Engineering Commons^™

A Wear Analysis Study Of Selected Alternative Foundry Tooling Materials Using Impact Abrasion Testing, L. Fred Vondra

Dissertations and Theses @ UNI

The purpose of this study was to simulate the wear characteristics of foundry tooling using an impact abrasion test apparatus. The wear characteristic was exhibited by non-metallic materials and was measured as a function of percentage weight loss and was benchmarked against Class 30 gray iron. The research question focused on whether or not a non-metallic material exists that exhibits comparable or superior wear characteristics to Class 30 gray iron for possible consideration as tooling materials for foundry applications. The information obtained adds to knowledge and is useful to foundry professionals in making tooling decisions.

The 34 test materials were …

Job Characteristics Of Construction Craftsmen And Their Relationships To Affective Work Outcomes, Musibau Adeola Shofoluwe

Dissertations and Theses @ UNI

This research was undertaken to investigate the extent to which employee-perceived job characteristics were related to internal work motivation and general satisfaction. Research shows that the structure of work has a significant influence on the motivation and general satisfaction of workers.

A job characteristic model developed by Hackman and Oldham (1980) was used as a basis for conducting this study. The study population consisted of construction craft workers who were registered members of the bricklayers, carpenters, and electrical unions located in a mid-western state. Job diagnostic survey questionnaires were mailed to 650 craftsmen. A total of 236 (36.3%) instruments were …

Review Of P-Type Doped Perovskite Materials For Sofc And Other Applications, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

p-type perovskite-type oxides are candidates for use as components of high temperature fuel cells and as oxygen separation membranes. The particular properties that these applications require are reviewed. The characteristics that these oxides have which allow them to satisfy many of these requirements are discussed and a defect model presented. The status of the utilization of these oxides and of the areas which need to be addressed such as thermal expansion and sintering characteristics are reviewed. © 1992.

Effect Of Cation Substitution On The Thermal Expansion Coefficient Of Lacro3, R. Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Tensile Fatigue Behaviour Of Tightly Woven Carbon/Carbon Composites, A. Ozturk, Robert E. Moore

Materials Science and Engineering Faculty Research & Creative Works

The tensile fatigue behavior of a tightly woven carbon/carbon composite was investigated as a function of stress level. Load-controlled fatigue tests were performed in tension-tension mode with a stress ratio, R, of 0.1 under ambient laboratory conditions. Results of composite behavior are discussed in terms of the relationship of the stress/strain behavior to the fatigue life of these composites as well as the effects of applied stress levels. It is shown that these composites exhibit good resistance to cyclic loading. No fatigue failures were obtained after 106 cycles when the maximum tensile load in the fatigue cycle is less than …

All Optical Clock Distribution With Synchronous Frequency Division And Multiplication, Gerald Farrell, P. Phelan, Joe Hegarty

Articles

A master optical clock from a mode locked laser is distributed to two slave twin section lasers. One slave laser divides the optical modulation frequency by 2, the other slave laser multiplies the frequency by 2. It is also possible to vary the multiplication4ivision ratio in a slave laser using only DC control of the absorber of the twin section laser.

Electrical Conductivity And Seebeck Coefficient Of (La, Ca) (Cr, Co)O3, R. Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

Electrical conductivity and Seebeck coefficients of (La, Ca) (Cr, Co)O₃ were measured as a function of temperature. The electrical conductivity as measured in air from 100 to 1100 °C increased with increasing Co and Ca content. The Seebeck coefficients were positive, indicating p-type conductivity. The substitution of Co for Cr significantly decreased the Seebeck coefficients, indicating that the substitution resulted in an increase in site occupancy, associated with the Co. The additional Ca substitution for La resulted in further decrease in the Seebeck coefficients, then exhibited a temperature-independent behaviour, indicating that the carrier mobility, rather than carrier concentration, was …

Grain Size Effect On The Induced Piezoelectric Properties Of 0.9pmn-0.1pt Ceramic, U. Kumar, Wayne Huebner, P. Marsh, H. Kankul, S. F. Wang, Clyde G. Oakley

