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Graduate Theses and Dissertations

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Full-Text Articles in Engineering

A Comparative Study Of Signal Processing Methods For Fetal Phonocardiography Analysis, Venkata Akshay Bhargav Krishna Vadali Jul 2018

A Comparative Study Of Signal Processing Methods For Fetal Phonocardiography Analysis, Venkata Akshay Bhargav Krishna Vadali

Graduate Theses and Dissertations

More than one million fetal deaths occur in the United States every year [1]. Monitoring the long-term heart rate variability provides a great amount of information about the fetal health condition which requires continuous monitoring of the fetal heart rate. All the existing technologies have either complex instrumentation or need a trained professional at all times or both. The existing technologies are proven to be impractical for continuous monitoring [2]. Hence, there is an increased interest towards noninvasive, continuous monitoring, and less expensive technologies like fetal phonocardiography.

Fetal Phonocardiography (FPCG) signal is obtained by placing an acoustic transducer on the ...


Microwave Characterization Of Printable Dielectric Inks Using Additive Manufacturing Methods, Seth York Jul 2018

Microwave Characterization Of Printable Dielectric Inks Using Additive Manufacturing Methods, Seth York

Graduate Theses and Dissertations

Two methods of dielectric characterization are presented that offer quick and cost-effective solutions for screening complex dielectric material properties. Through Direct-Print Additive Manufacturing (DPAM) methods, a dielectric material of choice is dispensed into a capacitor structure and characterized through 1-port s-parameter measurements. The presented methods use fixtures that are modeled and validated through simulation then implemented in practice. Advanced simulations are performed to gain insights which are used to optimize the dielectric characterization performance of the fixtures. Additional investigations are performed which investigate the durability of the fixture and material within by exposing the combination to rough environmental conditions for ...


Validating The Accuracy Of Neatwork, A Rural Gravity Fed Water Distribution System Design Program, Using Field Data In The Comarca Ngöbe-Bugle, Panama, Maria Briones Jul 2018

Validating The Accuracy Of Neatwork, A Rural Gravity Fed Water Distribution System Design Program, Using Field Data In The Comarca Ngöbe-Bugle, Panama, Maria Briones

Graduate Theses and Dissertations

Despite the sustainable development goals to increase access to improved water there are still 884 million people in the world without access to an improved water source (WHO, 2017). One method to improve access to water in rural, mountainous areas, is through construction of gravity fed water distribution systems. These systems should be designed based upon fundamental principles of hydraulics. One method of doing so in a time efficient manner with minimal engineering knowledge is to utilize a downloadable computer program such as Neatwork, which aids in design of rural, gravity fed water distribution systems and has been used by ...


Connected Autonomous Vehicles: Capacity Analysis, Trajectory Optimization, And Speed Harmonization, Amir Ghiasi Jul 2018

Connected Autonomous Vehicles: Capacity Analysis, Trajectory Optimization, And Speed Harmonization, Amir Ghiasi

Graduate Theses and Dissertations

Emerging connected and autonomous vehicle technologies (CAV) provide an opportunity to improve highway capacity and reduce adverse impacts of stop-and-go traffic. To realize the potential benefits of CAV technologies, this study provides insightful methodological and managerial tools in microscopic and macroscopic traffic scales. In the macroscopic scale, this dissertation proposes an analytical method to formulate highway capacity for a mixed traffic environment where a portion of vehicles are CAVs and the remaining are human-driven vehicles (HVs). The proposed analytical mixed traffic highway capacity model is based on a Markov chain representation of spatial distribution of heterogeneous and stochastic headways. This ...


The Effect Of Processing Conditions On The Energetic Diagram Of Cdte Thin Films Studied By Photoluminescence, Shamara P. Collins Jul 2018

The Effect Of Processing Conditions On The Energetic Diagram Of Cdte Thin Films Studied By Photoluminescence, Shamara P. Collins

Graduate Theses and Dissertations

The photovoltaic properties of CdTe-based thin films depend on recombination levels formed in the CdTe layer and at the heterojunction. The localized states are resultant of structural defects (metal sublattice, chalcogen sublattice, interstitial), controlled doping, deposition process, and/or post-deposition annealing. The photoluminescence study of CdTe thin films, from both the bulk and heterojunction, can reveal radiative states due to different defects or impurities. Identification of defects allows for potential explanation of their roles and influence on solar cell performance. A thorough understanding of the material properties responsible for solar cell performance is critical in further advancing the efficiency of ...


