Engineering Commons^™

Engineering@Nebraska - Spring 2007

Engineering@Nebraska (Alumni Magazine)

Table of Contents:

From the Dean
Letters
Faculty Profile—Longtime Professor is a Student Again: Electrical engineering professor Khalid Sayood is taking science courses to learn how to use his expertise in data patterns for biomedical purposes.
Front and Center
A Little Luck, A Lot of Work: Three alumni share what it’s like to run their own companies.
COVER STORY: Rebuilding New Orleans: Construction faculty and students from Omaha are helping the Esplanade Ridge neighborhood recover from Hurricane Katrina.
Magic in the Making: Lance Pérez’s wireless sensor network could make it possible for more people to live independently after an accident …

2007 Survey Of Summer Sessions Students At The University Of Nebraska-Lincoln, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

During Summer 2007, UNL Summer Sessions (FlexEd) surveyed summer students to learn about their experience in taking a summer course(s). The survey results will offer confirmation of what we are doing well and will provide guidance on areas of improvement and better strategies for marketing UNL summer opportunities. A total of 227 students completed the survey. Fifteen summer classes were selected to complete a paper-based or electronic version of the survey. The classes were from three different summer sessions and used different delivery mechanisms (on-campus, studio, distance education).

Survey Of The Golden-Cheeked Warbler On Fort Hood In Support Of Nepa Requirements, Bruce Macallister, Tim Hayden, Michael Baranski, Rebecca Peak

United States Army Corps of Engineers, Omaha District

This research on the golden-cheeked warbler (GCW) was con-ducted on Fort Hood, Texas, during April and June 2006. Subject matter experts on Fort Hood were consulted and helped determine which areas of the installation contained suitable GCW habitat but were not already included in The Nature Conservancy’s intensive study program. Researchers then surveyed one of these areas, documenting the presence of GCW. This research was conducted to determine if data collected in the intensive study area has been successfully extrapolated to other areas of habitat on the installation.

The collected data showed that the territory density was lower than those …

Potential Of Agricultural Residues And Hay For Bioethanol Production, Ye Chen, Ratna R. Sharma-Shivappa, Deepak R. Keshwani, Chengci Chen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Production of bioethanol from agricultural residues and hays (wheat, barley, and triticale straws, and barley, triticale, pearl millet, and sweet sorghum hays) through a series of chemical pretreatment, enzymatic hydrolysis, and fermentation processes was investigated in this study. Composition analysis suggested that the agricultural straws and hays studied contained approximately 28.62–38.58% glucan, 11.19–20.78% xylan, and 22.01–27.57% lignin, making them good candidates for bioethanol production. Chemical pretreatment with sulfuric acid or sodium hydroxide at concentrations of 0.5, 1.0, and 2.0% indicated that concentration and treatment agent play a significant role during pretreatment. After 2.0% sulfuric acid pretreatment at 121°C/15 psi for …

Effect Of Ferroelectricity On Electron Transport In Pt/Batio3/Pt Tunnel Junctions, Julian P. Velev, Chun-Gang Duan, Kirill D. Belashchenko, Sitaram Jaswal, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

Based on first-principles calculations, we demonstrate the impact of the electric polarization on electron transport in ferroelectric tunnel junctions (FTJs). Using a Pt/BaTiO₃ /Pt FTJ as a model system, we show that the polarization of the BaTiO₃ barrier leads to a substantial drop in the tunneling conductance due to changes in the electronic structure driven by ferroelectric displacements. We find a sizable change in the transmission probability across the Pt/BaTiO₃ interface with polarization reversal, a signature of the electroresistance effect. These results reveal exciting prospects that FTJs offer as resistive switches in nanoscale electronic devices.

