Digital Commons Network^™

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

Secure Communication Scheme In Smart Home Environment, Hari Krishna Jonnalagadda

USF Tampa Graduate Theses and Dissertations

Internet of Things, has started to mark its existence from past few years. Right from its inception with a coke machine at Carnegie Mellon University, it has come a long way, connecting billions of devices to internet. This journey is well supported by the advancements in networking, hardware miniaturization and sensing capabilities. Diverse nature of applications of Internet of Things, has cut the communication barriers between the varieties of fields ranging from manufacturing industry to health-care industry. Smart Home is one such application of Internet of Things. Connectivity of home appliances, to achieve automation in living, defines Smart Home. Out …

Environmental And Community Health In South San Diego County: A Behavior Analysis Of Recreational Ocean Users Along Imperial Beach, California, Trista Brophy

USF Tampa Graduate Theses and Dissertations

Garbage & sewage runoff into the Pacific Ocean at the shoreline along the U.S./Mexico Border region poses serious health and environmental threats. The purpose of this study was to analyze the current beach users’ behavioral factors that may be linked to illness prevalence from Coronado Island to the U.S./Mexico border at Imperial Beach in San Diego County. It is a continuation of a study completed by Wildcoast and Imperial Beach Clinic in 2011. The study tried to answer the following two major questions: How have the number of illnesses reported by users along South San Diego County beaches changed in …

Preparation And Characterization Of Van Der Waals Heterostructures, Horacio Coy Diaz

USF Tampa Graduate Theses and Dissertations

In this dissertation different van der Waals heterostructures such as graphene-MoS₂ and MoTe₂-MoS₂ were prepared and characterized. In the first heterostructure, polycrystalline graphene was synthesized by chemical vapor deposition and transferred on top of MoS₂ single crystal. In the second heterostructure, MoTe₂ monolayers were deposited on MoS₂ by molecular beam epitaxy.

Characterization of graphene-MoS₂ heterostructures was conducted by spin and angle resolve spectroscopy which showed that the electronic structure of the bulk MoS₂ and graphene in this van der Waals heterostructures is modified. For MoS₂ underneath the graphene, a band …

Impact Of Sludge Layer Geometry On The Hydraulic Performance Of A Waste Stabilization Pond, Faissal Romaric Ouedraogo

USF Tampa Graduate Theses and Dissertations

Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is needed. One major factor determining the hydraulic performance of a WSP is sludge accumulation, which alters the volume of the pond.

In this study, computational fluid dynamics (CFD) analysis was applied to investigate the impact of sludge layer geometry on …

Microcavity Enhanced Raman Scattering, Benjamin James Petrak

USF Tampa Graduate Theses and Dissertations

Raman scattering can accurately identify molecules by their intrinsic vibrational frequencies, but its notoriously weak scattering efficiency for gases presents a major obstacle to its practical application in gas sensing and analysis. This work explores the use of high finesse (50 000) Fabry-Pérot microcavities as a means to enhance Raman scattering from gases. A recently demonstrated laser ablation method, which carves out a micromirror template on fused silica--either on a fiber tip or bulk substrates-- was implemented, characterized, and optimized to fabricate concave micromirror templates ~10 µm diameter and radius of curvature. The fabricated templates were coated with a high-reflectivity …

On Spectral Properties Of Single Layer Potentials, Seyed Zoalroshd

USF Tampa Graduate Theses and Dissertations

We show that the singular numbers of single layer potentials on smooth curves asymptotically behave like O(1/n). For the curves with singularities, as long as they contain a smooth sub-arc, the resulting single layer potentials are never trace-class. We provide upper bounds for the operator and the Hilbert-Schmidt norms of single layer potentials on smooth and chord-arc curves. Regarding the injectivity of single layer potentials on planar curves, we prove that among single layer potentials on dilations of a given curve, only one yields a non-injective single layer potential. A criterion for injectivity of single layer potentials on …

Tunable Nano-Delivery System For Cancer Treatment: A New Approach For Targeted Localized Drug Delivery, Rana Falahat

USF Tampa Graduate Theses and Dissertations

Localized drug delivery systems have been widely studied as potential replacements for conventional chemotherapy with the capability of providing sustained and controlled drug release in specific targeted sites. They offer numerous benefits over conventional chemotherapy such as enhancing the stability of embedded drugs and preserving their anticancer activity, providing sustained and controlled drug release in the tumor site, reducing toxicity and diminishing subsequent side effects, minimizing the drug loss, averting the need for frequent administrations, and minimizing the cost of therapy.

