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Vertical Field Switching Blue Phase Liquid Crystals For Field Sequential Color Displays, Hui-Chuan Cheng
Vertical Field Switching Blue Phase Liquid Crystals For Field Sequential Color Displays, Hui-Chuan Cheng
Electronic Theses and Dissertations
Low power consumption is a critical requirement for all liquid crystal display (LCD) devices. A field sequential color (FSC) LCD was proposed by using red (R), green (G) and blue (B) LEDs and removing the lossy component of color filters which only transmits ~30% of the incoming white light. Without color filters, FSC LCDs exhibit a ~3X higher optical efficiency and 3X higher resolution density as compared to the conventional color filters-based LCDs. However, color breakup (CBU) is a most disturbing defect that degrades the image quality in FSC displays. CBU can be observed in stationary or moving images. It …
High Performance Low Voltage Power Mosfet For High-Frequency Synchronous Buck Converters, Boyi Yang
High Performance Low Voltage Power Mosfet For High-Frequency Synchronous Buck Converters, Boyi Yang
Electronic Theses and Dissertations
Power management solutions such as voltage regulator (VR) mandate DC-DC converters with high power density, high switching frequency and high efficiency to meet the needs of future computers and telecom equipment. The trend towards DC-DC converters with higher switching frequency presents significant challenges to power MOSFET technology. Optimization of the MOSFETs plays an important role in improving low-voltage DC-DC converter performance. This dissertation focuses on developing and optimizing high performance low voltage power MOSFETs for high frequency applications. With an inherently large gate charge, the trench MOSFET suffers significant switching power losses and cannot continue to provide sufficient performance in …
Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li
Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li
Electronic Theses and Dissertations
Non-protein-coding RNAs play critical regulatory roles in cellular life. Many ncRNAs fold into specific structures in order to perform their biological functions. Some of the RNAs, such as riboswitches, can even fold into alternative structural conformations in order to participate in different biological processes. In addition, these RNAs can transit dynamically between different functional structures along folding pathways on their energy landscapes. These alternative functional structures are usually energetically favored and are stable in their local energy landscapes. Moreover, conformational transitions between any pair of alternate structures usually involve high energy barriers, such that RNAs can become kinetically trapped by …
Systems Analysis For Urban Water Infrastructure Expansion With Global Change Impact Under Uncertainties, Cheng Qi
Electronic Theses and Dissertations
Over the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long-term expansion planning to reduce the risk from global change impact with respect to greenhouse gas (GHG) emissions, economic boom and recession, as well as water demand variation associated with population growth and migration. …
Evaporation, Precipitation Dynamics And Instability Of Acoustically Levitated Functional Droplets, Abhishek Saha
Evaporation, Precipitation Dynamics And Instability Of Acoustically Levitated Functional Droplets, Abhishek Saha
Electronic Theses and Dissertations
Evaporation of pure and binary liquid droplets is of interest in thermal sprays and spray drying of food, ceramics and pharmaceutical products. Understanding the rate of heat and mass transfer in any drying process is important not only to enhance evaporation rate or vapor-gas mixing, but also to predict and control the final morphology and microstructure of the precipitates. Acoustic levitation is an alternative method to study micron-sized droplets without wall effects, which eliminates chemical and thermal contamination with surfaces. This work uses an ultrasonic levitation technique to investigate the vaporization dynamics under radiative heating, with focus on evaporation characteristics, …
Bst-Inspired Smart Flexible Electronics, Ya Shen
Bst-Inspired Smart Flexible Electronics, Ya Shen
Electronic Theses and Dissertations
The advances in modern communication systems have brought about devices with more functionality, better performance, smaller size, lighter weight and lower cost. Meanwhile, the requirement for newer devices has become more demanding than ever. Tunability and flexibility are both long-desired features. Tunable devices are ‘smart’ in the sense that they can adapt to the dynamic environment or varying user demand as well as correct the minor deviations due to manufacturing fluctuations, therefore making it possible to reduce system complexity and overall cost. It is also desired that electronics be flexible to provide conformability and portability. Previously, tunable devices on flexible …
Multi-Level Safety Performance Functions For High Speed Facilities, Mohamed Ahmed
Multi-Level Safety Performance Functions For High Speed Facilities, Mohamed Ahmed
Electronic Theses and Dissertations
