Engineering Commons^™

Defect Structure, Nonstoichiometry, And Phase Stability Of Ca-Doped Ycro3, G. F. Carini, Harlan U. Anderson, M. M. Nasrallah, Don M. Sparlin

Materials Science and Engineering Faculty Research & Creative Works

The dependence of the defect structure of Ca-doped YCrO₃ on oxygen activity and temperature was investigated by high temperature thermogravimetric measurements. Defect models developed from electrical conductivity data obtained in a previous study were used to interpret the thermogravimetric data. A correlation was found between the electrical conductivity and the thermogravimetric data which suggested that these data were concomitantly dependent on the acceptor dopant and oxygen vacancy dependance of the thermodynamic parameters. Kröger-Vink type diagrams showing the regions of stability with respect to oxygen activity and temperature were constructed. The TGA data show that Ca-doped YCrO₃ is even …

Positron Study Of Defects And Diffusion Induced Grain Boundary Migration In A Pb-Sn System, A. Belaidi, Hollis P. Leighly, H. Aourag, B. Khelifa, M. Oubadi, A. Elias

Materials Science and Engineering Faculty Research & Creative Works

The Pb-Sn system discloses a remarkable effect at the intermediate α → α + β phase boundary. The observation of the sharp transient peak in the S-parameter curve which is analogous to those found in thermal capacity curves is, as far as the authors are aware, unique in such positron measurements. This effect is interpreted in terms of positron trapping in defects associated with the strains accompanying the initial stage of transformation. This short note offers a new approach to the underlying phenomenon published in J. Phys. F. Met. Phys., 12 (1982) 813 by A. Belaidi, H. P. Leighly Jr. …

Electrical Conductivity, Seebeck Coefficient And Defect Chemistry Of Ca-Doped Ycro3, G. F. Carini, Harlan U. Anderson, Don M. Sparlin, M. M. Nasrallah

Materials Science and Engineering Faculty Research & Creative Works

The electrical transport behavior and defect structure of Ca-doped YCrO₃ were studied using electrical conductivity and Seebeck coefficient measurements as a function of oxygen activity and temperature. Defect models derived from the electrical conductivity data were found to adequately relate the concentration of charge carriers to the acceptor dopant and oxygen vacancy concentrations. Thermodynamic properties were calculated and found to be consistent with the model. Activation energy and carrier mobility data were also obtained. The analysis of the electrical conductivity, Seebeck and mobility data suggest that the conduction process in Ca-doped YCrO₃ occurs via the small polaron hopping …

Effects Of Sample Orientation On The Corrosion Of Zinc In Ammonium Sulfate And Sodium Hydroxide Solutions, D. Abayarathna, Edward Boyd Hale, Thomas J. O'Keefe, Y. M. Wang, D. Radovic

Physics Faculty Research & Creative Works

The corrosion and electrochemical properties of three zinc single crystal surfaces with different orientations have been investigated. In near-neutral 1 M (NH₄)₂SO₄, the corrosion rates on all three surfaces were found to be similar. However, the SEM morphologies of the corresponding corroded surfaces were markedly different from each other, but consistent with preferential attack of {1120} surfaces. In alkaline 0.5 N NaOH solution, the three sample orientations showed significantly different reactivities, with the (1120) surface exhibiting the highest reactivity and corrosion rate. Here, passivation ultimately occurred and the difference in the corrosion performance of …

Parplum : A System For Evaluating Parallel Program Optimization Methods, Jingsong Fu

Dissertations and Theses

The diversity of application programs and parallel architectures makes the mapping problem complicated and hard to evaluate. The quality of mapping is machine and application dependent and varies due to inaccurate values of application and architecture characteristics.

