Physical Sciences and Mathematics Commons^™

The Effect Of Processing Conditions On The Energetic Diagram Of Cdte Thin Films Studied By Photoluminescence, Shamara P. Collins

USF Tampa Graduate Theses and Dissertations

The photovoltaic properties of CdTe-based thin films depend on recombination levels formed in the CdTe layer and at the heterojunction. The localized states are resultant of structural defects (metal sublattice, chalcogen sublattice, interstitial), controlled doping, deposition process, and/or post-deposition annealing. The photoluminescence study of CdTe thin films, from both the bulk and heterojunction, can reveal radiative states due to different defects or impurities. Identification of defects allows for potential explanation of their roles and influence on solar cell performance. A thorough understanding of the material properties responsible for solar cell performance is critical in further advancing the efficiency of devices. …

An Interdisciplinary Approach To Understanding Predator-Prey Relationships In A Changing Ocean: From System Design To Education, Ileana M. Freytes-Ortiz

USF Tampa Graduate Theses and Dissertations

Climate change is ecologically and socially complex, deemed the most important issue of our generation. Through this dissertation I have approached climate change research through an interdisciplinary perspective, investigating how this phenomenon will affect marine ecological systems, how we can better develop experimental systems to answer ecological questions, and how we can effectively educate about this issue.

In Chapter 2, I provided accessible alternatives for researching the effects of climate change (elevated temperatures and pCO2) on marine ecosystems. I designed, built, and troubleshooted two accurate and inexpensive climate-controlled experimental systems capable of maintaining target conditions: a temperature-controlled system and an …

An Effectual Approach For The Development Of Novel Applications On Digital Platforms, Onkar Shamrao Malgonde

USF Tampa Graduate Theses and Dissertations

The development of novel software applications on digital platforms differs from traditional software development and provides unique challenges to the software development manager and team. Application producers must achieve application-platform match, application-market match, value propositions exceeding platform’s core value propositions, and novelty. These desired properties support a new vision of the software development team as entrepreneurs with a goal of developing novel applications on digital platforms. Digital platforms are characterized by an uncertain, risky, and resource-constrained environment, where existing approaches—plan-driven, ad-hoc, and controlled-flexible—have limited applicability. Building on the theoretical basis of the theory of effectuation from the entrepreneurship domain, this …

Offensive And Defensive Security For Everyday Computer Systems, Ian Markwood

USF Tampa Graduate Theses and Dissertations

This dissertation treats a variety of topics in the computer security domain which have direct impact on everyday life. The first extends false data injection attacks against state estimation in electric power grids and then provides a novel power flow model camouflage method to hamper these attacks. The second deals with automotive theft response, detailing a method for a car to intelligently identify when it has been stolen, based on collected behavioral traits of its driver. The third demonstrates a new attack against the content integrity of the PDF file format, caus- ing humans and computers to see different information …

Towards Fundamental Understanding Of Thermoelectric Properties In Novel Materials Using First Principles Simulations, Artem R. Khabibullin

USF Tampa Graduate Theses and Dissertations

Thermoelectric materials play an important role in energy conversion as they represent environmentally safe and solid state devices with a great potential towards enhancing their efficiency. The ability to generate electric power in a reliable way without using non-renewable resources motivates many experimentalists as well as computational physicists to search and design new thermoelectric materials. Several classes of materials have been identified as good candidates for high efficient thermoelectrics because of their inherently low thermal conductivity. The complex study of the crystal and electronic structures of such materials helps to reveal hidden properties and give fundamental understanding, necessary for the …

Orientation Invariance Methods For Inertial Gait, Ravichandran Subramanian

USF Tampa Graduate Theses and Dissertations

Intelligent devices such as smart phones, smart watches, virtual reality (VR) headsets and personal exercise devices have become integral elements of accessories used by many people. The ability of these devices to verify or identify the user could be applied for enhanced security and user experience customization among other things. Almost all these devices have built-in inertial sensors such as accelerometer and gyroscope. These inertial sensors respond to the movements made by the user while performing day to day activities like walking, getting up and sitting down. The response depends on the activity being performed and thus can be used …

