Engineering Commons^™

Wave Propagation In Nanofibers, Xiangfa Wu, Yuris A. Dzenis

Nebraska Center for Materials and Nanoscience: Faculty Publications

Surface effect on the longitudinal and flexural wave propagation in straight nanofibers/nanowires is studied within the framework of continuum mechanics. Modified Euler-Bernoulli and Rayleigh-Love rod equations and modified Timoshenko beam equation were developed to take into account the surface effect. It was found that surface tension/stress plays appreciable influence on the wave propagation in nanofibers/nanowires at very small diameters. Wave dispersion relations were presented in closed form, and numerical calculations were performed to show the variation of the phase velocity with the wave number at varying surface property and fiber diameter. The given results can be used as the theoretical …

Evidence Of Long-Wavelength Collective Excitations In Magnetic Superlattices, Nikolay I. Polushkin, Steven A. Michalski, Lanping Yue, Roger D. Kirby

Materials Research Science and Engineering Center: Faculty Publications

We report on a mechanism of dynamic dipolar coupling in magnetic superlattices via long-wavelength nonevanescent fields. In the spin excitation spectra of our heterophase stripe structures, such interactions mediate a singlet ↔ doublet crossover in the frequency regime driven by the orientation of an external static field. This crossover is a new feature observed in collective behavior of superlattices, though there is some analogy of this phenomenon with birefringence taking place in optical superlattices. We envision applying the collective effects described here in microwave photonic devices.

Design And Implementation Of A Modular Wireless Sensor Network Sniffer, John C. Mceachen, Teo Hong Siang, Georgios Kirykos

U.S. Navy Research

We present the design and implementation of a wireless packet sniffing application focused on the communications of TinyOS-based sensor networks. This modular, multi-threaded application allows robust analysis of transmitted frames in an easily understood format similar to tcpdump. The underlying software framework is presented and details of the implementation are discussed. Finally, verification of the application is performed using a basic TinyOS application.

A Comparison Of Optimized Link State Routing With Traditional Ad-Hoc Routing Protocols, Pore Ghee Lye, John C. Mceachen

U.S. Navy Research

The performance of mobile ad-hoc networks (MANET) is related to the efficiency of the routing protocols in adapting to frequently changing network topology and link status. This paper addresses the issue by comparing the relative performance of three key ad-hoc routing protocols: Destination-sequenced Distance Vector (DSDV), Ad-hoc Ondemand Distance Vector (AODV) and Optimized Link State Routing (OLSR). The protocols are tested based on two scenarios, namely, tactical networks for ships and sensor-based network nodes. Four performance metrics were measured by varying the maximum speed of mobile hosts, network size and traffic load, to assess the routing capability and protocol efficiency. …

Single-Sided Crash Cushion System, John D. Reid, John R. Rohde, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A single-sided crash attenuation cushion system having an impact head and three stage energy absorption mechanism. The energy absorbing mechanism has a mandrel for deforming thin-walled tubes in a controlled collapse to absorb impact forces from a colliding vehicle. The third stage of the absorption mechanism includes an additional deformable compressible tube between the fixed-object hazard and the thin walled tubes.

Acuta Enews December 2006, Vol. 35, No. 12

ACUTA Newsletters

In This Issue

From the President.................. Carmine Piscopo, Providence College

Board Report............... Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

DC Update.................. Jeanne Jansenius, Sewanee, The University of the South

FYI: Useful Information from the Campus...................... Student Monitor

Pumping Up PoE............................ GaryAudin, Delphi, Inc.

Site to See

Web Tip: Website Recognition Program........... Aaron Fuegrer, ACUTA Information Technology Manager

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

Thanks to Exhibitors for 2006

Welcome New Member

An Energy Efficient Mac-Phy Approach To Support Distributed Source Coding In Wireless Sensor Network, Wei Wang, Dongming Peng, Honggang Wang, Hamid Sharif, Beata J. Wysocki, Tadeusz A. Wysocki

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

Distributed Source Coding (DSC) based signal processing applications are ideal candidates for multirate transmissions in Wireless Sensor Network (WSN). In this paper, we propose a novel MAC-PHY approach in WSN to achieve energy efficiency using multirate desirable for the DSC based signal processing applications. Our approach is different from the common multirate research in link adaptation, the focus of which is to increase throughput based on rate adaptation derived from variable channel conditions. In the proposed approach, the redundant and inefficient communications are eliminated, yielding significant improvement of energy efficiency in WSN. Here, the minimum desirable transmission power can be …

