Engineering Commons^™

Tracking Thermal Saturation Fronts By A High Level Pc Programming Language, A. Erkal, Daopu Thompson Numbere

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This paper presents a PC based alternative procedure for determining the water saturations within the hot water zone of a thermal project for use in analytical oil recovery calculations. Conventional analytical calculation of oil recovery under steam and hot water injection requires the tracking of the movements of the saturations advancing within the variable-temperature hot-water zone. This involves an adaptation of the Buckley-Leverett theory to this variable temperature zone after dividing it into a number of constant temperature or isothermal zones. If the number exceeds two, the calculation can become very tedious unless done with a computer program. FORTRAN programs …

A Lattice Boltzmann Subgrid Model For High Reynolds Number Flows, S. Hou, James D. Sterling, S. Chen, G. D. Doolen

Business and Information Technology Faculty Research & Creative Works

A sub grid turbulence model for the lattice Boltzmann method is proposed for high Reynolds number fluid flow applications. The method, based on the standard Smagorinsky sub grid model and a single-time relaxation lattice Boltzmann method, incorporates the advantages of the lattice Boltzmann method for handling arbitrary boundaries and is easily implemented on parallel machines. The method is applied to a two-dimensional driven cavity flow for studying dynamics and the Reynolds number dependence of the flow structures. The substitution of other sub grid models, such as the dynamic sub grid model, in the framework of the LB method is discussed.

Computer Simulations Versus Real Experiments In A Portable Structural Mechanics Laboratory, Richard A. Behr

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Efforts are being made to develop practical and effective innovations for undergraduate engineering teaching laboratories. The 'ANEX' process, in which computer simulations are compared in nearly real time with physical measurements made on bench-scale model experiments, is now being used successfully in an introductory structural analysis course. ANEX is described, as well as current plans to develop software simulation modules and matched, bench-scale model experiments for new 'MECH-ANEX' laboratory applications in lower-division statics and mechanics of materials courses. The ANEX process could also be adapted to undergraduate laboratory applications in a wider range of engineering and science disciplines.

Phytoremediation: Plant Uptake Of Atrazine And Role Of Root Exudates, Joel G. (Gerard) Burken, Jerald L. Schnoor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoremediation is an Emerging Technology for Degradation of Organic Chemicals. the Potential of Phytoremediation in the Cleanup of Contaminated Sites and Prevention of Non-Point-Source Pollution Was Examined with the Pesticide Atrazine in Two Experimental Systems. Uptake Was Determined in Batch Experiments with 14C Ring-Labeled Atrazine and Hybrid Poplar Trees Grown in Two Soil Types. Mineralization Was Studied Utilizing Soil Microcosms with the Addition of Root Exudates. Results Indicate that Poplar Cuttings Were Able to Uptake the Majority of Applied Atrazine that Was Not Tightly Sorbed to the Organic Fraction of the Soil, with No Detectable Adverse Effects to the Trees. …

Behavior Of Low Ductility Steels In Cold-Formed Steel Connections, S. Seleim, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accepted design approaches for the strength of a steel connection rely on adequate ductility of the connected parts. In cold-formed steel connection design, adequate ductility is defined by the Specification for the Design of Cold-Formed Steel Members. To assess the influence of low ductility steels, i.e. steels not meeting the specification ductility requirements, single lap bolted connections were studied. The experimental study reflected key connection strength parameters: edge distance, sheet thickness, sheet width, bolt pattern, Fu/Fy, and percentage elongation. Test results indicate that failure modes in low ductility steels are inconsistent with observed failure modes in adequate ductility steels. It …

Seismic Test Methods For Architectural Glazing Systems, Richard A. Behr, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An ongoing effort is being made at the University of Missouri-Rolla to develop standard laboratory test methods and codified design procedures for architectural glass under seismic loadings. Recent laboratory work has yielded some promising results regarding the development of an appropriate seismic test method for architectural glass, as well as identifying ultimate limit states that quantify the seismic performance and damage thresholds of various glass types. Specifically, a straightforward "crescendo-like" in-plane dynamic racking test, performed at a constant frequency, has been employed successfully. Two ultimate limit states for architectural glass have been defined: (1) a lower ultimate limit state corresponding …