Assessing Bald Cypress (Taxodium Distichum) Tree Dynamic Change In Usf Forest Preserve Area Using Mixture-Tuned Matched Filtering And Multitemporal Satellite Imagery, Yujia Wang

USF Tampa Graduate Theses and Dissertations

Wetlands are the most important and valuable ecosystems on Earth. They are called “kidneys of the Earth”. Vegetation change detection is necessary to understand the condition of a wetland and to support ecosystem sustainable management and utilization. It has been a great challenge to estimate vegetation (including bald cypress trees) coverage of the wetland because it is difficult to access directly. Satellite remote sensing technology can be one important feasible method to map and monitor changes of wetland forest vegetation and land cover over large areas. Remote sensing mapping techniques have been applied to detect and map vegetation changes in …

Comparison Of Beach Changes Induced By Two Hurricanes Along The Coast Of West-Central Florida, Ruoshu Zhao

USF Tampa Graduate Theses and Dissertations

The beach profiles pre-and post-the Hurricane Hermine (2016) and Irma (2017) along the Sand Key barrier island were collected to quantify longshore variations in storm induced beach changes as well as to compare the beach changes caused by hydrodynamic conditions of the two different hurricanes.

Cross-shore beach profile are examined in 4 sections including dune field, dry beach, sand bar and whole beach to calculate beach change. The volume change for each section and shoreline contour change before and post the hurricane was computed. Hydrodynamic conditions were obtained from adjacent NOAA’s tide and wave gauges.

Both hurricanes generated high offshore …

Particles In Welding Fumes, Rebecca T. Williams

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to investigate whether or not differing base metals and filler wires used during welding processes contributed to differing amounts of ultrafine particles (UFP) and nanoparticles being emitted during the welding procedure. The study was also conducted to determine UFP and nanoparticle exposure in the breathing zones of the welders as well as the breathing zones of pipefitters and fire watchers, who commonly sit 6ft behind the welding arc. In order to determine if UFP and NP exposures differed with base metal and filler wire, all welding processes utilized the same welding machine for metal …

New Insights On Secondary Minerals From Italian Sulfuric Acid Caves, Ilenia M. D'Angeli, Cristina Carbone, Maria Nagostinis, Mario Parise, Marco Vattano, Giuliana Madonia, Jo De Waele

International Journal of Speleology

Sulfuric acid minerals are important clues to identify the speleogenetic phases of hypogene caves. Italy hosts ~25% of the known worldwide sulfuric acid speleogenetic (SAS) systems, including the famous well-studied Frasassi, Monte Cucco, and Acquasanta Terme caves. Nevertheless, other underground environments have been analyzed, and interesting mineralogical assemblages were found associated with peculiar geomorphological features such as cupolas, replacement pockets, feeders, sulfuric notches, and sub-horizontal levels. In this paper, we focused on 15 cave systems located along the Apennine Chain, in Apulia, in Sicily, and in Sardinia, where copious SAS minerals were observed. Some of the studied systems (e.g., …

Biosorption Of Cobalt By Using Pseudomonas Aerguinosa Bacterial Strain, Abhaysinh Arvind Dharanguttikar

USF Tampa Graduate Theses and Dissertations

A study of biosorption of cobalt metal by Pseudomonas Aerguinosa gram-negative bacterial strain is presented. The present study is carried out to determine the optimum conditions of cobalt biosorption at ultra-low concentration (ppb range) in aqueous solutions. The receptiveness of cobalt metal on the extracellular surface of bacterial strain was examined by varying the pH, Initial concentration of metal and treatment time. Experimental data showed that effect of pH and treatment time is prevalent in biosorption of cobalt and by increasing both these parameters resulted in the efficient sorption of cobalt on the extracellular surface of Pseudomonas Aerguinosa. In some …

