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2012

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Articles 5791 - 5820 of 6303

Full-Text Articles in Engineering

Adaptive Dynamic Programming For High-Dimensional, Multicollinear State Spaces, Bancha Ariyajunya Jan 2012

Adaptive Dynamic Programming For High-Dimensional, Multicollinear State Spaces, Bancha Ariyajunya

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Dynamic programming (DP) is a mathematical programming method for optimizing a system changing over time and has been used to solve multi-stage optimization problems in manufacturing systems, environmental engineering, and many other fields. Exact solutions are only possible for small problems or under very limiting restrictions, but computationally practical approximate DP methods now exist. Most continuous-state problems require discretization of the state space. A design and analysis of computer experiments (DACE) approach for approximate DP uses experimental design and statistical modeling to approximate the value function in continuous-state problems. However, ideal experimental designs are orthogonal, and when the state variables …


Cnt Reinforced Epoxy Foamed And Electrospun Nano-Fiber Interlayer Systems For Manufacturing Lighter And Stronger Featherweight Composites, Vasileios M. Drakonakis Jan 2012

Cnt Reinforced Epoxy Foamed And Electrospun Nano-Fiber Interlayer Systems For Manufacturing Lighter And Stronger Featherweight Composites, Vasileios M. Drakonakis

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Multiple works have been performed in improving carbon fiber reinforced polymer (CFRP) composites especially in terms of strength so delamination, which is the major defect in laminated composites, is prevented. Nevertheless, there is not much focus on improving conventional CFRP systems in terms of weight especially when these are used in primary structures. This work questions whether lighter and at the same time stronger CFRP composites can be manufactured in order to replace conventional CFRP systems in major applications. Under this perspective, this study demonstrates that inducing controlled porosity may offer a systemic approach for manufacturing light weight carbon fiber …


Thrust Vector Control Of An Upper-Stage Rocket With Multiple Propellant Slosh Modes, Mahmut Reyhanoglu, Jaime Rubio Hervas Jan 2012

Thrust Vector Control Of An Upper-Stage Rocket With Multiple Propellant Slosh Modes, Mahmut Reyhanoglu, Jaime Rubio Hervas

Physical Sciences - Daytona Beach

“The thrust vector control problem for an upper-stage rocket with propellant slosh dynamics is considered. The control inputs are defined by the gimbal deflection angle of a main engine and a pitching moment about the center of mass of the spacecraft. The rocket acceleration due to the main engine thrust is assumed to be large enough so that surface tension forces do not significantly affect the propellant motion during main engine burns. A multi-mass-spring model of the sloshing fuel is introduced to represent the prominent sloshing modes. A nonlinear feedback controller is designed to control the translational velocity vector and …


An Investigation On Cocombustion Behaviors Of Hydrothermally Treated Municipal Solid Waste With Coal Using A Drop-Tube Reactor, Liang Lu, Yuqi Jin, Masato R. Nakamura, Marco J. Castaldi, Kunio Yoshikawa Jan 2012

An Investigation On Cocombustion Behaviors Of Hydrothermally Treated Municipal Solid Waste With Coal Using A Drop-Tube Reactor, Liang Lu, Yuqi Jin, Masato R. Nakamura, Marco J. Castaldi, Kunio Yoshikawa

Publications and Research

This work aims at demonstrating the feasibility of replacing Indonesian coal (INC) with hydrothermally treated municipal solid waste (MSWH) in cocombustion with high ash Indian coal (IC). The combustion efficiencies and emissions (CO, NO) of MSWH, INC and their blends with IC for a series of tests performed under a range of temperatures and air conditions were tested in a drop- tube reactor (DTR). The results showed the following. The combustion efficiency of IC was increased by blending both MSWH and INC and CO emission was reduced with increasing temperature. For NO emission, the blending of MSWH led to the …