A system for developing, applying and evaluating mappings must have four characteristics: (1) Simplicity: A mapping procedure can be evaluated by separately evaluating its submapping, so the complicated problem can be simplified. (2) Generality: A wide range of application programs and architectures can be easily represented and all mapping algorithms can be easily implemented. (3) Multifunctionality: all the mapping steps, application programs, target …

Interim Report: Embankment Widening And Grade Raising On Soft Foundation Soils, Example I - Indiana State Route 55 Over Turkey Creek In Lake County, Indiana, Scott J. Ludlow, Wai-Fah Chen, Philippe L. Bourdeau, C. W. Lovell

JTRP Technical Reports

No abstract provided.

Driving Of Thin Shells For Steel Encased Concrete Piles, G. Agrawal, Jean-Lou Chameau

JTRP Technical Reports

The major purpose of this study was to identify the causes for the driving difficulties often given experienced on highway projects where thin shells are used for cast-in situ concrete piles that support bridge approaches, and to develop a set of recommendations and procedures to enable INDOT engineers to (a) make use of available technology for dynamic analysis of pile driving; and (b) make appropriate changes in the design, construction and contract specification procedures to improve identification and correction of problems at the earliest possible stage.

This study indicates that the parameter of greatest importance for most projects is the …

User Guide For Pc-Stabl3d, Gennady Moshkovich

JTRP Technical Reports

PC-STABL3D is the program for IBM PC compatible computers, developed to handle general stability analysis of three-dimensional slopes. Random generation routines are invoked to create trial failure surfaces, which are analyzed using the limiting equilibrium approach. The current version of PC-STABL3D is enhanced by a graphical pre/postprocessor, which facilitates creation and edition 0 data files, examination of problem geometry, and analyzing of the obtained failure surfaces. After the failure surfaces are generated and their factors of safety are computed, the program performs statistical analysis of received factors of safety, and calculates minimum statistical factor of safety. The information about minimum …

Accident Reduction Factors For Indiana, Daniel Joseph Ermer, Kumares C. Sinha

JTRP Technical Reports

This report presents the results of a study conducted to develop appropriate accident reduction factors associated with various highway improvement projects in Indiana. The factors were developed through a before-and-after analysis of accident data from 1983 to 1987. Disclaimer: This report presents the results of statistical analyses applied to available data. The accident reduction factor values do not imply any endorsement of any particular project types by the Federal Highway Administration or the Indiana Department of Transportation or the Joint Highway Research Project of Purdue University.

Engineering Soils Map Of Jay County, Indiana, Arvind Chaturvedi, Andrew Garrigus

JTRP Technical Reports

The soils mapping of Jay County was done primarily by the analysis of landforms and associated parent materials as portrayed on stereoscopic aerial photographs. Valuable information for soils was obtained from publications of the Soil Conservation Service, United States Department of Agriculture. Test data from roadway and bridge projects was obtained from the Indiana Department of Transportation. Soil profiles for the landform/parent material areas mapped are presented on the engineering soils map, a copy of which is included at the end of the report.

Application Of Rapid Asphalt Content Test To Slag Mixes, Douglas Windslow

JTRP Technical Reports

The "nuclear" asphalt content gage was used with bituminous mixes containing slag aggregates to assess its applicability as a rapid analysis tool for these types of mixes. It was found to work as well, or better, than the standard extraction technique. It was also found to have additional advantages over the extraction technique since it is about an order to magnitude faster, requires no solvent and involves no decisions on the part of the user.

The Impact Of Highway Services And Expenditures On Regional Economic Development, Paulus Cornelius Lombard, Kumares C. Sinha, Deborah J. Brown

JTRP Technical Reports

This report presents results from a study to determine the relationship between highway infraatructure and economic development in Indiana. Regression models and a computer model were developed to estimate the annual long-term impacts of highway construction on economic growth. Results from an analysis of economic impacts of the construction of 13 four-lane highway sections in Indiana, as well as an analysis of national data concerning industrial location determinants, are also presented.

The Development Of Optimal Strategies For Maintenance, Rehabilitation And Replacement Of Highway Bridges, Vol. 1: The Elements Of The Indiana Bridge Management System (Ibms) : Executive Summary, Kumares C. Sinha, Mitsuru Saito, Yi Jiang, Sudhir Murthy, Ah Beng Tee, Mark D. Bowman

JTRP Technical Reports

No abstract provided.