A Quantitative Analysis Of Shape Characteristics Of Marine Snow Particles With Interactive Visualization: Validation Of Assumptions In Coagulation Models, Palak P. Dave

USF Tampa Graduate Theses and Dissertations

The Deepwater Horizon oil spill that started on April 20, 2010, in the Gulf of Mexico was the largest marine oil spill in the history of the petroleum industry. There was an unexpected and prolonged sedimentation event of oil-associated marine snow to the seafloor due to the oil spill. The sedimentation event occurred because of the coagulation process among oil associated marine particles. Marine scientists are developing models for the coagulation process of marine particles and oil, in order to estimate the amount of oil that may reach the seafloor along with marine particles. These models, used certain assumptions regarding …

Chemical Investigation Of Bioactive Marine Extracts, Selam Hagos

USF Tampa Graduate Theses and Dissertations

Natural products have been a fundamental source of medicinal scaffolds for decades; with sixty percent of marketed drugs. Many synthetic chemists are focused on synthesizing potent and nontoxic compounds for pharmaceutical targets, however, nature is still proving to be a source of new bioactive compounds. Produced by the host organism for defense, reproduction and communication, secondary metabolites also demonstrate promising bioactivity against human pathogens. Hence, natural product chemists continue their quest for new leads.

As a continuation of these efforts, this thesis attempts to explore fungi and sponges for new chemistry, and ultimately, new drug candidates. Antarctica is largely untapped; …

A Comparative Study On Coastal Zone Changes And Anthropogenic Impacts Between Tampa Bay, Usa, And Xiangshan Harbor, China, During The Last 30 Years, Qiandong Guo

USF Tampa Graduate Theses and Dissertations

Currently, the U.S. and China are the two largest national economic entities in the world. However, it is noticeable that the two countries have considerably different strategies for economic development, environmental protection and land supply in coastal zones. In order to understand the coastline dynamics, land use land cover (LULC) changes and land management policies in the U.S. and China, a case study of the Tampa Bay (TB) watershed, Florida, U.S., and Xiangshan Harbor (XH), Zhejiang Province, China was conducted. The two areas possess similar humid subtropical climate and dense population, but experienced different anthropogenic impacts. TB sat at a …

An Evaluation Of Marsh Shoreline Erosion And Sediment Deposition In The Grand Bay National Estuarine Research Reserve, Mississippi, Usa, Joseph Terrano

USF Tampa Graduate Theses and Dissertations

Coastal marshes serve important ecologic and economic functions, such as providing habitat, absorbing floodwaters and storm surges, and sequestering carbon. Throughout the northern Gulf of Mexico, coastal marshes are disappearing due to wave attack, sea-level rise, sediment export, and subsidence. Marsh area increases when sediments accumulate at the marsh shoreline, accrete vertically, and when non-marsh areas are colonized by marsh vegetation. Marsh shoreline erosion results in net marsh loss when transgression rates at the marsh-water edge exceed upland-marsh migration. The balance between marsh destroying and marsh creating processes determines the long-term survivability of a marsh system. Thus, processes of shoreline …

Diversity Of Ssdna Phages Related To The Family Microviridae Within The Ciona Robusta Gut, Alexandria Creasy

USF Tampa Graduate Theses and Dissertations

The gut microbiome is a complex ecosystem of bacteria, viruses, and fungi that strongly influences animal health. The bacterial component, for example, contributes orders of magnitude more gene products to host physiology than the host genome; thus, changes to the composition of these bacterial communities can have profound influences on the health of the animal. By infecting and lysing their hosts, viruses (particularly viruses infecting bacteria or phages) can affect critical functions in these environments, yet the consequences of these infections remain to be fully described. Most studies investigating gut viromes to date have focused on double-stranded DNA (dsDNA) phages …

Environmental Controls On The Geochemistry Of Globorotalia Truncatulinoides In The Gulf Of Mexico: Implications For Paleoceanographic Reconstructions, Caitlin Elizabeth Reynolds

