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2011

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Articles 1231 - 1260 of 5801

Full-Text Articles in Engineering

Construction Training For The Current And Next Generation Of Technicians, Paul M. Goodrum, Dong Zhai Aug 2011

Construction Training For The Current And Next Generation Of Technicians, Paul M. Goodrum, Dong Zhai

Kentucky Transportation Center Research Report

Technicians are a vital component to the success of any roadway projects. Unfortunately, the Kentucky Transportation Cabinet (KYTC) is experiencing significant shortages of technicians among all aspects of construction and maintenance. Training and developing the adequate numbers of qualified technicians is a substantial endeavor that requires a comprehensive examination of the adequacy of current training program versus the anticipated skill needs of technicians on future projects. Two questionnaires were developed to identify this gap. One is to investigate the skills and trainings that the Cabinet’s technicians possesses and received, and the second is to investigate the skills and/or knowledge which …


Experimental Coating On Interstate 264 In Jefferson County, Bobby W. Meade, Sudhir Palle, Theodore Hopwood Ii Aug 2011

Experimental Coating On Interstate 264 In Jefferson County, Bobby W. Meade, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

A waterborne acrylic coating was applied over a washed and tool cleaned zinc/vinyl system as a maintenance overcoat. The coating has several positive characteristics in that it is “user friendly”, substrate tolerant, develops good adhesion quickly, and is environmentally friendly. There were some issues concerning quality of work in surface preparation and application and in the fact that on two locations bubbles developed in the newly applied coating. The cause of the bubbling has not been determined.


Kinetic Analysis Of The Thermal Degradation Of Printed Wiring Boards, Alex Luyima, Lifeng Zhang, Lucas Nana Wiredu Damoah Aug 2011

Kinetic Analysis Of The Thermal Degradation Of Printed Wiring Boards, Alex Luyima, Lifeng Zhang, Lucas Nana Wiredu Damoah

Materials Science and Engineering Faculty Research & Creative Works

The non-isothermal pyrolysis of printed wiring boards (PWBs) was investigated by simultaneous thermogravimetric and differential thermal analysis (TG-DTA) in the temperature range of 300-1200 K. Pyrolysis experiments were carried out on PWBs samples at three different heating rates of 10, 20, and 30°C/min. in this study, the kinetic parameters of PWBs pyrolysis have been estimated using model free and model fitted methods. © 2011 TMS.


Mixture Fraction Imaging Based On Photodissociation Spectroscopy And Two Photon Laser Induced Fluorescence, Yan Zhao Aug 2011

Mixture Fraction Imaging Based On Photodissociation Spectroscopy And Two Photon Laser Induced Fluorescence, Yan Zhao

All Dissertations

The study of turbulent combustion calls for new diagnostics that can measure multidimensional mixture fraction under a wide range of flame conditions. A laser diagnostic technique based on photodissociation spectroscopy (PDS) is proposed to address this need. This thesis describes the concept of the PDS-based diagnostic, reports its experimental demonstration in a non-premixed jet flame, and assesses its performance and applicable range. The two-photon laser induced fluorescence (TPLIF) technique used in conjugate with the PDS is analyzed numerically in line and planar imaging configuration.
The new mixture fraction imaging technique is centered around the creative use of photodissociation (PD) for …


Investigation Of Two-Phase Behavior In Capillary Evaporators With Liquid Core Visualization, Brian D'Entremont Aug 2011

Investigation Of Two-Phase Behavior In Capillary Evaporators With Liquid Core Visualization, Brian D'Entremont

All Dissertations

The Capillary Pumped Loop (CPL) and Loop Heat Pipe (LHP) are thermal management devices which are high performance derivatives of the conventional heat pipe. Both consist of a discrete evaporator containing a porous solid wick which is coupled via smoothed walled tubing to a condenser. In a CPL, fluid inventory is managed by a reservoir attached to the liquid line which is controlled in temperature. In an LHP, fluid inventory is managed passively by a compensation chamber which is integral to the evaporator.
In this study, a borescope was inserted into the liquid core and compensation chamber of LHP evaporators …


Progressive Damage In Stitched Composites Under Impact Loading, Kwek Tze Tan, N. Watanabe, A. Yoshimura, Y. Iwahori, T. Ishikawa Aug 2011

Progressive Damage In Stitched Composites Under Impact Loading, Kwek Tze Tan, N. Watanabe, A. Yoshimura, Y. Iwahori, T. Ishikawa

