Engineering Commons^™

A Model Of The Bromine/Bromide Electrode Reaction At A Rotating Disk Electrode, Ralph E. White, S. E. Lorimer

Faculty Publications

A mathematical model is presented for the Br₂/Br^– electrode reaction at a rotating disk electrode. The model includes current density-overpotential expressions for the electrode reaction according to either the Volmer-Heyrovsky (V-H) or the Volmer-Tafel (V-T) mechanism and the transport equations including the effect of ionic migration. The model is used to predict current-overpotential curves for various cases of interest. Qualitative comparison of the model predictions to literature data shows that either the V-H or the V-T mechanism, with V controlling, may be acceptable for the Br₂/Br^– reaction.

Low Cost Neutron Detector, Sebastian K. Namukolo

Retrospective Theses and Dissertations

Neutron bombardment of bipolar transistors creates cluster defects in semiconductor material. The clusters are small volumes of semiconductor material containing several hundred atoms displaced from their proper lattice sites owing to collision processes. They act as recombination centers in transistor bases, reducing minority carrier lifetime and consequently reducing transistor current gain. The damage is permanent to the semiconductor device and can only be corrected by thermally annealing the transistor. Copious test data available on bipolar transistors d.c. gain (h_FE) response to incident fast neutron fluences confirm their mathematically derivable functional relationships. This report develops a neutron fluence detector …

Modal Analysis By State Space Approach In Frequency Domain, Feliciano Feijo

Retrospective Theses and Dissertations

This report tests a new procedure to identify the eigenvalue problem matrix "A" by utilizing the frequency response of a system in state-space for a given sinusoidal forcing input. Two sample identification tests are performed and a detailed explanation of both cases is presented. The method proved to be correct and the results obtained were accurate in both cases. A random error was then added to both sample tests in order to simulate real measuring conditions. Results indicate that it is more difficult to identify the "A" matrix of an undamped system. The error in the system must be very …

Simulation Of Naval Student Flow Using Pipeline Management Model, Mary L. Sankey

Retrospective Theses and Dissertations

The U.S. Navy's training system is an extensive, complex system of interrelated and interacting components. This paper presents the results of several approaches to the problem of modeling this system and developing computer programs to simulate and analyze its operation. Two programs using special-purpose simulation languages, SLAM and GASP, are described briefly. The PMM inter-active system is described and analyzed in the greatest detail. Possible future utilization of this PMM system for experimentation and forecasting is also briefly discussed.

The Technical And Economic Feasibility Of Producing Methane From Biomass Using A Leaching-Bed/Packed-Bed Conversion Process, Steven W. Hinton

Retrospective Theses and Dissertations

The economic feasibility and energy effectiveness of producing pipeline quality methane gas from biomass was assessed for a new and totally unproven process. The biomass feedstock considered was the common aquatic weed water hyacinth and a novel active boom-winch harvesting system is proposed for its collection. The conversion process analyzed is a two stage biological process which utilizes a leaching-bed for the production of volatile acids and a packed-bed for the production of methane gas. In order to determine the feasibility of the proposed process equipment requirements, capital costs and operating/maintenance costs were developed for three system sizes. This data …

Digital Communications System Evaluation: Design Developments In Pseudorandom Sequence Usage, Signal Conditioning And Timing Regeneration, Barry Lane

Retrospective Theses and Dissertations

The aim of this paper is to develop a series of designs which allow evaluation of several digital communication system design concepts. Circuits were developed and tested which deal with three central areas of concern in digital communication networks. They include random signal generation and detection, signal conditioning, and digital timing extraction. A pseudorandom sequence generator and correlator design form the basic digital channel. Bi-phase transmission coding and digital timing regeneration were later added to the initial channel. System performance was confirmed by inserting errors and measuring error rate.

Flow Tube Reactions Of Selected Chlorocarbons With Molecular Hydrogen Or Water Vapor In A Microwave Induced Plasma Reactor, Robert Benedict Barat

Theses

The reactions of various chlorinated hydrocarbons with molecular hydrogen or water vapor have been studied in a microwave plasma tubular flow reactor. The investigation of such reactions is desirable because the often toxic parent chlorocarbons are transformed to more thermodynamically stable and relatively non-toxic products by removal of' chlorine atoms as hydrogen chloride. Present detoxification technologies generally employ thermal oxidation as a means of disposal of chlorocarbons, which does not offer a thermodynamically stable sink for the chlorine atoms.