Assessing The Therapeutic Effect Of 630 Nm Light-Emitting Diodes Irradiation On The Recovery Of Exercise-Induced Hand Muscle Fatigue With Surface Electromyogram, Dandan Yang, Xiaoying Wu, Wensheng Hou, Xiaolin Zheng, Jun Zheng, Yingtao Jiang Jan 2012

Assessing The Therapeutic Effect Of 630 Nm Light-Emitting Diodes Irradiation On The Recovery Of Exercise-Induced Hand Muscle Fatigue With Surface Electromyogram, Dandan Yang, Xiaoying Wu, Wensheng Hou, Xiaolin Zheng, Jun Zheng, Yingtao Jiang

Electrical & Computer Engineering Faculty Research

This paper aims to investigate the effect of light emitting diode therapy (LEDT) on exercise-induced hand muscle fatigue by measuring the surface electromyography (sEMG) of flexor digitorum superficialis. Ten healthy volunteers were randomly placed in the equal sized LEDT group and control group. All subjects performed a sustained fatiguing isometric contraction with the combination of four fingertips except thumb at 30% of maximal voluntary contraction (MVC) until exhaustion. The active LEDT or an identical passive rest therapy was then applied to flexor digitorum superficialis. Each subject was required to perform a re-fatigue task immediately after therapy which was the same …


Las Vegas Strip Odor Remediation, Francell R. Rodriguez, Daniel Hoskins, Guadalupe Gutierrez Jan 2012

Las Vegas Strip Odor Remediation, Francell R. Rodriguez, Daniel Hoskins, Guadalupe Gutierrez

Calvert Undergraduate Research Awards

The project described in our report looks at four alternatives to eliminate odor from the intersection of Las Vegas Blvd and Flamingo Rd: biofiltration, Granulated Activated Carbon (GAC) filtration, nitrate addition and the alternative of doing nothing. The odor is caused mainly by hydrogen sulfide, which escapes from the sewer system in this area. Each alternative was evaluated based on effectiveness, land usage, energy consumption, water and material usage, and cost. Cost was further broken down into initial costs and annual costs, and then a cash flow analysis was performed to evaluate the cost over a 30 year timeframe.

Nitrate …


Communication In Engineering: Developing A Targeted Course, Krysta Nicole Kirsch Jan 2012

Communication In Engineering: Developing A Targeted Course, Krysta Nicole Kirsch

Communication & Leadership Dissertations and Theses

In many technical undergraduate programs, specifically engineering, focus is placed on developing the technical abilities of students. Little emphasis is placed on communication, to include verbal, written, and presentation skills. In a dynamic corporate world, technical students can be put at a disadvantage if they are not taught the importance of being able to communicate with a variety of demographics in varying contexts. Companies are looking for engineering graduates who have strengths in both arenas. To address this issue, a semester-long communication course for engineering majors has been developed. The foundation is in current research on communication apprehension, the communication …


Compressed Air Foam Fire Grounds Evolution Tests, Justin A. Lapolla, Alexander L. Morano, Vincent P. Luchsinger Jan 2012

Compressed Air Foam Fire Grounds Evolution Tests, Justin A. Lapolla, Alexander L. Morano, Vincent P. Luchsinger

Mechanical Engineering

Compressed air foam firefighting technology has been purchased by a number of urban fire departments in the United States. These departments have curtailed their use of these systems until potential safety hazards associated with the use of compressed air foam systems in interior structure fires are evaluated. This project is part of a greater effort to evaluate the efficacy and practicality of compressed air foam systems for use in structural firefighting. This project focused on developing test apparatuses and test methods for measuring the following safety-related parameters: 1.) nozzle reaction force of a fire nozzle, 2.) the force required to …


Mandibular Bone Mechanics And Evaluation Of Temporomandibular Joint Devices, Shirishkumar Marutirao Ingawale Jan 2012

Mandibular Bone Mechanics And Evaluation Of Temporomandibular Joint Devices, Shirishkumar Marutirao Ingawale