Modified Contactor For Experimental Studies Of Mass Transfer And Chemical Reaction Across A Liquid-Liquid Interface, Muthanna H. Al-Dahhan, Charles E. Wicks

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Modified Stirred-Cell Type Contactor Has Been Designed and Tested for its Use in Experimental Investigations of Mass Transfer and Chemical Reaction in Liquid-Liquid Systems. its Design overcomes the Shortcomings of Previously Proposed Contactors. It is Easy to Operate and Has the Ability to Investigate the Effect of a Wide Range of Operating Conditions. the Mixing Performance of the Contactor Was Tested using a Dye Injection and a Tracer Technique. Experiments to Evaluate Mass-Transfer Coefficients Across a Liquid-Liquid Interface Have Been Conducted to Determine its Effectiveness. the Results Verified that the Contactor Could Be Successfully Employed as a Useful Experimental …

Evaluation Of Trickle Bed Reactor Models For A Liquid Limited Reaction, Yuanxin Wu, Muthanna H. Al-Dahhan, Mohan R. Khadilkar, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Isothermal Decomposition of Hydrogen Peroxide on a CuCr Catalyst in a Laboratory Scale Trickle Bed Reactor Was Used to Test Model Predictions of the Dependence of Liquid Reactant Conversion on Space Time for Different Operating Conditions. It is Assured that the Decomposition of Hydrogen Peroxide is a First Order Liquid-Limited Reaction. Comparison of Model Predictions and Experimental Data Indicates that Both External Mass Transfer Effects and Incomplete External Catalyst Wetting Need to Be Accounted For. Dudukovic's (1977) Approximate Model for the Catalyst Effectiveness Factor Adequately Simulates Both Effects.

Comparison Of Trickle-Bed And Upflow Reactor Performance At High Pressure: Model Predictions And Experimental Observations, M. R. Khadilkar, Y. X. Wu, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic, M. Colakyan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Comparison of Laboratory Trickle-Bed and Up-Flow Reactors over a Range of Operating Conditions, Which Cover Both Gas and Liquid Reactant Limitations, Has Been Investigated using Hydrogenation of Alpha-Methylstyrene to Cumene in a Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. the Results Show that When the Reaction is Gas Limited at Low Pressure and High Liquid Feed Concentration, Trickle Bed Reactor Outperforms the Upflow Reactor. at High Pressure and Low Liquid Feed Concentration, the Reaction Becomes Liquid Limited and Upflow Reactor Performs Better. It is Concluded that the Advantage of Upflow or Downflow Depends on …

Unsteady Conjugate Mass Transfer Between A Single Droplet And An Ambient Flow With External Chemical Reaction, Leonid S. Kleinman, X. B. Reed

Chemical and Biochemical Engineering Faculty Research & Creative Works

Unsteady conjugate mass transfer between a spherical bubble, droplet, or particle and a surrounding fluid flow with chemical reaction in the continuous phase has been analyzed. An algorithm based on spectral methods has been developed and implemented for the simulation of the interphase mass transfer. The influence of Pe (convection) and Da (rate of external reaction), but in particular of D (diffusivity ratio) and H (distribution coefficient), which characterize the coupling features of the conjugate mass transfer, is studied in a wider range of parameters than earlier investigations. The asymptotic regime of mass transfer is investigated for long times, and …

High-Frequency Spin Waves In Yba₂Cu₃O6.15>/Sub>, Stephen M. Hayden, Gabriel Aeppli, Toby G. Perring, Herbert A. Mook, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Pulsed neutron spectroscopy is used to absolute measurements of the dynamic magnetic susceptibility of insulating YBa₂Cu₃O_6.15. Acoustic and optical modes, derived from inand out-of-phase oscillation of spins in adjacent CuO₂ planes, dominate the spectra and are observed up to 250 meV. The optical modes appear first at 74±5 meV. Linear-spin-wave theory gives an excellent description of the data and yields intralayer and interlayer exchange constants of J_∥=125±5 meV and J_⊥=11±2 meV, respectively, and a spin-wave intensity renormalization Z_Χ=0.4±0.1.

On Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Rigid retaining walls experience both sliding and rocking displacement during earthquakes. Richards and Elms' (1979) method incorporates only sliding displacements in design. A realistic method of computing both sliding and rocking displacements of the walls based on nonlinear soil properties both for the base soil and backfill was developed by Rafnsson and Prakash (1994). A design procedure based on this method was then developed by Prakash. et al (1995, b). Comparisons of the displacements of typical walls by both the methods have been made. Also, typical field data from recent earthquakes has been analyzed to compare the observed displacements with …

Bending And Shear Behavior Of Web Elements With Openings, M. Y. Shan, Roger A. Laboube, Wei-Wen Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Cold-formed steel C-sections are frequently used as wall studs and floor joists in both commercial and residential construction. To facilitate installation of ancillary systems such as electrical wiring and plumbing, the C-section is manufactured with a web opening. Although the opening offers construction advantages, it may degrade the structural integrity of the member. To quantify the degrading effect of a web opening, a study has been conducted at the University of Missouri-Rolla (UMR). The UMR study included the loading conditions of bending, shear, web crippling, and the combinations thereof. This paper summarizes the results of an experimental study which addressed …

Treatability Of S-Triazine Herbicide Metabolites Using Powdered Activated Carbon, Craig D. Adams, Tammy L. Watson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Widespread use of s-triazine herbicides such as atrazine, simazine, and cyanazine has led to the contamination of many ground-water and surface-water supplies with the parent compounds as well as by primary metabolites (e.g., deethylatrazine, deisopropylatrazine, and deethylcyanazine). Ozonation has been shown to produce many of the same byproducts. Activated carbon adsorption has been designated by the U.S. Environmental Protection Agency as the best available technology (BAT) for the treatment of herbicides in drinking water. Little data is available, however, on the applicability of activated carbon treatment for the control of the primary degradation products of herbicides. In this study, the …

Comparison Of Upflow And Downflow Two-Phase Flow Packed-Bed Reactors With And Without Fines: Experimental Observations, Yuanxin Wu, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

This Study Compares the Performance of Laboratory Trickle-Bed and Upflow Reactors over a Range of Operating Conditions, using the Hydrogenation of Α-Methylstyrene to Cumene in Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. It is Shown that the Trickle Bed Performs Better Than the Upflow Reactor at Low Pressures When the Reaction is Gas Limited, Due to Ready Access of the Gas to the Incompletely Externally Wetted Catalyst, While the Upflow Reactor Performs Better at High Pressures When the Liquid Reactant Limitation Controls the Rate, Due to the Completely Wetted Catalyst. Comparison of the Two …

Dynamically Regularized Fast Rls With Application To Echo Cancellation, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a dynamically regularized fast recursive least squares (DR-FRLS) adaptive filtering algorithm. Numerically stabilized FRLS algorithms exhibit reliable and fast convergence with low complexity even when the excitation signal is highly self-correlated. FRLS still suffers from instability, however, when the condition number of the implicit excitation sample covariance matrix is very high. DR-FRLS, overcomes this problem with a regularization process which only increases the computational complexity by 50%. The benefits of regularization include: (1) the ability to use small forgetting factors resulting in improved tracking ability and (2) better convergence over the standard regularization technique of noise injection. …

An Approach To Just-In-Time Implementation In Discrete Parts Manufacturing, Phillip Gregory Shirey

Masters Theses

"Just-In-Time manufacturing is a philosophy that encourages waste reduction and the elimination of non-value-added activities. The processes affected include office and shop personnel. When successfully implemented, JIT accounts for improved production lead time cycles, reduced inventories, improved employee morale, reduced cost of goods, and continuous improvements of the total business process.

