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Analysis Of Heat Transfer On Turbulence Generating Ribs Using Dynamic Mode Decomposition, Michael Elmore
Analysis Of Heat Transfer On Turbulence Generating Ribs Using Dynamic Mode Decomposition, Michael Elmore
Electronic Theses and Dissertations
Ducts with turbulence-promoting ribs are common in heat transfer applications. This study uses a recent modal extraction technique called Dynamic Mode Decomposition (DMD) to determine mode shapes of the spatially and temporally complex flowfield inside a ribbed duct. One subject missing from current literature is a method of directly linking a mode to a certain engineering quantity of interest. Presented is a generalized methodology for producing such a link utilizing the data from the DMD analysis. Theory suggests exciting the modes which are identified may cause the flow to change in such a way to promote the quantity of interest, …
Investigation Of A Self-Powered Fontan Concept Using A Multiscale Computational Fluid-Structure Interaction Model, Kyle Beggs
Electronic Theses and Dissertations
Congenital Heart Disease (CHD) occurs in about 1\% (40,000) of newborn babies each year in the United States alone. About 10.9\% (960) of whom suffer from Hypoplastic Left Heart Syndrome (HLHS) - a subset of CHD where children are born with a single-ventricle (SV). A series of three surgeries are carried out to correct HLHS culminating in the Fontan procedure where venous flow returns passively to the lungs. The current configuration for the Fontan results in elevated Central Venous Pressure (CVP), inadequate ventricular preload, and elevated Pulmonary Vascular Resistance (PVR) leading to a barrage of disease. To alleviate these complications, …
Design And Implementation Of Pv-Firming And Optimization Algorithms For Three-Port Microinverters, Mahmood Alharbi
Design And Implementation Of Pv-Firming And Optimization Algorithms For Three-Port Microinverters, Mahmood Alharbi
Electronic Theses and Dissertations
With the demand increase for electricity, the ever-increasing awareness of environmental issues, coupled with rolling blackouts, the role of renewable energy generation is increasing along with the thirst for electricity and awareness of environmental issues. This dissertation proposes the design and implementation of PV-firming and optimization algorithms for three-port microinverters. Novel strategies are proposed in Chapters 3 and 4 for harvesting stable solar power in spite of intermittent solar irradiance. PV firming is implemented using a panel-level three-port grid-tied PV microinverter system instead of the traditional high-power energy storage and management system at the utility scale. The microinverter system consists …
Detailed Understanding Of Flow, Heat Transfer, And Pressure Drop Behavior In A Square Channel With 45 Deg Ribs, Lumaya Ahmed
Detailed Understanding Of Flow, Heat Transfer, And Pressure Drop Behavior In A Square Channel With 45 Deg Ribs, Lumaya Ahmed
Electronic Theses and Dissertations
Internal Duct Cooling (IDC) with rib turbulators is one of the common cooling techniques applied inside the turbine airfoils. It is very important for the gas turbine industry to design and develop an optimized cooling channel that maximizes the amount of heat removed, while simultaneously minimizing the pressure drop for a target overall cooling effectiveness. Angled ribs perform superior to the transverse ribs due to additional secondary flow associated with them. However, they result in a highly non-homogenous heat transfer distribution, which is a manifestation of the complex, turbulent flow field inside the channel. It is very important to comprehend …
Performance Predication Model For Advance Traffic Control System (Atcs) Using Field Data, Masood Mirza
Performance Predication Model For Advance Traffic Control System (Atcs) Using Field Data, Masood Mirza
Electronic Theses and Dissertations
Reductions in capital expenditure revenues have created greater demands from users for quality service from existing facilities at lower costs forcing agencies to evaluate the performance of projects in more comprehensive and "greener" ways. The use of Adaptive Traffic Controls Systems (ATCS) is a step in the right direction by enabling practitioners and engineers to develop and implement traffic optimization strategies to achieve greater capacity out of the existing systems by optimizing traffic signal based on real time traffic demands and flow pattern. However, the industry is lagging in developing modeling tools for the ATCS which can predict the changes …
Use Of Accelerated Calcite Precipitation Method To Investigate Calcium Carbonate Precipitation From Recycled Concrete For Drainage System Applications, Toni Curate
Electronic Theses and Dissertations
