Digital Commons Network^™

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 …

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. …

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. …

Development Of A Ctd System For Environmental Measurements Using Novel Pcb Mems Fabrication Techniques, Heather Allison Broadbent

USF Tampa Graduate Theses and Dissertations

The development of environmental continuous monitoring of physicochemical parameters via portable small and inexpensive instrumentation is an active field of research as it presents distinct challenges. The development of a PCB MEMS-based inexpensive CTD system intended for the measurement of environmental parameters in natural waters, is presented in this work. Novel PCB MEMS fabrication techniques have also been developed to construct the conductivity and temperature transducers. The design and fabrication processes are based on PCB MEMS technology that combines Cu-clad liquid crystal polymer (LCP) thin-film material with a direct write photolithography tool, chemical etching and metallization of layers of electroless …

The Impact Of Privatization Of Primary Care Programs In Large County Health Departments In Florida, Arlesia Lynn Brock

USF Tampa Graduate Theses and Dissertations

Since the mid-1970s, top managers, politicians, and officials in both public and private institutions have promoted contracting-out services (privatization) as a means of increasing efficiency, flexibility, and quality. The privatization trend has occurred in many public sector organizations particularly in city services and prisons. Public health services are not immune to this trend. Today many county health departments have contracted the provision of public health services like womens health, primary care, and laboratory services. However, very few studies have analyzed the impact of these privatizations on cost, access, and health outcomes. Proponents favoring the private provision of these services argue …

A Co-Orientational Analysis Of Public Involvement Perceptions In The Transportation Process: A Case Study, Kristen E. Carson

USF Tampa Graduate Theses and Dissertations

This study explored public involvement within the Florida Department of Transportation (FDOT) using the co-orientational theory. Effective public involvement gives the public opportunities to be involved early in the planning and implementation of transportation projects that directly affect or may concern them. The co-orientational model looks at what an organization (FDOT) thinks about an issue (public involvement), what the public thinks of the issue, what the organization thinks the public thinks about the issue, and what the public thinks the organization thinks about the issue.

This study investigated whether the FDOT management has an accurate understanding of the perceptions of …

Fabrication Of Palladium Nanoparticles And Nanoporous Alumina Templates, Pavani Chennapragada

USF Tampa Graduate Theses and Dissertations

Nanostructured materials have potential technological applications due to their characteristic dimensions. The material performance will depend on the atomic structure, and composition of these materials. This thesis focuses on proposing a reliable method for fabricating nanoporous alumina and palladium nanoparticles inside the templates. Palladium nanoparticles were synthesized in commercial porous alumina templates using electrodeposition. Pores within these nanoporous membranes act as templates for the synthesis of nanostructures of the desired material. Electrodeposition is achieved using a three-terminal set-up and a potentiostat. Different types of deposition techniques were investigated to improve the distribution of the deposit. The nanoparticles were characterized by …

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 …

The Design, Fabrication, And Characterization Of Polymer-Carbon Nanotube Composites, Lanetra Clayton

USF Tampa Graduate Theses and Dissertations

The design, fabrication, and characterization of polymer-carbon nanotube (CNT) composites have generated a significant amount of attention in the fields of materials science and polymer chemistry. The challenge in fabricating composites that exploit the unique properties of the CNT and the ideal processing ability and low cost of the polymer is in achieving a uniform dispersion of the filler in the polymer matrix. This body of work focuses on (1) techniques employed to disperse CNTs into a polymer matrix and (2) the effects of CNTs on the mechanical and electrical properties of the polymer.

