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Full-Text Articles in Engineering

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 …


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 …


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 …


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 …


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 …


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 …


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 …


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. …


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 …


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, …


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 …


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 …


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 …


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 …


Green Technologies And Sensor Networks For Bmp Evaluation In Stormwater Retention Ponds And Wetlands., Anthony Crawford Jan 2014

Green Technologies And Sensor Networks For Bmp Evaluation In Stormwater Retention Ponds And Wetlands., Anthony Crawford

Electronic Theses and Dissertations

The aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of Environmental Protection (FDEP) has set forth reduction goals as established in Total Maximum Daily Load (TMDL) reports to reduce nutrient loading and restore, or maintain, Florida water …


Graphene Oxide Reinforcement In Plasma Sprayed Nickel-5%Aluminum Coatings, David Ward Jan 2014

Graphene Oxide Reinforcement In Plasma Sprayed Nickel-5%Aluminum Coatings, David Ward

Electronic Theses and Dissertations

Metallic plasma sprayed coatings are widely used in the aerospace industry for repair on worn engine components. However, the inherent defects in these coatings limit the variety of repairs and reduce the service life of the repaired parts. A potential solution to overcome this problem is to mix small amounts of inexpensive graphene oxide in the powder feedstock. The incredible strength to weight ratio of graphene oxide makes it a viable additive to improve mechanical properties of metallic plasma sprayed coatings. The powder system chosen for this research is Nickel-5Aluminum since it is a common coating for such repairs. The …


Instructional Strategies For Scenario-Based Training Of Human Behavior Cue Analysis With Robot-Aided Intelligence, Surveillance, Reconnaissance, Julie Salcedo Jan 2014

Instructional Strategies For Scenario-Based Training Of Human Behavior Cue Analysis With Robot-Aided Intelligence, Surveillance, Reconnaissance, Julie Salcedo

Electronic Theses and Dissertations

The U.S. Army desires to improve safety during Intelligence, Surveillance, Reconnaissance (ISR) operations by removing Warfighters from direct line-of-fire by enhancing ISR operational capabilities with unmanned systems, also known as Robot-Aided ISR (RAISR) (DOD, 2013). Additionally, RAISR presents an opportunity to fulfill ISR capability requirements of modern combat environments including: detection of High-Value Individuals (HVI) from safer distances, identification of baseline behavior, and interpretation of adversarial intent (U.S. Army, 2008). Along with the demand and projected acquisition of RAISR technology, there is the added need to design training requirements for system operation and task execution instruction. While documentation identifying specific …


Combustion Instability Mechanism Of A Reacting Jet In Cross Flow At Gas Turbine Operating Conditions, Jared Pent Jan 2014

Combustion Instability Mechanism Of A Reacting Jet In Cross Flow At Gas Turbine Operating Conditions, Jared Pent

Electronic Theses and Dissertations

Modern gas turbine designs often include lean premixed combustion for its emissions benefits; however, this type of combustion process is susceptible to self-excited combustion instabilities that can lead to damaging heat loads and system vibrations. This study focuses on identifying a mechanism of combustion instability of a reacting jet in cross flow, a flow feature that is widely used in the design of gas turbine combustion systems. Experimental results from a related study are used to validate and complement three numerical tools that are applied in this study – self-excited Large Eddy Simulations, 3D thermoacoustic modeling, and 1D instability modeling. …


In-Situ Synchrotron Studies Of Turbine Blade Thermal Barrier Coatings Under Extreme Environments, Kevin Knipe Jan 2014

In-Situ Synchrotron Studies Of Turbine Blade Thermal Barrier Coatings Under Extreme Environments, Kevin Knipe

Electronic Theses and Dissertations

Thermal Barrier Coatings have been used for decades to impose a thermal gradient between the hot combustion gases and the underlying superalloy substrate in engine turbine blades. Yttria Stabilized Zirconia (YSZ) is an industry standard high temperature ceramic for turbine applications. The protective coating is adhered to the substrate using a nickel based alloy bond coat. Through exposure to high temperature, a Thermally Grown Oxide (TGO) layer develops at the bond coat-YSZ interface. Large residual stresses develop in these layers due to thermal expansion mismatch that occurs during cool down from high temperature spraying and cyclic operating conditions. Despite their …


Synchrotron X-Ray Diffraction And Piezospectroscopy Used For The Investigation Of Individual Mechanical Effects From Environmental Contaminants And Oxide Layer Undulations In Thermal Barrier Coatings, Sanna Siddiqui Jan 2014

