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Articles 1381 - 1410 of 4566

Full-Text Articles in Engineering

Evaluation Of Real World Toll Plazas Using Driving Simulation, Kali Carroll Jan 2016

Evaluation Of Real World Toll Plazas Using Driving Simulation, Kali Carroll

Electronic Theses and Dissertations

Toll plazas are becoming an essential part of the highway system, especially within the state of Florida. Many crashes reported on highways occur at toll plazas. A primary reason for many vehicle collisions happening at these facilities is the fact that each toll plaza agency has different design, signage and marking criteria. This, in turn, causes driver confusion and possible last minute weaving maneuvers. Even though the varying design of toll plazas is a clear highway safety factor, research in the field is very limited but expanding. This study focuses on one toll plaza, in particular the Dean Mainline Toll …

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A Predictive Model To Identify Caregivers At Risk Of Musculoskeletal Disorders, Abdulelah Ali Jan 2016

A Predictive Model To Identify Caregivers At Risk Of Musculoskeletal Disorders, Abdulelah Ali

Electronic Theses and Dissertations

Healthcare systems face several challenges due to the aging workforce, recruitment shortages, increasing patient acuteness, and increasing patient size and weight. The most costly, leading, and prevalent problem in the healthcare industry and nursing professions is work-related Musculoskeletal Disorders (MSDs). MSDs are common among caregivers because of the nature of their work, which requires repetitive heavy physical activity. The development of MSDs among caregivers negatively impacts the quality of care, and incurs high costs such as worker compensation, days away from work, turnover, rehabilitation, and lower productivity. Therefore, it is essential to determine the factors that contribute to musculoskeletal disorder …

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Techniques For Automated Parameter Estimation In Computational Models Of Probabilistic Systems, Faraz Hussain Jan 2016

Techniques For Automated Parameter Estimation In Computational Models Of Probabilistic Systems, Faraz Hussain

Electronic Theses and Dissertations

The main contribution of this dissertation is the design of two new algorithms for automatically synthesizing values of numerical parameters of computational models of complex stochastic systems such that the resultant model meets user-specified behavioral specifications. These algorithms are designed to operate on probabilistic systems – systems that, in general, behave differently under identical conditions. The algorithms work using an approach that combines formal verification and mathematical optimization to explore a model's parameter space. The problem of determining whether a model instantiated with a given set of parameter values satisfies the desired specification is first defined using formal verification terminology, …

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Impact Of The Longer Change And Clearance Intervals On Signalized Intersections And Corridors, Mohammed Alfawzan Jan 2016

Impact Of The Longer Change And Clearance Intervals On Signalized Intersections And Corridors, Mohammed Alfawzan

Electronic Theses and Dissertations

Evaluating the impact of longer change and clearance intervals on signalized intersections and corridors is the main goal of this study. In fact, the Florida department of Transportation (FDOT) has adopted a new signal retiming effort in a number of signalized intersections along several corridors. The Orange County started implementing the new signal timing from December, 2013 and completed it in June, 2015. The other objective of this new signal timing is to minimize the red light running rate. This study is dedicated to investigate the signal retiming effort adopted by the FDOT and how the new signal timing might …

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Model Selection Via Racing, Tiantian Zhang Jan 2016

Model Selection Via Racing, Tiantian Zhang

Electronic Theses and Dissertations

Model Selection (MS) is an important aspect of machine learning, as necessitated by the No Free Lunch theorem. Briefly speaking, the task of MS is to identify a subset of models that are optimal in terms of pre-selected optimization criteria. There are many practical applications of MS, such as model parameter tuning, personalized recommendations, A/B testing, etc. Lately, some MS research has focused on trading off exactness of the optimization with somewhat alleviating the computational burden entailed. Recent attempts along this line include metaheuristics optimization, local search-based approaches, sequential model-based methods, portfolio algorithm approaches, and multi-armed bandits. Racing Algorithms (RAs) …

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Non-Dispersive Infrared (Ndir) Gas Sensor Utilizing Light-Emitting-Diodes Suitable For Applications Demanding Low-Power And Lightweight Instruments, Kyle Thurmond Jan 2016