The aim of this study is to develop a localized drug delivery system with niosomes embedded in a chitosan …

Video Data Collection For Continuous Identity Assurance, Janani Venkatesan

USF Tampa Graduate Theses and Dissertations

Frequently monitoring the identity of a person connected to a secure system is an important component in a cyber-security system. Identity Assurance (IA) mechanisms which continuously confirm and verify users’ identity after the initial authentication process ensure integrity and security. Such systems prevent unauthorized access and eliminate the need of an authorized user to present credentials repeatedly for verification. Very few cyber-security systems deploy such IA modules. These IA modules are typically based on computer vision and machine learning algorithms. These algorithms work effectively when trained with representative datasets. This thesis describes our effort at collecting a small dataset of …

The Development Of A Prosthetic Training Software For Upper Limb Amputees, Tyler Kayne Sullins

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to develop an intuitive software that aids in the field of prosthetic training and rehabilitation by creating an individualized visualization of joint angles. This software is titled “the prosthetic training software (PTS) for individualized joint angle representation”, and it enables the individualized portrayal of predicted or pre-recorded joint angles. The PTS is an intuitive program for clinicians and prosthesis users that produces an animation of a virtual avatar reflecting the user’s segment lengths and amputation for rehabilitation and training purposes.

The PTS consists of a graphical user interface (GUI) and a 3D visualization of …

Some Results Concerning Permutation Polynomials Over Finite Fields, Stephen Lappano

USF Tampa Graduate Theses and Dissertations

Let p be a prime, p a power of p and 𝔽_q the finite field with q elements. Any function φ: 𝔽_q → 𝔽_q can be unqiuely represented by a polynomial, 𝔽_φ of degree < q. If the map x ↦ F_φ(x) induces a permutation on the underlying field we say F_φ is a permutation polynomial. Permutation polynomials have applications in many diverse fields of mathematics. In this dissertation we are generally concerned with the following question: Given a polynomial f, when does the map x ↦ F( …

Blind And Visually Impaired Users Adaptation To Web Environments: A Qualitative Study, Raneem Saqr

USF Tampa Graduate Theses and Dissertations

Although much research exists on human behavior in online environments, research on users with disabilities is still rare. To draw more attention to this population, this dissertation explored browsing patterns and adaptive behaviors of people with visual disability across different online environments common in daily activities: social network, e-commerce, online information, and search engines’ websites. The main objective of this study is to propose a conceptual framework of how blind and visually impaired users browse and adapt to different web environments. We achieve this objective using a qualitative approach through three studies. In the first study, the researchers collect data …

Spatially Directional Resorcin[4]Arene Cavitand Glycoconjugates For Organic Catalysis In Aqueous Media, Ali Husain Husain

USF Tampa Graduate Theses and Dissertations

Resorcin[4]arenes and their rigid structures “cavitands” offer a unique molecular structure scaffolds suitable for attaching and orienting multi-ligands on their upper rims. Their remarkable structure properties, the relative ease of chemical modification on their either rims or through the multiple phenolic hydroxyl (-OH) groups, manipulating their cavity size and the role of spatial directionality provided by their cores, led synthetic chemist to explore their utilities in the synthesis of valuable resorcin[4]arene/cavitand assemblies with wide range of applications in many research areas such as supramolecular chemistry, host-guest chemistry, glycoconjugates, polymer chemistry, host-guest chemistry, micro-reactors in chemical catalysis and others. In particular, …

Msspark: Implementation Of Molecular Simulation Queries Using Apache Spark, Parneet Kaur

USF Tampa Graduate Theses and Dissertations

Huge amount of data is being generated in almost every field and it cannot be avoided, rather is essential for the advancement of the field. Analysis of this data requires intensive computing power. Molecular Simulation is a powerful tool for understanding the behavior of natural systems. The simulation generates large amount data while observing the spatial and temporal relationships. The challenge is to handle the analytical queries that are often compute intensive.

