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2014

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Articles 5851 - 5880 of 7238

Full-Text Articles in Engineering

Perovskite Catalysts Enhanced Combustion On Porous Media And Thermoelectric Power Conversion, Manuel Robayo Jan 2014

Perovskite Catalysts Enhanced Combustion On Porous Media And Thermoelectric Power Conversion, Manuel Robayo

Electronic Theses and Dissertations

A combustion chamber incorporating a high temperature porous matrix was design and tested. The effects and merits of combining combustion on porous media and catalytic enhancement were explored, in addition to the proof of concept of integrating these technologies with simple heat engines, such as thermoelectric generators, to generate efficient and reliable power. The direct observation of the flame during the combustion becomes possible due to a specially designed stainless steel chamber incorporating a quartz window where the initiation and propagation of the combustion reaction/flame was directly visible. The simple design of the combustion chamber allowed for a series of …

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Stochastic Optimization For Integrated Energy System With Reliability Improvement Using Decomposition Algorithm, Yuping Huang Jan 2014

Stochastic Optimization For Integrated Energy System With Reliability Improvement Using Decomposition Algorithm, Yuping Huang

Electronic Theses and Dissertations

As energy demands increase and energy resources change, the traditional energy system has been upgraded and reconstructed for human society development and sustainability. Considerable studies have been conducted in energy expansion planning and electricity generation operations by mainly considering the integration of traditional fossil fuel generation with renewable generation. Because the energy market is full of uncertainty, we realize that these uncertainties have continuously challenged market design and operations, even a national energy policy. In fact, only a few considerations were given to the optimization of energy expansion and generation taking into account the variability and uncertainty of energy supply …

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Remote Sensing With Computational Intelligence Modelling For Monitoring The Ecosystem State And Hydraulic Pattern In A Constructed Wetland, Golam Mohiuddin Jan 2014

Remote Sensing With Computational Intelligence Modelling For Monitoring The Ecosystem State And Hydraulic Pattern In A Constructed Wetland, Golam Mohiuddin

Electronic Theses and Dissertations

Monitoring the heterogeneous aquatic environment such as the Stormwater Treatment Areas (STAs) located at the northeast of the Everglades is extremely important in understanding the land processes of the constructed wetland in its capacity to remove nutrient. Direct monitoring and measurements of ecosystem evolution and changing velocities at every single part of the STA are not always feasible. Integrated remote sensing, monitoring, and modeling technique can be a state-of-the-art tool to estimate the spatial and temporal distributions of flow velocity regimes and ecological functioning in such dynamic aquatic environments. In this presentation, comparison between four computational intelligence models including Extreme …

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Safety Effectiveness Of Conversion Of Two-Way-Left-Turn Lanes Into Raised Medians, Saif Alarifi Jan 2014

Safety Effectiveness Of Conversion Of Two-Way-Left-Turn Lanes Into Raised Medians, Saif Alarifi

Electronic Theses and Dissertations

Two way left turn lanes (TWLTL) and raised medians are common median treatments on roadways. This research focused on evaluating the safety effectiveness of conversion of TWLTLs into raised medians using Before-After and Cross Sectional Studies. In the Before-After Studies, we evaluated the effect of this treatment using the Naive, Before-After with Comparison Group (CG), and Before-After with Empirical Bayes (EB) Methods. In order to apply these methods, a total of 33 segments of a treated group and 109 segments of a comparison group have been collected. Also, safety performance functions (SPFs) have been developed using the negative binomial model …

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Modeling And Contour Control Of Multi-Axis Linear Driven Machine Tools, Ran Zhao Jan 2014

Modeling And Contour Control Of Multi-Axis Linear Driven Machine Tools, Ran Zhao

Electronic Theses and Dissertations

In modern manufacturing industries, many applications require precision motion control of multi-agent systems, like multi-joint robot arms and multi-axis machine tools. Cutter (end effector) should stay as close as possible to the reference trajectory to ensure the quality of the final products. In conventional computer numerical control (CNC), the control unit of each axis is independently designed to achieve the best individual tracking performance. However, this becomes less effective when dealing with multi-axis contour following tasks because of the lack of coordination among axes. This dissertation studies the control of multi-axis machine tools with focus on reducing the contour error. …

