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2014

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Articles 4531 - 4560 of 7242

Full-Text Articles in Engineering

Log-Periodic Dipole Array Antenna As Chipless Rfid Tag, S. Gupta, Gui Jun Li, R. C. Roberts, Li (Lijun) Jun Jiang Feb 2014

Log-Periodic Dipole Array Antenna As Chipless Rfid Tag, S. Gupta, Gui Jun Li, R. C. Roberts, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A passive chipless radio-frequency identification (RFID) tag based on a log-periodic (LP) dipole array is proposed, where the tailorable bandrejection property of the LP aperture is utilised to realise a large number of codes. The proposed tag principle is successfully validated by measurements, where the absence and presence of the band-rejection is shown to carry the bit information. Its fabrication simplicity is also demonstrated by its implementation on a flexible substrate. Finally, two different tag formation schemes, based on a specific set of resonance suppressions, are discussed in detail. © 2014 The Institution of Engineering and Technology.

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High-Resolution Mri For 3d Biomechanical Modeling: Signal Optimization Through Rf Coil Design And Mr Relaxometry, James A. Badal Feb 2014

High-Resolution Mri For 3d Biomechanical Modeling: Signal Optimization Through Rf Coil Design And Mr Relaxometry, James A. Badal

Theses and Dissertations

Computed Tomography (CT) is often used for building 3D biomechanical models of human anatomy. This method exposes the subject to a significant x-ray dose and provides limited soft-tissue contrast. Magnetic Resonance Imaging (MRI) is a potential alternative to CT for this application, as MRI offers significantly better soft-tissue contrast and does not expose the subject to ionizing radiation. However, MRI requires long scan times to achieve 3D images at sufficient resolution, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). These long scan times can make subject motion a problem. This thesis describes my work to reduce scan time while achieving sufficient …

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Analytical System For Planning Of Infrastructure Rehabilitation (Aspire), Purdue Ect Team Feb 2014

Analytical System For Planning Of Infrastructure Rehabilitation (Aspire), Purdue Ect Team

ECT Fact Sheets Archive

ASPIRE stands for Analytical System for Planning of Infrastructure REhabilitation, a decision support system that can be used for all kinds of infrastructure facilities. It is based on a rehabilitation modeling theory developed by Professor Makarand Hastak at Purdue University.

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A Systematic Study Of The Optical And Electrical Properties Of Ge1-YSnY And Ge1-X-YSiXSnY Semiconductor Alloys, Thomas R. Harris Feb 2014

A Systematic Study Of The Optical And Electrical Properties Of Ge1-YSnY And Ge1-X-YSiXSnY Semiconductor Alloys, Thomas R. Harris

Theses and Dissertations

In order to fully utilize newly developed Ge1-ySny and Ge1-x-ySixSny materials for new novel optoelectronic devices, the optical and electrical properties of these alloys were investigated using photoluminescence (PL) and Hall-effect measurements. Direct bandgap PL emission was observed from almost all the samples, making them very promising candidates for Si-based light emitting devices. T-dependent PL studies also indicate that the indirect-to-direct bandgap transition of Ge1-ySny alloys might take place at a much lower Sn content than the theory predicts. T-dependent Hall-effect measurements showed both degenerate parallel conducting layers as …

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Interplay Between Chain Stiffness And Excluded Volume Of Semiflexible Polymers Confined In Nanochannels, Abhiram Muralidhar, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman Feb 2014

Interplay Between Chain Stiffness And Excluded Volume Of Semiflexible Polymers Confined In Nanochannels, Abhiram Muralidhar, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman

Faculty Publications

The properties of channel-confined semiflexible polymers are determined by a complicated interplay of chain stiffness and excluded volume effects. Using Pruned-Enriched Rosenbluth Method (PERM) simulations, we study the equilibrium properties of channel-confined polymers by systematically controlling chain stiffness and excluded volume. Our calculations of chain extension and confinement free energy for freely jointed chains with and without excluded volume show excellent agreement with theoretical predictions. For ideal wormlike chains, the extension is seen to crossover from Odijk behavior in strong confinement to zero-stretching, bulk-like behavior in weak confinement. In contrast, for self-avoiding wormlike chains, we always observe that the linear …

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Developing Rubrics That Assess Specific Abet Student Outcomes, Byron G. Garry Feb 2014

Developing Rubrics That Assess Specific Abet Student Outcomes, Byron G. Garry

ASEE Best Practice Series Presentations

No abstract provided.

