Engineering Commons^™

Parallel Confocal Recording Of Localized Retinal Photoreceptor Responses, Qiuxiang Zhang

All ETDs from UAB

The primary purpose of my thesis research is to validate parallel confocal recording of intrinsic optical signals (IOSs) correlated with localized retinal photoreceptor responses. IOS imaging promises a noninvasive method for retinal disease detection and treatment evaluation. However, IOS identification of localized retinal dysfunction is still challenging due to the complexity of retinal structure. Stimulus-evoked IOSs have been observed in both photoreceptors and inner retinal neurons. IOS pattern of retinal photoreceptor layer may contain cross-talk noise from inner retinal layers. In order to detect localized retinal photoreceptors response without significant contamination from other retinal volumes, we designed a rapid functional …

Cyclic Elongation And Pull Out Of Unicortical And Bicortical Suture Anchor Designs, Richard Justin Lesley

All ETDs from UAB

CYCLIC ELONGATION AND PULL OUT OF UNICORTICAL AND BICORTICAL SUTURE ANCHOR DESIGNS JUSTIN LESLEY BIOMEDICAL ENGINEERING ABSTRACT A novel suture anchor design was introduced and biomechanically tested. The novel design involved lengthening a standard metal screw type anchor so as to achieve greater fixation in bone. Along with utilizing a greater amount of trabecular bone, this design also allows a second layer of cortical bone to be involved in order to further enhance fixation. This "bicortcal" design is intended to be used under unique clinical circumstances. Such circumstances may include RC repair in patients with extreme osteoporosis, in cases where …

Optimization And Characterization Of Multifunctional Polymeric-Nanodiamond Electrospun Scaffolds, Amanee Salaam

All ETDs from UAB

Due to the lack of treatment options available for patients suffering from bone abnormalities, current research focuses on developing novel biomaterials for bone tissue engineering. Since a tissue scaffold is implanted in vivo, it could also serve as a substrate for localized, systemic delivery of therapeutics. Particularly in primary bone cancer after removal of a cancerous lesion, there is a need for a system that can support the generation of new tissue while delivering localized chemotherapy. However, a complex molecule is needed to serve as a vehicle for delivering the drug and targeting only cancerous cells. Detonation nanodiamond (DND) is …

Optimization And Characterization Of Bioactive Glass Nanofibers And Nanocomposites, Reginna Evette Scarber

All ETDs from UAB

Disease affects different areas of the bone and can impact individuals of all pathologies and ethnicities. These bone diseases can result in weakening which leads to trauma during ordinary function, the need for reconstructive surgery, and eventual bone replacement. Tissue engineering can provide a less traumatic and more fundamental solution to the current therapies. Bioactive glasses are promising materials in tissue engineering applications because of their ability to form hydroxycarbonate apatite in the presence of simulated body fluid, support cell adhesion, growth, and differentiation, induce bone formation, and concentrate bone morphogenic proteins in vivo. The research in this dissertation will …

Composite Structural Insulated Panels (Csips) For Hazards Resistant Structures, Mohammed Abdel-Moneim Abdel-Raouf Mousa

All ETDs from UAB

Traditional construction materials have numerous shortcomings such as poor durability, low penetration resistance against wind-borne debris and lower strength compared to composites. Accordingly, a new type of Composite Structural Insulated Panels (CSIPs) was developed and evaluated in this study to replace the conventional structural materials. CSIPs are prefabricated components that can be shipped to the site and assembled into the finished structure. These hybrid panels have the potential to be used as structural wall, floor, and roof elements. Analytical and finite element (FE) models were developed in this study to design and simulate the behavior of CSIPs. These models were …

Automated Semantic Understanding Of Human Emotions In Writing And Speech, Ricardo A. Calix

LSU Doctoral Dissertations

Affective Human Computer Interaction (A-HCI) will be critical for the success of new technologies that will prevalent in the 21st century. If cell phones and the internet are any indication, there will be continued rapid development of automated assistive systems that help humans to live better, more productive lives. These will not be just passive systems such as cell phones, but active assistive systems like robot aides in use in hospitals, homes, entertainment room, office, and other work environments. Such systems will need to be able to properly deduce human emotional state before they determine how to best interact with …

