Engineering Commons^™

Guidelines For Attachments To Bridge Rails And Median Barriers, Eric A. Keller, Dean L. Sicking, Ronald K. Faller, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

Highway agencies are often presented with the need to add attachments of various configurations to the top or backside of crashworthy traffic barriers. Although, the National Cooperative Highway Research Program (NCHRP) Report No. 350 offers guidance for the safety performance evaluation of traffic barriers, it offers no guidance toward the evaluation of attachments on or near these barriers. The objective of the research project was to collect crash test data relating to bridge rails and median barriers, to collect information about common attachments to traffic barriers, and to evaluate this information for the purpose of developing guidelines for the design …

Development Of A Low-Profile Bridge Rail For Test Level 2 Applications, Karla A. Polivka, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, James C. Holloway

Mid-America Transportation Center: Final Reports and Technical Briefs

A low-profile bridge rail was developed for installations where pedestrians and/or site restrictions prevent the use of conventional bridge rails with transitions. The bridge rail design was constructed using a 22.86-m long reinforced concrete parapet. The entire system measured 508-mm high by 356-mm and 279-mm wide at the top and bottom surfaces, respectively.

The research study included one full-scale vehicle crash test, using a 3⁄4-ton pickup truck. The full- scale test, impacting at a speed of 70.0 km/hr and an angle of 27.1 degrees, was conducted and reported in accordance with the requirements specified in National Cooperative Highway Research Program …

Bridge Rails And Transitions For Pedestrian Protection, Nicholas R. Hiser, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

It is desirable to protect pedestrians on bridges from motor vehicles. However, transition problems arise at the ends of bridges where the bridge rail, bridge rail end treatment, and pedestrian walkway compete for the limited available space. The objective of this study was to identify the most common scenarios in which the protection of pedestrians on bridges is desirable, and then to develop bridge rail and bridge rail end treatment configurations to accommodate those situations. The objective was achieved by performing a field investigation, a survey of state transportation agencies, and a literature review. Recommendations for the placement and general …

Bistable Memory Effect In Chromium Oxide Junctions, Andrei Sokolov, C.-S. Yang, E. Ovtchenkov, L. Yuan, Sy-Hwang Liou, Bernard Doudin

Materials Research Science and Engineering Center: Faculty Publications

Magnetotransport properties of granular CrO₂ /Cr₂O₃ films made of CrO₂ crystals covered by 1- 2 nm native insulating Cr₂O₃ are presented. Electrical properties of a limited number of grains measured in series and parallel (10 to 15 grains) reveal intergrain tunneling characteristics. At lowest temperatures, a well pronounced zero bias anomaly indicates that impurities in the junctions block the electronic flow.

Hysteresis in the IV curves are observed at intermediate temperatures on zero-field cooled samples. Changing the polarity of a short excitation pulse (100ns) of amplitude smaller than 1 V triggers a …

Substrate Dependent Bonding Of Chemisorbed 1,1’-Biphenyl-4,4’-Dimethanethiol, A. N. Caruso, R. Rajesekaran, Jody G. Redepenning, Yaroslav B. Losovyj, Peter A. Dowben

Materials Research Science and Engineering Center: Faculty Publications

We compare the adsorption of 1,1’-biphenyl-4,4’-dimethanethiol (BPDMT) on gold and cobalt surfaces. The molecular orbitals, identified from combined photoemission and inverse photoemission studies, exhibit shifts in binding energies with different deposition methods and substrates. These shifts indicate that this potential molecular dielectric exhibits stronger bonding to cobalt surfaces than gold surfaces.