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Cama Newsletter - February, 2014, Civil Aviation Medical Association Feb 2014

Cama Newsletter - February, 2014, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

An eleven page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

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Tunneling Into The Mott Insulator Sr2Iro4, John A. Nichols, Noah Bray-Ali, Armin Ansary, Gang Cao, Kwok-Wai Ng Feb 2014

Tunneling Into The Mott Insulator Sr2Iro4, John A. Nichols, Noah Bray-Ali, Armin Ansary, Gang Cao, Kwok-Wai Ng

Center for Advanced Materials Faculty Publications

We studied the single-layered iridate Sr2IrO4 with a scanning tunneling microscope. The finite low temperature conductance enables the electronic structure of this antiferromagnetic Mott insulator to be measured by tunneling spectroscopy. We imaged the topography of freshly cleaved surfaces and measured differential tunneling conductance at cryogenic temperatures. We found the Mott gap in the tunneling density of states to be 2Δ=615 meV. Within the Mott gap, additional shoulders are observed which are interpreted as inelastic loss features due to magnons.

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Analyst B: Analysis Of The Utexas1 Passive Linear Surface Wave Dataset, Robb E.S. Moss Feb 2014

Analyst B: Analysis Of The Utexas1 Passive Linear Surface Wave Dataset, Robb E.S. Moss

Civil and Environmental Engineering

A linear array consisting of 24 1 Hz geophones at 10 m spacing was used to measure the passive surface waves at the UTexas1 site. This paper describes analysis of this dataset using three different methods: ESPAC (extended spatial autocorrelation), f-k (frequency-wavenumber), and ReMi (refraction microtremor). Dispersion curves were developed using each method and the median trends as well as the uncertainty about the medians are compared. The dispersion curves were then individually inverted to estimate shear wave velocity profiles. The inversion results are compared, and a bounded best-estimate shear wave velocity profile is presented. For the site conditions, specific …

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Laboratory Study Of The Effect Of Electromagnetic Waves On Airflow During Air Sparging, Atena Najafi, Vahab Bolvardi, Arvin Farid, Jim Browning, Elisa Barney Smith Feb 2014

Laboratory Study Of The Effect Of Electromagnetic Waves On Airflow During Air Sparging, Atena Najafi, Vahab Bolvardi, Arvin Farid, Jim Browning, Elisa Barney Smith

Civil Engineering Faculty Publications and Presentations

Air sparging is a technique that uses the injection of a gas (e.g., air, oxygen) into the subsurface to remediate saturated soils and groundwater contaminated with volatile organic compounds (VOCs). Contaminant-removal efficiency and air-sparging performance are highly dependent on the pattern and type of airflow. Airflow, however, suffers from air channel formation (i.e., preferential paths for airflow), limiting remediation to smaller contaminated zones. This paper presents the results of experimental work investigating the possibility of controlling and improving airflow patterns through a saturated glass-bead medium using electromagnetic (EM) waves to enhance air sparging. The test setup consists of a resonant …

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Electromagnetically Induced Transport In Water For Geoenvironmental Applications, Arvin Farid, Atena Najafi, Mahsa Azad, Jim Browning, Elisa Barney Smith Feb 2014

Electromagnetically Induced Transport In Water For Geoenvironmental Applications, Arvin Farid, Atena Najafi, Mahsa Azad, Jim Browning, Elisa Barney Smith

Civil Engineering Faculty Publications and Presentations

Air sparging is a popular soil remediation technique that enables the removal of contaminants through diffusing air into soil. The removal process is, however, slow. The goal of this work is to study the effect of electromagnetic (EM) waves —with minimal heat generation— on transport mechanisms such as diffusion, in order to improve airflow or contaminant transport in order to expedite the cleanup process using air sparging or similar technologies. This effect is studied through an experimental setup that examines the diffusion of a nonreactive dye in water under EM waves at a range of frequencies (50-200 MHz). The electric …

