Physical Sciences and Mathematics Commons^™

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 …

Cultivating Local: Building A Local Food System In Western North Carolina, Allison S. Perrett

USF Tampa Graduate Theses and Dissertations

This dissertation examines a movement in Western North Carolina to build a local food system, one grounded in the conditions and relationships of place. In 2000, Mountain Family Farms launched the Local Food Campaign to raise public awareness about the region's farms and farming heritage, to educate consumers about the benefits of buying food grown by local farms, and, ultimately, to build markets for locally grown food to sustain the region's farms. The campaign sparked a social movement and over a decade later local farms and locally grown food are a palpable feature of life in the mountains of Western …

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 …

Novel Models And Algorithms For Uncertainty Management In Power Systems, Long Zhao

USF Tampa Graduate Theses and Dissertations

This dissertation is a collection of previously-published manuscript and conference papers. In this dissertation, we will deal with a stochastic unit commitment problem with cooling systems for gas generators, a robust unit commitment problem with demand response and uncertain wind generation, and a power grid vulnerability analysis with transmission line switching. The latter two problems correspond to our theoretical contributions in two-stage robust optimization, i.e., how to efficiently solve a two-stage robust optimization, and how to deal with mixed-integer recourse in robust optimization. Due to copyright issue, this dissertation does not include any methodology papers written by the author during …

Control Of Smart Building Using Advanced Scada, Vivin Thomas Samuel

USF Tampa Graduate Theses and Dissertations

ABSTRACT

For complete control of the building, a proper SCADA implementation and the optimization strategy has to be build. For better communication and efficiency a proper channel between the Communication protocol and SCADA has to be designed.

This paper concentrate mainly between the communication protocol, and the SCADA implementation, for a better optimization and energy savings is derived to large scale industrial buildings. The communication channel used in order to completely control the building remotely from a distant place. For an efficient result we consider the temperature values and the power ratings of the equipment so that while controlling the …

Assessing Hurricane Preparedness Among Residential Staff At Louisiana State University: A Case Study On Hurricane Isaac, Ashley Marie Weatherall

USF Tampa Graduate Theses and Dissertations

Studying hurricane preparedness among the Resident Assistants (RAs) and Residence Life Coordinators (RLCs) at Louisiana State University (LSU) is imperative to assure that the university housing staff is fully equipped when faced with an oncoming threat. This study seeks to fill a gap in research by investigating the influences of preparedness on student housing employees. A survey was developed and the measures were found to be coherent and internally reliable through the use of factor analysis. Based on theory and previous literature, a linear regression model was developed that quantified the relationship between the independent variable of preparedness and general …

Exploring Local Food System Practices And Perceptions: Insights From Florida's Snap-Authorized Farmers' Markets, Leslie Babiak

USF Tampa Graduate Theses and Dissertations

Despite heightened interest in creating local food systems that enhance health of ecologies, economies, and all members of communities, the public space of farmers' markets is far less than inherently equitable. This is particularly concerning given America's unprecedented crisis of food hardship and related disease, which disproportionately affects lower income populations. This research addresses the social justice implications of SNAP (food stamp) operations for locally oriented food systems. Pioneering practices of three of Florida's SNAP-authorized farmers' markets, and the attitudes and behaviors of one-hundred-seventy-six market patrons, were explored through customer surveys, market manager interviews, and environmental assessments. Qualitative and quantitative …

Weather Patterns Associated With Green Turtle Hypothermic Stunning Events In St. Joseph Bay And Mosquito Lagoon, Florida, Kelsey Roberts

USF Tampa Graduate Theses and Dissertations

January of 2010 brought record-breaking cold temperatures to Florida. Such freeze events can upset vulnerable populations of marine life and other species that rely on stable water temperatures. Sea turtles are one group of species that are particularly susceptible to abrupt drops in water temperature. When water temperatures drop below 10°C, a mass hypothermic stunning, or cold-stunning, event for sea turtles can be expected, with many debilitated turtles washing onshore with a very limited time window to be rehabilitated (Foley et al. 2007). The species of sea turtle that appears to cold-stun with the most frequency is the green turtle, …

Investigation Of Colored Dissolved Organic Matter (Cdom) Optical Properties, Nutrients, And Salinity In Coastal Florida: Springshed To Estuaries, Ana Rosa Arellano

USF Tampa Graduate Theses and Dissertations

Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal …

Fate Of Polybrominated Diphenyl Ethers During Wastewater Treatment Process Producing Reclaimed Water, Kristy Siegel

USF Tampa Graduate Theses and Dissertations

Polybrominated diphenyl ethers (PBDEs), flame retardants, have been applied to consumer goods, such as furniture, electrical devices, textiles, and appliances for decades. Due to their physico-chemical properties, PBDEs are semi-volatile and easily leach off the consumer good during aging, stress, or normal wear and tear of the good. Once airborne, they pose an environmental health threat because they can adsorb onto dust particles, soil, or other particulates that can be inhaled, ingested, or come into contact with the dermal layer. Additionally, PBDEs have a molecular structure similar to other persistent organic pollutants, such as polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and …

