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2009

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Articles 1051 - 1080 of 4158

Full-Text Articles in Engineering

A Method For Accounting For Pile Setup And Relaxation In Pile Design And Quality Assurance, Prasenjit Basu, Rodrigo Salgado, Monica Prezzi, Tanusree Chakraborty Aug 2009

A Method For Accounting For Pile Setup And Relaxation In Pile Design And Quality Assurance, Prasenjit Basu, Rodrigo Salgado, Monica Prezzi, Tanusree Chakraborty

JTRP Technical Reports

When piles are installed by jacking or driving, they cause substantial changes in the state of soil located near the pile. These changes result from the complex loading imposed on the soil by expansion of a cylindrical cavity to make room for the pile, by multiple cycles of shearing in the vertical direction as the pile gradually moves down into the ground, and by the slow drainage associated with clayey soils. If a pile is load-tested a short time after installation, it will develop an axial resistance that reflects the existence in the soil of the excess pore pressures caused …


Origin-Destination Tools For District Offices, Jon D. Fricker, Maria Martchouk Aug 2009

Origin-Destination Tools For District Offices, Jon D. Fricker, Maria Martchouk

JTRP Technical Reports

Understanding through trip patterns is crucial when making decisions concerning a traffic diversion strategy, such as whether to build a highway to bypass a city. While conducting a vehicle license plate origin-destination survey may be the most accurate way to estimate through trip patterns, many small communities may be unable to bear this cost. Thus, a simple and affordable sketch planning tool to estimate through trip movements would be useful. Three through trip estimation methods that have been used or published are Modlin’s method, Anderson’s method, and subarea analysis. Subarea analysis, while an effective tool, requires personnel with knowledge of …


Frp Confined Reinforced Concrete Circular Cross Section Seismic Applications, Jeffrey G. Lyon Aug 2009

Frp Confined Reinforced Concrete Circular Cross Section Seismic Applications, Jeffrey G. Lyon

Master's Theses

In recent earthquakes, structures have not performed as well as expected resulting in a need for better means of retrofitting and improvements in seismic design. Fiber Reinforced Polymers (FRP), as a material with potential to increase strength and ductility of columns in conjunction with capacity design methodology, has promise for seismic design. By investigating the displacement, ductility, and flexural strength properties of FRP confined reinforced concrete circular cross sections, this study analyzes the seismic applications of FRP confinement.

The study is performed by incorporating an FRP confined concrete stress-strain model into a developed Moment-Curvature and PM Interaction software. This software …


Nano-Surface Engineering On Copper Substrate For Friction Reduction, Julius Morehead Aug 2009

Nano-Surface Engineering On Copper Substrate For Friction Reduction, Julius Morehead

Mechanical Engineering Undergraduate Honors Theses

Nano-engineered-textures on a material surface used to conduct fluids can significantly improve the hydrophobicity or wetting property of the surface, resulting in lower resistance of the surface to the fluid?s movement. In this work, aluminum-induced crystallization of amorphous silicon was investigated for generating nano-textures on copper substrates, a common material in heating, ventilating, air conditioning, and refrigeration systems. Flat copper substrate was utilized. Several experiments were conducted to study the effects of annealing temperature, annealing duration, a-Si and Al thickness, and the sequence of film structure. Scanning electron microscopy was employed to characterize the surface nano-topography. The results showed that …


Review Construction Techniques For Accelerated Construction And Cost Implications, Joo Hyoung (Jay) Lee, Bob G. Mccullouch Aug 2009

Review Construction Techniques For Accelerated Construction And Cost Implications, Joo Hyoung (Jay) Lee, Bob G. Mccullouch

JTRP Technical Reports

Transportation construction activities on heavy traffic routes can be very disruptive to the system users due to lane closures, construction traffic, or reduced speed zones. Besides the driving public, local businesses are also affected by noise and air pollution, loss of access, or changing access routes. Thus, it is apparent that minimizing construction time will lessen these impacts. The primary objectives of this project are to explore some alternative methods to expedite construction time for particular project types whereby mitigating disruptions to the traveling public and to identify construction activities that can be accelerated by those selected methods. To accomplish …


