Arts and Humanities Commons^™

Sensitivity Analysis Of Design Parameters For Trunnion-Hub Assemblies Of Bascule Bridges Using Finite Element Methods, Jai P. Paul

USF Tampa Graduate Theses and Dissertations

Hundreds of thousands of dollars could be lost due to failures during the fabrication of Trunnion-Hub-Girder (THG) assemblies of bascule bridges. Two different procedures are currently utilized for the THG assembly. Crack formations in the hubs of various bridges during assembly led the Florida Department of Transportation (FDOT) to commission a project to investigate why the assemblies failed.

Consequently, a research contract was granted to the Mechanical Engineering department at USF in 1998 to conduct theoretical, numerical and experimental studies. It was found that the steady state stresses were well below the yield strength of the material and could not …

Voices From A Marginalized Population: Life Histories Of Individuals With Physical Impairments, James Peter Marsh

USF Tampa Graduate Theses and Dissertations

Individuals with physical impairments have been marginalized and discriminated against since the social identification of these individuals occurred as a sub-group within society. While much has been done to resolve prejudice against individuals with physical impairments, more needs to be done to decrease, or at least deter, discrimination and prejudice against individuals who have been marginalized. The purpose of this study is to give four individuals with physical impairments the opportunity to tell their stories. Through the telling of these stories, I believe others can identify with these individuals, and thereby, help decrease discrimination against individuals with physical impairments.

Life …

Developing An Anthropology Curriculum For High School: A Case Study From Durant High School, Hillsborough County, Florida, Kory Mcneil Bennett

USF Tampa Graduate Theses and Dissertations

It has become increasingly apparent that anthropology has much to offer when it comes to educating our youth. This is true for all grade levels, kindergarten through senior level studies in high school. Here, this idea will be explored further by focusing on the students of Durant High School (DHS) of Plant City, Florida.

This project was designed to explore the idea of combining widely accepted pedagogical theories (Gardner 1983, 1993, 1999; Geraci 2000; Silver, Strong and Perini 1997) with anthropological theory and methods in order to devise effective curricula for high school archaeology and other anthropology courses. More essentially, …

Organizational Citizenship Behavior: A Career Development Strategy, Martha J. Sutton

USF Tampa Graduate Theses and Dissertations

The goals of the present study were to 1.) develop a model of career related factors that could be related to organizational citizenship behaviors (OCB); and 2.) determine if the proposed relationships between the career focused variables and OCB differed across rating source. A total of 262 volunteers from a Corporation and University completed a survey in either online or by paper and pencil that included demographics and measures of: job involvement, career motivation, occupational commitment, perceptions of career plateau, career stage, and OCB. Ratings of OCB were obtained from approximately 195 participant supervisors and/or coworkers.

Correlational and multiple regression …

Effect Of Heat Treatments And Reduced Absorber Layer Thickness On Cu(In,Ga)Se2 Thin Film Solar Cells, Vinodh Chandrasekaran

USF Tampa Graduate Theses and Dissertations

Thin film solar cells with Copper Indium Gallium Diselenide (Cu(In,Ga)Se₂) absorber layers is one of the most promising candidates to emerge as an efficient solar cell technology in the near future. CIGS cells with efficiencies of 19.2 % have already been reported [1]. In this study, CIGS absorber layers are fabricated by a two-stage all-solidstate manufacture-friendly process. In the first stage, designated as precursor deposition, Copper and Gallium are sequentially deposited followed by co-deposition of Indium and Selenium. In the second stage, designated as selenization, the substrate is annealed at high temperatures in a selenium environment during which …

Stability Studies Of Cdte/Cds Thin Film Solar Cells, Bhaskar Reddy Tetali

USF Tampa Graduate Theses and Dissertations

CdTe/CdS solar cells have shown great potential for terrestrial solar power applications. To be commercially viable they need to operate efficiently for about 30 years. CdS/CdTe solar cells fabricated at USF have shown record efficiencies upto 16.5% [46]. This research involves the study of thermal stress (TS) and light soaking (LS) on the stability of high efficiency (>10%) solar cells. The change in key electrical parameters V_oc, FF, J_sc, A and J_o are quantified for more than 2000 hours of stressing.

