Engineering Commons^™

Today’S Dot And The Quest For More Accountable Organizational Structures, Lenahan O'Connell, Juita-Elena (Wie) Yusuf, Merl Hackbart, Donald L. Hartman, Candice Wallace, Doug Kreis

Kentucky Transportation Center Research Report

This study investigates the impact of DOT organizational structures on effective transportation planning and performance. A review of the 50 state DOT authorizing statutes and DOT organizational charts found minimal differences in organizational structures among the states. However, 37 states have quasi-independent commissions (sometimes called boards, or councils.) A statistical analysis showed that the commission states have higher Government Performance Project (GPP) scores than the non-commission states. The analysis suggested that effective commissions avoid having members represent geographical regions and political parties and avoid giving the commission the power to select the director of the DOT. In addition the states …

Modeling Of Capacitor Impedance In Switching Converters, Jonathan W. Kimball, Philip T. Krein, Kevin R. Cahill

Electrical and Computer Engineering Faculty Research & Creative Works

Switched capacitor (SC) converters are gaining acceptance as alternatives to traditional, inductor-based switching power converters. Proper design of SC converters requires an understanding of all loss sources and their impacts on circuit operation. In the present work, an equivalent resistance method is developed for analysis, and equivalent resistance formulae are presented for various modes of operation. Quasiresonant converters are explored and compared to standard SC converters. Comparisons to inductor-based switching power converters are made. A number of capacitor technologies are evaluated and compared for applications to both SC converters and inductor-based converters. The resulting model can be used to accurately …

A Novel Method For Determination Of Dielectric Properties Of Materials Using A Combined Embedded Modulated Scattering And Near-Field Microwave Techniques-Part Ii: Dielectric Property Recalculation, R. Zoughi, Dana Hughes

Electrical and Computer Engineering Faculty Research & Creative Works

The use of combined embedded modulated scattering technique and near-field microwave nondestructive testing techniques is investigated as a novel method for evaluating the dielectric properties of a material. The forward formulation for determining the reflection coefficient at the aperture of a waveguide radiating into a dielectric half-space in which a PIN diode-loaded dipole (i.e., modulated scattering technique probe) is embedded was presented in Part I of this paper. Here, in Part II, the recalculation of the dielectric properties, using the results of the forward model, is presented along with some associated experimental results.

Socio-Economic Analysis Of Fatal Crash Trends (Final Report), Adam Kirk, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

This report describes the analysis of fatal crash patterns and explores the impact of socioeconomic factors and safety regulations on statewide crash rates. This analysis separated statewide crash rates between 2002 and 2004 into two samples, 1) those with crash rates 25 percent greater than the average national rate and 2) those with crash rates lower than this threshold. Safety regulations and socioeconomic factors were identified as having a significant effect on crash rates, with socioeconomic factors showing a higher potential to explain differences in crash rates between the two samples.

Seismic Lateral Response Of Piles In Liquefying Soil, D. S. Liyanapathirana, H. G. Poulos

Faculty of Engineering - Papers (Archive)

Soil liquefaction is one of the major factors affecting the behavior of piles founded in seismically active areas. Although methods are available for seismic analysis of pile foundations, in many of them, the supporting soil is assumed to be an elastic material. Here a numerical model is presented which takes into account the reduction of soil stiffness and strength due to pore pressure generation and subsequent soil liquefaction, in addition to the material nonlinearity. Results obtained from the new method are compared with centrifuge test data and show excellent agreement with the observed pile behavior during these tests. To investigate …

Human Error And General Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using Hfacs, Douglas Wiegmann, Troy Faaborg, Albert Boquet, Cristy Detwiler, Kali Holcomb, Scott Shappell

Publications

The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research performed at both the University of Illinois and the Civil Aerospace Medical Institute has successfully shown that HFACS can be reliably used to analyze the underlying human causes of both commercial and general aviation (GA) accidents. These analyses have helped identify general trends in the types of human factors issues and aircrew errors that have contributed to civil aviation accidents. The next step was to identify the exact nature of the human errors identified. …

