Physical Sciences and Mathematics Commons^™

An Investigation Of The Effects Of Chemical And Physical Weathering On Submerged Karst Surfaces, Bryan Charles Booth

USF Tampa Graduate Theses and Dissertations

Reports an investigation of the effects of chemical and physical weathering on submerged karst surfaces that pairs laboratory studies with computer modeling studies. The first study attempts to quantify the production of carbonate fines; soluble sediments produced by the incomplete dissolution of karst minerals during chemical weathering. Results show carbonate fine production in relation to dissolutional action; Chalk: 42.8%; Coquina: 2.6%; Dolomite: 3.1%; Gray Limestone: 4.8%; Ocala Limestone: 3.1%; Shell Limestone: 6.1%; Travertine: 8.6%. Due to the use of hydrochloric acid as opposed to carbonic acid these results may not be fully valid for application to natural speleogenic processes. The …

Synthesis Of Agents For The Treatment And Analysis Of Tropical Diseases, Jeanine Yacoub

USF Tampa Graduate Theses and Dissertations

Toxoplasmosis is an opportunistic disease caused by the protozoan parasite Toxoplasma gondii. The parasite is usually staved off by a healthy immune system and remains dormant in the body. In immunocompromised patients, the parasite can become active and spread throughout the body causing symptoms such as encephalitis, cognitive disorders, seizures, and death. Combination drug therapy is the usual treatment for toxoplasmosis; however, patients suffer from problems of intolerance, allergic reactions, and cytotoxicity. In an effort to identify new drug targets for toxoplasmosis, a series of compounds have been synthesized that can be used as tools to probe the unique …

The Relationship Of Childhood Stress To Adult Health And Mortality Among Individuals From Two U.S. Documented Skeletal Collections, Late 19Th To Early 20Th Centuries, Rhonda Coolidge

USF Tampa Graduate Theses and Dissertations

Although the association between social inequality and poor adult health is well established, the mechanisms by which inequality is translated into poor adult health are less clear. Increasingly, evidence suggests that many adult health problems and health disparities have their origins in early life; the developmental origins of health and disease (DOHaD) hypothesis provides an explanatory mechanism linking adverse early life conditions with permanent structural or functional changes that increase the risk for disease. This hypothesis is consistent with bioarchaeological research noting reduced lifespan among individuals exhibiting signs of childhood stress.

The principal aim of this dissertation is to contribute …

Multiple Scales Of Beach Morphodynamic Processes: Measurements And Modelling, Jun Cheng

USF Tampa Graduate Theses and Dissertations

Multiple scales of beach morphodynamic processes ranging from those of wave-breaking induced turbulence, individual wave, storm, seasonal, to inter-annual are examined in this dissertation based on both laboratory and field data. These processes were simulated using process-based numerical models and data-driven models.

At a microscale, separating turbulence from orbital motion under breaking waves in the surf zone is essential to understanding wave-energy dissipation. Velocity data under monochromatic and random waves in the large-scale sediment transport facility (LSTF) were analyzed. Moving averaging provides a simple method for extracting turbulence from velocity measurements under random breaking waves collected at a reasonably high …

Optical Communication Using Hybrid Micro Electro Mechanical Structures (Mems) And Commercial Corner Cube Retroreflector (Ccr), Sunny Kedia

USF Tampa Graduate Theses and Dissertations

This dissertation presents a free-space, long-range, passive optical communication system that uses electrostatically modulated microelectromechanical systems (MEMS) structures coupled with a glass total internal reflection (TIR)-type corner cube retroreflector (CCR) as a non-emitting data transmitter. A CCR consists of three mirrors orthogonal to each other, so that the incident beam is reflected back to the incident beam, source. The operational concept is to have a MEMS modulator fusion with TIR CCR, such that the modulators are working periodically to disrupt the evanescent waves at the air interface of one of the three back glass faces of a TIR CCR. The …

Direct Solutions To Perceptual Organization Problems, Ravi Kumar Panchumarthy

USF Tampa Graduate Theses and Dissertations

Quadratic optimization problems arise in various real world application domains including engineering design, microeconomics, genetic algorithms, integrated circuit chip design, probabilistic graphical models and computer vision. In particular, there are many problems in computer vision that require binary quadratic optimization such as motion segmentation, correspondences, figure-ground segmentation, clustering, grouping, subgraph matching, and digital matting. The objective of an optimization algorithm can be related to the state of a physical system, where the goal is to bring the initial arbitrary state of the system to a state with minimum possible energy. By recognizing that the Hamiltonian of nanomagnets can be expressed …