Materials Science and Engineering Faculty Research & Creative Works

Lead magnesium niobate-lead titanate (Pb(Mg_1/3Nb_2/3)O₃ - PbTiO₃ (PT) solid solutions have been widely researched to produce devices that can be used in low- and high-electric-field applications. For some applications, such as medical ultrasonic transducers, it is necessary to prepare the ceramic with high density and small average grain size. The effect of grain size on the low- and high-field properties of 0.9-PMN-0.10-PT ceramics is described in the present work. To prepare highly dense ceramic, vibratory and attrition milled powders were sintered between 1000 and 1250 ⁰C. The average grain sizes of the sintered ceramics …

Method Of Making Highly Sinterable Lanthanum Chromite Powder, Von Richards, Subhash C. Singhal

Materials Science and Engineering Faculty Research & Creative Works

A highly sinterable powder consisting essentially of LaCrO.sub.3, containing from 5 weight % to 20 weight % of a chromite of dopant Ca, Sr, Co, Ba, or Mg and a coating of a chromate of dopant Ca, Sr, Co, Ba, or Mg; is made by (1) forming a solution of La, Cr, and dopant; (2) heating their solutions; (3) forming a combined solution having a desired ratio of La, Cr, and dopant and heating to reduce solvent; (4) forming a foamed mass under vacuum; (5) burning off organic components and forming a charred material; (6) grinding the charred material; (7) …

Solvent Extraction Reagent Entrainment Effects On Zinc Electrowinning From Waste Oxide Leach Solutions, M. Neira, Thomas J. O'Keefe, Johh L. Watson

Materials Science and Engineering Faculty Research & Creative Works

A considerable quantity of metal-containing waste oxide is generated by the primary metal industry, and under increased environmental regulation, treatment of these wastes has become viable. Hydrometallurgical processing is often appropriate and one potential treatment process for zinc oxide wastes involves leaching the oxide with an acid, purifying by a solvent extraction operation, and recovering metallic zinc by electrowinning the purified leach solution. The purification stage is frequently critical and the introduction of a solvent extraction organic reagent into the flowsheet can be detrimental to downstream processes. The object of this study was to determine the effect of organics, entrained …

Approaches To Control Of The Large Angle Magnetic Suspension Test Fixture, Mehran Ghofrani

Mechanical & Aerospace Engineering Theses & Dissertations

The Large Angle Magnetic Suspension Test Fixture is a five degree-of-freedom system, developed and built at NASA Langley Research Center. It is intended for study of control techniques in magnetic suspension systems with large angular capabilities. In this study, steps have been taken to prove the system in practice, using the existing hardware. A classical control approach, using dual phase advance compensators, is applied in simulation and hardware. A single decoupled degree-of-freedom of the system is stabilized and controlled in simulation. The procedure is then employed for all five degrees-of-freedom. The design and implementation of an analog and a digital …

Porting Chorus To The Pa-Risc: Virtual Memory Manager, Jon Inouye, Marion Hakanson, Ravi Konuru, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This document describes the port ofthe Chorus virtual memory manager to the Hewlett-Packard Precision Architecture rusc (PA-RISC) workstation. The information contained in this paper will be of interest to people who:

• intend to port the Chorus virtual memory section. • intend to port a virtual memory design to the Hewlett-Packard PA-RISC.

The reader is strongly encouraged to read the following PA-Chorus documents before reading this document:

• Technical Report CSE-92-3, Porting Chorus to the PA-RISC: Project Overview

Synthesis Study On Use Of Concrete Recycled From Pavement And Building Rubble In The Indiana Highway System, Thomas T. Burke, Menashi D. Cohen, Charles F. Scholer

JTRP Technical Reports

The demolition of buildings and highway pavements in the State of Indiana generates a considerable amount of waste materials. The disposal of these materials causes strain on the existing landfills which are rapidly approaching their full capacity. This study is a synthesis of the information on the use of concrete recycled from pavements and building rubble for use in the Indiana highway system. Test results have shown that recycled pavement concrete made chiefly from broken-up and crushed old concrete aggregate is as good as concrete made from virgin aggregate, and sometimes better. The aggregates made from recycled concrete can be …