Although various tools exist to tackle this problem, but in this paper we have tried an alternate approach that uses Apache Spark- a modern big data platform – …

Statistical Analysis Of A Risk Factor In Finance And Environmental Models For Belize, Sherlene Enriquez-Savery

USF Tampa Graduate Theses and Dissertations

The objectives of the study are to review and evaluate four basic risk models that are commonly used in investment science; statistically investigate the risk factor in Capital Asset Pricing Model (CAPM) that is used to reflect the safety of an investment decision in stocks; explore the statistical distribution of monthly precipitation in Belize and to forecast tourist arrivals using statistical time series modelling techniques.

The risk models are the Capital Asset Pricing Model (Sharpe-Linter Version), Capital Asset Pricing Model (Conditional Version), Arbitrage Pricing Theory, and Fama–French three-factor model adopted in empirical investigations of asset pricing. The underlying assumptions of …

Do Early Elementary Teacher Ratings Of Classroom Behavior Predict Similar Outcomes Across Demographic Groups? An Examination Using The Early Childhood Longitudinal Study Kindergarten Cohort (Ecls-K), Amira Conservilla Mattison

USF Tampa Graduate Theses and Dissertations

Research suggests that how teachers perceive the behavior of individual children in the early years of elementary school has important implications for the school success of those youth over time (Darney et al., 2013; Hibel et al., 2010; Jimerson et al., 1997; Reinke et al., 2008). This may be because children who are of concern to teachers are often identified for practices such as grade retention and/or special education placement. Although these practices are intended to help children, they have not been shown to be associated with long-term positive outcomes. Rather, youth who are subject to these practices experience negative …

Inquiry Of Lipid Membranes Interacting With Functional Peptides And Polyphenol Drug Molecules, Chian Sing Ho

USF Tampa Graduate Theses and Dissertations

Cellular membranes are important targets for many membrane-active peptides and drug compounds. Here we are interested in deciphering how lipid membranes are perturbed by several membrane-active molecules, including the transmembrane domain of the influenza M2 protein (M2TM), aggregates formed by a synthetic polyglutamine peptide, and three polyphenol compounds (i.e., tamoxifen, genistein, and verapamil). We employ phase-separated ternary lipid model membranes in the form of giant unilamellar vesicles (GUVs) to simulate raft-like structures that have been proposed to govern many important processes in plasma membranes (e.g., intracellular singling and trafficking). Specifically, we use fluorescent microscopy to interrogate how those membrane additives …

An Analysis Of The Formal And Informal Professional Learning Practices Of Middle And High School Mathematics Teachers, Kelly Elizabeth Mccarthy

USF Tampa Graduate Theses and Dissertations

Although there has been a substantial amount of research on the topic of teacher professional development, few studies adequately captured the types and frequency of formal and informal professional learning teachers undertake to improve as educators. The purpose of this study was to examine the types of activities middle and high school mathematics teachers engaged in to improve their abilities as educators, analyzed by the participants’ school setting, years of teaching experience, level of education, degree major, certificate type, and their school’s Title I status.