A Novel Tdr-Based Coaxial Cable Sensor For Crack/Strain Sensing In Reinforced Concrete Structures, Shishuang Sun, David Pommerenke, James L. Drewniak, Genda Chen, Liang Xue, Michael A. Brower, Marina Koledintseva Aug 2009

A Novel Tdr-Based Coaxial Cable Sensor For Crack/Strain Sensing In Reinforced Concrete Structures, Shishuang Sun, David Pommerenke, James L. Drewniak, Genda Chen, Liang Xue, Michael A. Brower, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Novel coaxial cable sensors that feature high sensitivity and high spatial resolution are developed for health monitoring of concrete structures using a time-domain reflectometry (TDR). The new sensor was designed based on the topology change of its outer conductor, which was fabricated with tightly wrapped commercial tin-plated steel spiral covered with solder. The cracks that developed within concrete structures will lead to out-of-contact of local steel spirals. This topology change results in a large impedance discontinuity that can be measured with a TDR. A simplified equivalent transmission line model and numerical full-wave simulations using finite-difference time-domain techniques were used to …


Handbook For Temporary Traffic Control - Construction, Maintenance, And Utility Operations, Indiana Ltap Aug 2009

Handbook For Temporary Traffic Control - Construction, Maintenance, And Utility Operations, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This handbook gives the basic principles and provides examples for the design, application, installation, and maintenance of the various types of traffic control devices used in temporary traffic control or for incident management. The guidelines presented are in accordance with the standards provided within the Indiana Manual for Uniform Traffic Control Devices (IMUTCD). This handbook is based upon one created by the Ohio Department of Transportation, Guidelines for Traffic Control in Work Zones. Indiana LTAP expresses thanks to ODOT for their permission to reprint this material.


The Implementation And Analysis Of Through Wall Radar Systems, Xiaohui Wang Aug 2009

The Implementation And Analysis Of Through Wall Radar Systems, Xiaohui Wang

Theses and Dissertations - UTB/UTPA

Through wall radar detecting, locating, imaging and tracking is a topic of current research interest in connection with law enforcement, urban area operations and search and rescue missions. Up to now, three different radar techniques are employed in through wall radar systems, including impulse through wall radar, continuous wave radar and swept frequency radar. In this thesis, we set out to give a comparison of these three kinds of through wall radar systems. First,we studied the challenges caused by the wall in through wall radar systems. Second,we implemented these three kinds of through wall radar system. In each kind of …


Asynchronous Designs On Fpga With Soft Error Tolerance For Security Algorithms, Deepya Reddy Nalubolu Aug 2009

Asynchronous Designs On Fpga With Soft Error Tolerance For Security Algorithms, Deepya Reddy Nalubolu

Theses and Dissertations - UTB/UTPA

Asynchronous methodologies, such as Null Convention Logic (NCL), have tremendous potential in implementing digital logic. It is essential to design complex asynchronous circuits using commercial Electronic Design Automation (EDA) tools. The main focus of this thesis is to design NCL circuits using VHDL and implementing them on FPGAs. The major contributions of this thesis include: 1) Developing a methodology of designing NCL circuits with VHDL and applying it successfully to all practical designs in this thesis. 2) As an example, the NCL circuit for DES (Data Encryption Standard) algorithm has been designed and simulated using VHDL and the implementation issues …


Methods And Challenges Of Experimental System Identification Of A Distillation Column, Marc Christopher Moss Aug 2009

Methods And Challenges Of Experimental System Identification Of A Distillation Column, Marc Christopher Moss

Masters Theses and Doctoral Dissertations

University of Tennessee at Chattanooga Engineering Department distillation column is used as a teaching tool, but is currently without a feedback control system. An eventual goal of developing such a control system requires that the behavior of the column be understood. It is necessary to identify which of the column parameters can change, either ones that change to cause a disturbance, or ones that the controller can change in response to a disturbance. There are four of these parameters in the UTC column: feed flow rate, feed composition, reboiler heat and reflux percent. Experiments were performed on the column to …