Effect Of Gender On Lower Extremity Kinematics During Rapid Direction Changes: An Integrated Analysis Of Three Sports Movements, S. G. Mclean, K. B. Walker, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Anterior cruciate ligament (ACL) injury is a common sports injury, particularly in females. Gender differences in knee kinematics have been observed for specific movements, but there is limited information on how these findings relate to other joints and other movements. Here we present an integrated analysis of hip, knee and ankle kinematics across three movements linked to non-contact ACL injury. It was hypothesised that there are gender differences in lower extremity kinematics, which are consistent across sports movements. Ten female and ten male NCAA basketball players had three-dimensional hip, knee and ankle kinematics quantified during the stance phase of sidestep, …

Lattice Quantum Algorithm For The Schrodinger Wave Equation In 2+1 Dimensions With A Demonstration By Modeling Soliton Instabilities, Jeffrey Yepez, George Vahala, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

A lattice-based quantum algorithm is presented to model the non-linear Schrödinger-like equations in 2 + 1 dimensions. In this lattice-based model, using only 2 qubits per node, a sequence of unitary collide (qubit-qubit interaction) and stream (qubit translation) operators locally evolve a discrete field of probability amplitudes that in the long-wavelength limit accurately approximates a non-relativistic scalar wave function. The collision operator locally entangles pairs of qubits followed by a streaming operator that spreads the entanglement throughout the two dimensional lattice. The quantum algorithmic scheme employs a non-linear potential that is proportional to the moduli square of the wave function. …

Fiscal Year 2005 Fhwa-536 Report For The Kentucky Transportation Cabinet, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Federal Highway Administration (FHWA) requires state transportation agencies to submit a biennial report on local highway finances. The purpose of these reports is to provide FHWA with the data it needs to capture the financing of highway activities at the local level. Based on this information, it can identify trends in revenue, expenditures, investments, and program development, and in turn make decisions about future investments. The report, FHWA-536, asks agencies to report on four areas of local highway finance: 1) disposition of highway-user revenues; 2) revenues used for roads and streets identified by source and funding type; 3) road …

Ferroelectric Switch For Spin Injection, Mikhail Ye. Zhuravlev, Sitaram Jaswal, Evgeny Y. Tsymbal, Renat F. Sabirianov

Materials Research Science and Engineering Center: Faculty Publications

A method for the switching of the spin polarization of the electric current injected into a semiconductor is proposed, based on injecting spins from a diluted magnetic semiconductor through a ferroelectric tunnel barrier. We show that the reversal of the electric polarization of the ferroelectric results in a sizable change in the spin polarization of the injected current, thereby providing a two-state electrical control of this spintronic device. We also predict a possibility of switching of tunneling magnetoresistance in magnetic tunnel junctions with a ferroelectric barrier and coexistence of tunneling magnetoresistance and giant electroresistance effects in these multiferroic tunnel junctions.

Act/Sger: Atomic Layer Deposition Of Nitrides On Nano-Particles For Enhanced Energy Conversion To Combat Terrorism, William J. Desisto

University of Maine Office of Research Administration: Grant Reports

William J. DeSisto, University of Maine, will apply atomic layer deposition reactions to passivate nanoparticles. These coated nanoparticles will be used in next-generation, high energy density, compact energy storage devices. Initial experiments will focus on coating nano-sized lithium-ion battery anodes with titanium nitride. Miniaturized batteries using these anodes will be fabricated and evaluated by industrial collaborators at Yardley/Lithion Technical Products.

This award is supported jointly by the NSF Directorate for Mathematical and Physical Sciences and the Intelligence Community. The Approaches to Combat Terrorism Program supports new concepts in basic research and workforce development with the potential to contribute to national …

Roadmap Query For Sensor Network Assisted Navigation In Dynamic Environments, Sangeeta Bhattacharya, Nuzhet Atay, Gazihan Alankus, Chenyang Lu, O. Burchan Bayazit, Gruia-Catalin Roman

All Computer Science and Engineering Research

Autonomous mobile entity navigation through dynamic and unknown environments is an essential part of many mission critical applications like search and rescue and fire fighting. The dynamism of the environment necessitates the mobile entity to constantly maintain a high degree of awareness of the changing environment. This criteria makes it difficult to achieve good navigation performance by using just on-board sensors and existing navigation methods and motivates the use of wireless sensor networks (WSNs) to aid navigation. In this paper, we present a novel approach that integrates a roadmap based navigation algorithm with a novel network query protocol called Roadmap …