Browse all Theses and Dissertations

Knowledge of the mandibular and temporomandibular joint (TMJ) biomechanics is of importance in various clinical scenarios as it helps better understanding of the structure and function necessary to diagnose, prevent, and treat temporomandibular disorder (TMD). The objectives of this dissertation research were to characterize biomechanical behavior of cadaveric human mandible, and to design and analyze patient-specific total TMJ prostheses. We performed a combined experimental-numerical study to validate the finite element (FE) models of 16 cadaveric human mandibles by comparing strain gauge measurements with FE-predicted surface strains. Analysis of experimental data showed that strains at the condylar locations were significantly different …


Measurement And Analysis Of Vehicle Vibration For Delivering Packages In Small‐Sized And Medium‐Sized Trucks And Automobiles, Vanee Chonhenchob, Sher Paul Singh, Jay Jagjit Singh, Joseph Stallings, Gary Grewal Jan 2012

Measurement And Analysis Of Vehicle Vibration For Delivering Packages In Small‐Sized And Medium‐Sized Trucks And Automobiles, Vanee Chonhenchob, Sher Paul Singh, Jay Jagjit Singh, Joseph Stallings, Gary Grewal

Industrial Technology and Packaging

In distribution, packaged products are subjected to the variation in vibration levels from transport vehicles that vary in frequency and acceleration while moving to their destinations. This vibration may negatively affect the product or packaging. This study measured and analysed vibration levels in vehicles commonly used to transport packages in the last leg of the package delivery service that is used by single‐parcel carriers. Using data recorders, we monitored vertical, lateral and longitudinal vibrations over 75 h of travel time in five different types of small and medium package delivery vehicles. The study presents these data as power density (PD) …


Computational Analysis Of Hybrid Norwood Circulation With Distal Aortic Arch Obstruction And Reverse Blalock-Taussig Shunt, Andres Ceballos, I. Ricardo Argueta-Morales, Eduardo Divo, Ruben Osorio, Christopher A. Caldarone, Alain J. Kassab, William M. Decampli Jan 2012

Computational Analysis Of Hybrid Norwood Circulation With Distal Aortic Arch Obstruction And Reverse Blalock-Taussig Shunt, Andres Ceballos, I. Ricardo Argueta-Morales, Eduardo Divo, Ruben Osorio, Christopher A. Caldarone, Alain J. Kassab, William M. Decampli

Mechanical Engineering - Daytona Beach

BACKGROUND: The hemodynamics characteristics of the hybrid Norwood (HN) procedure differ from those of the conventional Norwood and are not fully understood. We present a multi-scale model of HN circulation to understand local hemodynamics and effects of aortic arch stenosis and a reverse Blalock-Taussig shunt (RBTS) on coronary and carotid perfusion. METHODS: Four 3-dimensional models of four HN anatomic variants were developed, with and without 90% distal preductal arch stenosis and with and without a 4-mm RBTS. A lumped parameter model of the circulation was coupled to a local 3-dimensional computational fluid dynamics model. Outputs from the lumped parameter model …


Computational Fluid Dynamics In Congenital Heart Disease, William M. Decampli, I. Ricardo Argueta-Morales, Eduardo Divo, Alain J. Kassab Jan 2012

Computational Fluid Dynamics In Congenital Heart Disease, William M. Decampli, I. Ricardo Argueta-Morales, Eduardo Divo, Alain J. Kassab

Mechanical Engineering - Daytona Beach

Computational fluid dynamics has been applied to the design, refinement, and assessment of surgical procedures and medical devices. This tool calculates flow patterns and pressure changes within a virtual model of the cardiovascular system. In the field of paediatric cardiac surgery, computational fluid dynamics is being used to elucidate the optimal approach to staged reconstruction of specific defects and study the haemodynamics of the resulting anatomical configurations after reconstructive or palliative surgery. In this paper, we review the techniques and principal findings of computational fluid dynamics studies as applied to a few representative forms of congenital heart disease.