Mechanical Engineering Faculty Research

Damage in carbon fibre reinforced plastics (CFRP) due to impact loading is an extremely complex phenomenon that comprises of multiple failure mechanisms like intra-laminar matrix cracks, interlaminar delamination, fibre pull-out and fibre fracture. In stitched composites, impact damage behavior is further complicated by the presence of through-thickness stitching [1, 2], which not only favorably increases mode I/II interlaminar strength [3, 4], but also inevitably creates geometrical defects like weak resin-rich pockets around stitch threads and misalignment of in-plane fibres. Computational modeling has been used to simulate progressive damage effectively [5]. However, the complexity of impact damage progression in stitched composites …


Design Optimization Using Cad Parameterization Through Capri, William Emerson Brock V Aug 2011

Design Optimization Using Cad Parameterization Through Capri, William Emerson Brock V

Masters Theses and Doctoral Dissertations

Design optimization is one of the many areas of Computational Engineering that is directly applicable to almost any engineering endeavor. The design cycle is a multi-step process, beginning with a Computer Aided Design (CAD) model and ending with an optimized version of that model relative to some objective function. This is accomplished by parameterizing the model, through one of many different algorithms, and finding the ideal value of those parameters with respect to the specified objective. The purpose of this research is to explore the use of a Computational Analysis PRogramming Interface (CAPRI) for utilizing CAD parameters in design optimization …


An Adaptive Hybrid Mesh Generation Method For Complex Geometries, Cameron Thomas Druyor Aug 2011

An Adaptive Hybrid Mesh Generation Method For Complex Geometries, Cameron Thomas Druyor

Masters Theses and Doctoral Dissertations

An adaptive hybrid mesh generation method is described to automatically provide spatial discretizations suitable for computational fluid dynamics or other 2D solver applications. This method employs a hierarchical grid generation technique to create a background mesh, an extrusion-type method for inserting boundary layers, and an unstructured triangulation to stitch between the boundary layers and background mesh. This method provides appropriate mesh resolution based on geometry segments from a file, and has the capability of adapting the background mesh based on a spacing field generated from solution data or some other arbitrary source. By combining multiple approaches to the grid generation …


Hardware Thread Management Modeling For Precision Timed Processors, David Edward Norwood Aug 2011

Hardware Thread Management Modeling For Precision Timed Processors, David Edward Norwood

Masters Theses and Doctoral Dissertations

Studies recently and currently in progress address timing demands for Cyber Physical Systems (CPS) applications. Certain areas of research seek to modify modern computer architecture to meet the needs of CPS applications. Moreover, specific modifications in current computer architecture have produced newer computer architectures and processors, such as precision timed (PRET) processors. This thesis focuses on identifying, modeling, and simulating thread management methods in hardware used by the current open-source PRET soft processor, the MultiFire.


Design Of A Uniform Circular Phased-Array Smart Antenna For 2.4 Ghz Applications, Hemasri Kollipara Aug 2011

Design Of A Uniform Circular Phased-Array Smart Antenna For 2.4 Ghz Applications, Hemasri Kollipara

Electrical Engineering Theses

An antenna is a transitional structure between free-space and a guiding device. Different types of antennas have different properties in terms of its radiation characteristics, directivity and gain. One of the antennas, which play an important role in advanced wireless communication systems, is the smart antenna. One of the most remarkable properties of a smart antenna is that it is capable of directing its main beam towards the direction of the individual user and the nulls in the direction of interfering signals. There are different configurations for smart antennas. One of these configurations is the Uniform Circular Array Antenna (UCA). …


A Study Of Multiprocessor Systems Using The Picoblaze 8-Bit Microcontroller Implemented On Field Programmable Gate Arrays, Venkata Mandala Aug 2011

A Study Of Multiprocessor Systems Using The Picoblaze 8-Bit Microcontroller Implemented On Field Programmable Gate Arrays, Venkata Mandala

Electrical Engineering Theses

As Field Programmable Gate Arrays (FPGAs) are becoming more capable of implementing complex logic circuits, designers are increasingly choosing them over traditional microprocessor-based systems for implementing digital controllers and digital signal processing applications. Indeed, as FPGAs are being built using state-of-the-art deep submicron CMOS processes, the increased amount of logic and memory resources allows such FPGA-based implementations to compete in terms of speed, complexity, and power dissipation with most custom-built chips, but at a fraction of the development costs. The modern FPGA is now capable of implementing multiple instances of configurable processors that are completely specified by a high-level descriptor …


Implementation Of A Full Doppler Compensation To Eliminate The Use Of First Order Approximation To Compensate The Doppler In Large Time-Bandwith Product Radar Images, Pavan Vutukur Aug 2011

Implementation Of A Full Doppler Compensation To Eliminate The Use Of First Order Approximation To Compensate The Doppler In Large Time-Bandwith Product Radar Images, Pavan Vutukur

