Digital Commons Network^™

Optimizing Transformer Impedance For Short Circuit Analysis, Louis Scott Becker

Masters Theses

"Transformer impedances change when the tap positions on the primary or secondary are changed. Models were designed that gave the maximum impedance variation for a large percentage of transformers studied. These models were used to study how fault currents deviated from the predicted values if the actual transformer impedance was not the same as the predicted impedance. The effects of the change in turns ratio was also taken into account, and the base voltages were chosen to be different from the transformer voltages to include this possible error.

Faults were placed on the secondary of a model radial power system, …

Intensity Blending Of Computer Image Generation-Based Displays, Elizabeth Scheppler Reidelberger

Masters Theses

"State-of-the-art combat simulators require a 360 degree field of view, allowing the pilot and radar intercept officer to have the same visibility in the simulator that they would experience in the aircraft. The sky/earth display must be computer - generated and displayed with a minimum of two channels to provide the most realistic display possible. The two channels of display come together in the dome, forming an equator, that must be as indiscernible to the aircrew as possible. To accomplish this, an algorithm has been developed for controlling the video output which makes the two separate channel displays appear as …

Computer Control Of A Pbx Washout Plant, Scott Cameron Sharp

Masters Theses

"A fully automated, computer controlled plant has been designed specifically for safe removal of plastic bonded explosives (PBX) from obsolete military munitions. This PBX washout plant consists of a two stage delivery system and robotically operated high pressure waterjet lance. The assigned task was to develop control packages for each component.

The first stage of the delivery system is a battery operated overhead trolley. Its control package consist of a dedicated computer, DC motor and custom positioning subprograms. The dedicated computer communicates through an infrared link to the operator's computer. This link was developed due to requirements of a hazardous …

Behavior Of Reinforced Loess Specimens Under Triaxial Load, Mohammad Taghi Izadi

Masters Theses

"Effects of reinforcement on shear strength of a loessial (silty) soil arc studied. Unconsolidated undrained triaxial tests are performed on unreinforced and fabric reinforced soil specimens. Analyses of the test results showed that in general the shear strength of remolded loess specimens were improved substantially and increase in the shear strength was directly related to reinforcement spacing.

The mechanism of soil-reinforcement interaction and several existing analytical models are described. A modified analytical model based on enhanced confining theory is developed. This model can be used in assessing the effects of the reinforcement on shear strength of triaxial specimens. Comparison of …

Vle For 1,3-Butadiene With 1,2-Butadiene And Propyne, Patrick J. Gripka

Masters Theses

"Vapor pressures for pure 1,3-butadiene, 1,2-butadiene and propyne and 10 binary mixtures are reported at 5, 20, 35, 50, and 65°C. An equation of state utilizing saturated vapor and liquid densities is used to correlate the experimental data. Calculated relative volatilities and saturated densities are reported for the systems 1,3-butadiene - 1,2-butadiene and 1,3-butadiene - propyne. The thermodynamic excess functions Helmholtz free energy, Gibbs free energy, entropy, enthalpy, internal energy, volume, and heat capacity are derived for the equation of state and the excess properties are reported for the two systems"--Abstract, p. iv.

The Effect Of Phosphate Additives On Alumina, Alumina-Calcia, Alumina-Silica Refractory Castable Systems, Sukendro Widjaja

Masters Theses

The effects of the addition of phosphate chemicals to Al₂O₃, Al₂O₃-CaO, and Al₂O₃-SiO₂ systems have been studied concentrating on selected dry and fired properties. The various refractories evaluated were formulated from all alumina aggregate systems based on 1) a mix of tabular and calcined fine aluminas, 2) a combination of calcium aluminate cement bonded-tabular and calcined fine aluminas, and 3) an alumina aggregate-silica fume mixture. Specimens were vibration-cast, dried at 110°C and fired at 1450°C. It was found that each system has different property responses to different …

Sessile Drop Studies Of Aluminum On Sapphire, Ke Wen K. Li

Masters Theses

A sessile drop technique employing a drop placement method has been used to investigate the wetting behavior and interfacial phenomena between aluminum and single crystal α-alumina. Measurements were made under a flowing mixture of H₂ and He atomsphere from 1200°C to 1600°C. Acute contact angles decreased continuously in all cases during the 8-hour experimental time. Neither the oxygen partial pressure of the flowing gas nor the orientation of the single crystal alumina substrate affected the contact angles, but the shapes of crystals grown at the substrate-metal interfaces were dependent on the orientation of the substrate surface to some extent. …