The device degradation was found to increase with stress temperature for TS. Below …

Process Monitoring And Feedback Control Using Multiresolution Analysis And Machine Learning, Rajesh Ganesan

USF Tampa Graduate Theses and Dissertations

Online process monitoring and feedback control are two widely researched aspects that can impact the performance of a myriad of process applications. Semiconductor manufacturing is one such application that due to the ever increasing demands placed on its quality and speed holds tremendous potentials for further research and development in the areas of monitoring and control. One of the key areas of semiconductor manufacturing that has received significant attention among researchers and practitioners in recent years is the online sensor based monitoring and feedback control of its nanoscale wafer fabrication process.

Monitoring and feedback control strategies of nanomanufacturing processes often …

Design And Optimization Of Broadband Planar Baluns And Dipole Antennas, Sergio E. Melais

USF Tampa Graduate Theses and Dissertations

Due to the rapid growth in the filed of RF and Microwaves circuits, the demand for smaller, faster, and more precise devices has increased. In this thesis, a compact shielded balun, a diode detector, and a broadband sleeve dipole are modeled and implemented resulting in optimal devices presenting accurate operation.

The balun circuit is designed to meet the need for a miniaturized device with broadband application. A balun is a transformer used to connect unbalanced to balanced circuitry, for example, the unbalanced connection from a power splitter (coax) to the balanced input (two-wire) of a dipole. The main objective for …

Stress Diagnostics And Crack Detection In Full-Size Silicon Wafers Using Resonance Ultrasonic Vibrations, Anton Byelyayev

USF Tampa Graduate Theses and Dissertations

Non-destructive monitoring of residual elastic stress in silicon wafers is a matter of strong concern for modern photovoltaic industry. The excess stress can generate cracks within the crystalline structure, which further may lead to wafer breakage. Cracks diagnostics and reduction in multicrystalline silicon, for example, are ones of the most important issues in photovoltaics now. The industry is intent to improve the yield of solar cells fabrication. There is a number of techniques to measure residual stress in semiconductor materials today. They include Raman spectroscopy, X-ray diffraction and infrared polariscopy. None of these methods are applicable for in-line diagnostics of …

Assessing The Issue Of Arbitrariness In Capital Sentencing In North Carolina: Are The Effects Of Legally Relevant Variables Racially Invariant?, Judith Kavanaugh Earl

USF Tampa Graduate Theses and Dissertations

This study analyzed case and sentencing data from 632 capital cases involving Black and White defendants and victims, processed in North Carolina from May 1990 through December 2002. Logistic regression analysis of all cases and race-specific data allowed assessment of the variable effects of jury acceptance of statutory aggravating and mitigating factors on capital sentencing outcomes (death versus life). The purpose was to evaluate the role race plays in shaping jury use of legally defined factors in capital sentencing. Significant variance in the effect of jury acceptance of aggravators was observed between Black and White defendants. Black defendants pay a …

The Impact Of Victim-Offender Familial Relationships On Capital Sentencing Outcomes, Katharine D. Evans

USF Tampa Graduate Theses and Dissertations

This study is an investigation of whether familial relationships among offenders and their victims affect capital sentencing. Using a sample of capital cases from North Carolina restricted to familial homicides, logistic regression models are used while controlling for legal and extra-legal factors that influence decision outcomes. Such models of capital sentencing are developed to (1) determine whether familial-victim cases have unique correlates; and (2) whether there are variations in the effects of these correlates across gender. Contradictory to these hypotheses, results suggest that acquaintance and stranger relationships are less likely to receive a capital outcome when compared to familial relationships. …

Self-Control, Gang Membership, And Victimization: An Integrated Approach To The Risk Factors Of Violent Victimization, Kristina Childs

USF Tampa Graduate Theses and Dissertations

This study integrates one of the most empirically tested individual characteristics (self-control) with situational factors (risky lifestyle) in an attempt to explain the risks involved in violent victimization. Data came from a diverse sample of 3,907 middle school students who participated in the G.R.E.A.T. program during the 1993-1994 school year. Gang membership is used as a proxy variable to measure risky lifestyle. It is hypothesized that 1) gang membership will mediate the effect of self-control on violent victimization and 2) self-control and gang membership will interact to amplify the risk of violent victimization.