Calculations Of Spin-Disorder Resistivity From First Principles, Aleksander L. Wysocki, Kirill D. Belashchenko, Julian P. Velev, Mark Van Schilfgaarde

Nebraska Center for Materials and Nanoscience: Faculty Publications

Spin-disorder resistivity of Fe and Ni is studied using the noncollinear density functional theory. The Landauer conductance is averaged over random disorder configurations and fitted to Ohm’s law. The distribution function is approximated by the mean-field theory. The dependence of spin-disorder resistivity on magnetization in Fe is found to be in excellent agreement with the results for the isotropic s-d model. In the fully disordered state, spin-disorder resistivity for Fe is close to experiment, while for fcc Ni it exceeds the experimental value by a factor of 2.3. This result indicates strong magnetic short-range order in Ni at …

Enhanced Raman Scattering By Self-Assembled Silica Spherical Microparticles, Kaijun Yi, H. Wang, Yongfeng Lu, Z. Y. Yang

Department of Electrical and Computer Engineering: Faculty Publications

A technique was developed to achieve enhanced Raman scattering of the silicon photon modes using closely packed micro- and submicron silica spherical particles. Investigation on the particle-size dependence of Raman enhancement revealed that the strongest enhancement occurs when the particle diameter is equal to the spot size of the incident laser beam. Calculations using the OPTIWAVE^TM software based on the finite difference time domain algorithm under the perfectly matched layer boundary conditions were carried out. The results showed that photonic nanojets are formed in the vicinity outside the particles along the propagation direction of incident light. It was found …

Effect Of Backwashing On Perchlorate Removal In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

The influence of backwashing on biological perchlorate reduction was evaluated in two laboratory scale fixed bed biofilm reactors using 1- or 3-mm glass beads as support media. Influent perchlorate concentrations were 50 μg/L and acetate was added as the electron donor at a concentration of 2 mg C/L. Perchlorate removal was evaluated at various influent dissolved oxygen (DO) concentrations. Complete perchlorate removal was achieved with an influent DO concentration of 1 mg/L resulting in bulk phase DO concentrations below the detection limit of 0.01 mg/L. The influence of increasing influent DO concentrations for 12 h periods was evaluated before and …

Rotating Or Rotatable Compensator Spectroscopic Ellipsometer System Including Multiple Element Lenses, Blaine D. Johs, Martin M. Liphardt, Jeffrey S. Hale, Craig M. Herzinger, Steven E. Green, Ping He, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed are spectroscopic ellipsometer systems which include polarizer and analyzer elements which remain fixed in position during data acquisition, and at least one continuously rotating or step-wise rotatable compensator which transmits an electromagnetic beam therethrough and imposes a continuously variable or plurality of sequentially discrete polarization states on a beam of electromagnetic radiation; and at least one multiple element lens which also transmits the electromagnetic beam therethrough.

Determination Of Young’S Modulus Of Individual Electrospun Nanofibers, Philip A. Yuya, Yongkui Wen, Joseph A. Turner, Yuris A. Dzenis, Zheng Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

The authors report a technique for measuring Young’s modulus of a single electrospun nanofiber using the vibrations of two microcantilevers coupled with the nanofiber. The modulus is calculated from the resonant frequency shift resulting from the nanofiber. Polyacrylonitrile nanofibers (200 nm diameter) were collected during electrospinning and wrapped on two similar microcantilevers causing a shift in first resonance from 10.0 to 19.4 kHz. Finite element analysis was used to analyze the frequency shift using images from a scanning electron microscope giving a modulus of the as-spun polyacrylonitrile nanofiber of 26.8 GPa.

Analysis Of Fat Intake Based On The U.S. Department Of Agriculture’S 1994–96, 1998 Continuing Survey Of Food Intakes By Individuals (Csfii), U.S. Environmental Protection Agency

United States Environmental Protection Agency: Publications

Many chemicals found in the environment tend to accumulate in fatty tissue. Assessing potential risks from these chemicals in food requires knowledge of dietary habits and the amount of fat present in various types of foods. The National Center for Environmental Assessment of the U.S. Environmental Protection Agency’s (EPA’s) Office of Research and Development has conducted an analysis of fat consumption across the U.S. population. The analysis used data derived from the U.S. Department of Agriculture’s 1994–96 Continuing Survey of Food Intakes by Individuals (CSFII) and its 1998 Supplemental Children’s Survey and the EPA’s Food Commodity Intake Database (FCID). Percentiles …