An Experimental Study Of Adsorption And Variable Temperature Desorption Of Ethanol-Water, Propane-Propylene And Hydrogen Sulfide-Carbon Dioxide-Propane, Suvit Kulvaranon

Masters Theses

"An ideal adsorption only removes the desired components. Many times one or more other components are also adsorbed. If two or more components are adsorbed, an adsorption separation may not be satisfactory or may require additional separation procedures, even though one is highly preferentially adsorbed. In such cases it may be possible to get additional separation during the desorption stage by using variable temperature desorption.

To study such problems, two experimental apparatus were set up, one for adsorption for ethanol and water mixtures on activated carbon and silicalite, the other for propane-propylene mixtures, and hydrogen sulfide-carbon dioxide-propane mixtures both on …

Fabrication And Mechanical Property Analysis Of A Transparent, Glass Fiber Reinforced Polymer Matrix Composite, James R. Olson

Masters Theses

"A "transparent” composite was produced by reinforcing poly(methyl methacrylate) (PMMA) with unidirectional borosilicate glass fibers. Composites with 40 volume percent fiber had a modulus of rupture of 600 MPa which is six times greater than that of pure PMMA. Young's modulus for the same composite was 18 MPA which is nine times greater than the 2 MPa measured for pure PMMA. Work of fracture was 110 kJ/m² or more than double the 45 kJ/m² required to fracture pure PMMA. The optical transmission of the composite with 30 volume percent fiber was approximately 40 percent through a 10 mm …

A Three-Dimensional Bistatic Radar Target Position Measurement Error Model, Robert Kenneth Lynn

Masters Theses

"The accuracy of target position measurements for an airborne bistatic radar receiver are calculated. Two methods of information measurement are utilized, both of which assume cooperative synchronization between the transmitter and receiver. Gimbal angle errors are incorporated into both methods. The size and orientation of the error ellipsoid about the true target position is found. Loci of constant circular error probable are plotted in a horizontal plane of interest"--Abstract, page ii.

The Effect Of Additives On Properties Of Pfn-Pfw Dielectric Materials, Weih-Min Liao

Masters Theses

"The purpose of this study was to investigate the effect of processing and additives on the properties of the Pb(Fe_1/2Nb_1/2)O₃-PB(Fe_2/3W_1/3)O₃ solid solutions. The basic composition was 70 m% Pb(Fe_1/2Nb_1/2)O₃ and 30 m% Pb(Fe_2/3W_1/3)O₃. The additives used were MnO, PbO and ZnNbO₆. Pressed compacts were sintered over the temperature range 900'C to 1050°C for 1 to 5 hours.

The influence of processing and composition on the properties was determined by measurement of density, shrinkage, dielectric constant, dissipation factor and …

Reductive Stripping Of Iron(Iii) From Di(2-Ethylhexyl) Phosphoric Acid, Byron G. Belew

Masters Theses

"Unwanted impurities, present in raw materials, are often coextracted along with desired constituents during leaching. If left unchecked, impurity levels may increase in hydrometallurgical process streams until their presence has deleterious effects upon subsequent unit processes. Due to its abundance and ease of extraction, the presence of ferric iron in solvent extraction circuits has always been a problem. The technique proposed herein constitutes a novel approach to remove iron from zinc hydrometallurgical circuits; but the principles employed may find a variety of applications.

This research investigated the reduction and stripping of ferric iron from di(2-ethylhexyl) phosphoric acid into a …

A Parallel Implementation Of Stickel's Ac Unification Algorithm In A Message-Passing Environment, David John Kleikamp

Masters Theses

"Unification algorithms are an essential component of automated reasoning and term rewriting systems. Unification finds a set of substitutions or unifiers that, when applied to variables in two or more terms, make those terms identical or equivalent. Most systems use Robinson's unification algorithm or some variant of it. However, terms containing functions exhibiting properties such as associativity and commutativity may be made equivalent without appearing identical. Systems employing Robinson's unification algorithm must use some mechanism separate from the unification algorithm to reason with such functions. Often this is done by incorporating the properties into a rule base and generating equivalent …

Attitudes Of Teachers And Teacher Trainees Towards Faculty Unionization, Caroline M. Rodriguez

Masters Theses

No abstract provided.