Predictive Analytics Of Organizational Decisions And The Role Of Rationality, Arash Barfar

USF Tampa Graduate Theses and Dissertations

How can we predict key decisions made by organizations in the presence of big data and on-demand information? In this dissertation we exploit a large repository of B2B real-time transactional data with service quality indicators and present evidence that organizational decision analytics apply both rational and boundedly-rational (i.e. behavioral) economic models. The dissertation’s findings demonstrate that both utility and heuristic models, respectively, play significant roles in predicting organizational decisions on churn, a key decision in this context. In the presence of a large data set the assumed rationality of organizations appears to provide accurate predictions in uncontrolled experiences and selected …

A Comparative Analysis Of Portable X-Ray Fluorescence Spectrometry And Stable Isotopes In Assessing Ancient Coastal Peruvian Diets, Theresa Jane Gilbertson

USF Tampa Graduate Theses and Dissertations

This dissertation explores a cross-cultural analysis of the dietary signatures of four coastal cultures of prehistoric Peru. A combination of elemental analysis based on portable x-ray fluorescence spectrometry (pXRF), testing trace elements presented in 209 individuals’ skulls representing the Nazca (38), Cañete (33), Lima (40), and Moche (98) valleys and/or cultures of the first millennium AD, is weighed in conjunction with isotope ratio mass spectrometry (IRMS) to analyze human bone collagen and bone apatite derived from a portion of the individuals represented in the Nazca, Cañete, and Lima cranial samples.

Evidence from the results of both tests are weighed using …

In Vacuo Fabrication And Electronic Structure Characterization Of Atomic Layer Deposition Thin Films, Michael Schaefer

USF Tampa Graduate Theses and Dissertations

Improvement of novel electronic devices is possible by tailor-designing the electronic structure at device interfaces. Common problems observed at interfaces are related to unwanted band alignment caused by the chemical diversity of interface partners, influencing device performance negatively. One way to address this problem is by introducing ultra-thin interfacial dipole layers, steering the band alignment in a desired direction. The requirements are strict in terms of thickness, conformity and low density of defects, making sophisticated deposition techniques necessary. Atomic layer deposition (ALD) with its Ångstrom-precise thickness control can fulfill those requirements.

The work presented here encompasses the implementation of an …

Investigation Of The Mechanisms For Mobilization Of Arsenic In Two Asr Systems In Southwest Central Florida, Gregg William Jones

USF Tampa Graduate Theses and Dissertations

Aquifer storage and recovery (ASR) is a strategy in which water is injected into an aquifer when it is plentiful and pumped from the aquifer when water is scarce. An impediment to ASR in Florida is leaching of naturally-occurring arsenic from limestone of the Upper Floridan Aquifer System (UFAS) into stored water. The concentration of arsenic in surface water, which serves as the recharge water for many ASR systems, and native groundwater is usually much less than 3.0 µ/L. However, data from ASR wells in Florida show that arsenic in recovered water frequently exceeded the 10 µg/L maximum contaminant level …

Investigation Of Low Thermal Conductivity Materials With Potential For Thermoelectric Applications, Kaya Wei

USF Tampa Graduate Theses and Dissertations

Thermoelectric devices make it possible for direct energy conversion between heat and electricity. In order to achieve a high energy conversion efficiency, materials with a high thermoelectric figure of merit (ZT = S²σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity) are in great demand. The standard approach is to optimize charge carrier transport while at the same time scatter the heat transport, a task that is easier said than done. Improving the electrical properties in order to increase ZT is limited since electrons …

A Theoretical And Methodological Framework To Analyze Long Distance Pleasure Travel, Vijayaraghavan Sivaraman

USF Tampa Graduate Theses and Dissertations

The United States (US) witnessed remarkable growth in annual long distance travel over the past few decades. Over half of the long distance travel in the US is made for pleasure, including visiting friends and relatives (VFR) and leisure activities. This trend could continue with increased use of information and communication technologies for socialization, and enhanced mobility being achieved using fuel-efficient (electric/hybrid) and technology enhanced vehicles. Despite these developments, and recent interest to implement alternate mass transit options to serve this market, not much exists on the measurement, analysis and modeling of long distance pleasure travel in the U.S.

