Engineering Commons^™

An Investigation On The Processing And Characterization Of (Thallium(0.5-X) Lead(0.5-X) Europium(2x)) Strontium(2-Y) Barium(Y) Calcium(2) Copper(3) Oxygen(Z) High-Temperature Superconductor To Determine The Optimum Barium Concentration And Study The Effects Of Doping Europium In Thallium And Lead Sites, Zifan Ju

Dissertations and Theses @ UNI

This research focused on (Tl_0.5-xPb_0.5-xEu_2x)Sr_2-y Ba_yCa₂Cu₃O_z compound to determine the optimum y (Barium concentration), and then studied the effects of doping Eu in Tl, Pb sites. Studies on optimum y give rise to a high quality superconducting material as a target material for sputter deposition of thin films for electronics applications. Studies on doping Europium (Eu) is a new investigation and might lead to better understanding of the structural properties of the superconductor.

The experiment was conducted in three steps as follows:

1. Optimizing the sample fabrication …

A Comparison Of Measurement Reliability Between A Sonic Digitizer And A Tape Measure On A Complex Three-Dimensional Object, Diane Darlene (Wheeler) Schou

Dissertations and Theses @ UNI

Digitizers and scanners have begun to replace traditional devices for measuring three dimensional objects. However, there is a shortage of relevant research to compare digitizer tools with other measuring devices. The objective of this study was to compare the measurement reliability of a sonic digitizer to a traditional measuring tool, the tape measure, for measuring a complex, three-dimensional object. It was hypothesized that:

1. H₁ Data from measurements with the digitizer vary less than data from measurements with a tape measure at the 0.05 level of significance.
2. H₂ The data from eight complex surface measurements taken with a digitizer …

An Investigation On Using Solid Waste Materials As Aggregate Substitute In Cementitious Concrete Composites, Ibrahim Hussein Shehata

Dissertations and Theses @ UNI

The problem of disposing and managing solid waste materials in the United Slates and other industrial countries has become one of the major environmental, economical, and social issues. A complete waste management system including source reduction, reuse, recycling, landfilling, and incineration needs to be implemented to control the increasing waste disposal problems. Of the above options, recycling is the most promising waste management process to the disposal of materials in the waste stream. One of the most promising markets to utilize recycled waste materials successfully on an open-loop basis is the construction industry.

The purpose of this research study was …

Effect Of Light Source On The Sorting Performance Of A Vision-Based Robot System, Johnny T. Li

Dissertations and Theses @ UNI

Industries look toward computer vision as a means to automate materials handling. To make this choice more appealing, useful and feasible vision applications must be explored. However, illuminance variation in the factory environment can undermine the capability and applicability of vision-based control systems. The purposes of this study were (a) to design and develop a vision-based robot material sorting system, (b) to determine the optimal settings for this system under fluorescent and incandescent lighting for two different color parts on a moving conveyor, and (c) to determine the sorting performance of this system under each light source.

The main components …

Generalized Beam Matrices. Ii. Mode Selection In Lasers And Periodic Misaligned Complex Optical Systems, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

A generalized beam matrix method is used to investigate the mode structure of astigmatic misaligned optical systems with loss or gain. In these optical systems the usual real-argument polynomial-Gaussian beams are not eigenfunctions, and off-axis complex-argument polynomial beams must be used. New beam transformations for these complex-argument modes are reported. Stability criteria are developed, and mode selection in laser resonators that contain tilted, displaced, or curved complex optical elements is discussed.

Global Optimization Studies On The 1-D Phase Problem, Martin Zwick, Byrne Elliot Lovell, Jim Marsh

Complex Systems Faculty Publications and Presentations

The Genetic Algorithm (GA) and Simulated Annealing (SA), two techniques for global optimization, were applied to a reduced (simplified) form of the phase problem (RPP) in computational crystallography. Results were compared with those of "enhanced pair flipping" (EPF), a more elaborate problem-specific algorithm incorporating local and global searches. Not surprisingly, EPF did better than the GA or SA approaches, but the existence of GA and SA techniques more advanced than those used in this study suggest that these techniques still hold promise for phase problem applications. The RPP is, furthermore, an excellent test problem for such global optimization methods.