A Quantitative Analysis Of Shape Characteristics Of Marine Snow Particles With Interactive Visualization: Validation Of Assumptions In Coagulation Models, Palak P. Dave Jun 2018

A Quantitative Analysis Of Shape Characteristics Of Marine Snow Particles With Interactive Visualization: Validation Of Assumptions In Coagulation Models, Palak P. Dave

Graduate Theses and Dissertations

The Deepwater Horizon oil spill that started on April 20, 2010, in the Gulf of Mexico was the largest marine oil spill in the history of the petroleum industry. There was an unexpected and prolonged sedimentation event of oil-associated marine snow to the seafloor due to the oil spill. The sedimentation event occurred because of the coagulation process among oil associated marine particles. Marine scientists are developing models for the coagulation process of marine particles and oil, in order to estimate the amount of oil that may reach the seafloor along with marine particles. These models, used certain assumptions regarding ...


Channel Camouflage And Manipulation Techniques In Wireless Networks, Song Fang Jun 2018

Channel Camouflage And Manipulation Techniques In Wireless Networks, Song Fang

Graduate Theses and Dissertations

The security of wireless networks and systems is becoming increasingly important as wireless devices are more and more ubiquitous nowadays. The wireless channel exhibits the spatial uncorrelation property, which is that the characteristics of a wireless channel become uncorrelated every half carrier wavelength over distance. This property has prompted an emerging research area that utilizes wireless channel characteristics to achieve location distinction, to detect location changes or facilitate authentication of wireless users, and to establish shared secret key between legitimate communicators. This dissertation includes two work toward the security improvement of existing wireless networks and systems. With the discovered channel ...


Expediting The Consolidation Of Clayey Soils Utilizing Microwaves, Thilini Jayatissa Jun 2018

Expediting The Consolidation Of Clayey Soils Utilizing Microwaves, Thilini Jayatissa

Graduate Theses and Dissertations

Post-construction settlement has been an issue in the field of construction due to the excessive time taken for the dissipation of pore water pressure. This is significant for construction carried out on clayey soils primarily due to the low permeability of clayey soils. Therefore, attention has been directed at finding means of increasing the rate of pre-consolidation. Recent research has focused on the effects of temperature on consolidation. It has been shown that elevated temperature increases the hydraulic conductivity of pore water due to both the reduction of viscosity and differential volumetric expansion of soil and water. This results in ...


Effects Of Body Temperature And General Anesthetics On Intraocular Pressure In Rats, Aditi Pillai Jun 2018

Effects Of Body Temperature And General Anesthetics On Intraocular Pressure In Rats, Aditi Pillai

Graduate Theses and Dissertations

Ocular hypertension has been identified as the fundamental risk factor in glaucoma which is the leading cause for irreversible blindness in the world. Understanding the different factors that affect IOP is of utmost importance in clinical management as IOP is considered as the fundamental factor in assessing the efficiency of glaucoma medications. Several studies have attempted to assess factors that could affect IOP including age, body position, blood pressure, anesthetics commonly used during eye operations, etc. However, in most of these studies IOP is measured under anesthesia using rodent models and these anesthetics could affect the IOP measurements directly or ...


Hydraulic Performance And Vulnerability On Sanitary Sewer Overflow In Southern Pinellas County, Fl, Uchechi O. Akabogu Jun 2018

Hydraulic Performance And Vulnerability On Sanitary Sewer Overflow In Southern Pinellas County, Fl, Uchechi O. Akabogu

Graduate Theses and Dissertations

Rain-induced sanitary sewer overflow due to high infiltration is a significant challenge for many utilities, including Pinellas County utilities. The main aim of this study is to develop a hydraulic model to analyze the performance of the existing sanitary sewer system, especially during intense rainfall events.

To calculate the flow inputs for the model, a times series analysis was performed to separate the inflow and infiltration from the actual sewer flow. Using the Stevens-Schutzbach method, daily Base Infiltration (BI) was calculated and was subtracted from the total observed flow to give the Dry Weather Flow (DWF). Adjusting the DWF by ...