Statewide …

Pathogen Removal In Natural Wastewater Treatment And Resource Recovery Systems: Solutions For Small Cities In An Urbanizing World, Matthew Eric Verbyla

USF Tampa Graduate Theses and Dissertations

Sanitation, renewable energy, and food security are among the most pressing global development needs of the century, especially for small cities with rapid population growth. Currently, 53% of the world’s population either lacks access to improved sanitation or discharges fecal waste to the environment without treatment. Furthermore, 80% of food consumed in developing regions is produced by 500 million small farms, and while many of them are still rain-fed, irrigated agriculture is increasing. The post-2015 Sustainable Development Goals, recently adopted by the United Nations, include targets to address the water-energy-food nexus. Wastewater reuse in agriculture can be an important solution …

Computational Methods For Biomarker Identification In Complex Disease, Amin Ahmadi Adl

USF Tampa Graduate Theses and Dissertations

In a modern systematic view of biology, cell functions arise from the interaction between molecular components. One of the challenging problems in systems biology with high-throughput measurements is discovering the important components involved in the development and progression of complex diseases, which may serve as biomarkers for accurate predictive modeling and as targets for therapeutic purposes. Due to the non-linearity and heterogeneity of these complex diseases, traditional biomarker identification approaches have had limited success at finding clinically useful biomarkers. In this dissertation we propose novel methods for biomarker identification that explicitly take into account the non-linearity and heterogeneity of complex …

Content Abuse And Privacy Concerns In Online Social Networks, Md Imrul Kayes

USF Tampa Graduate Theses and Dissertations

Online Social Networks (OSNs) have seen an exponential growth over the last decade, with Facebook having more than 1.49 billion monthly active users and Twitter having 135,000 new users signing up every day as of 2015. Users are sharing 70 million photos per day on the Instagram photo-sharing network. Yahoo Answers question-answering community has more than 1 billion posted answers. The meteoric rise in popularity has made OSNs important social platforms for computer-mediated communications and embedded themselves into society’s daily life, with direct consequences to the offline world and activities. OSNs are built on a foundation of trust, where users …

Novel Enzyme Perspectives: Arylalkylamine N-Acyltransferases From Bombyx Mori & 1-Deoxy- D-Xylulose-5-Phosphate Synthase From Plasmodium Falciparum And Plasmodium Vivax, Matthew R. Battistini

USF Tampa Graduate Theses and Dissertations

This dissertation is dedicated to the research and investigation of novel enzymes and the methods used to study them, with physiological roles ranging from isoprenoid biosynthesis to neurotransmitter production. Using a combination of bioinformatics, recombinant cloning, enzymology, and proteomics, we have contributed to the understanding and exploration of several human illnesses, including malaria, cancer, and endocrine dysfunction.

Our first project involved studying the enzymes responsible for N-acylarylalkylamide biosynthesis in Bombyx mori. Very little is known how these potent signaling molecules are produced in vivo, however, one possible pathway is the direct conjugation of an acyl-CoA to a corresponding …

Phosphorus Sorption Dynamics In Shallow Groundwater, Coastal Everglades, Florida, Usa, Hilary Flower

USF Tampa Graduate Theses and Dissertations

For this dissertation I studied phosphorus (P) sorption dynamics in the shallow groundwater of the southern Everglades. In particular, I examined how the ambient water type governs soluble reactive P (SRP) availability through adsorption/desorption reactions with the aquifer matrix. Chapter 2 investigated how P sorption dynamics of the mangrove root zone sediment are affected by high bicarbonate brackish groundwater compared to both fresh groundwater and saltwater. The results from chapter 2 show that the sediment exhibited exceptionally low sorption efficiency in the high bicarbonate brackish water, which would allow ambient water SRP concentration to be maintained at a higher level. …

Precise Detection Of Injection Attacks On Concrete Systems, Clayton Whitelaw

USF Tampa Graduate Theses and Dissertations

Injection attacks, including SQL injection, cross-site scripting, and operating system command injection, rank the top two entries in the MITRE Common Vulnerability Enumeration (CVE) [1]. Under this attack model, an application (e.g., a web application) uses some untrusted input to produce an output program (e.g., a SQL query). Applications may be vulnerable to injection attacks because the untrusted input may alter the output program in malicious ways. Recent work has established a rigorous definition of injection attacks. Injections are benign iff they obey the NIE property, which states that injected symbols strictly insert or expand noncode tokens in the output …

