variables (e.g., traffic flow, density and speed) are calculated. Appropriate statistical approaches are employed to verify the correlation of the impact of lane changes on different traffic variables. Lane changes could affect traffic throughput in light congestion instead of in heavy congestion. The causes of the effects of lane changes on throughput are …

Energy Transition Modeling: Social And Technical Dynamics Of Moving To Renewable Energy, Lawrence Gottschamer

USF Tampa Graduate Theses and Dissertations

The majority of global electricity is generated using fossil fuels as an energy source, and the science linking fossil fuel combustion with negative environmental impacts is clear. Recognizing this link, decarbonizing the electricity system is a critical component of climate change mitigation. However, moving electricity generation, distribution, and end-use behavior patterns to renewable energy is a complex socio-technical energy transition challenge with a number of economic, policy, technological, societal and environmental barriers. Energy transition work tends to be siloed within these topics; ignoring complex socio-technical interdependencies impacting electricity system transition dynamics. This work fills the knowledge gap with a ‘systems …

Exploring The Equity Performance Of Bike-Sharing Systems With Disaggregated Data: A Story Of Southern Tampa, Zhiwei Chen

USF Tampa Graduate Theses and Dissertations

The rising adoption of bike-sharing systems brings significant benefits to individuals and society as a whole. However, whether these benefits are distributed throughout society in a fair manner is still an open question. This study presents a methodological framework for assessing the equity performance of bike-sharing systems, with Coast Bike Share system in southern Tampa as a case study. The framework integrates three different datasets: bike-sharing infrastructure, individual travel itineraries and individual sociodemographic attribute data. With these datasets, we model individual accessibility to activity locations using bike-sharing as the mode of transportation by analyzing the “walking-cycling-walking” process of a bike-sharing …

Modeling Of Buildings With Electrochromic Windows And Thermochromic Roofs, Hua-Ting Kao

USF Tampa Graduate Theses and Dissertations

Air conditioning and heating have increased substantially during the past two decades. According to a survey, buildings consume about 73% of the total electricity in the United States, accounting for 41% of all other energy in the world. At the same time, building skin technologies are constantly improving. Electrochromic and thermochromic are two exciting new technologies that can help reduce the energy consumption of a building. The purpose of this work is to increase our understanding of how much the use of electrochromic (EC) and thermochromic (TC) technologies can reduce the energy consumption of residential and commercial buildings in two …

Sundaas Story: A Mixed-Methods Study Of Household Sanitation Provisioning In Urban Informal Housing In India, Sarita Vijay Panchang

USF Tampa Graduate Theses and Dissertations

The aims of this research were to examine sanitation insecurity in urban informal housing through the lens of the built environment, social disparities, and health implications. While the Millennium Development Goals for halving the global proportion of people without access to safe drinking water were met ahead of schedule, progress fell short for sanitation, creating new objectives for the Sustainable Development Goals to be met in 2030. Much research in the Global South is dedicated to community-level sanitation promotion, but often presumes a rural rather than urban setting. Urban informal housing settings constitute a unique challenge due to the range …

On Automation Of Code Transformations For Concept Inventory Misconceptions, Dmytro Vitel

USF Tampa Graduate Theses and Dissertations

Identifying common misconceptions held by novice programmers is a primary goalof the Computing Education Research agenda. This thesis proposes to formalize such mis-conceptions through program transformations. We first describe the implementation of theEvoParsons system, that allows students to practice programming skills with the help ofso-called Parsons puzzles. This software serves as a tool for gathering data on how studentsinteract with such puzzles. Our first contribution is the system architecture reorganization:development of Web SPA UI, REST service back-end, hypothesis validation infrastructureand student-UI data collection. We then review and compare several code-transformationtools (ANTLR, Rascal MPL and StrategoXT) and show how they might …

A Communication-Centric Framework For Post-Silicon System-On-Chip Integration Debug, Yuting Cao

USF Tampa Graduate Theses and Dissertations

System-on-Chip (SoC) plays an important role in people’s everyday life. These systems are often deployed in critical applications, bugs discovered after their deployment in field can be extremely expensive, resulting in catastrophic loss of company revenues, compromise of personal and national security, and even human life. Post-silicon debug is a critical component of the validation of modern microprocessors and SoC designs. A major challenge in post-silicon debug is the severely limited observability where only a small number of debug interface signals are available to observe a vast space of internal executions of SoC designs. This dissertation addresses the above issues …

Students' Perceptions On Alternative Break Experiences And Selecting An Academic Major In A Four-Year College, Bianny Fernández Collado