Logistic regression was used to analyze the …

High Resistivity Zinc Stannate As A Buffer Layer In Cds/Cdte Solar Cells, Sudhakar R. Gayam

USF Tampa Graduate Theses and Dissertations

The electrical conductivity of transparent conducting oxides is well exploited in front surface electrodes for solar cells where high transmission is also important. Fluorine doped tin oxide (SnO₂: F) is the most popular choice of front contacts for CdTe solar cells. In this thesis, Cd₂SnO₄ and Zn₂SnO₄ thin films are investigated focusing on their electrical and optical properties and used them in solar cells. Processing for these materials is optimized for optimum solar cell performance.

Cd₂SnO₄ thin films are deposited by co-sputtering of CdO and SnO₂ targets in …

Understanding Roi Metrics For Software Test Automation, Naveen Jayachandran

USF Tampa Graduate Theses and Dissertations

Software test automation is widely accepted as an efficient software testing technique. However, automation has failed to deliver the expected productivity more often than not. The goal of this research was to find out the reason for these failures by collecting and understanding the metrics that affect software test automation and provide recommendations on how to successfully adopt automation with a positive return on investment (ROI). The metrics of concern were schedule, cost and effectiveness. The research employed an experimental study where subjects worked on individual manual and automated testing projects. The data collected were cross verified and supplemented with …

Stability Studies Of Cdte Solar Cells Fabricated With Varying Amounts Of Cu In The Back Contact, Swetha Erra

USF Tampa Graduate Theses and Dissertations

Solar energy is one of the abundant, non-polluting renewable energy options in our planet. During the last three decades considerable progress has been achieved in developing technologies to produce electricity from solar radiation, but producing electricity with low cost and low pollution is of concern. The CdTe solar cells are the leading source for the production of cost effective solar cells. The main issue of concern in these CdTe solar cells is degradation observed when stressed at elevated temperatures. The degradation in CdTe solar cells can be attributed to the back contact, which often contains Cu to improve the electronic …

Hybrid Model For Characterization Of Submicron Particles Using Multiwavelength Spectroscopy, Alicia Garcia-Lopez

USF Tampa Graduate Theses and Dissertations

The area of particle characterization is expansive; it contains many technologies and methods of analysis. Light spectroscopy techniques yield information on the joint property distribution of particles, comprising the chemical composition, size, shape, and orientation of the particles. The objective of this dissertation is to develop a hybrid scattering-absorption model incorporating Mie and Rayleigh-Debye-Gans theory to characterize submicron particles in suspension with multiwavelength spectroscopy.

Rayleigh-Debye-Gans theory (RDG) was chosen as a model to relate the particles joint property distribution to the light scattering and absorption phenomena for submicron particles. A correction model to instrument parameters of relevance was implemented to …

Multichannel Functional Data Decomposition And Monitoring, Hani Kababji

USF Tampa Graduate Theses and Dissertations

With current advances in sensors and information technology, online measurements of process variables become increasingly accessible for process control and monitoring. Such measurements may take the shape of curves rather than scalar values. The term Multichannel Functional Data (MFD) is used to represent the observations of multiple process variables in the shape of curves. Generally MFD contains rich information about processes. The challenge of process control in MFD is that Statistical Process Control (SPC) is not directly applicable. Furthermore, there is no systematic approach to interpret the complex variation in MFD. In this research, our objective is to develop an …

Characterization Of L-Cysteine Thin Films Via Photoemission Spectroscopy, Roy Gargagliano

USF Tampa Graduate Theses and Dissertations

Using photoemission spectroscopy (PES) the interface between the amino acid Lcysteine and a Au substrate was characterized to determine its electronic and chemical structure. L-cysteine was deposited on a Au substrate in several experiments via dipping into solution or via evaporation. The depositions were performed in several steps. Between deposition steps x-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were taken. XPS was used to characterize the chemical interaction at the interface while UPS was used to determine the orbital line-up at the interface and the highest molecular orbital (HOMO) structure of L-cysteine. The results indicate the formation …

