Engineering Commons^™

Structural Behavior Of Cold-Formed Steel Beam Webs Subjected To Partial Edge Loading, Shin-Hua Lin

Masters Theses

"An extensive experimental investigation has been conducted to study the load-carrying capacity of cold-formed steel web elements subjected to partial edge loading which may cause web crippling or web buckling. In this experimental work emphasis was concentrated on the cold-formed steel structural members having single unreinforced webs with stiffened flanges.

In 1980, American Iron and Steel Institute (AISI) revised its "Specification for the Design of Cold-Formed Steel Structural Members.” For the design of beam webs, Section 3.5.1 of the AISI Specification provides the design criteria for web crippling. This thesis discusses the experimental work including some specimens with small length-to-depth …

Ion Implantation For Improvement Of Wear Properties Of Steels, Kenneth W. Burris

Masters Theses

"Previous research on ion implantation at U.M.R. has dealt with the development of a modified Falex Lubricant Tester as a valid wear test and its use in dose curve determination. Our recent work uses Auger surface analysis and scanning electron microscopy to gather support for a model that will tie together some of the many theories proposed as to why ion-implantation improves the surface related mechanical properties of steels"--Abstract, page ii.

Real Time Interactive Graphics Systems Identification, Youcef Hammada

Masters Theses

“This thesis describes the implementation of an identification procedure as a package of graphic programs. This package of graphic programs will allow the user to perform a least squares parameter estimation, a recursive least squares parameter estimation, and a maximum likelihood parameter estimation of a linear second-order transfer function model. This model describes in a linear form the dynamic response of an automobile in a field operating environment.

The model is to reasonably reproduce the physical behavior of an automobile through two of its dynamic variables. These are the yaw rate as output and wheel angle as input. The model …

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 …

The Effect Of Selected Alloying Elements On The Hardness And Microstructure Of Ductile Cast Iron, Chi-Hua Edward Tseng

Masters Theses

The effects of cooling rate and alloying element on the matrix structure, nodule count and hardness have been studied in this investigation.

Recommendations for producing ferritic ductile iron have been made and the relationship between hardness and pearlite percentage has been obtained in this study.

Development Of Glass Microspheres For Radiotherapeutic Applications, Thomas A. Wetteroth

Masters Theses

"Oxide glasses make excellent candidates for radiotherapeutic microspheres used in liver cancer treatment because of their generally high chemical durability and safety of manufacture. From the compositions containing ~5 wt% P₂O₅ studied, magnesium alumino silicate glass microspheres and magnesium alkali silicate glass microspheres with 4 wt% ZrO₂ had acceptably low releases of both elemental phosphorus in deionized water at 50°C, and radioactive ³²P in human blood plasma at 37°C. The relative ranking of glass compositions in the elemental phosphorus leach test shows good agreement with the rankings of compositions in the radioactive ³²P leach …

Analyzing And Predicting Natural Circulation In A Snupps's Pwr Using "Retran-01", Roger Lee Boyer

Masters Theses

"The purpose of this project is to predict the natural circulation start-up test for the Standardized Nuclear Unit Power Plant System (SNUPPS). In order to make this prediction, a best-estimate, thermal-hydraulic computer code called RETRAN-01 is used.

The start-up test procedures require the simultaneous tripping of all four reactor coolant pumps (RCPs). Natural circulation is confirmed when the three test acceptance criteria have been met. Since this transient is symmetrical, a one-loop approximation of the Nuclear Steam Supply System (NSSS) is normally considered adequate in the nuclear industry. However, there is a concern over how to model the four actual …

A Technique For Obtaining Very Efficient Dynamical Equations For On-Line Computation Of Joint Forces Of Robotic Mechanisms, Dennis A. Dohogne

Masters Theses

"In order to increase the operational speed and positional accuracy of robotic mechanisms, on-line force control has been proposed. Because of the complexity of exact dynamical formulations, real-time computation of joint forces may be too slow.

Since force control is accomplished with a dedicated computer, unique, dedicated sets of force equations are justified. An efficient force computation technique based on the algebraic expansion and recombination of exact dynamics formulations is presented. Developments of the robotics matrix notation and of a Lagrangian dynamics formulation are also presented. A generalized three link manipulator model is used to compare the computational complexities of …

Separation Of Mineral Particles In Cyclones Under The Influence Of A Magnetic Field, Kwasi Amoako-Gyampah

Masters Theses

"The separation of mineral particles in a cyclone under the influence of a magnetic field was investigated using an electromagnetic - cyclone arrangement. Feed pulps of dolomite and magnetite were used in the study. Two different cyclone types were investigated: An air-type cyclone arrangement and a conventional cyclone arrangement. Magnetic field strengths of 0 to 3000 gauss (0 - 0.3 Tesla) were used in the study by varying the current through the coils of the electromagnet .

