Engineering Commons^™

Solar Air Heaters For On-Farm Crop Drying: Case Studies, Alvin Ray Womac

Masters Theses

Three types of suspended plate solar air heaters were installed on farms in Tennessee to supply heat for grain and crop drying. A wrap-around solar air heater was constructed on a row crop farm in West Tennessee and used to dry 210 m³ (6000 bu) of corn during Fall 1982 and 105 m³ (3000 bu) of wheat during Spring 1983. Three portable solar air heaters were installed on a row crop farm in Middle Tennessee and used to dry 800 m³ (23000 bu) of soybeans and 120 m³ (3500 bu) of corn during Fall 1982. A …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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° …

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 …

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.

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 …

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.