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2009

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Articles 1081 - 1110 of 4158

Full-Text Articles in Engineering

Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes Aug 2009

Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes

All Theses

An environmentally friendly method for the disposal of scrap tires is currently unavailable; as a result, ultimate disposal of used vehicle tires continues to be a major challenge around the world. In the United States (US), during the past two decades, scrap tires have been generated at the rate of approximately one tire per person per year (i.e., approximately 290 million new scrap tires every year). It is estimated that there are currently 2 billion tires stockpiled in the US. Due to various problems involved in the disposal of scrap tires, different alternatives for recycle and reuse have been examined; …


Predictive Energy Management In Smart Vehicles: Exploiting Traffic And Traffic Signal Preview For Fuel Saving, Behrang Asadi Aug 2009

Predictive Energy Management In Smart Vehicles: Exploiting Traffic And Traffic Signal Preview For Fuel Saving, Behrang Asadi

All Theses

This master thesis proposes methods for improving fuel economy and emissions of vehicles via use of future information of state of traffic lights, traffic flow, and deterministic traffic flow models.
The first part of this thesis proposes use of upcoming traffic signal information
within the vehicle's adaptive cruise control system to reduce idle time at stop lights and lower fuel use. To achieve this goal an optimization-based control algorithm is formulated for each equipped vehicle that uses short range radar and traffic signal information predictively to schedule an optimum velocity trajectory for the vehicle. The objectives are timely arrival at …


Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar Aug 2009

Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar

All Theses

A water quality modeling study was conducted to determine and compare nitrogen loss from agricultural systems growing switchgrass and cotton in the southeastern USA. The water quality impacts were modeled at the plot scale and at the watershed scale. The Soil and Water Assessment Tool (SWAT) was used to replicate field conditions observed at switchgrass research plots at Pee Dee Research and Educational Center at Florence, South Carolina. The plot scale modeling suggested that in the early years of growth there is significant nitrogen loss from switchgrass to streamflow and groundwater but they are significantly less as the switchgrass matures. …


Improving Open Canned Systems, David Sanders, Steven L. Barfuss, Michael C. Johnson Aug 2009

Improving Open Canned Systems, David Sanders, Steven L. Barfuss, Michael C. Johnson

Civil and Environmental Engineering Faculty Publications

The results of a study on the hydraulic performance of open-bottom canned pump intakes should aid engineers and pump users to design these systems with reduced velocity fluctuations and undesirable flow rotation.


Synthesis And Polymorphic Control For Visible Light Active Titania Nanoparticles, Sujaree Kaewgun Aug 2009

Synthesis And Polymorphic Control For Visible Light Active Titania Nanoparticles, Sujaree Kaewgun

All Dissertations

Titania (TiO2) is useful for many applications in photocatalysis, antimicrobials, pigment, deodorization, and decomposition of harmful organics and undesirable compounds in the air and waste water under UV irradiation. Among the three phases of TiO2, Rutile, Anatase, and Brookite, studies have been more focused on the anatase and rutile phases.
Pure brookite is the most difficult phase to prepare, even under hydrothermal conditions. Predominantly brookite phase TiO2 nanoparticles were prepared by the Water-based Ambient Condition Sol (WACS) process in our laboratory. The objectives of this research were to enhance visible light active (VLA) photocatalytic properties …


Development And Integration Of Geometric And Optimization Algorithms For Packing And Layout Design, Santosh Tiwari Aug 2009

Development And Integration Of Geometric And Optimization Algorithms For Packing And Layout Design, Santosh Tiwari

All Dissertations

The research work presented in this dissertation focuses on the development and application of optimization and geometric algorithms to packing and layout optimization problems. As part of this research work, a compact packing algorithm, a physically-based shape morphing algorithm, and a general purpose constrained multi-objective optimization algorithm are proposed. The compact packing algorithm is designed to pack three-dimensional free-form objects with full rotational freedom inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed compact packing algorithm can handle objects with holes or cavities and its performance does not degrade significantly with the increase in the complexity …


Moisture Susceptibility Of Asphalt Mixes Using Phosphonylated Recycled Polyethylene, David Herndon Aug 2009

Moisture Susceptibility Of Asphalt Mixes Using Phosphonylated Recycled Polyethylene, David Herndon