USF Tampa Graduate Theses and Dissertations

Research shows that 50-80% of college students are exploratory/undecided or appear as declared and will change their major at least once. Although higher education institutions have developed and implemented several initiatives to assist students with selecting an academic major, students are struggling to reach this milestone. According to Gebhard (2015), real-world and experiential opportunities successfully prepare students to select an academic major. Thus, the purpose of this qualitative exploratory study is to describe in-depth a phenomenon: how a service-based experience, offered through an Alternative Breaks (aB) program may prepare student participants for the selection of an academic major. The study …

Authentication Usability Methodology, Jean-Baptiste Subils

USF Tampa Graduate Theses and Dissertations

Nowadays many systems require end users to authenticate themselves. Authentication is one of the security activities that end users perform the most. Thus, the usability of this security feature plays a major role in the proper utilization and adoption of a novel authentication method.

This dissertation presents coauthentication, a novel authentication system. Many authentication methods and protocols exist, but passwords remain the predominant authentication method used. Coauthentication is presented here in detail in several possible variations and their associated protocols, with performance comparisons.

This dissertation also presents a framework to evaluate authentication methods in terms of usability.

A large body …

A Gpu-Based Framework For Parallel Spatial Indexing And Query Processing, Zhila Nouri Lewis

USF Tampa Graduate Theses and Dissertations

Support for efficient spatial data storage and retrieval have become a vital component in almost all spatial database systems. Previous work has shown the importance of using spatial indexing and parallel computing to speed up such tasks. While GPUs have become a mainstream platform for high-throughput data processing in recent years, exploiting the massively parallel processing power of GPUs is non-trivial. Current approaches that parallelize one query at a time have low work efficiency and cannot make good use of GPU resources. On the other hand, many spatial database applications are busy systems in which a large number of queries …

Restoring International Justice: Exposing The Limitations Of Retributive Justice And Proposing A Restorative Dimension, Nazek Jawad

USF Tampa Graduate Theses and Dissertations

This dissertation exposes the limitation of international retributive justice in realizing interstate reconciliation and proposes including a restorative dimension into the existing international criminal justice system. I maintain that justice within the international criminal system is conceptualized purely on a punitive notion influenced by the liberal institutionalist understanding of the state and the international system. Hence, the current retributive structure does not engage rival stakeholders, who experience interstate wars, in the process of international justice, as it is centered on upholding international law and punishing states that violate the law. To this end, the current process is not equipped to …

Multimodal Emotion Recognition Using 3d Facial Landmarks, Action Units, And Physiological Data, Diego Fabiano

USF Tampa Graduate Theses and Dissertations

To fully understand the complexities of human emotion, the integration of multiple physical features from different modalities can be advantageous. Considering this, this thesis presents an approach to emotion recognition using handcrafted features that consist of 3D facial data, action units, and physiological data. Each modality independently, as well as the combination of each for recognizing human emotion were analyzed.

This analysis includes the use of principal component analysis to determine which dimensions of the feature vector are most important for emotion recognition. The proposed features are shown to be able to be used to accurately recognize emotion and that …

Device For Imaging Cross-Section Of Post-Tensioned Structural Tendons In The Field, David Dukeman

USF Tampa Graduate Theses and Dissertations

With increasing use of grouted post-tensioned tendons in structures, there is a critical need for equipment to determine deficient grouting. Inadequate grouting can cause dangerous corrosion of the high-strength post-tensioning steel in the tendons. Evaluation should be non-destructive, and early detection is needed to take timely remedial actions to repair or replace any tendons that are affected before catastrophic failure occurs. In particular, there is need for an imaging method that shows the cross-section of the tendon being tested and flag any deficiencies present relative to the location of the strands in the cross section. The method should be rapid, …

The Relationship Between Continuous Glucose Monitor (Cgm) Derived Metrics And Indices Of Glycemic Control, Ryan Bailey

USF Tampa Graduate Theses and Dissertations

Introduction: Both hypoglycemia (low blood glucose) and hyperglycemia (high blood glucose) are common among individuals with type 1 diabetes and are associated with severe medical complications, therefore it is essential that health care providers are able to accurately measure glycemic control. Measures derived from continuous glucose monitoring (CGM) may provide more accurate measurements of glycemia than the commonly used HbA1c blood test.

Methods: Data from the Juvenile Diabetes Research Foundation (JDRF) clinical trial to assess the efficacy of continuous glucose monitoring was used to estimate the ability of CGM composite scores to predict time in range, time in hyperglycemia and …