Effect Of Harmonics On The Efficiency Of A Three Phase Energy Efficient And Standard Motors, Oladokun E. Faduyile Aug 2009

Effect Of Harmonics On The Efficiency Of A Three Phase Energy Efficient And Standard Motors, Oladokun E. Faduyile

Masters Theses and Doctoral Dissertations

This study investigates the impact of harmonics on the performance, efficiency, and the economics of energy efficient motors (EEMs) and standard motors (STMs). In this research, the skin effect impedance model that incorporates the skin effect in the rotor bars is used to study the motor’s behavior under harmonics. The characteristic behavior of the motors are simulated using a computer program which compares the performance, efficiency, and the economics of these motors and identifies the harmonic level at which these behavior are most prominent. The following motor sizes 25, 50, 100, 150, 200, 250, and 300 hp are used in …


Removal Of Boron From Produced Water By Co-Precipitation / Adsorption For Reverse Osmosis Concentrate, Imran Yusuf Rahman, Yarrow Nelson, Tryg Lundquist Aug 2009

Removal Of Boron From Produced Water By Co-Precipitation / Adsorption For Reverse Osmosis Concentrate, Imran Yusuf Rahman, Yarrow Nelson, Tryg Lundquist

Master's Theses

Co-precipitation and absorption methods were investigated for removal of boron from produced water, which is groundwater brought to the surface during oil and natural gas extraction. Boron can be toxic to many crops and often needs to be controlled to low levels in irrigation water. The present research focused on synthetic reverse osmosis (RO) concentrate modeled on concentrate expected from a future treatment facility at the Arroyo Grande Oil Field on the central coast of California. The produced water at this site is brackish with a boron concentration of 8 mg/L and an expected temperature of 80°C. The future overall …


Chip-Scale Nanophotonic Chemical And Biological Sensors Using Cmos Process, Lincoln Bollschweiler, Alex English, R. Jacob Baker, Wan Kuang, Zi-Chang Chang, Ming-Hsiung Shih, William Knowlton Aug 2009

Chip-Scale Nanophotonic Chemical And Biological Sensors Using Cmos Process, Lincoln Bollschweiler, Alex English, R. Jacob Baker, Wan Kuang, Zi-Chang Chang, Ming-Hsiung Shih, William Knowlton

Electrical and Computer Engineering Faculty Publications and Presentations

A monolithic integrated chip-scale surface plasmon resonance (SPR) sensor is demonstrated. The device consists of a pn photodiode covered with a periodic modified thin metal film whose lattice constant is on the order of the wavelength of light. The device performs real-time measurement of resonant wavelengths of enhanced optical transmission due to surface plasmon resonance, which are influenced by the presence of chemical or biological materials at the device’s surface.


Determining Azimuthal Variations In Frontal Froude Number From Sar Imagery, Jiayi Pan, David A. Jay, Hui Lin Aug 2009

Determining Azimuthal Variations In Frontal Froude Number From Sar Imagery, Jiayi Pan, David A. Jay, Hui Lin

Civil and Environmental Engineering Faculty Publications and Presentations

River plume fronts are the locus of strong mixing between plume and ambient coastal waters, contribute to coastal productivity, and exert a major impact on coastal ecosystems. The frontal Froude number Fr is an important parameter characterizing the frontal status with respect to both propagation and vertical mixing. In this study, we examine azimuthal variations in Fr using a new remote sensing method. We derive Fr from SAR image data on the basis of the SAR imaging theory and the mechanism of internal wave fission at front. This method is applied to a SAR image showing a front off the …


Randomcast: An Energy-Efficient Communication Scheme For Mobile Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das Aug 2009

Randomcast: An Energy-Efficient Communication Scheme For Mobile Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das

Electrical and Computer Engineering Faculty Publications

In mobile ad hoc networks (MANETs), every node overhears every data transmission occurring in its vicinity and thus, consumes energy unnecessarily. However, since some MANET routing protocols such as dynamic source routing (DSR) collect route information via overhearing, they would suffer if they are used in combination with 802.11 PSM. Allowing no overhearing may critically deteriorate the performance of the underlying routing protocol, while unconditional overhearing may offset the advantage of using PSM. This paper proposes a new communication mechanism, called RandomCast, via which a sender can specify the desired level of overhearing, making a prudent balance between energy and …