Poly (methyl methacrylate) (PMMA), an amorphous …

Theoretical And Experimental Investigation Of Phase Behavior Of Polymeric Systems In Supercritical Carbon Dioxide And Their Modeling Using Saft, Ratka Damnjanovic

USF Tampa Graduate Theses and Dissertations

Environmentally friendly processing of materials is becoming an increasingly important consideration in a wide variety of emerging technologies. Polymer processing, in particular, has benefited tremendously in this venue from numerous advances achieved using high-pressure carbon dioxide (CO₂) as a viscosity modifier, plasticizing agent, foaming agent, and reaction medium. Polymer processing in supercritical fluids has been a major interest for a portfolio of materials processing applications including their impregnation into porous matrices. Also, SCF solvents are being examined as a media for polymerization processes, polymer purification and fractionation, and as environmentally preferable solvents for solution coatings. Pressurized CO_{2 …}

An Empirical Investigation Of The Predictors Of Self- And Other Reported Marketability: Looking Beyond Human Capital, Rachel Day

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to propose and test a comprehensive model of marketability using both individual and situational predictors. Participants in this study were members of professional associations and were recruited from internet listserves. They consisted of 485 employees and 176 co-workers. This study used a matching technique to link participant and co-worker data and was the first study to assess multiple perspectives of marketability. Results demonstrated the relationships of human capital variables, positivity traits, proactive career behaviors, the environment and industry characteristics on internal and external marketability. Interestingly, not all predictors related to both internal and external …

Formation Of Nanocoatings By Laser-Assisted Spray Pyrolysis And Laser Ablation On 2d Gold Nanotemplates, Gayan S. Dedigamuwa

USF Tampa Graduate Theses and Dissertations

This thesis describes a new Laser-Assisted Spray Pyrolysis technique developed to grow nanoparticle coatings with controllable particle sizes. In this method, droplets of a precursor formed by a nebulizer are injected into a growth chamber using SF6 carrier gas. An experimental study and a computational model to investigate the particle size dependence on various growth parameters have been carried out. The results show that heating of 1.5µm droplets of metalorganic precursor in a carrier gas using a CO2 laser resulted in the formation of TiC and Fe3O4 particles with diameters in the range of 50- 60nm. Also the results show …

The Impact Of Gender-Role Stereotypes And The Sex-Typing Of The Professor Job On Performance Evaluations In Higher Education, Jay M. Dorio

USF Tampa Graduate Theses and Dissertations

The present study examined the influences of gender-role stereotypes, gender-role congruity, and the sex-typing of the professor job on performance evaluations of university educators in actual classroom settings. Participants used the Schein Descriptive Index (Schein, 1973) to define gender-role stereotypes, characteristics of their professor/instructor, and the characteristics of an “Effective Professor.” Participants used a behavior summary scale (BSS) formatted student assessment of instruction to evaluate their professor’s/instructor’s performance after a full semester of class participation.

It was hypothesized that a pro-male bias would exist in the sex-typing of the professor job, and that combined with the gender-role stereotypes of participants …

Development And Validation Of A Systematically Designed Unit For Online Information Literacy And Its Effect On Student Performance For Internet Search Training, Emily K. Dunsker

USF Tampa Graduate Theses and Dissertations

As online learning increases and classroom use of print textbooks are gradually replaced by web-based instruction, what features of online instruction prove beneficial to student learning? The present study has three purposes; (1) To examine the effects of conversion of textbook content to web-based instruction for an extant Internet search course. The researcher examined performance differences of an online textbook to web tutorial compared to a second version that included interactive features found in classroom instruction. (2) To investigate students’ perceptions of material that afforded high levels of learner control and compared responses to a more structured instructional module. (3) …

Design, Construction And Testing Of A Wheelchair-Mounted Robotic Arm, Kevin D. Edwards

USF Tampa Graduate Theses and Dissertations

A wheelchair-mounted robotic arm (WMRA) was designed and built to meet the needs of mobility-impaired persons, and to exceed the capabilities of current devices of this type. The mechanical design incorporates DC servo drive, with all actuator hardware at each individual joint, allowing reconfigurable link lengths. It has seven principal degrees of freedom and uses a side mount on a power wheelchair. A simple, scalable control system allows coordinated Cartesian control, and offers expandability for future research, such as coordinated motion with the wheelchair itself. Design payload including gripper is 6 kg, and the total arm mass with controller is …