The Control Of A Process With Time Delay By Using A Modified Smith Predictor Compensator, Aidan O'Dwyer, John Ringwood

Conference papers

A modification is proposed to the Smith predictor compensator structure for the control of a process with time delay. The modification facilitates the achievement of an improved closed loop system regulator response, with little degradation in the corresponding servo response. The compensator design procedure is discussed, and simulation results are provided to demonstrate the applicability of the method.

Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this article we report steady, two-dimensional, inviscid solutions for the near field and far field of a supersonic reactive flow over a variable-double-ramp geometry. The incident shock wave compresses and heats the reactants that will combust after flowing some induction length. Upon reaction, a detonation wave forms and intersects the leading wave at some distance from the ramp surface. In this article, reaction-polar diagrams are developed, and the detonation branch solutions are used to investigate the wave interaction processes that may lead to a steady three-wave structure. By considering this formation process new oblique detonation wave stabilization criteria based …

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.

Liquid Phase Behaviour In Nonstoichiometric Calcium-Doped Lanthanum Chromites, J. D. Carter, M. M. Nasrallah, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The sinter ability of (La,Ca)CrO3 is analyzed by comparing the liquid phase behavior in A-site excess and A-site deficient compositions (referring to the ABO3 formula). The analysis shows that a series of A-site excess and deficient compositions form distinct liquid phases belonging to the CaO-Cr2O3 phase system. Although both series experience grain growth and densification due to the presence of a liquid phase, the A-site excess compositions exhibit greater shrinkage and sinter to closed porosity, whereas the A-site deficient compositions remain porous. During the final stages of sintering, surplus liquid from the A-site excess material exudes to the free-surface forming …

Simulator For The Performance Analysis Of Cpm Schemes In An Indoor Wireless Environment, Ronald Chua

Theses : Honours

A software simulator for characterising Continuous Phase Modulation (CPM) schemes in an indoor multipath environment has been developed using SIMULINK and MATLAB. The simulator is capable of simulating a wide range of CPM schemes to determine bandwidth efficiency and robustness to additive white Gaussian noise (AWGN) and Rician fading. Initial trials of the simulator indicate that the simulator is functioning correctly. Eventually, the simulator will be used to determine the most suitable modulation scheme for the development of an actual indoor wireless system.

Simulink Implementation Of A Cdma Transmitter, Visalakshi Ramakonar

Theses : Honours

An implementation of a Code Division Multiple Access (CDMA) transmitter has been developed using SIMULINK and MATLAB. This transmitter uses a modified carrier in modulation. This modified carrier, which is frequency modulated, has been shown to reduce intersymbol interference (ISI) and multiple access interference (MAl). These two types of interference are caused by multipath propagation which results in delayed versions of the original signal. The benefits of this modified modulation technique are apparent when there are delays involved. The spreading sequences used are 7- bit Gold codes which allow a maximum of nine users. The initial trials of the transmitter …

Growth And Properties Of Chemically Deposited Cds Thin Films, Edward A. Gluszak

Theses : Honours

Polycrystalline thin films of undoped CdS and In doped CdS (i.e. CdS:In) have been deposited by chemical bath on glass slides and high purity silicon wafers. The effect of different processing conditions (e.g. substrate temperature, doping and air annealing) on film growth, optical transmittance and electrical properties were correlated with the film microstrucutre. The mechanism of chemical bath deposition of CdS thin films from the ammonia-thiourea system is studied. The influence of reaction parameters (i.e. concentration of reactants and pH) on film growth were determined and modeled. Thin film growth is thermally activated with an energy ≈ 5 x 10 …

Laboratory Study On The Use Of Tire Shreds And Rubber-Sand In Backfilled And Reinforced Soil Applications, Andres Bernal, C. W. Lovell, Rodrigo Salgado

JTRP Technical Reports

Millions of scrap tires are discarded annually in the United States, the bulk of which are currently landfilled or stockpiled. This consumes valuable landfill space, or, if improperly disposed, creates a fire hazard and provides a prolific breeding ground for rats and mosquitoes. The use of tire shreds as lightweight fill material can sharply reduce the tire disposal problem. The present study, based on laboratory testing and numerical modeling examines the feasibility of incorporating tire shreds and rubber-sand mixtures as lightweight geomaterial in embankments and backfills. The growing interest in utilizing waste materials in civil engineering applications has opened the …