Group Scheduling In Selinux To Mitigate Cpu-Focused Denial Of Service Attacks, Armando Migliaccio, Terry Tidwell, Christopher Gill, Tejasvi Aswathanarayana, Douglas Niehaus

All Computer Science and Engineering Research

Popular security techniques such as public-private key encryption, firewalls, and role-based access control offer significant protec-tion of system data, but offer only limited protection of the computations using that data from significant interference due to accident or adversarial attack. However, in an increasing number of modern systems, ensuring the reliable execution of system activities is every bit as important as ensuring data security. This paper makes three contributions to the state of the art in protection of the execution of system activities from accidental or adversarial interference. First, we consider the motivating problem of CPU-focused denial of service attacks, and …

Recovery Of The Grain Boundary Character Distribution Through Oblique Double-Sectioning, Brent L. Adams, David T. Fullwood, E. R. Homer

Faculty Publications

This work was supported primarily by the MRSEC program of the National Science Foundation under DMR-0079996. A method for the retrieval of the complete grain boundary character distribution by oblique double-sectioning is proposed. The method, which is similar to the recovery of the orientation distribution from sets of incomplete pole-figures, is efficient and provides many advantages as compared to calibrated serial sectioning. As compared to standard stereological approaches, the new methodology retains the advantage of direct measurement of the grain boundary inclination parameters. Solutions to the fundamental equation of oblique double-sectioning are provided in the Fourier space, and some specifics …

Electronic Efficiency In Nanostructured Thermionic And Thermoelectric Devices, Mark F. O'Dwyer, R. A. Lewis, C. Zhang, T. E. Humphrey

Faculty of Engineering - Papers (Archive)

Advances in solid-state device design now allow the spectrum of transmitted electrons in thermionic and thermoelectric devices to be engineered in ways that were not previously possible. Here we show that the shape of the electron energy spectrum in these devices has a significant impact on their performance. We distinguish between traditional thermionic devices where electron momentum is filtered in the direction of transport only and a second type, in which the electron filtering occurs according to total electron momentum. Such “total momentum filtered” thermionic devices could potentially be implemented in, for example, quantum dot superlattices. It is shown that …

Negative Spin Polarization And Large Tunneling Magnetoresistance In Epitaxial Co|Srtio3|Co Magnetic Tunnel Junctions, Julian P. Velev, Kirill D. Belashchenko, Derek A. Stewart, Mark Van Schilfgaarde, Sitaram Jaswal, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

We perform an ab initio study of spin-polarized tunneling in epitaxial Co|SrTiO₃|Co magnetic tunnel junctions with bcc Co(001) electrodes. We predict a large tunneling magnetoresistance in these junctions, originating from a mismatch in the majority- and minority-spin bands both in bulk bcc Co and at the Co|SrTiO₃ interface. The intricate complex band structure of SrTiO₃ enables efficient tunneling of the minority d electrons which causes the spin polarization of the Co|SrTiO₃ interface to be negative in agreement with experimental data. Our results indicate that epitaxial Co|SrTiO₃|Co magnetic tunnel junctions with bcc Co(001) electrodes …

Highly Efficient Fluorescence Detection In Picoliter Volume Liquid-Core Waveguides, Aaron R. Hawkins, John P. Barber, Dongliang Yin

Faculty Publications

We report loss improvement and fluorescence detection in integrated antiresonant reflecting optical waveguides with liquid cores. The minimum waveguide loss is reduced to 0.33/cm by compensating for thickness variations in the fabrication process. We demonstrate fluorescence detection from as few as 490 molecules in a 57 pl core using these optimized waveguides. We measure angular fluorescence collection factors as high as 15% per facet in good agreement with theory. This demonstrates the potential of integrated hollow-core waveguides as optical sensors for single-molecule spectroscopy.

