Engineering Commons^™

Final Environmental Assessment For Endangered Species Habitat Enhancement/Creation Along Tile Missouri River Main Stem System

United States Army Corps of Engineers, Omaha District

The interior least tern (Sterna antillarum) and the piping plover (Charadrius melodus) are federally endangered and threatened species, respectively, which nest on sandbars in the Missouri River. This nesting habitat has been decreasing in past years, at least in part due to vegetative encroachment. Vegetation is no longer regularly scoured from sandbars by heavy spring flows and/or ice, primarily because flows are regulated by the main stem dams. New sandbar creation is uncommon because the river carries less sediment and is no longer meandering along much of its course. Bank erosion still continues to supply sediment …

Kinetic Analysis Of Competing Intramolecular And Intermolecular Polymerization Reactions, Hossein Noureddini, Delmar C. Timm

Papers in Molecular Chemistry

ABSTRACT: Kinetic reaction theory was used to model a step-growth, thermoset polymerization of a monomer of even functionality/. Intermolecular additions were represented by second-order and intramolecular reactions were expressed by first-order rate expressions. All functional groups were assumed to react with equal reactivity. Independent variables are degree of polymerization i, extent of cross-linking j, and conversion p. The normalized rate constant for intramolecular reactions is c. The solution for the normalized population density distribution............ subj Formulae for the number-, mass-, and cross-link-average molecular weights were derived.

Effect Of Strain Rate On Material Properties Of Sheet Steels, M. Kassar, Wei-Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The effect of strain rate on tensile and compressive mechanical properties of sheet steels is investigated experimentally and analytically. Three sheet steels are studied in both longitudinal and transverse directions under different strain rates and different amounts of prior cold stretching in order to determine the separate effects of strain rate and aging half of the cold-stretched coupons are tested in an average of two days after cold-stretching operation. The remaining half are tested to failure at least 30 days after cold-stretching operation The results show that the proportional limit yield strength and ultimate strength increase with increasing strain rate …

Effect Of Strain Rate On Cold-Formed Steel Stub Columns, M. Kassar, C. L. Pan, Wei-Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The material properties of steel and the strength of steel members are affected by strain rate to investigate this characteristic for compression members 49 stub columns fabricated from 35XF sheet steel and 48 stub columns fabricated from 50XF sheet steel are studied experimentally and analytically under different strain rates The strain rate ranged from 10^-5 to 0.1. in./in./sec (10^-5 to 0.1 mm/mm/s). The material properties of 35XF and 50XF sheet steels developed from previous tests are used for the evaluation of the test data obtained from the member tests using specimens fabricated from the same sheet steel. The …

Estimating Uplift Capacity Of Light Steel Roof System, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Effect Of Temperature On The Ultimate Strength And Modulus Of Whisker‐Reinforced Ceramics, Douglas R. Carroll, Lokeswarappa R. Dharani

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Whiskers are a very attractive means of reinforcing a ceramic material. It has been shown that the whiskers dramatically improve the ultimate strength and modulus of the materials at room temperature. However, recent studies indicate that at high temperatures the improvement is less pronounced, or there is no improvement at all. In this paper a model is developed to explain why the properties are degraded at high temperature. The parameters which seem most important for high‐temperature performance are the coefficients of thermal expansion and Poisson's ratios for the constituents, the heat treatment temperature, and the coefficient of friction between the …

Machining Of Composite Materials. Part Ii: Non-Traditional Methods, Serge Abrate, D. Walton

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Machining of composite materials is difficult due to the heterogeneity and heat sensitivity of the material and the high abrasiveness of the reinforcing fibers. This results in damage being introduced into the workpiece and very high tool wear. The use of traditional machining methods was reviewed in Part I of this paper. Here new methods are considered: laser, waterjet, electro-discharge, electro-chemical spark, and ultrasonic machining. These various techniques have been applied to organic matrix composites with aramid, glass, graphite fiber reinforcement but also to metal matrix and ceramic matrix composites. © 1992.