Capacity Of Single-Radio Ad Hoc Networks For Handling High Bit-Rate Real-Time Internet Applications, Mehran Abolhasan, Tadeusz A. Wysocki, Daniel Franklin, Justin Lipman

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

Until now, the main focus in ad hoc networking has been improving Routing and Medium Access Control (MAC) Strategies. As a result, a diverse range of routing and MAC protocols have been proposed. To evaluate these protocols, much of the existing research has been based on simulation scenarios which assume ideal channel conditions and low node and traffic densities. Therefore, despite a few studies which have shown the performance limitations of ad hoc networks theoretically, there has not been many simulation studies performed which investigate the performance of ad hoc networks under a high node and traffic density. This paper …

Direct Sequence Modified Time Hopping Ppm Over Ultra Wideband S-V Channel, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki

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

A three position Pulse Position Modulation (PPM) scheme is proposed for a Direct Sequence Time Hopping Ultra Wideband wireless communication system. The channel is based on the Saleh-Valenzuela model. We show that by adapting the Space Time Spreading technique to use three pulse positions in a single input single output system representing -2,0,2 an improvement in Bit Error Rate is achieved compared to sending the same bits using two pulse positions only. In addition, the bit access rate is doubled as two bits can be successfully sent in the same time using our proposed system.

Material Selection And Design Consideration For Moisture Damage Of Asphalt Pavement, Jamilla Emi Sudo Lutif, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.

Effect Of Nb And C Additives On The Microstructures And Magnetic Properties Of Rapidly Solidified Sm-Co Alloys, S. Aich, Jeffrey E. Shield

Nebraska Center for Materials and Nanoscience: Faculty Publications

Highly coercive Sm-Co-based permanent magnets have been achieved through simple modification of binary Sm_{12Co88 alloys with Nb, C or combined Nb and C at concentrations ranging from 1 to 10 atomic percent processed via rapid solidification. Melt spinning at 40 m/s resulted in the formation of the metastable TbCu7-type structure in all alloys. While the unalloyed, as-solidified Sm12Co88 alloy displayed a coercivity of 0.5 kOe, alloying additions resulted in a systematic and profound increase in coercivity. Nb additions resulted in as-solidified coercivities up to 9 kOe, C additions up to 37 kOe, and combined NbC …}

Krf Excimer Laser-Assisted Combustion-Flame Deposition Of Diamond Films, Y. X. Han, Hao Ling, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Cobalt (Co) composition has detrimental effects on the deposition of diamond films on cemented tungsten carbide (WC-Co) substrates. It decreases adhesion of the deposited films to the substrates and causes a transformation of sp³-bonded diamond to sp²-bonded graphite. In this study, a KrF excimer laser with a wavelength of 248 nm, a pulse width of 23 ns, and a pulse energy range of 84–450 mJ was used in the combustion-flame method to improve the quality of the deposited diamond films. Scanning electron microscopy, energy dispersive x-ray analysis, and Raman spectroscopy of the deposited films showed that …

Developing Institutional Faculty Communities To Review And Assess Sotl Work, Paul Savory, Amy Nelson Burnett, Amy M. Goodburn

Department of Industrial and Management Systems Engineering: Faculty Publications

This workshop explores theoretical questions and practical strategies for how to develop faculty peer reviewers for SOTL work. After reading a set of faculty case-study files that include varying forms of SOTL work, participants will engage in guided discussion about reviewing and assessing such work and about developing faculty communities equipped to do such work. Presenter(s) also will seek feedback on guidelines that they have developed for external reviewers of SOTL work. Many teaching efforts have focused primarily on engaging faculty to participate in SOTL initiatives, with little attention to creating mechanisms for evaluating and assessing the work resulting from …