Non-Dispersive Infrared (Ndir) Gas Sensor Utilizing Light-Emitting-Diodes Suitable For Applications Demanding Low-Power And Lightweight Instruments, Kyle Thurmond

Electronic Theses and Dissertations

Gas sensors that are low-power, light-weight, and rugged, while also remaining low-cost, have considerable appeal to areas from automotive to space flight. There are increasing demands for higher efficient vehicles with lower emissions in order meet regulations that are meant to mitigate or lessen the effects of climate change. An affordable, fast response sensor that can measure transient carbon monoxide (CO) and carbon dioxide (CO2) has broad application which can lead to more efficient, fuel flexible engines and regulations of harmful emissions. With compact, economical, low-power sensors that are able to continually monitor gases that are characteristic of burning materials, …

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Design And Characterization Of System Level Electrostatic Discharge (Esd) Protection Solutions, Yunfeng Xi Jan 2016

Design And Characterization Of System Level Electrostatic Discharge (Esd) Protection Solutions, Yunfeng Xi

Electronic Theses and Dissertations

Electrostatic Discharges (ESD) are one of the main reliability threats in modern electronics. Design, implementation, and characterization of ESD and transient protection of these modern electronics are increasingly challenging due to the process, packaging and cost constraints. Growing communication between ‘objects’ to be sensed and controlled remotely is creating opportunities for greater integration with computer systems, resulting in improved efficiency, accuracy and economic benefits across existing and emerging network infrastructures. This tendency is driving an expansion in data communication as well as industrial applications environment. To keep up with the interconnectivity expansion, the industry requires new devices to support more …

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Transcriptional And Post-Transcriptional Regulation Of Gene Expression, Jun Ding Jan 2016

Transcriptional And Post-Transcriptional Regulation Of Gene Expression, Jun Ding

Electronic Theses and Dissertations

Regulation of gene expression includes a variety of mechanisms to increase or decrease specific gene products. Gene expression can be regulated at any stage from transcription to post-transcription and it's essential to almost all living organisms, as it increases the versatility and adaptability by allowing the cell to express the needed proteins. In this dissertation, we comprehensively studied the gene regulation from both transcriptional and post-transcriptional points of view. Transcriptional regulation is by which cells regulate the transcription from DNA to RNA, thereby directing gene activity. Transcriptional factors (TFs) play a very important role in transcriptional regulation and they are …

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The Effect Of Baldrige Performance Excellence Program On Organization's Innovation/Dynamic Capabilities, Mohammed Alomairy Jan 2016

The Effect Of Baldrige Performance Excellence Program On Organization's Innovation/Dynamic Capabilities, Mohammed Alomairy

Electronic Theses and Dissertations

This dissertation investigated the effect of Baldrige performance excellence program on organization's innovation/dynamic capabilities improvement. According to the literature, there is little or no practical method for building dynamic/innovation capabilities within organizations. The study hypothesizes that Baldrige performance excellence program helps organizations to systematically develop the required dynamic/innovation capabilities for innovation. Twenty-four organizations that had implemented Baldrige program over the past five years participated in this research study. Two types of data were measured/collected from these organizations; Performance excellence data and Innovation capabilities data. To avoid bias in the data collection, the two data were measured and collected at different …

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A New Six Sigma Implementation Approach For Power Generation Gas Turbines Repair Process Development, Somesh Ghunakikar Jan 2016

A New Six Sigma Implementation Approach For Power Generation Gas Turbines Repair Process Development, Somesh Ghunakikar

Electronic Theses and Dissertations

Power Generation gas turbines used for heavy duty application mainly constitutes three modules; compressor, combustion and turbine. Typically, all these parts are designed by OEM companies for specific number of hours and cycles (also known as starts) before they become dysfunctional. In addition, Gas Turbine (GT) also have intended repair interval depending upon the type of part application and anticipated damages during service operation. Thus, GT parts need inspections and repair (overhaul) after certain operating hours in order to recondition them so that they can be fit for reoperation to produce power. In this dissertation, a unique six sigma DFSS …

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High Temperature Shock Tube Ignition Studies Of Co2 Diluted Mixtures, Owen Pryor Jan 2016