A Study On The Integration Of Multivariate Metocean, Ocean Circulation, And Trajectory Modeling Data With Static Geographic Information Systems For Better Marine Resources Management And Protection During Coastal Oil Spill Response – A Case Study And Gap Analysis On Northeastern Gulf Of Mexico Tidal Inlets, Richard Ray Knudsen

USF Tampa Graduate Theses and Dissertations

The Oil Pollution Act of 1990 requires the development of Regional and Area Contingency Plans. For more than 20 years, the State of Florida, under both the Department of Environmental Protection and the Florida Fish and Wildlife Commission, has worked closely with the U.S. Coast Guard and the National Oceanic and Atmospheric Administration to develop these plans for coastal and marine oil spill response. Current plans, developed with local, state and federal stakeholder input, use geographic information systems (GIS) data such as location and extent of sensitive ecological, wildlife, and human-use features (termed Environmental Sensitivity Index data), pre-defined protection priorities, …

Understanding Climate Change And Sea Level: A Case Study Of Middle School Student Comprehension And An Evaluation Of Tide Gauges Off The Panama Canal In The Pacific Ocean And Caribbean Sea, Juan Carlos Millan-Otoya

USF Tampa Graduate Theses and Dissertations

The present study had two main objectives. The first was to determine the degree of understanding of climate change, sea level and sea level rise among middle school students. Combining open-ended questions with likert-scaled questions, we identified student conceptions on these topics in 86 students from 7^th and 8^th grades during 2012 and 2013 before and after implementing a Curriculum Unit (CU). Additional information was obtained by adding drawings to the open-ended questions during the second year to gauge how student conceptions varied from a verbal and a visual perspective. Misconceptions were identified both pre- and post-CU among …

Analysis Of Rheumatoid Arthritis Data Using Logistic Regression And Penalized Approach, Wei Chen

USF Tampa Graduate Theses and Dissertations

In this paper, a rheumatoid arthritis (RA) medicine clinical dataset with an ordinal response is selected to study this new medicine. In the dataset, there are four features, sex, age,treatment, and preliminary. Sex is a binary categorical variable with 1 indicates male, and 0 indicates female. Age is the numerical age of the patients. And treatment is a binary categorical variable with 1 indicates has RA, and 0 indicates does not have RA. And preliminary is a five class categorical variable indicates the patient’s RA severity status before taking the medication. The response Y is 5 class ordinal variable shows …

Comparison Of Otolith-Based Growth Rates And Microchemistry In Red Drum Before, During, And After The Deepwater Horizon Oil Spill, Brock Charles Houston

USF Tampa Graduate Theses and Dissertations

Oil from the Deepwater Horizon blowout reached the Gulf of Mexico coast in the summer of 2010 and potentially exposed species living in those areas to toxic chemicals. The purpose of this study is to examine otoliths from Red Drum (Sciaenops ocellatus) for evidence of oil exposure that could be related to reduced growth rates. Because otolith growth and somatic growth are directly related, differences in annulus measurements can indicate differences in annual somatic growth, which is a good indicator of overall fish condition, and translates into changes in survival and lifetime reproductive potential. This study assessed variation …

A Comparative Study Of Formal Verification Techniques For Authentication Protocols, Hernan Miguel Palombo

USF Tampa Graduate Theses and Dissertations

Protocol verification is an exciting area of network security that intersects engineering and formal methods. This thesis presents a comparison of formal verification tools for security protocols for their respective strengths and weaknesses supported by the results from several case studies. The formal verification tools considered are based on explicit model checking (SPIN), symbolic analysis (Proverif) and theorem proving (Coq). We formalize and provide models of several well-known authentication and key-establishment protocols in each of the specification languages, and use the tools to find attacks that show protocols insecurity. We contrast the modelling process on each of the tools by …

Influence Of Water Column Stratification And Nutrient Gradients On The Migratory Behavior Of The Red Tide Dinoflagellate, Karenia Brevis, Matthew Garrett

USF Tampa Graduate Theses and Dissertations

Diel vertical migration (DVM) can offer motile phytoplankton a competitive advantage over other phytoplankton species. DVM has been well documented in the harmful dinoflagellate, Karenia brevis; however, the extent to which changes in nutrient regimes and density stratification modify migration patterns has not been thoroughly investigated. A 2 m experimental column was constructed with sensors and sampling ports at four depths to obtain fluorescence and temperature measurements and discrete water samples. The environmental parameters of the experimental column represented temperature and nutrient conditions found on the West Florida Shelf (WFS), where Karenia blooms frequently occur. Results demonstrated a clear …