Department Of Biological Systems Engineering Newsletter, Issue 2, November 2006

BSE Department Magazine

Contents:
Visiting Scholar
Big changes in the BSE Computer Lab
From the Department Head
National Science Foundation Initiative Moving to Transform Water and Environment Research ByWayneWoldt
ASABE Awards
Nebraska Tractor Test Lab Welcomes New Director
Alumni News
August Graduation
College of Agricultural Sciences and Natural Resources Alumni Association (CASNRAA)
Hydrologic Studies in Prairie and Agricultural Watersheds Gleanings from a Faculty Development Leave by Dean E. Eisenhauer
Irrigation and Energy Conservation Field Day By Suat Irmak
P3–Ten Years
Hall of Fame
Vegetative Treatment Systems Help Small Livestock Producers Control Animal Waste by Kalee Olson
Ice Cream Social & Scholarship Recognition
Student …

Acuta Enews November 2006, Vol. 35, No. 11

ACUTA Newsletters

In This lssue

Legislative/Regulatory Scorecard tor 2006.............. Jeri A. Semer, CAE, ACUTA Executive Director

ACUTA Presents Open-Source lP Telephony Audio Seminar

Tech Talk: A Communications Method Respected by lts Peers.................. Kevin Tanzillo, Dux PR

DC Update............... Jeonne Jansenius, University of the South

FYI: Useful lnformation from the Campus................... Student Monitor

Board Report...................... Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

lT Disaster Recovery: Why Plan?.................. Mike Grunder, Vantage Technology

Web Tip: What's New?..................... Aaron Fuehrer, ACUTA lnformation Technology Manager

lnfo Links................... Randy Hayes, Univ. of Northern lowa

IEEE 10 Gb/s Ethernet Standards Approved. Hugo Draye, Fluke Networks (Reprinted from BICSI …

Multi-User Uwb-Ir Systems With Interleaved Coding-Modulation On Multipath Fading Channels, Michal M. Pietrzyk, Keni Popovski, Tadeusz Wysocki, Beata J. Wysocki, Jos H. Weber

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

Interleaved coding-modulation (ICM) is a recently proposed method for ultra-wideband impulse radio (UWBIR) systems. ICM exploits the concept of chip interleaving, allowing to alleviate the problem of inter-symbol and inter-pulse interference commonly present in high data rate UWB-IR systems. In this paper, we extend previous work on ICM to scarcely populated multi-user scenarios. We propose a design of a deterministic chip interleaver based on time-hopping hyperbolic congruence sequences. We also review the main parameters of the random and hyperbolic interleavers. Our results indicate that the proposed type of interleaver yields similar performance to random interleavers but with the advantage of …

Incorporation Of Polyethylene Glycol Into Self-Assembled Monolayers Enhances Substrate-Mediated Gene Delivery By Nonspecifically- Bound Complexes, Angela K. Pannier, Lonnie D Shea

Department of Biological Systems Engineering: Conference Presentations and White Papers

Developing systems capable of controlled and efficient gene transfer is a fundamental goal of biotechnology, with applications including functional genomics, gene therapy, and tissue engineering. Substrate-mediated delivery, also termed solid phase delivery, describes the immobilization of DNA, complexed with nonviral vectors, to a biomaterial or substrate through specific or nonspecific interactions. Cells cultured on the substrate are exposed to elevated DNA concentrations within the local microenvironment, which enhances transfection. We investigated transfection resulting from DNA complexes immobilized to a substrate through specific interactions introduced through complementary functional groups on the vector and surface or through nonspecific interactions. Self-assembled monolayers (SAMs) …

Crumb Rubber In Performance-Graded Asphalt Binder, Wayne Jensen, Magdy Abdelrahman

Nebraska Department of Transportation: Research Reports

No abstract provided.

Effects Of Middle Plane Curvature On Vibrations Of A Thickness-Shear Mode Crystal Resonator, J. S. Yang, Xiaomeng Yang, Joseph A. Turner, John A. Kosinski, Robert A. Pastore, Weiping Zhang

Department of Engineering Mechanics: Faculty Publications

We study the effects of a small curvature of the middle plane of a thickness-shear mode crystal plate resonator on its vibration frequencies, modes and acceleration sensitivity. Two-dimensional equations for coupled thickness-shear, flexural and extensional vibrations of a shallow shell are used. The equations are simplified to a single equation for thickness-shear, and two equations for coupled thickness-shear and extension. Equations with different levels of coupling are used to study vibrations of rotated Y-cut quartz and langasite resonators. The influence of the middle plane curvature and coupling to extension is examined. The effect of middle plane curvature on normal acceleration …

Fast And Efficient Generation Of Influenza A Virus Like Particles From Synthetic Genes, Theresa Schinko, Harutha Thaisuchat, Hendrik J. Viljoen, Nisha Padhye, Reingard Grabherr

Hendrik J. Viljoen Publications

Co-transfection of bacmids resulted in the generation of influenza A virus like particles in the supernatant of Sf9 cells. VLPs were purified by means of Sucrose gradient centrifugation and the expected results were confirmed by Electron microscopy, Western Blot analysis and hemagglutination assays.