Electrical Engineering Theses

The First Order Approximation technique is used in current generation of radars to compensate for the frequency shift due to the target's velocity. A common practice in radar systems to improve their resolution and performance is to increment the Time-Bandwidth (TBW) product of the transmitted signal. As the first order approximation is comprised of only the first two terms of a power series expansion; any significant increase in the TBW product of the signal results in significant errors in the radar image. In this research, the full Doppler compensation methodology was implemented and compared to the common approximation. The Time-Bandwidth …


A Three-Dimensional Hydro-Environmental Model Of Dublin Bay, Zeinab Bedri, Michael Buen, Aodh Dowley Aug 2011

A Three-Dimensional Hydro-Environmental Model Of Dublin Bay, Zeinab Bedri, Michael Buen, Aodh Dowley

Articles

This paper compares a 3-dimensional hydro-ecological model with a 2-dimensional model simulating the distribution and fate of Escherichia Coli (E.Coli) discharges from a sewage treatment plant discharging into Dublin Bay, Ireland. Before being discharged, the effluent from the sewage treatment plant is mixed with cooling water from a thermal generation plant resulting in a warm buoyant sewage plume that can be 7 − 9oC higher than the ambient water in the Bay. The mixing of the stratified plume is complicated by the tidal currents which transport the plume into and out of the estuary. These processes have a direct impact …


Packaging Strategy For High Voltage And High Shock Environments, Kevin Austin Aug 2011

Packaging Strategy For High Voltage And High Shock Environments, Kevin Austin

Mechanical Engineering Student Publications

The historical design approach for ensuring survivability in devices that operate at high voltages which would arc in air or that must survive substantial shock loadings employs an encapsulant whose dielectric strength prevents electrical breakdown and whose modulus prevents gross movement of the embedded components. While mostly successful, this approach presents some significant design challenges: (1) the high thermal expansion of the epoxy leads to large stresses during thermal cycles, (2) degassing of the epoxy before cure and careful encapsulation are essential to eliminate voids that could initiate dielectric breakdown, (3) the internal components are embedded deep within an impenetrable …


Enhancing The Performance Of Building Integrated Photovoltaics, Brian Norton, Philip C. Eames, Tapas K. Mallick, Ming Jun Huang, Sarah J. Mccormack, Jayanta D. Mondol, Yigzaw G. Yohanis Aug 2011

Enhancing The Performance Of Building Integrated Photovoltaics, Brian Norton, Philip C. Eames, Tapas K. Mallick, Ming Jun Huang, Sarah J. Mccormack, Jayanta D. Mondol, Yigzaw G. Yohanis

Articles

Recent research in Building Integrated Photovoltaics (BIPV) is reviewed with the emphases on a range of key systems whose improvement would be likely to lead to improved solar energy conversion efficiency and/or economic viability. These include invertors, concentrators and thermal management systems. Advances in techniques for specific aspects of systems design, installation and operation are also discussed.


Improving Intersection Design Practices, Nikiforos Stamatiadis, Adam Kirk, Nithin Agarwal, Chris Jones Aug 2011

Improving Intersection Design Practices, Nikiforos Stamatiadis, Adam Kirk, Nithin Agarwal, Chris Jones

Kentucky Transportation Center Research Report

The purpose of this report is to document the development of the Intersection Design Alternative Tool (IDAT) developed for the Kentucky Transportation Cabinet. IDAT provides an automated objective design and evaluation approach of 14 alternative intersection designs to assist in the conceptual design of at-grade intersections. The tool evaluates intersection operations, safety performance, bicycle/pedestrian accommodation and has the ability to assist access management implementation.


2011 Safety Belt Usage Survey In Kentucky, Eric R. Green, Kenneth R. Agent Aug 2011

2011 Safety Belt Usage Survey In Kentucky, Eric R. Green, Kenneth R. Agent

Kentucky Transportation Center Research Report

EXECUTIVE SUMMARY

The objective of this study was to establish 2011 safety belt and child safety seat usage rates in Kentucky . The 2011 survey continues to document the results after enactment of the original “secondary enforcement” statewide mandatory safety belt law in 1994 and the subsequent change to “primary enforcement” which was enacted in 2 006. Data were collected at 160 randomly selected sites in 18 counties across Kentucky. Data from the individual sites were combined into a statewide percentage considering roadway functional classification, county, and vehicle miles traveled.

