Digital Commons Network^™

Re-Establishing Place Through Knowledge: A Facility For Earth Construction Education In Pisco, Peru, Hannah Jo Sebastian

USF Tampa Graduate Theses and Dissertations

Human vulnerability can be characterized as people living with uncertain livelihood options, precariously settled in structurally unsafe buildings. A striking aspect of this vulnerability is the large number of people living in earthen structures within seismically active zones. This reality is exemplified by the earthquake which occurred this past summer around Pisco, Peru. The earthquake caused enormous damage to more than 80% of the adobe buildings. Although confined masonry is the preferred construction technique for families who can afford it, adobe is still the only economically viable alternative for most.

Presently reconstruction efforts are focused on encouraging residents to build …

Sedimentation Of Organic - Inorganic Composites By Optical Turbidity, Reshma K. Harrinauth

USF Tampa Graduate Theses and Dissertations

Sedimentation is one of many characterization tools used to test materials in nanotechnology. Characterization of settling behavior is complex as there are many variables which can affect sedimentation. In our research, we focused on sedimentation in colloidal systems with the aid of an optical turbidometer. Nanoparticles of CeO₂ (Ceria Oxide) and TiO₂ (Titanium Dioxide) are embedded onto a polymeric matrix of a thermally responsive microgel of poly(N-isopropylacrylamide) (PNIPAM) and interpenetrating chains of poly(acrylic acid) to create novel composites. The composites are loaded with the inorganic oxide nanoparticles at different weight percent from a low value of 10 weight …

Fault-Tolerant Adaptive Model Predictive Control Using Joint Kalman Filter For Small-Scale Helicopter, Carlos L. Castillo

USF Tampa Graduate Theses and Dissertations

A novel application is presented for a fault-tolerant adaptive model predictive control system for small-scale helicopters. The use of a joint Extended Kalman Filter, (EKF), for the estimation of the states and parameters of the UAV, provided the advantage of implementation simplicity and accuracy. A linear model of a small-scale helicopter was utilized for testing the proposed control system. The results, obtained through the simulation of different fault scenarios, demonstrated that the proposed scheme was able to handle different types of actuator and system faults effectively. The types of faults considered were represented in the parameters of the mathematical representation …

Motion-Logger: An Attitude And Motion Sensing System, Andres Felipe Marquez

USF Tampa Graduate Theses and Dissertations

This thesis proposes a motion sensing system for wheelchairs with the main objective of determining tips, falls and risky situations. The system relies on measurements from an Inertial Measurement Unit, (IMU), consisting of a 3-axis accelerometer and a 2-axis gyroscope as the source of information. The IMU was embedded in a portable device, the "Motion Logger", which collects motion data in a Secure Digital memory card after running a real time preprocessing algorithm. The algorithm was designed to reduce energy consumption and memory usage. Actual signal analysis and attitude estimation is carried out offline.

The motion sensing system was developed …

Copper Doped Window Layer For Cdse Solar Cells, Sheetal Kumar Chanda

USF Tampa Graduate Theses and Dissertations

CdSe solar cells with ZnTe as the window layer deposited by CSS process have shown V_oc's around 630mV. However the currents were very low and also the voltages were not meeting the desired objectives. To improve the performance the contact energy at the ZnTe/Cu interface should be minimized by doping the window layer.

Thermal evaporation was used to deposit ZnTe to have more control over the composition of the film. Initial experiments were done by depositing Cu doped ZnTe films on plain glass by co-evaporating both ZnTe and Cu. The conductivity was in the order of 10e3 which …

Socializing Housing Phased Early Response To Impromptu Migrant Encampments In Lima, Peru, Raul E. Mayta

USF Tampa Graduate Theses and Dissertations

Every year hundreds of people migrate from the highlands of Peru to the coastal capital of Lima searching for economic and social stability. These groups of people have similar characteristics that keep them together they come from the same city, are members of the same family, have the same religion, have similar goals, and so on. Once in Lima they take possession of the only free areas left in the city: the mountains. Due to a lack of economic resources, poor urban planning and unsuitable site conditions the settlements grow for years in a disorderly, unsafe and unsanitary way, creating …

Discrete Linear Constrained Multivariate Optimization For Power Sources Of Mobile Systems, Stelios G. Ioannou

USF Tampa Graduate Theses and Dissertations

Unmanned ground and aerial vehicles (UGVs and UAVs) have strict payload limitations, limited free space affecting on board power availability resulting in limited endurance and operational range. This limitation is exacerbated by the addition of sensors, actuators and other related equipment needed to accomplish mission objectives in diverse applications.