The parameters evaluated in the study were the grades and recoveries of the magnetic concentrates produced, the enrichment ratios, the improvement in recoveries …

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 …

Glass Formation And Properties In The Gallia-Calcia System, Glenn Whichard

Masters Theses

“The critical cooling rate for glass formation for melts containing from 37.5 to 68.0 mol % Ga₂O₃ varied from 310 ± 80°C/s to 855 ± 115°C/s. The crystallization temperature, microhardness, UV and visible transmission were measured. The density increased from 4.075 g/cm³ at 37.5 3 mol % Ga₂O₃ to 4.402 g/cm³ at 56.0 mol % Ga₂O₃. The refractive index, n_D, increased from 1.778 at 37.5 mol % Ga₂O₃ to 1.802 at 62.0 mol % Ga₂O₃. The IR spectra indicate …

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 …

Sintering Of Lif-Fluxed Srtio₃, Marie-Christine P. Proudian

Masters Theses

"Lithium fluoride (LiF) is used to enhance the sinterability of perovskites, as it results in the formation of a liquid phase. In this study, the mechanism and kinetics of sintering for LiF-fluxed strontium titanate (SrTiO₃) were investigated. The Sr/Ti ratio was varied between 0.98 and 1.03, and the LiF content in the green compact ranged from 0.5 to 2.0 weight percent. Sintering was conducted at temperatures between 695° and 925°C for isothermal dilatometric shrinkage measurements for time intervals of 6000 seconds or less. Weight loss, shrinkage, density and porosity measurements were conducted on samples isothermally sintered between 690° …

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 …

Closed Water Systems On Paper And Board Machines Using The Dysco Simulation Program, Stephen Robert Tremont

Masters Theses

This study was conducted to determine the accuracy of the DYSCO simulation program in simulating the open and closed water system on the pilot fourdrinier paper machine located in the Department of Paper Science and Engineering at Western Michigan University. The pilot machine was run at a maximum speed of 76 meters (250 feet) per minute without the press and drier sections, as well as slower speeds of 61 and 46 meters per minute. Retention data were obtained for fiber, titanium dioxide, and water at the three speeds. Upon entering these data along with stream inputs into the DYSCO simulator, …

A Control Program And Operating System For A Three Joint Robot Arm On An Apple Microcomputer, Eric Henry Stelzer

Masters Theses

"A Robotics Operating and Control System for a three-joint robot arm model is presented. The general operation of the system in interfacing the robot to the operator is discussed. Kinematic equations for the robot are derived and commands available to the operator are covered in some detail. The operation of the Control System in moving the robot is explained. Finally, suggestions are made for further development of the system"--Abstract, page ii.

A Single Cylinder Engine Study Of Lean Supercharged Operation For Spark Ignition Engines, Kenneth Robert Schmid

Masters Theses

"A comprehensive single cylinder engine test program to evaluate Lean Supercharged Operation (LSO) for spark ignition engines was conducted. The evaluation involved an experimental program studying the power, emissions, and efficiency of a single cylinder engine. The relationships between engine power, efficiency, and emissions and the engine operating variables such as absolute intake manifold pressure, Exhaust Gas Recirculation rates, and spark timing were studied"--Abstract, page ii.

An Applied Approach To Automatic Pressure Transient Analysis., Jeffrey Allan Joseph

Masters Theses

"A generalized digital approach to pressure transient (well-test) analysis is developed. The model is rigorously applicable to flow tests (pressure drawdown or injectivity of Newtonian liquids), and to pressure buildup or falloff tests provided the f low time prior to shut-in is large compared to the total shut-in time. However, buildup or falloff data may s till be analyzed if the above conditions are not satisfied, using the principles of superposition/desuperposition.