Thermoeconomics Of Seasonal Latent Heat Storage System, Yaşar Demirel, H. Hüseyin Öztürk

Papers in Thermal Mechanics

A simple thermoeconomic analysis is performed for a seasonal latent heat storage system for heating a greenhouse. The system consists of three units that are a set of 18 packed-bed solar air heaters, a latent heat storage tank with 6,000 kg of technical grade paraffin wax as phase-changing material, and a greenhouse of 180m2. The cost rate balance for the output of a unit is used to estimate the specific cost of exergy for a yearly operation. Based on the cost rate of exergy, fixed capital investment, operating cost, and economic data, approximate cash-flow diagrams have been prepared. The systems …

Three Innovative Concepts For Short Span Steel Bridges, Aaron Jon Yakel, Atorod Azizinamini, Mohammadreza Farimani, Nazzanin Mossahebi

Nebraska Department of Transportation: Research Reports

No abstract provided.

Acuta Enews March 2007, Vol. 36, No. 3

ACUTA Newsletters

In This Issue

From ACUTA Headquarters Jeri A. Semer, CAE, ACUTA Executive Director

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

Liability When Employees Use Cell Phones White Driving............. Brendan Carr, Wiley Rein LLP

Telecom Managers Profit from VolP Knowledge .................. Gary Audin, Delphi, lnc.

Tech Talk: Time for a Change? Yes, and lt's March 11............... Kevin Tanzillo, Dux PR

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

lnvite Your Vendors to Join ACUTA

FYI: Useful lnformation from the Campus Student Monitor

Web Tip: New RFI/RFP Web Page............. Aaron Fuehrer, ACUTA lnformation Technology Manager

ACUTA …

Centerline Curbing Treatment At Railroad Crossings For Improved Safety, Aemal Khattak, Dwight L. Mosby Jr., Gregory Mcknight, Brian Gardner

Nebraska Department of Transportation: Research Reports

The objectives of this research were to study unsafe actions of motor vehicle drivers at railroadhighway grade crossings, to evaluate centerline barriers in reducing those unsafe driver actions, and to note any maintenance or other issues with the barriers. Driver actions were observed at two railroad crossings before and after installation of centerline barriers. A comparison of observed driver actions in the pre- and post-barrier periods provided information on the effectiveness of the barriers in reducing unsafe driver actions while periodic inspection of the centerline barriers provided information on maintenance needs. A major concern of the Nebraska Department of Roads …

Peer Review Of Teaching Project, Paul Savory, Amy M. Goodbrun, Amy Nelson Burnett

Department of Industrial and Management Systems Engineering: Faculty Publications

The national impact of UNL’s Peer Review of Teaching Project was recognized in 2005 – with a TIAA-CREF Hesburgh Certificate of Excellence – as an exceptional program in enhancing undergraduate student learning. In 2006, the project was designated an Institutional Leader by the Carnegie Foundation for the Advancement of Teaching and Learning. As a national institutional leader, the project will continue defining, measuring, tracking, and improving approaches that deepen student understanding.

Creating An Internet Repository For Course Portfolios, Paul Savory, Amy M. Goodburn, Amy Nelson Burnett

Department of Industrial and Management Systems Engineering: Faculty Publications

Our ITLE grant has supported the development of www.courseportfolio.org – an internet repository for faculty-written course portfolios documenting best practices and evidence of student learning occurring in the classroom.