Is Nubia Plate Rigid? A Geodetic Study Of The Relative Motion Of Different Cratonic Areas Within Africa., Mary Wambui Njoroge

USF Tampa Graduate Theses and Dissertations

The Nubia plate is normally considered to be a rigid plate and as such used in the realization of terrestrial reference frame. Gondwana breakup plate reconstruction, the Cameroon volcanic line, seismicity, and the morphology of the Okavango rift zone (ORZ) suggest the presence of internal deformation within the Nubia plate. To test this hypothesis, six different reference frames were developed from the velocity field of three individual regions (West, Central and South), and of different combinations of them (West+Central, South+Central, and Nubia as a whole). The residual velocities with respect to these references frame help us understand the presence of …

The Development Of A Fluorescence-Based Reverse Flow Injection Analysis (Rfia) Method For Quantifying Ammonium At Nanomolar Concentrations In Oligotrophic Seawater, William Abbott

USF Tampa Graduate Theses and Dissertations

The goal of this thesis was to adopt a reverse flow injection analysis (rFIA) technique to the fluorometric analysis of the reaction o-phthaldialdehyde (OPA) with ammonium, allowing accurate measurements of ammonium concentrations lower than the detection limit of the widely used indophenol blue (IPB) colorimetric method while accounting for the background fluorescence of seawater. Ammonium is considered an essential nutrient for primary productivity, especially in the nutrient depleted surface ocean where as the most reduced form of dissolved inorganic nitrogen, it is readily assimilated via metabolic pathways. Challenges in the quantification of ammonium require more sensitive analytical techniques for …

Geophysical Evidence For Mid-Crustal Magma Reservoirs In The Lassen Volcanic Region, California, Samantha Catherine Tavarez

USF Tampa Graduate Theses and Dissertations

Regional-scale complete Bouguer gravity anomalies underlying the Lassen and Shasta -Medicine Lake regions in northern California and southern Oregon are associated with subduction of the Gorda plate beneath North America. These generally negative anomalies reflect where underplating has deepened to form the mantle wedge, and where subduction has given rise to a series of Quaternary volcanoes comprising the southernmost end of the Cascade range. Multiple conductive bodies were identified by Park and Ostos (2013) in their magnetotelluric (MT) study of the broader Lassen volcanic region. Their broadband and long period measurements were conducted along a 250 km profile spanning from …

Ensemble Learning Method On Machine Maintenance Data, Xiaochuang Zhao

USF Tampa Graduate Theses and Dissertations

In the industry, a lot of companies are facing the explosion of big data. With this much information stored, companies want to make sense of the data and use it to help them for better decision making, especially for future prediction. A lot of money can be saved and huge revenue can be generated with the power of big data. When building statistical learning models for prediction, companies in the industry are aiming to build models with efficiency and high accuracy. After the learning models have been developed for production, new data will be generated. With the updated data, the …

Synthesis, Characterization And Ferroelectric Properties Of Ln-Type Znsno3 Nanostructures, Corisa Kons

USF Tampa Graduate Theses and Dissertations

With increasing focus on the ill health and environmental effects of lead there is a greater push to develop Pb-free devices and materials. To this extent, ecofriendly and earth abundant LiNbO₃-type ZnSnO₃, a derivative of the ABO₃ perovskite structure, has a high theoretically predicted polarization making it an excellent choice as a suitable alternative to lead based material such as PZT. In this work we present a novel synthesis procedure for the growth of various ZnSnO₃ nanostructures by combined physical/chemical processes. Various ZnSnO₃ nanostructures of different dimensions were grown from a ZnO:Al template …

Operation And Monitoring Of Parabolic Trough Concentrated Solar Power Plant, Harsha Vardhan Amba

USF Tampa Graduate Theses and Dissertations

The majority of the power generated today is produced using fossil fuels,emitting carbon dioxide and other pollutants every second. Also, fossil fuels will eventually run out. For the increasing worldwide energy demand, the use f reliable and environmentally beneficial natural energy sources is one of the biggest challenges. Alongside wind and water, the solar energy which is clean, CO2-neutral and limitless, is our most valuable resource.

Concentrated solar power (CSP) is becoming one of the excellent alternative sources for the power industry. The successful implementation of this technology requires the efficient design of tracking and operation system of the CSP …