High Temperature Shock Tube Ignition Studies Of Co2 Diluted Mixtures, Owen Pryor

Electronic Theses and Dissertations

Energy demand is expected to grow by 20% over the next 10 years. In order to account for this increase in energy consumption new and novel combustion techniques are required to mitigate the effects of pollution and fossil fuel dependency. Oxy-fuel combustion in supercritical carbon dioxide (sCO2) cycles can increase plant efficiencies up to 52% and reduce pollutants such as NOX and CO2 by 99%. Supercritical engine cycles have demonstrated electricity costs of $121/MWh, which is competitive in comparison to conventional coal ($95.60/MWh) and natural gas power plants ($128.4/MWe). This increase in efficiency is mainly driven by the near-liquid density …

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Interdiffusion, Crystallography And Mechanical Properties Of Nickel Manganese Gallium Alloys, Le Zhou Jan 2016

Interdiffusion, Crystallography And Mechanical Properties Of Nickel Manganese Gallium Alloys, Le Zhou

Electronic Theses and Dissertations

NiMnGa Heusler alloys, functioning as either ferromagnetic shape memory alloys or mangetocaloric materials, have both practical applications and fundamental research value. The functional properties of NiMnGa alloys are closely related to the martensitic transformation from high temperature austenitic phase to low temperature martensitic phase. Alloys can be used for room temperature or high temperature applications, depending on the martensitic transformation temperature, which is compositional sensitive. The microstructure and crystallography of the martensites can be very complex but are crucial to the optimization of the material performance. In this study, for the first time, a combinatorial study by combining solid-to-solid diffusion …

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Study On Anisotropic Plasticity And Fracture Of Lightweight Metal Sheets, Yueqian Jia Jan 2016

Study On Anisotropic Plasticity And Fracture Of Lightweight Metal Sheets, Yueqian Jia

Electronic Theses and Dissertations

How to reduce weight and increase fuel efficiency is a critical challenge in transportation industries. One way to resolve the problem is to adopting lightweight alloys (i.e. advanced high strength steel, aluminum alloys, or magnesium alloy) in structure designs and manufacturing. Fully understanding the mechanical properties of these materials is a key step. In order to fully characterize the plasticity and fracture of magnesium AZ31B-H24 sheets, a set of mechanical experiments (170 in total) were performed under both monotonic and non-proportional loading conditions, including monotonic uniaxial tension, notch tension, in-plane uniaxial compression, wide compression (or called biaxial compression), plane strain …

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Improving Efficiency In Deep Learning For Large Scale Visual Recognition, Baoyuan Liu Jan 2016

Improving Efficiency In Deep Learning For Large Scale Visual Recognition, Baoyuan Liu

Electronic Theses and Dissertations

The emerging recent large scale visual recognition methods, and in particular the deep Convolutional Neural Networks (CNN), are promising to revolutionize many computer vision based artificial intelligent applications, such as autonomous driving and online image retrieval systems. One of the main challenges in large scale visual recognition is the complexity of the corresponding algorithms. This is further exacerbated by the fact that in most real-world scenarios they need to run in real time and on platforms that have limited computational resources. This dissertation focuses on improving the efficiency of such large scale visual recognition algorithms from several perspectives. First, to …

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Towards Energy-Efficient And Reliable Computing: From Highly-Scaled Cmos Devices To Resistive Memories, Soheil Salehi Mobarakeh Jan 2016

Towards Energy-Efficient And Reliable Computing: From Highly-Scaled Cmos Devices To Resistive Memories, Soheil Salehi Mobarakeh

Electronic Theses and Dissertations

The continuous increase in transistor density based on Moore's Law has led us to highly scaled Complementary Metal-Oxide Semiconductor (CMOS) technologies. These transistor-based process technologies offer improved density as well as a reduction in nominal supply voltage. An analysis regarding different aspects of 45nm and 15nm technologies, such as power consumption and cell area to compare these two technologies is proposed on an IEEE 754 Single Precision Floating-Point Unit implementation. Based on the results, using the 15nm technology offers 4-times less energy and 3-fold smaller footprint. New challenges also arise, such as relative proportion of leakage power in standby mode …