Performance Oriented Scheduling With Power Constraints, Brian C. Hayes

USF Tampa Graduate Theses and Dissertations

Current technology trends continue to increase the power density of modern processors at an exponential rate. The increasing transistor density has significantly impacted cooling and power requirements and if left unchecked, the power barrier will adversely affect performance gains in the near future. In this work, we investigate the problem of instruction reordering for improving both performance and power requirements. Recently, a new scheduling technique, called Forced Directed Instruction Scheduling, or FDIS, has been proposed in the literature for use in high level synthesis as well as instruction reordering [15, 16, 6]. This thesis extends the FDIS algorithm by adding …

Rational Fraction Approximations For Passive Network Functions, William Joel Dietmar Johnson

USF Tampa Graduate Theses and Dissertations

In electrical engineering, the designer is often presented with the problem of synthesizing a circuit for which the mathematical specifications are unsuitable for physical realization. Hence, the engineer must approximate as well as possible the prescribed network function by another function which is realizable. This paper describes a new approximation method for solving the problem of realizing passive network transfer functions, where the realization is carried out through the use of passive, reciprocal, lumped, linear, and time-invariant elements.

Optical Response Of Polycrystalline Mercuric Iodide Photoconductive Detectors, Prashant Chegoor

USF Tampa Graduate Theses and Dissertations

Mercuric Iodide in its tetragonal form has received a lot of attention for many years as a prospective room temperature X-ray and y-ray detector. Its basic properties are well suited for this purpose. Its wide band gap of 2.1eV contributes to a high dark resistivity of 10¹²ohm-cm or higher. A high atomic number of its constituent atoms (Hg-80, I -53) and a density of 6.3g/cm³ result in its efficient interaction with incident X-ray or y-ray radiation. Single crystalline mercuric iodide has been thoroughly studied and successfully utilized in commercial radiation detectors. But with the urgent need for …

Leakage Power Driven Behavioral Synthesis Of Pipelined Asics, Ranganath Gopalan

USF Tampa Graduate Theses and Dissertations

Traditional approaches for power optimization during high level synthesis, have targetted single-cycle designs where only one input is being processed by the datapath at any given time. Throughput of large single-cycle designs can be improved by means of pipelining. In this work, we present a framework for the high-level synthesis of pipelined datapaths with low leakage power dissipation. We explore the effect of pipelining on the leakage power dissipation of data-flow intensive designs. An algorithm for minimization of leakage power during behavioral pipelining is presented. The transistor level leakage reduction technique employed here is based on Multi-Threshold CMOS (MTCMOS) technology. …

Flood Forecasting Using Time Series Data Mining, Chaitanya Damle

USF Tampa Graduate Theses and Dissertations

Earthquakes, floods, rainfall represent a class of nonlinear systems termed chaotic, in which the relationships between variables in a system are dynamic and disproportionate, however completely deterministic. Classical linear time series models have proved inadequate in analysis and prediction of complex geophysical phenomena. Nonlinear approaches such as Artificial Neural Networks, Hidden Markov Models and Nonlinear Prediction are useful in forecasting of daily discharge values in a river. The focus of these methods is on forecasting magnitudes of future discharge values and not the prediction of floods. Chaos theory provides a structured explanation for irregular behavior and anomalies in systems that …

Process Development And Characterization Of Sol-Gel Lead Zirconate Titanate Films For Fabrication Of Flexural Plate Wave Devices, Praveen Kumar Sekhar

USF Tampa Graduate Theses and Dissertations

In recent years, research on development of chemical, biological and hazardous gas sensors for homeland security have attracted great deal of interest. Actuators possessing high sensitivity, easy fabrication techniques and excellent integration compatibility are in great demand. Towards this need, the development and characterization of improved solgel processing for in-house fabrication of highly sensitive and reliable Flexural Plate Wave (FPW) device was pursued