An Inverse Pod-Rbf Network Approach To Parameter Estimation In Mechanics, Craig A. Rogers, Alain Kassab, Eduardo Divo, Ziemowit Ostrowski, Ryszard Bialecki Jan 2012

An Inverse Pod-Rbf Network Approach To Parameter Estimation In Mechanics, Craig A. Rogers, Alain Kassab, Eduardo Divo, Ziemowit Ostrowski, Ryszard Bialecki

Mechanical Engineering - Daytona Beach

An inverse approach is formulated using proper orthogonal decomposition (POD) integrated with a trained radial basis function (RBF) network to estimate various physical parameters of a specimen with little prior knowledge of the system. To generate the truncated POD-RBF network utilized in the inverse problem, a series of direct solutions based on FEM, BEM or exact analytical solutions are used to generate a data set of temperatures or deformations within the system or body, each produced for a unique set of physical parameters. The data set is then transformed via POD to generate an orthonormal basis to accurately solve for …


The Effect Of Time-Delay Feedback Controller On An Electrically Actuated Resonator, S. Shao, K. M. Masri, Mohammad I. Younis Jan 2012

The Effect Of Time-Delay Feedback Controller On An Electrically Actuated Resonator, S. Shao, K. M. Masri, Mohammad I. Younis

Mechanical Engineering Faculty Scholarship

This paper presents a study of the effect of a time-delay feedback controller on the dynamics of a Microelectromechanical systems (MEMS) capacitor actuated by DC and AC voltages. It is shown that negative time-delay feedback control gain can lead to an unstable system, even if AC voltage is relatively small compared to DC voltage. Perturbation method is utilized to present analytically the nonlinear dynamic characteristics of the MEMS capacitor. Agreements among the results of a shooting technique, long-time integration, basin of attraction analysis with the perturbation method are achieved.


Dynamics Of A Close-Loop Controlled Mems Resonator, Abdulrahman Seleim, Shahrzad Towfighian, Emmanuel Delande, Eihab Abdel-Rahman, Glenn Heppler Jan 2012

Dynamics Of A Close-Loop Controlled Mems Resonator, Abdulrahman Seleim, Shahrzad Towfighian, Emmanuel Delande, Eihab Abdel-Rahman, Glenn Heppler

Mechanical Engineering Faculty Scholarship

The dynamics of a close-loop electrostatic MEMS resonator, proposed as a platform for ultra sensitive mass sensors, is investigated. The parameter space of the resonator actuation voltage is investigated to determine the optimal operating regions. Bifurcation diagrams of the resonator response are obtained at five different actuation voltage levels. The resonator exhibits bi-stability with two coexisting stable equilibrium points located inside a lower and an upper potential wells. Steady-state chaotic attractors develop inside each of the potential wells and around both wells. The optimal region in the parameter space for mass sensing purposes is determined. In that region, steady-state chaotic …


Are Posture Data From Simulated Tasks Representative Of Field Conditions? Case Study For Overhead Electric Utility Workers, Cristiane Shinohara Moriguichi, Leticia Carnaz, Luiz Carlos De Miranda Jr, Richard W. Marklin, Helenice Jane Cote Gil Coury Jan 2012

Are Posture Data From Simulated Tasks Representative Of Field Conditions? Case Study For Overhead Electric Utility Workers, Cristiane Shinohara Moriguichi, Leticia Carnaz, Luiz Carlos De Miranda Jr, Richard W. Marklin, Helenice Jane Cote Gil Coury

Mechanical Engineering Faculty Research and Publications

Many ergonomics studies are conducted in laboratory-simulated work environments to assess risks for the development of musculoskeletal disorders under more controlled conditions. However, the simulated conditions could be of questionable validity with respect to reproduction of field conditions involving risk factors. The objective of this study was to verify whether the postures recorded for neck extension/flexion and upper arm elevation of overhead electric utility workers in a simulated environment were similar to those recorded in a field environment. Of the three frequently performed tasks analysed, two presented similar exposure in both conditions. However, differences were identified for a more complex …


Commercial Construction Supply Chain Management Issues Involving Traveling Contractors, Fred Akers Jan 2012

Commercial Construction Supply Chain Management Issues Involving Traveling Contractors, Fred Akers

Masters Theses

Supply chain management (SCM) is an important aspect of running any business. To stay competitive in today's marketplace a supply chain management system must be in place to achieve success in this volatile global environment (Fewings, 2005).

