Physical Sciences and Mathematics Commons^™

Surface Science Studies Of Graphene Interfaces, Arjun Dahal

USF Tampa Graduate Theses and Dissertations

Interfaces between graphene and dissimilar materials are needed for making devices, but those interfaces also modify the graphene properties due to charge transfer and/or symmetry breaking. In this dissertation we investigate the technology of preparing graphene on different substrates and how the substrate influences the electronic properties of graphene.

Synthesizing large area graphene on late transition metals by chemical vapor deposition is a promising approach for many applications of graphene. Among the transition metals, nickel has advantages because the good lattice match and strong interaction between graphene/Ni(111) enables the synthesis of a single domain of graphene on Ni(111). However, the …

Biosynthesis Of Long-Chain Fatty Acid Amides, Kristen A. Jeffries

USF Tampa Graduate Theses and Dissertations

The vast variety of long-chain fatty acid amides identified in biological systems is intriguing. The general structure of a fatty acid amide is R-CO-NH-X, where R is an alkyl group and X is derived from an immense variety of biogenic amines. Although structurally simple, the bioactivities of these molecules as signaling lipids are very diverse and have just recently begun to emerge in the literature. Interest in the long-chain fatty acid amides dramatically increased following the identification and characterization of one specific N-acylethanolamine, N-arachidonoylethanolamine (anandamide), as the endogenous ligand for the cannabinoid receptors in the mammalian brain. Since …

Metal Organic Frameworks (Mofs) And Porous Organic Polymers (Pops) For Heterogeneous Asymmetric Catalysis, Youngran Ji

USF Tampa Graduate Theses and Dissertations

The administration of enantiopure drugs brings advantages such as improved efficacy, more predictable pharmacokinetics and reduced toxicity from the point of view of the pharmaceutical area.[1] For this reason, a tremendous amount of supply and demand for enantiomeric pure compounds has been shown not only in market, but industry and academia.[^2-4] According to the industry publication Genetic Engineering and Biotechnology News (GEN) in 2014, 22 billion dollars were accounted for enantiopure form of drugs such as Sovaldi® (Sofosbuvir), Crestor® (Rosuvastatin), and Advair® (fluticasone/salmeterol).

The fact that one enantiomer can be pharmacologically effective whereas the other enantiomer can be …

Communication Of Lava Flow Hazards At The San Francisco Volcanic Field, Flagstaff, Arizona, Catherine St. John Carter

USF Tampa Graduate Theses and Dissertations

This thesis examines different methods of communicating volcanic hazards to the population of Flagstaff, Arizona using the results of a recent lava flow hazard assessment of the nearby San Francisco Volcanic Field (SFVF). Harburger (2014) determined that given a lava flow originating in the SFVF, there is a statistical probability that it will inundate the city of Flagstaff or even originate from a vent within the city limits. Based on the recurrence rates for the most recent eruptions (3 x 10-4/year), the probability of lava flow inundation in Flagstaff is 1.1 x 10-5 per year.

This study considers the effects …

Tornado Fatalities: An In-Depth Look At Physical And Societal Influences, Heather Joann Key

USF Tampa Graduate Theses and Dissertations

The purpose of this study is to model and determine significant predictors of tornado death index values, and to investigate these significant predictors and what makes people vulnerable to tornado fatalities through expert interviews. This study also provides an understanding of the study participant’s perceptions of their county’s vulnerability to tornado fatality and demonstrates a true integration of methods and fields by studying geographic, meteorological, and sociological phenomena by use of quantitative and qualitative methods. The study consists of two parts: 1) A quantitative exploration of variables hypothesized to predict Tornado Death Index (TDI) values, 2) A qualitative investigation to …

Schreibersite: Synthesis, Characterization And Corrosion And Possible Implications For Origin Of Life, Nikita Latesha La Cruz

USF Tampa Graduate Theses and Dissertations

We present study of the synthesis and reactions of an analog of the meteoritic mineral schreibersite with formula (Fe,Ni)3P, believed to be a prebiotic source of reactive phosphorus that may have prompted the formation of phosphorylated biomolecules near the time of the origin of life (Pasek and Lauretta, 2005). The mineral was synthesized by mixing stoichiometric proportions of elemental iron, nickel and phosphorus and heating in a tube furnace at 820°C for approximately 235 hours under argon or under vacuum, a modification of the method of Skála and Drábek (2002). The mineral was characterized using X-ray diffractometry (XRD), X-ray photoelectron …