Estimating Statewide Trip Tables From Vehicle Classification Counts, James Yang, Jon D. Fricker

JTRP Technical Reports

Although a statewide trip table is an important ingredient in the statewide planning process, such information is difficult to obtain. The study described in this report investigated the applicability to the state-level problem of existing software developed to estimate trip tables in urban areas (or smaller) from link counts. Criteria that would form the basis for determining the applicability of any particular software package were developed. Packages such as The Highway Emulator (THE), PC-LINKOD, and Fast Matrix Calibration (FMC) were tested using small and medium sized networks. Because FMC performed the best on these tests, it was applied to the …

Remediation Of Hazardous Effluent Emitted From Beneath Newly Constructed Road Systems And Clogging Of Underdrain Systems, Ronald Fred Wukasch, Adil Siddiqui

JTRP Technical Reports

The Indiana Department of Transportation uses recycled concrete pavement as aggregate for the construction of highways. The effluent from these pavements has a high pH. The high pH effluent can cause clogging of drains and vegetative kill around the outlet. This project looks into the source of the effluent water, its chemical composition and the approximate duration the problem can be expected to persist. The project also investigates possible methods for reduction of the problem in future installation. The approximate additional cost of these solutions and the problems associated with them are discussed as well.

Mechanical Alloying Of Nitrogen Into Iron Powders, J. Rawers, D. Govier, D. C. Cook

Physics Faculty Publications

Mechanical alloying of nitrogen into bcc-fe powder is a very effective and efficient means of obtaining very high concentration of nitrogen in micron-size iron particles. Mechanical alloying increases the concentration of nitrogen in the iron powder far in excess of the bcc-Fe lattice low nitrogen solubility, however most of the infused nitrogen resides on the nano-size grain boundaries and in nano-size bct-fe that forms during mechanical alloying.

Analysis Of Transient Hydrogen Uptake By Metal Alloy Particles, Wenlin Zhang, Supramaniam Srinivasan, Harry J. Ploehn

Faculty Publications

This paper describes a new approach to solving the equations comprising the shrinking core model for diffusion and reaction of a chemical species in a solid spherical particle. The reactant adsorbs on the particle surface, diffuses into the particle's interior, and reacts with the particle to form a solid product. The shrinking core model assumes a fast reaction rate compared to reactant diffusion so that the reaction is localized in the interfacial zone between the unreacted solid core and the surrounding shell of reacted product. Analytical solutions of the governing conservation equations usually invoke the pseudo-steady state (PSS) approximation which …

A Multiphase Mathematical Model Of A Nickel/Hydrogen Cell, Pauline De Vidts

Faculty Publications

No abstract provided.

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc–Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, Ken-Ming Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …

Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin

Faculty Publications

Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …

A Model For The Galvanostatic Deposition Of Nickel Hydroxide, Mahesh Murthy, Gowri S. Nagarajan, John W. Weidner, John W. Van Zee

Faculty Publications

A mathematical model is presented for the galvanostatic deposition of Ni(OH)₂ films in stagnant Ni(NO₃)₂ solutions. The objective is to quantify the anomalous deposition behavior reported previously in which the utilization of the electrochemically generated OH^– species decreased drastically as the concentration of Ni(NO₃)₂ increased beyond 0.1 M. For example as the Ni(NO₃)₂ concentration increased from 0.1 to 2.0 M, the deposition rate decreased by a factor of ten at 2.5 mA/cm². At this high ratio of concentration to current density, a comparison with Faraday's …

Anodic Oxidation Of Ethylenediaminetetraacetic Acid On Platinum Electrode In Alkaline Medium, S. N. R. Pakalapati, Branko N. Popov, Ralph E. White