This research differentiates the issues between executing a construction project close to home compared to away from home. Being away from home, there typically is no supplier relationship established. Furthermore, the research intends to document certain issues of the commercial construction industry that develop during the execution of a project. This will be based on the comparison of having or not having an …


Many-To-One Communication Protocol For Wireless Sensor Networks, Chansu Yu, Robert Fiske, Seungmin Park, Won-Tae Kim Jan 2012

Many-To-One Communication Protocol For Wireless Sensor Networks, Chansu Yu, Robert Fiske, Seungmin Park, Won-Tae Kim

Electrical and Computer Engineering Faculty Publications

This paper proposes a novel communication protocol, called Many-to-One Sensors-to-Sink (MOSS), tailored to wireless sensor networks (WSNs). It exploits the unique sensors-to-sink traffic pattern to realize low-overhead medium access and low- latency sensors-to-sink routing paths. In conventional schedule-based MAC protocols such as S-MAC, sensor nodes in the proximity of the event generate reports simultaneously, causing unreliable and unpredictable performance during a brief but critical period of time when an event of interest occurs. MOSS is based on time division multiple access (TDMA) that avoids energy waste due to collisions, idle listening and overhearing and avoids unreliable behavior mentioned above. A …


Optical Fluid-Based Photonic And Display Devices, Su Xu Jan 2012

Optical Fluid-Based Photonic And Display Devices, Su Xu

Electronic Theses and Dissertations

Conventional solid-state photonic devices exhibit an ultra-high optical performance and durability, but minimal adaptability. Recently, optical fluid-based photonic and display devices are emerging. By dynamically manipulating the optical interface formed by liquids, the optical output can be reconfigured or adaptively tuned in real time. Such devices exhibit some unique characteristics that are not achievable in conventional solid-state photonic devices. Therefore, they open a gateway for new applications, such as image and signal processing, optical communication, sensing, and lab-on-a-chip, etc. Different operation principles of optical fluidbased photonic devices have been proposed, for instance fluidic pressure, electrochemistry, thermal effect, environmentally adaptive hydrogel, …


Ecological Payback Time Of An Energy-Efficient Modular Building, Jeremy Faludi, Michael Lepech Jan 2012

Ecological Payback Time Of An Energy-Efficient Modular Building, Jeremy Faludi, Michael Lepech

Dartmouth Scholarship

Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient, prefabricated building. A life-cycle assessment was performed for a 5,000 ft2 commercial building designed by Project Frog and prefabricated in San Francisco, California, and compared to the impacts of annual energy consumption and continued status quo operation of a comparable average commercial building. Scenarios were run both with and without rooftop solar panels intended to make the prefabricated building net zero energy. The analysis considers the materials and mof the existing building, compared to continued annual energy use of …