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Uncertainty Treatment In Performance Based Seismic Assessment Of Typical Bridge Classes In United States, Mohammad Mehdizadeh Jan 2014

Uncertainty Treatment In Performance Based Seismic Assessment Of Typical Bridge Classes In United States, Mohammad Mehdizadeh

Electronic Theses and Dissertations

Bridge networks are expensive and complex infrastructures and are essential components of today's transportation systems. Despite the advancement in computer aided modeling and increasing the computational power which is increasing the accessibility for developing the fragility curves of bridges, the complexity of the problem and uncertainties involved in fragility analysis of the bridge structures in addition to difficulties in validating the results obtained from the analysis requires precaution in utilization of the results as a decision making tool. The main focus of this research is to address, study and treatment of uncertainties incorporated in various steps of performance based assessments …

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Transferability And Calibration Of The Highway Safety Manual Performance Functions And Development Of New Models For Urban Four-Lane Divided Roads, Kaaf, Khalid Al Jan 2014

Transferability And Calibration Of The Highway Safety Manual Performance Functions And Development Of New Models For Urban Four-Lane Divided Roads, Kaaf, Khalid Al

Electronic Theses and Dissertations

Many developing countries have witnessed fast and rapid growth in the last two decades due to the high development rate of economic activity in these countries. Many transportation projects have been constructed. In the same time both population growth and vehicle ownership rate increased; resulting in increasing levels of road crashes. Road traffic crashes in Gulf Cooperation Council (GCC) is considered a serious problem that has deep effects on GCC's population as well as on the national productivity through the loss of lives, injuries, property damage and the loss of valuable resources. From a recent statistical study of traffic crashes …

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Performance Evaluation Of Two Silt Fence Geosynthetic Fabrics During And After Rainfall Event, Gregg Dubinsky Jan 2014

Performance Evaluation Of Two Silt Fence Geosynthetic Fabrics During And After Rainfall Event, Gregg Dubinsky

Electronic Theses and Dissertations

Silt fence is one of the most widely used perimeter control devices and is considered an industry standard for use in the control of sediment transport from construction sites. Numerous research studies have been conducted on the use of silt fence as a perimeter control, including a number of studies involving controlled laboratory flume tests and outdoor tests performed in the field on construction sites with actual monitored storm events. In field tests, due to the random and uncontrollable nature of real storm events and field conditions, studies have shown difficulty in evaluating silt fence performance. These field studies have …

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Sketchart: A Pen-Based Tool For Chart Generation And Interaction., Andres Vargas Gonzalez Jan 2014

Sketchart: A Pen-Based Tool For Chart Generation And Interaction., Andres Vargas Gonzalez

Electronic Theses and Dissertations

It has been shown that representing data with the right visualization increases the understanding of qualitative and quantitative information encoded in documents. However, current tools for generating such visualizations involve the use of traditional WIMP techniques, which perhaps makes free interaction and direct manipulation of the content harder. In this thesis, we present a pen-based prototype for data visualization using 10 different types of bar based charts. The prototype lets users sketch a chart and interact with the information once the drawing is identified. The prototype's user interface consists of an area to sketch and touch based elements that will …

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Applications Of Transit Signal Priority Technology For Transit Service, Frank Anthony Consoli Jan 2014

Applications Of Transit Signal Priority Technology For Transit Service, Frank Anthony Consoli

Electronic Theses and Dissertations

This research demonstrated the effectiveness of Transit Signal Priority (TSP) in improving bus corridor travel time in a simulated environment using real world data. TSP is a technology that provides preferential treatment to buses at signalized intersections. By considering different scenarios of activating bus signal priority when a bus is 3 or 5 minutes behind schedule, it was demonstrated that bus travel times improved significantly while there is little effect on delays for crossing street traffic. The case of providing signal priority for buses unconditionally resulted in significant crossing street delays for some signalized intersections with only minor improvement to …