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Study Of Mechanisms Governing Electromagnetic Alteration Of Hydraulic Conductivity Of Soils, Atena Najafi, Sahba Azad, Arvin Farid, Jim Browning, Elisa Barney Smith Feb 2014

Study Of Mechanisms Governing Electromagnetic Alteration Of Hydraulic Conductivity Of Soils, Atena Najafi, Sahba Azad, Arvin Farid, Jim Browning, Elisa Barney Smith

Civil Engineering Faculty Publications and Presentations

Hydraulic conductivity is a measure of the rate at which water flows through porous media. Because of the dipole properties of water molecules, electric field can affect hydraulic conductivity. In this study, the effect of radio-frequency (RF) waves on hydraulic conductivity is investigated. This is important both for the geophysical measurement of hydraulic conductivity as well as remediation using electromagnetic waves. Bentonite clay and sandy samples are tested in rigid-wall, cylindrical permeameters and stimulated using a CPVC-cased monopole antenna vertically centered in the permeameters. The permeameters are encased within RF cavities constructed of aluminum mesh in order to prevent interference …

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Energy And Peak Power Reduction From Air Misting Products Applied To Commercial Condensing Units In Hot And Humid Climates, Florida Solar Energy Center, Charles Withers, Jr. Feb 2014

Energy And Peak Power Reduction From Air Misting Products Applied To Commercial Condensing Units In Hot And Humid Climates, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

A proprietary research project was conducted to evaluate the potential annual and peak energy reduction resulting from the addition of a water misting system applied to supermarket condenser coils in the Florida Power and Light service territory. Tests were performed to evaluate the performance of a mist system under various outdoor conditions over an eight-month period in a hot and humid climate zone. The project measured an average of 2.8% percentage energy savings and average 3.2% utility peak demand reduction. The report discusses why hot and humid climates can expect much lower savings compared to hot and arid climates. One …

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Data Link For Palamede Spacecraft Based On The Orbcomm Constellation As Space Infrastructure, Franco Bernelli-Zazzera Feb 2014

Data Link For Palamede Spacecraft Based On The Orbcomm Constellation As Space Infrastructure, Franco Bernelli-Zazzera

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Franco Bernelli-Zazzera on "Data link for Palamede spacecraft based on the Orbcomm constellation as space infrastructure" from February 21, 2014.

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Preparation Of Radiation-Grafted Powders For Use As Anion Exchange Ionomers In Alkaline Polymer Electrolyte Fuel Cells, Simon D. Poynton, Robert C. T. Slade, Travis J. Omasta, William E. Mustain, Ricardo Escudero-Cid, Pilar Ocón, John R. Varcoe Feb 2014

Preparation Of Radiation-Grafted Powders For Use As Anion Exchange Ionomers In Alkaline Polymer Electrolyte Fuel Cells, Simon D. Poynton, Robert C. T. Slade, Travis J. Omasta, William E. Mustain, Ricardo Escudero-Cid, Pilar Ocón, John R. Varcoe

Faculty Publications

A novel alkaline exchange ionomer (AEI) was prepared from the radiation-grafting of vinylbenzyl chloride (VBC) onto poly(ethylene-co-tetrafluoroethylene) [ETFE] powders with powder particle sizes of less than 100 μm diameter. Quaternisation of the VBC grafted ETFE powders with trimethylamine resulted in AEIs that were chemically the same as the ETFE-based radiation-grafted alkaline anion exchange membranes (AAEM) that had been previously developed for use in low temperature alkaline polymer electrolyte fuel cells (APEFC). The integration of the AEI powders into the catalyst layers (CL) of both electrodes resulted in a H2/O2 fuel cell peak power density of 240 mW cm−2 …

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Virgin River Multi-Objective Optimization: Maximizing Endangered Fish Habitat And Minimizing Costs, L. Basdekas, L. A. Bastidas, T. B. Hardy, Arthur J. Caplan, Mac Mckee Feb 2014

Virgin River Multi-Objective Optimization: Maximizing Endangered Fish Habitat And Minimizing Costs, L. Basdekas, L. A. Bastidas, T. B. Hardy, Arthur J. Caplan, Mac Mckee