Optimizing The Integration Of Photovoltaic Systems With Electric Utilities, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The author introduces a comprehensive simulation package whereby the optimal size, operation, performance and economics of a photovoltaic (PV) system can be determined in the utility-integrated mode. The central issue is to present a single definitive optimization model. A stepwise analytical methodology starting at the solar resource and culminating in the value of the PV system in terms of avoided costs is provided. The methodology includes processing of the solar irradiance; identification of the PV system''s configuration and operational features; identification of real-time system controls in the presence of PV generation; security assessment in the presence of PV and production …

Pavement Deflection Evaluations, R. Clark Graves, David L. Allen

Kentucky Transportation Center Research Report

In this study a procedure has been developed to evaluate the structural condition of pavements using Road Rater deflection measurements. These procedures compare actual field deflections with deflections calculated by the Chevron N-Layer linear elastic computer program. The results obtained from these procedures are the layer moduli of the pavement materials. Procedures have been developed for asphaltic concrete pavements and composite pavements, including broken and non-broken concrete layers. This report also contains a comparison of structural overlay determined using the results of the new procedure, with overlays calculated using results from the 2-3 Projected procedure currently used by the Pavement …

Roadway Related Tort Liability And Risk Management: 2nd Edition, Daniel S. Turner, Kenneth R. Agent

Kentucky Transportation Center Research Report

This training material has been prepared to address the tort liability problems faced by the Kentucky Transportation Cabinet and Kentucky local governments. The workbook defines the problem by reviewing the national picture of growing numbers of suits and escalating financial losses from suits against highway agencies.

The workbook also sets out solutions, and reviews actions which can decrease the exposure of highway agencies to these suits. This risk management concept is emphasized throughout the workbook.

Topics In Nonlinear Stochastic Control, Estimation, And Decision, Using A Measure Transformation Approach, Charalambos Demetriou Charalambous

Electrical & Computer Engineering Theses & Dissertations

We discuss topics in the theory of nonlinear stochastic control, estimation, and decision via a probabilistic approach using measure transformations and martingale theory. First, we investigate the problem of estimating a diffusion process using coordinate transformations and measure transformations, both locally and globally; this is the analog of nonlinear coordinate and state feedback transformations used to obtain exact linearization in nonlinear deterministic control problems. Our results are new in that we use a probabilistic approach rather than a purely geometric one, and also in that we derive representations when the processes are defined locally rather than just globally. A gauge …

A Complete Model Characterization Of Brushless Dc Motors, N. Hemati, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The authors address the modeling problem associated with brushless DC motors (BLDCMs) with nonuniform air gaps that operate in a range where magnetic saturation may exist. The mathematical model includes the effects of reluctance variations as well as magnetic saturation to guarantee proper modeling of the system. An experimental procedure is developed and implemented in a laboratory environment to identify the electromagnetic characteristics of a BLDCM in the presence of magnetic saturation. It is demonstrated that the modeling problem associated with the class of BLDCMs can be formulated in terms of mathematically modeling a set of multidimensional surfaces corresponding to …

Use Of Time Varying Dynamics In Neural Network To Solve Multi-Target Classification, S. N. Balakrishnan, J. Rainwater

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Several types of solutions exist for multiple target tracking. These techniques are computation-intensive and in some cases very difficult to operate online. The authors report on a backpropagation neural network which has been successfully used to identify multiple moving targets using kinematic data (time, range, range-rate and azimuth angle) from sensors to train the network. Preliminary results from simulated scenarios show that neural networks are capable of learning target identification for three targets during the time period used during training and a time period shortly after. This effective classification period can be extended by the use of networks in coordination …

Asce Lrfd Method For Stainless Steel Structures, Shin Hua Lin, Wei-Wen Yu, Theodore V. Galambos

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In recent years, probability-based load-and-resistance-factor-design (LRFD) method has been successfully applied to the design of hot-rolled steel sections and cold-formed steel members in the United States and foreign countries. In order to develop the LRFD criteria for the design of cold-formed stainless steel structural members and connections, a research project was conducted at the University of Missouri-Rolla since 1986 under the sponsorship of the American Society of Civil Engineers (ASCE). This newly developed LRFD Specification with Commentary has been adopted by ASCE as a new standard in 1990. It supersedes the 1974 edition of the Specification for the Design of …

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Triallylphosphine Plasma Polymerization And Reaction Of The Product With Volatile Transition Metal Compounds, S. D. Clymer, Nicholas C. Morosoff, A. L. Crumbliss