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A Curricula Assessment And Improvement Quantitative Model For Higher Education: A Design For Six Sigma Methodology, Abdullah Halawany Jan 2014

A Curricula Assessment And Improvement Quantitative Model For Higher Education: A Design For Six Sigma Methodology, Abdullah Halawany

Electronic Theses and Dissertations

Curricula assessment is an integrated process to assist higher education institutions in addressing the challenges in a designated field of study and in exploring the opportunities to better educate and prepare their students for an increasingly complex world. Although assessment as a topic has been researched extensively, there has been a lack of quantitative tools that address the requirements of many of the stakeholders that may be critical to the curriculum design and assessment processes. This research proposes the utilization of Design for Six Sigma (DFSS) to develop a quantitative model for curriculum assessment and improvement for higher education institutions. …

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Cost-Sensitive Learning-Based Methods For Imbalanced Classification Problems With Applications, Talayeh Razzaghi Jan 2014

Cost-Sensitive Learning-Based Methods For Imbalanced Classification Problems With Applications, Talayeh Razzaghi

Electronic Theses and Dissertations

Analysis and predictive modeling of massive datasets is an extremely significant problem that arises in many practical applications. The task of predictive modeling becomes even more challenging when data are imperfect or uncertain. The real data are frequently affected by outliers, uncertain labels, and uneven distribution of classes (imbalanced data). Such uncertainties create bias and make predictive modeling an even more difficult task. In the present work, we introduce a cost-sensitive learning method (CSL) to deal with the classification of imperfect data. Typically, most traditional approaches for classification demonstrate poor performance in an environment with imperfect data. We propose the …

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A Holistic Framework For Transitional Management, Ahmed Elattar Jan 2014

A Holistic Framework For Transitional Management, Ahmed Elattar

Electronic Theses and Dissertations

For all business organizations, there comes a time when a change must take place within their eco-system. It consumes a great deal of thought and planning to ensure that the right decision is made as it could alter the entire course of their business for a number of years to come. This change may appear in the form of a brilliant CEO reaching the age of retirement, or an unsuccessful Managing Director being asked to leave before fulfilling the term of her contract. Regardless of the cause, a transition must occur in which a suitable successor is chosen and put …

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Analysis Of Taxi Drivers' Driving Behavior Based On A Driving Simulator Experiment, Jiawei Wu Jan 2014

Analysis Of Taxi Drivers' Driving Behavior Based On A Driving Simulator Experiment, Jiawei Wu

Electronic Theses and Dissertations

Due to comfort, convenience, and flexibility, taxis become more and more prevalent in China, especially in large cities. According to a survey reported by Beijing Traffic Development Research Center, there were 696 million taxi person-rides in Beijing in 2011. However, many violations and road crashes that were related to taxi drivers occurred more frequently. The survey showed that there were a total of 17,242 taxi violations happened in Beijing in only one month in 2003, which accounted for 56% of all drivers' violations. Besides, taxi drivers also had a larger accident rate than other drivers, which showed that nearly 20% …

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Energy Efficient Routing Towards A Mobile Sink Using Virtual Coordinates In A Wireless Sensor Network, Rouhollah Rahmatizadeh Jan 2014

Energy Efficient Routing Towards A Mobile Sink Using Virtual Coordinates In A Wireless Sensor Network, Rouhollah Rahmatizadeh

Electronic Theses and Dissertations

The existence of a coordinate system can often improve the routing in a wireless sensor network. While most coordinate systems correspond to the geometrical or geographical coordinates, in recent years researchers had proposed the use of virtual coordinates. Virtual coordinates depend only on the topology of the network as defined by the connectivity of the nodes, without requiring geographical information. The work in this thesis extends the use of virtual coordinates to scenarios where the wireless sensor network has a mobile sink. One reason to use a mobile sink is to distribute the energy consumption more evenly among the sensor …

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Beneficial Utilization Of Municipal Solid Waste Incineration Ashes As Sustainable Road Construction Materials, Kazi Tasneem Jan 2014

Beneficial Utilization Of Municipal Solid Waste Incineration Ashes As Sustainable Road Construction Materials, Kazi Tasneem