Effects Of Collective Excitations On The Quantum Well Intersubband Absorption, X. W. Mi, J. C. Cao, C. Zhang, F. B. Meng

Faculty of Engineering - Papers (Archive)

The dependence of the intersubband absorption spectra on the Coulomb interaction and quantum well (QW) width is studied. Rather than following the Fermi–Dirac distribution, we have solved the intersubband equations of motion to determine the subband population self-consistently. We have gone beyond the linear absorption theory to show the effect of various many-body interactions on the absorption spectra. It is found that the redistribution of electrons in excited states reduces the absorption. Our results indicate that the line shape and peak position are determined by the interplay of different collective excitations, such as the Fermi edge singularity and the intersubband …

Long Term Monitoring Of Trichloroethylene Degradation Indicator Parameters Using Sensors, Ravi Krishna Prasanth Gudavalli

FIU Electronic Theses and Dissertations

Past operations at Savannah River Site (SRS) have resulted in significant amount of groundwater contamination with trichloroethylene. Natural attenuation of chlorinated solvents via reductive dechlorination is one of the most important processes occurring at SRS, which requires monitoring. Many traditional monitoring techniques require manual sampling and analysis at an onsite or offsite laboratory, which is costly and time consuming. Therefore the need for a system, which can accurately and cost-effectively conduct real-time analysis using automated sensors, is important. There are several characteristics of groundwater like pH, ORP, conductivity and chloride that may be monitored to assess the TCE degradation. To …

Effect Of Blood Flow Patterns On Localized Platelet Adhesion Under Physiologic Flow Conditions Using Two-Dimensional And Three-Dimensional Stent Models - An Experimental And Computational Approach, Nandini Duraiswamy

FIU Electronic Theses and Dissertations

This dissertation presents dynamic flow experiments with fluorescently labeled platelets to allow for spatial observation of wall attachrent in inter-strut spacings, to investigate their relationship to flow patterns. Human blood with fluorescently labeled platelets was circulated through an in vitro system that produced physiologic pulsatile flow in (1) a parallel plate flow chamber that contained two-dimensional (2D) stents that feature completely recirculating flow, partially recirculating flow, and completely reattached flow, and (2) a three-dimensional (3D) cylindrical tube that contained stents of various geometric designs.

Flow detachment and reattachment points exhibited very low platelet deposition. Platelet deposition was very low in …

Using Ultrasonic Atomization To Produce An Aerosol Of Micron-Scale Particles, Thomas D. Donnelly, J. Hogan '03, A. Mugler '04, M. Schubmehl '02, N. Schommer '04, Andrew J. Bernoff, S. Dasnurkar, T. Ditmire

All HMC Faculty Publications and Research

A device that uses ultrasonic atomization of a liquid to produce an aerosol of micron-scale droplets is described. This device represents a new approach to producing targets relevant to laser-driven fusion studies, and to rare studies of nonlinear optics in which wavelength-scale targets are irradiated. The device has also made possible tests of fluid dynamics models in a novel phase space. The distribution of droplet sizes produced by the device and the threshold power required for droplet production are shown to follow scaling laws predicted by fluid dynamics.

Manure Use Planning Tools For Nebraska, Charles S. Wortmann, Charles A. Shapiro, Richard K. Koelsch, Richard Deloughery

Department of Biological Systems Engineering: Conference Presentations and White Papers

Three computer programs have been developed to facilitate manure use planning. The Nebraska Manure Value Calculator was developed in Excel to ease the calculation of manure value (www.cnmp.unl.edu) for a specific field giving value to needed nutrients and other expected benefits, and with the option of giving value to manure nutrients used in the more distant future. Nebraska MMPAMUP and MMP-CNMP Document Generators are planning tools for animal feeding operations that work with the Purdue University Manure Management Planner (MMP). Microsoft Word documents are generated which contain some boilerplate text that can be edited, popup lists in Word AutoText to …

Microbial Source Tracking: Tools For Refining Total Maximum Daily Load Assessments (2005), Stormwater Academy

BMP Trains Research and Publications

For over 100 years, indicator bacteria of fecal origin have been used to assess water quality and alert managers to increased risk of the presence of human pathogens. While these indicator organisms, including total coliforms and fecal coliforms, have helped protect public health for decades, they are now being utilized as surrogates for pathogens in total maximum daily load (TMDL) programs that are mandated by the US Environmental Protection Agency. The goal of TMDL assessment, which is carried out by the Florida Department of Environmental Protection in Florida, is ultimately to identify the sources of contaminant loading to Florida waters …

Are We Addressing The Cause Of Nutrient Problems?, Richard K. Koelsch

Department of Biological Systems Engineering: Conference Presentations and White Papers

Content:

Manure P vs. Crop Land P Use

One-Way Flow of Nutrients Is Underlying Cause

Future NMP Checklist?