USF Tampa Graduate Theses and Dissertations

Modern observations of planktic foraminifera from sediment trap studies help to constrain the regional ecology of paleoceanographically valuable species. Results from a weekly-resolved sediment trap time series (2008–2014) in the northern Gulf of Mexico demonstrate that 92% of Globorotalia truncatulinoides flux occurs in winter (January, February, and March), and that encrusted and non-encrusted individuals represent calcification in distinct depth habitats. We use individual foraminiferal analysis (IFA) of G. truncatulinoides tests to investigate differences in the elemental (Mg/Ca) and isotopic composition (18O and 13C) of the encrusted and non-encrusted ontogenetic forms of G. truncatulinoides, and to estimate their calcification depth in …

Channel Camouflage And Manipulation Techniques In Wireless Networks, Song Fang

USF Tampa Graduate Theses and Dissertations

The security of wireless networks and systems is becoming increasingly important as wireless devices are more and more ubiquitous nowadays. The wireless channel exhibits the spatial uncorrelation property, which is that the characteristics of a wireless channel become uncorrelated every half carrier wavelength over distance. This property has prompted an emerging research area that utilizes wireless channel characteristics to achieve location distinction, to detect location changes or facilitate authentication of wireless users, and to establish shared secret key between legitimate communicators. This dissertation includes two work toward the security improvement of existing wireless networks and systems. With the discovered channel …

Surface And Interface Effects Of Magnetoimpedance Materials At High Frequency, Tatiana M. Eggers

USF Tampa Graduate Theses and Dissertations

Amorphous and nanocrystalline transition metal magnetic alloys (TMMAs) have been the subjects of fundamental and applied study due to their unique structure. The lack of long-range order in these materials sets the stage for their soft magnetic properties to be tuned for a variety of technological applications, such as sensitive magnetic field sensors, high frequency transformers, and stress sensors. Fundamental investigation of the magnetic and structural properties of these materials is also motivated by their unique amorphous or nanocrystalline-embedded amorphous matrix morphology, which has consequences on both the magnetism seen from both the atomic and macro-scale. The surfaces of these …

Determining Level Of Cognitive Impairment Via Computing Fractals Using A Computer, Kodhanda Karthik Siriyala

USF Tampa Graduate Theses and Dissertations

Mild Cognitive Impairment is a condition that affects an individual's thinking and decision making capabilities. Specifically, it is one where an individual's capabilities of memorizing, thinking and decision making are less efficient when compared to others. In order to diagnose this condition, a conventional method is to provide the subject with a small challenge they should be completed using pen and paper. This thesis focuses on how this method can be converted to a computer based test. A data visualization tool named Processing has been used to develop a system that runs a game-like test, which is completed by individuals …

Borromean: Preserving Binary Node Attribute Distributions In Large Graph Generations, Clayton A. Gandy

USF Tampa Graduate Theses and Dissertations

Real graph datasets are important for many science domains, from understanding epidemics to modeling traffic congestion. To facilitate access to realistic graph datasets, researchers proposed various graph generators typically aimed at representing particular graph properties. While many such graph generators exist, there are few techniques for generating graphs where the nodes have binary attributes. Moreover, generating such graphs in which the distribution of the node attributes preserves real-world characteristics is still an open challenge. This thesis introduces Borromean, a graph generating algorithm that creates synthetic graphs with binary node attributes in which the attributes obey an attribute-specific joint degree distribution. …

Sustainable Production Of Bio-Based Succinic Acid From Plant Biomass, Enlin Lo

USF Tampa Graduate Theses and Dissertations

Succinic acid is a compound used for manufacturing lacquers, resins, and other coating chemicals. It is also used in the food and beverage industry as a flavor additive. It is predominantly manufactured from petrochemicals, but it can also be produced more sustainably by fermentation of sugars from renewable feedstocks (biomass). Bio-based succinic acid has excellent potential for becoming a platform chemical (building block) for commodity and high-value chemicals.