Engineering@Nebraska - Fall 2006

Engineering@Nebraska (Alumni Magazine)

Table of Contents:

From the Dean
Faculty Profile—It’s Easy Being Green (and Red): Roger Hoy, new director of the Tractor Test Lab, is making sure the 87-year-old operation still meets the needs of today’s industry.
Front and Center
We’ve Got Your Back: Sixty members of the Class of 2010 begin their college careers at a two-day camp just for engineers.
COVER STORY: Where Are The Rest?: Despite increased recruitment efforts, women still comprise only 12 percent of the college’s student body. What has gone wrong, and how can we improve?
Leading By Example: Engineering and architecture students lobby for environmentally …

Role Of Atomic Scale Interfaces In The Compressive Behavior Of Carbon Nanotubes In Composites, S. Namilae, Namas Chandra

Department of Engineering Mechanics: Faculty Publications

Carbon nanotubes (CNT) are potentially promising fibers for ultra high strength composites. In order to fully har-ness the outstanding mechanical properties of carbon nanotubes as fiber reinforcements, it is essential to understand the nature of load transfer between fiber and matrix under various types of loading conditions that include tension, compression, torsion and a combination thereof. In this paper, we study the compressive behavior (buckling and post-buckling) of carbon nanotubes in the neat form, when they are embedded in polyethylene matrix and with in¬terface chemical modifications using molecular dynamics simulations based on Tersoff–Brenner potential. It is ob¬served that the critical …

Acuta Enews October 2006, Vol. 35, No. 10

ACUTA Newsletters

ln This lssue

VoWl-Fi? VoWiMAX? Why Not? Why Wait?................ Ray Horak, The Context Corporation

From the President: Strategic Planning.................... Carmine Piscopo, Providence College

Tech Talk: Taking the Pulse of Our Network Security................. Kevin Tanzillo, Dux PR

DC Update.............. Jeanne Jansenius, University of the South

lnfo Links...................... Randy Hayes, Univ. of Northern lowa

FYI: Useful lnformation from the Campus Student Monitor

Board Report................ Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

Web Tip: Telecom Listserv Changes Aaron Fuehrer, ACUTA lnformation Technology Manager

ACUTA Conference-Some Thoughts and Highlights 30 Years Out.... Mike Grunder, Vantage Technology

Welcome New Members

Committee Profile: Program Committee

Modeling And Simulation Of The Interaction Between Lubricant Droplets On The Slider Surface And Air Flow Within The Head/Disk Interface Of Disk Drives, Lin Wu

Department of Mechanical and Materials Engineering: Faculty Publications

The dynamic interaction phenomenon between three-dimensional (3-D) lubricant droplets located on the air bearing surface and air flow within the head-disk interface is modeled and numerically simulated. A strong interaction is observed for ultra low flying slider design. The droplet motion and deformation are able to induce non-negligible air bearing force and moment change, which in turn may impose a non-negligible disturbance on the slider’s flying attitude.

Thermal Analysis Of The Vortex Tube Based Thermocycler For Fast Dna Amplification: Experimental And Two-Dimensional Numerical Results, V. Raghavan, Scott E. Whitney, Ryan J. Ebmeier, Nisha V. Padhye, Michael Nelson, Hendrik J. Viljoen, George Gogos

Hendrik J. Viljoen Publications

In this article, experimental and numerical analyses to investigate the thermal control of an innovative vortex tube based polymerase chain reaction (VT-PCR) thermocycler are described. VT-PCR is capable of rapid DNA amplification and real-time optical detection. The device rapidly cycles six 20 μl 96 bp λ-DNA samples between the PCR stages (denaturation, annealing, and elongation) for 30 cycles in approximately 6 min. Two-dimensional numerical simulations have been carried out using computational fluid dynamics (CFD) software FLUENT v.6.2.16. Experiments and CFD simulations have been carried out to measure/predict the temperature variation between the samples and within each sample. Heat transfer rate …