Efficient Adjacency Queries And Dynamic Refinement For Meshfree Methods With Applications To Explicit Fracture Modeling, James Olliff Jun 2018

Efficient Adjacency Queries And Dynamic Refinement For Meshfree Methods With Applications To Explicit Fracture Modeling, James Olliff

Graduate Theses and Dissertations

Meshfree methods provide a more practical approach to solving problems involving large deformation and modeling fracture compared to the Finite Element Method (FEM). However meshfree methods are more computationally intensive compared to FEM, which can limit their practicality in engineering. Meshfree methods also lack a clear boundary definition, restricting available visualization techniques. Determining particle locations and attributes such that a consistent approximation is ensured can be challenging in meshfree methods, especially when employing h-refinement. The primary objective of this work is to address the limitations associated with computational efficiency, meshfree domain discretization, and h-refinement, including both placement of particles as ...


Underground Stormwater Treatment Performance In Urban Coastal Catchments: Case Study Of Baffle Boxes In The City Of Tampa, Awet Eyob Tsegay Jun 2018

Underground Stormwater Treatment Performance In Urban Coastal Catchments: Case Study Of Baffle Boxes In The City Of Tampa, Awet Eyob Tsegay

Graduate Theses and Dissertations

In coastal urban regions, underground stormwater treatment units are suitable infrastructure options because they take less space where premium land is expensive. Even then, they should be accessible and ideally small enough to fit into existing stormwater networks. Since 2003, the City of Tampa and Florida’s Department of Transportation (FDOT) have installed 47 baffle boxes into the city’s stormwater pipe networks. Baffle boxes are underground stormwater treatment structures designed to capture sediments and floating debris. Since their deployment, many challenges regarding their practical sediment capturing performance was raised by the city.

The objective of this research was to ...


Caregiver Perception And The Role Of Seasonality In Under-Five Childhood Diarrhea Incidence In Svay Rieng Province, Cambodia, Brian S. Wells Jun 2018

Caregiver Perception And The Role Of Seasonality In Under-Five Childhood Diarrhea Incidence In Svay Rieng Province, Cambodia, Brian S. Wells

Graduate Theses and Dissertations

Diarrheal disease has long been known to be a burden to children worldwide. Although child mortality rates as a result of diarrhea have decreased over the past two decades, overall diarrhea incidence has remained relatively stable. In Cambodia, diarrhea was the third most prevalent outpatient diagnosis for children under five in 2012, with a reported incidence rate of 12 per 100 children, up from 7 per 100 children in 2008 (Ministry of Planning Cambodia, 2012). Cambodia is an agricultural country with 80% of the population living in rural areas (National Institute of Statistics Ministry of Planning, 2013). Many are also ...


Regulatory Methodology And Unmitigated Wetland Loss In Southwest Florida, Kathleen B. Castor Jun 2018

Regulatory Methodology And Unmitigated Wetland Loss In Southwest Florida, Kathleen B. Castor

Graduate Theses and Dissertations

This research used Geographical Information System (GIS) data to estimate the acreage of wetland loss due to small-scale activities (taking into account exempt, permitted, and unauthorized activities) in the Southwest District of the Department of Environmental Protection (DEP) between 2006 and 2011 and compared that net loss with the unmitigated wetland net loss that DEP documented during that time for authorized activities and violations that were discovered. The comparison allowed an estimation of the extent of undocumented small-scale unmitigated wetland loss that occurred during those six years. DEP records show that 88% of non-compliance cases remain unresolved, and the net ...


Dynamic Modeling Of An Advanced Wastewater Treatment Plant, Komal Rathore Jun 2018

Dynamic Modeling Of An Advanced Wastewater Treatment Plant, Komal Rathore

Graduate Theses and Dissertations

Advanced wastewater treatment plants have complex biological kinetics, time variant influent rates and long processing times. The modeling and operation control of wastewater treatment plant gets complicated due to these characteristics. However, a robust operational system for a wastewater treatment plant is necessary to increase the efficiency of the plant, reduce energy cost and achieve environmental discharge limits. These discharge limits are set by the National Pollutant Discharge Elimination System (NPDES) for municipal and industrial wastewater treatment plants to limit the amount of nutrients being discharged into the aquatic systems.