All Dissertations

ABSTRACT
Today's asphaltic concrete pavements are expected to perform better even though they are experiencing increased volume of traffic and increased loads over what has been experienced in the past. Research has indicated that the addition of polymers to asphalt binders can enhance many properties of the asphalt pavements to help meet these increased demands.
There remains a serious problem that the addition of polymers to asphalt binders generally does not address. This involves the interfacial cohesiveness of the bond between the aggregate and the binder. Some aggregates are highly hydrophilic (water-loving) while asphalt binders and most polymers tend to …


Novel Techniques For The Synthesis Of Three-Way Catalytic Converter Support Materials, Prince Anyaba Aug 2009

Novel Techniques For The Synthesis Of Three-Way Catalytic Converter Support Materials, Prince Anyaba

All Dissertations

Current automobiles use catalytic converters, consisting of noble metals on an oxide support, to convert noxious engine exhaust pollutants into less harmful species. The development of mesoporous oxide supports with optimal pore geometries could enable these devises to decrease in size and weight and significantly reduce the metal loadings required to achieve optimal performance. Thus, in this work, I investigated a wide range of techniques for the synthesis of mesoporous oxides to determine if they could be adapted to ceria-zirconia-yttria mixed oxide (CZY) systems, which are the industry standard for the optimal oxide support for catalytic converter applications. Additionally, I …


Creation Of Defined Single Cell Resolution Neuronal Circuits On Microelectrode Arrays, Russell Pirlo Aug 2009

Creation Of Defined Single Cell Resolution Neuronal Circuits On Microelectrode Arrays, Russell Pirlo

All Dissertations

The way cell-cell organization of neuronal networks influences activity and facilitates function is not well understood. Microelectrode arrays (MEAs) and advancing cell patterning technologies have enabled access to and control of in vitro neuronal networks spawning much new research in neuroscience and neuroengineering. We propose that small, simple networks of neurons with defined circuitry may serve as valuable research models where every connection can be analyzed, controlled and manipulated.
Towards the goal of creating such neuronal networks we have applied microfabricated elastomeric membranes, surface modification and our unique laser cell patterning system to create defined neuronal circuits with single-cell precision …


Lyapunov-Based Coordinated Control Of An Underactuated Unmanned Aerial Vehicle And Robot Manipulator, Dongbin Lee Aug 2009

Lyapunov-Based Coordinated Control Of An Underactuated Unmanned Aerial Vehicle And Robot Manipulator, Dongbin Lee

All Dissertations

This Ph.D. dissertation describes nonlinear tracking control results for a quadrotor helicopter unmanned aerial vehicle (UAV) towards the ultimate goal of controlling a combined UAV plus robot manipulator system (UAVRM). The quadrotor UAV is a helicopter that has four independent rotors that provide vertical lift: these four independent forces are managed in order to directly provide lift, pitch, roll, and yaw of the vehicle. Horizontal translations result from pitch and roll actions, the system is underactuated in the sense that there are only four control inputs to move the six degree-of-freedom aircraft. There are exising dynamic models of the quadrotor …


Gain Saturation In Gain-Guided Slab Waveguides With Large-Index Antiguiding, Tsing-Hua Her, Xianyu Ao, Lee W. Casperson Aug 2009

Gain Saturation In Gain-Guided Slab Waveguides With Large-Index Antiguiding, Tsing-Hua Her, Xianyu Ao, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

We investigate numerically and analytically the effects of gain saturation on the propagation of the fundamental mode in a gain-guided index-antiguided slab waveguide. The propagating mode adapts to gain saturation by becoming less confined, while at the same time its peak intensity increases more slowly. At steady state, both the mode shape and the power remain constant.


The Tromped, A Means Of Prophylaxis For Flight Related Deep Vein Thrombosis, Carolyn Collins Aug 2009

The Tromped, A Means Of Prophylaxis For Flight Related Deep Vein Thrombosis, Carolyn Collins

Doctoral

The process of blood flow in the leg, against gravity and towards the heart is instigated by compression of the veins in the foot. Contraction of the calf muscles results in an ejection volume (EV) of blood towards the heart, completing the process. Research studies have shown an association between flight travel and deep vein thrombosis (DVT). Stasis of blood flow can lead to the development of thrombus formation. Deep Vein Thrombosis occurs in situations where people are immobile for long periods of time, whether this is a result of ill health or travel on land or in the air. …


The Effects Of Combined Compression And Aging On The Properties Of Glassy Polycarbonate, Kyle W. Strabala Aug 2009

The Effects Of Combined Compression And Aging On The Properties Of Glassy Polycarbonate, Kyle W. Strabala