Civil and Environmental Engineering Faculty Publications

This paper discusses a comparative analysis of hypothetical operational scenarios by the use of dynamic temperature and fish habitat modelling in a multi-objective framework in the Virgin River Basin, Utah. Results were compared on the basis of quantified fish habitat, operational costs, and hydropower revenue. The modelling framework, the Virgin River Operation Optimization Model, is considered as a basin-level planning model. The optimization objectives were to minimize net river system operational cost of the Washington County Water Conservation District and maximize endangered fish habitat. Considerations included infrastructure alternatives to increase flow and cold water discharges as well as demand reductions. …

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Student Mentoring In Research: Laser-Activated Drug Delivery To Cancer Cells, William G. Pitt Feb 2014

Student Mentoring In Research: Laser-Activated Drug Delivery To Cancer Cells, William G. Pitt

Journal of Undergraduate Research

Summary of Scope of Proposal This proposal was submitted in October of 2011 to organize and fund a mentoring group in the Pitt lab in Chemical Engineering. Marjan Javadi, then a PhD candidate in Chemical Engineering, and 5 uldergraduate students participated in this research group. The purpose was 2-­‐fold, both scientific and pedagogical. On the scientific side, Marjan was working on her PhD research to develop a novel drug delivery system called an eLiposome that encapsulated a drug along with a nanoemulsion that turns from liquid to gas upon exposure to ultrasound. The ultrasound can be non-­‐invasively (no surgery or …

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The Santa Clara,2014-02-20, Santa Clara University Feb 2014

The Santa Clara,2014-02-20, Santa Clara University

The Santa Clara

No abstract provided.

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Galileo, The European Global Navigation Satellite System:Status And Challenges, Marco Lisi Feb 2014

Galileo, The European Global Navigation Satellite System:Status And Challenges, Marco Lisi

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Marco Lisi on "Galileo, the European Global Navigation Satellite System:Status and Challenges" from February 20, 2014.

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Infrastructure For Planetary Science, Carle M. Pieters Feb 2014

Infrastructure For Planetary Science, Carle M. Pieters

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Carle M. Pieters on "Infrastructure for Planetary Science" from February 20, 2014.

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Current Developments In Space Infrastructure: Space Horizons 2014, Mason Peck Feb 2014

Current Developments In Space Infrastructure: Space Horizons 2014, Mason Peck

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Mason Peck on "Current Developments in Space Infrastructure: Space Horizons 2014" from February 20, 2014.

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Condition Assessment Of Concrete Bridge Decks: Sampling And Testing Of Decommissioned Bridges On Interstate 15 In Utah, W. Spencer Guthrie, Brian A. Mazzeo Feb 2014

Condition Assessment Of Concrete Bridge Decks: Sampling And Testing Of Decommissioned Bridges On Interstate 15 In Utah, W. Spencer Guthrie, Brian A. Mazzeo

Journal of Undergraduate Research

The objectives of this research were to obtain samples of four decommissioned concrete bridge decks that were replaced as part of the Interstate 15 (I-15) CORE project in Utah County and evaluate their condition using both non-destructive and destructive testing techniques. Because the decks were not returned to trafficking, extensive destructive testing could be performed. The testing was important for providing information about long-term deterioration mechanisms that occur in Utah bridge decks. Furthermore, because each of the sampled decks had been surfaced with an asphalt membrane-overlay system, testing the decks provided useful information about the efficacy of this rehabilitation approach …

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Mechanical Properties Of Components Fabricated With Open-Source 3-D Printers Under Realistic Environmental Conditions, B. M. Tymrak, M Kreiger, Joshua M. Pearce Feb 2014

Mechanical Properties Of Components Fabricated With Open-Source 3-D Printers Under Realistic Environmental Conditions, B. M. Tymrak, M Kreiger, Joshua M. Pearce

Department of Materials Science and Engineering Publications

he recent development of the RepRap, an open-source self-replicating rapid prototyper, has made 3-D polymer-based printers readily available to the public at low costs ( < $500). The resultant uptake of 3-D printing technology enables for the first time mass-scale distributed digital manufacturing. RepRap variants currently fabricate objects primarily from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA), which have melting temperatures low enough to use in melt extrusion outside of a dedicated facility, while high enough for prints to retain their shape at average use temperatures. In order for RepRap printed parts to be useful for engineering applications the mechanical properties of printed parts must be known. This study quantifies the basic tensile strength and elastic modulus of printed components using realistic environmental conditions for standard users of a selection of open-source 3-D printers. The results find average tensile strengths of 28.5 MPa for ABS and 56.6 MPa for PLA with average elastic moduli of 1807 MPa for ABS and 3368 MPa for PLA. It is clear from these results that parts printed from tuned, low-cost, open-source RepRap 3-D printers can be considered as mechanically functional in tensile applications as those from commercial vendors.

