Engineering Commons^™

Method For Performing Accelerated Characterization Of Viscoelastic Constitutive Behavior Of Asphaltic Concrete, Curtis Berthelot, D. H. Allen, Chad Searcy

Department of Engineering Mechanics: Faculty Publications

Constitutive models based in continuum mechanics are formulated for modeling the time dependent mechanical re¬sponse of asphaltic concrete. The model chosen for the initial phase of study is linear viscoelastic, resulting in stress-strain re¬lations that are of the single integral Boltzmann type in time. Experimental equipment and testing protocols are described for obtaining material properties within the viscoelastic framework selected for characterization. A frequency sweep experimental technique is described for obtaining composite properties from short-term tests that can be used to predict long-term, time-depen¬dent material behavior. Mathematical techniques are described for converting experimentally obtained complex compliances to creep compliances and …

Acuta Enews October 2003, Vol. 32, No. 10

ACUTA Newsletters

In This Issue

From the President.................... Walter L. Czerniak, President

Fire Safety: Should Cables Have a Warning Label?.......................... Frank Bisbee &, Diane Santarelli

ACUTA Board Report....................... Jeri semer, ACUTA Executive Director

Tech Talk.................. Kevin Tanzillo, Dux Public Relations

DC Update Whitney Johnson, Retired, Northern Michigan Univ.

ACUTA: Help Yourself to a Buffet of Benefits!

Welcome New Members

Development Of A Design Guideline For Phase Construction Of Steel Girder Bridges, Atorod Azizinamini

Nebraska Department of Transportation: Research Reports

No abstract provided.

Use Of Computer Spreadsheets And Paper-Based Workbooks To Teach Comprehensive Nutrient Management Planning, Charles A. Shapiro, R. L. Deloughery, Richard K. Koelsch, M. K. Kucera, Charles S. Wortmann

Department of Biological Systems Engineering: Papers and Publications

The objective of this program was to provide producers and ag advisors the skills needed to apply for and maintain the non-engineering components of a Nebraska permit to operate a livestock waste control facility. This includes a Comprehensive Nutrient Management Plan (CNMP). Eighty six producers and advisors participated in an intensive three-session hands-on class with a total of nine contact hours at four sites in eastern Nebraska in the spring of 2002. The workshop included lecture and participant use of spreadsheet tools to assist with performing the necessary calculations. With an average of 68 % responses per session, 58% rated …

Fact Sheet #2: Do I Need A Npdes Permit For My Livestock Or Poultry Operation, Richard K. Koelsch

Department of Biological Systems Engineering: Conference Presentations and White Papers

New U.S. Environmental Protection Agency (EPA) rules that took effect April 14, 2003 indicate that animal feeding operations (AFOs) can be defined as concentrated animal feeding operations (CAFOs) and required to obtain a National Pollutant Discharge Elimination System (NPDES) permit from the EPA or a designated state permitting authority. The likelihood of an AFO being classified as a CAFO will depend, in large part, on whether that operation is considered to be large, medium, or small.

Winter Operations, Abrasives And Salt Brine, Geza Pesti, Yu Liu

Nebraska Department of Transportation: Research Reports

The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road surface. However, because of some undesired side effects, such as corrosion and damage to the environment, salt and abrasives may need to be supplemented by other substances in some areas. Powerful non-corrosive acetate-based chemicals have been considered by several agencies, but their high price has limited their use. Recent research has focused on the use of new, less corrosive, and highly effective …

Phosphorus Management, Bahman Eghball, J.F. Shanahan, Gary E. Varvel, John E. Gilley

Department of Biological Systems Engineering: Papers and Publications

Soils with high levels of P can contribute to excess P in runoff and subsequently pollute the surface water. Excess P in the soil can be removed from the system by harvesting crops. The objectives of this study were to evaluate corn (Zea mays L.) P removal effects on soil P reduction, and to evaluate various corn hybrids and soybean [Glycine max (L.) Merr.] varieties for differences in grain P concentration and P removal. Soil with varying P levels as a result of annual or biennial beef cattle (Bos Taurus) feedlot manure or compost application was …

Toward Development Of A Steel Bridge System - Simple For Dead Load And Continuous For Live Load, Atorod Azizinamini, Aaron Jon Yakel, Nick J. Lampe

Nebraska Department of Transportation: Research Reports

No abstract provided.

