Engineering Commons^™

Implementation Of Warm-Mix Asphalt Mixtures In Nebraska Pavements, Yong-Rak Kim, Jun Zhang, Hoki Ban

Mid-America Transportation Center: Final Reports and Technical Briefs

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) were evaluated. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their HMA counterparts were implemented in Antelope County, Nebraska. More than one ton of field-mixed loose mixtures was collected at the time of paving and was transported to the NDOR and UNL laboratories to conduct comprehensive laboratory evaluations and pavement performance predictions of the …

Speed Limit Recommendation In Vicinity Of Signalized, High-Speed Intersection, Anuj Sharma Ph.D., Laurence Rilett Ph.D., Zifeng Wu M.S., Shefang Wang

Mid-America Transportation Center: Final Reports and Technical Briefs

This report presents the results of Nebraska Department of Roads (NDOR) research project SPR-P1 (11) M307, which evaluated the traffic operations and safety effects of 5 mph and 10 mph speed limit reductions in the vicinity of high-speed, signalized intersections with advance warning flashers (AWF). The methodology involved two studies: 1) field study of the impact of speed limit reduction at seven high-speed intersections, 2) crash analysis using the 10-year history from 28 high-speed intersections. In the field study, traffic operational effects of the reduced speed limits were analyzed for seven high-speed, signalized intersections with AWF, using the Quantile regression …

Assessing The Structural, Driver And Economic Impacts Of Traffic Pole Mounted Wind Power Generator And Solar Panel Hybrid System, Anuj Sharma Ph.D., Justice Appiah Ph.D., Scott K. Rosenbaugh

Mid-America Transportation Center: Final Reports and Technical Briefs

This project evaluates the physical and economic feasibility of using existing traffic infrastructure to mount wind power generators. Some possible places to mount a light weight wind generator and solar panel hybrid system are: i) Traffic signal pole and ii) Street Light pole. Traffic signal poles can themselves have multiple designs depending on type of mount (mast arm vs. span wire) and the width of the intersection (load carried) etc. The close proximity of street light poles and traffic signal poles to the traffic cabinets, which can be used for storing the battery banks, make them good candidates to mount …

Concrete Surface With Nano-Particle Additives For Improved Wearing Resistance To Increasing Truck Traffic, Genda Chen, Dongming Yan Ph.D., Chenglin Wu Ph.D., Nicholas Leventis Ph.D, Shruti Mahadik Ph.D., Zhibin Lin Ph.D

Mid-America Transportation Center: Final Reports and Technical Briefs

This study focused on the use of nanotechnology in concrete to improve the wearing resistance of concrete. The nano materials used were polymer cross-linked aerogels, carbon nanotubes, and nano-SiO2, nano-CaCO3, and nano-Al2O3 particles. As an indirect measurement of the concrete wearing resistance, the tensile and compressive properties and the permeability of concrete were evaluated for various mix designs. The optimal amount of nano material additives were determined following the American Society of Testing Methods (ASTM) standard test methodologies. The test results from the materials were compared for their mechanical behaviors. This type of technology may potentially improve the comfort level …

Pilot Study On Rugged Fiber Optic Brillouin Sensors For Large-Strain Measurements To Ensure The Safety Of Transportation Structures, Genda Chen, Zhi Zhou, Hai Xiao, Ying Huang

Mid-America Transportation Center: Final Reports and Technical Briefs

Brillouin-scattering Optical Time Domain Reflectometry (BOTDR) is a viable technology for simultaneous, distributed strain and temperature measurements for miles-long transportation structures. It is a promising tool to ensure the smooth operation and safety of bridge structures that are key links in surface transportation networks or between various transportation modes: i.e., from airport to train station. Currently, telecom-grade optical fibers are widely used in civil engineering for strain and temperature measurements. These fibers are very fragile and easy to break during installation and measurement. In order to understand the ultimate behavior of structures, more rugged optical fibers such as carbon/polyimide coated …

Use Of Fiber Bragg Grating (Fbg) Sensors For Performing Automated Bridge Pier Structural Damage Detection And Scour Monitoring, A.N. Thanos Papnicolaou Ph.D., Achilleas Tsakiris