Recycled concrete aggregate (RCA) is a sustainable construction material that is a viable option for use in drainage systems by replacing virgin aggregate. Replacing virgin aggregate with RCA is beneficial from both economic and environmental perspectives. However, the use of RCA as pipe backfill materials may cause a long-term performance issue such as potential clogging due to fines accumulation and calcite precipitation on filter fabric. Previous studies investigated the long-term performance of RCA regarding flow rate. Therefore, this study investigated calcite precipitation potential of RCA. The Accelerated Calcite Precipitation (ACP) procedure was devised and used to estimate "life-time" calcite precipitation …
A Framework For Prioritizing Opportunities Of Improvement In The Context Of Business Excellence Model In Healthcare Organization, Alia Aldarmaki
A Framework For Prioritizing Opportunities Of Improvement In The Context Of Business Excellence Model In Healthcare Organization, Alia Aldarmaki
Electronic Theses and Dissertations
In today's world, the healthcare sector is facing challenges to improve the efficiency and effectiveness of its operations. More and more improvement projects are being adopted to enhance healthcare services, making it more patient-centric, and enabling better cost control. Healthcare organizations strive to identify and carry out such improvement initiatives to sustain their businesses and gain competitive advantage. Seeking to reach a higher operational level of excellence, healthcare organizations utilize business excellence criteria to conduct assessment and identify organizational strengths and weaknesses. However, while such assessments routinely identify numerous areas for potential improvement, it is not feasible to conduct all …
Econometric Modeling Analysis Of Public Transit Ridership: Application For Orlando Region, Moshiur Rahman
Econometric Modeling Analysis Of Public Transit Ridership: Application For Orlando Region, Moshiur Rahman
Electronic Theses and Dissertations
Policy makers are considering several alternatives to counter the negative externalities of personal vehicle dependence. Towards this end, public transit investments are critical in growing urban regions such as Orlando, Florida. Transit system managers and planners mostly rely on statistical models to identify the factors that affect ridership as well as quantifying the magnitude of the impact on the society. These models provide vital feedback to agencies on the benefits of public transit investments which in turn act as lessons to improve the investment process. We contribute to public transit literature by addressing several methodological challenges for transit ridership modeling. …
Ignition Studies Of Oxy-Syngas/Co2 Mixtures Using Shock Tube For Cleaner Combustion Engines, Samuel Barak
Ignition Studies Of Oxy-Syngas/Co2 Mixtures Using Shock Tube For Cleaner Combustion Engines, Samuel Barak
Electronic Theses and Dissertations
In this study, syngas combustion was investigated behind reflected shock waves in order to gain insight into the behavior of ignition delay times and effects of the CO2 dilution. Pressure and light emissions time-histories measurements were taken at a 2 cm axial location away from the end wall. High-speed visualization of the experiments from the end wall was also conducted. Oxy-syngas mixtures that were tested in the shock tube were diluted with CO2 fractions ranging from 60% - 85% by volume. A 10% fuel concentration was consistently used throughout the experiments. This study looked at the effects of changing the …
Explore Contributing Geometric Factors And Built-Environment On Bicycle Activity And Safety At Intersections, Scott Castro
Explore Contributing Geometric Factors And Built-Environment On Bicycle Activity And Safety At Intersections, Scott Castro
Electronic Theses and Dissertations
This study attempts to explore all factors associated with bicycle motor-vehicle crashes at intersections in order to improve bicycle safety and bicycle activity. Factors such as exposure (bicycle and vehicle volumes), existing facilities (bike lanes, sidewalks, shared-use paths), geometric design (# of lanes, speed limit, medians, legs, roadway conditions), and land-use were collected and evaluated using Poisson, Zero-Inflated Poisson, and Negative Binomial models in SAS 9.4 software. Increasing the bicycle travel mode can have positive lasting effects on personal health, the environment, and improve traffic conditions. Deterrents that keep users from riding bicycles more are the lack of facilities and …
Mode-Locked Laser Based On Large Core Yb3+-Doped Fiber, Fei Jia
Mode-Locked Laser Based On Large Core Yb3+-Doped Fiber, Fei Jia
Electronic Theses and Dissertations