Use Of Orthogonal Arrays For Efficient Evaluation Of Geometric Designs For Reducing Vibration Of A Non-Pneumatic Wheel During High-Speed Rolling, William Rutherford Aug 2009

Use Of Orthogonal Arrays For Efficient Evaluation Of Geometric Designs For Reducing Vibration Of A Non-Pneumatic Wheel During High-Speed Rolling, William Rutherford

All Theses

During high speed rolling of a non-pneumatic wheel, vibration may be produced by the interaction of collapsible spokes with a shear deformable ring as they enter the contact region, buckle and then snap back into a state of tension. In the present work, a 2D planar finite element model with geometric nonlinearity and explicit time-stepping is used to simulate rolling of the non-pneumatic wheel. Vibration characteristics are measured from the FFT frequency spectrum of the time-signals of perpendicular distance of marker nodes from the virtual plane of the spoke, thickness change in the ring between spokes, and ground reaction forces. …


Development Of A Rigid Ring Tire Model And Comparison Among Various Tire Models For Ride Comfort Simulations, Norm Frey Aug 2009

Development Of A Rigid Ring Tire Model And Comparison Among Various Tire Models For Ride Comfort Simulations, Norm Frey

All Theses

One vehicle subassembly that is of great importance to automobile manufacturers for tuning final vehicle performance is the pneumatic tire. Pneumatic tires present themselves as unique tuning tools as they 1) are the sole link between the roadway surface and the integrated vehicle suspension, chassis and steering systems, and 2) provide a wide range of tunability over many vehicle performances, including handling (steering feel as well as chassis dynamics), traction (braking, driving, and cornering), and ride comfort (roadway isolation). Therefore the vehicle manufacturing industry continues to research and refine various aspects of tire modeling to improve up-front integrated tire/vehicle CAE/CAD …


Implementation Of Genetic Algorithms In Fpga-Based Reconfigurable Computing Systems, Nahid Alam Aug 2009

Implementation Of Genetic Algorithms In Fpga-Based Reconfigurable Computing Systems, Nahid Alam

All Theses

Genetic Algorithms (GAs) are used to solve many optimization problems in science and engineering. GA is a heuristics approach which relies largely on random numbers to determine the approximate solution of an optimization problem. We use the Mersenne Twister Algorithm (MTA) to generate a non-overlapping sequence of random numbers with a period of 219937-1. The random numbers are generated from a state vector that consists of 624 elements. Our work on state vector generation and the GA implementation targets the solution of a flow-line scheduling problem where the flow-lines have jobs to process and the goal is to find a …


Synthesis Of Optimal Usage Of Available Aggregates In Highway Construction And Maintenance, Benjamin Skidmore Aug 2009

Synthesis Of Optimal Usage Of Available Aggregates In Highway Construction And Maintenance, Benjamin Skidmore

All Theses

The optimization of the available aggregates for highway construction and maintenance is vital both from an economic and environmental perspective. By not optimizing the aggregate supply project costs escalate as a simple response to supply and demand, and just as important the fact that aggregate is a natural resource and a limited one, it is crucial that is used as efficiently as possible. This paper examines specifically the use of aggregates by the South Carolina Department of Transportation, but can easily be adapted to any state. Through DOT and quarry surveys and an examination of aggregate gradation specifications it was …


Acceleration Of Spiking Neural Networks On Multicore Architectures, Rommel Jalasutram Aug 2009

Acceleration Of Spiking Neural Networks On Multicore Architectures, Rommel Jalasutram