Faculty Publications

The anodic oxidation of ethylenediaminetetraacetic acid (EDTA) was studied in alkaline medium on a smooth platinum electrode. Bulk electrolysis indicated that stable organic intermediates (formaldehyde and glyoxal) are formed during the oxidation of EDTA and that complete oxidation to CO₂ can be achieved. The proposed pathway suggests that the acetate groups in EDTA are initially oxidized, generating formaldehyde and ethylenediamine. The rest potential of EDTA (0.066 to 0.164 V vs. Hg/HgO) was observed to be higher than for other organic species. In alkaline medium, very little EDTA oxidation was found to occur on bare platinum. Limiting-current behavior due to …

Anomalous Codeposition Of Fe-Ni Alloys And Fe-Ni-Sio2 Composites Under Potentiostatic Conditions, M. Ramasubramanian, S. N. Popova, Branko N. Popov, Ralph E. White, K. M. Yin

Faculty Publications

A mathematical model has been developed to describe the electrodeposition of Fe-Ni alloys and Fe-Ni-SiO₂ composites under potentiostatic conditions. This model can be used to predict the polarization behavior, partial current densities, and alloy composition of each of the components as a function of the applied potential. Fe-Ni-SiO₂ samples were deposited on platinum rotating disk electrodes from sulfate electrolytes under potentiostatic conditions, and the results obtained were compared to the model. The model predictions were found to agree well with the experimental observations for the Fe-Ni and Fe-Ni-SiO₂ systems.

Determination Of Transport And Electrochemical Kinetic Parameters Of Bare And Copper-Coated Lani4.27Sn0.24 Electrodes In Alkaline Solution, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

Electrochemical properties of bare and copper-coated LaNi_4.27Sn_0.24 electrodes were investigated in alkaline solution. The exchange current density, polarization resistance, and equilibrium potential were determined as functions of the state of charge in the electrodes. The symmetry factors for bare and copper-coated electrodes were estimated to be 0.53 and 0.52, respectively. By using a constant current discharge technique, the hydrogen diffusion coefficient in bare and coated LaNi_4.27Sn_0.24 was estimated to be 6.75 × 10^–11 cm²/s.

A New Pre-Loaded Membrane Geometric Stiffness Matrix With Full Rigid Body Capabilities, Paul A. Bosela, D. R. Ludwiczak

Civil and Environmental Engineering Faculty Publications

Space structures, due to economic considerations, must be light-weight. Accurate prediction of the natural frequencies and mode shapes is critical for determining the structural adequacy of components, and designing a control system. The total stiffness of a member, in many cases, includes both the elastic stiffness of the material as well as additional geometric stiffness due to pre-load (initial stress stiffness). The pre-load causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as ''grounding'', or false stiffening, of the stiffness matrix occurs during rigid body rotation. The author has previously shown …

Missouri River Gavins Point Dam Degradation Trends Study

United States Army Corps of Engineers, Omaha District

This report evaluates degradation trends of a study reach downstream of Gavins Point Dam. Basic pertinent data collected on various hydraulic and geomorphic elements and channel characteristics collected after the construction of the Gavins Point Dam are presented and evaluated. This volume will serve as a permanent record of most of the basic observations.

Pelargonic Acid In Enhanced Oil Recovery, Hossein Noureddini, M L. Rempe

Papers in Biomaterials

Oxidation of monounsaturated iatty ac~dss,u ch as erucic and oleic acids, results in the for~nation of dibasic fatty acids, such as brassylic and azelaic acids. Dibasic acids find many inclustrial applications. Prlargon~ca cid is the co-product oi the process. Expanded use oi dibasic acids would require an expansion in the existing and possihiy new uses for pelargoriic acid and its derivatives. In this study, the potential for using pe!argonic acid in enhanced oil recovery is investigated. Experimental results are presented ior the enhanccd oil recover" by waterilooding with the aid oi a surfactan;. In sifu iormation of surfactant at the …

Cycle Time Estimation For Simulating A Tandem Queueing Systems Using Aggregation Techniques, Paul Savory, Gerald Mackulak

Department of Industrial and Management Systems Engineering: Faculty Publications

One approach to simulating a single-server tandem queuing system is to explicitly model each of the production stages. In this paper, we apply queueing theory, a recursive algorithm, and composite random number sampling to develop an equivalent aggregate representation consisting of only a single production stage. Preliminary test results indicate that the aggregation works well for estimating the mean and variability of the total cycle time.

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 …