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Characterization Of Slm-Manufactured Turbine Blade Microfeatures From Superalloy Powders, Brandon Ealy Jan 2016

Characterization Of Slm-Manufactured Turbine Blade Microfeatures From Superalloy Powders, Brandon Ealy

Electronic Theses and Dissertations

The limits of gas turbine technology are heavily influenced by materials and manufacturing capabilities. Inconel remains the material of choice for most hot gas path (HGP) components in gas turbines, however recent increases in turbine inlet temperature (TIT) are associated with the development of advanced convective cooling methods and ceramic thermal barrier coatings. Increasing cycle efficiency and cycle specific work are the primary drivers for increasing TIT. Lately, incremental performance gains responsible for increasing the allowable TIT have been made mainly through innovations in cooling technology, specifically convective cooling schemes. An emerging manufacturing technology may further facilitate the increase of …

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Live Versus Virtual: Cost Benefit Analysis For Applying Simulation Towards Army Aviator Flight Minimums, Dylan Morelle Jan 2016

Live Versus Virtual: Cost Benefit Analysis For Applying Simulation Towards Army Aviator Flight Minimums, Dylan Morelle

Electronic Theses and Dissertations

The Longbow Crew Trainer (LCT) is a cost effective, safe alternative to live training in the AH-64D/E Apache helicopter. Current Army doctrine and regulations have provisions for the limited use of simulator in lieu of aircraft hours toward semiannual minimum flight hour requirements. With the defense budget in decline, the Army must find innovative, cost effective methods to conduct realistic, relevant training to sustain proficiency in their warfighting capabilities. The LCT fully replicates the cockpit environment through training scenarios for requisite crew tasks and missions in a realistic, modular, and transportable solution. An attack helicopter crew can safely train in …

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Catalytically Enhanced Heterogeneous Combustion Of Methane, Anthony Terracciano Jan 2016

Catalytically Enhanced Heterogeneous Combustion Of Methane, Anthony Terracciano

Electronic Theses and Dissertations

Heterogeneous combustion is an advanced internal combustion technique, which enables heat recuperation within the flame by utilizing a highly porous ceramic media as a regenerator. Heat released within the gas phase convectively transfers to the solid media. This heat within the solid media then travels towards the inlet, enabling reactant preheating. Such heat redistribution enables stable burning of both ultra-lean fuel/air mixtures, forming a more diffuse flame through the combustion chamber, and results in reduced pollutant formation. To further enhance heterogeneous combustion, the ceramic media can be coated with catalytically active materials, which facilitates surface based chemical reactions that could …

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Approximated Control Affine Dynamics Mode For An Agricultural Field Robot Considering Wheel Terrain Interaction, Pablo Menendez-Aponte Jan 2016

Approximated Control Affine Dynamics Mode For An Agricultural Field Robot Considering Wheel Terrain Interaction, Pablo Menendez-Aponte

Electronic Theses and Dissertations

As populations and the demand for higher crop yields grow, so to does the need for efficient agricultural wheeled mobile robots. To achieve precise navigation through a field it is desirable that the control system is designed based on an accurate dynamic model. In this paper a control affine model for a custom designed skid-steer differential drive wheeled mobile robot is found. The Terramechanic wheel terrain interaction is adopted and modified to consider wheels with a torus geometry. Varying slip ratios and slip angles are considered in the terrain reaction forces, which is curve-fitted using a nonlinear least squares approach …

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Determining The Feasibility Of Using Micro Simulation To Asses Safety Of Pedestrian Crossings, Jenner Darius Jan 2016

Determining The Feasibility Of Using Micro Simulation To Asses Safety Of Pedestrian Crossings, Jenner Darius

Electronic Theses and Dissertations

For the past several decades, pedestrian safety has been an oncoming issue that has thrown the area of transportation engineering into a frenzy. Pedestrian safety has become predominantly one of the leading causes of fatalities in traffic accidents. Florida has been reported as one of the leading states in pedestrian fatalities with 2.56 fatality rate per 100,000 population and about 20 percent of all traffic fatalities in the state of Florida. Nonetheless, as research is being done and hypotheses are being calibrated and produced, there has to be a way of measuring and determining the number of pedestrian-to-vehicle conflicts without …