In this study, we focused on the production of bio-based succinic acid from the fiber of sweet sorghum (SS), which has a high fermentable sugar content and can be cultivated in a …

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele

International Journal of Speleology

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, …

Ecophysiology Of Oxygen Supply In Cephalopods, Matthew A. Birk

USF Tampa Graduate Theses and Dissertations

Cephalopods are an important component of many marine ecosystems and support large fisheries. Their active lifestyles and complex behaviors are thought to be driven in large part by competition with fishes. Although cephalopods appear to compete successfully with fishes, a number of their important physiological traits are arguably inferior, such as an inefficient mode of locomotion via jet propulsion and a phylogenetically limited means of blood-borne gas transport. In active shallow-water cephalopods, these traits result in an interesting combination of very high oxygen demand and limited oxygen supply. The ability to maintain active lifestyles despite these metabolic constraints makes cephalopods …

A Key Based Obfuscation And Anonymization Of Behavior Vhdl Models, Balausha Varshini Kandikonda

USF Tampa Graduate Theses and Dissertations

Intellectual Property (IP) based Integrated Circuit (IC) design is an established approach for the design of a complex System-on-Chip (SoC). Porting the preparatory designs to third-party without enough security margin exposes an attacker to perform reverse engineering (RE) on the designs and hence counterfeiting, IP theft etc., are common now-a-days. Design obfuscation can reduce RE attempt by an attacker. In this work, we propose a key based obfuscation and anonymization method for a behavioral IP. Given a behavioral VHDL description, the assignment and conditional statements are modified by incorporating random boolean operations with unique random key bits. The obfuscated VHDL …

Underground Stormwater Treatment Performance In Urban Coastal Catchments: Case Study Of Baffle Boxes In The City Of Tampa, Awet Eyob Tsegay

USF Tampa Graduate Theses and Dissertations

In coastal urban regions, underground stormwater treatment units are suitable infrastructure options because they take less space where premium land is expensive. Even then, they should be accessible and ideally small enough to fit into existing stormwater networks. Since 2003, the City of Tampa and Florida’s Department of Transportation (FDOT) have installed 47 baffle boxes into the city’s stormwater pipe networks. Baffle boxes are underground stormwater treatment structures designed to capture sediments and floating debris. Since their deployment, many challenges regarding their practical sediment capturing performance was raised by the city.

The objective of this research was to evaluate the …

Full Issue 47(2)

International Journal of Speleology

No abstract provided.

Table Of Contents

International Journal of Speleology

No abstract provided.

Quantitative Proteomics To Support Translational Cancer Research, Melissa Hoffman

USF Tampa Graduate Theses and Dissertations

Altered signaling pathways, which are mediated by post-translational modifications and changes in protein expression levels, are key regulators of cancer initiation, progression, and therapeutic escape. Many aspects of cancer progression, including early carcinogenesis and immediate response to drug treatment, are beyond the scope of genetic profiling and non-invasive monitoring techniques. Global protein profiling of cancer cell line models, tumor tissues, and biofluids (e.g. serum or urine) using mass spectrometry-based proteomics produces novel biological insights, which support improved patient outcomes. Recent technological advances resulting in next-generation mass spectrometry instrumentation and improved bioinformatics workflows have led to unprecedented measurement reproducibility as well …

Ripple Effects Of The Belo Monte Dam: A Syndemic Approach To Addressing Health Impacts For The Downstream Community Of Gurupá, Cynthia A. Pace

USF Tampa Graduate Theses and Dissertations

This dissertation examines the public health impacts of a large dam project on a downstream community using the framework of Syndemic Theory. The particular focus is the Belo Monte Dam, located in the Brazilian Amazon, and its impact on the community of Gurupá, Pará. At the present time the Belo Monte Dam, which is nearing completion, stands out in scale as being the world’s third largest dam complex. Gurupá is a community well known (and well-studied) in the social science literature as Amazon Town. The aims of this study are to assess the pre-existing public health of Gurupá, as well …