Gifted Underachievers, Jean A. Walters

Masters Theses

No abstract provided.

The Influence Of Male-Female Relationships On The Self-Development Of Maya Angelou, Susanne Bartsch

Masters Theses

No abstract provided.

Suppression, Repression, And Expression: Black Anger In Huckleberry Finn, Pudd'nhead Wilson, And The Marrow Of Tradition, Tammy F. Veach

Masters Theses

No abstract provided.

Habitat Analysis And Foods Of Shrews In East Central Illinois, Lisa D. Blackburn

Masters Theses

No abstract provided.

A Study Of Adult Students Enrolled In Off-Campus Classes, Margaret A. Schrock

Masters Theses

No abstract provided.

Callus Formation And Differentiation In Embryos Of The Coconut Palm (Cocos Nucifera L.), Jyoti Mangesh Desai

Masters Theses

Embryos of Cocos nucifera L. were allowed to develop on various agar based, plant tissue culture media. Environmental conditions, temperature, light intensity levels and photoperiod were regulated throughout the period of the experiment. The anatomy of commercially available embryos (excised from the "seed") and tissues that developed in culture (calli, roots and leaves) was determined. Prepared slides and tissues obtained in culture were photographed and printed. Callus, root and shoot formation were successful. However, "embryoids" which would have eventually led to free living plantlets were not obtained during this study. Successful regeneration of plantlets in culture would require improved techniques.

Coal Desulfurization Using Pyrite Conversion Through Dielectric Heating, Daniel C. Cleaveland

Masters Theses

The Illinois State Geological Survey is currently developing a three step coal desulfurization process which depends upon the in-situ generation of catalytic troilite (FeS) by reduction of the pyrite (FeS₂) present in the mineral fraction of coal. After catalyst generation, ethanol is added to the system and is dehydrogenated to acetaldehyde and hydrogen which removes organic sulfur as hydrogen sulfide. The research reported in this thesis shows that the process can be improved by the use of dielectric heating in place of thermal heating for catalyst generation and perhaps organic sulfur removal. It is found that pyrite reduction …

Effect Of Event (Acp 1911) On Rough Turf Grasses At Coles County Airport, Illinois, Phena Khanjila Shimaka

Masters Theses

Event is a plant growth regulator that was applied to rough turfgrass at Coles County Airport, Charleston-Mattoon at rates of 0, 8, 10 and 12 ounces per acre. Each of the 12 plots was divided into three sections "mowed", "mowed once" and "unmowed" at application time. The mowed portion was sampled at two week intervals for a six week period and biomass recorded in grams dry weight. Prior to mowing, all the plots were visually observed for broadleaf weeds control, height and seedhead suppression, discolouration and phytotoxicity.

The 12 ounces rate of Event significantly suppressed seedhead production, height, broadleaf weeds …

Characterization Of The Lipopolysaccharides From Rhizobium Phaseoli Symbiotic Mutants, Francisca Garcia

Masters Theses

The lipopolysaccharides (LPSs) of the Rhizobium phaseoli CE3 and its mutants CE109, CE309 and the transconjugate Rhizobium leguminosarum LB2/109.11 were isolated and analyzed by gas chromatography (GC) and ¹H nuclear magnetic resonance (NMR) spectroscopy. CE3 is the wild type strain which is nodulation-proficient (Nod⁺). Strain CE109 and CE309 have a transposon, Tn5, inserted into Region I and Region III of their respetive chromosomes. Mutants CE109 and CE309 are defective in nodule development (Ndv^-). Transconjugate R. leg. LB2/109.11 has the DNA of the R. leg. LB2 wild type and also Region I portion of the CE109 …

Creating A Model For A Student Assistance Program For High School Students Involved In Substance Abuse, George C. Lewis

Masters Theses

Substance abuse is a problem faced by schools, parents, students and communities. The purpose of this field experience was to provide a plan to help educators, parents, students and communities deal effectively with youth involved in substance abuse. The need for this field study became evident to the researcher when twenty-five students from the student body of Salem Community High School were placed in in-patient substance abuse programs during the 1985-86 school year.