The Water Culture Beliefs Of Embera Communities And Maternal And Child Health In The Republic Of Panama, Ilenia Anneth Forero

USF Tampa Graduate Theses and Dissertations

Water has cultural and spiritual values to indigenous people. These beliefs expose them to unsafe water sources and make them vulnerable to waterborne diseases. This background is not taken into account when countries write their water legislations, therefor imposing a management of water not readily accepted by them. The Embera group is one of the indigenous groups from the Republic of Panama, who have strong water beliefs. They live along the shore of rivers in houses built on high stilts away from urban areas. The purpose of this cross-sectional community based study is to describe through a survey the relation …

Spatial Distribution Of Nitrogen Oxides, Benzene, Toluene, Ethylbenzene, And Xylenes In Hillsborough County, Florida: An Investigation Of Impacts Of Urban Forests On Ambient Concentrations Of Air Pollutants Associated With Traffic, Jill Sears

USF Tampa Graduate Theses and Dissertations

Urban air pollution is responsible for high levels of morbidity and mortality in exposed populations due to its effects on cardiovascular and respiratory function. Transportation-related air pollutants account for the majority of harmful air pollution in urban areas. Forests are known to reduce air pollution through their ability to facilitate dry deposition and atmospheric gas exchange. This work characterizes the interactions between transportation air pollutants and urban forests in Hillsborough County, Florida. A highly spatially resolved passive air sampling campaign was conducted to characterize local concentrations of nitrogen oxides, benzene, toluene, ethylbenzene, and xylenes (BTEX) in Hillsborough County, Florida. Sampling …

Investigation Of Mercury Use, Release, Deposition, And Exposures In The Tampa Bay Area, Ryan Algernon Michael

USF Tampa Graduate Theses and Dissertations

I investigate the links between mercury use, release, deposition, and population exposure in Tampa Bay, with the focus of identifying levers for reducing population mercury exposures. To achieve this, I investigated the trends in mercury use and release by products and processes in the Tampa Bay area using a Material Flow Analysis. Analysis of USEPA National Emissions Inventory data over time (1999 - 2008) identified relevant air source emission categories, and explored and compared state and regional trends in mercury emissions. To understand source contributions to wet deposited mercury in the Tampa Bay area, I analyzed trends in mercury deposition …

Agricultural And Domestic Waste Contamination In Chilibre Panama And Potential Low-Cost Best Managament Practices, Christopher Etienne Weekes

USF Tampa Graduate Theses and Dissertations

Abstract

Sanitation coverage in the Republic of Panama is 5 to 10 percent below the Millennium Development Goals targets set for the country. Population growth, urbanization, unplanned development and waste mismanagement have resulted in improvised trash sites and waste discharges into river systems that are important components of the biologically diverse natural environment of Panama. The study sought to investigate and estimate the burden of waste from domestic and agricultural sources in three regions of the Chilibre corrigimiento (district). It was hypothesized that the water quality and land cover data would reflect that the most populated region in the study …

A Modeling Investigation Of Human Exposure To Select Traffic-Related Air Pollutants In The Tampa Area: Spatiotemporal Distributions Of Concentrations, Social Distributions Of Exposures, And Impacts Of Urban Design On Both, Haofei Yu

USF Tampa Graduate Theses and Dissertations

Increasing vehicle dependence in the United States has resulted in substantial emissions of traffic-related air pollutants that contribute to the deterioration of urban air quality. Exposure to urban air pollutants trigger a number of public health concerns, including the potential of inequality of exposures and health effects among population subgroups. To better understand the impact of traffic-related pollutants on air quality, exposure, and exposure inequality, modeling methods that can appropriately characterize the spatiotemporally resolved concentration distributions of traffic-related pollutants need to be improved. These modeling methods can then be used to investigate the impacts of urban design and transportation management …

Development Of Nanostructured Graphene/Conducting Polymer Composite Materials For Supercapacitor Applications, Punya A. Basnayaka

USF Tampa Graduate Theses and Dissertations

The developments in mobile/portable electronics and alternative energy vehicles prompted engineers and researchers to develop electrochemical energy storage devices called supercapacitors, as the third generation type capacitors. Most of the research and development on supercapacitors focus on electrode materials, electrolytes and hybridization. Some attempts have been directed towards increasing the energy density by employing electroactive materials, such as metal oxides and conducting polymers (CPs). However, the high cost and toxicity of applicable metal oxides and poor long term stability of CPs paved the way to alternative electrode materials. The electroactive materials with carbon particles in composites have been used substantially …

Application And Characterization Of Self-Assembled Monolayers In Hybrid Electronic Systems, Michael Enoch Celesin

USF Tampa Graduate Theses and Dissertations

In this study, we explore ultra-thin insulators of organic and inorganic composition and their potential role as high-speed rectifiers. Typical applications for these structures include IR sensing, chemical detection, high speed logic circuits, and MEMS enhancements. While there are many elements in the functional group required to create a rectifying antenna (rectenna), the primary thrust of this work is on the rectifier element itself.