Chemical and Biochemical Engineering Faculty Research & Creative Works

The plasma polymerization of triallyl phosphine in order to form a crosslinked polymer thin film is described. The plasma polymer thin film has been characterized and shown to contain a high proporation of C=C and P groups conserved from the monomer. The accessibility of the phosphine groups has been demonstrated by reaction with O₂, NO, Ni(CO)₄, and Fe(CO)₅. Reaction with O₂, and NO results in a P=O moiety formation. Reaction with the gaseous metal carbonyls results in fixation of the metal via complexation by the P groups as a result of exchange …

Hierarchical Neurocontroller Architecture For Robotic Manipulation, Xavier J. R. Avula, Luis C. Rabelo

Chemical and Biochemical Engineering Faculty Research & Creative Works

A hierarchical neurocontroller architecture consisting of two artificial neural network systems for the manipulation of a robotic arm is presented. The higher-level network system participates in the delineation of the robot arm workspace and coordinates transformation and the motion decision-making process. The lower-level network provides the correct sequence of control actions. A straightforward example illustrates the architecture''s capabilities, including speed, adaptability, and computational efficiency

Composite Stock Cutting Through Simulated Annealing, Hanan Lutfiyya, Bruce M. Mcmillin, Pipatpong Poshyanonda, Cihan H. Dagli

Computer Science Faculty Research & Creative Works

This paper explores the use of Simulated Annealing as an optimization technique for the problem of Composite Material Stock Cutting. The shapes are not constrained to be convex polygons or even regular shapes. However, due to the composite nature of the material, the orientation of the shapes on the stock is restricted. For placements of various shapes, we show how to determine a cost function, annealing parameters and performance. © 1992.

Computer Networking For Operation Management And Optimization In Power Utility Industry, Ali K. Kamrani, Kamran K. Kamrani

Engineering Management and Systems Engineering Faculty Research & Creative Works

The connectivity, flexibility, and real time control capability of computer systems have led electric utility companies to consider the use of computers and telecommunication networks. The application of such an environment includes data acquisition, supervisory control, operation optimization, and data management. This paper presents the layout of a computer system network for an electric power utility.

A Methodology For Customer Requirements Generation In Communication Systems Planning, Negaa Albegami, Yildirim Omurtag

Engineering Management and Systems Engineering Faculty Research & Creative Works

In electronic communication systems it is nearly impossible to keep up with changing technology. This problem is further aggregated in the developing countries where the contractor (probably a western company) is expected to develop the system from the ground up. A basic problem which confronts this approach is either: 1) The customer will start adding or rejecting some of the capabilities, or 2) The local operation will never use some of the capabilities. Both of these outcomes are costly in terms of time and resources available to a developing country. This paper describes a new methodology for requirements generation to …

Educating Engineers To Manage Technology: An International Comparison, Daniel L. Babcock, Brian E. Lloyd

Engineering Management and Systems Engineering Faculty Research & Creative Works

Two countries, the United States and Australia, are compared in terms of: (1) the historical growth of their engineering professions; (2) the structure of their engineering professional organizations; (3) the prevalence of engineers in management positions; and (4 the education of their engineers for management responsibilities.

Application Of Total Quality Management To Research And Development: An Historical Perspective, Scott A. Dellana, Henry Allen Wiebe

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper discusses the historical applications of Total Quality Management (TQM) to Research and Development (R&D). Research aimed at establishing an effective model for the application of TQM philosophies and tools to the R&D environment must start from this historical perspective. The emphasis of this paper is on the relationship of quality tools and techniques to the application of TQM in R&D, providing the foundation for further model development. The scope and definition of R&D is presented and is followed by an overview of the TQM philosophy and its associated tools and techniques. Special attention is given to defining performance …

The Management Of Change: A Case Study, Stephen A. Raper, Richard Neal Callahan

Engineering Management and Systems Engineering Faculty Research & Creative Works

A literature review was conducted to identify some of the requirements for competitiveness and change that are being promoted by leaders in the manufacturing field. A survey was developed based on the literature review and was subsequently administered, via the case study method, at a midwestern US agricultural chemicals firm to determine the company's degree of compliance with the literature''s recommendations. To a large degree, the company complied with the requirements.