Quantifying The Effects Of Small-Scale Heterogeneities On Flow And Transport In Undisturbed Cores From The Hanford Formation, M. N. Pace, M. A. Mayes, P. M. Jardine, T. L. Mehlhorn, John M. Zachara, B.N. Bjornstad

United States Department of Energy: Publications

Accelerated migration of contaminants in the vadose zone has been observed beneath tank farms at the U.S. Department of Energy’s Hanford Reservation, Richland, WA. This paper focuses on quantifying hydrologic processes that control the fate and transport of contaminants in the unsaturated sediments beneath the Hanford tank farms. The experimental approach involved the use of field relevant, long-term unsaturated nonreactive transport experiments in undisturbed sediments from the Hanford Formation. Undisturbed sediment cores were collected from a laminated fine-grained sand unit within the Hanford Formation in both the vertical direction (flow cross bedding) and the horizontal direction (flow bedding parallel). Laboratory-scale …

2003 Joint Government And Industry Pipeline R&D Forum Report

United States Department of Transportation: Publications

The U.S. Department of Transportation’s Office of Pipeline Safety (OPS) in conjunction with the energy pipeline industry’s collaborative R&D program administered jointly by Pipeline Research Council International, Inc (PRCI) and the Gas Technology Institute (GTI) hosted the Joint Government and Industry Pipeline R&D Forum. The Forum brought together over 130 representatives from State, Federal and foreign government offices along with domestic and foreign natural gas and hazardous liquid pipeline operators. The Forum’s goals included identifying key challenges facing industry and government, sharing information on current research efforts, and identifying research that can help to meet the challenges.

The Forum was …

Pipeline Safety Systematic Process Needed To Evaluate Outcomes Of Research And Development Program

United States Department of Transportation: Publications

OPS distributes its R&D budget among four main areas. For example, in fiscal year 2003, the office plans to allocate its $8.7 million budget as follows:

• 46 percent ($4.0 million) to developing new technologies to prevent damage to pipelines and prevent leaks;

• 21 percent ($1.9 million) to improving technologies for operating, controlling, and monitoring the condition of pipelines;

• 19 percent ($1.7 million) to improved pipeline materials, such as materials that are resistant to damage and defects; and

• 14 percent ($1.2 million) to efforts to improve data on the location and safety performance of pipelines.

On the …

Deformation Of A Peridynamic Bar, S. A. Silling, M. Zimmermann, R. Abeyaratne

United States Department of Energy: Publications

The deformation of an infinite bar subjected to a self-equilibrated load distribution is investigated using the peridynamic formulation of elasticity theory. The peridynamic theory differs from the classical theory and other nonlocal theories in that it does not involve spatial derivatives of the displacement field. The bar problem is formulated as a linear Fredholm integral equation and solved using Fourier transform methods. The solution is shown to exhibit, in general, features that are not found in the classical result. Among these are decaying oscillations in the displacement field and progressively weakening discontinuities that propagate outside of the loading region. These …

Heterogeneous Electron-Transfer Kinetics With Synchrotron 57fe Mossbauer Spectroscopy, J. E. Amonette, Ravi K. Kukkadapu, E. E. Alp, W. Sturhahn, T. S. Toellner

United States Department of Energy: Publications

In the first known kinetic application of the technique, synchrotron ⁵⁷Fe-Mössbauer spectroscopy was used to follow the rate of heterogeneous electron transfer between aqueous reagents and a solid phase containing Fe. The solid, a synthetic ⁵⁷Fe-enriched Fe (III)-bearing pyroaurite-like phase having terephthalate (TA) in the interlayer [Mg₃Fe (OH)₈(TA)_0.5 • 2H₂O], was reduced by Na₂S₂O₄ and then reoxidized by K₂Cr₂O₇ by means of a novel flow-through cell. Synchrotron Mössbauer spectra were collected in the time domain at 30-s intervals. Integration of the …

Secondary Mineralization Pathways Induced By Dissimilatory Iron Reduction Of Ferrihydrite Under Advective Flow, Colleen M. Hansel, Shawn G. Benner, Jim Neiss, Alice Dohnalkova, Ravi K. Kukkadapu, Scott Fendorf

United States Department of Energy: Publications

Iron (hydr)oxides not only serve as potent sorbents and repositories for nutrients and contaminants but also provide a terminal electron acceptor for microbial respiration. The microbial reduction of Fe (hydr)oxides and the subsequent secondary solid-phase transformations will, therefore, have a profound influence on the biogeochemical cycling of Fe as well as associated metals. Here we elucidate the pathways and mechanisms of secondary mineralization during dissimilatory iron reduction by a common iron-reducing bacterium, Shewanella putrefaciens (strain CN32), of 2-line ferrihydrite under advective flow conditions. Secondary mineralization of ferrihydrite occurs via a coupled, biotic-abiotic pathway primarily resulting in the production of magnetite …