This document summarizes the research to develop a supervisory operational ...


Simulation Of Turbulent Air Jet Impingement For Commercial Cooking Applications, Shantanu S. Shevade Jun 2018

Simulation Of Turbulent Air Jet Impingement For Commercial Cooking Applications, Shantanu S. Shevade

Graduate Theses and Dissertations

The research work in this dissertation focuses on turbulent air jet heat transfer for commercial cooking applications.

As a part of this study, convective heat transfer coefficient and its interdependency with various key parameters is analyzed for single nozzle turbulent jet impingement. Air is used as the working fluid impinging on the flat surface. A thorough investigation of velocity and temperature distributions is performed by varying nozzle velocity and height over diameter ratio (H/D). Nusselt number and Turbulent Energy are presented for the impingement surface. It was found that for H/D ratios ranging between 6 and 8, nozzle ...


Framework Integrating Climate Model, Hydrology, And Water Footprint To Measure The Impact Of Climate Change On Water Scarcity In Lesotho, Africa, John W. Pryor Jun 2018

Framework Integrating Climate Model, Hydrology, And Water Footprint To Measure The Impact Of Climate Change On Water Scarcity In Lesotho, Africa, John W. Pryor

Graduate Theses and Dissertations

Water scarcity is a problem that will be exacerbated by climate change. Being able to model the effect of climate change on water scarcity is important to effectively plan the use of future water resources. This research integrated the Soil and Water Assessment Tool (SWAT), climate model, and water footprint analysis to measure the impact of climate change on future water scarcity. This was achieved through two objectives. The first objective was to create a modeling framework that links the output from climate model to SWAT and combined streamflow outputs from SWAT with water footprint analysis to measure how climate ...


An Evaluation Of Pit Latrines And User Perception Of Excrement In Ngäbe Communities In Panama, James A. Libby May 2018

An Evaluation Of Pit Latrines And User Perception Of Excrement In Ngäbe Communities In Panama, James A. Libby

Graduate Theses and Dissertations

At the end of the Millennium Development Goal (MDG) period in 2015, 2.3 billion people, 31% of the global population, still did not have access to even basic sanitation services. Of these people, 892 million still practice open defecation, and 856 million people use unimproved facilities such as pit latrines without a slab or platform or hanging latrines or bucket latrines (JMP 2017). Sustainable Development Goal (SDG) Target 6.2 now aims to achieve adequate and equitable sanitation and hygiene for all and sets the ambitious target of eradicating open defecation by 2030. While the number of people open ...


Physical And Social Systems Resilience Assessment And Optimization, Daniel Romero Rodriguez May 2018

Physical And Social Systems Resilience Assessment And Optimization, Daniel Romero Rodriguez

Graduate Theses and Dissertations

Resilience has been measured using qualitative and quantitative metrics in engineering,economics, psychology, business, ecology, among others. This dissertation proposes a resilience metric that explicitly incorporates the intensity of the disruptive event to provide a more accurate estimation of system resilience. A comparative analysis between the proposed metric and average performance resilience metrics for linear and nonlinear loss and recovery functions suggests that the new metric enables a more objective assessment of resilience for disruptions with different intensities. Moreover, the proposed metric is independent of a control time parameter. This provides a more consistent resilience estimation for a given system ...


Towards Utilization Of Distributed On-Chip Power Delivery Against Em Side-Channel Attacks, Ahmed Waheed Khan Apr 2018

Towards Utilization Of Distributed On-Chip Power Delivery Against Em Side-Channel Attacks, Ahmed Waheed Khan

Graduate Theses and Dissertations

Non-invasive side-channel attacks (SCAs) are potent attacks on a cryptographic circuit that can reveal its secret key without requiring lots of equipment. EM side-channel leakage is typically the derivative of the power consumption profile of a circuit. Since the fluctuations of the supply voltage strongly depend on the topology and features of the power distribution network (PDN), design of the PDN has a direct impact on EM side-channel leakage signature.

In this thesis, we explore the security implications of distributed on-chip voltage regulators against EM side-channel attacks. Extensive HFSS simulations have demonstrated that the maximum EM radiation can be reduced ...