Quantitative Carré Differential Interference Contrast Microscopy To Assess Phase And Amplitude, Donald D. Duncan, David G. Fischer, Amanda Dayton, Scott A. Prahl

Electrical and Computer Engineering Faculty Publications and Presentations

We present a method of using an unmodified differential interference contrast microscope to acquire quantitative information on scatter and absorption of thin tissue samples. A simple calibration process is discussed that uses a standard optical wedge. Subsequently, we present a phase-stepping procedure for acquiring phase gradient information exclusive of absorption effects. The procedure results in two-dimensional maps of the local angular (polar and azimuthal) ray deviation. We demonstrate the calibration process, discuss details of the phase-stepping algorithm, and present representative results for a porcine skin sample.

Extraction Of Small Boat Harmonic Signatures From Passive Sonar, George Lloyd Ogden, Lisa M. Zurk, M. E. Jones, M. E. Peterson

Electrical and Computer Engineering Faculty Publications and Presentations

This paper investigates the extraction of acoustic signatures from small boats using a passive sonar system. Noise radiated from a small boats consists of broadband noise and harmonically related tones that correspond to engine and propeller specifications. A signal processing method to automatically extract the harmonic structure of noise radiated from small boats is developed. The Harmonic Extraction and Analysis Tool (HEAT) estimates the instantaneous fundamental frequency of the harmonic tones, refines the fundamental frequency estimate using a Kalman filter, and automatically extracts the amplitudes of the harmonic tonals to generate a harmonic signature for the boat. Results are presented …

Phase Noise In Cmos Phase-Locked Loop Circuits, Yang Liu

LSU Doctoral Dissertations

Phase-locked loops (PLLs) have been widely used in mixed-signal integrated circuits. With the continuously increasing demand of market for high speed, low noise devices, PLLs are playing a more important role in communications. In this dissertation, phase noise and jitter performances are investigated in different types of PLL designs. Hot carrier and negative bias temperature instability effects are analyzed from simulations and experiments. Phase noise of a CMOS phase-locked loop as a frequency synthesizer circuit is modeled from the superposition of noises from its building blocks: voltage-controlled oscillator, frequency divider, phase-frequency detector, loop filter and auxiliary input reference clock. A …

Effects Of Solids Loadings And Particle Size Distribution On Siphon Ceramic Candle Filters, Danielle Renzi

USF Tampa Graduate Theses and Dissertations

In the rural areas of Madagascar only 29% of the population has access to clean water and 10% has access to improved sanitation. It has been estimated that environmental risk factors, such as inadequate access to clean drinking water and proper sanitation, are responsible for 94% of the diarrheal disease burden. This study was focused on testing a point-of-use technology called the Tulip filter, which is a siphon ceramic candle filter impregnated with silver. The purpose is to assess its feasibility for implementation in rural regions of Madagascar through a laboratory study performed at the University of South Florida.

The …

Decision Aid Models For Resource Sharing Strategies During Global Influenza Pandemics, Alfredo Santana Reynoso

USF Tampa Graduate Theses and Dissertations

Pandemic influenza outbreaks have historically entailed significant societal and economic disruptions. Today, our quality of life is threatened by our inadequate preparedness for the imminent pandemic. The key challenges we are facing stem from a significant uncertainty in virus epidemiology, limited response resources, inadequate international collaboration, and the lack of appropriate science-based decision support tools. The existing literature falls short of comprehensive models for global pandemic spread and mitigation which incorporate the heterogeneity of the world regions and realistic travel networks. In addition, there exist virtually no studies which quantify the impact of resource sharing strategies among multiple countries. This …

Feasibility Of Wearable Sensors To Determine Gait Parameters, Mario Alves Simoes

USF Tampa Graduate Theses and Dissertations

A wearable system that can be used in different settings to collect gait parameters on subjects with a mild traumatic brain injury (mTBI) would allow clinicians to collect needed data of subjects outside of the laboratory setting. Mild traumatic brain injuries stem from a number of causes such as illnesses, strokes, accidents or battlefield traumas. These injuries can cause issues with everyday tasks, such as gait, and are linked with vestibular dysfunction [1]. Different wearable sensor systems were analyzed prior to starting this study along with relevant gait parameters associated with mild traumatic brain injury. To monitor gait parameters relevant …