Synchrotron X-Ray Diffraction And Piezospectroscopy Used For The Investigation Of Individual Mechanical Effects From Environmental Contaminants And Oxide Layer Undulations In Thermal Barrier Coatings, Sanna Siddiqui

Electronic Theses and Dissertations

The durability of Thermal Barrier Coatings (TBCs) used on the turbine blades of aircraft and power generation engines has been known to be affected by sand particle ingression comprised of Calcium-Magnesium-Alumina-Silicate (CMAS). Previous studies have shown that these effects present themselves through variations in the thermomechanical and thermochemical properties of the coating. This study investigated the impact of CMAS ingression on the Yttria Stabilized Zirconia Topcoat (YSZ) and Thermally Grown Oxide (TGO) strain in sprayed Thermal Barrier Coating (TBC) samples of varying porosity with and without CMAS ingression. In-Situ Synchrotron X-ray Diffraction measurements were taken on the sample under thermal …


Nanocomposite Coating Mechanics Via Piezospectroscopy, Gregory Freihofer Jan 2014

Nanocomposite Coating Mechanics Via Piezospectroscopy, Gregory Freihofer

Electronic Theses and Dissertations

Coatings utilizing the piezospectroscopic (PS) effect of alpha alumina could enable on the fly stress sensing for structural health monitoring applications. While the PS effect has been historically utilized in several applications, here by distributing the photo-luminescent material in nanoparticle form within a matrix, a stress sensing coating is created. Parallel to developing PS coatings for stress sensing, the multi-scale mechanics associated with the observed PS response of nanocomposites and their coatings has been applied to give material property measurements, providing an understanding of particle reinforced composite behavior. Understanding the nanoparticle-coating-substrate mechanics is essential to interpreting the spectral shifts for …


Processing And Characterization Of Multifunctional Thermoplastic Nanocomposite Films, Xin Wang Jan 2014

Processing And Characterization Of Multifunctional Thermoplastic Nanocomposite Films, Xin Wang

Electronic Theses and Dissertations

Nanoparticles reinforced polymer composite films have been widely studied for their enhanced mechanical, electrical and thermal properties compared with host polymer matrix. However, most research was conducted on incorporation of nanoparticles in polymer films to improve single property and there is a lack of research on the multifunctional polymer nanocomposite films. In this work, a scalable and continuous spray deposition process was developed for the production of nanoparticles reinforced multifunctional thermoplastic nanocomposite films. This process is capable of making a thin sheet of thermoplastic nanocomposites with high nanoparticle loadings. The smallest thickness can be 40um. The objective of this study …


Investigation Of Different Dielectric Materials As Gate Insulator For Mosfets, Ritika Oswal Jan 2014

Investigation Of Different Dielectric Materials As Gate Insulator For Mosfets, Ritika Oswal

Electronic Theses and Dissertations

The scaling of semiconductor transistors has led to a decrease in thickness of the silicon dioxide layer used as gate dielectric. The thickness of the silicon dioxide layer is reduced to increase the gate capacitance, thus increasing the drain current. If the thickness of the gate dielectric decreases below 2nm, the leakage current due to the tunneling increases drastically. Hence it is necessary to replace the gate dielectric, silicon dioxide, with a physically thicker oxide layer of high-k materials like Hafnium oxide and Titanium oxide. High-k dielectric materials allow the capacitance to increase without a huge leakage current. Hafnium oxide …


Automatic 3d Human Modeling: An Initial Stage Towards 2-Way Inside Interaction In Mixed Reality, Yiyan Xiong Jan 2014

Automatic 3d Human Modeling: An Initial Stage Towards 2-Way Inside Interaction In Mixed Reality, Yiyan Xiong

Electronic Theses and Dissertations

3D human models play an important role in computer graphics applications from a wide range of domains, including education, entertainment, medical care simulation and military training. In many situations, we want the 3D model to have a visual appearance that matches that of a specific living person and to be able to be controlled by that person in a natural manner. Among other uses, this approach supports the notion of human surrogacy, where the virtual counterpart provides a remote presence for the human who controls the virtual character's behavior. In this dissertation, a human modeling pipeline is proposed for the …


An Introductory Study Of The Dynamics Of Autorotation For Wind Energy Harvesting, Bilal Salih Jan 2014

An Introductory Study Of The Dynamics Of Autorotation For Wind Energy Harvesting, Bilal Salih