The data show that the usage rate in 2011 (82.2 …


Articulated Mechanism Design And Kinematics For Natural Orifice Translumenal Endoscopic Surgery Robot, Wei Jian Chin Aug 2011

Articulated Mechanism Design And Kinematics For Natural Orifice Translumenal Endoscopic Surgery Robot, Wei Jian Chin

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Natural Orifice Translumenal Endoscopic Surgery (NOTES) is a fairly recent surgical approach that eliminates the need for external incisions on the patient. NOTES takes the minimally invasive surgery paradigm a step further by using a natural orifice as the pathway to transport surgical tools to the surgical site and completely eliminating the need for even the smallest incision on the skin. Although the concept of NOTES has been in existence for the past decade, technological deficiencies prevent it from being widely accepted in human surgeries. A novel multifunctional robot for NOTES has been developed to overcome these limitations and make …


Classification For Mass Spectra And Comprehensive Two-Dimensional Chromatograms, Xue Tian Aug 2011

Classification For Mass Spectra And Comprehensive Two-Dimensional Chromatograms, Xue Tian

School of Computing: Dissertations, Theses, and Student Research

Mass spectra contain characteristic information regarding the molecular structure and properties of compounds. The mass spectra of compounds from the same chemically related group are similar. Classification is one of the fundamental methodologies for analyzing mass spectral data. The primary goals of classification are to automatically group compounds based on their mass spectra, to find correlation between the properties of compounds and their mass spectra, and to provide a positive identification of unknown compounds.

This dissertation presents a new algorithm for the classification of mass spectra, the most similar neighbor with a probability-based spectrum similarity measure (MSN-PSSM). Experimental results demonstrate …


The Effects Of Retrogression And Reaging On Aluminum Alloy 2099 (C458), N. Ward, A. Tran, A. Abad, E. W. Lee, M. Hahn, E. Fordan, Omar S. Es-Said Aug 2011

The Effects Of Retrogression And Reaging On Aluminum Alloy 2099 (C458), N. Ward, A. Tran, A. Abad, E. W. Lee, M. Hahn, E. Fordan, Omar S. Es-Said

Mechanical Engineering Faculty Works

The objective of this study was to investigate the feasibility of performing retrogression and reaging (RRA) heat treatments on 2099 aluminum-lithium alloy. The retrogression temperatures were 200-250 A degrees C and retrogression times were 5-60 min. Half of the samples were exposed to a salt fog environment. Interestingly, the samples exposed to salt spray had consistently higher mechanical tensile properties than those which were not exposed.


Owl And Rules, Adila Krisnadhi, Frederick Maier, Pascal Hitzler Aug 2011

Owl And Rules, Adila Krisnadhi, Frederick Maier, Pascal Hitzler

Computer Science and Engineering Faculty Publications

The relationship between the Web Ontology Language OWL and rule-based formalisms has been the subject of many discussions and research investigations, some of them controversial. From the many attempts to reconcile the two paradigms, we present some of the newest developments. More precisely, we show which kind of rules can be modeled in the current version of OWL, and we show how OWL can be extended to incorporate rules. We finally give references to a large body of work on rules and OWL.


Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn Aug 2011

Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn

Electrical Engineering

As the demand for more devices to become wireless increases, there is a need for linear, efficient monolithic power amplifiers to deal with the variations in modulation of signals. With partial support from Cal Poly C3RP Grant #52268, this paper explains the implementation of and analyzes a circuit that actively biases a bipolar transistor to operate as a Class C amplifier. The Class C amplifier can maintain constant conduction angle over a range of output powers by using a Class B amplifier to force a scaled DC current vs. input magnitude curve on to a Class C amplifier. The knee …


Thermal Expansions In Wurtzite Aln, Gan, And Inn: First-Principle Phonon Calculations, L.-C. Xu, R.-Z. Wang, Xiaodong Yang, H. Yan Aug 2011

Thermal Expansions In Wurtzite Aln, Gan, And Inn: First-Principle Phonon Calculations, L.-C. Xu, R.-Z. Wang, Xiaodong Yang, H. Yan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using the first-principle phonon calculations under the quasiharmonic approximation, thermal expansions in III-nitrides with wurtzite AlN, GaN, and InN are reported. The results showed that it is different for each thermal expansion of three III-nitrides at low temperatures, which is consistent with their Grneisen parameters as the function of temperature. Below 50 K, negative thermal expansions occur in InN, while GaN and AlN follow the rule of positive thermal expansion. To seek the origin of positivenegative thermal expansion distinction, the mode Grneisen parameters and the phonon spectra are investigated. They indicate that different low-frequency phonon vibration modes correspond to the …


Online Optimal Control Of Nonlinear Discrete-Time Systems Using Approximate Dynamic Programming, Travis Dierks, Sarangapani Jagannathan Aug 2011