Thermophysical Characterization Of Nanofluids Through Molecular Dynamic Simulations, John Shelton

USF Tampa Graduate Theses and Dissertations

Using equilibrium molecular dynamics simulations, an analysis of the key thermophysical properties critical to heat transfer processes is performed. Replication of thermal conductivity and shear viscosity observations found in experimental investigations were performed using a theoretical nanopthesis-fluid system and a novel colloid-fluid interaction potential to investigate the key nanofluid parameters. Analysis of both the heat current (thermal conductivity) and stress (shear viscosity) autocorrelation functions have suggested that the dominant physical mechanisms for thermal and momentum transport arises from enhancements to the longitudinal and transverse acoustic modes energy transfer brought about by the increased mass ratio of the nanopthesis to the …

Modeling And Parameter Study Of Bistable Spherical Compliant Mechanisms, Chester Smith

USF Tampa Graduate Theses and Dissertations

The bistable spherical compliant mechanism (BSCM) is a novel device capable of large, repeatable, out-of-plane motion, characteristics that are somewhat difficult to achieve with surface micromachined microelectromechanical systems. An improved pseudo-rigid-body model (PRBM) to predict the behavior of the BSCM is presented. The new model was used to analyze seven different versions of the device, each with a different compliant joint length. The new model, which adds torsion, is compared with a finite element analysis (FEA) beam model. The new model more closely approximates the results yielded by FEA than previous models used to analyze the BSCM. Future work is …

Pilot Assessment Of Novel Membrane Bioreactor Processes - Improvements In Biological Nutrient Removal And Membrane Operation, Shaleena Smith

USF Tampa Graduate Theses and Dissertations

With increasing water reuse applications and upcoming stringent regulations for treated wastewater effluent discharge, wastewater plants need to consider alternative technologies beyond conventional treatment processes. The new regulations, Numeric Nutrient Criteria (NNC), may regulate discharge nitrogen and phosphorus concentrations to as low as 0.5 mg/L as N and 10 μg/L as P respectively. To meet these target requirements, system retrofitting to incorporate chemical or advanced nutrient removal systems possibly with membrane technology will most likely be required. Although microfiltration/ultrafiltration membranes coupled with biological processes, otherwise known as membrane bioreactors (MBR), remove contaminants and suspended solids, nutrient removal is minimal to …

A Novel Device For Cell-Cell Electrofusion, Justin T. Stewart

USF Tampa Graduate Theses and Dissertations

Cell transplantation therapy is a potentially powerful tool and can be used to replace defective cells with healthy cells. This offers the possibility of alleviating the destructive symptoms for many diseases such as Parkinson's disease, Alzheimer's disease, stroke, spinal cord trauma, Type I diabetes and many more. While there are many diseases that could be positively impacted from cell transplantation therapy, the focus of this research is insulin dependent, Type I Diabetes.

The Islets of Langerhans are composed of various types of cells located in the pancreas and are responsible for a variety of biochemical functions. Specifically, the beta Islet …

Asymmetric Passive Dynamic Walker Used To Examine Gait Rehabilitation Methods, John Sushko

USF Tampa Graduate Theses and Dissertations

Testing gait rehabilitation devices on humans can be a difficult task, due to the effects of the neurological controls of the human body. This thesis advances the use of a passive dynamic walker (PDW) tuned to have asymmetric gait patterns similar to those with physical impairments to test rehabilitation devices. A passive dynamic walker is a multipendulum system that has a stable gait pattern when walking down a slope without any energy inputs except the forces due to gravity. A PDW model is better suited for testing rehabilitation devices because it has been shown to resemble human gait and separates …

A Discrete-Continuous Modeling Framework For Long-Distance, Leisure Travel Demand Analysis, Caleb Van Nostrand