Optical Emission In Magnetically Confined Laser-Induced Breakdown Spectroscopy, X. K. Shen, Yongfeng Lu, T. Gebre, Hao Ling, Y. X. Han

Department of Electrical and Computer Engineering: Faculty Publications

Magnetically confined laser-induced breakdown spectroscopy was investigated by studying the optical emission from laser-induced plasma plumes expanding across an external transverse magnetic field. KrF excimer laser pulses with a pulse duration of 23 ns and a wavelength of 248 nm were used to produce plasmas from Al, Cu, and Co targets. Various optical emission lines obtained from Al and Cu targets show an obvious enhancement in the intensity of optical emission when a magnetic field of ~0.8 T is applied, while the optical emission lines from Co targets show a decrease in the optical emission intensity. The enhancement factors of …

Acuta Enews September 2006, Vol. 35, No. 9

ACUTA Newsletters

ln This lssue

Prepaid Calling Cards

From ACUTA Headquarters: Looking Ahead................. Jeri A. Semer, CAE, ACUTA Executive Director

Tech Talk: As a Framework, lTlL Leads the Way.............. Kevin Tanzillo, Dux PR

DC Update............ Jeanne Jansenius, University of the South

Wiretaps: lnterpreting the Constitution Becomes a Controversy............. Pat Scott, ACUTA Comm. Mgr.

Board Report.............. Riny Ledgerwood, San Diego State Univ. ACUTA Sec./Treasurer

ACUTA One-Day Workshop: Making Convergence Work

Be a State/Province Coordinator............ Mary Lou Emmons, lndiana Univ., Bloomington

lnfo Links................ Randy Hayes, Univ. of Northern lowa

More Winners from ACUTA Annual Conference

Your Site Could Be a Site to See

Welcome …

Acuta Enews September 2006, Vol. 35, No. 9

ACUTA Newsletters

ln This lssue

Prepaid Calling Cards

From ACUTA Headquarters: Looking Ahead...................... Jeri A. Semer, CAE, ACUTA Executive Director

Tech Talk: As a Framework, lTlL Leads the Way................ Kevin Tanzillo, Dux PR

DC Update................ Jeanne Jansenius, University of the South

Wiretaps: lnterpreting the Constitution Becomes a Controversy.............. Pat Scott, ACUTA Comm. Mgr.

Board Report............... Riny Ledgerwood, San Diego State Univ. ACUTA Sec./Treasurer

ACUTA One-Day Workshop: Making Convergence Work

Be a State/Province Coordinator........... Mary Lou Emmons, lndiana Univ., Bloomington

lnfo Links................... Randy Hayes, Univ. of Northern lowa

More Winners from ACUTA Annual Conference

Your Site Could Be a Site to See

Welcome …

Jecp—A Java Electron Crystallography Project, Xingzhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

JECP stands for a java electron crystallography project that includes a series of practical java stand-alone programs for electron diffraction/microscopy and crystallography applications. The aim of the JECP project is twofold, i) as teaching tools to show students the principles of electron diffraction/microscopy and crystallography, ii) as research tools to analyze experimental results. Although there are commercial and public domain computer programs available that allow a user to simulate electron diffraction patterns or processing HREM images, there are always situations when we need to perform operations that are not a feature of any of the existing programs. The programs in …

The Doe Consortium For Research On Enhancing Carbon Sequestration In Terrestial Ecosystems: Fy 2007-2011 Five Year Science Plan, U.S. Department Of Energy

US Department of Energy Publications

The DOE Consortium for Research on Enhancing Carbon Sequestration in Terrestrial Ecosystems (CSiTE) conducts multi-scale research to acquire basic knowledge for underpinning the implementation of soil carbon (C) sequestration in an environmentally acceptable and economically feasible manner. Research is based on the premise that identifying and understanding the basic mechanisms controlling sequestration across managed and unmanaged ecosystems are fundamental to developing approaches for enhancing C capture and long-term storage. The goal is to discover and characterize links among physical, chemical, and biological processes controlling soil C dynamics and storage at a mechanistic level to facilitate the enhancement of C storage …