Investigations On Frp-Concrete Bond, Mostfa Al Azzawi Apr 2018

Investigations On Frp-Concrete Bond, Mostfa Al Azzawi

Graduate Theses and Dissertations

This dissertation presents findings from three separate investigations, a laboratory study and two field studies that evaluated the durability of the Fiber Reinforced Polymer (FRP)-concrete bond. The laboratory study explored the role of porosity on CFRP-concrete bond following immersion in warm water. Two disparate field studies measured residual bond after 20 years outdoor exposure of FRP repairs of full-size masonry walls and after 12 years for partially submerged piles supporting the Friendship Trail Bridge, Tampa Bay.

The ACI 440 code requires the same surface preparation for all externally bonded FRP concrete repairs. This disregards the role of porosity that ...


Initial Beam Access Schemes For Millimeter Wave Cellular Networks, Mohammed Jasim Apr 2018

Initial Beam Access Schemes For Millimeter Wave Cellular Networks, Mohammed Jasim

Graduate Theses and Dissertations

Millimeter wave technologies present an appealing solution for increasing data throughputs as they provide abundant contiguous channel bandwidths as compared to conventional microwave networks. However, millimeter wave technologies suffer from severe propagation limitations and channel impairments such as atmospheric attenuation and absorption, path and penetration losses, and blockage sensitivity. Therefore, phased arrays and beamforming technologies are necessary to compensate for the degraded signal levels due to the aforementioned factors. Namely, base stations and mobile stations utilize directional transmission in the control- and data- plane for an enhanced channel capacity, which results in initial access challenges due to the absence of ...


Multi-Objective Resource Provisioning In Network Function Virtualization Infrastructures, Diogo Oliveira Apr 2018

Multi-Objective Resource Provisioning In Network Function Virtualization Infrastructures, Diogo Oliveira

Graduate Theses and Dissertations

Network function virtualization (NFV) and software-dened networking (SDN) are two recent networking paradigms that strive to increase manageability, scalability, pro- grammability and dynamism. The former decouples network functions and hosting devices, while the latter decouples the data and control planes. As more and more service providers adopt these new paradigms, there is a growing need to address multi-failure conditions, particularly those arising from large-scale disaster events. Overall, addressing the virtual network function (VNF) placement and routing problem is crucial to deploy NFV surviv- ability. In particular, many studies have inspected non-survivable VNF provisioning, however no known work have proposed survivable ...


Integration And Cross-Coupling Of A Notched-Turbine Symbiotic Power Source For Implantable Medical Devices, Samuel Perez Apr 2018

Integration And Cross-Coupling Of A Notched-Turbine Symbiotic Power Source For Implantable Medical Devices, Samuel Perez

Graduate Theses and Dissertations

The purpose of this research is to design and integrate a symbiotic notched-turbine energy generator for implantation as a cross-coupled system capable of continuously and perpetually powering an electronic implantable medical device (IMD), which is a device designed to operate inside the body of a higher mammal to enhance, correct or provide the body with a function that has deviated from the norm or has stopped altogether. The list of IMDs available for implantation keeps growing every year, one of the newest being the VBLOC, produced by EnteroMedics®, and approved by the Food and Drug Administration (FDA) on January 15th ...


Computational Discovery Of Energetic Polynitrogen Compounds At High Pressure, Brad A. Steele Apr 2018

Computational Discovery Of Energetic Polynitrogen Compounds At High Pressure, Brad A. Steele

Graduate Theses and Dissertations

High-nitrogen-content energetic compounds containing multiple N-N bonds are an attractive alternative towards developing new generation of environmentally friendly, and more powerful energetic materials. High-N content translates into much higher heat of formation resulting in much larger energy output, detonation pressure and velocity upon conversion to large amounts of non-toxic, strongly bonded N2 gas. This thesis describes recent advances in the computational discovery of group-I alkali and hydrogen polynitrogen materials at high pressures using powerful first-principles evolutionary crystal structure prediction methods. This is highlighted by the discovery of a new family of materials that consist of long-sought after all-nitrogen N􀀀 5 ...


