Engineering Commons^™

Phase-Field Modeling Of The Formation Of Lamellar Nanostructures In Diblock Copolymer Thin Films Under Inplanar Electric Fields, Xiang-Fa Wu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

Recent experiments show that external inplanar electric field can be employed to guide the molecular self-assembly in diblock copolymer (BCP) thin films to form lamellar nanostructures with potential applications in nanotechnology. We study this self-assembly process through a detailed coarse-grained phase separation modeling. During the process, the free energy of the BCP films is modeled as the Ginzburg-Landau free energy with nonlocal interaction and electrostatic coupling. The resulting Cahn-Hilliard (CH) equation is solved using an efficient semi-implicit Fourier-spectral algorithm. Numerical results show that the morphology of order parameter formed in either symmetric or asymmetric BCP thin films is strongly influenced …

Test007: Case 20-30, Tractor Museum

Case-New Holland

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Methods To Prioritize Placement Of Riparian Buffers For Improved Water Quality, M. D. Tomer, Michael G. Dosskey, Michael R. Burkart, Matthew J. Helmers, Dean E. Eisenhauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying and mapping locations where agroforestry buffers can effectively improve water quality. One technique employs soil survey information to rank soil map units for how effectively a buffer, when sited on them, would trap sediment from adjacent cropped fields. Results allow soil map units to be compared for relative effectiveness of buffers …

Genome Sequencing And Analysis Of The Biomass-Degrading Fungus Trichoderma Reesei (Syn. Hypocrea Jecorina), Diego Martinez, Randy M. Berka, Bernard Henrissat, Markku Saloheimo, Mikko Arvas, Scott E. Baker, Jarod Chapman, Olga Chertkov, Pedro M. Coutinho, Dan Cullen, Etienne G. J. Danchin, Igor V. Grigoriev, Paul Harris, Melissa Jackson, Christian P. Kubicek, Cliff S. Han, Isaac Ho, Luis F. Larrondo, Alfredo Lopez De Leon, Jon K. Magnuson, Sandy Merino, Monica Misra, Beth Nelson, Nicholas Putnam, Barbara Robbertse, Asaf A. Salamov, Monika Schmoll, Astrid Terry, Nina Thayer, Ann Westerholm-Parvinen, Conrad L. Schoch, Jian Yao, Ravi Barabote, Mary Anne Nelson, Chris Detter, David Bruce, Cheryl R. Kuske, Gary Xie, Paul Richardson, Daniel S. Rokhsar, Susan M. Lucas, Edward M. Rubin, Nigel Dunn-Coleman, Michael Ward, Thomas Brettin

United States Department of Energy: Publications

Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to depolymerize biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. We assembled 89 scaffolds (sets of ordered and oriented contigs) to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models. Unexpectedly, considering the industrial utility and effectiveness of the carbohydrate-active enzymes of T. reesei, its genome encodes fewer cellulases and hemicellulases than any other sequenced fungus able to hydrolyze plant cell wall polysaccharides. Many T. reesei genes encoding carbohydrate-active enzymes are distributed nonrandomly in …

Ice Breaking Exercice: Group Resume For Faculty, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

Resumes typically describe an individual’s accomplishments. This ice breaking exercise for faculty asks that faculty explore their incredible array of talents and experiences and create a single group resume to allow you to become acquainted with your fellow faculty participants.

Modeling Of Thermodynamically Coupled Reaction-Transport Systems, Yaşar Demirel

Yaşar Demirel Publications

Nonisothermal reaction-diffusion systems control the behavior of many transport and rate processes in physical, chemical and biological systems, such as pattern formation and chemical pumps. Considerable work has been published on mathematically coupled nonlinear differential equations by neglecting thermodynamic coupling between a chemical reaction and transport processes of mass and heat. This study presents the modeling of thermodynamically coupled system of a simple elementary chemical reaction with molecular heat and mass transport. The thermodynamic coupling refers that a flow occurs without or against its primary thermodynamic driving force, which may be a gradient of temperature or chemical potential or reaction …

Acuta Enews May 2008, Vol. 37, No. 5

ACUTA Newsletters

ln This Issue

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

Two Audio Seminars in May

Tech Talk: Femtocells: Designed to Give Cellular Coverage a Boost........................ Kevin Tanzillo, Dux PR 3

Board Approves State of Nominees

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

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

Recycle Old Cell Phones

Be a Telecom BMOC: Win Big Buck

Check lt Out: RFls/RFPs, Job Postings, Press Releases

lnfo links.................. Randy Hayes' Univ. of Northern lowa

Be a Moderator or Monitor at the Annual Conference..... Donna Hall, ACUTA Mgr. of Professional …

2008 Epa’S Report On The Environment

United States Environmental Protection Agency: Publications

To accomplish its mission, the U.S. Environmental Protection Agency (EPA) must pay close attention to trends in the condition of the nation’s air, water, and land, and to associated trends in human exposure and health and the condition of ecological systems. Data on environmental trends serve two key purposes: they provide valuable input to EPA in developing its strategic outlook and priorities, and they allow EPA and the public to assess whether the Agency is succeeding in its overall mission to protect human health and the environment. EPA prepared this Report on the Environment (ROE) to accomplish these purposes.
In …

Tractor Inventory, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Digital Media Agco Challenger, Nebraska Tractor Test Lab

Nebraska Tractor Tests

Images and videos of the 2008 Agco Challenger Tractor Testing.

Proctor Compaction Testing, Joshua Connelly, Wayne Jensen, Paul Harmon

Nebraska Department of Transportation: Research Reports

No abstract provided.

Artificial Neural Network Estimation Of Soil Erosion And Nutrient Concentrations In Runoff From Land Application Areas, Minyoung Kim, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The transport of sediment and nutrients from land application areas is an environmental concern. New methods are needed for estimating soil and nutrient concentrations of runoff from cropland areas on which manure is applied. Artificial Neural Networks (ANNs) trained with a backpropagation (BP) algorithm were used to estimate soil erosion, dissolved P (DP) and NH₄–N concentrations of runoff from a land application site near Lincoln, Nebraska, USA. Simulation results from ANN-derived models showed that the amount of soil eroded is positively correlated with rainfall and runoff. In addition, concentrations of DP and NH₄–N in overland flow …

Cellular Arrays (Us Patent Application), Angela K. Pannier, Eric A. Ariazi, V. Craig Jordan, Lonnie D. Shea

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The present invention relates to characterizing transcription within cells. In particular, the present invention provides transfected cell arrays (e.g., two-dimensional and/or three-dimensional arrays) and systems, kits and methods utilizing the same (e.g., for transcriptional activity characterization). Compositions and methods of the present invention find use in, among other things, research, drug discovery and clinical (e.g., diagnostic, preventative and therapeutic) applications.

Narrow Grass Hedge Effects On Nutrient Transport Following Compost Application, John E. Gilley, Bahman Eghball, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The placement of stiff‐stemmed grass hedges on the contour along a hillslope has been shown to decrease nutrient transport in runoff. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted beef cattle manure was applied at dry weights of 0, 68, 105, 142, and 178 Mg ha^-1 to a silty clay loam soil and then incorporated by disking. Soil samples were collected 243 days later for analysis of water‐soluble phosphorus (WSP), Bray and Kurtz No. 1 phosphorus (Bray‐1 P), NO …

Developing Lcfs For Biofuels: Getting It Right For Corn Ethanol, Kenneth Cassman, Adam Liska

Adam Liska Papers

• Corn ethanol will be first to test the newly developed LCFS assessment methods; substantial amounts of other biofuels will come several years later

• Accurate valuation of direct-effect GHG emissions from corn ethanol is the foundation of the LCFS process; these affects vary with ethanol biorefinery type and corn feedstock supply

• Different reference GHG emissions values are needed for each major class of ethanol plants

• The BESS model provides the most up-to-date, scientifically sound estimate of corn-ethanol GHG emissions; can BESS and GREET reach agreement?

• Certification and compliance tools are also needed

The Quest For Stronger, Tougher Materials: A Letter And A Response, Robert O. Ritchie, Yuris A. Dzenis

Nebraska Center for Materials and Nanoscience: Faculty Publications

Dr. Ritchie writes: "The perspective “Structural Nanocomposites” (Y. Dzenis, 25 January, p. 419) describes a quest for improved structural materials and indicates that composites with nanoscale reinforcements would have “exceptional mechanical properties.” Is this true?

