Engineering Commons^™

Miniature Printed Antennas And Filters Using Volumetric Reactive Pins And Lumped Circuit Loadings, Saurabh Gupta

USF Tampa Graduate Theses and Dissertations

This dissertation presents a new technique for miniaturization of printed RF circuits and antennas. The technique is based on lumped circuit elements and volumetric reactive pin loadings. The vertical arrangement of the pins is shown to provide a meandered current path within the device volume enhancing the miniaturization achieved with sole application of lumped circuit components. The technique is applied for antenna and filter size reduction. In antenna applications, it is shown that due to the presence of the reactive pin loading the overall size of a printed antenna can be miniaturized without affecting the radiation efficiency performance. One of …

Miniature Ion Optics Towards A Micro Mass Spectrometer, Ashish Chaudhary

USF Tampa Graduate Theses and Dissertations

This PhD dissertation reports the development of miniature ion optics components of a mass spectrometer (MS) with the ultimate goal to lay the foundation for a compact low-power micromachined MS (µMS) for broad-range chemical analysis. Miniaturization of two specific components a) RF ion traps and b) an ion funnel have been investigated and miniature low-power versions of these components have been developed and demonstrated successfully in lab experiments. Power savings, simpler electronics and packaging schemes required to operate the micro-scale RF cylindrical ion traps have been the key motivation driving this research. Microfabricated cylindrical ion traps (µCITs) and arrays in …

On The Improvement Of The Capacity Of The Heterogeneous Networks With Link-Level And System-Level Approaches, Mehmet Bahadır Çelebi

USF Tampa Graduate Theses and Dissertations

Evolution of wireless services enabled the development of the advanced applications and shifted the paradigms of research in this field from voice to data centric. Such services are spreading like wildfire between users and hence, increasing the demand for large bandwidth. However, the frequency spectrum that is suitable for wireless mobile communications is already assigned to particular services from 400 MHz to several GHz. Also, allocating a large chunk of band continuously from the same part of the spectrum may not be possible due to spectral crowd. Therefore, meeting the demand for high data rate requiring wireless services within the …

Fabrication And Comparison Of Electrospun Cobalt Oxide-Antimony Doped Tin Oxide (Coo-Ato) Nanofibers Made With Ps: D-Limonene And Ps: Toluene, Manopriya Devisetty Subramanyam

USF Tampa Graduate Theses and Dissertations

This work investigates the fabrication, process optimization, and characterization of cobalt oxide-antimony doped tin oxide (CoO-ATO) nanofibersusing polystyrene (PS) solutions with toluene orD-limonene as solvents. These nanofibers are produced by anelectrospinning process. Nanofibers are fabricated using polymeric solutions of CoO doped ATO and mixtures of PS: D-limonene and PS:toluene. PSis a base aromatic organic polymer, a non-toxic material, and a versatile catalyst for fiber formation. PSsolutions are made by mixing polystyrene beads and D-limonene or toluene at specific weight percentages. These polymeric solutions of PS: D-limonene and PS:toluene are then mixed with CoO-ATO at various weight percentages. The two solutions …

Residual-Based Variational Multiscale Les With Wall-Modeling For Oceanic Boundary Layers In Shallow Water, Roozbeh Golshan

USF Tampa Graduate Theses and Dissertations

Large-eddy simulation (LES) of wind and wave forced oceanic turbulent boundary layers is performed using the residual-based variational multiscale method (RBVMS) and near-wall modeling. Wind and surface gravity wave forcing generates Langmuir turbulence characterized by Langmuir circulation (LC) with largest scales consisting of streamwise vortices aligned in the direction of the wind, acting as a secondary flow structure to the primary wind-driven component of the flow. The LES here is representative of a shallow water continental shelf flow (10 to 30 meters in depth) far from lateral boundaries in which LC engulfs the full depth of the water column and …

Quantification Of Protein Adhesion Strength To Surface Attached Poly (N- Isopropylacrylamide) Networks By Hydrodynamic Detachment Shear Stresses, Gulnur Sanden