Electronic Theses and Dissertations

Incineration of municipal solid waste (MSW) is common for energy recovery, and management of municipal solid waste incineration (MSWI) ashes has received a growing attention around the world. In the U.S., generation of MSW has increased up to 65% since 1980, to the current level of 251 million tons per year with 53.8% landfilled, 34.5% recycled and composted, and 11.7% incinerated with energy recovery. In the process of incineration, MSWI ash is being produced as byproducts; about 80 to 90% of the MSWI ash is bottom ash (BA) and 10 to 20% is fly ash (FA) by weight. The current …

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A New Multidimensional Psycho-Physical Framework For Modeling Car-Following In A Freeway Work Zone, Taylor Lochrane Jan 2014

A New Multidimensional Psycho-Physical Framework For Modeling Car-Following In A Freeway Work Zone, Taylor Lochrane

Electronic Theses and Dissertations

As the United States continues to build and repair the ageing highway infrastructure, the bearing of freeway work zones will continue to impact the capacity. To predict the capacity of a freeway work zone, there are several tools available for engineers to evaluate these work zones but only microsimulation has the ability to simulate the driver behavior. One of the limitations of current car-following models is that they only account for one overall behavioral condition. This dissertation hypothesizes that drivers change their driving behavior as they drive through a freeway work zone compared to normal freeway conditions which has the …

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Decentralized Power Management And Transient Control In Hybrid Fuel Cell Ultra-Capacitor System, Seyed Omid Madani Jan 2014

Decentralized Power Management And Transient Control In Hybrid Fuel Cell Ultra-Capacitor System, Seyed Omid Madani

Electronic Theses and Dissertations

Solid Oxide Fuel Cells (SOFCs) are considered suitable for alternative energy solutions due to advantages such as high efficiency, fuel flexibility, tolerance to impurities, and potential for combined cycle operations. One of the main operating constraints of SOFCs is fuel starvation, which can occur under fluctuating power demands. It leads to voltage loss and detrimental effects on cell integrity and longevity. In addition, reformer based SOFCs require sufficient steam for fuel reforming to avoid carbon deposition and catalyst degradation. Steam to carbon ratio (STCR) is an index indicating availability of the steam in the reformer. This work takes a holistic …

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Assessing Safety Culture Among Pilots In Saudi Airlines: A Quantitative Study Approach, Mohammad Alsowayigh Jan 2014

Assessing Safety Culture Among Pilots In Saudi Airlines: A Quantitative Study Approach, Mohammad Alsowayigh

Electronic Theses and Dissertations

In high- risk industries, such as aviation, safety is a key for organization survivor. Most accidents involve human losses and bring substantial cost to organizations. Accidents can devastate the reputation and profitability of any organization. In aviation, more than 80% of aircraft accidents are related to human errors. Safety culture has substantial impact on the success of any organization. Employees' performance and behaviors are influenced by their perception of safety culture within their organization. In the aviation industry, pilots are considered the last resort to prevent accidents or mishaps in the air or ground. The focus on pilots' perception of …

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A Framework For Measuring And Analyzing Customer Satisfaction At Computer Service Company Using Lean Six Sigma, Mohammed Abboodi Jan 2014

A Framework For Measuring And Analyzing Customer Satisfaction At Computer Service Company Using Lean Six Sigma, Mohammed Abboodi

Electronic Theses and Dissertations

The computer service industry has been expanding dramatically due to the increase in the number of computing machineries in the last two decades. The entrance of large size companies in the market and the release of online tools that have the ability for diagnosing and troubleshooting hardware and software issues have boosted the competition. In the meantime, many of the small and medium size companies find themselves unable to keep their customers satisfied since their competitors provide high quality service with lower cost. The lack of a good measurement system to assess and analyze the satisfaction level with the provided …

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A Comparative Analysis Of Different Dilemma Zone Countermeasures At Signalized Intersections Based On Cellular Automaton Model, Yina Wu Jan 2014

A Comparative Analysis Of Different Dilemma Zone Countermeasures At Signalized Intersections Based On Cellular Automaton Model, Yina Wu