Patient Populations, Clinical Associations, And System Efficiency In Healthcare Delivery System, Yazhuo Liu

USF Tampa Graduate Theses and Dissertations

The efforts to improve health care delivery usually involve studies and analysis of patient populations and healthcare systems. In this dissertation, I present the research conducted in the following areas: identifying patient groups, improving treatments for specific conditions by using statistical as well as data mining techniques, and developing new operation research models to increase system efficiency from the health institutes’ perspective. The results provide better understanding of high risk patient groups, more accuracy in detecting disease’ correlations and practical scheduling tools that consider uncertain operation durations and real-life constraints.

Experimental Investigation Of Encapsulated Phase Change Materials For Thermal Energy Storage, Tanvir E. Alam

USF Tampa Graduate Theses and Dissertations

Thermal energy storage (TES) is one of the most attractive and cost effective solutions to the intermittent generation systems like solar, wind and other renewable sources, compared to alternatives. It creates a bridge between the power supply and demand during peak hours or at times of emergency to ensure the continuous supply of energy. Among all the TES systems, latent heat thermal energy storage (LHTES) draws lots of interests as it has high energy density and can store or retrieve energy isothermally. Two major technical challenges associated with the LHTES are low thermal conductivity of the phase change materials (PCMs), …

Sound Attenuation Performance Of Fiber-Reinforced Polymer Composite Circumaural Hearing Protection Devices, Steven Christopher Augustine

USF Tampa Graduate Theses and Dissertations

Personnel who work on the flight deck of an aircraft carrier are exposed to extreme levels of jet engine noise often in excess of 140 decibels (dB). The current circumaural hearing protective devices (CAHPD) employed by flight deck crewmen are inadequate for the level of protection required for these extreme levels of noise. Fiber-reinforced thermoset polymer composite (FRPC) materials such as aramid fibers used in body armor, have high theoretical values of acoustic impedance due to a fundamentally high modulus of elasticity and may offer a superior level of hearing protection over original equipment (OE) thermoplastic CAHPDs. The objective of …

The Use Of Textural Kinetic Habitats To Mine Diagnostic Information From Dce Mr Images Of Breast Tumors, Baishali Chaudhury

USF Tampa Graduate Theses and Dissertations

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of the breast is a widely used non-invasive approach to gather information about the underlying physiology of breast tumors. Recent studies indicate that breast tumor heterogeneity may reflect the presence of different levels of cellular aggressiveness or habitats within the tumor. This heterogeneity has been correlated to the variations in the contrast enhancement patterns within the tumor apparent on gadolinium-enhanced DCE-MRI. Although pathological and qualitative (based on contrast enhancement patterns) studies suggest the presence of clini- cal and molecular predictive tumor sub-regions, this has not been fully investigated in the quantitative domain.

The …

Achieving Reliable Generation \& Delivery Of Energy Through Robust Optimization, Anna Danandeh

USF Tampa Graduate Theses and Dissertations

In this dissertation, we elaborate on the inherent risks and uncertainties in power systems and associated industries, and develop practical solution methods to eliminate their adverse effects.

our research agenda consists of practice-driven problems in different stages of power generation as follows. (1) Affordable fuel procurement through developing a comprehensive fuel supply chain design and operations planning system for electricity generation companies, (2) reliable electricity generation through incorporating dynamic asset rating concept in the unit commitment problem, and (3) efficient demand management through proposing a job scheduling model for effective local generation consumption.