Electronic Theses and Dissertations

Wind turbines have been used for decades to harvest wind energy. They are suitable only to work on close to ground, and have several drawbacks that are related to the availability of the wind and the amount of extracted power compared with the cost of construction. On the other hand, there is an abundant wind power that is available at high altitudes. The wind jet streams at high elevations 8 - 12 kms are pervasive and persistent, and can potentially produce immense wind energy. Even at moderate elevations of 4 - 5 kms, wind power densities are much higher than …


A Continuous Hydrologic Model Structure For Applications At Multiple Time Scales, Jonathan Griffen Jan 2014

A Continuous Hydrologic Model Structure For Applications At Multiple Time Scales, Jonathan Griffen

Electronic Theses and Dissertations

There are many different controlling factors on the partitioning of rainfall into runoff. However, the influence of each of these controls varies across different temporal scales. Consequently, numerous water balance models have been developed in the literature for application across various time scales. These models are usually developed for a particular time scale so that the controls with the greatest influence on rainfall partitioning are captured. For example, the SCS curve number method was developed to simulate direct runoff at the event scale; the "abcd" model was developed as a monthly water balance model; and the Budyko model was developed …


Evaluating The Effectiveness Of Conversion Of Traditional Five Section Head Signal To Flashing Yellow Arrow (Fya) Signal, Meshal Almoshaogeh Jan 2014

Evaluating The Effectiveness Of Conversion Of Traditional Five Section Head Signal To Flashing Yellow Arrow (Fya) Signal, Meshal Almoshaogeh

Electronic Theses and Dissertations

In the United States, there are two schemes of operating traffic signal controls for permitted protected left turns (PPLT) namely the traditional five-section head system (known as Dog-House) and the flashing yellow arrow system (FYA). Past studies have agreed that these controls lead to decrease the average delay per left turn vehicle, decrease the protected green time, increase the left turn capacity, and enhance the intersection overall operation. The flashing yellow arrow (FYA) has been approved by the Federal Highway Administration as the national standard for the PPLT operations at signalized intersections. So, the Florida Department of Transportation also approved …


Exploring Sparsity, Self-Similarity, And Low Rank Approximation In Action Recognition, Motion Retrieval, And Action Spotting, Chuan Sun Jan 2014

Exploring Sparsity, Self-Similarity, And Low Rank Approximation In Action Recognition, Motion Retrieval, And Action Spotting, Chuan Sun

Electronic Theses and Dissertations

This thesis consists of 4 major parts. In the first part (Chapters 1-2), we introduce the overview, motivation, and contribution of our works, and extensively survey the current literature for 6 related topics. In the second part (Chapters 3-7), we explore the concept of "Self-Similarity" in two challenging scenarios, namely, the Action Recognition and the Motion Retrieval. We build three-dimensional volume representations for both scenarios, and devise effective techniques that can produce compact representations encoding the internal dynamics of data. In the third part (Chapter 8), we explore the challenging action spotting problem, and propose a feature-independent unsupervised framework that …


Placement Of Mode And Wavelength Converters For Throughput Enhancement In Optical Networks, Ruaa Abdulrahman Jan 2014

Placement Of Mode And Wavelength Converters For Throughput Enhancement In Optical Networks, Ruaa Abdulrahman

Electronic Theses and Dissertations

The success of recent experiments to transport data using combined wavelength division multiplexed (WDM) and mode-division multiplexed (MDM) transmission has generated optimism for the attainment of optical networks with unprecedented bandwidth capacity, exceeding the fundamental Shannon capacity limit attained by WDM alone. Optical mode converters and wavelength converters are devices that can be placed in future optical nodes (routers) to prevent or reduce the connection blocking rate and consequently increase network throughput. In this thesis, the specific problem of the placement of mode converters (MC) and mode-wavelength converters (MWC) in combined mode and wavelength division multiplexing (MWDM) networks is investigated. …


Treatment-Specific Approaches For Analysis And Control Of Left Ventricular Assist Devices, George Faragallah Jan 2014

Treatment-Specific Approaches For Analysis And Control Of Left Ventricular Assist Devices, George Faragallah

Electronic Theses and Dissertations

A Left Ventricular Assist Device (LVAD) is a mechanical pump that helps patients with heart failure conditions. This rotary pump works in parallel to the ailing heart and provides an alternative path for blood flow from the weak left ventricle to the aorta. The LVAD is controlled by the power supplied to the pump motor. An increase in the pump motor power increases the pump speed and the pump flow. The LVAD is typically controlled at a fixed setting of pump power. This basically means that the controller does not react to any change in the activity level of the …