USF Tampa Graduate Theses and Dissertations

Stimuli responsive coatings offer a versatile method by which to manipulate interfacial interactions of proteins in a desired way. However, there exists little guidance as to how the structure of a responsive polymer coating influences adsorption of proteins. In this dissertation, the adsorption behavior of immuglobulin G (IgG) on poly (N-isopropylacryamide) (PNIPAAm) hydrogel coatings was investigated as a function of film thickness. PNIPAAm exhibits a hydrophilic to hydrophobic transition above a critical temperature of ~32°C in aqueous solutions. In this research, through the use of quartz crystal microbalance with dissipation (QCM-D) it was observed that the adsorption was thickness dependent …

Exploration Of Electrodeposition Of Aluminum-Nickel Alloys And Multilayers In Organic Chloroaluminate Ionic Liquids, Ammar Bin Waqar

USF Tampa Graduate Theses and Dissertations

Aluminum-nickel (Al-Ni) alloys and Al/Ni bilayers were successfully electrodeposited from AlCl₃-EMIM-NiCl₂ electrolyte at room temperature. Dissolution of NiCl₂ was shown to be favorable in Lewis basic (with molar ratio of AlCl₃ < 0.5) AlCl₃-EMIM solution. The use of electrochemically active Cu working electrode as opposed to inert W induced additional Cu oxidation and dissolution in the cyclic voltammetry scan. The reduction potentials of Al and Ni were found to be ~ – 0.3 and 0.15 V vs. Al/Al³⁺ respectively. Increasing [NiCl₂] in the electrolyte leads to an increase of Ni concentration in the …

Reliable Design And Operations Of Infrastructure Systems, Yu An

USF Tampa Graduate Theses and Dissertations

The reliability issue of the infrastructure systems has become one of the major concerns of the system operators. This dissertation is a collection of four published and working papers that address the specific reliable design and operations problems from three different application settings: transportation/telecommunications network, distribution network, and power plant. In these four projects, key random factors like site disruption and uncertain demand are explicitly considered and proper research tools including stochastic programming, robust optimization, and variants of robust optimization are applied to formulate the problems based on which the important and challenging modelling elements (nonlinear congestion, disruption caused demand …

A Passive Membrane Photobioreactor For The Isolated Cultivation Of Algal Resource Utilizing Selectivity (Icarus), With Wastewater As A Feedstock, Ivy Lea Cormier Drexler

USF Tampa Graduate Theses and Dissertations

Renewed momentum in the microalgae industry due to commercial interest in biofuels and bioproducts is driving the need to increase the economic competitiveness of large-scale microalgal production. Current knowledge of membrane systems common in other disciplines, such as environmental engineering, marine science, and biomedicine, are relevant to algae production. With pore sizes ranging from microns to angstroms, membranes provide tailored functions for solid/liquid separation (cell retention, biomass concentration and dewatering), gas/liquid separation (gas delivery and removal), and solute/liquid separation (bioproduct recovery, feedstock preparation and effluent recycling) that are problematic or not possible with other technologies. Though membranes have great potential …

Analysis Of Advanced Supercritical Carbon Dioxide Power Cycles For Concentrated Solar Power Applications, Saeb Mostaghim Besarati

USF Tampa Graduate Theses and Dissertations

Solar power tower technology can achieve higher temperatures than the most common commercial technology using parabolic troughs. In order to take advantage of higher temperatures, new power cycles are needed for generating power at higher efficiencies. Supercritical carbon dioxide (S-CO₂) power cycle is one of the alternatives that have been proposed for the future concentrated solar power (CSP) plants due to its high efficiency. On the other hand, carbon dioxide can also be a replacement for current heat transfer fluids (HTFs), i.e. oil, molten salt, and steam. The main disadvantages of the current HTFs are maximum operating temperature …

Fabrication And Characterization Of Magnetic Nanostructures, Kevin Scott

USF Tampa Graduate Theses and Dissertations

Magnetic permalloy nanostructures were fabricated onto a silicon wafer using electron beam lithography and a liftoff process. The lithography was performed with a Hitachi SU-70 SEM retrofitted with a Nabity NPGS lithography conversion kit. PMMA of 950kDa molecular weight was used as the photoresist. Features were either nanowires, nanodots, or elliptical or rectangular nanostructures. The nanowires had dimensions of 15µm x 200nm x 40nm, the nanodots had diameters of 145nm and thickness of 12nm, and the ellipses and rectangles had dimensions of 110nm x 50nm x 13nm. Characterization of the nanostructures was performed using the same Hitachi SEM as well …

Using Embedded Systems To Determine The Configuration Of A Static Wheelchair Mounted Robotic Arm, Daniel Ashley