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Physical aging and plastic flow are known to cause changes in the properties of glassy polycarbonate (PC). Although the individual effects of physical aging and plastic flow have been studied, the combined mechanical and thermal effects have yet to be evaluated for PC at large plastic strains. This work is the first characterization of the combined effects in PC of large plastic flow followed by thermal (physical) aging. To conduct this study, samples were prepared with different extents of plastic compressive strain, up to approximately 50% engineering strain, followed by thermal aging up to 135 °C, with various …


Optimization Of Inp Apds For High-Speed Lightwave Systems, Daniel S.G. Ong, Jo Shien Ng, Majeed M. Hayat, John P.R. David Aug 2009

Optimization Of Inp Apds For High-Speed Lightwave Systems, Daniel S.G. Ong, Jo Shien Ng, Majeed M. Hayat, John P.R. David

Electrical and Computer Engineering Faculty Research and Publications

Calculations based on a rigorous analytical model are carried out to optimize the width of the indium phosphide avalanche region in high-speed direct-detection avalanche photodiode-based optical receivers. The model includes the effects of intersymbol interference (ISI), tunneling current, avalanche noise, and its correlation with the stochastic avalanche duration, as well as dead space. A minimum receiver sensitivity of -28 dBm is predicted at an optimal width of 0.18 mum and an optimal gain of approximately 13, for a 10 Gb/s communication system, assuming a Johnson noise level of 629 noise electrons per bit. The interplay among the factors controlling the …


Multilayer Image Inpainting Approach Based On Neural Networks, Quan Wang, Zhaoxia Wang, Che Sau Chang, Ting Yang Aug 2009

Multilayer Image Inpainting Approach Based On Neural Networks, Quan Wang, Zhaoxia Wang, Che Sau Chang, Ting Yang

Research Collection School Of Computing and Information Systems

This paper describes an image inpainting approach based on the self-organizing map for dividing an image into several layers, assigning each damaged pixel to one layer, and then restoring these damaged pixels by the information of their respective layer. These inpainted layers are then fused together to provide the final inpainting results. This approach takes advantage of the neural network's ability of imitating human's brain to separate objects of an image into different layers for inpainting. The approach is promising as clearly demonstrated by the results in this paper.


Setting Discrete Bid Levels Adaptively In Repeated Auctions, Jilian Zhang, Hoong Chuin Lau, Jialie Shen Aug 2009

Setting Discrete Bid Levels Adaptively In Repeated Auctions, Jilian Zhang, Hoong Chuin Lau, Jialie Shen

Research Collection School Of Computing and Information Systems

The success of an auction design often hinges on its ability to set parameters such as reserve price and bid levels that will maximize an objective function such as the auctioneer revenue. Works on designing adaptive auction mechanisms have emerged recently, and the challenge is in learning different auction parameters by observing the bidding in previous auctions. In this paper, we propose a non-parametric method for determining discrete bid levels dynamically so as to maximize the auctioneer revenue. First, we propose a non-parametric kernel method for estimating the probabilities of closing price with past auction data. Then a greedy strategy …


Development Of A High Performance Micropropulsion System For Cubesats, Christopher Lorian Biddy Aug 2009

Development Of A High Performance Micropropulsion System For Cubesats, Christopher Lorian Biddy

Master's Theses

Picosatellites are defined as satellites with a mass between 0.1 and 1kg (Miniaturized satellite). Picosatellites are typically designed to work together or function in formations (Miniaturized satellite). A specific type of Picosatellite known as CubeSats were introduced in 1999 and since then have increased in popularity so that there are now over 80 CubeSat programs around the world. CubeSats are defined as cubic units 10cm on each side and no more than 1kg in mass. CubeSats are required to conform to the CubeSat Standard created by California Polytechnic State University and Stanford University and be compatible with Cal Poly’s P-POD …


Performance Analysis And Life Prediction For Small Wind Turbine Blades: A Wood Laminate Case Study, Christopher James Nosti Aug 2009

Performance Analysis And Life Prediction For Small Wind Turbine Blades: A Wood Laminate Case Study, Christopher James Nosti

Master's Theses

A detailed study of the fatigue life of wooden wind turbine blades for a new 10 kilowatt system was undertaken. A numerical model of the blades was created using the technical software package MATLAB in order to estimate the maximum stress occurring within the blade in response to changes in wind velocities based on a wind profile approximating the location where these turbines are expected to operate. The material properties of the wooden laminate were measured using an Instron tensile test machine and were found to be in line with published values. In parallel with this effort, a three dimensional …