Development Of An Automated Ultrasonic Inspection Cell For Detecting Subsurface Discontinuities In Cast Iron, John Scott Burningham

Dissertations and Theses @ UNI

Manufacturing of value added products by companies in todays global marketplace requires the vendors to meet certain minimum standards, SAE, ASTM, ISO, etc. In a global economy, as a manufacturer for the year 2000 and beyond, preferred vendors will become ISO 9000 certified to maintain a market share of produced goods.

An automated inspection cell was developed for the inspection of cast iron ports to detect subsurface discontinuities. The cell consists of an ultrasonic flaw detector (UFD), transducer, robot, immersion tank, computer, and software. Normal beam pulse-echo ultrasonic nondestructive testing is performed on each rough casting.

Using test blocks and …

Transition From Laminar To Turbulent Flow Around An Airfoil, Chang-Ren Chen

Doctoral Dissertations

"A computational fluid dynamics (CFD) code has been developed for two-dimensional incompressible turbulent flows and employed to solve the Navier Stokes equations around an airfoil of arbitrary shape. A low-Reynolds-number k — e turbulence model including curvature effect was used to consider the gain and loss of turbulent kinetic energy. To include laminar sublayer into the computational domain, a multi-layer grid and a cubic-slpine grid were introduced through a conservative form of coordinate transformation. The flow structure varies with the Reynolds numbers. For an airfoil at low Reynolds numbers (below ten thousand), distinct vortex shedding patterns can be found in …

Explicit Multistage Schemes For The Solution Of The Three-Dimensional Compressible Euler/Navier-Stokes Equations, Alaa Ahmed Elmiligui

Mechanical & Aerospace Engineering Theses & Dissertations

The objective of this study was to develop a high-resolution-explicit-multi-block numerical algorithm, suitable for efficient computation of the three-dimensional, time-dependent Euler and Navier-Stokes equations. The resulting algorithm has employed a finite volume approach, using MUSCL-type differencing to obtain state variables at cell interface. Variable interpolations were written in the $\kappa$-scheme formulation. Inviscid fluxes were calculated via Roe's flux-difference splitting, and van Leer's flux-vector splitting techniques, which are considered state of the art. The viscous terms were discretized using a second-order, central-difference operator.

Two classes of explicit time integration has been investigated for solving the compressible inviscid/viscous flow problems--two-stage predictor-corrector schemes, …

Efficient Simulation Of Multi-Carrier Digital Communication Systems In Nonlinear Channel Environments, K. W. Schneider, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

For systems that contain both frequency division multiplexing and bandpass nonlinearities, the high sampling rate that is necessary for accurate simulation contributes to the long runtimes. A partial sum of products (ParSOP) method is proposed to reduce the sampling rate of such systems. The ParSOP method allows the simulation sampling frequency to be reduced by only generating those intermodulation products that are centered in the bandwidth of the single observed modulated subcarrier. Simulation results, obtained by using the complex power series nonlinear model on a filtered binary phase shift keying system, showed that a reduction in the simulation runtime by …

Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators : Stability Criteria, Pitak Chenkosol

Dissertations and Theses

The stability criteria for single-mode standing-wave laser oscillators in the strongly homogeneously broadened limit are reported for the first time. Two types of stability criteria are presented. The first type, called type 1, corresponds to the minimum value of threshold parameter for which an infinitesimal perturbation away from steady state grows into an oscillatory solution. Another type of stability criteria, called type 2, corresponds to the minimum value of threshold parameter for which large amplitude oscillatory solutions do not decay to the steady state solution. Undamped pulsations in single mode strongly homogeneously broadened standing-wave laser oscillators are found to occur …

Tapered Radio Frequency Transmission Lines, Vincent D. Matarrese

Dissertations and Theses

A transformation used to obtain solutions for the beam parameter equation of fiber optics is applied to the second order differential equation for nonuniform transmission lines. Methods are developed for deriving possible transmission line tapers from known solutions of the transformed equation. This study begins with a comprehensive overview of previous work done to obtain closed-form solutions for the transmission line equations. Limitations of the lumped parameter model are also discussed. As part of this thesis, a tapered transmission line is constructed, based on one of the solutions obtained from the fiber optics studies. A discussion of the design and …