All Theses

The human cortex is the seat of learning and cognition. Biological scale
implementations of cortical models have the potential to provide significantly more
power problem solving capabilities than traditional computing algorithms. The large
scale implementation and design of these models has attracted significant attention
recently. High performance implementations of the models are needed to enable such
large scale designs. This thesis examines the acceleration of the spiking neural network
class of cortical models on several modern multicore processors. These include the
Izhikevich, Wilson, Morris-Lecar, and Hodgkin-Huxley models. The architectures
examined are the STI Cell, Sun UltraSPARC T2+, and Intel Xeon …


A Dual Input Bidirectional Power Converter For Charging And Discharging A Phev Battery, Daniel Fain Aug 2009

A Dual Input Bidirectional Power Converter For Charging And Discharging A Phev Battery, Daniel Fain

All Theses

This thesis looks at a new design for a dual input bidirectional power converter (DIBPC) for charging and discharging a PHEV battery. The design incorporates a power factor correcting rectifier aimed at optimizing the battery charging efficiency from either a 120 VAC or 240 VAC source or discharging the battery to a usable AC voltage at 120 VAC. For simplicity and cost-effectiveness, the DIBPC is constructed using a standard IGBT 6-pack intended for motor control. The DIBPC is designed specifically to provide efficient operation with 120 VAC and 240 VAC inputs while achieving a very low THDI. The DIBPC also …


Accuracy And Multi-Core Performance Of Machine Learning Algorithms For Handwritten Character Recognition, Sumod Mohan Aug 2009

Accuracy And Multi-Core Performance Of Machine Learning Algorithms For Handwritten Character Recognition, Sumod Mohan

All Theses

There have been considerable developments in the quest for intelligent machines since the beginning of the cybernetics revolution and the advent of computers. In the last two decades with the onset of the internet the developments have been extensive. This quest for building intelligent machines have led into research on the working of human brain, which has in turn led to the development of pattern recognition models which take inspiration in their structure and performance from biological neural networks. Research in creating intelligent systems poses two main problems. The first one is to develop algorithms which can generalize and predict …


Survey Of Concurrent Engineering Environments And The Application Of Best Practices Towards The Development Of A Multiple Industry, Multiple Domain Environment, Jonathan Osborn Aug 2009

Survey Of Concurrent Engineering Environments And The Application Of Best Practices Towards The Development Of A Multiple Industry, Multiple Domain Environment, Jonathan Osborn

All Theses

This thesis investigates the best practices of fifteen existing Concurrent Engineering Environments (CEE). A CEE is defined as any environment, from physical to virtual, designed to facilitate concurrent engineering with multiple domain experts real time. All existing environments surveyed have been focused on the aerospace industry showing significant reductions in design time and cost. I have identified hardware, software, and peopleware as three major classifications as well as sixteen subcategories with which to compare the different CEEs. The success in reducing time and cost of designs seen in the aerospace industry with the introduction of CEEs can and should be …


The Characterization, Isolation, And Fractionation Of Natural Organic Matter From Three Surface Waters, Olivia Orr Aug 2009

The Characterization, Isolation, And Fractionation Of Natural Organic Matter From Three Surface Waters, Olivia Orr

All Theses

The main objective of this study was to gain insight to the principles of isolation of natural organic matter (NOM) using reverse osmosis (RO) and subsequent fractionation using resin adsorption chromatography (RAC). Specifically, this study evaluated the RO and RAC methods for NOM characterization from three surface waters with varying physiochemical characteristics. Efficiency of RO was assessed by closing mass balances for dissolve organic carbon (DOC). Mass balances were also closed for dissolved nitrogen (DN), bromide (Br-), nitrate (NO3-), total calcium (Ca), total potassium (K), total manganese (Mn), total iron (Fe), total magnesium (Mg), total aluminum (Al), total copper (Cu), …


Hydraulic Modeling To Inform Stream Maintenance Practices In South Carolina, Kelly Owens Aug 2009

Hydraulic Modeling To Inform Stream Maintenance Practices In South Carolina, Kelly Owens

All Theses

The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. Evidence of bank instability and inchannel erosion is widely seen in the Crabtree Canal system. Principal sediment inputs are landscape sources and in-channel sources. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by a hypothetical storm event and alternative channel configurations. The management tool comprised of a one-dimensional HEC-RAS model of the Crabtree Canal and was developed to aid the Horry County stormwater …