Inhibition Of Bacterial U(Vi) Reduction By Calcium, Scott Brooks, James K. Fredrickson, Sue Carroll, David Kennedy, John M. Zachara, Andrew Plymale, Shelly Kelley, Kenneth Kemner, Scott Fendorf

United States Department of Energy: Publications

The rapid kinetics of bacterial U(VI) reduction and low solubility of uraninite (UO_2,cr) make this process an attractive option for removing uranium from groundwater. Nevertheless, conditions that may promote or inhibit U(VI) reduction are not well-defined. Recent descriptions of Ca-UO₂- CO₃ complexes indicate that these species may dominate the aqueous speciation of U(VI) in many environments. We monitored the bacterial reduction of U(VI) in bicarbonate buffered solution in the presence and absence of Ca. XAFS measurements confirmed the presence of a Ca- U(VI)-CO₃ complex in the initial solutions containing calcium. Calcium, at millimolar concentrations …

Novel Small Molecule Inhibitors Of Botulinum Neurotoxin A Metalloprotease Activity, James C. Burnett, James J. Schmidt, Robert G. Stafford, Rekha G. Panchal, Tam L. Nguyen, Ann R. Hermone, Jonathan L. Vennerstrom, Connor F. Mcgrath, Douglas J. Lane, Edward A. Sausville, Daniel W. Zaharevitz, Rick Gussio, Sina Bavari

United States Army: Publications

Botulinum neurotoxins (BoNTs) are among the most lethal biological substances to have been weaponized and are listed as biodefense category A agents. Currently, no small molecule (non-peptidic) therapeutics exist to counter this threat; hence, identifying and developing compounds that inhibit BoNTs is a high priority. In the present study, a high-throughput assay was used to identify small molecules that inhibit the metalloprotease activity of BoNT serotype A light chain (BoNT/A LC). All inhibitors were further verified using a HPLC-based assay. Conformational analyses of these compounds, in conjunction with molecular docking studies, were used to predict structural features that contribute to …

Protracted Protection To Plasmodium Berghei Malaria Is Linked To Functionally And Phenotypically Heterogeneous Liver Memory Cd8+ T Cells1, Dmitri Berenzon, Robert J. Schwenk, Lisa Letellier, Mimi Guebre-Xabier, Jackie Williams, Urszula Krzych

United States Army: Publications

We previously demonstrated that protection induced by radiation-attenuated (y) Plasmodium berghei sporozoites is linked to MHC class I-restricted CD⁸⁺ T cells specific for exoerythrocytic-stage Ags, and that activated intrahepatic memory CD⁸⁺ T cells are associated with protracted protection. In this study, we further investigated intrahepatic memory CD⁸⁺ T cells to elucidate mechanisms required for their maintenance. Using phenotypic markers indicative of activation (CD44, CD45RB), migration (CD62L), and IFN-y production, we identified two subsets of intrahepatic memory CD⁸⁺ T cells: the CD44^highCD45RB^lowCD62L^lowCD122^low phenotype, representing the dominant effector …

Graduate School Of Computer And Information Sciences Graduate Catalog 2003-2004, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Ultrafine Nife2o4 Powder Fabricated From Reverse Microemulsion Process, Jiye Fang, Narayan Shama, Le Duc Tung, Eun Young Shin, Charles J. O'Connor, Kevin L. Stokes, Gabriel Caruntu, John B. Wiley, Leonard Spinu, Jinke Tang

Physics Faculty Publications

NiFe2O4 ultrafine powder with high crystallinity has been prepared through a reverse microemulsion route. The composition in starting solution was optimized, and the resulting NiFe2O4 was formed at temperature of around 550–600 °C, which is much lower than that observed from the solid-state reaction. Magnetic investigation indicates that samples are soft-magnetic materials with low coercivity and with the saturation magnetization close to the bulk value of Ni ferrite.