Overview Of The 2010 Carbonaceous Aerosols And Radiative Effects Study (Cares), Rahul A. Zaveri, William J. Shaw, Daniel J. Cziczo, Beat Schmid, Richard Ferrare, M. Lizabeth Alexander, Raul Alvarez, W. Patrick Arnott, Dean B. Atkinson, Sunil Baidar, Robert M. Banta, James Barnard, Josef Beranek, Larry K. Berg, Fred Brechtel, W. Alan Brewer, John F. Cahill, Brian Cairns, Christopher D. Cappa, D. Chand, S. China, Jennifer M. Comstock, Manvendra K. Dubey, Robert C. Easter, M. H. Erickson, Jerome Fast, Cody Floerchinger, B. Flowers, Edward C. Fortner, Jeffrey S. Gaffney, Mary K. Gilles, Kyle Gorkowski, William Gustafson, Madhu Gyawali, J. Hair, R. M. Hardesty, Joseph Harworth, Scott C. Herndon, Naruki Hiranuma, Chris Hostetler, John M. Hubbe, John T. Jayne, H. Jeong, B. Tom Jobson, Evgueni Kassianov, Lawrence I. Kleinman, C. Kluzek, W. Berk Knighton, Katheryn R. Kolesar, Chongai Kuang, Alena Kubátová, Andrew O. Langford, Alexander Laskin, N. Laulainen, Richard D. Marchbanks, Claudio Mazzoleni, Fan Mei, Ryan C. Moffet, Dan Nelson, Michael Obland, Hilke Oetjen, Timothy B. Onasch, I. Ortega, Matteo Ottaviani, Mikhail Pekour, Kimberly A. Prather, James Gregory Radney, Raymond R. Rogers, Scott P. Sandberg, Arthur J. Sedlacek, Christoph J. Senff, Gunnar I. Senum, Ari Setyan, John E. Shilling, Manishkumar Shrivastava, C. Song, Stephen R. Springston, R. Subramanian, Kaitlyn Suski, Jason Tomlinson, Rainer M. Volkamer, H. W. Wallace, Jian Wang, A. M. Weickmann, Douglas R. Worsnop, Xiao-Ying Yu, Alla Zelenyuk, Qi Zhang Jan 2012

Overview Of The 2010 Carbonaceous Aerosols And Radiative Effects Study (Cares), Rahul A. Zaveri, William J. Shaw, Daniel J. Cziczo, Beat Schmid, Richard Ferrare, M. Lizabeth Alexander, Raul Alvarez, W. Patrick Arnott, Dean B. Atkinson, Sunil Baidar, Robert M. Banta, James Barnard, Josef Beranek, Larry K. Berg, Fred Brechtel, W. Alan Brewer, John F. Cahill, Brian Cairns, Christopher D. Cappa, D. Chand, S. China, Jennifer M. Comstock, Manvendra K. Dubey, Robert C. Easter, M. H. Erickson, Jerome Fast, Cody Floerchinger, B. Flowers, Edward C. Fortner, Jeffrey S. Gaffney, Mary K. Gilles, Kyle Gorkowski, William Gustafson, Madhu Gyawali, J. Hair, R. M. Hardesty, Joseph Harworth, Scott C. Herndon, Naruki Hiranuma, Chris Hostetler, John M. Hubbe, John T. Jayne, H. Jeong, B. Tom Jobson, Evgueni Kassianov, Lawrence I. Kleinman, C. Kluzek, W. Berk Knighton, Katheryn R. Kolesar, Chongai Kuang, Alena Kubátová, Andrew O. Langford, Alexander Laskin, N. Laulainen, Richard D. Marchbanks, Claudio Mazzoleni, Fan Mei, Ryan C. Moffet, Dan Nelson, Michael Obland, Hilke Oetjen, Timothy B. Onasch, I. Ortega, Matteo Ottaviani, Mikhail Pekour, Kimberly A. Prather, James Gregory Radney, Raymond R. Rogers, Scott P. Sandberg, Arthur J. Sedlacek, Christoph J. Senff, Gunnar I. Senum, Ari Setyan, John E. Shilling, Manishkumar Shrivastava, C. Song, Stephen R. Springston, R. Subramanian, Kaitlyn Suski, Jason Tomlinson, Rainer M. Volkamer, H. W. Wallace, Jian Wang, A. M. Weickmann, Douglas R. Worsnop, Xiao-Ying Yu, Alla Zelenyuk, Qi Zhang

Chemistry Faculty Publications and Presentations

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was …


Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho Jan 2012

Non-Reciprocal Wave Transmission In Integrated Waveguide Array Isolators, Tony Yatming Ho