USF Tampa Graduate Theses and Dissertations

The calibration of a 9 degree of freedom (DOF) robotic manipulator using multiple three axis accelerometers and an embedded system will be accomplished in this work. The 9-DOF robotic system used in this study is a 7-DOF robotic arm attached to a 2-DOF power wheelchair. Combined they create a Wheelchair Mounted Robotic Arm (WMRA). The problem that will be solved by this thesis is the calibration of the robotic system during start up. The 7 DOF robotic arm is comprised of rotational joints only. These joints have dual channel encoders to determine the joint position, among other useful data. The …

Age And Gender Recognition For Speech Applications Based On Support Vector Machines, Hasan Erokyar

USF Tampa Graduate Theses and Dissertations

Automatic age and gender recognition for speech applications is very important for a number of reasons. One of the reasons is that it can improve human-machine interaction. For example, the advertisements can be specialized based on the age and the gender of the person on the phone. It also can help identify suspects in criminal cases or at least it can minimize the number of suspects. Some other uses of this system can be applied for adaptation of waiting queue music where a different type of music can be played according to the person's age and gender. And also using …

A Decision Support Model For Personalized Cancer Treatment, Florentino Antonio Rico-Fontalvo

USF Tampa Graduate Theses and Dissertations

This work is motivated by the need of providing patients with a decision support system that facilitates the selection of the most appropriate treatment strategy in cancer treatment. Treatment options are currently subject to predetermined clinical pathways and medical expertise, but generally, do not consider the individual patient characteristics or preferences. Although genomic patient data are available, this information is rarely used in the clinical setting for real-life patient care. In the area of personalized medicine, the advancement in the fundamental understanding of cancer biology and clinical oncology can promote the prevention, detection, and treatment of cancer diseases.

The objectives …

Wastewater Nutrient Recovery Using Anaerobic Membrane Bioreactor Permeate For Hydroponic Fertigation, Jorge Luis Calabria

USF Tampa Graduate Theses and Dissertations

The imbalance between global population growth and resource consumption is indicative of unsustainable practices and foreshadows a grim future of continued resource depletion, food and water scarcity, social inequality, and deteriorating public and environmental health. Meanwhile, the urban centers of the world continue to experience exponential growth resulting in overwhelmed food, water, and sanitation infrastructure. Decentralized and satellite wastewater treatment technologies capable of resource recovery, such as anaerobic membrane bioreactors (AnMBR), foster synergistic opportunities to help manage the food, energy, and water sectors of urban environments. Specifically, the nutrient concentration and high effluent quality of permeate produced by AnMBR systems …

Telecommunication Network Survivability For Improved Reliability In Smart Power Grids, Sankalp Mogla

USF Tampa Graduate Theses and Dissertations

Power transmission grid infrastructures deliver electricity across large distance and are vital to the functioning of modern society. Increasingly these setups embody highly-coupled cyber-physical systems where advanced telecommunications networks are used to send status and control information to operate power transmission grid components, i.e., "smart grids". However, due to the high inter-dependency between the communication and power grid network layers, failure events can lead to further loss of control of key grid components, i.e., even if they are undamaged. In turn, such dependencies can exacerbate cascading failures and lead to larger electricity blackouts, particularly under disaster conditions. As a result, …

Exergetic Life Cycle Assessment Of Electrospun Polyvinylidene Fluoride Nanofibers, Salman Ali Abbasi

USF Tampa Graduate Theses and Dissertations

Assessing the sustainability of nanomanufacturing products and processes has been difficult to achieve using conventional approaches mainly due to an inadequate inventory, large process-to-process variation, and a dearth of relevant toxicology data for nanomaterials. Since these issues are long term in nature, it is required to create hybrid methodologies that can work towards filling the existing gaps. Merging thermodynamic techniques such as the exergy analysis with environmental assessments can help make better, more informed choices while providing an opportunity for process improvement by enabling to correctly quantify efficiency loss through the waste stream, and by locating the exact areas for …