Electronic Theses and Dissertations

In the United States, intersections are among the most frequent locations for crashes. One of the major problems at signalized intersection is the dilemma zone, which is caused by false driver behavior during the yellow interval. This research evaluated driver behavior during the yellow interval at signalized intersections and compared different dilemma zone countermeasures. The study was conducted through four stages. First, the driver behavior during the yellow interval were collected and analyzed. Eight variables, which are related to risky situations, are considered. The impact factors of drivers' stop/go decisions and the presence of the red-light running (RLR) violations were …

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Development Of Treatment Train Techniques For The Evaluation Of Low Impact Development In Urban Regions, Mike Hardin Jan 2014

Development Of Treatment Train Techniques For The Evaluation Of Low Impact Development In Urban Regions, Mike Hardin

Electronic Theses and Dissertations

Stormwater runoff from urban areas is a major source of pollution to surface water bodies. The discharge of nutrients such as nitrogen and phosphorus is particularly damaging as it results in harmful algal blooms which can limit the beneficial use of a water body. Stormwater best management practices (BMPs) have been developed over the years to help address this issue. While BMPs have been investigated for years, their use has been somewhat limited due to the fact that much of the data collected is for specific applications, in specific regions, and it is unknown how these systems will perform in …

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Evaluation Of Iron And Manganese Control For A Volcanic Surface Water Supply Treated With Conventional Coagulation, Sedimentation And Filtration Processes, Christine Hall Jan 2014

Evaluation Of Iron And Manganese Control For A Volcanic Surface Water Supply Treated With Conventional Coagulation, Sedimentation And Filtration Processes, Christine Hall

Electronic Theses and Dissertations

A research project assessing the effectiveness of potassium permanganate (KMnO4) for the treatment of iron (Fe) and manganese (Mn) has been conducted by the University of Central Florida (UCF) on behalf of the United States Navy with regards to the water supply on the island of Guam, located in the Marianas Islands. The study consisted of three basic investigative components: one that examined the use of potassium permanganate for iron and manganese control for Fena Lake, a second that examined the existing unit operations that comprised the Navy's water treatment plant (NWTP), and a third that examined iron and manganese …

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Dishwashing Water Recycling System And Related Water Quality Standards For Military Use, Jared Church Jan 2014

Dishwashing Water Recycling System And Related Water Quality Standards For Military Use, Jared Church

Electronic Theses and Dissertations

As the demand for reliable and safe water supplies increases, both water quality and available quantity are being challenged by population growth and climate change. Greywater reuse is becoming a common practice worldwide; however, in remote locations of limited water supply, such as those encountered in military installations, it is desirable to expand its classification to include dishwashing water to maximize the conservation of fresh water. Given that no standards for dishwashing greywater reuse by the military are currently available, the current study determined a specific set of water quality standards for dishwater recycling systems for U.S military field operations. …

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Modeling And Spray Pyrolysis Processing Of Mixed Metal Oxide Nano-Composite Gas Sensor Films, Seyed Mohammad Navid Khatami Jan 2014

Modeling And Spray Pyrolysis Processing Of Mixed Metal Oxide Nano-Composite Gas Sensor Films, Seyed Mohammad Navid Khatami

Electronic Theses and Dissertations

The role of sensor technology is obvious in improvement and optimization of many industrial processes. The sensor films, which are considered the core of chemical sensors, have the capability to detect the presence and concentration of a specific chemical substance. Such sensor films achieve selectivity by detecting the interaction of the specific chemical substance with the sensor material through selective binding, adsorption and permeation of analyte. This research focuses on development and verification of a comprehensive mathematical model of mixed metal oxide thin film growth using spray pyrolysis technique (SPT). An experimental setup is used to synthesize mixed metal oxide …

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Traffic Safety Assessment Of Different Toll Collection Systems On Expressways Using Multiple Analytical Techniques, Muamer Abuzwidah Jan 2014

Traffic Safety Assessment Of Different Toll Collection Systems On Expressways Using Multiple Analytical Techniques, Muamer Abuzwidah