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The Effect Of Building Information Modeling On Design And Construction Industry, Yahya Alassaf Jan 2016

The Effect Of Building Information Modeling On Design And Construction Industry, Yahya Alassaf

Electronic Theses and Dissertations

Construction industry's evolution is, historically, in the lowest level, if compared to other industries, such as auto manufacturing. Construction is a multidisciplinary industry, considering that designers, contractors, and owners are all involved in the same project, each one seeking their own interests. The complex environment surrounding design and construction makes the decision-makers hesitate about adopting new methodology. Building Information Modeling (BIM) is a new method and technology, which can improve both the design and the construction processes. The adoption of BIM is increasing significantly over the last years, and its effects can be seen on real life projects. In order …

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Investigation Of Real Gas Effects On Centrifugal Compressor Analytical Methods For Supercritical Co2 Power Cycles, Lauren Blanchette Jan 2016

Investigation Of Real Gas Effects On Centrifugal Compressor Analytical Methods For Supercritical Co2 Power Cycles, Lauren Blanchette

Electronic Theses and Dissertations

As supercritical carbon dioxide (sCO2) power cycles have shown potential to be the next generation power cycle, an immense amount of research has gone into developing this system. One of the setbacks facing development and optimization of this cycle is the unknown in current design and analysis methods ability to accurately model turbomachinery working with sCO2. Due to the desired inlet conditions to the compressor close proximity to the critical point, accurate design and analysis of this power cycle component is one of the main concerns. The present study provides aerodynamic analysis of a centrifugal compressor impeller blade with sCO2 …

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Development Of Enzyme-Free Hydrogen Peroxide Biosensor Using Cerium Oxide And Mechanistic Study Using In-Situ Spectro-Electrochemistry, Shashank Saraf Jan 2016

Development Of Enzyme-Free Hydrogen Peroxide Biosensor Using Cerium Oxide And Mechanistic Study Using In-Situ Spectro-Electrochemistry, Shashank Saraf

Electronic Theses and Dissertations

During recent development, it has been demonstrated that cerium oxide nanoparticles (CNPs) have exhibited catalytic activity which mimics naturally existing enzymes such as superoxide dismutase (SOD) and catalase. The underlying mechanism is attributed to the modulation of oxygen vacancies on CNPs lattice by dynamic switching of the oxidation states between Ce3+ and Ce4+ due to the electron transfer resulting from the redox reaction between CNPs and reactive oxygen species such as hydrogen peroxide (H2O2). Thereby the redox potential of CNPs is dependent on the surface chemistry i.e. the surface concentration of Ce3+ and Ce4+ Currently, the ratio of Ce3+/ Ce4+ …

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Remote Sensing Of Coastal Wetlands: Long Term Vegetation Stress Assessment And Data Enhancement Technique, Subrina Tahsin Jan 2016

Remote Sensing Of Coastal Wetlands: Long Term Vegetation Stress Assessment And Data Enhancement Technique, Subrina Tahsin

Electronic Theses and Dissertations

Apalachicola Bay in the Florida panhandle is home to a rich variety of salt water and freshwater wetlands but unfortunately is also subject to a wide range of hydrologic extreme events. Extreme hydrologic events such as hurricanes and droughts continuously threaten the area. The impact of hurricane and drought on both fresh and salt water wetlands was investigated over the time period from 2000 to 2015 in Apalachicola Bay using spatio-temporal changes in the Landsat based NDVI. Results indicate that salt water wetlands were more resilient than fresh water wetlands. Results also suggest that in response to hurricanes, the coastal …

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Effects Of Climate Change And Anthropogenic Activities On The Everglades Landscape., Daljit Sandhu Jan 2016

Effects Of Climate Change And Anthropogenic Activities On The Everglades Landscape., Daljit Sandhu

Electronic Theses and Dissertations

The Everglades has been experiencing major changes, both climatic and anthropogenic, such that the landscape is experiencing additional stresses and forcings leading it away from its natural equilibrium. The land within and surrounding the Everglades has undergone severe modifications that may have detrimental effects on wildlife and natural features, such as rivers and landscape connectivity. Here in this study, the main focus is on understanding and quantifying hydrologic and geomorphic signatures of climatic and anthropogenic changes on the Everglades landscape. For this, in particular, available data on natural hydrological processes was used, such as rainfall, groundwater elevation, streamflow as well …