Progress In The Development Of A Recombinant Vaccine For Human Hookworm Disease: The Human Hookworm Vaccine Initiative, Peter J. Hotez, Bin Zhan, Jeffrey M. Bethony, Alex Loukas, Angela Williamson, Gaddam Narsa Goud, John M. Hawdon, Azra Dobardzic, Reshad Dobardzic, Kashinath Ghosh, Maria Elena Bottazzi, Susana Mendez, Bernard Zook, Yan Wang, Sen Liu, Idong Essiet-Gibson, Sophia Chung-Debose, Shuhua Xiao, David Knox, Michael Meagher, Mehmet Inan, Rodrigo Correa-Oliviera, Paul Vilk, Herman R. Shepherd, Walter Brandt, Philip K. Russell

Michael Meagher Publications

Hookworm infection is one of the most important parasitic infections of humans, possibly outranked only by malaria as a cause of misery and suffering. An estimated 1.2 billion people are infected with hookworm in areas of rural poverty in the tropics and subtropics. Epidemiological data collected in China, Southeast Asia, and Brazil indicate that, unlike other soil-transmitted helminth infections, the highest hookworm burdens typically occur in adult populations, including the elderly. Emerging data on the host cellular immune responses of chronically infected populations suggest that hookworms induce a state of host anergy and immune hyporesponsiveness. These features account for the …

Plasticized, Antiplasticized And Crystalline Conducting Polymers And Precursors Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Materials containing precursors to electrically conductive polymers and electrically conductive polymers are described which have a high degree of crystallinity. The high degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. High levels of electrical conductivity are achieved in the electrically conductive materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriental film which has isotropic electrical conductivity.

Two Semi-Infinite Interfacial Cracks Between Two Bonded Dissimilar Elastic Strips, Xiangfa Wu, Yuris A. Dzenis, Tian-You Fan

Department of Engineering Mechanics: Faculty Publications

The complex stress intensity factor and energy release rate are obtained for two semi-infinite interfacial cracks between two bonded dissimilar elastic strips with equal thickness under inplane deformations. During the procedure, by means of conformal mapping technique, the mixed boundary-value problem is reduced to a standard Riemann–Hilbert problem, which is further solved in closed-form. In some limiting cases, the present explicit solutions can cover the well-known results in the literature.

Acuta Enews September 2003, Vol. 32, No. 9

ACUTA Newsletters

In This Issue

32nd Annual Conference Highlights

ACUTA Members' Needs and Preferences................ Jeri Semer, CAE, Executive Director

ACUTA Board Report Carmine Piscopo, Providence College

Provisioning: lt Really Has Nothing To Do with Vitttes................. Kevin Tarzillo, Dux Public Relations

New Additions to Telecommunications Relay Services (2).................. Dave Ostrom, Washington State Univ

Winners, Winners, Winners!

DC Update................ Whitney Johnson, Retired, Northern Michigan Univ

ACUTA Member Sites to See

Welcome Mew Members

Finite-Temperature Anisotropy Of Ptco Magnets, Ralph Skomski, Arti Kashyap, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

The temperature dependence of the magnetocrystalline anisotropy of PtCo and its atomic origin are investigated by first-principle and model calculations. The Pt spin moment necessary to realize the leading 5d anisotropy contribution is due to neighboring Co atoms. At finite temperatures, Co spin disorder strongly reduces the Pt moment and the anisotropy. This is in contrast to the situation encountered in 3d and 3d–4f magnets, where the atomic magnetic moments remain largely conserved, even above the Curie temperature. A consequence of the L1₀ mechanism is that theK₁ (T) curve of exhibits a negative curvature, in contrast to the …

Exchange Interactions And Curie Temperature Of Y–Co Compounds, Arti Kashyap, Ralph Skomski, Renat F. Sabiryanov, Sitaram Jaswal, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

The Curie temperature of rare-earth Co intermetallics is investigated by self-consistent spin-polarized electronic-structure calculations on Y–Co compounds. The total exchange interaction of a given site with all other sites (J_o) is calculated by the linear-muffin-tin-orbital method using the local force theorem and employed to obtain mean-field Curie-temperature estimates. The theoretical predictions for YCo₃, YCo₅, and Y₂Co₁₇ are in fair agreement with the experimental Curie temperatures. For YCo₅, the variation of exchange interactions (J_ij) with distance is analyzed, and it is discussed how the presence of nonequivalent cobalt …

Atomic Force Acoustic Microscopy Methods To Determine Thin-Film Elastic Properties, D.C. Hurley, K. Shen, N.M. Jennett, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

We discuss atomic force acoustic microscopy (AFAM) methods to determine quantitative values for the elastic properties of thin films. The AFAM approach measures the frequencies of an AFM cantilever’s first two flexural resonances while in contact with a material. The indentation modulus M of an unknown or test material can be obtained by comparing the resonant spectrum of the test material to that of a reference material. We examined a niobium film (d=280±30 nm) with AFAM using two separate reference materials and two different cantilever geometries. Data were analyzed by two methods: an analytical model based on conventional …

Characteristics Of Phototrophic And Non-Phototrophic Lagoons For Swine Manure, Tongtong Chen, Dennis D. Schulte, Richard K. Koelsch, Anne M. Parkhurst

Department of Biological Systems Engineering: Papers and Publications

Odors are a major result of inadequately sized and mismanaged anaerobic lagoons. However, purple or pink colored lagoons, indicating the presence of phototrophic purple bacteria, are less likely to be an odor nuisance than are non–purple lagoons. Eight swine lagoons were studied to quantify critical parameters thought to allow purple lagoons to be a more reliable odor control alternative. Bacteriochlorophyll a (Bchl a), which indirectly measures the abundance of phototrophic bacteria, was greater in purple lagoons than in non–purple lagoons (P = 0.01). Oxidation–reduction potential (ORP) was less negative for purple lagoons than for non–purple lagoons in both spring …

Elastic Wave Propagation And Scattering In Solids With Uniaxially Aligned Cracks, Liyong Yang, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

In this article, elastic wave propagation and scattering in a solid medium permeated by uniaxially aligned penny-shaped microcracks are studied. The crack alignment refers to the case in which the unit normals of all cracks are randomly oriented within a plane of isotropy. The analysis is restricted to the limit of the noninteraction approximation among individual cracks. Explicit expressions for attenuations and wave speeds of the shear horizontal, quasilongitudinal, and quasishear vertical waves are obtained using stochastic wave theory in a generalized dyadic approach. The ensemble average elastic wave response is governed by the Dyson equation, which is solved in …

Acuta Enews August 2003, Vol. 32, No. 8

ACUTA Newsletters

In This Issue

Key Words for the Coming Months.................Walter Czerniak, Northern Illinois University

Wi or Wi Not? Taking Wireless to the Max..................... Kevin Tanzillo, Dux Public Relations

New Additions to Telecommunications Relay Service................. Dave Ostrom, Washington State Univ.

DC Update..................... Whitney Johnson, Retired, Northern Michigan Univ.

Board Report................... John Bradley, Rensselaer Polytechnic lnstitute

Welcome New Members

Design And Development Of A Low-Cost High Range Resolution X-Band Radar, Paul C. Cantu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Synthetic Aperture Radar (SAR) is one of the main tools for microwave remote sensing because of its multi-dimensional high resolution characteristics and the capability to operate in nearly all weather conditions, day and night. The University of Nebraska-Lincoln (UNL) initiated the design and development of a low-cost airborne SAR in January 2001 to support our Airborne Remote Sensing Program. The objectives of this project are separated into various evolutionary stages. This thesis will focus on the initial phase of design and construction of an X-band high range resolution radar (HRR) using basic RF /microwave and digital components. The following stages …

Local Applications Of The National Livestock And Poultry Environmental Stewardship Curriculum, Diane Huntrods, Richard K. Koelsch, Frank Humenik

Department of Biological Systems Engineering: Conference Presentations and White Papers

This paper introduces the LPES curriculum project, summarizing the curriculum development process, the final curriculum materials, and the outreach activities. Following an overview of the LPES Curriculum Impact Survey, the authors will present representative examples of uses and modifications made of the LPES curriculum as it is used with targeted audiences. This model for utilizing national expertise to address state and local educational needs may have benefit in other extension education programs as land grant university resources decrease. The paper concludes with a discussion of lessons learned from this national extension education curriculum development effort.

Oscillatory Interlayer Exchange Coupling And Its Temperature Dependence In [Pt/Co]3/Nio/[Co/Pt]3 Multilayers With Perpendicular Anisotropy, Z. Y. Liu, Shireen Adenwalla

Materials Research Science and Engineering Center: Faculty Publications

Interlayer exchange coupling that oscillates between antiferromagnetic and ferromagnetic as a function of NiO thickness has been observed in [Pt(5 Å)/Co(4 Å)]₃/NiO(t_NiO Å)/[Co(4 Å)/Pt(5 Å)]₃ multilayers with out-of-plane anisotropy. The period of oscillation corresponds to ~2 monolayers of NiO. This oscillatory behavior is possibly attributed to the antiferromagnetic ordering in NiO. The antiferromagnetic interlayer exchange coupling for the 11 Å NiO layer shows an increase in coupling strength with increasing temperature, in agreement with the quantum interference model of Bruno for insulating spacer layers. A coexistence of exchange biasing and antiferromagnetic interlayer exchange coupling has …

Closely Linear Temperature Dependence Of Exchange Bias And Coercivity In Out-Of-Plane Exchange-Biased [Pt/Co] 3/Nio (11 Å) Multilayer, Z.Y. Liu, Shireen Adenwalla

Materials Research Science and Engineering Center: Faculty Publications

Strong out-of-plane exchange biasing has been observed in out-of-plane exchange biased [Pt (5 Å)/Co (4 Å)] ₃/NiO (11 Å) multilayer with perpendicular easy axis. Both the exchange field H_E and coercivity H_C display a closely linear temperature dependence except at very low temperatures. A thin NiO layer coated on the top of a Pt/Co multilayer has a great effect on the domain pattern of the Pt/Co multilayer, which is in a more irregular configuration with much smaller domain sizes than the uncoupled Pt/Co multilayer. A simulation according to Malozemoff's random field model gives a good agreement to …

Progress In Spectroscopic Ellipsometry: Applications From Vacuum Ultraviolet To Infrared, James N. Hilfiker, Corey L. Bungay, Ron A. Synowicki, Thomas E. Tiwald, Craig M. Herzinger, Blaine Johs, Greg K. Pribil, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Spectroscopic ellipsometry (SE) is a noncontact and nondestructive optical technique for thin film characterization. In the past 10 yr, it has migrated from the research laboratory into the semiconductor, data storage, display, communication, and optical coating industries. The wide acceptance of SE is a result of its flexibility to measure most material types: dielectrics, semiconductors, metals, superconductors, polymers, biological coatings, and even multilayers of these materials. Measurement of anisotropic materials has also made huge strides in recent years. Traditional SE measurements cover the ultraviolet, visible, and near infrared wavelengths. This spectral range is now acquired within seconds with high accuracy …

Moving Screw Dislocations In Piezoelectric Bimaterials, Xiangfa Wu, Yuris A. Dzenis, Wen-Sheng Zou

Department of Engineering Mechanics: Faculty Publications

An explicit solution for a moving screw dislocation in a piezoelectric bimaterial is given by means of complex variables. The electroelastic fields and forces acting on the moving dislocation are obtained in closed form. As special cases, solutions for a moving screw dislocation in a piezoelectric half-plane with a free or rigid surface are obtained explicitly.