This thesis identifies real world problems many medium size U.S. manufacturing companies now face, and an approach to JIT implementation in discrete parts manufacturing. The approach includes developing strategies to motivate the employees and to implement the tools and techniques of JIT, Total Quality Management, ISO 9001, and MRP …

Heat Transfer In Two-Phase Solid-Rocket Plumes, Harlan F. Nelson, John C. Fields

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Results of a direct simulation Monte Carlo (DSMC) and free molecule (FM) analysis of convective heat transfer to Al2O3 particles in solid-rocket plume environments are presented. The particle diameters are assumed to be 4μm, and the plume gases are CO2, H2O, CO, and N2. The plume gas temperature is 2000 K. Particle temperatures of 1500, 2000, and 2500 K are investigated for Knudsen numbers from 1/2 to 1000 (from slip flow to FM flow). The Nusselt number is presented in terms of Knudsen number and Reynolds number (or relative velocity). Both the Kavanau and the Kashmarov and Svirshevskii correlations generally …

Compliant Pliers, Ashok Midha, S. C. Visser

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The pliers include an endless loop, a top jaw appended to the endless loop, and a bottom jaw appended to the endless loop. The endless loop includes in series a top grip handle, a spring segment, a bottom grip handle and a compliant strip interconnecting the top and bottom grip handles. A rolling surface on the top grip handle rolls on a contact portion of the bottom grip handle. The rolling action causes the compliant strip to flex which causes the top and bottom jaws to move toward one another. The endless loop provides a built-in automatic spring and enhances …

A Hybrid Observer For High Performance Brushless Dc Motor Drives, Keith Corzine, S. D. Sudhoff

Electrical and Computer Engineering Faculty Research & Creative Works

Brushless DC motor drive systems are used in a wide variety of applications. These drives may be classified as being one of two types: sinusoidal drives in which there are no low-frequency harmonics in the current waveforms and no low-frequency torque ripple; and nonsinusoidal drives in which there is considerable low-frequency harmonic content, both in the current and torque waveforms. Although sinusoidal drives feature superior performance, they are generally more expensive since rotor position must be sensed on a continuous basis, thus requiring an optical encoder or a resolver, whereas relatively inexpensive Hall-effect sensors may be used for nonsinusoidal drives. …

Fault Classification Using Kohonen Feature Mapping, Badrul H. Chowdhury, Kunyu Wang

Electrical and Computer Engineering Faculty Research & Creative Works

Applications of neural networks to power system fault diagnosis have provided positive results and shown advantages in process speed over conventional approaches. This paper describes the application of a Kohonen neural network to fault detection and classification using the fundamental components of currents and voltages. The Electromagnetic Transients Program is used to obtain fault patterns for the training and testing of neural networks. Accurate classifications are obtained for all types of possible short circuit faults on test systems representing high voltage transmission lines. Short training time makes the Kohonen network suitable for on-line power system fault diagnosis. The method introduced …

Interaction Between Millimeter Oscillations And Monocrystal Hexagonal Ferrites With Modulated Resonance Frequency, Alexander A. Kitaytsev, Marina Koledintseva

Electrical and Computer Engineering Faculty Research & Creative Works

Investigation of non-linear stable effects taking place at ferromagnetic resonance (FMR) in monocrystal arbitrarily oriented hexagonal ferrite resonators (HFR) with controlled (modulated) resonance frequency is an urgent problem. The presented analysis is based on two approaches: the “quasistatic” approach using the static tensor of the HFR magnetic susceptibility and the “dynamic” one based on the solution of the magnetization vector motion equation (MVME) with varying time coefficients due to modulated magnetization field or HFR angle of orientation. The first approach is valid at low modulation frequencies (in comparison with the relaxation frequency of the HFR) and the second one can …

Automatic Pcb Inspection Algorithms: A Survey, Madhav Moganti, Fikret Ercal, Cihan H. Dagli, Shou Tsunekawa

Computer Science Faculty Research & Creative Works

The importance of the inspection process has been magnified by the requirements of the modern manufacturing environment. In electronics mass-production manufacturing facilities, an attempt is often made to achieve 100% quality assurance of all parts, subassemblies, and finished goods. A variety of approaches for automated visual inspection of printed circuits have been reported over the past two decades. In this survey, algorithms and techniques for the automated inspection of printed circuit boards are examined. A classification tree for these algorithms is presented and the algorithms are grouped according to this classification. This survey concentrates mainly on image analysis and fault …

Input Dimension Reduction In Neural Network Training-Case Study In Transient Stability Assessment Of Large Systems, S. Muknahallipatna, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The problem in modeling large systems by artificial neural networks (ANN) is that the size of the input vector can become excessively large. This condition can potentially increase the likelihood of convergence problems for the training algorithm adopted. Besides, the memory requirement and the processing time also increase. This paper addresses the issue of ANN input dimension reduction. Two different methods are discussed and compared for efficiency and accuracy when applied to transient stability assessment.