Since reliability cannot be compromised in energy …

Analysis Of Carbon Policies For Electricity Networks With High Penetration Of Green Generation, Felipe Feijoo

USF Tampa Graduate Theses and Dissertations

In recent decades, climate change has become one of the most crucial challenges for humanity. Climate change has a direct correlation with global warming, caused mainly by the green house gas emissions (GHG). The Environmental Protection Agency in the U.S. (EPA) attributes carbon dioxide to account for approximately 82\% of the GHG emissions. Unfortunately, the energy sector is the main producer of carbon dioxide, with China and the U.S. as the highest emitters. Therefore, there is a strong (positive) correlation between energy production, global warming, and climate change. Stringent carbon emissions reduction targets have been established in order to reduce …

Effects Of Solids Retention Time And Feeding Frequency On Performance And Pathogen Fate In Semi-Continuous Mesophilic Anaerobic Digesters, Nathan Daniel Manser

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is a biochemical process in which organic carbon is biodegraded in an oxygen free environment through a microbial consortium. Engineered biological systems used for resource recovery often utilize anaerobic digestion to treat anthropogenic organic wastes by reclaiming the carbon as energy (methane gas) and a soil amendment (biosolids). Small-scale, or household, semi-continuous anaerobic digesters have been used in developed and developing countries for many decades to produce biogas from human and livestock waste, which is used for heating, lighting, and cooking. This application has been shown to improve the quality of life of the user. Although there is …

Assessment Of Public Health Risks Associated With Petrochemical Emissions Surrounding An Oil Refinery, Erin L. Pulster

USF Tampa Graduate Theses and Dissertations

Refinery operations have been associated with a wide variety of atmospheric emissions consisting of criteria air pollutants, volatile organic components, hazardous air pollutants as well as other pollutants. With approximately 100 oil refineries in the Wider Caribbean region (WCR), hydrocarbons in this region pose significant environmental and human health risks. One of the oldest and largest refineries in the WCR is the Isla Refineriá, which is located on the island of Curaçao, and has been the basis of historical debates and conflict between the public and the local government over the environmental and human health risks. This research aims to …

Theoretical Investigations Of Gas Sorption And Separation In Metal-Organic Materials, Tony Pham

USF Tampa Graduate Theses and Dissertations

Metal--organic frameworks (MOFs) are porous crystalline materials that are synthesized from rigid organic ligands and metal-containing clusters. They are highly tunable as a number of different structures can be made by simply changing the organic ligand and/or metal ion. MOFs are a promising class of materials for many energy-related applications, including H₂ storage and CO₂ capture and sequestration. Computational studies can provide insights into MOFs and the mechanism of gas sorption and separation. Theoretical studies on existing MOFs are performed to determine what structural characteristics leads to favorable gas sorption mechanisms. The results from these studies can provide …

2,4-Disubstituted Quinazolines With Antileishmanial Or Antibacterial Activity, Megan Marie Barber

USF Tampa Graduate Theses and Dissertations

Herein 47 2,4-disubstituted quinazolines were synthesized and tested against Leishmania donovani intracellular amastigotes. A structure-activity relationship was conducted and lead to the identification of quinazolines with EC50s in the single digit and high nanomolar range with favorable antileishmanial selectivity indexes. Quinazoline 2.6 and 2.31 underwent in vivo efficacy studies in murine models of visceral leishmaniasis, reducing liver parasitemia by 12 % and 24 %, respectively, when given by the intraperitoneal route at 15 mg/kg/day x 5 days. The antileishmanial efficacy and easy of synthesis make the 2,4-disubstituted quinazoline compound series a suitable platform for the future development of antileishmanial agents. …

Glaciological Applications Of Terrestrial Radar Interferometry, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

Terrestrial Radar Interferometry (TRI) is a relatively new ground-based technique that combines the precision and spatial resolution of satellite interferometry with the temporal resolution of GPS. Although TRI has been applied to a variety of fields including bridge and landslide monitoring, it is ideal for studies of the highly-dynamic terminal zones of marine-terminating glaciers, some of which are known to have variable velocities related to calving and/or ocean-forced melting. My TRI instrument is the Gamma Portable Radar Interferometer, which operates at 17.2 GHz (1.74 cm wavelength), has two receiving antennas for DEM (digital elevation model) generation, and images the scenes …

Endocrine-Disrupting Compounds: Measurement In Tampa Bay, Removal From Sewage And Development Of An Estrogen Receptor Model, Monica Mion Cook

USF Tampa Graduate Theses and Dissertations

The significance of endocrine-disrupting compounds (EDCs) in the environment has only recently come to the forefront of scientific research, policy debates, water utilities management and public awareness. EDCs have the ability to interfere with the normal functioning of the endocrine system of humans and other animals. Numerous chemicals are included in the class of compounds known as EDCs, and exposure is widespread. These compounds are found in a variety of environmental matrices (e.g., marine and freshwater systems, sediment, soil), transported there primarily through sewage effluent discharge and recycling of sewage sludge for topical fertilizer use. This transport to the environment …