Electronic Theses and Dissertations

Non-reciprocal wave transmission is a phenomenon witnessed in certain photonic devices when the wave propagation dynamics through the device along one direction differs greatly from the dynamics along the counter-propagating direction. Specifically, it refers to significant power transfer occurring in one direction, and greatly reduced power transfer in the opposite direction. The resulting effect is to isolate the directionality of wave propagation, allowing transmission to occur along one direction only. Given the popularity of photonic integrated circuits (PIC), in which all the optical components are fabricated on the same chip so that the entire optical system can be made more …


Infrared Tapered Slot Antennas Coupled To Tunnel Diodes, Louis A. Florence Jan 2012

Infrared Tapered Slot Antennas Coupled To Tunnel Diodes, Louis A. Florence

Electronic Theses and Dissertations

Tapered slot antennas (TSAs) have seen considerable application in the millimeter-wave portion of the spectrum. Desirable characteristics of TSAs include symmetric E- and H-plane antenna patterns, and broad non-resonant bandwidths. We investigate extension of TSA operation toward higher frequencies in the thermal infrared (IR), using a metal-oxide-metal diode as the detector. Several different infrared TSA design forms are fabricated using electronbeam lithography and specially developed thin-film processes. The angular antenna patterns of TSA-coupled diodes are measured at 10.6 micrometer wavelength in both E- and H-planes, and are compared to results of finite-element electromagnetic modeling using Ansoft HFSS. Parameter studies are …


High-Efficiency Blue Phase Liquid Crystal Displays, Yan Li Jan 2012

High-Efficiency Blue Phase Liquid Crystal Displays, Yan Li

Electronic Theses and Dissertations

Blue phase liquid crystals (BPLCs) have a delicate lattice structure existing between chiral nematic and isotropic phases, with a stable temperature range of about 2 K. But due to short coherent length, these self-assembled nano-structured BPLCs have a fast response time. In the past three decades, the application of BPLC has been rather limited because of its narrow temperature range. In 2002, Kikuchi et al. developed a polymer stabilization method to extend the blue-phase temperature range to more than 60 K. This opens a new gateway for display and photonic applications. In this dissertation, I investigate the material properties of …


Laser Filamentation Interaction With Materials For Spectroscopic Applications, Matthew Weidman Jan 2012

Laser Filamentation Interaction With Materials For Spectroscopic Applications, Matthew Weidman

Electronic Theses and Dissertations

Laser filamentation is a non-diffracting propagation regime consisting of an intense core that is surrounded by an energy reservoir. For laser ablation based spectroscopy techniques such as Laser Induced Breakdown Spectroscopy (LIBS), laser filamentation enables the remote delivery of high power density laser radiation at long distances. This work shows a quasiconstant filament-induced mass ablation along a 35 m propagation distance. The mass ablated is sufficient for the application of laser filamentation as a sampling tool for plasma based spectroscopy techniques. Within the scope of this study, single-shot ablation was compared with multi-shot ablation. The dependence of ablated mass on …


Urban Particulate Matter Activates Akt In Human Lung Cells, T. L. Watterson, B. Hamilton, Randy S. Martin, R. A. Coloumb Jr. Jan 2012

Urban Particulate Matter Activates Akt In Human Lung Cells, T. L. Watterson, B. Hamilton, Randy S. Martin, R. A. Coloumb Jr.