Teachers from two large school districts in Florida participated. The Teachers’ Opportunity to Learn (TOTL) …

Use Of A Game-Based App As A Learning Tool For Students With Mathematics Learning Disabilities To Increase Fraction Knowledge/Skill, Orhan Simsek

USF Tampa Graduate Theses and Dissertations

The aim of this study was to investigate the effectiveness of a game-based app (Motion Math: Fraction) to help students with Mathematics Learning Disabilities (MLD) to gain fraction skills including comparison, estimation, and word problem solving in an after school program. The researcher used multiple baseline design by extending with follow-up phase to determine whether students retained the knowledge they learned while engaging with the app. Even though six students participated to the study, the researcher withdrew two of them and analyzed data came from four students. The result o the study showed that all of the students …

Preservice Teachers Engaged In Professional Learning Community To Explore Critical Literacy, Vanessa Casciola

USF Tampa Graduate Theses and Dissertations

As demographics change, our school populations are ever changing. Preservice teachers (PSTs) need to be aware of how to meet the needs of all of their future students. Teacher education programs have been charged with the duty of preparing these PSTs for the diverse school population they will encounter. This qualitative multiple case study focused on the influence of specific work with PSTs in the inquiry process within a learning community to make sense of critical literacy. The following research questions guided this study: (1) How do elementary PSTs engaged in practitioner inquiry make meaning of critical literacy instruction within …

Optimizing Methods For Extraction Of Organic Compounds From Molluscan Shells, Kaydee Jo West

USF Tampa Graduate Theses and Dissertations

Mollusk shells contain proteins within and between the crystals of calcium carbonate. These organic molecules play an important role in biomineralization and shell function, and their stable isotope ratios of carbon and nitrogen are also thought to record important ecological information about the animal's diet and nutrient sources. These proteins can be preserved for millions of years, offering potential insight into pre-anthropogenic ecological conditions. However, shell organics in older shells are typically recovered in reduced abundances due to leaching and remaining organics are often converted from insoluble proteins to soluble, free amino acids, making them difficult to detect and recover. …

Sustainability At U.S. Urban Water Utilities: A Framework To Assess Key Attributes, Matthew Paul Ries

USF Tampa Graduate Theses and Dissertations

Urban water utilities in the United States face challenges due to a combination of external drivers. These include urbanization and population growth, which are stressing a system of aging infrastructure. Compliance with increasing regulations is also a challenge in a fiscally-constrained economic environment. A changing climate threatens infrastructure and past assumptions for water supply and quality. Urban utilities provide clean water and sanitation services to over 80% of the country’s population and its industrial centers. Therefore, the sustainability of these water utilities are crucial to the country’s and the public’s well-being.

New operating models are emerging for a “utility of …

The Effects Of Age And Gender On Pedestrian Traffic Injuries: A Random Parameters And Latent Class Analysis, Tatok Raharjo Raharjo

USF Tampa Graduate Theses and Dissertations

Pedestrians are vulnerable road users because they do not have any protection while they walk. They are unlike cyclists and motorcyclists who often have at least helmet protection and sometimes additional body protection (in the case of motorcyclists with body-armored jackets and pants). In the US, pedestrian fatalities are increasing and becoming an ever larger proportion of overall roadway fatalities (NHTSA, 2016), thus underscoring the need to study factors that influence pedestrian-injury severity and potentially develop appropriate countermeasures. One of the critical elements in the study of pedestrian-injury severities is to understand how injuries vary across age and gender ‒ …

Longitudinal Study Of Adjustable Workstations, Megan Elizabeth Sandy

USF Tampa Graduate Theses and Dissertations

Workplace interventions to reduce discomfort and sedentary time have been studied in a variety of settings. Adjustable workstations are one type of ergonomic intervention that is used to potentially reduce occupational sitting time, negative health impacts, and to increase productivity. This investigation compared two types of ergonomic interventions, as well as contrasting behavioral interventions among workers with and without adjustable workstations. Seventy-two sedentary office workers were selected to participate in a longitudinal study to evaluate interventions for a reduction in occupational sitting time, to understand the effect on productivity and to evaluate musculoskeletal pain and behaviors. Workers were randomly placed …

Hamiltonian Formulations And Symmetry Constraints Of Soliton Hierarchies Of (1+1)-Dimensional Nonlinear Evolution Equations, Solomon Manukure

USF Tampa Graduate Theses and Dissertations

We derive two hierarchies of 1+1 dimensional soliton-type integrable systems from two spectral problems associated with the Lie algebra of the special orthogonal Lie group SO(3,R). By using the trace identity, we formulate Hamiltonian structures for the resulting equations. Further, we show that each of these equations can be written in Hamiltonian form in two distinct ways, leading to the integrability of the equations in the sense of Liouville. We also present finite-dimensional Hamiltonian systems by means of symmetry constraints and discuss their integrability based on the existence of sufficiently many integrals of motion.