High speed facilities are considered the backbone of any successful transportation system; Interstates, freeways, and expressways carry the majority of daily trips on the transportation network. Although these types of roads are relatively considered the safest among other types of roads, they still experience many crashes, many of which are severe, which not only affect human lives but also can have tremendous economical and social impacts. These facts signify the necessity of enhancing the safety of these high speed facilities to ensure better and efficient operation. Safety problems could be assessed through several approaches that can help in mitigating the …
Towards Scalable Nanomanufacturing: Modeling The Interaction Of Charged Droplets From Electrospray Using Gpu, Weiwei Yang
Towards Scalable Nanomanufacturing: Modeling The Interaction Of Charged Droplets From Electrospray Using Gpu, Weiwei Yang
Electronic Theses and Dissertations
Electrospray is an atomization method subject to intense study recently due to its monodispersity and the wide size range of droplets it can produce, from nanometers to hundreds of micrometers. This thesis focuses on the numerical and theoretical modeling of the interaction of charged droplets from the single and multiplexed electrospray. We studied two typical scenarios: large area film depositions using multiplexed electrospray and fine pattern printings assisted by linear electrostatic quadrupole focusing. Due to the high computation power requirement in the unsteady n-body problem, graphical processing unit (GPU) which delivers 10 Tera flops in computation power is used to …
A Retrospective Analysis And Field Study Of Nanotechnology Related Ergonomic Risk In Industries Utilizing Nanomaterials, Wanda Greaves-Holmes
A Retrospective Analysis And Field Study Of Nanotechnology Related Ergonomic Risk In Industries Utilizing Nanomaterials, Wanda Greaves-Holmes
Electronic Theses and Dissertations
The National Science Foundation estimates that two million skilled nanotechnology workers will be needed world wide by 2015 – one million of them in the United States (2001). In the absence of scientific clarity about the potential health effects of occupational exposure to nanoparticles, guidance in decision making about hazards, risk, and controls takes on new importance. Currently, guiding principles on personal protective equipment for workers who come in contact with nanomaterials have not been standardized universally. Utilizing the NASATLX, this dissertation investigates the adequacy and shortcomings of research efforts that seek to determine whether or not occupational exposure to …
Design And Characterization Of High Temperature Packaging For Wide-Bandgap Semiconductor Devices, Brian Grummel
Design And Characterization Of High Temperature Packaging For Wide-Bandgap Semiconductor Devices, Brian Grummel
Electronic Theses and Dissertations
Advances in wide-bandgap semiconductor devices have increased the allowable operating temperature of power electronic systems. High-temperature devices can benefit applications such as renewable energy, electric vehicles, and space-based power electronics that currently require bulky cooling systems for silicon power devices. Cooling systems can typically be reduced in size or removed by adopting wide-bandgap semiconductor devices, such as silicon carbide. However, to do this, semiconductor device packaging with high reliability at high temperatures is necessary. Transient liquid phase (TLP) die-attach has shown in literature to be a promising bonding technique for this packaging need. In this work TLP has been comprehensively …
Resilience Of Bridges Following Aftershocks, Diego Francisco Espinosa
Resilience Of Bridges Following Aftershocks, Diego Francisco Espinosa
Electronic Theses and Dissertations
The ability to predict the reduction in capacity of a structure after an earthquake is vital in the process of assessing a structure after a main-shock or an after-shock. Main-shocks are normally followed by a few aftershocks in a short period of time. Researchers in the past have focused for the most part on the effects of main-shocks on buildings. Very little research has been performed on the ability to predict the reduction in capacity of bridges in aftershocks. This thesis focuses on providing a way of assessing the reduction in capacity for main-shocks as compared to aftershocks and the …
Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho
Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho
Electronic Theses and Dissertations
Non-reciprocal wave transmission is a phenomenon witnessed in certain photonic devices when the wave propagation dynamics through the device along one direction differs greatly from the dynamics along the counter-propagating direction. Specifically, it refers to significant power transfer occurring in one direction, and greatly reduced power transfer in the opposite direction. The resulting effect is to isolate the directionality of wave propagation, allowing transmission to occur along one direction only. Given the popularity of photonic integrated circuits (PIC), in which all the optical components are fabricated on the same chip so that the entire optical system can be made more …
Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe
Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe
Electronic Theses and Dissertations
Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …
Turbidity Removal Efficiency And Toxicity Issues Associated With The Chitosan-Based Dual Bio-Polymer Systems, Rylee Hernandez
Turbidity Removal Efficiency And Toxicity Issues Associated With The Chitosan-Based Dual Bio-Polymer Systems, Rylee Hernandez
Electronic Theses and Dissertations
Stormwater runoff can be a great concern in the State of Florida due to the impact the quality of the runoff water can have on the natural water bodies. Stormwater runoff can carry pollutants and sediments which can cause both physical and biological risks in an aquatic ecosystem such as a lake, river, or pond. Polymers, namely the chitosan-based dual polymer system, can be used remove the sediment from this runoff to ensure the safety of the state’s water bodies. Three soils are used in this testing: AASTO soil classifications A-3(sandy soil) and A-2- 4 (silty-sand), and a soil with …
Evaluation Of Biosorption Activated Media Under Roadside Swales For Stormwater Quality Improvement And Harvesting, Andrew Charles Hood
Evaluation Of Biosorption Activated Media Under Roadside Swales For Stormwater Quality Improvement And Harvesting, Andrew Charles Hood
Electronic Theses and Dissertations
Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. This project develops a bio-detention treatment and harvesting system that is incorporated into roadside swales. The bio-detention system uses Bold & Gold™, a type of biosorption activated media (BAM), to remove nutrients from simulated highway runoff and then store the water in underground vaults for infiltration, controlled discharge, and/or irrigation and other non-potable applications. In order to design a bio-detention system, media characteristics and media/water quality relationships are required. Media characteristics determined through testing include: specific gravity, permeability, infiltration, maximum dry density, moisture content of …
Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek
Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek
Electronic Theses and Dissertations
Forecasts of short term volcanic activity are generated using an event tree process that is driven by a set of empirical statistical models derived through logistic regression. Each of the logistic models are constructed from a sparse and geographically diverse dataset that was assembled from a collection of historic volcanic unrest episodes. The dataset consists of monitoring measurements (e.g. seismic), source modeling results, and historic eruption information. Incorporating this data into a single set of models provides a simple mechanism for simultaneously accounting for the geophysical changes occurring within the volcano and the historic behavior of analog volcanoes. A bootstrapping …
Numerical Study On Reinforcement Mechanism Of Copper/Carbon Nanotubes Composite, Xiang Long
Numerical Study On Reinforcement Mechanism Of Copper/Carbon Nanotubes Composite, Xiang Long
Electronic Theses and Dissertations
Because of its high stiffness, carbon nanotubes (CNTs) are considered as one of the widely used reinforcement materials in the metal matrix composites. In this thesis, finite element (FE) models were built in Ls-Dyna3D to simulate Copper/CNTs composite deformation and fracture, and to explore CNTs reinforcement mechanisms. Several possible mechanisms were discussed. Deformation and failure of Cu/CNT composites were studied numerically using unit cell FE models, which consist of both metal matrix and CNTs. The simulation results have been verified by existing experiment data reported by Chen’s group. The matrix material was modeled as elasto-plastic ductile solids. The CNTs material …
State (Hydrodynamics) Identification In The Lower St. Johns River Using The Ensemble Kalman Filter, Hitoshi Tamura
State (Hydrodynamics) Identification In The Lower St. Johns River Using The Ensemble Kalman Filter, Hitoshi Tamura
Electronic Theses and Dissertations
This thesis presents a method, Ensemble Kalman Filter (EnKF), applied to a highresolution, shallow water equations model (DG ADCIRC-2DDI) of the Lower St. Johns River with observation data at four gauging stations. EnKF, a sequential data assimilation method for non-linear problems, is developed for tidal flow simulation for estimation of state variables, i.e., water levels and depth-integrated currents for overland unstructured finite element meshes. The shallow water equations model is combined with observation data, which provides the basis of the EnKF applications. In this thesis, EnKF is incorporated into DG ADCIRC-2DDI code to estimate the state variables. Upon its development, …
Construction And Demolition Debris Recovery And Recycling In Orange County, Fl, Michael Stephen Toth Ii
Construction And Demolition Debris Recovery And Recycling In Orange County, Fl, Michael Stephen Toth Ii
Electronic Theses and Dissertations