The literature was examined and certain reactions and trends indicated in the literature were identified. Many substance abuse programs were reviewed. Key programs reviewed include the following: …

The Effects Of The Structured Listening Activity Model On The Listening Comprehension Of Second Grade Students, Angela M. Flach

Masters Theses

The investigation was designed to assess growth in listening comprehension after participation in the Structured Listening Activity (SLA) model for improving listening comprehension.

Prior to treatment, two experimental groups and one control group were administered the Science Research Associates' (SRA) Survey of Basic Skills, Level 21, Listening Comprehension Subtest to assess listening comprehension abilities.

Slx SLA model lessons were designed and administered twice a week for twenty minutes over a three week period. SLA model lessons follow five sequential steps: concept building, listening purpose, reading or telling a passage, questioning, and recitation.

SRA’s Survey of Basic Skills, Level 21, Listening …

Acquired Immune Deficiency Syndrome Policies In Central Illinois: A Survey, Analysis, And Model, Daniel Lathrop

Masters Theses

One purpose of this study was to develop model policies for school districts to use in dealing with Acquired Immune Deficiency Syndrome (AIDS). A second purpose was to identify which school districts in the Educational Service Region (ESR) comprised of Clark, Coles, Cumberland, Edgar, Moultrie, and Shelby counties had addressed the issue of AIDS policies. The population surveyed in the initial phase consisted of 22 superintendents within the ESR. A survey was developed utilizing many items from a national study (Keough and Seaton, 1987). The survey was administered during a monthly meeting of superintendents hosted by Regional Superintendent Rosemary Shepherd. …

The Effect Of Strikes On Superintendents, Marilyn J. Yokel

Masters Theses

The purpose of this study was to investigate the perceptions of public school superintendents regarding teacher organizations, negotiations, personnel and influence, progression of events related to the strike, issues that contributed to the strike, and time spent working on strike-related activities during and after Illinois teacher strikes occurring during the 1986-87 school year. A review of the literature revealed much relevant advisory information, but this literature was limited to one aspect or another of a strike situation, for example negotiations or unions. The Superintendent Questionnaire was sent to school districts where teachers struck during the 1986-87 school year. Descriptive statistics, …

A Model For Small Illinois School Districts In Response To Financial Crisis, Michael A. Weaver

Masters Theses

This study describes the options available to small, rural Illinois school districts that face financial crises. The implications for a particular school relative to consolidation, annexation, cooperative high schools, tuitioning out, and tax referenda are described. Survey results relative to school effectiveness, the financial future, and school loyalty are reported and analyzed. The study concludes with a recommendation which appears most appropriate to solve the financial problems of the Findlay Community Unit School District #2.

The Effect Of Collaborative Consultation Between The Regular Educator And The Special Educator On The Achievement Of Students Labelled Learning Disabled In The Mainstream, Lisa Ann Dewitt

Masters Theses

The effect of consultation on student achievement is an area in which much research is currently needed. This study addressed the issue of how collaborative consultation between regular and special educators effected student achievement. The study utilized a multiple baseline design across subjects to determine the effectiveness of the consultation program. The two-phased study (baseline and consultation) occurred over an eight week period in two third grade and one fourth grade classrooms.

The study involved three regular classrom teachers, one special educator and three students who were labelled learning disabled and who were mainstreamed into the regular classroom. The regular …

Lincoln And Oregon, Todd Hageman

Masters Theses

The Civil War is one of the most significant events in American history. President Abraham Lincoln’s term in office was dominated by the War, therefore the study of Lincoln has likewise been dominated by War developments. The War’s battles were overwhelmingly concentrated in the eastern United States, and hence the American west has largely been ignored by Lincoln scholars. This study attempts to uncover Lincoln’s policy toward Oregon, including War developments and his domestic policy, to partially fill the “western gap” in Lincoln scholarship.

Oregon was admitted to the federal Union in 1859, and by Lincoln’s election in 1860 that …