Photonic Crystal-Based Flow Cytometry, Justin William Stewart

USF Tampa Graduate Theses and Dissertations

Photonic crystals serve as powerful building blocks for the development of lab-on-chip devices. Currently they are used for a wide range of miniaturized optical components such as extremely compact waveguides to refractive-index based optical sensors. Here we propose a new technique for analyzing and characterizing cells through the design of a micro-flow cytometer using photonic crystals. While lab scale flow cytometers have been critical to many developments in cellular biology they are not portable, difficult to use and relatively expensive. By making a miniature sensor capable of replicating the same functionality as the large scale units with photonic crystals, we …

Human Mirna Sequence Based Variations Database, Nadim Georges Bou Zeidan

USF Tampa Graduate Theses and Dissertations

MicroRNAs (miRNAs) are studied as key genetic elements that regulate the gene expression involved in different human diseases. Clinical sequence based variations like copy number variations (CNVs) affect miRNA biogenesis, dosage and target recognition that may represent potentially functional variants and relevant target bindings.

To systematically analyze miRNA-related CNVs and their effects on related genes, a user-friendly free online database was developed to provide further analysis of co-localization of miRNA loci with human genome CNV regions. Further analysis pipelines such as miRNA-target to estimate the levels or locations of variations for genetic duplications, insertions or deletions were also offered. Such …

Analysis And Prevention Of Code-Injection Attacks On Android Os, Grant Joseph Smith

USF Tampa Graduate Theses and Dissertations

Injection attacks are the top two causes of software errors and vulnerabilities, according to the MITRE Common Vulnerabilities list [1]. This thesis presents a threat analysis of injection attacks on applications built for Android, a popular but not rigorously studied operating system designed for mobile devices. The following thesis is argued: Injection attacks are possible on off-the-shelf Android systems, and such attacks have the capacity to compromise the device through resource denial and leaking private data. Specifically, we demonstrate that injection attacks are possible through the OS shell and through the SQLite API. To mitigate these attacks, we augment the …

Auxiliary Roles In Stt-Mram Memory, Jayita Das

USF Tampa Graduate Theses and Dissertations

Computer memories now play a key role in our everyday life given the increase in the number of connected smart devices and wearables. Recently post-CMOS memory technologies are gaining significant research attention along with the regular ones. Spin Transfer Torque Magnetoresistive RAM (STT-MRAM) is one such post-CMOS memory technology with a rapidly growing commercial interest and potential across diverse application platforms. Research has shown the ability of STT-MRAM to replace different levels of memory hierarchy as well. In brief, STT-MRAM possesses all the favorable properties of a universal memory technology. In this dissertation we have explored the roles of this …

Operation Optimization And Water Quality Simulation Of Potable Water Distribution System, Xiongfei Xie

USF Tampa Graduate Theses and Dissertations

A potable water distribution system (WDS) consists of pipes, pumps, valves, storage tanks, control and supporting components. Traditionally, it has two basic functions. First, provides end users with potable water at sufficient pressures and good water quality. Second, provides sufficient pressure and flow for fire fighting. Currently, potable water is still the least expensive material for fire fighting. To accomplish these two goals, water utilities have to consider the integrity and security of the water network. As a result, this research selected three research topics that are closely related to the daily operation of water utilities and water quality simulation. …

Effects Of Mix Design Using Chloride-Based Accelerator On Concrete Pavement Cracking Potential, Daniel Aaron Buidens

USF Tampa Graduate Theses and Dissertations

Cracked pavement slabs lead to uncomfortable and eventual unsafe driving conditions for motorists. Replacement of cracked pavement slabs can interrupt traffic flow in the form of lane closures. In Florida, the traffic demands are high and pavement repairs need to be carried out swiftly typically using concrete with high cement contents and accelerators to create rapid setting and strength gain. The concrete used in these pavement replacements is usually accompanied by a high temperature rise, making the replaced slabs susceptible to cracking. Cracking is a result of developed tensile stresses in the concrete, which exceed the concrete's tensile strength capacity. …

Investigation Of Enhanced Titanium And Zinc Oxide Semiconductors For The Photodegradation Of Aqueous Organic Compounds, Innocent Udom

USF Tampa Graduate Theses and Dissertations

Growing demand and shortages of potable water sources due to industrialization have become a great concern worldwide. Various approaches and solutions have been adopted to provide cleaner and quality water. In a preliminary study, a method of treating wastewater was investigated in which algae were used to remove nutrients (nitrogen and phosphorous) from wastewater and then the algae were harvested for use as a biofuel. The results from this investigation are included in the Appendix B. Employing traditional oxidants, such as hydrogen peroxide, chlorine, and ozone, for treatment of recalcitrant organic compounds have achieved less promising results. However, photocatalysis, an …