In 2008, the State of Florida established a recycling goal of 75% to be achieved by 2020. In response to the Florida goal Orange County (OC), Florida has made the development and implementation of an efficient strategy for landfill diversion of its solid waste a top priority. The Florida Department of Environmental Protection (FDEP) estimated that 23 % of municipal solid waste was generated by construction and demolition (C&D) activities in 2009, with only 30 percent of C&D debris being recycled. Therefore, OC decided to create a solid waste integrated resource plan (SWIRP) initially focused on the recovery and recycling …
Synchronous Communication System For Saw Sensors Interrogation, Maxim Troshin
Synchronous Communication System For Saw Sensors Interrogation, Maxim Troshin
Electronic Theses and Dissertations
During past two decades a variety of SAW based wireless sensors were invented and research is still in progress. As different frequencies, varied bandwidths, coding techniques and constantly changing post processing algorithms are being implemented, there is a constant need for a universal and adjustable synchronous communication system able to interrogate new generations of SAW sensors. This thesis presents the design of a multiple FPGA based communication system with an operational frequency range of 450MHz-2.2GHz capable of producing user programmed modulated signal. The synchronous receiver is designed to have interchangeable chip, replacement of which would allow adjustment of the receiver’s …
Electromagnetic Environment In Payload Fairing Cavities, Dawn Trout
Electromagnetic Environment In Payload Fairing Cavities, Dawn Trout
Electronic Theses and Dissertations
An accurate determination of a spacecraft’s radio frequency electromagnetic field environment during launch and flight is critical for mission success. Typical fairing structures consist of a parabolic nose and a cylindrical core with diameters of 1 to 5 meters resulting in electrically large dimensions for typical operational sources at S, C and X band where the free space wavelength varies from 0.15 m to 0.03 m. These electrically large size and complex structures at present have internal fairing electromagnetic field evaluation that is limited to general approximation methods and some test data. Though many of today’s computational electromagnetic tools can …
Hfs Plus File System Exposition And Forensics, Scott Ware
Hfs Plus File System Exposition And Forensics, Scott Ware
Electronic Theses and Dissertations
The Macintosh Hierarchical File System Plus, HFS +, or as it is commonly referred to as the Mac Operating System, OS, Extended, was introduced in 1998 with Mac OS X 8.1. HFS+ is an update to HFS, Mac OS Standard format that offers more efficient use of disk space, implements international friendly file names, future support for named forks, and facilitates booting on non-Mac OS operating systems through different partition schemes. The HFS+ file system is efficient, yet, complex. It makes use of B-trees to implement key data structures for maintaining meta-data about folders, files, and data. The implementation of …
Fire Retardant Polymer Nanocomposites: Materials Design And Thermal Degradation Modeling, Jinfeng Zhuge
Fire Retardant Polymer Nanocomposites: Materials Design And Thermal Degradation Modeling, Jinfeng Zhuge
Electronic Theses and Dissertations
Compared to conventional materials, polymer matrix composites (PMCs) have a number of attractive properties, including light weight, easiness of installation, potential to lower system-level cost, high overall durability, and less susceptibility to environmental deterioration. However, PMCs are vulnerable to fire such that they degrade, decompose, and sometimes yield toxic gases at high temperature. The degradation and decomposition of composites lead to loss in mass, resulting in loss in mechanical strength. This research aims to improve the structural integrity of the PMCs under fire conditions by designing and optimizing a fire retardant nanopaper coating, and to fundamentally understand the thermal response …
A Framework For Process Data Collection, Analysis, And Visualization In Construction Projects, Reza Akhavian
A Framework For Process Data Collection, Analysis, And Visualization In Construction Projects, Reza Akhavian
Electronic Theses and Dissertations
Automated data collection, simulation and visualization can substantially enhance the process of designing, analysis, planning, and control of many engineering processes. In particular, managing processes that are dynamic in nature can significantly benefit from such techniques. Construction projects are good examples of such processes where a variety of equipment and resources constantly interact inside an evolving environment. Management of such settings requires a platform capable of providing decision-makers with updated information about the status of project entities and assisting site personnel making critical decisions under uncertainty. To this end, the current practice of using historical data or expert judgments as …
Numerical Simulation Of Electrolyte-Supported Planar Button Solid Oxide Fuel Cell, Amjad Aman
Numerical Simulation Of Electrolyte-Supported Planar Button Solid Oxide Fuel Cell, Amjad Aman
Electronic Theses and Dissertations