Two energy sources are mainly available for mobile applications; batteries and fuel cells. Batteries are a relatively cheap, tested technology with good performance under varying loads. On the other hand, fuel cells offer fast and easy refueling solutions. Furthermore, preliminary studies have shown that a hybrid system can combine the advantages …

The Virtual Landscape Of Geological Information Topics, Methods, And Rhetoric In Modern Geology, Sarah Elizabeth Fratesi

USF Tampa Graduate Theses and Dissertations

Geology is undergoing changes that could influence its knowledge claims, reportedly becoming more laboratory-based, technology-driven, quantitative, and physics- and chemistry-rich over time. This dissertation uses techniques from information science and linguistics to examine the geologic literature of 1945-2005. It consists of two studies: an examination of the geological literature as an expanding network of related subdisciplines, and an investigation of the linguistic and graphical argumentation strategies within geological journal articles.

The first investigation is a large-scale study of topics within articles from 67 geologic journals. Clustering of subdiscipline journals based on titles and keywords reveals six major areas of geology: …

Analysis Of Water Seepage Through Earthen Structures Using The Particulate Approach, Kalyani Jeyisanker

USF Tampa Graduate Theses and Dissertations

A particulate model is developed to analyze the effects of steady state and transient seepage of water through a randomly-packed coarse-grained soil as an improvement to conventional seepage analysis based on continuum models. In the new model the soil skeleton and pore water are volumetrically coupled. In the first phase of the study, the concept of relative density has been used to define different compaction levels of the soil layers of a completely saturated pavement filter system and observe the seepage response to compaction. First, Monte-Carlo simulation is used to randomly pack discrete spherical particles from a specified Particle Size …

Laser Remote Sensing Of Trace Chemical Species Using 10.6 Μm Co2 Laser Enhanced Breakdown Spectroscopy And Differential Absorption Lidar., Avishekh Pal

USF Tampa Graduate Theses and Dissertations

Several different laser remote sensing techniques related to the detection of trace chemical species were studied. In particular, a Differential-Absorption lidar (DIAL), a Laser-Induced-Breakdown Spectroscopy (LIBS) lidar, and a Raman lidar were studied. Several of the laser spectroscopic techniques that were used were common throughout these different studies. More precisely, 10.6 μm CO₂ laser related spectroscopy was common for the DIAL and LIBS studies, and 266 nm Nd:YAG laser related spectroscopy was used for the LIBS and Raman studies.

In the first system studied a tunable CO₂ DIAL system was developed for the first time to our knowledge …

High-Level Synthesis Framework For Crosstalk Minimization In Vlsi Asics, Hariharan Sankaran

USF Tampa Graduate Theses and Dissertations

Capacitive crosstalk noise can affect the delay of a switching signal or induce a glitch on a static signal causing timing violations or chip failure. Crosstalk noise depends on coupling parasitics, driver strength, signal timing characteristics, and signal transition patterns. Layout level crosstalk analysis techniques are generally pessimistic and computationally expensive for large designs due to lack of design flexibility at lower-levels of design hierarchy. The architectural decisions such as type of interconnect architecture, number of storage and execution units, network of communicating units, data bus width, etc., have a major impact on the quality of design attributes such as …

Chemical Mechanical Planarization: Study Of Conditioner Abrasives And Synthesis Of Nano-Zirconia For Potential Slurry Applications, Chhavi Manocha

USF Tampa Graduate Theses and Dissertations

Chemical Mechanical Planarization (CMP) has emerged as the central technology for polishing wafers in the semiconductor manufacturing industry to make integrated multi-level devices. As the name suggests, both chemical and mechanical processes work simultaneously to achieve local and global planarization. In spite of extensive work done to understand the various components and parameters affecting the performance of this process, many aspects of CMP remain poorly understood. Among these aspects of CMP is the role of abrasives in the processes of conditioning and polishing. These abrasives are present in the chemical slurry between the wafer and the pad for polishing and …

Developments Toward A Micro Bistable Aerial Platform: Analysis Of The Quadrantal Bistable Mechanism, Aaron A. Muñoz

USF Tampa Graduate Theses and Dissertations

The Bistable Aerial Platform (BAP) has been developed in order to further enlarge the repertoire of devices available at the microscale. This novel device functions as a switch in that its platform can lock in two positions, up or down. Herein, it will be examined and explained, but a true understanding of its workings requires a better understanding of its compliant constituent parts. The Helico-Kinematic Platform (HKP), which serves as an actuator for the BAP, is currently under investigation by another researcher and will be merely touched upon here. The focus, therefore, will rest on the analysis of the Quadrantal …

Reconstructions: The Contemporary Southern Landscape By Its Photographers, Natalie Kersey Gillis

USF Tampa Graduate Theses and Dissertations

The purpose of this thesis is to examine the work of landscape photographers living and working in the Southern region of the United States and to explore what their images visually communicate about their relationship to the Southern land and its distinctive history. This objective is accomplished through an analysis of the work of three contemporary landscape photographers who reside in the South, and work primarily within their local hometowns.

This thesis examines the work of photographers William Christenberry, Sally Mann, and John McWilliams. Each is a photographer who is native to the American South and has used his or …

Sequential Quantum-Dot Cellular Automata Design And Analysis Using Dynamic Bayesian Networks, Praveen Venkataramani

USF Tampa Graduate Theses and Dissertations

The increasing need for low power and stunningly fast devices in Complementary Metal Oxide Semiconductor Very large Scale Integration (CMOS VLSI) circuits, directs the stream towards scaling of the same. However scaling at sub-micro level and nano level pose quantum mechanical effects and thereby limits further scaling of CMOS circuits. Researchers look into new aspects in nano regime that could effectively resolve this quandary. One such technology that looks promising at nano-level is the quantum dot cellular automata (QCA). The basic operation of QCA is based on transfer of charge rather than the electrons itself. The wave nature of these …

Thin Film Metal-Insulator-Metal Tunnel Junctions For Millimeter Wave Detection, Subramanian Krishnan

USF Tampa Graduate Theses and Dissertations

Millimeter wave imaging systems are the next generation imaging systems being developed for security and surveillance purposes. In this work, thin film metal-insulator-metal (MIM) tunnel junction based detector using Ni-NiO-Cr has been developed for the first time for millimeter wave detection operating at 94 GHz. Extensive process development has been carried out to fabricate the MIM junctions. Arrays of MIM junctions with 1 µm² contact area and ultra-thin insulator layer of ~3 nanometer have been developed using e-beam lithography and reactive sputtering, respectively. MIM diodes were also fabricated in a bulk-micromachined diaphragm configuration to minimize surface wave loss.

DC and …

Resting Oxygen Consumption Rates In Divers Using Diver Propulsion Devices, Adam J. Smith

USF Tampa Graduate Theses and Dissertations

The Marine Corps Systems Command documented mission requirements that cannot be met by current rebreathers. They need to extend dive times without compromising the stealth and compact design of existing devices. This can be accomplished by reducing the fresh gas flow rate. The current flow rate is adequate to support a diver in heavy work. However, the diver will be utilizing a Diver Propulsion Device (DPD) during a large portion of the mission in question. The assumption, then, is that this portion of the mission will not require "hard work". Thus, a new fresh gas flow rate can be established …

Nanomanufacturing Of Silica Nanowires: Synthesis, Characterization And Applications, Praveen Kumar Sekhar

USF Tampa Graduate Theses and Dissertations

In this research, selective and bottom-up manufacturing of silica nanowires on silicon (Si) and its applications has been investigated. Localized synthesis of these nanowires on Si was achieved by metal thin film catalysis and metal ion implantation based seeding approach. The growth mechanism of the nanowires followed a vapor-liquid-solid (VLS) mechanism. Mass manufacturing aspects such as growth rate, re-usability of the substrate and experimental growth model were also investigated. Further, silica nanowires were explored as surface enhanced Raman (SER) substrate and immunoassay templates towards optical and electrochemical detection of cancer biomarkers respectively. Investigating their use in photonic applications, optically active …

Compliant Prosthetic Knee Extension Aid: A Finite Elements Analysis Investigation Of Proprioceptive Feedback During The Swing Phase Of Ambulation, Adam Daniel Roetter

USF Tampa Graduate Theses and Dissertations

Compliant mechanisms offer several design advantages which may be exploited in prosthetic joint research and development: they are light-weight, have low cost, are easy to manufacture, have high-reliability, and have the ability to be designed for displacement loads. Designing a mechanism to perform optimally under displacement rather than force loading allows underlying characteristics of the swing phase of gait, such as the maximum heel rise and terminal swing to be developed into a prosthetic knee joint. The objective of this thesis was to develop a mechanical add-on compliant link to an existing prosthetic knee which would perform to optimal standards …

Investigation And Evaluation Of A Bi-Polar Membrane Based Seawater Concentration Cell And Its Suitability As A Low Power Energy Source For Energy Harvesting/Mems Devices, Clifford Ronald Merz

USF Tampa Graduate Theses and Dissertations

It has long been known from Thermodynamics and written in technical literature that, in principal, instant energy can be made available when dilute and concentrated solutions are mixed. For example, a river flowing into the sea carries with it a physical-chemical potential energy in its low salt content, some of which should be recoverable. As also known, a naturally occurring, diffusion-driven, spontaneous transport of ions occurs throughout a solution matrix, thru barrier interfaces, or thru ion-selective membranes from the side containing the salts of higher concentration to the compartments containing the more dilute solution to effect the equalization of concentration …

Evaluation Of The Public Health Risks Associated With Former Manufactured Gas Plants, Robin Brewer Dehate

USF Tampa Graduate Theses and Dissertations

Regulatory agencies have recently focused on assessing the potential for soil vapor intrusion (SVI) and risk posed to occupants of residential and commercial properties overlying and surrounding former Manufactured Gas Plants (MGPs). This study evaluated the potential for SVI at 10 commercial buildings and 26 single family and multi-family residential properties overlying and/or adjacent to three former MGPs. The potential for SVI exposure was categorized into three groupings according to thickness of the vadose zones: no vadose zone; 0 - 6 feet thick, and 6 to 25 feet thick. Indoor and outdoor air and soil vapor samples were collected and …

Theoretical Modeling Of Cortisol Sensor, Milorad Gordic

USF Tampa Graduate Theses and Dissertations

This thesis describes the theoretical modeling of a response of an electrochemical BioMEMS sensor for detecting small amounts of cortisol hormone. The electrochemical sensor utilizes a catalyst enzyme (3a-HSD) to convert cortisone to cortisol and the Square Wave Voltammetry (SWV) as a preferred method to measure the forward and reverse current of the system. The parameters and equations necessary to estimate the Square Wave Voltammetry (SWV) theoretical response are determined and outlined. The response is modeled and the results are compared to the experimental data. Further, the design of the sensor is analyzed and suggestions are made on how to …

Modeling And Growth Of The 3c-Sic Heteroepitaxial System Via Chloride Chemistry, Meralys Reyes-Natal

USF Tampa Graduate Theses and Dissertations

This dissertation study describes the development of novel heteroepitaxial growth of 3C-SiC layers by chemical vapor deposition (CVD). It was hypothesized that chloride addition to the "traditional" propane-silane-hydrogen precursors system will enhance the deposition growth rate and improve the material quality via reduced defect density. Thermodynamic equilibrium calculations were performed to obtain a criterion for which chloride specie to select for experimentation. This included the chlorocarbons, chlorosilanes, and hydrogen chloride (HCl) chloride containing groups. This study revealed no difference in the most dominant species present in the equilibrium composition mixture between the groups considered. Therefore, HCl was the chloride specie …

Temperature And Interconnect Aware Unified Physical And High Level Synthesis, Vyas Krishnan

USF Tampa Graduate Theses and Dissertations

Aggressive scaling of nanoscale CMOS integrated circuits has created significant design challenges arising from increasing power densities, thermal concerns, and rising wire delays. The main contribution of this dissertation is the development of unified physical and high-level synthesis techniques for the design of ASICs with optimal chip temperatures and interconnect delays.

Thermal issues are becoming a serious problem in high-performance VLSI circuits, adversely impacting performance, reliability, power consumption, and cooling costs. To address this, we present a temperature-aware behavioral synthesis (TABS) framework that combines power minimization with temperature-aware task scheduling, resource binding, and floorplanning. Compared to conventional low-power synthesis methods, …

Development Of A Software-Defined Integrated Circuit Test System Using A System Engineering Approach On A Pxi Platform, Alfonso S. Flores

USF Tampa Graduate Theses and Dissertations

There are various types of test performed on Integrated Circuits, (IC), for detecting and locating defects and faults during failure analysis. Functional, logic, parametric and I_DDQ tests are among the most common. Functional IC tests are designed to verify whether the IC performs its intended function. Logic tests verify the logic operation of gates and registers. AC and DC parametric tests are used to measure time, voltage and current-varying parameters associated with the operational limits of the IC. Test parameters in parametric testing include, among others, propagation delay, operating current and signals rise and fall time.

Currently, almost all …

Seepage Rates In Closed Basins, Volha Martysevich

USF Tampa Graduate Theses and Dissertations

Seepage is an important component of the water budget in closed basins that do not have surface water drainage features. In the shallow water table environment of Florida, internal drainage of soil controls flooding. With the recent rapid population growth and urban development in the state, a simple, field-based method is needed to estimate seepage rates. In this study five locations in Hillsborough County, Florida, were instrumented with wells with pressure transducers measuring water level fluctuations at 1 minute resolution. For closed basins with lakes, evaporation (E) rates were determined using data from a weather station and Penman-Monteith FAO56 method, …

Formal Reasoning And Spatial Ability: A Step Towards "Science For All", Bo Jiang

USF Tampa Graduate Theses and Dissertations

This work conducts an evaluation of a non-majors science curriculum named Molecules of Life (MOL) that aims to provide effective science education to undergraduate students who are not majoring in scientific disciplines.

As part of the process of developing an assessment plan for MOL, three related studies were undertaken in order to help us choose assessment instruments for MOL. The first study examined the validity of student evaluations of teaching. The second study investigated the Test of Logical Thinking (TOLT) and Group Assessment of Logical Thinking (GALT), two widely-used instruments for measuring formal reasoning ability. GALT is very similar to …

Genetic Algorithm Based Design And Optimization Of Vlsi Asics And Reconfigurable Hardware, Pradeep Ruben Fernando

USF Tampa Graduate Theses and Dissertations

Rapid advances in integration technology have tremendously increased the design complexity of very large scale integrated (VLSI) circuits, necessitating robust optimization techniques in many stages of VLSI design. A genetic algorithm (GA) is a stochastic optimization technique that uses principles derived from the evolutionary process in nature. In this work, genetic algorithms are used to alleviate the hardware design process of VLSI application specific integrated circuits (ASICs) and reconfigurable hardware.

VLSI ASIC design suffers from high design complexity and a large number of optimization objectives requiring hierarchical design approaches and multi-objective optimization techniques. The floorplanning stage of the design cycle …

The Social Context Of Cervical Cancer Knowledge And Prevention Among Haitian Immigrant Women, Janelle Marie Menard

USF Tampa Graduate Theses and Dissertations

Cervical cancer is the primary cause of cancer deaths among Haitian women; however, the social context of cervical cancer among Haitian immigrant women has not been systematically examined. The ways in which women assign meaning to this disease, understand its causality and situate it within the broader context of gynecological health are poorly understood. Further, Haitian immigrant women's perceptions of disease risk, including knowledge and understanding about Human Papillomavirus (HPV), the primary etiologic factor in cervical cancer, have not been explored. Few studies have assessed health behaviors, including culturally mediated feminine hygiene practices, among Haitian immigrant women, which may negatively …

Kernel Density Estimation Of Reliability With Applications To Extreme Value Distribution, Branko Miladinovic

USF Tampa Graduate Theses and Dissertations

In the present study, we investigate kernel density estimation (KDE) and its application to the Gumbel probability distribution. We introduce the basic concepts of reliability analysis and estimation in ordinary and Bayesian settings. The robustness of top three kernels used in KDE with respect to three different optimal bandwidths is presented. The parametric, Bayesian, and empirical Bayes estimates of the reliability, failure rate, and cumulative failure rate functions under the Gumbel failure model are derived and compared with the kernel density estimates. We also introduce the concept of target time subject to obtaining a specified reliability. A comparison of the …