Efficient Embedded Speech Recognition For Very Large Vocabulary Mandarin Car-Navigation Systems, Yanmin Qian, Jia Liu, Michael T. Johnson Aug 2009

Efficient Embedded Speech Recognition For Very Large Vocabulary Mandarin Car-Navigation Systems, Yanmin Qian, Jia Liu, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

Automatic speech recognition (ASR) for a very large vocabulary of isolated words is a difficult task on a resource-limited embedded device. This paper presents a novel fast decoding algorithm for a Mandarin speech recognition system which can simultaneously process hundreds of thousands of items and maintain high recognition accuracy. The proposed algorithm constructs a semi-tree search network based on Mandarin pronunciation rules, to avoid duplicate syllable matching and save redundant memory. Based on a two-stage fixed-width beam-search baseline system, the algorithm employs a variable beam-width pruning strategy and a frame-synchronous word-level pruning strategy to significantly reduce recognition time. This algorithm …


Seismic Evaluation Of Clark County Critical Bridges Using Nonlinear Static Procedures, Ahmad Said Saad Aug 2009

Seismic Evaluation Of Clark County Critical Bridges Using Nonlinear Static Procedures, Ahmad Said Saad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridges are vital connective elements in community transportation systems. In the past, bridges have been severely damaged by earthquakes. However, with proper mitigation techniques, such as bridge retrofit, severe earthquake damage to bridges can be avoided. Since the 1970’s, design codes underwent major changes with regard to seismic analysis and design provisions of structures and bridges. Meanwhile, one third of the nation’s 600,000 inventoried highway bridges are considered as either structurally deficient or functionally obsolete.

This study is a part of the “Earthquakes in Southern Nevada” project. Earlier in this project, buildings and bridges in southern Nevada were studied in …


Digitally-Tunable Surface Acoustic Wave Resonator, Robert Russell Hay Aug 2009

Digitally-Tunable Surface Acoustic Wave Resonator, Robert Russell Hay

Boise State University Theses and Dissertations

Surface acoustic wave (SAW) technology has been utilized in numerous research and commercial devices since the practical implementation was enabled by the availability of suitable photolithographic techniques in the 1970s. With the traditional approach to implementing these devices the frequency response is established during manufacture. This dissertation proposes a different approach to implementing a SAW device. The SAW structure is added to the top of an integrated circuit so that the frequency response can be digitally controlled and the peak resonant frequency can be varied. The approach is based on implementing a phase-controlled interface between the SAW transducer fingers and …


Analytical, Computational And Experimental Studies Of Capillary Flow In Complex Geometries, Yongqing Peng Aug 2009

Analytical, Computational And Experimental Studies Of Capillary Flow In Complex Geometries, Yongqing Peng

Dissertations

The dynamic processes of capillary flow in complex geometries have been studied analytically, computationally and experimentally in this research. A general approach for modeling the capillary flow in arbitrary irregular geometries with straight axis of symmetry is proposed. Using this approach, the governing equation to describe the dynamic capillary rising motion in capillaries with nonuniform elliptical cross-section is first derived under the assumptions of parabolic distribution of the axial velocity and constant contact angle. The calculation results for the capillary flow in different tubes with irregular wall show that, in comparison with existing models that have been tested, the present …


Abstracting Gis Layers From Hyperspectral Imagery, Torsten E. Howard, Michael J. Mendenhall, Gilbert L. Peterson Aug 2009

Abstracting Gis Layers From Hyperspectral Imagery, Torsten E. Howard, Michael J. Mendenhall, Gilbert L. Peterson

Faculty Publications

The spectral-spatial relationship of materials in a hyperspectral image cube is exploited to partially automate the creation of Geographic Information System (GIS) layers. The topological neighborhood preservation property of the Self Organizing Map (SOM) is clustered into six (partially overlapping) neighborhoods that are mapped into the image domain to locate in-scene structures of similar material type. GIS layers are abstracted through spatial logical and morphological operations on the six image domain material maps and a novel road finding algorithm connects road segments under significant tree-occlusion resulting in a contiguous road network. It is assumed that specific knowledge of the scene …


Proton Irradiation Effects On Semiconductor Cdse/Zns Core/Shell Nanocrystals, Stephen Graham Charter Aug 2009

Proton Irradiation Effects On Semiconductor Cdse/Zns Core/Shell Nanocrystals, Stephen Graham Charter