Mid-America Transportation Center: Final Reports and Technical Briefs

The goal of this study was to evaluate the performance of Fiber Bragg Grating (FBG) sensors able to detect impacts with different frequencies on a bridge pier. The FBG technology was evaluated under controlled conditions in a laboratory flume set-up to mimic the flow, sediment, and design characteristics of a pier structure. The system was calibrated using site-specific properties to relate strain to a known magnitude force for different bridge pier designs, different scour depths, and structural impacts. The FBGs proved a reliable measure of strain and displacement for key components of bridge structures, such as piers, during varying flow …

Improving Freight Fire Safety: Experiment Testing And Computer Modeling To Further Development Of Mist-Controlling Additives For Fire Mitigation, Albert Ratner Ph.D., University Of Iowa

Mid-America Transportation Center: Final Reports and Technical Briefs

With the purpose to minimize or prevent crash-induced fires in road and rail transportation, the current interest in bio-derived and blended transportation fuels is increasing. Based on two years of preliminary testing and analysis, it appears to be clear that polymeric additives may be added to diesel fuel to mitigate the formation of fine mists while allow regular flow through the fuel system. In this work, computer modeling was adapted as a fast and cost-effective methodology to identify the target range where polymeric additives could impact the shear-thickening effect on fuels. The Volume of Fraction (VOF) method was used within …

Transportation Impacts Of The Chicago River Closure To Prevent An Asian Carp Infestation, Aaron Strong Ph.D., Nikhil Sikka Ph.D., Lindsay Salvatore Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

This project develops a simple linear programming model of the Upper Midwest regions rail transportation network to test whether a closure of the Chicago River to freight traffic would impact the capacity constraint of the rail system. The result suggest that the rail network in the Upper Midwest regions are nowhere near approaching capacity and that a closure would have little impact on the rail network. Two noteworthy sets of commodities may be adversely affected, cereal grains and other agricultural product and gravel and crushed stone.

Current-Based Diagnosis For Gear Tooth Breaks In Wind Turbine Gearboxes, Dingguo Lu, Xiang Gong, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Gearbox faults constitute a significant portion of all faults and downtime in wind turbines (WTs). Current-based gearbox fault diagnosis has significant advantages over traditional vibration-based techniques in terms of cost, implementation, and reliability. This paper derives a mathematical model for a WT drive train consisting of a twostage gearbox and a permanent magnet (PM) generator, from which the characteristic frequencies of gear tooth breaks in generator stator current frequency spectra are clearly identified. A adaptive signal resampling algorithm is proposed to convert the variable fault characteristic frequencies to constant values for WTs running at variable speeds. A fault detector is …

Energy Efficiency In Multiaccess Fading Channels Under Qos Constraints, Deli Qiao, Mustafa Cenk Gursoy, Senem Velipasalar

Department of Electrical and Computer Engineering: Faculty Publications

In this article, transmission over multiaccess fading channels under quality-of-service (QoS) constraints is studied in the low-power and wideband regimes. QoS constraints are imposed as limitations on the buffer violation probability. The effective capacity, which characterizes the maximum constant arrival rates in the presence of such statistical QoS constraints, is employed as the performance metric. A two-user multiaccess channel model is considered, and the minimum bit energy levels and wideband slope regions are characterized for different transmission and reception strategies, namely time-division multiple-access (TDMA), superposition coding with fixed decoding order, and superposition coding with variable decoding order. It is shown …

Matching And Funneling Light At The Plasmonic Brewster Angle, Christos Argyropoulos, Giuseppe D'Aguanno, Nadia Mattiucci, Neset Akozbek, Mark J. Bloemer, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

The ultrabroadband impedance matching of metallic gratings at the plasmonic Brewster angle [A. Al`u et al., Phys. Rev. Lett. 106, 123902 (2011)] is analyzed here in several realistic scenarios and configurations, and in the case of nonmonochromatic excitation. This phenomenon is the analogy of the well-known Brewster transmission for dielectric slabs but, when applied to plasmonic gratings, has the remarkable property of funneling and concentrating light within subwavelength slits. We analyze here how the presence of absorption and of realistic substrates and/or superstrates may influence the phenomenon, its beamwidth and angular selectivity, and its overall performance in the case …

Method For Increasing The Efficiency Of Organic Photovoltaic Cells, Jinsong Huang, Yongbo Yuan

Department of Mechanical and Materials Engineering: Faculty Publications

The present invention is directed to an organic photovoltaic cell that contains one or more dipole regions generally disposed between an organic active region and the electrodes and a process for producing such an organic photovoltaic cell.