Should an NMP Measure Environmental Performance?

Whole Farm Nutrient Balance

Whole Farm N Balance

Phosphorus Inputs to Livestock Systems

Should An NMP Estimate Ammonia Emissions?

Daily Ammonia Emissions from Livestock (36 km grid)

Ammonia Emissions Regulatory Thresholds

Ammonia Emissions – Swine Finishing Operations

Macromolecules In Graz, Austria, December 3, 2004, Otto Vogl, Volker Ribitsch

Emeritus Faculty Author Gallery

No abstract provided.

Distribution Pattern Variability Of Granular Vrt Applicators, John P. Fulton, Scott A. Shearer, Stephen F. Higgins, Dennis Wayne Hancock, Timothy S. Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

Granular applicators equipped with variable-rate technology (VRT) have gained popularity in recent years as a result of increased interest in variable-rate application. The purpose of this investigation was to characterize distribution patterns at varying rates for different granular applicators. Uniform-rate (UR) tests were conducted to assess the accuracy of variable-rate application from four granular applicators: two spinner-disc spreaders (A and B), and two pneumatic applicators (C and D). Pattern results indicated a consistent triangular pattern for spinner spreader B and consistent patterns for the pneumatic applicators (C and D). However, applicator D produced pattern variations at the center and right …

Bond Strength And Transfer Length Of Pre-Tensioned Bridge Girders Cast With Self-Consolidating Concrete, Amgad F. Morgan Girgis, Christopher Y. Tuan

Civil Engineering Faculty Publications

Self-consolidating concrete (SCC) is becoming increasingly popular in the precast/prestressed concrete industry in the United States. However, there have been concerns regarding the bond strength, transfer length, and development length of prestressing strands and mild steel reinforcement with SCC. Further, there are no design guidelines for using SCC. In this study, a literature survey on the bond strength of SCC was conducted. Moustafa pullout tests were performed to determine the bond strength of 0.6 in. (15.2 mm) pretensioning strands with sec. The transfer lengths of three pretensioned concrete bridge girders were measured using Demec points. Pullout tests were also performed …

Evaluation Of Cost Effective Sensor Combinations For A Vehicle Precrash Detection System, John Carlin, Charles Birdsong, Peter Schuster, William Thompson, Daniel Kawano

Mechanical Engineering

The future of vehicle safety will benefit greatly from precrash detection -the ability of a motor vehicle to predict the occurrence of an accident before it occurs. There are many different sensor technologies currently available for pre-crash detection. However no single sensor technology has demonstrated enough information gathering capability within the cost constraints of vehicle manufacturers to be used as a stand alone device. A proposed solution consists of combining information from multiple sensors in an intelligent computer algorithm to determine accurate precrash information. In this paper, a list of sensors currently available on motor vehicles and those that show …

Heat Generation In Municipal Solid Waste Landfills, Nazli Yesiller, James Hanson, Wei-Lien Liu

Civil and Environmental Engineering

This study was conducted to investigate thermal aspects of municipal solid waste landfills as a function of operational conditions and climatic region. Spatial and temporal distributions of waste temperatures were determined at four landfills located in North America (Michigan, New Mexico, Alaska, and British Columbia). Temperatures of wastes at shallow depths (extending to 6 to 8 m depth) and near the edges of a cell (within approximately 20 m) conformed to seasonal temperature variations, whereas steady elevated temperatures (23 to 57°C) with respect to air and ground temperatures were reached at depth and at central locations. Waste temperatures decreased from …

Role Of Higher-"Mode" Pushover Analyses In Seismic Analysis Of Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The role of higher-“mode” pushover analyses in seismic analysis of buildings is examined in this paper. It is demonstrated that the higher-“mode” pushover curves reveal plastic hinge mechanisms that are not detected by the first-“mode” or other FEMA-356 force distributions, but these purely local mechanisms are not likely to develop during realistic ground motions in an otherwise regular building without a soft and/or weak story. Furthermore, the conditions necessary for “reversal” of a higher-“mode” pushover curve are examined. It is shown that “reversal” in a higher-“mode” pushover curve occurs after formation of a mechanism if the resultant force above the …