Manual Of Traffic Impact Studies, 3 Volumes: Volume 1 - Final Report, Guidelines For Traffic Analysis Of Developments Along State Highways, Soumya Sekhar Dey, Jon D. Fricker

JTRP Technical Reports

With intensification urban development and dwindling public resources, assessing the impacts of a new development (traffic impact analysis) is becoming an important planning tool for transportation engineers, so that the traffic impacts of new developments can be foreseen and effective mitigating measures can be planned using optimal allocation of the available funds. The study establishes a detailed and standardized methodology for traffic impact analysis. Although the procedure was developed for the Indiana Department of Transportation, it can be used by other transportation agencies as well with little or no modification.

A new methodology for estimating the percentage of pass-by trips …

Implementation Of The Indiana Bridge Management System, User's Manual, Lisa Chow Gion, Justin Gough, Jeffrey Dunn Vitale, Kumares C. Sinha, Robert E. Woods

JTRP Technical Reports

This report provides a user's manual for the implementation of the project evaluation and program development part of the Indiana Bridge Management System (IBMS). The tools and techniques found in these programs were primarily developed from previous research by the Joint Highway Research Project at purdue University. The IBMS runs on an IBM-compatible computer under 05/2.

Laboratory Evaluation Of Prefabricated Highway Edge Drains, Ahmed Mohamed Elsharief

JTRP Technical Reports

This study evaluated prefabricated highway edge drains to improve the existing practice and to set guidelines for their proper selection. Two primary evaluations received attention: the first was the effect of installation and in service loading on the hydraulic and strength capacities of a prefabricated highway edge drain; and the second was the performance of the geotextile filter.

A limited field evaluation of prefabricated highway drains indicated structural failure of the core and an inefficient geotextile. Based on, the field study, laboratory testing and theoretical modeling, guidelines were given for the strength and hydraulic requirements of the drain. A retention …

The Use Of Advanced Technologies In Indiana Department Of Transportation, Thomas R. Kruse, Kumares C. Sinha, Ted M. Andrews, Jon D. Fricker, James Samuel Bethel, Michael J. Cassidy, Jorge A. Vanegas

JTRP Technical Reports

The report presents the findings of a study that investigated the potential uses of new technologies in INDOT. A survey of state transport agencies were conducted and the major groups of technologies identified are: CADD, GIS, Advanced Survey Techniques, Knowledge-Based Expert Systems, Planning and Programming Mdels, and a workshop with the INDOT executive staff were conducted to determine the priority areas for advanced technology applications. Suggestions were then made for the development of a new technology program within INDOT.

Fatigue Strength And Evaluation Of Sign Structures, Volume 1: Analysis And Evaluation, Xuejun Li, Timothy M. Whalen, Mark D. Bowman

JTRP Technical Reports

This report is a two-volume final report presenting the findings of the research work that was undertaken to evaluate the fatigue behavior of sign structures and, based on that evaluation, to recommend an inspection plan that can be effectively used to detect and minimize possible deterioration due to wind induced loadings of sign structures. The study included a number of signs that are commonly used in Indiana: single-mastarm and double-mastarm cantilever sign structures, box-truss sign structures, tri-chord sign structures, and monotube sign structures. Sign structures with typical dimensions and details were selected as prototypes for each of the various types …

The Development Of A Highway Revenue Forecasting Model For Indiana : Executive Summary, Amit H. Varma, Kumares C. Sinha, Jeffrey L. Spalding

JTRP Technical Reports

No abstract provided.

Development Of Quality Assurance Specifications For Bridge Painting Contracts, Luh M. Chang, Machine Hsie, David Unkefer

JTRP Technical Reports

No abstract provided.

Potential Use Of Tire Rubber And Ebonite In Asphalt: Synthesis Study, Abidin Kaya

JTRP Technical Reports

No abstract provided.

The Development Of A Highway Revenue Forecasting Model For Indiana, Amit H. Varma, Kumares C. Sinha, Jeffrey L. Spalding

JTRP Technical Reports

No abstract provided.