Crop Residue Effects On Runoff Nutrient Concentrations Following Manure Application, Jeffrey E. Nicolaisen, John E. Gilley, Bahman Eghball, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure is applied to cropland areas managed under diverse conditions, resulting in varying amounts of residue cover. The objective of this study was to measure the effects of crop residue on nutrient concentrations in runoff from areas where beef cattle or swine manure were recently applied but not incorporated. Plots 0.75 m wide by 2 m long were established at the study site. Existing residue materials were removed, and corn, soybean, or winter wheat residue was added at rates of 2, 4, or 8 Mg ha⁻¹. Manure was then applied at rates required to meet estimated annual nitrogen …

Selective Assembly Of Nanoparticles On Block Copolymer By Surface Modification, Sanjun Niu, Ravi F. Saraf

Ravi Saraf Publications

We have developed a method to selectively deposit nanoparticles on the ordered nanoscale elements of PS–PI–PS (polystyrene– polyisoprene–polystyrene) block copolymer film. The process utilizes reactive ion plasma to selectively modify the PS surface with amine groups to electrostatically attract negatively charged Au nanoparticles. In spite of the strong interparticle Coulombic repulsion, the deposition on PS domains is significantly high. It is observed that the deposition at the edges of the domain is particularly high, forming a percolating nanoparticle necklace. The latter may lead to interesting avenues to fabricate electronic devices.

Spherical Silicon-Shell Photonic Band Gap Structures Fabricated By Laser-Assisted Chemical Vapor Deposition, H. Wang, Z. Y. Yang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Laser-assisted chemical vapor deposition was applied in fabricating three-dimensional (3D) spherical-shell photonic band gap (PBG) structures by depositing silicon shells covering silica particles, which had been self-assembled into 3D colloidal crystals. The colloidal crystals of self-assembled silica particles were formed on silicon substrates using the isothermal heating evaporation approach. A continuous wave Nd:YAG laser (1064 nm wavelength) was used to deposit silicon shells by thermally decomposing disilane gas. Periodic silicon-shell/silica-particle PBG structures were obtained. By removing the silica particles enclosed in the silicon shells using hydrofluoric acid, hollow spherical silicon-shell arrays were produced. This technique is capable of fabricating structures …

Wrinkling Of A Charged Elastic Film On A Viscous Layer, Xiang-Fa Wu, Yuris A. Dzenis, Kyle W. Strabala

Department of Engineering Mechanics: Faculty Publications

A thin metallic film deposited on a compliant polymeric substrate begins to wrinkle under compression induced in curing process and afterwards cooling of the system. The wrinkle mode depends upon the thin film elasticity, thickness, compressive strain, as well as mechanical properties of the compliant substrate. This paper presents a simple model to study the modulation of the wrinkle mode of thin metallic films bonded on viscous layers in external electric field. During the procedure, linear perturbation analysis was performed for determining the characteristic relation that governs the evolution of the plane-strain wrinkle of the thin films under varying conditions, …

Effect Of Oxygen Vacancies On Spin-Dependent Tunneling In Fe/Mgo/Fe, Julian P. Velev, Kirill D. Belashchenko, Sitaram S. Jaswal, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

First-principles calculations based on density functional theory are used to elucidate the effect of O vacancies, forming F centers, on spin-dependent tunneling in Fe/MgO/Fe(001) magnetic tunnel junctions. O vacancies produce occupied localized s states and unoccupied resonant p states, which is consistent with available experimental data. The authors find that O vacancies affect the conductance by nonresonant scattering of tunneling electrons causing a substantial reduction of tunneling magnetoresistance (TMR). Improving the quality of the MgO barrier to reduce O vacancy concentration would improve TMR in these and similar junctions.

Identification And Characterization Of Calcium And Manganese Transporting Atpase (Pmr1) Gene Of Pichia Pastoris, Michael P. Dux, Mehmet Inan

Papers in Biotechnology

A gene homologous to Saccharomyces cerevisiae PMR1 has been cloned in the methylotrophic yeast Pichia pastoris.The entire P. pastoris PMR1 gene (PpPMR1 ) codes a protein of 924 amino acids. Sequence analysis of the PpPMR1 cDNA and the genomic DNA revealed that there is no intron in the coding region. The putative gene product contains all of the conserved regions observed in P-type ATPases and exhibits 66.2%, 60.3% and 50.6% identity to Pichia angusta (Hansenula polymorpha), Saccharomyces cerevisiae PMR1 and human ATP2C1 gene products, respectively. A pmr1 null mutant strain of P. pastoris exhibited growth defects in media with the …

Acuta Enews February 2007, Vol. 36, No. 2

ACUTA Newsletters

In This Issue

Nominate Now for ACUTA Board of Directors 2007-08

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

Nominations Still Open for Institutional Excellence Awards............. Pat Todus, Northwestern Univ.