Acuta Enews July 2003, Vol. 32, No. 7

ACUTA Newsletters

In This Issue

ACUTA Elects New Board of Directors

Congratulations to Milestone Members............................ Jeri Semer, CAE, Executive Director

lnfiniBand Aims to lmprove Data Center Performance........................ Kevin Tanzillo, Dux Public Relations

Comm. College Leverages lT Resources................. Christine J. Holley, lnteractive lntelligence, lnc.

Be a State/ Province Coordinator!............. Harvey Buchanan, Chair, ACUTA Membership Committee

ACUTA Board Report............................ John Bradley, Rensselaer Polytechnic Institute

DC Update.................... Whitney Johnson, Retired, Northern Michigan Univ.

Welcome New Members

Publications Committee Needs a Few Good Members

Comment On: 'Depolarization Corrections To The Coercive Field In Thin-Film Ferroelectrics', Stephen Ducharme, Vladimir Fridkin

Stephen Ducharme Publications

The Letter by Dawber et al. [J. Phys.: Condens. Matter 15 L393 (2003)] notes that incomplete screening in the electrodes of a ferroelectric capacitor can result in an underestimate for the true coercive field in films of nanometer thickness. We show that their estimate of the magnitude of this correction it too large in the case of ferroelectric copolymer Langmuir- Blodgett films and, as a result, invalidates the claim that finite-size scaling of the ferroelectric coercive field is evident in films thinner than 15 nm.

Characterization And Optimization Of A Chromatographic Process Based On Ethylenediamine-N,N,N′,N′-Tetra(Methylphosphonic) Acid-Modified Zirconia Particles, Sabyasachi Sarkar, Peter W. Carr, Clayton V. Mcneff, Anuradha Subramanian

Papers in Biotechnology

The primary objective of work was to characterize, optimize and model a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid (EDTPA)-modified zirconia particles. Zirconia particles were produced by spray-drying colloidal zirconia. Zirconia spheres produced were further classified, calcined and modified with EDTPA to yield a solid-phase support for use in bio-chromatography (r_PEZ). Specifically, the ability of r_PEZ to selectively bind and enrich IgG, IgA, and IgM from biological fluids was evaluated and demonstrated. To better understand the force of interaction between the IgG and the r_PEZ, the equilibrium disassociation constant (Kd) was determined by static binding isotherms, as a function of temperature …

Optical Communications By Frequency Content Of Femtosecond Laser Pulses, Dennis Alexander, Mark L. Rohlfs

Department of Electrical and Computer Engineering: Faculty Publications

A free-space optical communications System is provided capable of transmitting data over long distances through the atmosphere. The communications System according to the present invention comprises an optical transmitter at a first location, the optical transmitter comprising a femtosecond pulsed laser Source for producing a train of femtosecond laser pulses. The optical transmitter further comprises a laser pulse width modulator to provide a pulse width modulated train of femtosecond laser pulses corresponding to the data being transmitted. The communications System further com prises an optical receiver at a Second location for receiving the modulated train of femtosecond laser pulses. The …

Jun 2003, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Rehabilitation of Behlen Building Test Car Location Inside Insulation

Interfacial Edge Crack Between Two Bonded Dissimilar Orthotropic Strips Under Antiplane Point Loading, Xiangfa Wu, Yuris A. Dzenis, Wen-Sheng Zou

Department of Engineering Mechanics: Faculty Publications

A closed-form solution is obtained for the interfacial edge crack between two bonded dissimilar orthotropic strips loaded by antiplane point loading in form of screw dislocation or line force. Conformal mapping and existing dislocation solutions are utilized for constructing the fundamental solution of the problem. The stress intensity factor (SIF) and the energy release rate(ERR) are obtained explicitly.