Electronic Theses and Dissertations

Traffic safety has been considered one of the most important issues in the transportation field. Crashes have caused extensive human and economic losses. With the objective of reducing crash occurrence and alleviating crash injury severity, major efforts have been dedicated to reveal the hazardous factors that affect crash occurrence. With these consistent efforts, both fatalities and fatality rates from road traffic crashes in many countries have been steadily declining over the last ten years. Nevertheless, according to the World Health Organization, the world still lost 1.24 million lives from road traffic crashes in the year of 2013. And without action, …

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Urban Expressway Safety And Efficiency Evaluation And Improvement Using Big Data, Qi Shi Jan 2014

Urban Expressway Safety And Efficiency Evaluation And Improvement Using Big Data, Qi Shi

Electronic Theses and Dissertations

In an age of data explosion, almost every aspect of social activities is impacted by the abundance of information. The information, characterized by alarming volume, velocity and variety, is often referred to as "Big Data". As one fundamental elements of human life, transportation also confronts the promises and challenges brought about by the Big Data era. Big Data in the transportation arena, enabled by the rapid popularization of Intelligent Transportation Systems (ITS) in the past few decades, are often collected continuously from different sources over vast geographical scale. Huge in size and rich in information, the seemingly disorganized data could …

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Rhenium, Osmium And Iridium Diborides By Mechanochemistry: Synthesis, Structure, Thermal Stability And Mechanical Properties, Zhilin Xie Jan 2014

Rhenium, Osmium And Iridium Diborides By Mechanochemistry: Synthesis, Structure, Thermal Stability And Mechanical Properties, Zhilin Xie

Electronic Theses and Dissertations

Borides are implemented in a range of industrial applications due to their unique mechanical, electrical, thermal and catalytic properties. In particular, transition metal diborides are of special interest. In the recent years, borides of rhenium (Re), osmium (Os) and iridium (Ir) have been studied as for their ultra-hardness and superior stiffness. In this dissertation, a mechanochemical method is introduced to produce rhenium diboride (ReB2) powder, a novel hexagonal osmium diboride (h-OsB2), and iridium boride powders. Densification by Spark Plasma Sintering (SPS), thermal stability and mechanical properties of h-OsB2 were also studied. ReB2 was recently reported to exhibit high hardness and …

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Ignition Studies Of Diisopropyl Ketone, A Second-Generation Biofuel, Owen Pryor Jan 2014

Ignition Studies Of Diisopropyl Ketone, A Second-Generation Biofuel, Owen Pryor

HIM 1990-2015

This thesis focuses on ignition of diisopropyl ketone (DIPK), a new biofuel candidate that is produced by endophytic conversion. The ignition delay times behind reflected shockwaves were modeled in a high-pressure shock tube. The ignition delay times were compared to other biofuels and gasoline surrogates. Parametric studies of the ignition delay experiments were performed between 1-10 atm and 900 -1200K. An OH optical sensor was developed in conjunction for the ignition delay experiments. The OH optical sensor uses a microwave discharge lamp to generate light at 308 nm that will then be shined through the combustion reaction. Using Beer-Lambert law …

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Nondestructive Analysis Of Advanced Aerospace Materials Via Spectroscopy And Synchrotron Radiation, Albert Manero Jan 2014

Nondestructive Analysis Of Advanced Aerospace Materials Via Spectroscopy And Synchrotron Radiation, Albert Manero

Electronic Theses and Dissertations

Advanced aerospace materials require extensive testing and characterization to anticipate and ensure their integrity under hostile environments. Characterization methods utilizing synchrotron X-Ray diffraction and spectroscopy can decrease the time required to determine an emerging material's readiness for application through intrinsic information on the material response and failure mechanisms. In this study, thermal barrier coating samples applicable to turbine blades of jet engines were studied using Raman and Photoluminescence spectroscopy as well as Synchrotron X-ray diffraction while Kevlar based fiber composites applicable to ballistic resistant armor were studied using Raman spectroscopy to investigate the mechanical state and corresponding damage and failure …

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