Potential Use Of Tire Rubber And Ebonite In Asphalt: Synthesis Study : Executive Summary, Abidin Kaya

JTRP Technical Reports

No abstract provided.

Use Of Waste Foundry Sand In Highway Construction : Interim Report, Sayeed Javed

JTRP Technical Reports

No abstract provided.

Laboratory Study On Properties Of Rubber Soils : Interim Report, Imtiaz Ahmed

JTRP Technical Reports

No abstract provided.

Mathematical Modeling Of A Primary Zinc/Air Battery, Z. Mao, Ralph E. White

Faculty Publications

The mathematical model developed by Sunu and Bennion has been extended to include the separator, precipitation of both solid ZnO and K₂Zn(OH)₄, and the air electrode, and has been used to investigate the behavior of a primary Zn-Air battery with respect to battery design features. Predictions obtained from the model indicate that anode material utilizationis predominantly limited by depletion of the concentration of hydroxide ions. The effect of electrode thickness on anode material utilization is insignificant, whereas material loading per unit volume has a great effect on anode material utilization; a higher loading lowers both the …

Calorimetric Determination Of The Thermoneutral Potential Of Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White, E. C. Darcy

Faculty Publications

Through a continuous recording of the cell voltage, heat flow, and current, the effective thermoneutral potential, E_etpof Li/BCX and Li/SOCl₂ cells were determined in the temperature range, 0–60°C. The depth of discharge (DOD), temperature (T), and cell type (cell chemistry) affect the effective thermoneutral potential. The effective thermoneutral potential, E_etp differs from the classical thermoneutral potential of a cell because it takes into account the heat flow due to non-faradaic processes. The average effective thermoneutral potential at 25°C (determined by selecting the most constant region of E_etp vs. time of discharge) was 4.0 …

Comparing Electrochemical Impedance Spectroscopy Methods For Estimating The Degree Of Delamination Of Organic Coatings On Steel, S. A. Mccluney, S. N. Popova, Branko N. Popov, Ralph E. White, R. B. Griffin

Faculty Publications

Electrochemical impedance spectroscopy (EIS) was used to evaluate the degree of delamination of the epoxy primer Uniprime ED-4¹ electrocoated on phosphate-treated cold-rolled steel in 3.5% NaCl exposed to air. Specimens with coating thicknesses of 20.3 and 20.8 µm and surface areas of 78.5 cm² were used. Coating parameters were obtained using a circuit-analog model. The area of delamination was estimated using several EIS parameters, including the pore resistance and the break point frequency. These values were compared to the corroded area determined visually. All methods considered exhibited a strong correlation over some or all of the range of …

Factors Affecting The Development Of Unassigned Patents In Iowa, Diane Darlene Wheeler Schou

Dissertations and Theses @ UNI

Inventors granted patents from 1975 to 1990 in Iowa identified, via a questionnaire, where they perceived their invention on Bright's scale of eight stages of development. Stages were: idea, rationalization (has merit), experimentation, demonstration of prototypes, working model, commercial (market entry), commercial acceptance (sales), and commercial proliferation (other markets). The questions identified factors affecting development. The factors included: resources assisting development, events influencing start-up, sources of money for development, method of manufacturing, experiences with manufacturers, marketing techniques, sales, profit/loss, concerns, patent renewals, and age of patents. Open-ended questions allowed for additional comments.

Commercial acceptance or commercial proliferation was achieved by …

Bounds On Constraint Weight Parameters Of Hopfield Networks For Stability Of Optimization Problem Solutions, Gursel Serpen

Electrical & Computer Engineering Theses & Dissertations

The purpose of the presented research is to study the convergence characteristics of Hopfield network dynamics. The relation between constraint weight parameter values and the stability of solutions of constraint satisfaction and optimization problems mapped to Hopfield networks is investigated. A theoretical development relating constraint weight parameter values to solution stability is presented. The dependency of solution stability on constraint weight parameter values is shown employing an abstract optimization problem. A theorem defining bounds on the constraint weight parameter magnitudes for solution stability of constraint satisfaction and optimization problems is proved. Simulation analysis on a set of optimization and constraint …