Automated Construction Data Management System : Executive Summary, Bob G. Mccullouch

JTRP Technical Reports

No abstract provided.

A Sensitivity Analysis Of The Parameters For A Cap Plasticity Model : Interim Report, Scott J. Ludlow, Wai-Fah Chen, Philippe L. Bourdeau, C. W. Lovell

JTRP Technical Reports

No abstract provided.

Traffic Speed Report No. 124: Traffic Report, David L. Cochran, Donald W. Genda

JTRP Technical Reports

No abstract provided.

Automated Construction Data Management System, Bob G. Mccullouch

JTRP Technical Reports

No abstract provided.

Speed Trends On Indiana Rural Interstate Highways : Traffic Report, David L. Cochran

JTRP Technical Reports

No abstract provided.

Effect Of Passive Flow-Control Devices On The Drug Of A Tractor-Trailer Model, Jagjit K. Ahuja

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic drag of tractor trailers is responsible for approximately half of the fuel consumption at highway speeds (55m.p.h.). Thus, it is important that vehicle drag be reduced in order to reduce operating costs and to conserve fuel. The purpose of the subject research conducted in the Old Dominion University Low-Speed Wind Tunnel was to determine the effect of various add-on flow-control devices, such as a cab-mounted flow deflector and gap seals between the tractor and the trailer. In addition, the effect of trailer rear-edge shaping has been studied. This was accomplished by contouring the trailer's rear end. It has …

Multiple Input Node Dataflow Processor Architecture, Gokhan Kuru

Theses and Dissertations

A new dataflow concept, Multiple Input Node is introduced to overcome the performance and efficiency degradation problems that exist in the current dataflow computation models where the computation unit, node, accepts 2 tokens at a time. Multiple Input Node is a new computation node which has 4 inputs, hence it can accept up to 4 token packets at a time. It can perform any simple arithmetic operation or combination of operations on these 4 input tokens. It is represented by a single instruction and performs the operations in a single instruction execution. This unique Multiple Input Node architecture reduces the …

Bioconcentrations Of Heavy Metals Copper, Chromium (Tot), Lead, Zinc, Nickel And Mercury In The Missouri River 1991

United States Army Corps of Engineers, Omaha District

The presence of heavy metals within aquatic environments can be attributed to sources such as industry, municipal discharges, agriculture and natural processes which release various amounts into natural systems. Metals such as copper, zinc and chromium are listed as essential micronutrients for many plant and animal species. Of potential concern, however, is the tendency of heavy metals to accumulate within the food webs of ecosystems. Classified as biologically hard to degrade, heavy metals may concentrate to significant amounts within the trophic levels of a particular ecosystem. At these increased concentrations many of these heavy metals become toxic to living organisms. …

Lewis M. Gould Papers, Zach S. Henderson Library Special Collections

Finding Aids

This collection consists of the writings and personal papers of Lewis M. Gould. Materials span 1918-1991 and include his writings for Stars and Stripes, poems, and various clippings.

Find this collection in the University Libraries' catalog.

Study Of Ingaas-Based Modulation Doped Field Effect Transistor Structures Using Variable-Angle Spectroscopic Ellipsometry, S. A. Alterovitz, R. M. Sieg, H. D. Yao, Paul G. Snyder, John A. Woollam, J. Pamulapati, P. K. Bhattacharya, P. A. P. A. Sekula-Moise

John A. Woollam Publications

Variable-angle spectroscopic ellipsometry was used to estimate the thicknesses of all layers within the optical penetration depth of InCaAs-based modulation doped field effect transistor structures. Strained and unstrained InGaAs channels were made by molecular beam epitaxy (MBE) on InP substrates and by metal-organic chemical vapor deposition on GaAs substrates. In most cases. ellipsometrically determined thicknesses were within 10% of the growth-calibration results. The MBE-made InCaAs strained layers showed large strain effects, indicating a probable shift in the critical points of their dielectric function toward the InP lattice-matched concentration.