Operation Assessment Of Reservoirs In The Savannah River Basin, Travis Yates Aug 2009

Operation Assessment Of Reservoirs In The Savannah River Basin, Travis Yates

All Theses

Hydropower is generated from three reservoirs in the United States Army Corps of Engineer's Savannah District. These reservoirs include J. Strom Thurmond, Richard B. Russell, and Hartwell. Currently, a contract in place specifies that certain amount of energy must be provided to the region. The contract for the hydropower was based upon the critical hydrologic year of 1981. Historically, this was the most severe drought on record and assumed to provide the lowest net inflows for the three reservoirs, thus providing an attainable or reliable energy amount for the system, which suggests a dependable energy yield.
Reevaluating the contract amount …


The Effect Of Relative Humidity On The Microbial Barrier Properties Of Porous Packaging Materials Used In The Medical Device Industry, Jennifer Blocher Aug 2009

The Effect Of Relative Humidity On The Microbial Barrier Properties Of Porous Packaging Materials Used In The Medical Device Industry, Jennifer Blocher

All Theses

Porous packaging materials, such as medical-grade paper and Tyvek¨, are used often by the medical device industry for packaging sterile devices when the products are sterilized post packaging. Their use can be attributed to the fact that multiple sterilization methods require the ability for vapors to enter and/or exit the package efficiently, while simultaneously reducing the amount of microbes entering the package. Much research as been done to study the effects of multiple material and environmental factors, such as material structure and dispersion concentration, on the microbial barrier properties of these materials, however no research had been conducted to examine …


Dynamic Finite Element Simulation Of Ultrasonic Consolidation, Daniel Mccullough Aug 2009

Dynamic Finite Element Simulation Of Ultrasonic Consolidation, Daniel Mccullough

All Theses

Ultrasonic Consolidation (UC) is a promising solid state rapid manufacturing process that provides the ability to create functional, multilayered, and often geometrically complex parts. This thesis seeks to address one of the primary obstacles faced when using the process, namely the apparent build height limit encountered when using UC to construct high aspect ratio specimens. A fully transient, three dimensional Finite Element model is created to study the dynamic behavior of an ultrasonically consolidated part during the UC process. The model is used to find the cause of bond failure at the build height limit and a potential way to …


Effects Of Phase And Amplitude Errors On Qam Systems With Error-Control Coding And Soft Decision Decoding, Jason Ellis Aug 2009

Effects Of Phase And Amplitude Errors On Qam Systems With Error-Control Coding And Soft Decision Decoding, Jason Ellis

All Theses

Demodulation of M-ary quadrature amplitude modulation (M-QAM) requires the receiver to estimate the phase and amplitude of the received signal. The demodulator performance is sensitive to errors in these estimates, and the sensitivity increases as M increases. We examine the effects of phase and amplitude errors on the performance of QAM communication systems with error-control coding and soft-decision decoding. A mathematical analysis of these effects is presented for two soft-decision decoding metrics. Performance comparisons are given for 16-QAM and 64-QAM for two error-control coding techniques and two soft-decision decoding metrics.


Biohydrogen Production From Cull Peach Medium By Hyperthermophilic Bacterium Thermotoga Neapolitana, Abhiney Jain Aug 2009

Biohydrogen Production From Cull Peach Medium By Hyperthermophilic Bacterium Thermotoga Neapolitana, Abhiney Jain

All Theses

ABSTRACT
Thermotoga neapolitana is a marine hyperthermophilic bacterium that ferments various sugars to hydrogen and acetate. In this study, cull peaches were used as carbon source in a defined medium for biohydrogen production and produced 18 % to 25% hydrogen in the headspace. The hydrogen production varied from 6.4-7.7 mmol H2/g peach (dry weight). The hydrogen concentration did not increase after 20 hours of incubation. The final pH decreased to 4.9 after 20 hours. Unautoclaved peach medium can be used for hydrogen production. The hydrogen production did not increase with the increase in peach concentration from 50 g/L to 100 …