Engineering Commons^™

Trailer Mounted Bursting Energy Absorption System, John D. Reid, John R. Rohde, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A portable crash attenuation System having a trailer frame and an energy absorption mechanism attached thereto. The absorption mechanism has a first Stage pivotably connected to a Second Stage and the Second Stage is pivotably connected to the frame. By pivoting the Stages about hinges the attenuation System may be folded from an extended, deployed position or mode to a shortened transit mode for easy relocation of the entire attenuation System.

Solid-Like Dynamics In Ultrathin Films Of Polymeric Liquids, Gaurav Singh, Ravi F. Saraf, Yves Martin

Papers in Nanotechnology

In this letter, we demonstrate that, at mesoscales, nonferroelectric liquid films of polydimethyl siloxane. exhibit significant electrostriction not present in the corresponding bulk state. Remarkably, the observed electrostrictive effect has a response time ,20 ms in contrast to .5 ms recorded in conventional bulk ~ferroelectric polymers. The emergence of this fast electrostrictive strain in thin films is explained in terms of the amalgamation of two contrasting dynamic features—the influence of a highly mobile, viscous layer ~at the air/film interface. on the less-mobile, but fast responding, solid-like layer at the film/substrate interface. The effect is observed for thickness below 200 nm.

Manufacturing Of Novel Continuous Nanocrystalline Ceramic Nanofibers With Superior Mechanical Properties, Yuris A. Dzenis, Ruqiang Feng, Gustavo F. Larsen, Joseph Turner, Xiao Cheng Zeng

Papers in Nanotechnology

This project is in the area of nanomanufacturing of advanced nanostructured materials. Nanostructured materials (NSMs) with unusual and extreme properties will play a key role in many emerging technologies. However, manufacturing of NSMs with the desired properties is highly complex and currently is over-reliant on empirical data. In this project, a novel manufacturing process producing a new class of ceramic materials, i.e. continuous ceramic nanofibers, is addressed. The novel sol-gel electrospinning technique (patents pending), invented recently by two of the PI’s (Dzenis and Larsen), produces ceramic fibers of submicron diameters with potentially extreme thermomechanical properties. This technique is being analyzed …

Method For Forming An Antenna And A Radio Frequency Transponder, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A method is disclosed for forming an antenna and a radio frequency transponder. The method comprises the steps of (1) forming a paste comprising metal powder, polymeric material, and solvent; and (2) screening the paste through a screen onto a substrate. Additional steps couple electrical components to the paste and dry the paste.

Dec 2003, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Introductions Curator's Report Treasurer's Report

Spatiotemporal Databases: Models For Attracting Students To Research, Ágnes Bércesné Novák, Peter Revesz, Zsolt Tuza

CSE Conference and Workshop Papers

In higher education professors often make much effort to introduce their students to research. Unfortunately, the present standard database systems curriculum is composed of well-settled subjects that do not lead to research. The challenge is to bring the research frontier closer to students at beginner level. In this paper we describe how it can be done in the area of spatiotemporal databases. We propose a new database systems curriculum and illustrate its benefits by mentioning several highly succsesful student projects in some recent experimental introductory database systems courses that followed the new curriculum.

Magnetic Transitions In Disordered Gdal2, D. S. Williams, Paul M. Shand, Thomas M. Pekarek, Ralph Skomski, Valeri G. Petkov, Diandra Leslie-Pelecky

Materials Research Science and Engineering Center: Faculty Publications

The role of disorder in magnetic ordering transitions is investigated using mechanically milled GdAl₂. Crystalline GdAl₂ is a ferromagnet while amorphous GdAl₂ is a spin glass. Nanostructured GdAl₂ shows a paramagnetic-to-ferromagnetic transition and glassy behavior, with the temperature and magnitude of each transition dependent on the degree and type of disorder. Disorder is parametrized by a Gaussian distribution of Curie temperatures T_C with mean T_C and breadth Δ T_C. A nonzero coercivity is observed at temperatures more than 20 K above the highest T_C of any known Gd-Al phase; however, …

Self Assembled Nano-Devices Using Dna, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An article of manufacture including an organic structure and inorganic atoms bonded to specific locations on the organic structure.

Acuta Enews December 2003, Vol 32, No 12

ACUTA Newsletters

In This Issue

From the President........................ Walter L. Czerniak, Northern Illinois Univ.

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

Eleanor Smith, ACUTA Business Manager, Retires

Meet ACUTAs New Business Manager, Margaret Riley

Wireless lndustry Announces Recycling lnitiative...................... CTIA

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

ACUTA Member Sites to See

Thanks to Sponsors for '03

ACUTA: Have You Shopped the eStore Lately?

Welcome New Members

Deceleration Lanes Of Left-Turn Bays Of Four-Lane Expressways, Karen Schurr, Patrick T. Mccoy, Geza Pesti, Anthonny Egelhoff, Rebecca Burdick

Nebraska Department of Transportation: Research Reports

No abstract provided.

Implementation Of The Superstructure/Substructure Joint Details, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Spliced I-Grinder Concrete Bridge System, Maher K. Tadros, Charles J. Vranek

Nebraska Department of Transportation: Research Reports

No abstract provided.

Experimental Evaluation Of Constraint Automata Solutions To The Genome Map Assembly Problem, Viswanathan Ramanathan

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

DNA sequences are really huge having a length of around 3-4 million base pairs. Hence, each DNA sequence has to be cut down into small fragments using restriction enzymes. Once analyzed, these fragments have to be arranged or assembled into a single set of sequences called a genome map, to obtain the original DNA sequence. This problem is called the Genome Map Assembly Problem. A Constraint-Automata Solution was proposed for this purpose [11]. This thesis improves and implements the Constraint-Automata Solution to find all the possible solutions. The Modified Constraint-Automata Solution was implemented in Perl and executed on parts of …

Constraint Datalog In Trust Management, Scot Anderson

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

Constraint Datalog holds an increasing role in Trust Management. We discuss several Trust Management systems and give a description of the environment and requirements for Trust Management. Constraint Datalog using addition constraints and approximation theory provides an expressive semantic with which to describe security policies for credentials, delegations and authorizations. Approximation theory allows halting in Constraint Datalog over addition constraints. We use the decision problem of Diophantine equations to show that Constraint Datalog over addition constraints is complete. Combining these two concepts provides an approximately complete, safe language. The problem of constant additions to closed languages provides reasons for using …

Thermodynamic Determination Of The Cation Distribution In Nixmn1-Γ-Xfe2+Γo4 Ferrites, Qiangmin Wei, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

The cation distribution in the spinel ferrite system NixMn1-γ-xFe2+γO4 (x = 0, 0.25, 0.5, 0.75 and γ = 0.137) has been calculated analytically in complete form as a function of thermodynamic parameters. A generalized theoretical framework based on the O’Neill–Navrotsky model and Newton methods was used to solve a multicomponent system for up to 10 cation species. The relationship between the cation distribution and composition is given. The results are shown to agree with the available experimental results.

Solid-Like Dynamics In Ultrathin Films Of Polymeric Liquids, Gaurav Singh, Ravi F. Saraf, Yves Martin

Gaurav Singh Publications

In this letter, we demonstrate that, at mesoscales, nonferroelectric liquid films of poly~dimethyl siloxane! exhibit significant electrostriction not present in the corresponding bulk state. Remarkably, the observed electrostrictive effect has a response time ,20 ms in contrast to .5 ms recorded in conventional bulk ~ferroelectric! polymers. The emergence of this fast electrostrictive strain in thin films is explained in terms of the amalgamation of two contrasting dynamic features—the influence of a highly mobile, viscous layer ~at the air/film interface! on the less-mobile, but fast responding, solid-like layer at the film/substrate interface. The effect is observed for thickness below 200 nm.