Tech Talk: Visibility for Your School and ACUTA............. Kevin Tanzillo, Dux PR

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

Overheard on the Listserv: Pricing VoIP

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

Web Tip: What's New on ACUTA Website...... Aaron Fuehrer, ACUTA Information Technology Manager

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

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

Remembering Harry Kyle …

Propagation Of Ultrashort Laser Pulses Through Water, Jianchao Li, Dennis R. Alexander, Haifeng Zhang, Ufuk Parali, David Doerr, John Clark Bruce Iii, Hao Wang

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, propagation of ultrashort pulses through a long 3.5 meter water channel was studied. Of particular interest was the attenuation of the beam at various lengths along the variable path length and to find an explanation of why the attenuation deviates from typical Beer Lambert law around 3 meters for ultrashort laser pulse transmission. Laser pulses of 10 fs at 75 MHz, 100 fs at 80 MHz and 300 fs at 1 KHz were employed to investigate the effects of pulse duration, spectrum and repetition rate on the attenuation after propagating through water up to 3 meters. Stretched …

Safety Performance Evaluation Of Minnesota's Temporary Rigid Panel Sign Stand Systems, Karla A. Polivka, James C. Holloway, Ronald K. Faller, John R. Rohde

Nebraska Department of Transportation: Research Reports

No abstract provided.

Design And Evaluation Of An Open Combination Traffic/Bicycle Bridge Railing System, Jason A. Hascall, John R. Rohde, Dean L. Sicking, Karla A. Polivka, Ronald K. Faller, James C. Holloway M.S.C.E., E.I.T.

Nebraska Department of Transportation: Research Reports

No abstract provided.

Granular Layers On Vibrating Plates: Effective Bending Stiffness And Particle-Size Effects, Wonmo Kang, Joseph A. Turner, Florin Bobaru, Liyong Yang, Kitti Rattanidit

Nebraska Center for Materials and Nanoscience: Faculty Publications

Acoustic methods of land mine detection rely on the vibrations of the top plate of the mine in response to sound. For granular soil (e.g., sand), the particle size is expected to influence the mine response. This hypothesis is studied experimentally using a plate loaded with dry sand of various sizes from hundreds of microns to a few millimeters. For low values of sand mass, the plate resonance decreases with added mass and eventually reaches a minimum without particle size dependence. After the minimum, a frequency increase is observed with additional mass that includes a particle-size effect. Analytical nondissipative continuum …

Tunneling Anisotropic Magnetoresistance Driven By Resonant Surface States: First-Principles Calculations On An Fe(001) Surface, Athanasios N. Chantis, Kirill D. Belashchenko, Evgeny Y. Tsymbal, Mark Van Schilfgaarde

Nebraska Center for Materials and Nanoscience: Faculty Publications

Fully relativistic first-principles calculations of the Fe(001) surface demonstrate that resonant surface (interface) states may produce sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single magnetic electrode. The effect is driven by the spin-orbit coupling. It shifts the resonant surface band via the Rashba effect when the magnetization direction changes. We find that spin-flip scattering at the interface is controlled not only by the strength of the spin-orbit coupling, but depends strongly on the intrinsic width of the resonant surface states.

Spectroscopic Ellipsometer And Polarimeter Systems, John A. Woollam, Blaine D. Johs, Craig M. Herzinger, Ping He, Martin M. Liphardt, Galen L. Pfeiffer

Department of Electrical and Computer Engineering: Faculty Publications

A spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, there being apertures before the stage for supporting a material system, and thereafter, the system being present in an environmental control chamber.