Analytical And Experimental Investigation On Vibration Control Of Piezoelectric Structures, M. J. Tzeng, W-Z Ben Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Active vibration control of smart structural materials (beam and plate) has been achieved by using distributed piezoelectric actuators. Numerical simulation and experimental testing have been conducted to investigate vibration suppression of the advanced structures. Results from simulation and testing are in satisfactory agreement.

Instability And Collapse Behavior Of A Seismic Structure, Franklin Y. Cheng, Jeng Fuh Ger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The collapse behavior of a 22-story steel building during the September 19, 1985, Mexico earthquake is investigated by studying hysteretic behavior, ductility factors of individual structural components, and overall instability of the building. The hysteresis models for truss-type girders, bracing members, and box columns to be used in the inelastic analysis of this building are developed. A series of inelastic analyses have been performed for the building by using the multicomponent seismic input of actual Mexico City earthquake records. It was found that the structural response exceeds the original design ductility of this building because most girders in the building …

Uplift Capacity Of Z-Purlins, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Roof systems constructed using cold-formed steel components, i.e., Z-shaped purlins and interconnected roof panels, have become a very popular form of construction. This roof system is used extensively for single-story commercial and industrial buildings in the United States. The popularity of cold-formed steel members is due in part to their superior gravity load strength-to-weight ratio; however, because of their relatively light weight, a cold-formed member is very susceptible to wind uplift loading. The design specification in the United States for cold-formed steel construction does not provide a comprehensive analytical solution to the problem of wind uplift strength of a cold-formed …

Cold-Formed Steel Z-Sections With Sloping Edge Stiffness Under Axial Load, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Adaptive Gain Control And Contrast Improvement For Medical Diagnostic Ultrasound B-Mode Imaging System Using Charge-Couples Devices, Alan W. Bryant, Thomas J. Herrick

Electrical and Computer Engineering Faculty Research & Creative Works

A B-mode ultrasound imaging system operates by transmitting a high-frequency sound pulse and measuring the strength and time of flight of the reflected signal. The ultrasound signal may be attenuated as much as 60 dB in its round trip to a target and must be normalized so that contrast is not lost in the far field. Manual controls for adjusting receiver gain versus depth are common in many clinical uses but are impractical in most surgical applications. The goal of this project was to design a circuit to automatically adjust the gain. A two-dimensional low-pass filter is used to approximate …

Analysis Of Shear Banding In Plane Strain Compression Of A Bimetallic Thermally Softening Viscoplastic Body Containing An Elliptical Void, Z. G. Zhu, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We study plane strain thermomechanical deformations of a prismatic viscoplastic body of square cross-section and deformed at a nominal strain-rate of 5000 s-1. The body has two thin layers placed symmetrically about the horizontal centroidal axis and an elliptical void at the center. The major axis of the void coincides with the vertical centroidal axis and also with the direction of loading. The layer material differs from that of the body in only the value of the yield stress in a quasistatic simple compression test. The yield stress for the layer material is taken to be either one-fifth or five …

An Optoelectronic Adaptive Resonance Unit, Donald C. Wunsch, T. P. Caudell, R. A. Falk, C. David Capps

Electrical and Computer Engineering Faculty Research & Creative Works

The authors demonstrate a hardware implementation of the adaptive resonance theory ART 1 neural network architecture. The optoelectronic ART1 unit, is a novel application of an old device. This device-the 4-f or Van der Lugt correlator-has historically been used as a fast pattern classifier. Usually the correlation operation is employed as a matched filter, so that a maximum correlation peak corresponds to a well-matched pattern. The device described also uses the large peaks, but takes specific advantage of the fact that a zero-shift correlation is mathematically equivalent to a two-dimensional inner product. The authors describe a promising method for emulating …