Transient And Dynamic Average-Value Modeling Of Synchronous Machine Fed Load-Commutated Converters, Keith Corzine, S. D. Sudhoff, H. J. Hegner, D. E. Delisle

Electrical and Computer Engineering Faculty Research & Creative Works

A new average-value model of a synchronous machine fed load-commutated converter is set forth in which the stator dynamics are combined with the DC link dynamics. This model is shown to he extremely accurate in predicting system transients and in predicting frequency-domain characteristics such as the impedance looking into the synchronous machine fed load-commutated converter. The model is verified against a detailed computer simulation and against a hardware test system, thus providing a three-way comparison. The proposed model is shown to be much more accurate than models in which the stator dynamics are neglected

Two Methods Of Neural Network Controlled Dynamic Channel Allocation For Mobile Radio Systems, Kelvin T. Erickson, Edward J. Wilmes

Electrical and Computer Engineering Faculty Research & Creative Works

Two methods of dynamic channel allocation using neural networks are investigated. Both methods continuously optimize the mobile network based on changes in calling traffic. The first method uses backpropagation model predictions to aid the channel allocator. Each cell contains a backpropagation model which provides the channel allocator a call traffic prediction allowing the channel allocator to effectively optimize the network. The second method uses the same backpropagation models along with actor-critic models to perform the channel allocation. The actor-critics learn to model traffic activity between adjacent cells in real-time, and thereby learn to allocate channels dynamically between cells. The learning …

Evaluating The Value Of Distributed Photovoltaic Generations In Radial Distribution Systems, Badrul H. Chowdhury, A. W. Sawab

Electrical and Computer Engineering Faculty Research & Creative Works

The impact of photovoltaic (PV) generations, when added to an existing rural utility's distribution system, is studied. The addition of PV is examined in the light of voltage support, loss reduction, and reduction in peak demand. Comparisons are made with the conventional and widely used methods for voltage control and loss minimization, such as the addition of series and shunt capacitors and voltage regulators. The economics of distributed PV systems in the context of conventional grid power purchases are also studied. Results of this study are meant to be used as general guidelines for evaluating the impact of significant PV …

Security-Constrained Optimal Rescheduling Of Real Power Using Hopfield Neural Network, S. Ghosh, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

A new method for security-constrained corrective rescheduling of real power using the Hopfield neural network is presented. The proposed method is based on solution of a set of differential equations obtained from transformation of an energy function. Results from this work are compared with the results from a method based on dual linear programming formulation of the optimal corrective rescheduling. The minimum deviations in real power generations and loads at buses are combined to form the objective function for optimization. Inclusion of inequality constraints on active line flow limits and equality constraint on real power generation load balance assures a …

Programmable Logic Controllers, Kelvin T. Erickson

Electrical and Computer Engineering Faculty Research & Creative Works

Programmable logic controllers (PLCs) are at the forefront of manufacturing automation. Many factories use programmable logic controllers to cut production costs and/or increase quality. PLCs and their unique language, ladder logic, are the workhorses of factory automation. Higher-level languages, such as sequential function charts and function blocks, ease the programming task for large systems. However, ladder logic remains the dominant language at present

Gas And Liquid Phase Transport In Pulsed Fuel Sprays, Pete D. Jennings, James A. Drallmeier

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An infrared extinction technique was used to characterize spatially and temporally the vapor phase of a transient fuel spray. Optical extinction data were taken at two laser wavelengths and compared to obtain fuel vapor partial pressure values averaged over the line-of-sight through the spray. A transient fuel injector spray was characterized at several axial positions with a spatial resolution of 0.125 cm and a temporal resolution of 0.2 ms. With the knowledge of an axisymmetric spray pulse, the line-of-sight averaged results were deconvoluted to obtain spatially resolved vapor pressure data. The same spray was also characterized using phase/doppler interferometry to …