Why would reinforcements that are small in size or volume offer any particular benefit over larger-scale reinforcements? As the Perspective correctly asserts, if the composite material is to be used for a small-volume structure, clearly the reinforcements must also be small. In addition, small-volume reinforcements are stronger, as has been known since the early days of research on whiskers (1). In this regard, reinforcement by …

Implementing Mass Nutrient Balance Procedures On Swine Production Facilities, Richard Koelsch, Alan Sutton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Whole Farm Nutrient Balance (WFNB) approaches have been used to provide a measure of environmental performance (Aarts et al., 1992; Lanyon and Beegle, 1993; Klausner, 1995). Whole farm balance concepts are used as part of the Netherlands Mineral Accounting System public policy that includes compulsory mineral input and output reports from livestock farms and levies for excess imbalances (Jongbloed and Lenis, 1998). Procedures for measuring WFNB will be followed in measurements made on commercial swine facilities for 2006 and 2007. The conclusions developed based upon data from 13 for 2006 include:

• On average, the participating swine producers import 1.5 units …

Acuta Enews April 2008, Vol. 37, No. 4

ACUTA Newsletters

ln This lssue

From the President..................Walt Magnussen, Texas A&N Univ., ACUTA President

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

Campus Safety Legislation Mulled in Wake of Shootings ......Raymond Thrower, Jr., IACLEA

Tech Talk: We'll Ask Again: ls This a Phone You Want on Your Network? Kevin Tanzillo, Dux PR

12th Annual Strategic Leadership Forum Topics

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

Nominate Now for ACUTA Ruth A. Michalecki Award

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

Welcome New Members

Check lt Out: RFls/RFPs, Job Postings, Press Releases

Interfaces, Volume 10, Issue 1 - Spring 2008

INTERFACES: Newsletter of the Nebraska Center for Materials and Nanoscience

CONTENTS
From the Director
Facility Focus: Nano-Fabrication Facility
Recent Achievements of Center Researchers
Magnetic Nanoclusters Put in Order – Insights with Scanning Tunneling Microscopy
NCMN Welcomes Eva Franke Schubert
Research Spotlight: Barry Cheung
UNL Hosts 54th Annual Midwest Solid State Conference
Published Books
Engineers Part of $9 Million Project Studying Cell Context of Genes

Free-Edge Stresses And Progressive Cracking In Surface Coatings Of Circular Torsion Bars, Xiang-Fa Wu, Yuris A. Dzenis, Kyle W. Strabala

Department of Engineering Mechanics: Faculty Publications

This paper considers the explicit solutions of free-edge stresses near circumferential cracks in surface coatings of circular torsion bars and their application in determining the progressive cracking density in the coating layers. The problem was formulated within the framework of linear elastic fracture mechanics (LEFM). The free-edge stresses near crack tip and the shear stresses in the cross-section of the torsion bar were approached in explicit forms based on the variational principle of complementary strain energy. Criterion for progressive cracking in the coating layer was established in sense of strain energy conservation, and the crack density is thereby estimated. Effects …

Engineering@Nebraska - Spring 2008

Engineering@Nebraska (Alumni Magazine)

Table of Contents:

Front & Center
Engineering Students Enjoy Spain Firsthand: With Nebraska Engineering’s focus on international education, “live and learn” happens in amazing settings. Warm up to the wonders of winter break in Spain.
Spring Break at 35,000 Feet: Nebraska Engineering’s undergraduate research reaches new heights in service to NASA. Ride along with blog posts from an uplifting experience in microgravity.
UNL Experts Build Better Bridges: Atorod Azizinamini—professor of Civil Engineering, researcher and director of UNL's National Bridge Research Organization (NABRO)—leads a team in applying a $2 million grant for safer spans.
Tiny Fibers, Huge Potential: The longterm research …

Development Of A Stand-Alone Concrete Bridge Pier Protection System, Scott Rosenbaugh, Ronald K. Faller, Jason A. Hascall, Robert W. Bielenberg, Karla A. Polivka, John R. Rohde, Dean L. Sicking, Erin M. Allison

Nebraska Department of Transportation: Research Reports

No abstract provided.

Subcritical And Supercritical Droplet Evaporation Within A Zero-Gravity Environment: Low Weber Number Relative Motion, Hongtao Zhang, Vasudevan Raghavan, George Gogos

Department of Mechanical and Materials Engineering: Faculty Publications

A validated comprehensive axisymmetric numerical model, which includes the high pressure transient effects, variable thermo-physical properties and inert species solubility in the liquid phase, has been employed to study the evaporation of moving n-heptane droplets within a zero-gravity nitrogen environment, for a wide range of ambient pressures and initial freestream velocities. At the high ambient temperature considered (1000 K), the evaporation constant increases with the ambient pressure. At low ambient pressure, the evaporation constant becomes almost a constant during the end of the lifetime. At high ambient pressures, the transient behavior is present throughout the droplet lifetime. The final penetration …

An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Tapioca starch, poly(lactic acid) and Cloisite 30B nanocomposites foams, with clay contents of 1, 3, 5 and 7% (w/w), were prepared by a meltintercalation method. Multiple inputs single output models were developed to predict radial expansion ratio, unit density, bulk compressibility and spring index of the nanocomposite foams. An individual ANFIS model was developed for each mechanical property using clay content, temperature, pressure and torque as input parameters. All models preformed well with R² values > 0.71. All models had very low root mean squared error values.

Tailoring Magnetic Anisotropy At The Ferromagnetic/Ferroelectric Interface, Chun-Gang Duan, Julian P. Velev, Renat F. Sabirianov, Wai-Ning Mei, Sitaram Jaswal, Evgeny Y. Tsymbal

Nebraska Center for Materials and Nanoscience: Faculty Publications

It is predicted that magnetic anisotropy of a thin magnetic film may be affected by the polarization of a ferroelectric material. Using a Fe/BaTiO₃ bilayer as a representative model and performing first-principles calculations, we demonstrate that a reversal of the electric polarization of BaTiO₃ produces a sizable change in magnetic anisotropy energy of Fe films. Tailoring the magnetic anisotropy of a nanomagnet by an adjacent ferroelectric material may yield entirely new device concepts, such as electric-field controlled magnetic data storage.

System For Reducing Stress Induced Effects Duringdetermination Of Fluid Optical Constants, Thomas E. Tiwald, John A. Woollam, Galen L. Pfeiffer, Blaine D. Johs, Craig M. Herzinger

Department of Electrical and Computer Engineering: Faculty Publications

A system for determination of optical constants of liquids, including provision for reducing stress induced effects while obtaining data.

Experimental Characterization Of The Impact-Damage Tolerance Of A Cross-Ply Graphite-Fiber/Epoxy Laminate, Xiang-Fa Wu, Goutam Ghoushal, Mikhail Kartashov, Zuleyha Aslan, Joseph A. Turner, Yuris A. Dzenis

Xiang-Fa Wu Publications

In this study, the impact-damage tolerance of a graphite-fiber/epoxy composite laminate is studied by examining the correlation between the impact force and the resulting delamination area in the laminate. The cross-ply [0₂/90₂/0₂]_s composite laminate was made of thermosetting P7051S-20Q-1000 prepregs (Toray Composites America). A Hopkinson pressure bar (HPB) was employed to create the impulsive loading with varying magnitude. Transient impact force, displacement, impact power, and transmitted impact energy were calculated using the transient signals recorded from the strain gage mounted on the HPB. Impulsive loads with controllable magnitude were used to induce delamination …

Temperature Dependence Of Half-Metallic Hybridization Gaps, Ralph Skomski

Ralph Skomski Publications

The temperature dependence of the spin polarization of half-metallic ferromagnets is investigated by model calculations. Emphasis is on changes in the density of states, especially on the closure of the hybridization gap. The Stoner-type calculation yields a simple one-electron expression for the gap as a function of temperature and a corresponding transition temperature T*, above which the spin polarization is drastically reduced. The small parameter determining the finite-temperature breakdown of the spin splitting is the width of the hybridization gap relative to other bandwidth parameters. The model predictions are consistent with the experiment and with first-principles electronic structure calculations, …

Fabrication Of Nanostructures With High Electrical Conductivity On Silicon Surfaces Using A Laser-Assisted Scanning Tunneling Microscope, Kaijun Yi, Z. Y. Yang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Nanostructures with high electrical conductivity were fabricated on silicon surfaces using a laser-assisted scanning tunneling microscope (LA-STM). The nanostructures, dots and lines, were fabricated on H-passivated p-doped silicon (110) surfaces. By precisely controlling the experimental conditions such as pulse energy and tip-surface gap distance, feature sizes (dot diameters and line widths) and heights of the fabricated nanostructures could be controlled. For instance, a dot with a diameter of 30 nm and a line with a width of 30 nm were obtained. In addition, scanning tunneling microscopy investigation of the structures revealed that their band gaps were changed during the …

Surgical Camera Robot: United States Patent No. Us 7,339,341 B2, Dmitry Oleynikov, Shane Farritor, Mark E. Rentschler, Stephen R. Platt, Jason Dumpert

Department of Mechanical and Materials Engineering: Faculty Publications

The present invention is a miniature camera robot which can be placed entirely within an open space such as an abdominal cavity. The instant camera robot has pan and tilt capabilities, an adjustable focus camera, and a support component for supporting the robot body. In particular embodiments, the camera robot further contains a light source for illumination and a handle to position the camera robot. A system and method for using the instant camera robot are also provided.