Online Optimal Control Of Nonlinear Discrete-Time Systems Using Approximate Dynamic Programming, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the optimal control of a class of general affine nonlinear discrete-time (DT) systems is undertaken by solving the Hamilton Jacobi-Bellman (HJB) equation online and forward in time. the proposed approach, referred normally as adaptive or approximate dynamic programming (ADP), uses online approximators (OLAs) to solve the infinite horizon optimal regulation and tracking control problems for affine nonlinear DT systems in the presence of unknown internal dynamics. Both the regulation and tracking controllers are designed using OLAs to obtain the optimal feedback control signal and its associated cost function. Additionally, the tracking controller design entails a feedforward portion …


Computational Analysis Of The Dynamic Forces In Drive Train Components Of An Offshore Wind Turbines, Artem Korobenko Aug 2011

Computational Analysis Of The Dynamic Forces In Drive Train Components Of An Offshore Wind Turbines, Artem Korobenko

All Theses

Wind has good potential for contributing to the national energy supply. Offshore sites and deep sea locations can be especially attractive as the wind turbine market grows. In such places larger wind resources are available with reduced turbulence intensity and wind shear. In addition, visual impact along with noise aspects are reduced. Offshore siting requires greater attention to structural stability and endurance. Forces on drive train components, such as the bearing system, are not well understood.
This work presents the development a model that calculates dynamical forces in drive train components of off-shore wind turbines. The model of a 5MW …


Understanding The Role Of Functions And Interactions In The Product Design, Raveesh Ramachandran Aug 2011

Understanding The Role Of Functions And Interactions In The Product Design, Raveesh Ramachandran

All Theses

Engineering designers often generate design concepts based on a functional understanding of the problem. Many engineering textbooks encourage designers to abstract the essential problem to a higher-level functional representation of the product and subsequently develop solutions to the functional needs. However, a functional perspective of design does not provide a complete view of what the product must do and how the product must interact with users and other parts. To address this, an alternative modeling approach has been developed to complement the traditional functional modeling approaches. Two such approaches include (1) activity modeling to capture the user actions from production …


Cfd Analysis Of The Under Hood Of A Car For Packaging Considerations, Sreekanth Reddy Gondipalle Aug 2011

Cfd Analysis Of The Under Hood Of A Car For Packaging Considerations, Sreekanth Reddy Gondipalle

All Theses

In recent years, there has been an increase in demand towards the improvement of car design for achieving better performance and increasing passenger comfort. Improving the design of individual components to meet the customer needs for improved vehicle performance alone is not enough. Interactions of these components with the surrounding components and their placement should also be investigated. Placement of these components in the under hood space forms a 3-Dimensional packaging problem. In the past, a multi objective optimization process was setup to determine the optimal placement of these components in the car under hood space. Three main objectives were …


Design, Construction And Evaluation Of Seven Shank, Three Point Ripper, Daniel Degraaf Aug 2011

Design, Construction And Evaluation Of Seven Shank, Three Point Ripper, Daniel Degraaf

BioResource and Agricultural Engineering

This senior project discusses the design, construction, and testing of a seven shank, three point ripper built for de Graaf Ranch. This ripper will replace older equipment that was not built to withstand the horsepower developed by more modern tractors that are used by de Graaf Ranch. This tillage device is designed to meet ASABE standards for horsepower requirements of farm equipment. This implement incorporates a shear pin design that will protect the frame from damage in the event that the ripper encounters a subsoil obstacle that would significantly damage the equipment. The shank was designed to reduce the disturbance …


Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang Aug 2011

Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang

Electrical Engineering

This project tests and analyzes the efficiency of directional and omnidirectional antennas in wireless power transfer for charging. The project demonstrates the steps of construction and properties of dipole, monopole, and Yagi Uda antennas. A low power high frequency DC rectifier circuit converts the received RF power from the antenna and stored it as DC voltage on a capacitor. The receiver circuit also estimates the power received by the antenna. Wireless RF power transmission proves to be inefficient for short distances. The best efficiencies of the antennas were under 50% even at 0.1meter. The near field attenuation starts at around …


140 New Montgomery Power Distribution Design, Stephen Shaffer Aug 2011

140 New Montgomery Power Distribution Design, Stephen Shaffer

Electrical Engineering

The Power Distribution Design for a high-rise building requires a great deal of coordination and design from the structural, electrical, mechanical, telecommunication, and PG&E engineers. This report will cover how I was able to coordinate and design the power distribution system for 140 New Montgomery, a 28 story building located in San Francisco. Furthermore, this report will cover the steps taken in the future to ensure a smooth transition from the schematic design phase to the construction document phase.