To achieve these research goals, a very good understanding of quantum tunneling was required to model the underlying phenomenon of charge conduction. The development of a multi-variable optimization routine for tunneling prediction was required. MATLAB was …

Relative Survival Of Gags Mycteroperca Microlepis Released Within A Recreational Hook-And-Line Fishery: Application Of The Cox Regression Model To Control For Heterogeneity In A Large-Scale Mark-Recapture Study, Beverly J. Sauls

USF Tampa Graduate Theses and Dissertations

The objectives of this study were to measure injuries and impairments directly observed from gags Mycteroperca microlepis caught and released within a large-scale recreational fishery, develop methods that may be used to rapidly assess the condition of reef fish discards, and estimate the total portion of discards in the fishery that suffer latent mortality. Fishery observers were placed on for-hire charter and headboat vessels operating in the Gulf of Mexico from June 2009 through December 2012 to directly observe reef fishes as they were caught by recreational anglers fishing with hook-and-line gear. Fish that were not retained by anglers were …

Hydrogen Storage In Hypercrosslinked Polystyrene And Li-Mg-N-H Complex Hydride, Dervis Emre Demirocak

USF Tampa Graduate Theses and Dissertations

In this dissertation, hydrogen storage enhancement in hypercrosslinked polystyrene, effects of single walled carbon nanotubes (SWCNTs) supported ruthenium (Ru) catalyst on the kinetics and ammonia suppression in the LiNH2-MgH2 complex hydride system and the accuracy of hydrogen storage measurements are investigated in detail.

High surface area physisorption materials are of interest for room temperature hydrogen storage enhancement by spillover. Six different commercially available hypercrosslinked polystyrenes are screened by considering the specific surface area, average pore size, pore volume, and adsorption enthalpy. MN270 is selected mainly due to its high surface area and narrow pores for investigation of the spillover enhancement …

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 …

Net Effects Of Batrachochytrium Dendrobatidis (Bd) And Fungicides On Anurans Across Life Stages, Jenise Brown

USF Tampa Graduate Theses and Dissertations

Amphibians are declining at alarming rates globally. Multiple factors contribute to these declines, including chemical contaminants and emergent diseases. In recent years, agrochemical use, especially fungicide applications, has increased considerably. Previous studies have demonstrated that these agrochemicals leave application sites and enter wetlands via runoff and have detrimental effects on non-target organisms. For example, exposure to contaminants can have multifarious effects on amphibians, such as reducing their ability to deal with a secondary stressor, such as disease.

A pathogen that is found concomitant with chemical contaminants in aquatic systems is Batrachochytrium dendrobatidis (Bd). Bd has decimated amphibian populations worldwide. Susceptibility …

Insight Into The Use, Perception, And Value Surrounding Domestic Water In Peru: Envisioning Demand Management In An Intermittent, Small-City, Service Context, Merril Augusta Putnam

USF Tampa Graduate Theses and Dissertations

Population growth, urbanization, degrading water quality, and climate change are making management of scarce water resources an increasingly difficult task for the domestic sector. It is recognized that in order to manage urban water resources demand management is requisite. Demand management has been experimented with in large cities of developing countries but continued focus on expanding supply overshadows its potential benefits and ultimate success. In order to manage demand, it must be measured and understood. Intermittent water services are prevalent in developing countries, but unmetered domestic water use under such conditions has not been carefully studied. This study conducted 1,149 …

Time Scale Of Groundwater Recharge: A Generalized Modeling Technique, Makhan Virdi

USF Tampa Graduate Theses and Dissertations

Estimating the quantity of water that reaches the water table following an infiltration event is vital for modeling and management of water resources. Estimating the time scale of groundwater recharge after a rainfall event is difficult because of the dependence on nonlinear soil characteristics and variability in antecedent conditions. Modeling the flow of water through the variably saturated zone is computationally intensive since it requires simulation of Richards' equation, a nonlinear partial differential equation without a closed-form analytical solution, with parametric relationships that are difficult to approximate. Hence, regional scale coupled (surface water - groundwater) hydrological models make simplistic assumptions …

Improving Implementation Of A Regional In-Line Chlorinator In Rural Panama Through Development Of A Regionally Appropriate Field Guide, Benjamin A. Yoakum

USF Tampa Graduate Theses and Dissertations

Access to safe drinking water has a direct effect on improving human health and their quality of life. One country still struggling with providing access to safe drinking water to all of its population is Panama. Panama's largest indigenous group, the Ngöbe people, is disproportionately affected by lack of access to safe drinking water. One way Panama's Ministry of Health (MINSA) is attempting to increase access to safe drinking water to the Ngöbe people is by disinfecting the water already captured by rural gravity fed water systems constructed within in the Ngöbe-Bugle reservation. This is accomplished using an in-line chlorinator …

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 …

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 …

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 …

Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer

USF Tampa Graduate Theses and Dissertations

The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource.

Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive …