Engineering Commons^™

Dec 2004, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Introductions Treasurer's Report Curator's Report

Imaging Using Lateral Bending Modes Of Atomic Force Microscope Cantilevers, A. Caron, U. Rabe, M. Reinstadtler, Joseph A. Turner, W. Arnold

Nebraska Center for Materials and Nanoscience: Faculty Publications

Using scanning probe techniques, surface properties such as shear stiffness and friction can be measured with a resolution in the nanometer range. The torsional deflection or buckling of atomic force microscope cantilevers has previously been used in order to measure the lateral forces acting on the tip. This letter shows that the flexural vibration modes of cantilevers oscillating in their width direction parallel to the sample surface can also be used for imaging. These lateral cantilever modes exhibit vertical deflection amplitudes if the cantilever is asymmetric in thickness direction, e.g., by a trapezoidal cross section.

Conversation Exchange Dynamics: A New Signal Primitive For Computer Network Intrusion Detection, John C. Mceachen, John M. Zachary, Junling Wang, Kah Wai Cheng

U.S. Navy Research

As distributed network intrusion detection systems expand to integrate hundreds and possibly thousands of sensors, managing and presenting the associated sensor data becomes an increasingly complex task. Methods of intelligent data reduction are needed to make sense of the wide dimensional variations. We present a new signal primitive we call conversation exchange dynamics (CED) that accentuates anomalies in traffic flow. This signal provides an aggregated primitive that may be used by intrusion detection systems to base detection strategies upon. Indications of the signal in a variety of simulated and actual anomalous network traffic from distributed sensor collections are presented. Specifically, …

Oscillatory Interlayer Exchange Coupling In [Pt/Co]N/Nio/[Co/Pt]N Multilayers With Perpendicular Anisotropy: Dependence On Nio And Pt Layer Thicknesses, Z. Y. Liu, Lanping Yue, D. J. Keavney, Shireen Adenwalla

Materials Research Science and Engineering Center: Faculty Publications

Interlayer exchange coupling has been studied in a series of [Pt( t_Pt Å)/Co(4 Å)]n/NiO( t_NiO)/[Co(4 Å)/Pt( t_Pt Å)]_n multilayers with perpendicular anisotropy. The coupling oscillates between antiferromagnetic and ferromagnetic as a function of t_NiO with a period of ~5 Å, and the oscillatory behavior is related to the antiferromagnetic ordering of the NiO layer. This interlayer coupling between two Co/Pt multilayers is shown to occur domain by domain by magnetic force microscopy imaging. For the strongest antiferromagnetic coupling at t_NiO = 11 Å, an oscillation with a period of ~6 Å is superposed …

Ranque–Hilsch Vortex Tube Thermocycler For Fast Dna Amplification And Real-Time Optical Detection, Ryan J. Ebmeier, Scott E. Whitney, Amitabha Sarkar, Michael Nelson, Nisha Padhye, George Gogos, Hendrik J. Viljoen

Papers in Biochemical Engineering

An innovative polymerase chain reaction (PCR) thermocycler capable of performing real-time optical detection is described below. This device utilizes the Ranque–Hilsch vortex tube in a system to efficiently and rapidly cycle three 20 mL samples between the denaturation, annealing, and elon-gation temperatures. The reaction progress is displayed real-time by measuring the size of a fluo-rescent signal emitted by SYBR green/double-stranded DNA complexes. This device can produce significant reaction yields with very small amounts of initial DNA, for example, it can amplify 0.25 fg (,5 copies) of a 96 bp bacteriophage l-DNA fragment 2.731011-fold by performing 45 cycles in less than …

Quantum Entanglement Of Anisotropic Magnetic Nanodots, Ralph Skomski, Andrei Y. Istomin, Anthony F. Starace, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

Anisotropic magnetic nanodots are promising physical realizations of qubits for quantum computing at finite temperature owing to their well-separated low-lying energy levels and scalability. The entanglement of two interacting magnetic nanodots is investigated and shown both analytically and numerically to be resonantly dependent on their interaction strength and on differences in their properties. These results provide criteria for fabricating and coupling magnetic nanodots so that their low-lying eigenstates can be significantly entangled.

Attenuation Of Ultrasonic Waves In Rolled Metals, Liyong Yang, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave propagation and scattering model is formulated by the Dyson equation using an anisotropic Green’s function approach.Within the limits of the first-order smoothing approximation, the Dyson equation is solved in the spatial Fourier transform domain. The results presented are shown to be directional dependent, …

A Template-Based Conceptual Modeling Infrastructure For Simulation Of Physical Security Systems, Ashu Guru, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Although simulation is one of the most innovative and cost-effective tools for modeling and analyzing a system, simulation studies often fail to provide any useful results. One reason is attributed to the fact that model formulation depends on the skills of the analyst. This paper describes a research to develop a conceptual modeling infrastructure to assist a simulation analyst in specifying components for studying physical security systems. The modeling framework has been programmed as an internet-based web application. Using the application, the successful development and implementation of a physical security simulation model will be aided by a defined scientific methodology …

Acuta Enews December 2004, Vol. 33, No. 12

ACUTA Newsletters

ln This lssue

From the President............................. Tamara J . Closs, ACUTA President, Georgetown University

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

Cell-Phone Directory to Be Published?

Web Tip: lnfo about and from ACUTA Events........................ Aaron Fuehrer, ACUTA Computer Svcs. Mgr.

Member Sites to See 5 Board Report.................. Cormine Piscopo, Providence College

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

Welcome New Members

Extending Asterism Decoding To Qam And Its Complexity In Rician Fading Mimo Systems, Phillip Conder, Tadeusz A. Wysocki

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

The area of Multiple Input Multiple Output (MIMO) communications systems has received enormous attention recently as they can provide a roughly linear increase in data rate by using Multiple Transmit and Receive antennas. The optimal detection strategy for a MIMO receiver is to perform a Maximum-Likelihood (ML) search over all possible transmitted symbol combinations has an exponential complexity when the constellation size of number of transmit antennas increase. A number of sub-optimal decoders, such as VBLAST, provide linear decoding only where the number of receive antennas is at least equal to the number of transmit antennas.

Certain Asterism decoding described …

A Study Of Umts Turbo Codes Across Space Time Spreading Channel With The Case Of M = 1 And M = 2, Ibrahim S. Raad, Peter Vial, Tadeusz A. Wysocki

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

The study presented in this paper is that of Universal Mobile Telecommunications Systems (UMTS) Turbo Codes across Space Time Spreading channel with one transmitter antenna, one receiver (m = 1) and two transmitter antennas and one receiver (m = 2) to see to what extent the bit error rate (BER) can be improved. Using the Max-log decoding algorithm and 12 iterations it is shown in the simulation results that an extra 5 dB is achievable.

Load-Balanced Route Discovery For Mobile Ad Hoc Networks, Mehran Abolhasan, Justin Lipman, Tadeusz A. Wysocki

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

This paper presents Flow-Aware Routing Protocol (FARP), a new routing strategy designed to improve load balancing and scalability in mobile ad hoc networks. FARP is a hop-by-hop routing protocol, which introduces a flow-aware route discovery strategy to reduce the number of control overheads propagating through the network and distributes the flow of data through least congested nodes to balance the network traffic. FARP was implemented in Glomosim and compared with AODV. To investigate the load distribution capability of FARP new performance metrics were introduced to measure the data packet flow distribution capability of the each routing protocol. The simulation results …

Thermodynamic Analysis Of Separation Systems, Yaşar Demirel

Papers in Thermal Mechanics

Separation systems mainly involve interfacial mass and heat transfer as well as mixing. Distillation is a major separation system by means of heat supplied from a higher temperature level at the reboiler and rejected in the condenser at a lower temperature level. Therefore, it resembles a heat engine producing a separation work with a rather low efficiency. Lost work (energy) in separation systems is due to irreversible processes of heat, mass transfer, and mixing, and is directly related to entropy production according to the Gouy-Stodola principle. In many separation systems of absorption, desorption, extraction, and membrane separation, the major irreversibility …

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Ethylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-T, Jayanta Sinha, Bradley A. Plantz, Mehmet Inan, Michael Meagher

Papers in Biotechnology

It was observed that during fermentative production of recombinant ovine interferon-H (r-oIFN-H ) in Pichia pastoris, a secreted recombinant protein, the protein was degraded increasingly after 48 h of induction and the rate of degradation increased towards the end of fermentation at 72 h, when the fermentation was stopped. Proteases, whose primary source was the vacuoles, was found in in-creasing levels in the cytoplasm and in the fermentation broth after 48 h of induction and reached maximal values when the batch was completed at 72 h. Protease levels at various cell fractions as well as in the culture supernatant were …

A Plan For Router Testing In Network-On-Chip, Zachariah Thomas Link

Open Access Master's Theses (through 2010)

This thesis presented a new method for testing routers and cores on Network-On-Chip (NoC) systems.It proposed a new algorithm for router testing that relies heavily on the reuse of the network infrastructure within an NoC. Possible wrapper architecture for the router was also presented. Combing the router and core wrapper into one wrapper can reduce the wrapper hardware and is important in the reuse of the network for router testing. Finally, an integrated algorithm for scheduling tests for routers and cores was presented. Simulations were run comparing results using this integrated algorithm to previous work based on boundary scan.

Advisor: …

Efficient Algorithm For Computing Einstein Integrals, Junke Guo, Pierre Y. Julien

Department of Civil and Environmental Engineering: Faculty Publications

Analytical approximations to Einstein integrals are proposed. The approximations represented by two fast-converging series are valid for all values of their arguments. Accordingly, the algorithm can be easily incorporated into professional software like HEC-RAS or HEC-6 with minimum computational effort.

Algoritmo Genético Para Calibração Automática De Um Simulador De Tráfego Em Rodovias De Pista Simples, C. Y. Egami, J. R. Setti, Laurence Rilett

Department of Civil and Environmental Engineering: Faculty Publications

Este trabalho relata o desenvolvimento de um sistema automático para calibração do modelo de simulação de tráfego em rodovias de pista simples TRARR, baseado em um algoritmo genético. O processo de calibração consiste em procurar valores para alguns parâmetros selecionados do simulador, de tal modo que a diferença entre as correntes de tráfego simuladas e as observadas em campo sejam minimizadas. Os parâmetros escolhidos para a calibração estão relacionados principalmente ao comportamento dos motoristas e, por isso, de difícil calibração. As diferenças entre a simulação e o fluxo real foram determinadas em termos de duas medidas de desempenho: a velocidade …

Synthesis And Characterization Of Starch Acetates With High Substitution, Yixiang Xu, Vesselin Miladinov, Milford A. Hanna

Industrial Agricultural Products Center: Publications and Information

Acetylation of high-amylose (70%) maize starch to high degree of substitution (DS) was studied by reacting starch with acetic anhydride using 50% aqueous NaOH as the catalyst. DS increased with increasing reaction times and increasing ratios of acetic anhydride to starch. Reaction efficiency (RE) increased with longer reaction times and decreased with increases in the ratios of acetic anhydride to starch for extended reaction times. Increasing the amount of NaOH increased both DS and RE. A series of starch acetates with DS values of 0.57-2.23 were prepared and their crystalline structures, chemical structures, thermal stability, and morphological properties were investigated. …

Safety Evaluation Of Left Turn Lane Line Width At Intersections With Opposing Left Turn Lanes, Aemal Khattak, Bhaven Naik, Vijay Kannan

Nebraska Department of Transportation: Research Reports

The objective of this research project was to evaluate the effectiveness of offset opposing left-turn lanes at signalized intersections in reducing the frequency and severity of left-turn related accidents. The Cities of Lincoln and Omaha offset opposing left-turns by widening leftturn lane lines in June 1999 at six intersections. The research team investigated traffic accident patterns between January 1994 and December 2002 at those six intersections by making comparisons with two control intersections (i.e. intersections at which left-turns were not offset by lane line widening) using a four-step research methodology. First, existing literature was reviewed to determine the extent and …

Bond Strength Of Self-Consolidating Concrete For Prestressed Concrete Applications, Christopher Y. Tuan, Amgad F. Girgis

Nebraska Department of Transportation: Research Reports

No abstract provided.

Thermodynamic Modeling, Energy Equipartition, And Nonconservation Of Entropy For Discrete-Time Dynamical Systems, Wassim H. Haddad, Qing Hui, Sergey G. Nersesov, Vijaysekhar Chellaboina

Department of Electrical and Computer Engineering: Faculty Publications

We develop thermodynamic models for discrete-time large-scale dynamical systems. Specifically, using compartmental dynamical system theory, we develop energy flowmodels possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical systems. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical system to do useful work and grow more organized, and show that conservation of energy in an isolated thermodynamic system necessarily leads to nonconservation of ectropy and entropy. In addition, using the system ectropy as a Lyapunov function candidate, we show that our discrete-time, …

Annealing And Oxidation Of Silicon Oxide Films Prepared By Plasma-Enhanced Chemical Vapor Deposition, X. Y. Chen, Yongfeng Lu, L. J. Tang, Y. H. Wu, B. J. Cho, J. R. Dong, W. D. Song

Department of Electrical and Computer Engineering: Faculty Publications

We have investigated phase separation, silicon nanocrystal (Si NC) formation and optical properties of Si oxide (SiO_x, 0,x,2) films by high-vacuum annealing and dry oxidation. The SiO_x films were deposited by plasma-enhanced chemical vapor deposition at different nitrous–oxide/silane flow ratios. The physical and optical properties of the SiO_x films were studied as a result of high-vacuum annealing and thermal oxidation. X-ray photoelectron spectroscopy (XPS) reveals that the as-deposited films have a random-bonding or continuous-random-network structure with different oxidation states. After annealing at temperatures above 1000 °C, the intermediate Si continuum in XPS spectra (referring to the …

Stable Zeolite/Cellulose Composite Materials And Method Of Preparation, Gustavo F. Larsen

Department of Chemical and Biomolecular Engineering: Patents

Stable cellulosic fiber material for use in forming zeolite/cellulose composites is prepared by suspending loose cellulose fibers in an aqueous solution of sodium hydroxide, potassium hydroxide or sodium silicate, stirring the resulting suspension until it reaches a macroscopically homogenous appearance, heating the resulting mixture at a temperature of 323-423 K until only dry solids remain, contacting the resulting mixture with excess distilled water to remove physically adsorbed or trapped sodium hydroxide, potassium hydroxide or sodium silicate from the fibers, and heating the resulting fiber material at 323-423 K to dry the fiber material. Stable zeolite/cellulose composite material characterized in that …

Disorder-Induced Depression Of The Curie Temperature In Mechanically Milled Gdal2, Marco Morales Torres, D. S. Williams, Paul M. Shand, C. Stark, Thomas M. Pekarek, Lanping Yue, Valeri G. Petkov, Diandra Leslie-Pelecky

Materials Research Science and Engineering Center: Faculty Publications

The effect of disorder on the ferromagnetic transition is investigated in mechanically milled GdAl₂. GdAl₂is a ferromagnet when crystalline and a spin glass when amorphous. Mechanical milling progressively disorders the alloy, allowing observation of the change from ferromagnetic to a disordered magnetic state. X-ray diffraction and pair-distribution-function analysis are used to determine the grain size, lattice parameter, and mean-squared atomic displacements. The magnetization as a function of temperature is described by a Gaussian distribution of Curie temperatures. The mean Curie temperature decreases with decreasing lattice parameter, where lattice parameter serves as a measure of defect concentration. …

Parametric Investigation Of Laser Nanoimprinting Of Hemispherical Cavity Arrays, L. P. Li, Yongfeng Lu, D. W. Doerr, Dennis R. Alexander, X. Y. Chen

Department of Electrical and Computer Engineering: Faculty Publications

A monolayer of self-assembled silica particles can be imprinted into a silicon substrate by laser irradiation (KrF excimer laser, λ=248 nm). Periodical hemispherical cavities can be therefore created on the substrate surface. The influences of various particle sizes and laser fluence were investigated. In addition, preheating of the substrate significantly improves the performance. One-dimensional thermal calculation was employed to understand the thermal effect in this process. Three-dimensional optical simulation provided an accurate insight into the light intensity enhancement. Raman spectroscopy was used to examine the stress induced by the laser imprinting process resided in the cavity structures.

Edge-Cracked Orthotropic Bimaterial Butt Joint Under Antiplane Singularity, Xiangfa Wu, Yuris A. Dzenis, Emrah Gokdag

Department of Engineering Mechanics: Faculty Publications

Explicit elastic solutions are given for an edge-cracked orthotropic bimaterial butt joint under antiplane singularity of a screw dislocation and a line-force. During the procedure, conformal mapping and known dislocation solution are utilized for constructing the fundamental solution to the present problem. Stress intensity factor (SIF) and energy release rate (ERR) of the edge-cracked butt joint are given in closed-form. In limiting cases, results provided in this work cover those in literature.

Screw Dislocation Interacting With Interfacial Edge-Cracks In Piezoelectric Bimaterial Strips, Xiangfa Wu, Yuris A. Dzenis, Bradley D. Rinschen

Department of Engineering Mechanics: Faculty Publications

This paper is concerned with the interaction between an interfacial edge-crack and a screw dislocation under out-of-plane mechanical and in-plane electric loading in a piezoelectric bimaterial strip. In addition to a discontinuous electric potential across the slip plane, the dislocation is subjected to a line-force and a line-charge at the core. Under the framework of linear piezoelectricity, the out-of-plane displacement and in-plane electric potentials are constructed in closed-form by means of conformal mapping technique and the known solution for screw dislocation in cracked piezoelectric bimaterial. The intensity factors (IFs) and energy release rate (ERR) are derived explicitly.

Acuta Enews November 2004, Vol. 33, No. 11

ACUTA Newsletters

ln This Issue

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

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

Overheard on the Listserv: Revising Work-Flow Processes

Web Tip: Products and Services Search Available .... Aaron Fuehrer, ACUTA Computer Svcs. Mgr.

Providing Network and Voice Services to Remote Locations....................... Dave Barta, Univ. of Oregon

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

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

Welcome New Members

Exergy Use In Bioenergetics, Yaşar Demirel

Papers in Analytical Chemistry

Every developed and adapted biological system extracts useful energy from outside, converts, stores it, and uses for muscular contraction, substrate transport, protein synthesis, and other energy utilizing processes. This energy management in a living cell is called the bioenergetics, and the useful energy is the exergy, which is destroyed in every irreversible process because of the entropy production. The converted exergy is the adenosine triphosphate (ATP) produced through the oxidative phosphorylation coupled to respiration in which the exergy originates from oxidation of reducing equivalents of nutrients. A living cell uses the ATP for all the energy demanding activities; it has …

Oct 2004, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Old Trusty Show New Paint Scheme History of Ag Engineering Department