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Integrated Composite Reinforcement And Passive Damping Of Plywood Panels, Keith Steurer, Dr. Fernando Fonseca Feb 2014

Integrated Composite Reinforcement And Passive Damping Of Plywood Panels, Keith Steurer, Dr. Fernando Fonseca

Journal of Undergraduate Research

Composite reinforced plywood can be used in lightweight structures as well as high performance sporting equipment such as skis, skateboards and snowboards. Composite skins are adhered to the wood core to increase the stiffness of the plywood with very little addition in weight. The possibility exists to use a viscoelastic damping layer as the adhesive to increase adhesion strength between the composite skins and the plywood and create passive constrained layer damping in the composite reinforced plywood. This research investigated the damping performance of composite reinforced plywood using a viscoelastic adhesive.

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Quasars And Pulsars And Masers (Oh, My!), Michael Hecht Feb 2014

Quasars And Pulsars And Masers (Oh, My!), Michael Hecht

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Michael Hecht on "Quasars and Pulsars and Masers (Oh, my!)" from February 19, 2014.

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Pocketqubes: Access To Space Infrastructure For Small Organizations, Robert J. Twiggs Feb 2014

Pocketqubes: Access To Space Infrastructure For Small Organizations, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "PocketQubes: Access to space infrastructure for small organizations" from February 19, 2014.

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Pocketqubes: Access To Space Infrastructure For Small Organizations, Robert J. Twiggs Feb 2014

Pocketqubes: Access To Space Infrastructure For Small Organizations, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "PocketQubes: Access to space infrastructure for small organizations" from February 19, 2014.

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Development Of A Method Of Obtaining Fluid Temperature Measurements Using A Laser, Scott L. Thomson, Dr. Dan Maynes Feb 2014

Development Of A Method Of Obtaining Fluid Temperature Measurements Using A Laser, Scott L. Thomson, Dr. Dan Maynes

Journal of Undergraduate Research

Developing a method of measuring fluid temperature using a laser-based system was the goal of this research project. The following paragraphs summarize the research procedure, results, and plans for future development.

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Development Of A One-Piece, Aramid-Polyurethane Bumper System For Automobiles, Brent Zollinger, Dr. Christopher Rotz Feb 2014

Development Of A One-Piece, Aramid-Polyurethane Bumper System For Automobiles, Brent Zollinger, Dr. Christopher Rotz

Journal of Undergraduate Research

The automobile bumper system—consisting primarily of a decorative fascia, structural cross-beam, and energy absorber—is an ideal candidate for redesign using advanced technology. This report examines a concept that integrates the three main components of the bumper system into one by using high-performance materials. A one-piece, aramid-polyurethane composite bumper system that can be manufactured using the SRIM process offers possible weight reductions, cost reductions, and styling versatility, while maintaining manufacturability.

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Isotruss™ -Reinforced Concrete Beams, Justin Marshall, David Jensen, Fernando Fonseca Feb 2014

Isotruss™ -Reinforced Concrete Beams, Justin Marshall, David Jensen, Fernando Fonseca

Journal of Undergraduate Research

When a reinforced concrete beam is loaded it tends to sag or deflect. Because of this deflection, the bottom fibers of the beam are in tension while the top is compressed. Reinforcement (rebar) is placed in beams to resist tensile forces which concrete cannot support. Rebar can have adverse effects under certain conditions. If the concrete cracks, the steel will rust and expand causing increased cracking and strength loss. Other potential problems stem from steel’s density, magnetic properties and conductance. Currently, much research is being done in the area of composite reinforcement to solve these problems. Recent thesis research done …

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