Graduate Theses and Dissertations

The absorbance and photoluminescence measurement of semiconductor CdSe/ZnS core shell nanocrystals were reviewed and investigated after they were exposed to proton irradiation. The CdSe/ZnS core shell nanocrystals of 3.2nm and 4.4nm were commercially purchased and investigated. These nanocrystals were embedded in UV resin. Proton irradiation of energy 2MeV was applied at doses from 3 x 1013 protons cm-2 to 1.47 x 1015 protons cm-2 for both nanocrystal sizes. Absorbance measurements were conducted at 300K. Results from absorbance measurements showed slight broadening of the first exciton peak of both samples but was most noticeable in the 3.2nm nanocrystal sample. UV resin …


100 Ways You Can Use Google (Besides Searching), Marziah Karch Jul 2009

100 Ways You Can Use Google (Besides Searching), Marziah Karch

SIDLIT Conference Proceedings

Google has dozens of tools for educators and students. Learn how to make forms that feed into spreadsheets, blogs, social networks, websites, collaborative documents, videos, and more. During economic downturns it's more important than ever to make sure you and your students are utilizing free tools for collaborative learning and communication.


Preliminary Report On Integration Of Florida's Code Energy Efficiencies Using The 2009 Iecc As The Foundation Code, Florida Solar Energy Center, Philip W. Fairey Jul 2009

Preliminary Report On Integration Of Florida's Code Energy Efficiencies Using The 2009 Iecc As The Foundation Code, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

The Florida Building Commission is in the initial phase of it triennial revision of the Florida Building Code. The Florida Building Code has included specific energy provisions since its inception in 2001. Those provisions are the Florida Energy Code (FEC), which was initiated in 1979. In 2008, the Florida legislature enacted HB 7135, requiring the 2010 FEC to provide 20% energy savings compared with the 2007 FEC. HB 7135 also requires that the energy provisions of the Florida Building Code use the 2009 IECC as the foundation and that the IECC shall be modified to maintain the efficiencies of the …


Integration Of Multiple Data Types In 3-D Immersive Virtual Reality (Vr) Environments, George Demetrius Lecakes Jr. Jul 2009

Integration Of Multiple Data Types In 3-D Immersive Virtual Reality (Vr) Environments, George Demetrius Lecakes Jr.

Theses and Dissertations

Intelligent sensors have begun to play a key part in the monitoring and maintenance of complex infrastructures. Sensors have the capability not only to provide raw data, but also provide "information" by indicating the reliability of the measurements. The effect of this added information is a voluminous increase in the total data that is gathered. If an operator is required to perceive the state of a complex system, novel methods must be developed for sifting through enormous data sets. Virtual reality (VR) platforms are proposed as ideal candidates for performing this task-- a virtual world will allow the user to …


Modeling Of Subcontinuum Thermal Transport Across Semiconductor-Gas Interfaces, Dhruv Singh, Xiaohui Guo, Alina Alexeenko, Jayathi Y. Murthy, Timothy S. Fisher Jul 2009

Modeling Of Subcontinuum Thermal Transport Across Semiconductor-Gas Interfaces, Dhruv Singh, Xiaohui Guo, Alina Alexeenko, Jayathi Y. Murthy, Timothy S. Fisher

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

A physically rigorous computational algorithm is developed and applied to calculate subcontinuum thermal transport in structures containing semiconductor-gas interfaces. The solution is based on a finite volume discretization of the Boltzmann equation for gas molecules in the gas phase and phonons in the semiconductor. A partial equilibrium is assumed between gas molecules and phonons at the interface of the two media, and the degree of this equilibrium is determined by the accommodation coefficients of gas molecules and phonons on either side of the interface. Energy balance is imposed to obtain a value of the interface temperature. The classic problem of …


Twitter, Tumblr, Yammer, Huh? - How To Navigate Massive Information Streams And Have A Life, Marziah Karch Jul 2009

Twitter, Tumblr, Yammer, Huh? - How To Navigate Massive Information Streams And Have A Life, Marziah Karch

SIDLIT Conference Proceedings

Twitter has been getting a lot of attention lately, but it's not the only emerging application out there. In fact, by the time this presentation rolls around, there may already be something else making headlines. Learn why these new tools can help you as educators, lean how to use them, and learn how to navigate the tools without drowning in a sea of information and ending up with no life.


Property Price Data Would Stop Values Based On Sentiment, Lorcan Sirr Jul 2009

Property Price Data Would Stop Values Based On Sentiment, Lorcan Sirr

Media

No abstract provided.