A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik

USF Tampa Graduate Theses and Dissertations

Research has long recognized and studied the dynamics of groundwater processes. More recently, groundwater dependent ecosystems (GDEs) are being recognized for their diversity and vulnerability to anthropogenic impact. Groundwater in karst landscapes presents a distinctive situation where flow through the subsurface often moves rapidly on the scale of days and weeks as opposed to years or millennia in other systems. This distinctive situation of karst systems and their vulnerability to human impacts necessitate an integrated and multifaceted approach for the management of these important resources. However, development of such an approach is complicated by the difficulty of obtaining detailed data …

Enhanced Magnetoimpedance And Microwave Absorption Responses Of Soft Ferromagnetic Materials For Biodetection And Energy Sensing, Jagannath Devkota

USF Tampa Graduate Theses and Dissertations

A combination of magnetic sensors with magnetic nanoparticles offers a promising approach for highly sensitive, simple, and rapid detection of cancer cells and biomolecules. The challenge facing the field of magnetic biosensing is the development of low-cost devices capable of superconducting quantum interference device (SQUID)-like field sensitivity at room temperature. In another area of interest, improving the sensitivity of existing electromagnetic field sensors for microwave energy sensing applications is an important and challenging task. In this dissertation, we have explored the excellent magnetoimpedance and microwave absorption responses of soft ferromagnetic amorphous ribbons and microwires for the development of high-performance magnetic …

Statistical Learning With Artificial Neural Network Applied To Health And Environmental Data, Taysseer Sharaf

USF Tampa Graduate Theses and Dissertations

The current study illustrates the utilization of artificial neural network in statistical methodology. More specifically in survival analysis and time series analysis, where both holds an important and wide use in many applications in our real life. We start our discussion by utilizing artificial neural network in survival analysis. In literature there exist two important methodology of utilizing artificial neural network in survival analysis based on discrete survival time method. We illustrate the idea of discrete survival time method and show how one can estimate the discrete model using artificial neural network. We present a comparison between the two methodology …

A Study Of Fe3O4 Magnetic Nanoparticle Rf Heating In Gellan Gum Polymer Under Various Experimental Conditions For Potential Application In Drug Delivery, Gabriel Marcus

USF Tampa Graduate Theses and Dissertations

Magnetic nanoparticles (MNPs) have found use in a wide variety of biomedical applications including hyperthermia, imaging and drug delivery. Certain physical properties, such as the ability to generate heat in response to an alternating magnetic field, make these structures ideal for such purposes. This study's objective was to elucidate the mechanisms primarily responsible for RF MNP heating and determine how such processes affect polymer solutions that might be useful in drug delivery. 15-20 nm magnetite (Fe₃O₄) nanoparticles at 0.2% and 0.5% concentrations were heated with RF fields of different strengths (200 Oe, 400 Oe and 600 …

Chemistry Graduate Teaching Assistants' Experiences In Academic Laboratories And Development Of A Teaching Self-Image, Todd Adam Gatlin

USF Tampa Graduate Theses and Dissertations

Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching.

This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each …

Exploring Variability In Population Dynamics And The Influence Of Environmental Factors On Recruitment Of An Estuarine Fish, Elizabeth Herdter Smith

USF Tampa Graduate Theses and Dissertations

The focus of this dissertation was to explore variability in population dynamics and environmental factors influential to recruitment of spotted seatrout in Florida with the end goal of testing the incorporation of select environmental variables into the current regional stock assessment models for spotted seatrout. In Chapter 2, I compared the age and size structure of six estuary populations of this species and determined whether there was significant spatial covariation in recruitment. The results of this chapter indicated that the dynamics of each local estuary population are governed more likely by environmental factors than genetic similarities. Further, they suggest that …