USF Tampa Graduate Theses and Dissertations

This study contributes to the literature on national long-distance travel demand modeling by providing an analysis of households' annual destination choices and time allocation patterns for long-distance leisure travel purposes. An annual vacation destination choice and time allocation model is formulated to simultaneously predict the different destinations that a household visits and the time it spends on each of these visited destinations, in a year. The model takes the form of a Multiple Discrete-Continuous Extreme Value (MDCEV) structure (Bhat, 2005; Bhat, 2008). The model assumes that households allocate their annual vacation time to visit one or more destinations in a …

Simplified Methodology For Designing Parabolic Trough Solar Power Plants, Ricardo Vasquez Padilla

USF Tampa Graduate Theses and Dissertations

The performance of parabolic trough based solar power plants over the last 25 years has proven that this technology is an excellent alternative for the commercial power industry. Compared to conventional power plants, parabolic trough solar power plants produce significantly lower levels of carbon dioxide, although additional research is required to bring the cost of concentrator solar plants to a competitive level. The cost reduction is focused on three areas: thermodynamic efficiency improvements by research and development, scaling up of the unit size, and mass production of the equipment. The optimum design, performance simulation and cost analysis of the parabolic …

Polydimethylsiloxane Mechanical Properties Measured By Macroscopic Compression And Nanoindentation Techniques, Zhixin Wang

USF Tampa Graduate Theses and Dissertations

In this thesis, the relationship between the elastic modulus of PDMS and the base/agent ratio (the amount of crosslinking) is studied. Reliable macroscopic compression test instrument was developed. Preload method was applied for the nanoindentation flat punch test to develop full contact.

In chapter 2, an easy instrument setup for macroscopic compression test is described. A series of PDMS samples with different base/agent ratios were tested using the macroscopic compression method. The relationship between PDMS elastic modulus and its base/agent ratio was established.

In chapter 3, PDMS nanoindentation DMA tests provide stable data with different test control models. The storage …

The Evaluation Of Hybrid Slurry Resulting From The Introduction Of Additives To Mineral Slurries, Kyle Douglas Yeasting

USF Tampa Graduate Theses and Dissertations

Drilled shaft construction often requires the use of drill slurry to maintain borehole stability during excavation and concreting. While drill slurry may be composed of fluids ranging from air to petroleum, drilled shaft construction typically makes use of water based drilling fluids. Although clean water may be utilized as a drilling fluid, a premixed slurry consisting of water, minerals, and/or polymers is more commonly used. Florida Department of Transportation (FDOT) specifications require the use of mineral slurry for all primary structures. The slurry resists the intrusion of groundwater, slows the outward migration of drilling fluid from the excavation, and aids …

Delayed-Bang Approach Towards More Sustainable Critical Infrastructure Risk Management, C. Ariel Pinto, Michael K. Mcshane, Abhishek S. Pathak

Finance Faculty Publications

This article describes the Delayed Bang Approach for determining the value of risk management alternatives in critical infrastructure security. The discussion includes (1) the need for sustainable risk management (2) the importance of time valuation in evaluating competing loss prevention and loss reduction alternatives, (3) the convergence of deterministic engineering economics, survivability analysis, and probabilistic analysis, and (4) hypothetical examples of the Delayed-Bang Approach and significance towards more sustainable risk management.

The Role Of Feedback In The Assimilation Of Information In Prediction Markets, Richard Donald Jolly

Dissertations and Theses

Leveraging the knowledge of an organization is an ongoing challenge that has given rise to the field of knowledge management. Yet, despite spending enormous sums of organizational resources on Information Technology (IT) systems, executives recognize there is much more knowledge to harvest. Prediction markets are emerging as one tool to help extract this tacit knowledge and make it operational. Yet, prediction markets, like other markets, are subject to pathologies (e.g., bubbles and crashes) which compromise their accuracy and may discourage organizational use.