Lte Phy Performance Analysis Under 3gpp Standards Parameters, Fahimeh Rezaei, Michael Hempel, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Long Term Evolution (LTE) has been introduced by 3GPP (3rd Generation Partnership Project) and is poised to dominate the 4th generation (4G) of mobile telecommunication networks. In this article, we present an in-depth analysis of the LTE physical layer’s characteristics and its performance. Our work is unique in providing a detailed performance study based on Release 8 of the 3GPP standard. Several works have discussed the LTE performance; however, most have been restricted to limited scenarios. Our work shows a more comprehensive investigation of the maximum data throughput under different conditions and scenarios. Our performance study includes TDD and FDD …

Modeling, Simulation, And Validation Of A Power Sic Bjt, Tanya Kirilova Gachovska, Jerry L. Hudgins, Angus Bryant, Enrico Santi, Alan Mantooth, Anant K. Agarwal

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents a physics-based model of a silicon carbide bipolar junction transistor and verification of its validity through experimental testing. The Fourier series solution is used to solve the ambipolar diffusion equation in the transistor collector region. The model is realized using MATLAB and Simulink. The experimental results of static operation and also the simulated and experimental results of switching waveforms are given.

A Multicell Battery System Design For Electric And Plug-In Hybrid Electric Vehicles, Taesic Kim, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The performance of electric vehicles (EVs) and plug-in hybrid electric vehicle (PHEVs) strongly relies on their battery storage system, which consists of multiple battery cells connected in series and parallel. However, cell state variations are commonly present, which reduces the energy conversion efficiency of the battery system. Furthermore, in a large battery system the risk of catastrophic faults of cells increases because a large numbers of cells are used. To solve these problems, this paper proposes a novel power electronics-enabled, self-X, multicell battery system design. The proposed battery system can self-heal from failures or abnormal operations of single or multiple …

Wind Speed And Rotor Position Sensorless Control For Direct-Drive Pmg Wind Turbines, Wei Qiao, Xu Yang, Xiang Gong

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a wind speed and rotor position sensorless control for wind turbines directly driving permanent magnetic generators (PMGs). A sliding-mode observer is designed to estimate the rotor position of the PMG by using the measured stator currents and the commanded stator voltages obtained from the control scheme of the machine-side converter of the PMG wind turbine. The rotor speed of the PMG (i.e., the turbine shaft speed) is estimated from its back electromotive force using a model adaptive reference system observer. Based on the measured output electrical power and estimated rotor speed of the PMG, the mechanical power …

Analog Sensing Front-End System For Harmonic Signal Classification, Daniel J. White, Peter William, Michael W. Hoffman, Sina Balkir, Nathan Schemm

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents the design of an Analog-to- Information spectral decomposition scheme suitable for parallel low-power analog and mixed-signal VLSI implementation. The novel scheme extracts sufficient information to achieve good back end signal detection and classification performance while using less power than purely digital spectral techniques such as FFT. Simulations of a prototype system in a mixed-signal 130nm CMOS process show a feasible solution space given an on-line self-calibrating system.

Permanent Magnet Generator Design And Control For Large Wind Turbines, Xu Yang, Dean Patterson, Jerry L. Hudgins

Department of Electrical and Computer Engineering: Faculty Publications

Direct drive permanent magnet generators(PMGs) are increasingly capturing the global wind market in large onshore and offshore applications. The aim of this paper is to provide a quick overview of permanent magnet generator design and related control issues for large wind turbines. Generator systems commonly used in wind turbines, the permanent magnet generator types, and control methods are reviewed in the paper. The current commercial PMG wind turbine on market is surveyed. The design of a 5 MW axial flux permanent magnet (AFPM) generator for large wind turbines is discussed and presented in detail.