The experimental apparatus included feed introduction systems, a microwave plasma reactor, and full product analyses. The feed systems enabled use of …

Spacially Sampled Multi-Aperture Optical System For Robot Vision, Ali R. Baradar

Retrospective Theses and Dissertations

One of the solutions to the world's industrial and economic recovery and survivability is "Flexible Automation," wherein vision is the key to its cost-effective flexibility. Vision gives the robot a measure of environmental intelligence. The majority of present vision systems are patterned after the human eye, but this is not a requirement. It has been shown that the multi-aperture insect eye cannot image an object. The physiology of an insect eye is fundamentally different than that of the human eye in that it is not binocular by multioccular in nature. In order to study multi-aperture optics and indirectly the functioning …

The Effects Of Impoundments On Salinity In The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

The increase in salinity of our western rivers has been identified as one of the most serious water quality problems in the nation. This is of special concern in the Colorado River where salinity has increased from pristine levels estimated at 380 mg/1 to present-day levels of 825 mg/1 at Imperial Dam. Flow depletions, associated with decreased runoff and increased evaporation and diversions, coupled with high salt loading from natural and man-created sources are considered the primary causes for rising salinity in the river. The urban and agricultural development projected to occur in the basin through this century could deplete …

Electrical Engineering, C. J. Thomforde

UND Departmental Histories

This departmental history was written on the occasion of the UND Centennial in 1983.

Investigation Of Important Surface Characteristics Of A Finned Tube Heat Exchanger, Bobby Dale Stafford

Masters Theses

"Surface characteristics of a finned tube heat exchanger were examined to help predict the contact geometry between metal surfaces. These characteristics were the surface roughness and waviness and the material hardness. A scanning electron microscope was used to observe the surface topography of the fins as well as examining the contact between the aluminum fin and the copper tube.

Comparisons of the surface roughness were then made between heat exchangers having different fin numbers (20, 14, and 6) with the result that as the fin number decreased, the roughness also decreased. For a given fin number, it was discovered that …

Mechanical Properties Of High Strength Sheet Steels, M. Brad Parks

Masters Theses

"In recent years fuel economy has become one of the major criteria for the design of automobiles. In order to improve the efficiency of their vehicles many automotive designers are substituting high strength sheet steels for traditional materials of lower strength. This thesis discusses experimental work which was done to determine the representative mechanical properties and stress-strain relationships of a select group of high strength sheet steels with nominal yield strengths ranging from 80 to 140 ksi. The results show that high strength sheet steels are quite anisotropic with the variation in measured properties depending on the type of sheet …

Contouring And Analysis Of Rock Hardness And Point Load Strength Index Values For The Bethany Falls, Winterset, And Argentine Limestones In The Greater Kansas City Area, John Robert Cramer

Masters Theses

"A field study was conducted to evaluate the variations in selected physical properties of the Bethany Falls, Winterset and Argentine Limestones in the Greater Kansas City Area. On-site and laboratory testings of these rocks for hardness and strength were made. Data from the different sites were contoured to graphically illustrate changes in the rock properties geographically. Results of this study are presented with the hope that they may be useful preliminary information for rock excavation engineers working in the area.

The area covered by the study included Platte, Clay, Johnson, and Cass counties in Missouri, and Leavenworth, Wyandotte and Johnson …

Control Of Rock Fragmentation Through Explosive Coupling, Timothy Wayne Warden

Masters Theses

"Both detonation pressure and borehole pressure, resulting from an explosion within blastholes in rock, perform specific functions in the fragmentation of the rock and the generation of ground vibrations. The results of previous investigations would suggest that control of these pressures in the borehole would, to some extent, control the size distribution of the blasted particles. One method of influencing detonation and borehole pressures is by varying the hole diameter in relation to a constant charge diameter, called decoupling, and by varying the medium between the explosive charge and the rock.

This investigation examined the effects of geometric coupling, which …

Defect Chemistry Of La-Doped Strontium Titanate, Brian Keith Flandermeyer

Masters Theses

"Thermogravimetric measurements as a function of oxygen activity were performed in the temperature range of 1200°C to 1400°C on a series of La-doped SrTiO₃ compounds. A model postulating the crystallographic accommodation of ionic defects induced by the donor under oxidizing conditions is assumed. Thermodynamic calculations were performed to compare this model to the experimental results with reasonable success"--Abstract, page iii.

Microcomputer Control Of A Model Robot System Using Programmable Pulse Width Modulation, Richard Eugene Wainwright

Masters Theses

"The hardware design of a model robot system for experimentation in microcomputer control is presented. A special interface board is designed to allow an Apple II Plus microcomputer to control a model robot system which consists of a three-jointed robot with an electromagnet end effector and a conveyor belt, with an optional vision system. A programmable pulse-width modulator is designed to drive the DC motors which operate the robot and conveyor belt. Improvements and additional uses for the model system are discussed"--Abstract, page ii.

