Physical Sciences and Mathematics Commons^™

Environmental And Energy Saving Technologies Of Vinyl Chloride Production, Mykola Kurta

USF Tampa Graduate Theses and Dissertations

Recently, because of the increase of environmental concerns in process design, the need to enhance conversion to product and prevent generation of wasteful byproducts in the reactor network has become urgent. This prevents high cost treatment and separation costs downstream in the process. Therefore, in this thesis I focus on making production of vinyl chloride monomer (VCM) more efficient and on possible ways of industrial organochlorine waste (OCW) recycling. In particular, in the first experiment, we investigate how catalyst and its structure can affect product output.

Infrared spectroscopy and X-ray diffraction analysis were utilized to investigate the structure of the …

Location And Capacity Modeling Of Network Interchanges, Aldo D. Fabregas

USF Tampa Graduate Theses and Dissertations

Network design decisions, especially those pertaining to urban infrastructure, are made by a central authority or network leader, and taking into consideration the network users or followers. These network decision problems are formulated as non-linear bi-level programming problems. In this work, a continuous network design problem (CNDP) and discrete network design problem (DNDP) bi-level optimization programs are proposed and solved in the context of transportation planning. The solution strategy involved reformulation and linearization as a single-level program by introducing the optimality conditions of the lower level problem into the upper level problem. For the CNDP, an alternative linearization algorithm (modified …

Topological Degree And Variational Inequality Theories For Pseudomonotone Perturbations Of Maximal Monotone Operators, Teffera Mekonnen Asfaw

USF Tampa Graduate Theses and Dissertations

Let X be a real reflexive locally uniformly convex

Banach space with locally uniformly convex dual space X^*

. Let G be a

bounded open subset of X. Let T:X⊃ D(T)⇒ 2X^*

be maximal

monotone and S: X ⇒ 2X^*

be bounded

pseudomonotone and such that 0 notin cl((T+S)(D(T)∩partG)). Chapter 1 gives general introduction and mathematical prerequisites. In

Chapter 2 we develop a homotopy invariance and uniqueness results for the degree theory constructed by Zhang and Chen for multivalued (S₊) perturbations of

maximal monotone operators. Chapter 3 is devoted to the construction of a new …

Synthesis And Investigations Of Type I And Ii Clathrates Of Group 14, Michael Blosser

USF Tampa Graduate Theses and Dissertations

Clathrates are a class of new materials that have an open-framework structure that allows guest atoms or molecules to be enclosed inside of their polyhedral framework. Varying the number, weight, and size of the guest species in a particular framework allows one to alter the physical properties of the clathrate. This relationship enables one to further the fundamental understanding of the physics and chemistry of the clathrate structure and use this knowledge to "tune" certain properties. This "tunability" of inorganic clathrates is of great interest as it allows one to optimize their physical properties; making them promising candidates for a …

Magnetism In Complex Oxides Probed By Magnetocaloric Effect And Transverse Susceptibility, Nicholas Steven Bingham

USF Tampa Graduate Theses and Dissertations

Magnetic oxides exhibit rich complexity in their fundamental physical properties determined by the intricate interplay between structural, electronic and magnetic degrees of freedom. The common themes that are often present in these systems are the phase coexistence, strong magnetostructural coupling, and possible spin frustration induced by lattice geometry. While a complete understanding of the ground state magnetic properties and cooperative phenomena in this class of compounds is key to manipulating their functionality for applications, it remains among the most challenging problems facing condensed-matter physics today. To address these outstanding issues, it is essential to employ experimental methods that allow for …

Prevention And Detection Of Intrusions In Wireless Sensor Networks, Ismail Butun

USF Tampa Graduate Theses and Dissertations

Wireless Sensor Networks (WSNs) continue to grow as one of the most exciting and challenging research areas of engineering. They are characterized by severely constrained computational and energy

resources and also restricted by the ad-hoc network operational

environment. They pose unique challenges, due to limited power

supplies, low transmission bandwidth, small memory sizes and limited energy. Therefore, security techniques used in traditional networks cannot be directly adopted. So, new ideas and approaches are needed, in order to increase the overall security of the network. Security applications in such resource constrained WSNs with minimum overhead provides significant challenges, and is the …

A Study Of Permutation Polynomials Over Finite Fields, Neranga Fernando

USF Tampa Graduate Theses and Dissertations

Let p be a prime and q = p^k. The polynomial g_n,q isin F_p[x] defined by the functional equation Sigma_{a isin Fq} (x+a)ⁿ = g_n,q(x^q- x) gives rise to many permutation polynomials over finite fields. We are interested in triples (n,e;q) for which g_n,q is a permutation polynomial of F_q^e. In Chapters 2, 3, and 4 of this dissertation, we present many new families of permutation polynomials in the form of g_n,q. The permutation behavior of g_n,q is becoming increasingly more …