Experimental Studies Assessing The Repeatability Of A Functional Modeling Derivation Method, Mark A. Kurfman, Michael E. Stock, Robert B. Stone, Jagan Rajan, Kristin L. Wood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents the results of research attempts to substantiate repeatability and uniqueness claims of a functional model derivation method following a hypothesis generation and testing procedure outlined in design research literature. Three experiments are constructed and carried out with a participant pool that possesses a range of engineering design skill levels. the experiments test the utility of a functional model derivation method to produce repeatable functional models for a given product among different designers. in addition to this, uniqueness of the functional models produced by the participants is examined. Results indicate the method enhances repeatability and leads designers toward …

Mapping Function To Failure Mode During Component Development, Irem Y. Tumer, Robert B. Stone

Mechanical and Aerospace Engineering Faculty Research & Creative Works

When designing aerospace systems, it is essential to provide crucial failure information for failure prevention. Failure modes and effect types of analyses and prior engineering knowledge and experience are commonly used to determine the potential modes of failures a product might encounter during its lifetime. When new products are being considered and designed, this knowledge and information is expanded upon to help designers extrapolate based on their similarity with existing products and the potential design tradeoffs. in this work, we aim to enhance this process by providing design-aid tools which derive similarities between functionality and failure modes. Specifically, this paper …

Guidelines For The Development Of Computer-Based Instruction Modules For Science And Engineering, Jessica R. Lux, Barry D. Davidson

Mechanical and Aerospace Engineering - All Scholarship

The design and development of a prototype computer-based instruction (CBI) module is described. The module covers introductory structural analysis techniques and demonstrates the practicality of CBI for undergraduate engineering education. The module’s generic learning objectives are used to develop a set of guiding principles for CBI development. Choice of authoring software and the module architecture are presented, followed by the details of the user interface, logic, and screen layout. The module design and software development process outlined here are easily extended to computer-based tutorials that present problem solving methods for engineering, mathematics, and the natural sciences.

A Framework For Aggregating Network Performance In Distributed Brokering Systems, Gurhan Gunduz, Shrideep Pallickara, Geoffrey C. Fox

Electrical Engineering and Computer Science - All Scholarship

The Internet is presently being used to support increasingly complex interaction models as a result of more and more applications, services and frameworks becoming network-centric. Efficient utilization of network and networked resources is of paramount importance. Network performance gathering is a precursor to any scheme that seeks to provide adaptive routing capabilities for interactions. In this paper we present a network performance aggregation framework that is extensible and appropriate for distributed messaging systems that span multiple realms, disparate communication protocols and support different applications.

Impedance Probe To Measure Local Gas Volume Fraction And Bubble Velocity In A Bubbly Liquid, Ashok S. Sangani, R. Zenit, Donald L. Koch

Biomedical and Chemical Engineering - All Scholarship

We have developed a dual impedance-based probe that can simultaneously measure the bubble velocity and the gas volume fraction in length scales comparable to the bubble diameter. The accurate determination of the profiles is very important for comparisons with existing theories that describe the rheological behavior of bubbly liquids. The gas volume fraction is determined by the residence time of bubble within the measuring volume of the probe. We have found that the details of the bubble-probe interactions must be taken into account to obtain an accurate measure of the gas volume fraction at a point. We are able to …

Missile Longitudinal Autopilot Design Using A New Suboptimal Nonlinear Control Method, Ming Xin, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A missile longitudinal autopilot is designed using a new nonlinear control synthesis technique called the θ-D approximation. The particular θ-D methodology used is referred to as the θ-D H2 design. The technique can achieve suboptimal closed-form solutions to a class of nonlinear optimal control problems in the sense that it solves the Hamilton-Jacobi-Bellman equation approximately by adding perturbations to the cost function. An interesting feature of this method is that the expansion terms in the expression for suboptimal control are nothing but solutions to the state-dependent Riccati equations associated with this class of problems. The θ-D H2 design has the …