The thesis reviews principle of laser cavity and gives a general introduction to modelocked laser (MLL). By using Yb3+-doped fiber as gain medium, passive MLL cavity is developed in experiment, aiming to obtain femtosecond pulses with high pump power from 25W to 35W. The gain medium fiber with 65µm core diameter is cleaved with one flat end and another angled. Pump laser with 976nm wavelength is coupled into Yb3+ -doped fiber to excite signal from 1020nm to 1040nm in the core. 9W is threshold for laser setup. After locking all modes, picosecond pulses are output from laser cavity and coupled …
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations, Joshua Bradford
Fiber Optimization For Operation Beyond Transverse Mode Instability Limitations, Joshua Bradford
Electronic Theses and Dissertations
Transverse Mode Instabilities (TMIs) stand as a fundamental limitation to power and brightness scaling in laser systems based upon optical fiber technologies. This work comprises experimental and theoretical investigations into fiber laser design that should minimize the effects of Stimulated Thermal Rayleigh Scattering. Theoretical discussions and simulations focus on how fiber parameters affect transverse mode coupling. These include core geometry optimization, pump geometry optimization, in addition to the effects of HOM content and losses on the TMI threshold. Experimentally, a high-power laser facility is commissioned with beam quality diagnostics to quantify the thresholds of the onset of modal interferences and …
Applying Machine Learning Techniques To Analyze The Pedestrian And Bicycle Crashes At The Macroscopic Level, Md Sharikur Rahman
Applying Machine Learning Techniques To Analyze The Pedestrian And Bicycle Crashes At The Macroscopic Level, Md Sharikur Rahman
Electronic Theses and Dissertations
This thesis presents different data mining/machine learning techniques to analyze the vulnerable road users' (i.e., pedestrian and bicycle) crashes by developing crash prediction models at macro-level. In this study, we developed data mining approach (i.e., decision tree regression (DTR) models) for both pedestrian and bicycle crash counts. To author knowledge, this is the first application of DTR models in the growing traffic safety literature at macro-level. The empirical analysis is based on the Statewide Traffic Analysis Zones (STAZ) level crash count data for both pedestrian and bicycle from the state of Florida for the year of 2010 to 2012. The …
Monolithically Integrated Wavelength Tunable Laser Diode For Integrated Optic Surface Plasmon Resonance Sensing, Thamer Tabbakh
Monolithically Integrated Wavelength Tunable Laser Diode For Integrated Optic Surface Plasmon Resonance Sensing, Thamer Tabbakh
Electronic Theses and Dissertations
In this work, we demonstrate an InGaAsP multiple quantum well tunable laser diode that amalgamates two gain sections with different bandgap energies. This is achieved using selective area intermixing of the multiple quantum wells, and impurity-free vacancy induced disordering. When different current combination is injected into each section, that leads to a laser wavelength peak whose position depends on the relative magnitudes of the two injected currents. The laser wavelength can be fine-tuned from 1538 nm to 1578 nm with relatively constant output power. The free spectral range FSR of the tunable laser found to be 0.25 nm. This tunable …
Cost And Environmental Impacts Of Leachate Nitrogen/Phosphorus Management Approaches, Alaa Alanezi
Cost And Environmental Impacts Of Leachate Nitrogen/Phosphorus Management Approaches, Alaa Alanezi
Electronic Theses and Dissertations
Landfill leachate is a challenging wastewater to discharge into municipal wastewater treatment plants (WWTPs), the most common approach for leachate management, due to the presence of contaminants that may affect the performance of the treatment plant. Treatment, disposal, and transportation of leachate are expensive and therefore a concern. Currently, sidestream treatment is becoming increasingly common in WWTPs prior to returning the liquid to the plant influent. For this research, a new treatment scheme is introduced combining centrate and leachate to reduce contaminants, recover phosphorous and nitrogen through struvite precipitation, and reduce energy requirements through anaerobic ammonium oxidation (Anammox). By combining …
Flutter Stability Of Shrouded Turbomachinery Cascades With Nonlinear Frictional Damping, Alex Torkaman
Flutter Stability Of Shrouded Turbomachinery Cascades With Nonlinear Frictional Damping, Alex Torkaman
Electronic Theses and Dissertations
Prediction of flutter in shrouded turbomachinery cascades is difficult due to i) coupling of aerodynamic drivers and structural dynamics of the cascade through shrouds, and ii) presence of nonlinear dry friction damping as a result of relative motion between adjacent shrouds. An analytical framework is developed in this dissertation to determine flutter stability of shrouded cascades with consideration of friction damping. This framework is an extension to the well-established energy method, and it includes all contributing factors affecting stability of the cascade such as aerodynamic excitation and the stabilizing effects of dry friction damping caused by nonlinear contact forces between …