Mechanical Properties Of Alumina For Orthopedic Implant Use, Ho Tong Fang

Masters Theses

"The static fatigue, flexural strength and chemical corrosion of three commercially prepared, polycrystalline aluminas, two of orthopedic implant grade, were measured in demineralized water at 37°C and 70°C. The dissolution of a Ca-rich impurity phase, probably a glass, segregated at the grain boundaries and external surface, appears at least partially responsible for the significant difference in static fatigue of these three aluminas. The present results indicate that the minimum static fatigue in demineralized water, and the highest flexural strength in demineralized water and HF solution are both achieved by the alumina characterized by a low concentration of Ca at the …

Unifac Parameters For Maleic Anhydride And 2-Methyl Furan In P-Dioxane System, Kow-Jen Daumn

Masters Theses

"The purpose of this work was to develop a method for calculating equilibrium concentrations for reversible liquid phase reactions from a minimum of experimental data. The example reaction studied was the Diels Alder reaction between 2-methyl furan and maleic anhydride. Specifically, interaction parameters of the UNIFAC model for groups in the compounds 2-methyl furan, maleic anhydride and the solvent, p-dioxane, were determined. The activity coefficient of each substance was then predicted by the UNIFAC method. Equilibrium constants at 45°C for the Diels Alder reaction between 2-methyl furan and maleic anhydride were then calculated from these activity coefficients and two previously …

A Theoretical And Experimental Investigation Of Single Phase Flow Through A Small Centrifugal Pump In Three Quadrants Of Operation, Lee Charles Cadwallader

Masters Theses

"The operating characteristics of a conventional centrifugal pump have been investigated, both theoretically and experimentally, in three modes of operation with single phase liquid water at atmospheric pressure and room temperature.

Simple one-dimensional theory has been used to evaluate the theoretical pump performance, and these evaluations are compared to actual experimental data. The actual data shows the degradation effects of flow friction and shock losses that the theory does not take into account. The comparison of the curves illustrates these differences.

The data obtained compares well to and reinforces data from experiments found in the literature review.

Based on the …

Use Of Peats As Embankment Foundations : Interim Report, Harold Allen Gruen, C. W. Lovell

JTRP Technical Reports

No abstract provided.

An Investigation Of Contract Claims For Indiana Highway Construction Projects, Karen Denise Berg

JTRP Technical Reports

No abstract provided.

Priority Setting Of Highway Improvement Projects, Mark Douglas Harness, Kumares C. Sinha

JTRP Technical Reports

No abstract provided.

Design Of Compacted Clay Embankments For Improved Stability And Settlement Performance : Interim Report, Martin J. Goodman, Jean-Lou Chameau, C. W. Lovell

JTRP Technical Reports

No abstract provided.

Controlling Movement Of Embankments Over Peats And Marls, Harold Allen Gruen, C. W. Lovell

JTRP Technical Reports

No abstract provided.

Indiana State Highway Reciprocity Study, Kumares C. Sinha, Graham S. Toft, Virgil L. Anderson, Essam Abdel-Aziz Sharaf, Kang Hu

JTRP Technical Reports

No abstract provided.

1983 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Herpicc

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.

A Training Guide For Pavement Maintenance Personnel, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

These Guidelines have been prepared as a reference for highway maintenance personnel responsible for patching pavements and are intended as a reference for the patching crew. The Guidelines are not intended to be a detailed reference describing the successes and failures of techniques and materials used by various agencies to construct pavement patches. The patching techniques and materials presented in these Guidelines are those which have been developed by research and successfully used by various agencies to patch highway pavements under various climatic or weather conditions.

Checklist For Preparing Basic Motor Grader (29,000 Lbs. Class) Specifications, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This checklist provides various items to be considered when seeking bids for motor graders.

Effects Of Myocardial Infarction On Catheter Defibrillation Threshold, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Because the automatic implantable defibrillator may be used in patients having ischemic heart disease, it is important to know whether myocardial ischemia changes the threshold for ventricular defibrillation under experimental conditions simulating automatic internal defibrillation. We determined changes in ventricular defibrillation threshold following coronary occlusion, using an electrode catheter designed for use with an automatic implantable defibrillator. Acute myocardial ischemia was produced without thoracotomy in 10 dogs (experimental group) by embolization with a plastic bead injected via a catheter into the left coronary artery. A control group of 4 dogs had only saline injected into the artery. Defibrillation threshold was …

Simple Methods For Determining The Accuracy Of Tumor Blood Flow Measurements Using Radioactive Microspheres In Rats, Rosanna C. Chan, Charles F. Babbs, Richard J. Vetter

Weldon School of Biomedical Engineering Faculty Publications

Two simple methods are presented that allow positive identification of the accuracy and precision of the microsphere technique and a quick verification of sphere entrapment in tumor vessels. A known flow of Ringer's solution from a motor-driven syringe is perfused through the rat's isolated systemic circulation from left ventricle to right atrium and collected in a funnel. Using this preparation, total blood flow in rats measured with radioactive microspheres injected into the left ventricle was 97% of actual flow. The coefficient of variation (standard deviation/mean) of the microsphere measurements was 0.22. In the same preparation, non-entrapment of microspheres in subcutaneous …