The techniques of experimental economics were used to study the characteristics of prediction markets. Empirical data was gathered …

Phase Change Materials As A Thermal Storage Device For Passive Houses, Kevin Ryan Campbell

Dissertations and Theses

This study describes a simulation-based approach for informing the incorporation of Phase Change Materials (PCMs) in buildings designed to the "Passive House" standard. PCMs provide a minimally invasive method of adding thermal mass to a building, thus mitigating overheating events. Phase change transition temperature, quantity, and location of PCM were all considered while incrementally adding PCM to Passive House simulation models in multiple climate zones across the United States. Whole building energy simulations were performed using EnergyPlus from the US Department of Energy. A prototypical Passive House with a 1500 Watt electric heater and no mechanical cooling was modeled. The …

Simulation Of A Mobile Robot Navigation System, Ahmed Khusheef, Ganesh Kothapalli, Majid Tolouei Rad

Research outputs 2011

Mobile robots are used in various application areas including manufacturing, mining, military operations, search and rescue missions and so on. As such there is a need to model robot mobility that tracks robot system modules such as navigation system and visi on based object recognition. For the navigation system it is important to locate the position of the robot in surr ounding environment. Then it has to plan a path towards desired destination. The navigation system of a robot has to identify all potential obstacles in order to find a suitable path. The objective of this research is to develop …

Design Of Modular Fixtures Using A 3d-Modelling Approach, U Farhan, M Tolouei-Rad

Research outputs 2011

The need for improved productivity and reduced time to market has been increased significantly in manufacturing processes in recent decades. There are many factors that play a role in providing manufacturing processes with more productivity. One is the use of modular fixtures (MFs). MFs have brought many benefits to manufacturing industries including reduced costs and times of production. An MF can be defined as a complete system that consist different elements for effectively and securely holding the workpiece in place for performing various machining operations. Generally an MF is made by assembling a number of fixture elements in a feasible …

Metal-Semiconductor-Metal (Msm) Photodetectors With Plasmonic Nanogratings, Narottam K. Das, Ayman Karar, C L Tan, Mikhail Vasiliev, Kamal Alameh, Yong Tak Lee

Research outputs 2011

We discuss the light absorption enhancement factor dependence on the design of nanogratings inscribed into metal-semiconductor-metal photodetector (MSM-PD) structures. These devices are optimized geometrically, leading to light absorption improvement through plasmon-assisted effects. Finite-difference time-domain (FDTD) simulation results show ~50 times light absorption enhancement for 850 nm light due to improved optical signal propagation through the nanogratings. Also, we show that the light absorption enhancement is strongly dependent on the nanograting shapes in MSM-PDs.

High-Responsivity Plasmonics-Based Gaas Metal-Semiconductor-Metal Photodetectors, Ayman Karar, Narottam Das, Chee Leongtan, Kamal Alameh, Yong Tak Lee, Fouad Karouta

Research outputs 2011

We report the experimental characterization of high-responsivity plasmonics-based GaAs metal-semiconductor-metal photodetector (MSM-PD) employing metal nano-gratings. Both the geometry and light absorption near the designed wavelength are theoretically and experimentally investigated. The measured photocurrent enhancement is 4-times in comparison with a conventional single-slit MSM-PD. We observe reduction in the responsivity as the bias voltage increases and the input light polarization varies. Our experimental results demonstrate the feasibility of developing a high-responsivity, low bias-voltage high-speed MSM-PD.

Correlations Between Index Properties And Unconfined Compressive Strength Of Weathered Ocala Limestone, Raoaa Farah

UNF Graduate Theses and Dissertations

Weathering has a negative effect on both physical and engineering properties of rock specimens and rock masses. When rock masses are weathered it is often difficult to obtain core segments that are the correct size for unconfined compressive strength testing. Thus engineers must use index testing to estimate the strength of specimens for design purposes. This thesis relates the unconfined compressive strength to index strength tests of Ocala limestone. The relationships developed include weathering states of the specimens and proximity of unconfined compressive strength specimens to index specimens.

One hundred and ninety five specimens were classified using International Society for …

Forward Error Correction In Memoryless Optical Modulation, David Rhys Jones

UNF Graduate Theses and Dissertations

The unprecedented growth in demand for digital media has led to an all-time high in society’s demand for information. This demand will in all likelihood continue to grow as technology such as 3D television service, on-demand video and peer-to-peer networking continue to become more common place. The large amount of information required is currently transmitted optically using a wavelength division multiplexing (WDM) network structure. The need to increase the capacity of the existing WDM network infrastructure efficiently is essential to continue to provide new high bandwidth services to end-users, while at the same time minimizing network providers’ costs. In WDM …