The Relationship Between Agile Project Management And Project Success Outcomes, Thomas Bergmann
The Relationship Between Agile Project Management And Project Success Outcomes, Thomas Bergmann
Electronic Theses and Dissertations
Agile project management (APM) has recently emerged as a new approach to managing complex projects. Some experts believe that APM will become the standard project management approach used in the 21st century. However, thus far, the role of agility in project management has not been widely investigated. In the recent past, the concept of agility has mainly been applied to software development projects. The literature on agility is still in its early stages, and further research needs to be conducted in new project management domains. This study is intended to determine the impact of the adoption of APM on project …
Dynamic Hotspot Identification For Limited Access Facilities Using Temporal Traffic Data, Samer Al Amili
Dynamic Hotspot Identification For Limited Access Facilities Using Temporal Traffic Data, Samer Al Amili
Electronic Theses and Dissertations
Crash frequency analysis is the most critical tool to investigate traffic safety problems. Therefore, an accurate crash analysis must be conducted. Since traffic continually fluctuates over time and this effects potential of crash occurrence, shorter time periods and less aggregated traffic factors (shorter intervals than AADT) need to be used. In this dissertation, several methodologies have been conducted to elevate the accuracy of crash prediction. The performance of using less aggregated traffic data in modeling crash frequency was explored for weekdays and weekends. Four-time periods for weekdays and two time periods for weekends, with four intervals (5, 15, 30, and …
Creating A Consistent Oceanic Multi-Decadal Intercalibrated Tmi-Gmi Constellation Data Record, Ruiyao Chen
Creating A Consistent Oceanic Multi-Decadal Intercalibrated Tmi-Gmi Constellation Data Record, Ruiyao Chen
Electronic Theses and Dissertations
The Tropical Rainfall Measuring Mission (TRMM), launched in late November 1997 into a low earth orbit, produced the longest microwave radiometric data time series of 17-plus years from the TRMM Microwave Imager (TMI). The Global Precipitation Measuring (GPM) mission is the follow-on to TRMM, designed to provide data continuity and advance precipitation measurement capabilities. The GPM Microwave Imager (GMI) performs as a brightness temperature (Tb) calibration standard for the intersatellite radiometric calibration (XCAL) for the other constellation members; and before GPM was launched, TMI was the XCAL standard. This dissertation aims at creating a consistent oceanic multi-decadal Tb data record …
Structured Light-Field Focusing 3d Density Measurements Of A Supersonic Cone, Ryonosuke Ozawa
Structured Light-Field Focusing 3d Density Measurements Of A Supersonic Cone, Ryonosuke Ozawa
Electronic Theses and Dissertations
This study describes three-dimensional (3D) quantitative visualization of density field in a supersonic flow around a cone spike. A measurement of the density gradient is conducted within a supersonic wind tunnel facility at the Propulsion and Energy Research Laboratory at the University of Central Florida utilizing Structured Light-Field Focusing Schlieren (SLLF). In conventional schlieren and Shadowgraph techniques, it is widely known that a complicated optical system is needed and yet visualizable area depends on an effective diameter of lenses and mirrors. Unlike these techniques, SLLF is yet one of the same family as schlieren photography, it is capable of non-intrusive …
Biomechanical Models Of Human Upper And Tracheal Airway Functionality, Don Nadun Kuruppumullage
Biomechanical Models Of Human Upper And Tracheal Airway Functionality, Don Nadun Kuruppumullage
Electronic Theses and Dissertations
The respiratory tract, in other words, the airway, is the primary airflow path for several physiological activities such as coughing, breathing, and sneezing. Diseases can impact airway functionality through various means including cancer of the head and neck, Neurological disorders such as Parkinson's disease, and sleep disorders and all of which are considered in this study. In this dissertation, numerical modeling techniques were used to simulate three distinct airway diseases: a weak cough leading to aspiration, upper airway patency in obstructive sleep apnea, and tongue cancer in swallow disorders. The work described in this dissertation, therefore, divided into three biomechanical …