Screw Dislocation Interacting With Twin Interfacial Edge Cracks Between Two Bonded Dissimilar Piezoelectric Strips, Xiangfa Wu, Yuris A. Dzenis, Tian-You Fan

Department of Engineering Mechanics: Faculty Publications

This paper is concerned with the electroelastic potentials and the fracture parameters of a twin-edge-cracked piezoelectric bimaterial strip with a screw dislocation. By means of conformal mapping technique and the known dislocation solution, the antiplane displacement and inplane electric potentials are obtained in closed-form. The intensity factors and the energy release rate are extracted explicitly. In some limiting cases, the present solutions cover those in the literature.

Acuta Enews November 2003, Vol 32, No. 11

ACUTA Newsletters

In This Issue

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

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

No Spam for Me, Please

VolP Design Recommendations................................. John Garrison, Alcate

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

Thanks to Exhibitors for '03

ACUTA Board Report................................... Carmine Piscopo, Providence College

Welcome New Members

ACUTA: Have You Shopped the eStore Lately?

A Macrokinetic Study Of The High-Temperature Solid-Phase Titanium-Carbon Reaction, Julia Y. Kostagorva, Hendrik J. Viljoen, Alexander S. Shteinberg

Papers in Reaction Kinetics

An experimental method, electro thermal explosion (ETE), is used to measure the macro kinetic parameters of the high-temperature titanium/carbon reaction. Different stages of the reaction have been identified, but the focus of this study is on the reaction between solid titanium and solid carbon, i.e., prior to the melting of titanium. The reaction has high activation energy, and an electric current is used to heat the cylindrically shaped sample to a specified temperature. The current is shut off at a temperature below the melting point of titanium; any further temperature rise is only due to reaction. The output of the …

Steel Bridge System With Delayed Composite Action, Atorod Azizinamini, Aaron Jon Yakel

Nebraska Department of Transportation: Research Reports

No abstract provided.

Spin Blockade In Ferromagnetic Nanocontacts, M. Ye Zhuralev, Evgeny Y. Tsymbal, Sitaram Jaswal, A.V. Vedyayev, B. Dieny

Materials Research Science and Engineering Center: Faculty Publications

Using a free-electron model and a linear response theory we investigate spin-dependent electronic transport in magnetic nanocontacts in the ballistic regime of conduction. We emphasize the fact that in atomic-size ferromagnetic contacts it is possible to achieve the conductance value of e²/h, which implies a fully spin-polarized electric current. We explore some consequences of this phenomenon. In particular, we show that the presence of a nonmagnetic region in the nanocontact separating two ferromagnetic electrodes can lead to a spin blockade resulting in very large values of magnetoresistance.

Surface Structure Of Ultrathin Copolymer Films Of Ferroelectric Vinylidene Fluoride (70%) With Trifluoroethylene (30%) On Graphite, Lei Cai, Hongwei Qu, Chenxi Lu, Stephen Ducharme, Peter A. Dowben, Jiandi Zhang

Materials Research Science and Engineering Center: Faculty Publications

The structure and local structural distortions, through the polarization manipulation, of crystalline films of ferroelectric vinylidene fluoride (70%) with trifluoroethylene (30%) [P(VDF-TrFE)] copolymer on graphite were studied by scanning tunneling microscopy (STM). A quasispiral twist in C[Single Bond]C bonds with rotations about the polymer chain axis was observed by high-resolution STM, indicating a surface relaxation of the strained copolymer films. Such a relaxation behavior appears to be linked to the observed local dipole rotations accompanied by the reversal of the local polarization with biasing the STM tip. A structure model is proposed based upon the observations.

Oct 2003, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Farmall Donation Storage Space Funding Opportunities

Deterministic Solutions For A Step-Growth Polymerization, Sungjae Choi, Xiangdong Liu, Delmar C. Timm

Papers in Molecular Chemistry

Chain topology, including branch node, chain link and cross-link dynamics that contribute to the number of elastically active strands and junctions, are calculated using purely deterministic derivations. Solutions are not coupled to population density distributions. An eigenzeit transformation assists in the conversion of expressions derived by chemical reaction principles from time to conversion space, yielding transport phenomena type expressions where the rate of change in the molar concentrations of branch nodes with respect to conversion is expressed as functions of the fraction of reactive sites on precursors and reactants. Analogies are hypothesized to exist in cross-linking space that effectively distribute …

Vector Dissipativity Theory For Discrete-Time Large-Scale Nonlinear Dynamical Systems, Wassim M. Haddad, Qing Hui, Vijaysekhar Chellaboina, Sergey Nersesov

Department of Electrical and Computer Engineering: Faculty Publications

In analyzing large-scale systems, it is often desirable to treat the overall system as a collection of interconnected subsystems. Solution properties of the large-scale system are then deduced from the solution properties of the individual subsystems and the nature of the system interconnections. In this paper, we develop an analysis framework for discrete-time large-scale dynamical systems based on vector dissipativity notions. Specifically, using vector storage functions and vector supply rates, dissipativity properties of the discrete-time composite large-scale system are shown to be determined from the dissipativity properties of the subsystems and their interconnections. In particular, extended Kalman-Yakubovich-Popov conditions, in terms …

Synthesis Of Chemical Tags, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A method for forming a biological chemical tag. At least one double stranded DNA molecule is provided. At least a portion of the at least one double stranded DNA molecule is denatured. At least one chemical moiety that prohibits recrystallization of the at least one denatured portion to which the at least one chemical moiety is attached is attached to at least one nucleotide in the at least one denatured portion of the at least one double stranded DNA molecule.

Development Of Standard Methods To Estimate Manure Production And Nutrient Characteristics From Dairy Cattle, T. Nennich, J. H. Harrison, D. Meyer, W. P. Weiss, A. J. Heinrichs, R. L. Kincaid, W. J. Powers, Richard K. Koelsch, P. E. Wright

Department of Biological Systems Engineering: Conference Presentations and White Papers

Total collection data from many universities were pooled for statistical analyses to evaluate existing data from dairy animals and determine if one or more modifications were needed for Standard Table D384.1. Many of these studies were carried out to evaluate nutritional characteristics associated with different diets. The data collected were sufficient to evaluate total manure, total and volatile solids, and N excretion values. Some experiments had sufficient number of samples analyzed to evaluate P, K, Ca, Mg, Na, Cl, S, and micro-elements. Statistical analyses were conducted to determine if a single column value was appropriate and define the regression equations …

Proposed Beef Cattle Manure Excretion And Characteristics Standard For Asae, Galen E. Erickson, B. Auvermann, R. A. Eigenberg, L. W. Greene, Terry J. Klopfenstein, Richard K. Koelsch

Department of Biological Systems Engineering: Conference Presentations and White Papers

A committee was formed consisting of both animal scientists and agricultural engineers to evaluate and update current ASAE standards. An intake minus retention model was developed to estimate nutrient excretion. This approach allows users (producers, engineers, etc.) to develop site specific information based on known variables such as protein or phosphorus content of diets and cattle performance. This approach illustrates the importance of nutrition on nutrient excretion in livestock operations. Our focus is for feedlot cattle and updates excretion of dry matter (DM or total solids), organic matter (OM or volatile solids), N, P, Ca, K, Na, Mg, S, Cu, …

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

Department of Biological Systems Engineering: Conference Presentations and White Papers

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 …

Nebraska Blueprint – Fall 2003

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

The Big Room Where They Smash Stuff – A closer look at the Structures Lab

Interactive Innovation – Students and professionals create interactive engineering exhibit

Making Their Way: Women Find Their Place in Engineering

More Than Meets the Eye – Getting to know Dr. Jennifer Brand

What We Wish We Had Known – At the close of their first semester, freshmen look back

Taking Out the Garbage in Style – Computer Engineering students embark on new research

A Conversation with Jeremy Befort – Student reaches out to others

Book Review: Skunk Works: A Personal …