Assessment Of A Modified Double Agar Layer Method To Detect Bacteriophage For Assessing The Potential Of Wastewater Reuse In Rural Bolivia, Sakira N. Hadley

USF Tampa Graduate Theses and Dissertations

Water scarcity is a global concern that impacts many developing countries, forcing people to depend on unclean water sources for domestic, agricultural, and industrial needs. Wastewater is an alternative water source that contains nutrients needed for crop growth. Wastewater reuse for agriculture can cause public health problems because of human exposure to pathogens. Pathogen monitoring is essential to evaluate the compliance of wastewater with established World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) wastewater reuse guidelines. Indicator organisms are commonly used to detect pathogens in water and wastewater because they are quick and easy to measure, non-pathogenic, and …

Spatial And Temporal Trends Of Snowfall In Central New York - A Lake Effect Dominated Region, Justin Joseph Hartnett

USF Tampa Graduate Theses and Dissertations

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as …

Refinement, Application, And Evaluation Of Cognitive And Affective Chemistry Measures For College Students, Keily Heredia

USF Tampa Graduate Theses and Dissertations

This work describes three case studies conducted to address two major problems in the area of chemistry education research, the lack of reported psychometrics regarding instrument scores, and the need for well-characterized assessments to evaluate college chemistry curricula.

The first case study describes a psychometric evaluation of the Colorado Learning Attitudes about Science Survey (CLASS), an instrument designed to assess student beliefs about the learning of chemistry. Results from this work suggest that the CLASS instrument provides fertile ground for short instruments with reasonable psychometric properties. Responses to a single scale instrument, created from CLASS, showed that students in an …

Characterizing Interactions Between Chromophores In Synthetic And Natural Macromolecular Films Via Maldi-Tof, Ibf And Dielectric Analyzer, Parul Jain

USF Tampa Graduate Theses and Dissertations

With the emergence of Matrix Assisted Laser Desorption/Ionization-Time-of-flight as a tool for diagnosis of diseases via proteomics, there is an increasing need for greater sensitivity. Analysis of peptides by MALDI-TOF-MS is affected by sample formulation and spotting onto a MALDI target. This dissertation investigates a novel MALDI sample preparation technique, Induction Based Fluidics (IBF), for depositing precise volumes (pL to nL) of samples onto the target. We have seen that while using IBF, the induced electric field accompanying deposition enhances matrix crystallization yielding smaller crystals with more homogeneity, as compared to conventional manual micropipette (MP) depositions. An investigation of the …

Spin Dependent Transport In Novel Magnetic Heterostructures, Priyanga Buddhika Jayathilaka

USF Tampa Graduate Theses and Dissertations

Magnetic oxides have become of interest source for spin transport devices due to their high spin polarization. But the real applications of these oxides remains unsatisfactory up to date, mostly due to the change of properties as a result of nano structuring. Magnetite (Fe₃O₄) is one such a material. High Curie temperature and the half metallicity of Fe₃O₄ make it a good potential candidate for spin transport devices. Studies have shown that the nano structuring Fe₃O₄ changes most of it's important properties. This includes high saturation magnetization and drop of …

Chiral Phosphoric Acid-Catalyzed Acetalization And Iso-Pictet-Spengler Reactions, Matthew Jon Kaplan

USF Tampa Graduate Theses and Dissertations

The development of novel asymmetric reaction methodologies has been invaluable in both the academic and industrial world. In just 15 years, organocatalysis has provided a new means of developing asymmetric reaction methodologies using catalysts that are environmentally benign, relatively inexpensive, bench stable, and non-toxic. One development in organocatalysis that is important to our group in particular is chiral phosphoric acid-catalysis. BINOL-derived and VAPOL-derived phosphoric acids have proven to be excellent catalysts for a number of reactions.

The two projects I will discuss my efforts on are acetalization and iso-Pictet-Spengler reactions. These were projects that I performed during my first two …

A Study On The Optimization Of Dye-Sensitized Solar Cells, Md Imran Khan

USF Tampa Graduate Theses and Dissertations

Considering biocompatibility, the Dye Sensitized Solar Cell (DSC) based on titanium dioxide should play a major role in the future of solar energy. In this ongoing study, different components and ambient process conditions for the fabrication of were investigated. Titanium dioxide substrate thickness and morphology was found to have a direct impact on the cell efficiency. Scanning Electron Microscopy (SEM) was used to investigate the TiO2 nanostructure. Different chemical treatments and electrolytes were also explored towards optimizing the cell performance. A group of porphyrin based organic dyes were synthesized and evaluated. Standard solar cell characterization techniques such as current-voltage and …

Effect Of Solids Retention Time On The Denitrification Potential Of Anaerobically Digested Swine Waste, Maureen Njoki Kinyua