When plotted on logarithmic coordinates, pressure transient data generally assume a characteristic shape, indicative of flow behavior. Accurate computer analysis of this data requires its representation in concise mathematical …

Drawing Characteristics Of Electrogalvanized Steel Wires., Chi-Yuan Tsao

Masters Theses

"As a means of investigating the often adverse drawing behavior of electrogalvanized steel wire, drawing experiments were conducted on a variety of industrially-supplied and laboratory-prepared electroplated steel wires. Back-flow and shaving appeared to be the mechanisms by which sizeable zinc losses occurred. Performance during drawing and the quality of the product depended upon both the characteristics of the plating and the drawing process variables. Grain size, grain texture, and surface 'flatness' can affect the required drawing force, surface finish and level of zinc retention. Low die angles and large reductions offered greatest efficiencies with minimum zinc loss"--Abstract p. ii

Sessile Drop Studies Of Gallium On Alumina, Timothy John Snyder

Masters Theses

"The liquid-vapor and solid-vapor interfacial energies of the system Ga-Al₂O₃ were determined by the sessile drop technique. The interfacial energies were found to decrease with increasing temperature and P₀₂.

A maximum liquid-vapor interfacial energy of 581 ergs/cm² was found for a clean sessile drop at 1227°C. Values for Γ₀, the excess concentration of oxygen, were calculated for both the liquid-vapor and solid-liquid interfaces. The work of adhesion between molten Ga and Al₂O₃ was found to increase with decreasing P₀₂ with a maximum of 576 ergs/cm² occurring …

The Influence Of Manganese Oxide On Sintering Of A Commercial Natural Magnesite., Alamar Kasan Duarte

Masters Theses

"Sintering studies on a commercial natural magnesite have been done to investigate the influence of MnO doping (MnO concentration from 0.16 to 2.50 wt.%) on the densification process over the temperature range 1520 to 1760°C , over periods of time from 3,600 to 57,600s in both oxidizing and reducing atmospheres (Air and P_O2 = 10^-7 KPa. In an air atmosphere the additions of MnO enhances the densification process. This fact may be associated with an increase in lattice diffusion of Mg ions due to an increase in cation vacancies in the MgO lattice from the presence of …

Aerodynamics Of Closely Coupled Wings For Varying Chords And Airfoil Planforms, Gary D. Vincent

Masters Theses

"Aerodynamic characteristics of a dual wing aircraft were analyzed with variations in airfoil sections and chord ratios over existing equal chard ratio dual wing and monoplane aircraft designs. Two- and three-dimensional aerodynamic studies were conducted to find the wing geometry which would create the minimum cruise drag. The two-dimensional aerodynamic data was obtained from a multi-element inviscid vortex panel program coupled to a momentum integral boundary layer program to account for the aerodynamic coupling between the wings. With this data, a three-dimensional vortex lattice program calculated the three-dimensional aerodynamic data. compared to an equal chard ratio dual wing aircraft, lower …

A Determination Of The Energy Storage Capacity Of The Diels-Alder Reaction Between Methylfuran And Maleic Anhydride As Applied To Storing Solar Energy, Brent Gregory Sparks

Masters Theses

“The heat storage capacity of the Diels-Alder reaction between 2-methylfuran and maleic anhydride is calculated using reaction parameters obtained from solution calorimetry. An equilibrium constant of .614 1/mol and a heat of reaction of 14.33 Kcal/mole were obtained from experiments at 45°C. A reaction ΔC_p of -21.8 cal/mole was calculated from heat capacity information at 25°C. From these parameters, a solution initially seven molar in methylfuran and maleic anhydride was found to have a maximum apparent volumetric heat capacity of about 1.85 times that of water. This maximum occurs at about 335 K. Typical active solar energy schemes operate …

A Model For Optimization Of The Archer's Compound Bow., Mark Aaron Kincy

Masters Theses

"The object of this work is to establish an analysis procedure to permit optimization of the design of ti1e compound bow. The distinguishing features of the compound bow are a system of cables and eccentric pulleys which change the leverage between the bow string and the bow limbs as the string is drawn. This approach concentrates on an accurate representation of the limb mechanics which will allow the design of eccentric wheels to improve the energy storage potential of the bow and thereby increases the velocity of an arrow cast by the bow.

The compound bow is a rather unique …

Transverse Thermal Response Of A Composite Bridge, Michael J. Filla

Masters Theses

"A two-span, composite-design, test structure was subjected to thermal loading. The resultant longitudinal and transverse response was correlated with that calculated by a prior theoretical procedure. The theoretical procedure was reconfirmed for longitudinal stress, and indicated within reasonable probability for transverse stress. No measurable diaphragm influence was observed"--Abstract, page iii.