Proper Orthogonal Decomposition Based Modeling And Experimental Implementation Of A Neurocontroller For A Heat Diffusion System, Prashant Prabhat, S. N. Balakrishnan, Dwight C. Look, Radhakant Padhi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Experimental implementation of a dual neural network based optimal controller for a heat diffusion system is presented. Using the technique of proper orthogonal decomposition (POD), a set of problem-oriented basis functions are designed taking the experimental data as snap shot solutions. Using these basis functions in Galerkin projection, a reduced-order analogous lumped parameter model of the distributed parameter system is developed. This model is then used in an analogous lumped parameter problem. A dual neural network structure called adaptive critics is used to obtain optimal neurocontrollers for this system. In this structure, one set of neural networks captures the relationship …

Test 1824: Challenger Mt845 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Protocols For Disease Classification From Mass Spectrometry Data, Michael Wagner, Dayanand Naik, Alex Pothen

Mathematics & Statistics Faculty Publications

We report our results in classifying protein matrix-assisted laser desorption/ionizationtime of flight mass spectra obtained from serum samples into diseased and healthy groups. We discuss in detail five of the steps in preprocessing the mass spectral data for biomarker discovery, as well as our criterion for choosing a small set of peaks for classifying the samples. Cross-validation studies with four selected proteins yielded misclassification rates in the 10-15% range for all the classification methods. Three of these proteins or protein fragments are down-regulated and one up-regulated in lung cancer, the disease under consideration in this data set. When cross-validation studies …

Smart Bridges With Fiber-Optic Sensors, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

This article describes an approach to bridge improvements that uses smart structures, introduces key technologies for health monitoring systems based on fiber optics and gives an overview of two instrumented bridges. A sensing system in one application monitors general performance and health of the structure, while the system in a second application interrogates the behavior of a major structural repair.

Spectrum Visualization And Measurement Of Power Parameters Of Microwave Wideband Noise, Marina Koledintseva, Alexander A. Kitaytsev, V. A. Konkin, V. Radchenko

Electrical and Computer Engineering Faculty Research & Creative Works

A method for an adequate visualization of a microwave intense noise envelope in a wide frequency range (several octaves), measuring of its power parameters, and detection of a narrowband signal with unknown frequency and power against the noise background is presented. This method is based on an application of a nonheterodyne principle of microwave frequency (and power) conversion using a gyromagnetic converter, which operates in two regimes in turn: the resonance detection and the cross-multiplication. A block-scheme and an operation of a two-channel measuring device combining the mentioned functions are discussed.

Control Of Cascaded Multi-Level Inverters, Keith Corzine, Fang Zheng Peng, J. Wang, M. W. Wielebski

Electrical and Computer Engineering Faculty Research & Creative Works

A new type of multi-level inverter is introduced which is created by cascading two three-phase three-level inverters using the load connection. This new inverter can operate as a nine-level inverter and naturally splits the power conversion into a higher voltage lower-frequency inverter and a lower-voltage higher frequency inverter. This type of system presents particular advantages to naval ship propulsion systems which rely on high power quality, survivable drives. New control methods are described involving both joint and separate control of the individual three-level inverters. Simulation results demonstrate the effectiveness of both controls. A laboratory set-up at the Naval Surface Warfare …

Simulation Models With Correct Statistical Properties For Rayleigh Fading Channels, Y. Rosa Zheng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, new sum-of-sinusoids statistical simulation models are proposed for Rayleigh fading channels. These new models employ random path gain, random initial phase, and conditional random Doppler frequency for all individual sinusoids. It is shown that the autocorrelations and cross correlations of the quadrature components, and the autocorrelation of the complex envelope of the new simulators match the desired ones exactly, even if the number of sinusoids is as small as a single-digit integer. Moreover, the probability density functions of the envelope and phase, the level crossing rate, the average fade duration, and the autocorrelation of the squared fading …

Adaptive Neural Network Based Power System Stabilizer Design, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Power system stabilizers (PSS) are used to generate supplementary control signals for the excitation system in order to damp the low frequency power system oscillations. To overcome the drawbacks of conventional PSS (CPSS), numerous techniques have been proposed in the literature. Based on the analysis of existing techniques, this paper presents an indirect adaptive neural network based power system stabilizer (IDNC) design. The proposed IDNC consists of a neuro-controller, which is used to generate a supplementary control signal to the excitation system, and a neuro-identifier, which is used to model the dynamics of the power system and to adapt the …