USF Tampa Graduate Theses and Dissertations

Three continuously stirred tank reactors (CSTR) were operated in semi continuous mode treating swine waste using anaerobic digestion. The reactors were used to test the effect of solid retention time (SRT) on CH4 yield, total ammonia nitrogen (TAN) concentrations, % volatile solids (VS), chemical oxygen demand (COD) and volatile fatty acids (VFA) removal, readily biodegradable COD concentration and the denitrification potential for the effluent in a biological nutrient removal (BNR) system. During Phase I of the study, the three reactors were operated at the same 28 day SRT for 16 weeks. SRTs were then changed during the 12 week Phase …

Development Of Novel Nano-Composite Membranes As Introduction Systems For Mass Spectrometers: Contrasting Nano-Composite Membranes And Conventional Inlet Systems, Luis Miranda

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite …

Defining And Preventing Code-Injection Attacks, Donald Ray

USF Tampa Graduate Theses and Dissertations

This thesis shows that existing definitions of code-injection attacks (e.g., SQL-injection attacks) are flawed. The flaws make it possible for attackers to circumvent existing mechanisms, by supplying code-injecting inputs that are not recognized as such. The flaws also make it possible for benign inputs to be treated as attacks. After describing these flaws in conventional definitions of code-injection attacks, this thesis proposes a new definition, which is based on whether the symbols input to an application get used as (normal-form) values in the application's output. Because values are already fully evaluated, they cannot be considered ``code'' when injected. This simple …

Consumer Acceptance Of Mobile Payments In Restaurants, Anna Shatskikh

USF Tampa Graduate Theses and Dissertations

Regardless all the advantages of MPs, it has not reach the sizable customer base. In this paper, we examined the core drivers of using mobile payments (MPs) in restaurant industry from the consumers' perspective. Based on the Technology Acceptance Model (TAM), we developed a six factor model to reveal the determinants of consumers' intention to use MPs in restaurant. Security, subjective norm, compatibility with lifestyle, and previous experience with MPs were added to the traditional two factor TAM model (usefulness and ease of use). 300 respondents were recruited from an online survey agency and 258 valid responses were included in …

Turning Water Into Wine: The Political Economy Of The Environment In Southern California's Wine Country, Jason Simms

USF Tampa Graduate Theses and Dissertations

This dissertation examines questions of water sustainability in contexts of wine production and state-led neoliberal development in the Temecula Valley, southern California, where wine tourism is at present being harnessed as an engine of economic growth. Natural and anthropogenic forces, such as global climate change, desertification, urban development, and the marketization and commodification of natural resources, affect the distribution and availability of water throughout the globe. As a result, the use of water, and associated political and environmental processes and consequences, in the production of global commodities, including wheat, citrus, and coffee, recently have come under increased scrutiny. Given wine's …

Investigations For Utilizing Pteropods As Bioindicators Of Environmental Change Along The Western Antarctic Peninsula, Paul Mark Suprenand

USF Tampa Graduate Theses and Dissertations

Pteropods are holoplanktonic gastropod molluscs found globally. Although species diversity is greater at lower latitudes, species abundance is greater at temperate and polar latitudes. Declines in pteropod populations have not only been correlated to declines of their major predators, but pteropods have also been used as bioindicators of global environmental changes such as ocean acidification. With high latitude abundances, pteropods provide significant sustenance for species such as the Atlantic salmon in the Atlantic Ocean and Pleuragramma antarcticum in the Southern Ocean. Because pteropods eat phytoplankton and other pteropods, factors that affect pteropod abundance influence many trophic levels. This dissertation explores …

Asymmetric Nitrene Transfer Reactions With Azides Via Co(Ii)-Based Metalloradical Catalysis (Mrc), Jingran Tao

USF Tampa Graduate Theses and Dissertations

Asymmetric nitrene transfer reactions via metalloradical catalysis (MRC) with

azides has attracted research interest because of its fundamental and practical importance.

The resulting nitrogen-containing units are recurrent motifs in biologically important

molecules and can serve as versatile precursors in organic synthesis.

The [Co(D2-Por*)] have emerged as a new class of catalysts for asymmetric

aziridination and C-H amination. These metalloradical catalysts have been shown to be

highly effective for the asymmetric intermolecular aziridination of a broad scope of

substrates with different classes of azides with excellent to good enantioselectivity. The

intramolecular C-H amination utilizing various azides can allow for the construction …

Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele

USF Tampa Graduate Theses and Dissertations

The mechanisms of the sublimation of graphene at zero pressure and the condensation of carbon vapor is investigated by molecular dynamics (MD) simulations. The interatomic interactions are described by the Reactive Empirical Bond Order potential (REBO). It is found that graphene sublimates at a temperature of 5,200 K. At the onset of sublimation, defects that contain several pentagons and heptagons are formed, that are shown to evolve from double vacancies and stone wales defects. These defects consisting of pentagons and heptagons act as nucleation sites for the gaseous phase. The influence of the interatomic interactions on the sublimation process are …