A Hybrid Privacy-Preserving Mechanism For Participatory Sensing Systems, Idalides Jose Vergara

USF Tampa Graduate Theses and Dissertations

Participatory Sensing (PS) is a new data collection paradigm in which people use their cellular phone resources to sense and transmit data of interest to address a collective problem that would have been very difficult to assess otherwise. Although many PS-based applications can be foreseen to solve interesting and useful problems, many of them have not been fully implemented due to privacy concerns. As a result, several privacy-preserving mechanisms have been proposed. This dissertation presents the state-of-the-art of privacy-preserving mechanisms for PS systems. It includes a new taxonomy and describes the most important issues in the design, implementation, and evaluation …

An Analysis Of (Bad) Behavior In Online Video Games, Jeremy Blackburn

USF Tampa Graduate Theses and Dissertations

This dissertation studies bad behavior at large-scale using data traces from online video games. Video games provide a natural laboratory for exploring bad behavior due to their popularity, explicitly defined (programmed) rules, and a competitive nature that provides motivation for bad behavior. More specifically, we look at two forms of bad behavior: cheating and toxic behavior.

Cheating is most simply defined as breaking the rules of the game to give one player an edge over another. In video games, cheating is most often accomplished using programs, or "hacks," that circumvent the rules implemented by game code. Cheating is a threat …

Development Of Electroplated-Ni Structured Micromechanical Resonators For Rf Application, Mian Wei

USF Tampa Graduate Theses and Dissertations

On-chip vibrating MEMS resonators with high frequency-Q product on par with that of the off-chip quartz crystals have attracted lots of attention from both academia and industry for applications on sensing, signal processing, and wireless communication. Up to now, several approaches for monolithic integration of MEMS and transistors have been demonstrated. Vibrating micromechanical disk resonators which utilize electroplated nickel as the structural material along with either a solid-gap high-k dielectric capacitive transducer or a piezoelectric transducer have great potential to offer unprecedented performance and capability of seamless integration with integrated circuits.

Despite the frequency drift problems encountered in early attempts …

A Brain Robot Interface For Autonomous Activities Of Daily Living Tasks, Don Indika Upashantha Pathirage

USF Tampa Graduate Theses and Dissertations

There have been substantial improvements in the area of rehabilitation robotics in the recent past. However, these advances are inaccessible to a large number of people with disabilities who are in most need of such assistance. This group includes people who are in a severely paralyzed state, that they are completely "locked-in" in their own bodies. Such persons usually retain full cognitive abilities, but have no voluntary muscle control.

For these persons, a Brain Computer Interface (BCI) is often the only way to communicate with the outside world and/or control an assistive device. One major drawback to BCI devices is …

Opuntia Ficus-Indica Mucilage Potential To Remove Nuclear Active Contaminants From Water Based On A Surrogate Approach, Jose Adan Leon

USF Tampa Graduate Theses and Dissertations

Potable water is a necessity and unfortunately, it can be contaminated in many different ways. This paper specifically addresses the case scenario when, water has been contaminated by radionuclides. The mucilage of Opuntia ficus-indica (OFI), has been proven to be a great flocculating agent, turbidity reducer, crude oil dispersant and an environmentally friendly substance as an absorbent of water contaminants. In this work, the OFI mucilage was investigate to evaluate its capacity to separate radioactive ions from water. The surrogate approach is modeled based on water studies performed by Willi A. Brand, who proved that radioactive isotopes behave similar to …

Development Of An Efficient Human Hepatocyte Culture Platform For Assessing Novel Therapeutic Efficacy Against Plasmodium Liver Parasites, Steven Patrick Maher

USF Tampa Graduate Theses and Dissertations

Malaria is a critical and global public health problem, affecting over 200 million people every year, resulting in over 500,000 deaths. A vaccine is not currently available and only one drug, primaquine, is effective against the dormant stages of Plasmodium vivax. Preclinical assessment of novel therapeutic drugs and vaccines is hampered by the lack of an in vitro liver model for P. falciparum and P. vivax. To provide a stable human hepatocyte-based culture platform for parasite development, we engineered a microfluidic bilayer device capable of both simple and complex culture methods, including perfusion and co-culture, to better understand the requirements …