Solid Oxide Fuel Cells are fuel cells that operate at high temperatures usually in the range of 600oC to 1000oC and employ solid ceramics as the electrolyte. In Solid Oxide Fuel Cells oxygen ions (O2- ) are the ionic charge carriers. Solid Oxide Fuel Cells are known for their higher electrical efficiency of about 50-60% [1] compared to other types of fuel cells and are considered very suitable in stationary power generation applications. It is very important to study the effects of different parameters on the performance of Solid Oxide Fuel Cells and for this purpose the experimental or numerical …
Critical Success Factors For Evolutionary Acquisition Implementation, Brig J. Bjorn
Critical Success Factors For Evolutionary Acquisition Implementation, Brig J. Bjorn
Electronic Theses and Dissertations
Due to extensive challenges to the efficient development and fielding of operationally effective and affordable weapon systems, the U.S. employs a complex management framework to govern defense acquisition programs. The Department of Defense and Congress recently modified this process to improve the levels of knowledge available at key decision points in order to reduce lifecycle cost, schedule, and technical risk to programs. This exploratory research study employed multiple methods to examine the impact of systems engineering reviews, competitive prototyping, and the application of a Modular Open Systems Approach on knowledge and risk prior to funding system implementation and production. In-depth …
A Bench Top Study Of The Optimization Of Lvad Cannula Implantation To Reduce Risk Of Cerebral Embolism, William D. Clark
A Bench Top Study Of The Optimization Of Lvad Cannula Implantation To Reduce Risk Of Cerebral Embolism, William D. Clark
Electronic Theses and Dissertations
Physical bench top experiments are performed to validate and complement ongoing computational fluid dynamics (CFD) analyses of ventricular assist device (VAD) circulation. VADs are used in patients whose hearts do not function to their maximum potential due advanced stages of heart disease and, consequently, are unable to adequately supply blood to the systemic circulation. VADs are commonly utilized as a bridge-to-transplantation, meaning that they are implanted in patients while waiting for a heart transplant. In such cases of long term utilization of VADs, it has been reported in the literatures that thrombo-embolic cerebral events occur in 14-47% of patients over …
Phase Field Modeling Of Thermotransport In Multicomponent Systems, Joshua Bush
Phase Field Modeling Of Thermotransport In Multicomponent Systems, Joshua Bush
Electronic Theses and Dissertations
Nuclear and gas turbine power plants, computer chips, and other devices and industries are running hotter than ever for longer than ever. With no apparent end to the trend, the potential arises for a phenomenon known as thermotransport to cause undesirable changes in these high temperature materials. The diffuse-interface method known as the phase-field model is a useful tool in the simulation and prediction of thermotransport driven microstructure evolution in materials. The objective of this work is to develop a phase-field model using practical and empirical properties of thermodynamics and kinetics for simulating the interdiffusion behavior and microstructural evolution of …
Performance Of Mechanical And Non-Mechanical Connections To Gfrp Components, Nnadozie N. Dike
Performance Of Mechanical And Non-Mechanical Connections To Gfrp Components, Nnadozie N. Dike
Electronic Theses and Dissertations
There are presently many solutions to dealing with aging or deteriorated structures. Depending on the state of the structure, it may need to be completely over-hauled, demolished and replaced, or only specific components may need rehabilitation. In the case of bridges, rehabilitation and maintenance of the decks are critical needs for infrastructure management. Viable rehabilitation options include replacement of decks with aluminum extrusions, hybrid composite and sandwich systems, precast reinforced concrete systems, or the use of pultruded fiber-reinforced polymer (FRP) shapes. Previous research using pultruded glass fiber-reinforced polymer (GFRP) decks, focused on behaviour under various strength and serviceability loading conditions. …
Effects Of Allotropic Transformations On Interdiffusion Behavior In Binary Systems, Ashley Elizabeth Ewh
Effects Of Allotropic Transformations On Interdiffusion Behavior In Binary Systems, Ashley Elizabeth Ewh
Electronic Theses and Dissertations
Diffusion plays a significant role in most materials systems by controlling microstructural development. Consequently, the overall properties of a material can be largely dependent upon diffusion. This study investigated the interdiffusion behavior of three binary systems, namely, Mo-Zr, Fe-Mo, and Fe-Zr. The main interest in these particular metals is for application in nuclear fuel assemblies. Nuclear fuel plates generally consist of two main components which are the fuel and the cladding. Due to diffusional interactions that can occur between these two components, a third is sometimes added between the fuel and cladding to serve as a diffusion barrier layer. Fe, …