Civil and Environmental Engineering Faculty Publications

The normally picturesque Cache Valley in northern Utah is frequently reported to have the worst particulate (PM) air pollution in the United States. Numerous epidemiological studies conducted elsewhere have associated PM exposure to a variety of cardiovascular diseases and early mortality. We have previously shown that Cache Valley PM (CVPM) is pro-inflammatory, through a variety of mechanisms involving the release of inflammatory cytokines, unfolded protein response, ER stress, and C-reactive protein (CRP). This study was undertaken to determine whether Cache Valley PM (CVPM) would activate Akt, an upstream mechanism common to these events. Human lung (BEAS-2B) cells were treated with …


Geographical Assessment Of Microalgae Biofuels Potential Incorporating Resource Availability, Jason C. Quinn, Kimberly Catton, Sara Johnson, Thomas H. Bradley Jan 2012

Geographical Assessment Of Microalgae Biofuels Potential Incorporating Resource Availability, Jason C. Quinn, Kimberly Catton, Sara Johnson, Thomas H. Bradley

Mechanical and Aerospace Engineering Faculty Publications

Previous assessments of the economic feasibility and large-scale productivity of microalgae biofuels have not considered the impacts of land and carbon dioxide (CO2) availability on the scalability of microalgae-based biofuels production. To accurately assess the near-term productivity potential of large-scale microalgae biofuel in the US, a geographically realized growth model was used to simulate microalgae lipid yields based on meteorological data. The resulting lipid productivity potential of Nannochloropsis under large-scale cultivation is combined with land and CO2 resource availability illustrating current geographically feasible production sites and corresponding productivity in the US. Baseline results show that CO2 transport constraints will limit …


Spatially Localized Measurement Of Thermal Conductivity Using A Hybrid Photothermal Technique, Zilong Hua, Heng Ban, Marat Khafizov, Robert Schley, Rory Kennedy, David H. Hurley Jan 2012

Spatially Localized Measurement Of Thermal Conductivity Using A Hybrid Photothermal Technique, Zilong Hua, Heng Ban, Marat Khafizov, Robert Schley, Rory Kennedy, David H. Hurley

Mechanical and Aerospace Engineering Faculty Publications

A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k = (e2/D)1/2. To generalize this approach, sensitivity analysis is conducted for materials having a range of thermal conductivities. Application to nuclear fuel is consider by performing experimental validation using two materials (CaF2 and SiO2) having thermal properties representative of fresh and high burnup nuclear fuel. The measured conductivities compare favorably with literature values.


Parametric Study Of The Frequency-Domain Thermoreflectance Technique, C. Xing, C. Jensen, Z. Hua, Heng Ban, D. H. Hurley, M. Khafizov, J. R. Kennedy Jan 2012

Parametric Study Of The Frequency-Domain Thermoreflectance Technique, C. Xing, C. Jensen, Z. Hua, Heng Ban, D. H. Hurley, M. Khafizov, J. R. Kennedy

Mechanical and Aerospace Engineering Faculty Publications

Without requiring regression for parameter determination, one-dimensional (1D) analytical models are used by many research groups to extract the thermal properties in frequency-domain thermoreflectance measurements. Experimentally, this approach involves heating the sample with a pump laser and probing the temperature response with spatially coincident probe laser. Micron order lateral resolution can be obtained by tightly focusing the pump and probe lasers. However, small laser beam spot sizes necessarily bring into question the assumptions associated with 1D analytical models. In this study, we analyzed the applicability of 1D analytical models by comparing to 2D analytical and fully numerical models. Specifically, we …


Computer Aided Design Algorithmic Technique For Very Large Scale Integrated Circuit Design And Smart Home Embedded System Design, Xiaodao Chen Jan 2012

Computer Aided Design Algorithmic Technique For Very Large Scale Integrated Circuit Design And Smart Home Embedded System Design, Xiaodao Chen

Dissertations, Master's Theses and Master's Reports - Open

To tackle the challenges at circuit level and system level VLSI and embedded system design, this dissertation proposes various novel algorithms to explore the efficient solutions. At the circuit level, a new reliability-driven minimum cost Steiner routing and layer assignment scheme is proposed, and the first transceiver insertion algorithmic framework for the optical interconnect is proposed. At the system level, a reliability-driven task scheduling scheme for multiprocessor real-time embedded systems, which optimizes system energy consumption under stochastic fault occurrences, is proposed. The embedded system design is also widely used in the smart home area for improving health, wellbeing and quality …