Performance Analysis For Direction Of Arrival Estimating Algorithms, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Smart antennas have emerged as one of the most promising directions in supporting maximum communication link throughput. In this paper, we have investigated the impact of smart antennas on a complex mobile network such as a railroad wireless communications system. The objective is to analyze the selection of a Direction-Of-Arrival (DOA) estimation algorithm which provides the maximum efficiency when deployed in our railroad testbeds for wireless vehicular communication. Our findings are discussed to provide an indepth understanding of how different algorithms should be selected to support efficient network operations.

Quantitative Performance Analysis Of 3.65 Ghz Mobile Wimax, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

3.65 GHz Mobile WiMAX spectrum is often a better commercial solution due to its attractive licensing requirements, in spite of the slightly lower coverage area. However, no significant performance data has been reported for 3.65 GHz equipment behavior. In this paper, we have presented an in depth analysis of a 3.65 GHz Mobile WiMAX solution. Our reported data can also contribute in performing link budget analyses and benchmarking similar equipment.

Impact Of Wireless Communication Delay On Load Sharing Among Distributed Generation Systems Through Smart Microgrids, Song Ci, Junjie Qian, Dalei Wu, Ali Keyhani

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Load sharing among distributed generation systems (DGS) is one of the most important topics in wireless-enabled smart microgrids, where a set of power inverters at different geographical locations work coordinately and collaboratively through wireless networks to meet the load requirement. Parallel power inverters operated in distributed generation systems rely on the underlying wireless communication channels to exchange power information among them for load sharing control. However, existing work in the area of load sharing has largely ignored the effect of wireless communication delay. Study has shown that the time-varying wireless communication delay may have a significant impact on the performance …

Saturated–Unsaturated Flow In A Compressible Leaky-Unconfined Aquifer, Phoolendra Mishra, Velimir Vesselinov, Kristopher Kuhlman

United States Department of Energy: Publications

An analytical solution is developed for three-dimensional flow towards a partially penetrating largediameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The …

Business And Wealth Transfer In Nonmetropolitan Nebraska 2012 Nebraska Rural Poll Results, Rebecca J. Vogt, Cheryl A. Burkhart-Kriesel, Randolph L. Cantrell, Bradley Lubben, Odee Ingersoll, Shawn Kaskie

Rural Futures Institute: Publications

Includes

Executive Summary

Introduction

Businesses in the Community

Expected Number of Businesses in Local Community Five Years from Now by Community Size

Most Likely Outcome when Business Owner Leaves or Retires in Community

Business Exits and Transitions

Concern with Business Exits

Concern that Business Closings will Affect Ability to Get Needed Things by Occupation

Views of Community Strategies for Business Exits

Community Well-Being In Nonmetropolitan Nebraska 2012 Nebraska Rural Poll Results, Rebecca J. Vogt, Cheryl A. Burkhart-Kriesel, Randolph L. Cantrell, Bradley Lubben

Rural Futures Institute: Publications

Includes

Executive Summary

Trends in Community Ratings, 1996-2012

Community Change, 1996-2012

Expected Destination of Those Planning to Move: 1998-2012

Proportions of Respondents Very or Somewhat Satisfied with Each Service, 1997-2012

The Community and Its Attributes in 2012

Perceptions of Community Change by Community Size

Expected Community Change in Ten Years by Community Size

Satisfaction with Cellular Phone Service by Community Size

Difficulty or Ease of Leaving Community

Ease or Difficulty of Leaving Community by Length of Residence in Community

Feelings of Community Powerlessness by Community Size

Local Community Involvement Activities, 2002 and 2012

Distance from Goods and Services

Distance from …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2012, 132nd Anniversary Year, One Hundred-Twenty-Second Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Applied Science and Technology

Biological and Medical Sciences

Nebraska Wesleyan University Health and Sciences Graduate School Fair

Aeronautics and Space Science, Poster Session

Maiben Memorial Lecture: "The Status of Nebraska's Native Aspen," "Buffalo" Bruce McIntosh, Western Nebraska Resources Council