This work focuses on an experimental design approach to improve texture and morphology of PZT thin film by systematically controlling the spin, pyrolysis and anneal cycles. The process alterations resulted in an 8-fold increase in the relative …

Self-Guided Micro Vehicle: An Autonomous Vehicle With Gps Navigation And 802.11b Communications, Roberto J. Guerra

USF Tampa Graduate Theses and Dissertations

To facilitate the learning of automatic navigation systems by engineering students an easy to obtain platform is useful. The topic of this thesis is the design and implementation of a basic self-guided vehicle that can be programmed and expanded by anyone possessing basic experience with the C programming language. The Self-Guided Micro Vehicle, (SGMV), uses off-the-shelf easy to obtain parts such as a toy R/C truck and the Handyboard to maximize availability of this technology to students.

This thesis divides the SGMV design process by functionality. It starts by documenting the locomotion system, which was a modified R/C toy truck. …

Molybdenum As A Back Contact For Cucl Treated Cds/Cdte Solar Cells, Matheshkumar Jayabal

USF Tampa Graduate Theses and Dissertations

CdTe is one of the most promising absorbers for use in inexpensive semiconductor solar cells having achieved a high efficiency of 16.4% in small area cells [1]. One of the most important technological problems in obtaining high efficiencies is to have a good ohmic contact on the CdTe, which is characterized by a very high work function [2]. Cu is used as a dopant in CdTe at the contact to promote quantum mechanical tunneling [3]. But the oversupply of Cu causes the diffusion of Cu through CdTe to the underlying CdS layer resulting in the degradation of the cell performance. …

Concerted Evolution In Sm50, A Gene With Unusual Repeat Structure, Sofia Hussain

USF Tampa Graduate Theses and Dissertations

Genes present in multiple copies and genes that contain regions of repetitive sequences can undergo concerted evolution, which results in homogenization of the nucleotide sequence of the genes or repetitive regions. In regions of tandem repeats, this occurs through misalignment of repeat units followed by unequal crossover, which generates two products with differing numbers of repeat units. Gene conversion is thought to lead to one of these products becoming fixed in a species. The homogenous sequence of previously studied genes that have been thought to undergo this process has made it difficult to determine the exact models involved. Here I …

Opportunistic Maintenance Policy Of A Multi-Unit System Under Transient State, Sulabh Jain

USF Tampa Graduate Theses and Dissertations

Most modern systems are equipped with very complex, expensive, and high technology components whose maintenance costs have become an increasingly large portion of the total operating cost of these systems. Thus, the efficacy of the maintenance policy for these and related systems has become a major concern to both manufacturing and design engineers. Different kinds of maintenance strategies have been proposed to solve the problem. While some of these have proven effective, there is yet no definitive approach that has been found that support the maintainability requirements of transient systems or systems that exhibit transient behavior. Transient behavior is the …

A Generalized Decision Model For Naval Weapon Procurement: Multi-Attribute Decision Making, Jin O. Chang

USF Tampa Graduate Theses and Dissertations

For any given reason, every year many countries spend a lot of money purchasing at least one weapon. Due to the secret character of the military, the decision process for specific weapon procurement is shrouded. Moreover, there are several funds loss cases due to mistakes in weapon contractions. Weapon procurement requires very large amounts of money which comes from tax payers. Therefore, an effort to reduce a possible monetary loss is needed.

A decision process based on an analytic model can present a better chance to decision makers for better weapon decisions. In general, weapon procurement decision is a multi …

Development Of Interactive Web-Based Tutorials For Chemical Engineering Undergraduates, Stefan Cular

USF Tampa Graduate Theses and Dissertations

This thesis presents the design, creation, and testing of a web-based tool for generating interactive web-based problem set assignments. In prior research (Stetka, 2001) it was shown that students enjoyed interactive problems. In this research, multiple programming languages were used to provide a web-based, fully interactive, problem solving environment for the students. Sample problem sets were written by the author and a few chemical engineering students.

These web pages were then used as a basis to test the effectiveness of the webbased interactive problem sets for two engineering courses. Initial findings are presented illustrating the student’s results along with results …