Automatic Identification Of Points Of Interest In Global Navigation Satellite System Data: A Spatial Temporal Approach, Khoa Anh Tran

USF Tampa Graduate Theses and Dissertations

In addition to the emergence of smartphones and tablets in recent years, the rise of Global Navigation Satellite Systems (GNSS) has allowed mobile tracking applications to become popular and be put into many uses. Analyzing tracking records to identify points of interest (POIs) is useful for both prediction applications and research such as human behavior analysis, transportation planning, and especially travel surveys. Past research in travel surveys has shown that a GPS mobile phone-based survey is a useful tool for collecting information about individuals. Moreover, a passive travel survey collection is preferred to an active travel survey method by the …

Boolean Partition Algebras, Joseph Anthony Van Name

USF Tampa Graduate Theses and Dissertations

A Boolean partition algebra is a pair $(B,F)$ where $B$ is a Boolean

algebra and $F$ is a filter on the semilattice of partitions of $B$ where $\bigcup F=B\setminus\{0\}$. In this dissertation, we shall investigate the algebraic theory of Boolean partition algebras and their connection with uniform spaces. In particular, we shall show that the category of complete non-Archimedean uniform spaces

is equivalent to a subcategory of the category of Boolean partition algebras, and notions such as supercompleteness

of non-Archimedean uniform spaces can be formulated in terms of Boolean partition algebras.

Flexible Urban Water Distribution Systems, Seneshaw Amare Tsegaye

USF Tampa Graduate Theses and Dissertations

With increasing global change pressures such as urbanization and climate change, cities of the future will experience difficulties in efficiently managing scarcer and less reliable water resources. However, projections of future global change pressures are plagued with uncertainties. This increases the difficulty in developing urban water systems that are adaptable to future uncertainty.

A major component of an urban water system is the distribution system, which constitutes approximately 80-85% of the total cost of the water supply system (Swamee and Sharma, 2008). Traditionally, water distribution systems (WDS) are designed using deterministic assumptions of main model input variables such as water …

Computational Approaches For Structure Based Drug Design And Protein Structure-Function Prediction, Sai Lakshmana Kumar Vankayala

USF Tampa Graduate Theses and Dissertations

This dissertation thesis consists of a series of chapters that are interwoven by solving interesting biological problems, employing various computational methodologies. These techniques provide meaningful physical insights to promote the scientific fields of interest. Focus of chapter 1 concerns, the importance of computational tools like docking studies in advancing structure based drug design processes. This chapter also addresses the prime concerns like scoring functions, sampling algorithms and flexible docking studies that hamper the docking successes. Information about the different kinds of flexible dockings in terms of accuracy, time limitations and success studies are presented. Later the importance of Induced fit …

An Application Developed For Simulation Of Electrical Excitation And Conduction In A 3d Human Heart, Di Yu

USF Tampa Graduate Theses and Dissertations

This thesis first reviews the history of General Purpose computing Graphic Processing Unit (GPGPU) and then introduces the fundamental problems that are suitable for GPGPU algorithm. The architecture of GPGPU is compared against modern CPU architecture, and the fundamental difference is outlined. The programming challenges faced by GPGPU and the techniques utilized to overcome these issues are evaluated and discussed.

The second part of the thesis presents an application developed with GPGPU technology to simulate the electrical excitation and conduction in a 3D human heart model based on cellular automata model. The algorithm and implementation are discussed in detail and …

Algorithms And Data Structures For Efficient Timing Analysis Of Asynchronous Real-Time Systems, Yingying Zhang

USF Tampa Graduate Theses and Dissertations

This thesis presents a framework to verify asynchronous real-time systems based on model checking. These systems are modeled by using a common modeling formalism named Labeled Petri-nets(LPNs).

In order to verify the real-time systems algorithmically, the zone-based timing analysis method is used for LPNs. It searches the state space with timing information (represented by zones). When there is a high degree of concurrency in the model, firing concurrent enabled transitions in different order may result in different zones, and these zones may be combined without affecting the verification result. Since the zone-based method could not deal with this problem efficiently, …

Effectiveness Of Propensity Score Methods In A Multilevel Framework: A Monte Carlo Study, Aarti P. Bellara

USF Tampa Graduate Theses and Dissertations

Propensity score analysis has been used to minimize the selection bias in observational studies to identify causal relationships. A propensity score is an estimate of an individual's probability of being placed in a treatment group given a set of covariates. Propensity score analysis aims to use the estimate to create balanced groups, akin to a randomized experiment. This study used Monte Carlo methods to examine the appropriateness of using propensity score methods to achieve balance between groups on observed covariates and reproduce treatment effect estimates in multilevel studies. Specifically, this study examined the extent to which four different propensity score …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …