Engineering Commons^™

Contrast Adaptation In The Lateral Eye Of Limulus Polyphemus, Tchoudomira Valtcheva

USF Tampa Graduate Theses and Dissertations

Luminance and contrast adaptation are neuronal mechanisms that the retina applies for continuous adjustment to light sensitivity though a collection of cellular and synaptic mechanisms distributed across the retinal network, thus accommodating the wide input range of the visual system within the constricted output range of retinal ganglion cells. Luminance mean adaptation has been demonstrated in the output neurons of the invertebrate eye (eccentric cells), and the aim of the study was to investigate whether the homology in visual processing extends to luminance variance (contrast) adaptation as well. The spike trains of individual eccentric cells were recorded from live horseshoe …

Skeletal Muscle Contraction Simulation: A Comparison In Modeling, Jonathan M. Ford

USF Tampa Graduate Theses and Dissertations

Computer generated three-dimensional (3-D) models are being used at increasing rates in the fields of entertainment, education, research, and engineering. One of the aspects of interest includes the behavior and function of the musculoskeletal system. One such tool used by engineers is the finite element method (FEM) to simulate the physics behind muscle mechanics. There are several ways to represent 3-D muscle geometry, namely a bulk, a central line of action and a spline model. The purpose of this study is to exmine how these three representations affect the overall outcome of muscle movement. This is examined in a series …

Theory, Synthesis, And Application Of Adiabatic And Reversible Logic Circuits For Security Applications, Matthew Arthur Morrison

USF Tampa Graduate Theses and Dissertations

Programmable reversible logic is emerging as a prospective logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on circuit heat generation. Adiabatic logic is a design methodology for reversible logic in CMOS where the current flow through the circuit is controlled such that the energy dissipation due to switching and capacitor dissipation is minimized. Recent advances in reversible logic using and quantum computer algorithms allow for improved computer architectures. Production of cost-effective Secure Integrated Chips, such as Smart Cards, requires hardware designers to consider tradeoffs in size, security, and power consumption. In order to design …

Future Engineering Professors' Conceptions Of Learning And Teaching Engineering, Ana Teresa Torres Ayala

USF Tampa Graduate Theses and Dissertations

Conceptions of learning and teaching shape teaching practices and are, therefore, important to understanding how engineering professors learn to teach. There is abundant research about professors' conceptions of teaching; however, research on the conceptions of teaching of doctoral students, the future professors, is scarce. Furthermore, there is a need to understand not just future engineering professors' conceptions of teaching but also their conceptions of learning. The purpose of this study was to explore qualitative variations in future engineering professors' conceptions of learning and teaching as well as understanding how they came to these conceptions.

The research questions that guided this …

Hydraulic Evaluation Of A Community Managed Wastewater Stabilization Pond System In Bolivia, Louis Lizima

USF Tampa Graduate Theses and Dissertations

This work explores the hydraulic performance of a wastewater lagoon system located in San Antonio, Bolivia. The system consists of one facultative pond and two maturation ponds in series and is managed through a locally elected water committee. A tracer study was performed on the primary facultative pond and an analysis of the solids accumulation on the bottom of the facultative lagoon was also performed. The results were used to generate residence time distribution curves and provide an estimate of mean residence time in the system. The data was used to examine hydraulic efficiency as it relates to short-circuiting and …

Environmental And Energy Saving Technologies Of Vinyl Chloride Production, Mykola Kurta

USF Tampa Graduate Theses and Dissertations

Recently, because of the increase of environmental concerns in process design, the need to enhance conversion to product and prevent generation of wasteful byproducts in the reactor network has become urgent. This prevents high cost treatment and separation costs downstream in the process. Therefore, in this thesis I focus on making production of vinyl chloride monomer (VCM) more efficient and on possible ways of industrial organochlorine waste (OCW) recycling. In particular, in the first experiment, we investigate how catalyst and its structure can affect product output.

Infrared spectroscopy and X-ray diffraction analysis were utilized to investigate the structure of the …

Location And Capacity Modeling Of Network Interchanges, Aldo D. Fabregas

USF Tampa Graduate Theses and Dissertations

Network design decisions, especially those pertaining to urban infrastructure, are made by a central authority or network leader, and taking into consideration the network users or followers. These network decision problems are formulated as non-linear bi-level programming problems. In this work, a continuous network design problem (CNDP) and discrete network design problem (DNDP) bi-level optimization programs are proposed and solved in the context of transportation planning. The solution strategy involved reformulation and linearization as a single-level program by introducing the optimality conditions of the lower level problem into the upper level problem. For the CNDP, an alternative linearization algorithm (modified …

Processing Of Advanced Two-Stage Cigs Solar Cells, Manikandan Sampathkumar

USF Tampa Graduate Theses and Dissertations

An advancement of the two stage growth recipe for the fabrication of CIGS solar cells was developed. The developed advancement was inconsistent in producing samples of similar stoichiometry. This was a huge barrier for up scaling the process as the behavior of devices would be different due to variation in stoichiometry. Samples with reproducible stoichiometry were obtained once the heating rate of elements, selenium in particular was better understood. This is mainly attributed to the exponential increase of selenium flux after its evaporation temperature. Monitoring the selenium flux was vital in getting constant selenium fluxes. Few changes to the growth …

Novel Approach Of Using Polyvinylidene Fluoride Langmuir-Schaefer Film On Graphene-Polyaniline Nanocomposite For Supercapacitor Applications, Venkata Priyanka Bolisetty

USF Tampa Graduate Theses and Dissertations

Supercapacitors are well known for their improvised power density compared to batteries. Ongoing research is mainly focused on improving the energy density of supercapacitors by using different electrode material nanocomposites. The recent research has revealed that graphene (G)-polyaniline (PANI) nanocomposite could be a promising material for supercapacitor applications. The supercapacitor is also associated with self-leakage current regardless of any electrode material. The main objectives of the project are to: (i) synthesize highly fabricate supercapacitor based of G-PANI electrode; (ii) improve the energy density of supercapacitor by applying ultrathin monolayer/monolayers film electrode surface. It is crucial to either improve or retain …

Reliability Assessment Of Ion Contamination Residues On Printed Circuit Board, Minh Tam Tran Nguyen

USF Tampa Graduate Theses and Dissertations

Ion contaminants from Printed Circuit Board (PCB) assembly processes pose a high reliability risk because they result in damaged circuits. Therefore, it is essential to understand the level of ionic species on the electronic circuitry as well as the reliability risks caused by these contaminants. There are a number of approaches available in the industry to assess the reliability risks ; for example, the water drop test (WDT) is one of the techniques used to determine the propensity of an ionic contaminant to cause electrical short failures by dendrite formation. The objective of this research is to determine the time …

Fpca Based Human-Like Trajectory Generating, Wei Dai

USF Tampa Graduate Theses and Dissertations

This thesis presents a new human-like upper limb and hand motion generating method. The work is based on Functional Principal Component Analysis and Quadratic Programming. The human-like motion generating problem is formulated in a framework of minimizing the difference of the dynamic profile of the optimal trajectory and the known types of trajectory. Statistical analysis is applied to the pre-captured human motion records to work in a low dimensional space. A novel PCA FPCA hybrid motion recognition method is proposed. This method is implemented on human grasping data to demonstrate its advantage in human motion recognition. One human grasping hierarchy …

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 …

Predicting The Clinical Outcome In Patients With Traumatic Brain Injury Using Clinical Pathway Scores, Jennifer Lorena Mendoza Alonzo

USF Tampa Graduate Theses and Dissertations

The Polytrauma/TBI Rehabilitation Center (PRC) of the Veterans Affairs Hospital (VAH) treats patients with Traumatic Brain Injury (TBI). These patients have major motor and cognitive disabilities. Most of the patients stay in the hospital for many months without major improvements. This suggests that patients, family and the VAH could benefit if healthcare provider had a way to better assess or "predict" patients' progression. The individual progress of patients over time is assessed using a pre-defined multi-component performance measure Functional Independence Measures (FIM) at admission and discharge, and a semi-quantitative documentation parameter Clinical Pathway (CP) at weekly intervals. This work uses …

Thermal Infrared Reflective Metal Oxide Sol-Gel Coatings For Carbon Fiber Reinforced Composite Structures, Brandon Demar Richard

USF Tampa Graduate Theses and Dissertations

Recent trends in composite research include the development of structural materials with multiple functionalities. In new studies, novel materials are being designed, developed, modified, and implemented into composite designs. Typically, an increase in functionality requires additional material phases within one system. The presence of excessive phases can result in deterioration of individual or overall properties. True multi-functional materials must maintain all properties at or above the minimum operating limit. In this project, samples of antimony and cobalt-doped tin oxide (ATO(Co2O3)) sol-gel solutions are used to coat carbon fibers and are heat treated at a temperature range of 200 - 500 …

User-Based Filter Utilization For Multicarrier Schemes, Zekeriyya Esat Ankarali

USF Tampa Graduate Theses and Dissertations

Multicarrier modulation is a transmission technique that is quite convenient for high data rates in wireless communication. Information symbols are partitioned and parallelly sent over multiple narrowband subchannels. Pulse shaping filters are critically important in multicarrier

modulation for determining the characteristics of signal in time and frequency domains. In this thesis, we propose a new pulse shaping approach for multicarrier schemes to increase spectral efficiency in multi-user scenarios. Conventionally, the time-frequency lattice and the prototype filter are designed considering the worst-case of time-varying multipath channel. However, this approach ignores to make use of multi-user diversity and leads to excessive spacings …

Multidimensional Signal Analysis For Wireless Communications Systems, Ali Gorcin

USF Tampa Graduate Theses and Dissertations

Wireless communications systems underwent an evolution as the voice oriented applications evolved to data and multimedia based services. Furthermore, current wireless technologies, regulations and the un-

derstanding of the technology are insufficient for the requirements of future wireless systems. Along with the rapid rise at the number of users, increasing demand for more communications capacity to deploy multimedia applications entail effective utilization of communications resources. Therefore, there is a need for effective spectrum allocation, adaptive and complex modulation, error recovery, channel estimation, diversity and code design techniques to allow high data rates while maintaining desired quality of service, and reconfigurable …

Socioeconomic Factors' And Water Source Features' Effect On Household Water Supply Choices In Uganda And The Associated Environmental Impacts, Christine M. Prouty

USF Tampa Graduate Theses and Dissertations

Over the last twenty years or more, Uganda has benefitted from significant strides in water and sanitation initiated by the United Nations' Millennium Development Goals. While the rapid progress towards development has been vastly beneficial, it is also important that it does not occur at the expense of the environment. The environmental impacts of these water sources must be evaluated and understood. However, to develop a robust understanding of the impact requires inclusion of the community members who use these sources and their perceptions of them. Consequently, the goal of this research is to investigate the interrelationships between socioeconomic factors, …

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 …

One Dimensional Stochastic Coating Growth Kinetics Of Peg 3400 Onto Ammonium Nitrate In A Fluidized Bed, Brandon Smeltzer

USF Tampa Graduate Theses and Dissertations

Fluidized beds represent a cost effective, scalable technology invaluable to the chemical processing community as part of the global scheme of particle design. However, despite wide spread use and multiple approaches (empirical and mechanistic) to modeling a fluidized bed coating process, operations must be done at different scales due to changes within the balance of phenomenological forces (e.g. gravity, buoyancy, drag, surface tension, viscosity, kinetic energy).

Ammonium nitrate is synthetic compound that has multiple applications such as fertilizer, rocket fuel, and self-cooling applications. Ammonium nitrate has five temperature dependent crystal structures that are accompanied by a change in density. The …

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 …

Development Of Novel Nano-Composite Membranes As Introduction Systems For Mass Spectrometers: Contrasting Nano-Composite Membranes And Conventional Inlet Systems, Luis Miranda

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite …

Environmental Implications Of Pavements: A Life Cycle View, Bin Yu

USF Tampa Graduate Theses and Dissertations

Environmental aspect of pavement, unlike its economic counterpart, is seldom considered in the theoretical study and field practices. As a highly energy and material intensive infrastructure, pavement has great potential to contribute to the environment protection, which, in root, depends on the in-depth understanding of the environmental impacts, holistically and specifically. A life cycle assessment (LCA) model is used to fulfill the goal.

This research firstly carried out extensive literature review of LCA studies on pavement to identify the major research gaps, including: incompleteness of the methodology, controversy of the functional unit, and unawareness of feedstock energy of asphalt, etc. …

Algorithms And Data Structures For Efficient Timing Analysis Of Asynchronous Real-Time Systems, Yingying Zhang

USF Tampa Graduate Theses and Dissertations

This thesis presents a framework to verify asynchronous real-time systems based on model checking. These systems are modeled by using a common modeling formalism named Labeled Petri-nets(LPNs).

In order to verify the real-time systems algorithmically, the zone-based timing analysis method is used for LPNs. It searches the state space with timing information (represented by zones). When there is a high degree of concurrency in the model, firing concurrent enabled transitions in different order may result in different zones, and these zones may be combined without affecting the verification result. Since the zone-based method could not deal with this problem efficiently, …

Supply Chain Optimization Of Blood Products, Serkan Gunpinar

USF Tampa Graduate Theses and Dissertations

Major challenges in the management of blood supply chain are related to the shortage and wastage of the blood products. Given the perishability characteristics of blood which can be stored up to a limited number of days, if hospitals and blood centers keep an excessive number of blood units on inventory, wastages may occur. On the other hand, if sufficient number of blood units are not stored on inventory, shortages of this resource may cause the cancellations of important activities and increase the fatality rates at hospitals. Three mathematical models have been developed with the goal to improve the efficiency …

Classification Models In Clinical Decision Making, Eleazar Gil-Herrera

USF Tampa Graduate Theses and Dissertations

In this dissertation, we present a collection of manuscripts describing the development of prognostic models designed to assist clinical decision making. This work is motivated by limitations of commonly used techniques to produce accessible prognostic models with easily interpretable and clinically credible results. Such limitations hinder prognostic model widespread utilization in medical practice.

Our methodology is based on Rough Set Theory (RST) as a mathematical tool for clinical data anal- ysis. We focus on developing rule-based prognostic models for end-of life care decision making in an effort to improve the hospice referral process. The development of the prognostic models is …

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 …

Towards Rans Parameterization Of Vertical Mixing By Langmuir Turbulence In Shallow Coastal Shelves, Nityanand Sinha

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the upper ocean is generated by the interaction between the wind-driven shear current and the Stokes drift velocity induced by surface gravity waves. In homogenous (neutrally stratified) shallow water, the largest scales of Langmuir turbulence are characterized by full-depth Langmuir circulation (LC). LC consists of parallel counter-rotating vortices aligned roughly in the direction of the wind. In shallow coastal shelves, LC has been observed engulfing the entire water column, interacting with the boundary layer and serving as an important mechanism for sediment re-suspension.

In this research, large-eddy simulations (LES) of Langmuir turbulence with full-depth LC in a …

A Biocompatible Sic Rf Antenna For In-Vivo Sensing Applications, Shamima Afroz

USF Tampa Graduate Theses and Dissertations

A continuous glucose sensor employing radio frequency (RF) signals is presented using the biocompatible material Silicon Carbide (SiC). Unlike biosensors that require direct contact with interstitial fluids to trigger chemical reactions to operate, this biocompatible SiC sensor does not require a direct interface. The sensing mechanism for this SiC sensor is based upon a shift in resonant frequency, as a function of change in glucose levels, which electrically manifests itself as a change in blood permittivity and

conductivity. For in vivo applications the antenna sensor needs to operate inside the body environment, and it has been found that the best …

A Multi-Parameter Functional Side Channel Analysis Method For Hardware Trojan Detection In Untrusted Fpga Bitstreams, Christopher William Bell

USF Tampa Graduate Theses and Dissertations

Hardware Trojan Horses (HTHs or Trojans) are malicious design modifications intended to cause the design to function incorrectly. Globalization of the IC development industry has created new opportunities for rogue agents to compromise a design in such a way. Offshore foundries cannot always be trusted, and the use of trusted foundries is not always practical or economical. There is a pressing need for a method to reliably detect these Trojans, to prevent compromised designs from being put into production.

This thesis proposes a multi-parameter analysis method that is capable of reliably detecting function-altering and performance-degrading Trojans in FPGA bitstreams. It …

Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime

USF Tampa Graduate Theses and Dissertations

The objective of this work is to examine the effect of cement chemistry and physical properties on activation energy. Research efforts indicated that time dependent concrete properties such as strength, heat evolution, and thermal cracking are predictable through the concept of activation energy. Equivalent age concept, which uses the activation energy is key to such predictions. Furthermore, research has shown that Portland cement concrete properties are affected by particles size distribution, Blaine fineness, mineralogy and chemical composition. In this study, four Portland cements were used to evaluate different methods of activation energy determination based on strength and heat of hydration …