In Situ Extrinsic Doping Of Cdte Thin Films For Photovoltaic Applications, Imran Suhrid Khan Mar 2018

In Situ Extrinsic Doping Of Cdte Thin Films For Photovoltaic Applications, Imran Suhrid Khan

Graduate Theses and Dissertations

The Cadmium Telluride thin film solar cell is one of the leading photovoltaic technologies. Efficiency improvements in the past decade made it a very attractive and practical source of renewable energy. Considering the theoretical limit, there is still room for improvement, especially the cell’s open circuit voltage (VOC). To improve VOC, the p-type carrier concentration and minority carrier lifetime of the CdTe absorber needs to be improved. Both these parameters are directly related to the point defect distribution of the semiconductor, which is a function of deposition stoichiometry, dopant incorporation and post-deposition treatments.

CdTe films were deposited by the ...


Three Dimensional Direct Print Additively Manufactured High-Q Microwave Filters And Embedded Antennas, Derar Fayez Hawatmeh Mar 2018

Three Dimensional Direct Print Additively Manufactured High-Q Microwave Filters And Embedded Antennas, Derar Fayez Hawatmeh

Graduate Theses and Dissertations

The need for miniaturized, and high performance microwave devices has focused significant attention onto new fabrication technologies that can simultaneously achieve high performance and low manufacturing complexity. Additive manufacturing (AM) has proven its capability in fabricating high performance, compact and light weight microwave circuits and antennas, as well as the ability to achieve designs that are complicated to fabricate using other manufacturing approaches. Direct print additive manufacturing (DPAM) is an emerging AM process that combines the fused deposition modeling (FDM) of thermoplastics with micro-dispensing of conductive and insulating pastes. DPAM has the potential to jointly combine high performance and low ...


Promoter Effects On Iron-Based, Sba-15 Supported Ultra-High Temperature Fischer- Tropsch Catalysts, David P. Weber Mar 2018

Promoter Effects On Iron-Based, Sba-15 Supported Ultra-High Temperature Fischer- Tropsch Catalysts, David P. Weber

Graduate Theses and Dissertations

Promoter effects on SBA-15 supported iron Fischer-Tropsch catalysts were investigated for their potential to improve high temperature catalyst performance. FTS catalysts promoted by manganese (0.15%-1.4%), copper (0.15%-1%), and potassium (0.5%-3%), with all percentages stated on the basis of mass percentage of final catalysts, were prepared and tested at 430°C and ambient pressure in a fixed bed reactor. Manganese showed the ability to promote the FT reaction, increasing both the CO conversion and the average chain length of hydrocarbon products. Compared to the unpromoted catalyst composed only of iron supported on SBA-15, 1 ...


Assessment Of Drinking Water Quality Management And A Treatment Feasibility Study For Brick By Brick Water Storage Tanks In Rakai Uganda, James V. Murduca Mar 2018

Assessment Of Drinking Water Quality Management And A Treatment Feasibility Study For Brick By Brick Water Storage Tanks In Rakai Uganda, James V. Murduca

Graduate Theses and Dissertations

Reliable access to safe drinking water is one necessity for humans to live without concern for major health risks. The overall goal of this research is to improve the public health, through improved drinking water, for communities in the Rakai District in Uganda, directly, and other communities in the world, indirectly, via dissemination of knowledge. This study specifically assessed the knowledge of drinking water quality in regards to public health, their sanitation measures, and water treatment methods for users of Brick by Brick rainwater harvesting tanks in the Rakai District (N = 28) by using a knowledge, attitudes, and practice survey ...


Field Testing Of Affordable Well Head Protection For Locally Manufactured, Self-Supply Pitcher Pumps On Manually Driven Tubewells In Madagascar, Michal Usowicz Mar 2018

Field Testing Of Affordable Well Head Protection For Locally Manufactured, Self-Supply Pitcher Pumps On Manually Driven Tubewells In Madagascar, Michal Usowicz

Graduate Theses and Dissertations

Lack of water access is an issue of global importance. The WHO and UNICEF’s Joint Monitoring Program estimated that in 2015 71% of the world’s population used a safely managed drinking water source and 89% of the world’s population used an improved water source within a 30-minute round trip of home. Madagascar’s national statistics lags far behind these global statistics with 54% of the population using improved water sources, 31% using unimproved water sources, and 16% with no service at all.

This research studied water access in Madagascar with self-supply Pitcher Pumps attached on hand-driven tubewells ...