High Dimensional Non-Linear Optimization Of Molecular Models, Joseph C. Fogarty

USF Tampa Graduate Theses and Dissertations

Molecular models allow computer simulations to predict the microscopic properties of macroscopic systems. Molecular modeling can also provide a fully understood test system for the application of theoretical methods. The power of a model lies in the accuracy of the parameter values which govern its mathematical behavior. In this work, a new software, called ParOpt, for general high dimensional non-linear optimization will be presented. The software provides a very general framework for the optimization of a wide variety of parameter sets. The software is especially powerful when applied to the difficult task of molecular model parameter optimization. Three applications of …

Evaluation And Application Of Instruments Measuring Spatial Ability And Attitude For College Chemistry Students, Xiaoying Xu

USF Tampa Graduate Theses and Dissertations

Student performance in college chemistry courses remains a concern for educators seeking to help improve the future STEM workforce. Besides math ability and prior chemistry knowledge, spatial ability and attitude toward chemistry have been considered as important factors influencing college chemistry performance. This work includes five studies and uses data collected from instruments to examine the relationships of these two factors - spatial ability and attitude - with student chemistry performance, and provides psychometric evidence for using the Purdue Visualization of Rotations test (ROT) and Attitude toward the Subject of Chemistry Inventory (ASCIv2) to measure these two factors, respectively, in …

Mantle-Crust Interaction In Granite Petrogenesis In Post-Collisional Settings: Insights From The Danubian Variscan Plutons Of The Romanian Southern Carpathians, Ciprian Cosmin Stremtan

USF Tampa Graduate Theses and Dissertations

The issue of granite petrogenesis plays a key role in our overall understanding of the growth and differentiation of continents, as well as in our ability to unravel the tectonic histories of orogenic belts. Granites are ubiquitous magmatic products found in almost all tectonic settings: oceanic and continental rifts (i.e., plagiogranites - extreme basalt differentiates), active continental margins (e.g,. the granitic batholiths of central and southern Andes), continent-continent collision zones (e.g., the orogenic batholiths of the Himalayas, Western Anatolia), post-collisional settings (e.g., the Variscan provinces of Europe), complex within-plates settings (e.g., Limmo massif, Afar, Ethiopia). Furthermore, granitoids are characterized by …

Co(Ii) Based Metalloradical Catalysis: Carbene And Nitrene Transfer Reactions, Joseph B. Gill

USF Tampa Graduate Theses and Dissertations

Radical chemistry has attracted a large amount of research interest over the last few decades and radical reactions have recently been recognized as powerful tools for organic synthesis. The synthetic applications of radicals have been demonstrated in many fields, including in the synthesis of complex natural products. Radical reactions have a number of inherent synthetic advantages over their ionic counterparts. For example, they typically proceed at fast reaction rates under mild and neutral conditions in a broad spectrum of solvents and show significantly greater functional group tolerance. Furthermore, radical processes have the capability of performing in a cascade fashion, allowing …

Metallopeptides From Design To Catalysis: Structure, Oxidative Activities, And Inhibition Studies Of Designed And Naturally Occurring Metallopeptides, Alaa Hassan Hashim

USF Tampa Graduate Theses and Dissertations

Structural and mechanistic complexities of copper-dioxygen systems have attracted much attention in the field of bioinorganic chemistry, both in model systems and trapped protein intermediates. The research presented herein is focused on model and naturally occurring metallopeptide systems, from its design to catalysis. Copper is used as the coordinating metal ion, with cobalt and zinc as probes for metal binding. The bioinorganic chemistry of copper proteins and its coordination and spectroscopic properties are briefly discussed in chapter 1. The next two chapters are centered on the de novo design of a minimalistic metallopeptide system with an amino acid sequence of …

Magneto-Optical Kerr Eect Study Of Magnetic Anisotropy In Soft Ferromagnets, Tatiana Marie Eggers

USF Tampa Graduate Theses and Dissertations

The continued progress of modern information technology relies on understanding the influence of magnetic anisotropy on magnetic thin films. In this work, two sources of magnetic anisotropy are examined in two different soft ferromagnets: a uniaxial anisotropy induced during the fabrication of Ni₈₀Fe₂₀ and exchange anisotropy, or exchange bias, which occurs at the interface of Ni₇₇Fe₁₄Cu₅Mo₄/Fe₅₀Mn₅₀ bilayer. A home-built Magneto-optical Kerr effect magnetometer is used to measure the magnetic response of the soft ferromagnetic films and details of its construction are also discussed. A simple model …