Aeronautics

Anthropology

Biological and Medical Sciences

Chemistry and Physics

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Earth Science

History/Philosophy of Science

Junior Academy, Senior High Competition

Teaching of Science and Math

Junior Academy, Junior High Competition

A Case-Crossover Study Of Laceration Injuries In Pork Processing, Lina Lander, Gary Sorock, Terry L. Stentz, Lynette Smith, Murray Mittleman, Melissa J. Perry

Department of Construction Engineering and Management: Faculty Publications

Objectives— The authors estimated the associations between transient risk factors and laceration injuries in workers at two meatpacking plants in the Midwest.

Methods— The case-crossover design was used to collect within-subject transient work task and personal-level exposure information. RRs of laceration injuries were estimated by comparing exposures during the ‘hazard’ period (just before the laceration injury) with exposures in the ‘control’ period (the previous workweek). Stratified analyses were utilized to estimate the effects of gender, ethnicity, training and the number of adjacent coworkers on each transient risk factor.

Results— The authors interviewed 295 meatpacking workers with laceration injuries (mean age …

P96. Three-Dimensional Morphometry Of Human Cervical Endplates, Rebecca A. Wachs, Victoria M. Michna, Eric H. Ledet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

BACKGROUND CONTEXT: Degeneration of the cervical intervertebral disc is the underlying cause for many patients suffering from neck and upper extremity pain. Anterior cervical discectomy and fusion, and cervical disc replacements are common, but next generation implants and less invasive surgical techniques are predicated on a comprehensive characterization of cervical endplate morphology. To date, cervical endplate morphometry has not been described in detail, and age-related and gender- dependent differences have not been characterized.

PURPOSE: The purposes of this research were to measure cervical endplate morphometry in both men and women across three decades of life and characterize age, gender, and …

Field Performance Evaluation Of A Ventilation System: A Swine Case Study, Jay D. Harmon, Michael C. Brumm, Larry D. Jacobson, Stephen H. Pohl, David R. Stender, Richard R. Stowell

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building and how they work as a system. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep‐pit swine finishing building with two 1,000‐head rooms. Exhaust fans connected to the manure pit and wall fans were operated at various stages as a negative‐pressure ventilation …

Kinect And 3d Gis In Archaeology, Heather Richards-Rissetto, Fabio Remondino, Jim Robersson, Jennifer Von Schwerin, Giorgio Agugiaro, Gabrio Girardi

Department of Anthropology: Faculty Publications

This paper explores the potential of using Microsoft's Kinect to create a low-cost and portable system to virtually navigate, through a prototype 3D GIS, the digitally reconstructed ancient Maya city and UNESCO World Heritage Site of Copan in Honduras. The 3D GIS, named QueryArch3D, was developed as part of the MayaArch3D project (http://mayaarch3d.unm.edu), which explores the possibilities of integrating databases and 3D digital tools for research and teaching on ancient architectures and landscapes. The developed system, based on the Flexible Action and Articulated Skeleton Toolkit (FAAST), controls in a remote and touchless mode the movements in the 3D environment in …

Acuta Enews January 2012 Vol. 41, No. 1

ACUTA Newsletters

ln This lssue...

1 Board Approves Slate of Nominees

2 From the President: New Building Network Designs at BC............ .--.Joseph Harrington, Boston College

3 Nominate a Colleague for the ACUTA Ruth A Michalecki Leadership Award

4 Member Benefit of the Month: Monthly Newsletter Subscriptions

4 Today's ACUTA for Today's CIO ................. Keith Fowlkes, UVA Wise

5 ACUTA Webinar: The Challenges of Mobile Connectivity

5 Board Report............... Riny Ledgerwood, SDSU

6 Info Links.............. .....Randy Hayes, Univ. of Northern Iowa

7 How Transdisciplinarity Will Help Workers Thrive ...................James Fraleigh, Apollo Research Institute

8 Committee Corner

8 Thanks to Event Sponsors in 2011 …