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Sinkhole Monitoring Using Groundwater Table Data, Ton Tu Jan 2016

Sinkhole Monitoring Using Groundwater Table Data, Ton Tu

Electronic Theses and Dissertations

Florida might be one of the most sinkhole-active areas on the earth. Due to its unpredictability and significance of occurrence, the development of sinkhole monitoring techniques is imperative to minimize sinkhole-induced hazards. Several methods have been used to evaluate sinkhole risks, including destructive methods, such as Standard Penetrating Tests (SPT) and Cone Penetrating Tests (CPT), geophysical method, and sensor-based groundwater monitoring method. However, few studies are available for comprehensive understanding of spatiotemporal sinkhole mechanism by combining different exploration methods under realistic experimental conditions. The objective of this study is to understand spatiotemporal sinkhole mechanism, using SPT, CPT, ground penetrating radar …

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Data-Driven Predictive Analytics For Distributed Smart Grid Control, Hamed Valizadehhaghi Jan 2016

Data-Driven Predictive Analytics For Distributed Smart Grid Control, Hamed Valizadehhaghi

Electronic Theses and Dissertations

The smart grid is expected to support an interconnected network of self-contained microgrids. Nonetheless, the distributed integration of renewable generation and demand response adds complexity to the control and optimization of smart grid. Forecasts are essential due to the existence of stochastic variations and uncertainty. Forecasting data are spatio-temporal which means that the data correspond to regular intervals, say every hour, and the analysis has to take account of spatial dependence among the distributed generators or locations. Hence, smart grid operations must take account of, and in fact benefit from the temporal dependence as well as the spatial dependence. This …

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Aeroelastic Investigation Of A Circumferentially Varying Tip Gap In An Axial Compressor Rotor, Ornan David Canon Jan 2016

Aeroelastic Investigation Of A Circumferentially Varying Tip Gap In An Axial Compressor Rotor, Ornan David Canon

Electronic Theses and Dissertations

The tip leakage flow in axial compressors is a significant factor in engine performance and a subject of investigation over the last several decades. Many studies have already shown that the vortices generated by this tip leakage can have a negative impact on the surrounding flow field and overall performance, and could potentially lead to excitations as well. This study examines the effect of these vortices on aeroelasticity. Specifically, it looks at the effect from a circumferentially varying tip gap, such as that produced by casing ovalization. For this project, the casing ovalization of an industrial gas turbine compressor was …

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Mechanistic Behavior Of Uhpc And Uhpc Composite Structural Components, Munaf Al-Ramahee Jan 2016

Mechanistic Behavior Of Uhpc And Uhpc Composite Structural Components, Munaf Al-Ramahee

Electronic Theses and Dissertations

The resistance of reinforced concrete is mobilized through the composite action of two materials with different mechanical behaviors and physical features. Enabling the composite action requires a transfer mechanism between the concrete and the reinforcement which is referred to as bond. The bond model can be defined as a traction-slip relation tangent to the interface. The bond strength between different types of concrete, internal reinforcement, and external reinforcement has been of interest to structural engineers for decades. Experimental tests have been carried out to validate the existing bond models and introduce new bond models for special cases of concrete or …

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Nanoengineered Energy Harvesting And Storage Devices, Chao Li Jan 2016

Nanoengineered Energy Harvesting And Storage Devices, Chao Li

Electronic Theses and Dissertations

Organic and perovskite solar cells have recently attracted significant attention due to its flexibility, ease of fabrication and excellent performance. In order to realize even better performance for organic and perovskite solar cells, rejuvenated effort towards developing nanostructured electrodes and high quality active layer is necessary. In this dissertation, several strategic directions of enhancing the performance of organic and perovskite solar cells are investigated. An introduction and background of organic and perovskite solar cells, which includes motivation, classification and working principles, nanostructured electrode materials and solvent effect on active materials, and devices fabrication, are presented. A facile method, called Spin-on …

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