Urban English Language Arts Teachers’ Stories Of Technology Use: A Narrative Inquiry, Bridget Abbas

USF Tampa Graduate Theses and Dissertations

Technology use in high-minority, low-income middle school ELA classrooms is defined by traditional instructional practices (Applebee & Langer, 2013; Attewell, 2001; Boser, 2013; Cuban, 2001; Lankshear & Knobel, 2008), barriers to access (O’Dwyer et al., 2005; Purcell et al., 2013; Warschauer & Matuchniak, 2010), and inequalities in use (Banister & Reinhart, 2011; Beers, 2004; Gorski, 2009; Makinen, 2006; Powell, 2007; Reinhart et al., 2011; Dijk, 2003, 2006; Warschauer et al., 2004). This characterization, or grand narrative, of technology use is echoed and challenged by this narrative inquiry. Here the stories of two ELA teachers frequently using technology in instruction and …

Development And Validation Of A Remote Sensing Model To Identify Anthropogenic Boreholes That Provide Dry Season, Refuge Habitat For Anopheles Vector Mosquitoes In Sub-Saharan Africa, James Pkemoi Kukat

USF Tampa Graduate Theses and Dissertations

A lack of surveillance systems is an impediment to public health intervention for perennial vector-borne disease transmission in northern tropical savanna region of Kenya. The population in this area are mostly poor nomadic pastoralists with little acquired functional immunity to Plasmodium falciparum, due to infrequent challenges with the parasite. A common characteristic in tropical savanna climatic zone is the availability of riverbeds that have anthropogenic boreholes that provide malaria vector mosquitoes, such as Anopheles gambiae s.l and Anopheles funestus, with aquatic refuge habitats for proliferation and endemic transmission to proximity human households during the dry-season. Unfortunately, currently there …

Putnam's Inequality And Analytic Content In The Bergman Space, Matthew Fleeman

USF Tampa Graduate Theses and Dissertations

In this dissertation we are interested in studying two extremal problems in the Bergman space. The topics are divided into three chapters.

In Chapter 2, we study Putnam’s inequality in the Bergman space setting. In [32], the authors showed that Putnam’s inequality for the norm of self-commutators can be improved by a factor of 1 for Toeplitz operators with analytic symbol φ acting on the Bergman space A2(Ω). This improved upper bound is sharp when φ(Ω) is a disk. We show that disks are the only domains for which the upper bound is attained.

In Chapter 3, we consider the …

Global Attractors And Random Attractors Of Reaction-Diffusion Systems, Junyi Tu

USF Tampa Graduate Theses and Dissertations

The dissertation studies about the existence of three different types of attractors of three multi-component reaction-diffusion systems. These reaction-diffusion systems play important role in both chemical kinetics and biological pattern formation in the fast-growing area of mathematical biology.

In Chapter 2, we prove the existence of a global attractor and an exponential attractor for the solution semiflow of a reaction-diffusion system called Boissonade equations in the L² phase space. We show that the global attractor is an (H, E) global attractor with the L^∞ and H² regularity and that the Hausdorff dimension and the …

A Communication Protocol For Nanogrids And Its Application In Off-Grid Rural Areas Of Developing Countries, Sowmya Srikanth

USF Tampa Graduate Theses and Dissertations

In a developing country such as India, 44% of the population does not have access to power and for many others, the power supply is unreliable. A nanogrid, defined as “a single domain for voltage, reliability and administration”, is a possible solution to distribute power to such off-grid areas. Built from the bottom up, nanogrids have the ability to function independently, using locally generated power (such as solar power) as the power source. Such grids enable residents to lead more productive lives, with improved access to power. This thesis designs a new communication protocol for nanogrids to enable matching demand …