Digital Commons Network^™

Square Wave Modulation, Richard Henry Duncan

Masters Theses

"Modulation of a radio frequency carrier can be defined as the variation of some wave parameter such as amplitude, frequency, or phase, in accordance with intelligence to be transmitted. An unmodulated carrier is simply a continuous sine wave and contains no information other than the fact that the transmitter has been turned on. The spectrum of an unmodulated signal consists of a single frequency. Any type of modulation is characterized by the appearance of additional frequencies, known as sidebands. One of the fundamental problems in radio engineering is to reduce the number of sidebands to a minimum and still adequately …

Investigation Of The Fundamental Properties Of Rubber-Asphalt Mixtures, Yali Cevat Hasan

Masters Theses

"The writer of this thesis believes that the most important thing next to the original construction cost of a road, is the maintenance cost. It is apparent that the maintenance cost for any given road is directly proportional to the percentage of worn out sections in that road. It is believed that climatic conditions are the very first cause of road failures and that traffic on the road often has a secondary degree of importance in the causing of road surface failures….

It is obvious that extreme heat as well as extreme cold will ruin a road. A heavy traffic …

A Study Of Volatility And Desulfurization Of Titanium Disulfide, Sheng-Tai Shih

Masters Theses

"The application of high vacuum for the promotion of metallurgical reactions is a comparatively new development. During the war the need for high vacuum in producing magnesium by the Pidgeon Process and in certain phases of uranium purification led to the perfection of both equipment and technique for high vacuum operations. These developments helped open the way for the entirely new field of vacuum metallurgy.

The reduction of metal oxides in vacuum has been studied by Dr. Kroll and Dr. Schlechten. They have been able to reduce many metals from their oxides under reduced pressures using carbon as a reducing …

A Study Of Radio Frequency Converters And Mixers, James J. Skiles

Masters Theses

"This thesis will present a detailed discussion of the principles of frequency conversion and the problems attendant to the design of converter stages. The topic of harmonic conversion has been singled out for a more extended treatment than is now available in the literature. This topic is the subject of the experimental investigation portion of this thesis. Harmonic conversion has applications in U-H-F receivers as well as in "Double Superheterodyne Receivers".

The discussion given to the frequency converter in the first section of this thesis will be without regard to any applications. General theory will be stressed, and most of …

The Specific Radioactivity And Ratio Of Hafnium To Zirconium In Ores From Different Continents And The Preliminary Design Of A Process For Producing Hafnium, Arliss V. Martin

Masters Theses

"An investigation of the weight ratio of hafnium to zirconium in ores from widely separated regions of the world was undertaken to extend knowledge on this ratio obtained by modern means and to compare with the results of previous investigators. This type of information is of interest in geochemical considerations and the value of some similar information in the literature has been vitiated by the relatively recent finding that past methods of analysis are not satisfactory. The specific radioactivity of the original ores was determined in an attempt to check the proposition originated by Hevesy and apparently generally held by …

Economic Analysis Of Secondary Distribution Networks, Charles F. Cromer

Masters Theses

"In the early history of commercial electricity in heavy load density areas, the d.c. Edison Network was developed extensively. As far as reliability is concerned it is exceeded by no system. At the present time it has been developed to the extent of automatic and non-automatic converters, motor-generator sets, booster sets and storage battery reserve capacity.

This type of network is fed from several substations in the area at utilization voltage.

As load densities have increased, the large amounts of copper required, the cost of substation sites and large rotating conversion equipment have made the expansion of the d.c. Network …

Design Of A Steam Power Plant To Be Erected In Mudanya, Turkey, Vahram Ogretmenoglu

Masters Theses

"The power plant, the design of which is submitted herewith, is to be erected in Turkey, at the center of the town of Kestik, in the district of Mudanya along the shores of the Marmora Sea. Mudanya is the harbor of the state of Brusa, and like most of the big cities, it is entirely electrified. However, electrification in Turkey has begun in the late twenty's; consequently, it has not yet been possible to bring electricity to the numerous small towns and villages. Several big projects have been undertaken for purposes of rural electrification, one of them being the erection …

The Effect Of A Uniform Layer Of Insulation On The Temperature Amplitude In Periodic Heat Flow, Ralph E. Schowalter

Masters Theses

"The object of this thesis is to determine by analytical methods the temperature at any time within a homogeneous semi-infinite solid protected by a uniform layer of insulation, while its one and only one plane face is subjected to a periodically fluctuating temperature. The temperature at an infinite distance within the solid is to remain constant, and the heat flow in the other two directions is to be considered negligible.

Periodically fluctuating temperatures are frequent in both nature and engineering. The surface of the earth is subjected to temperature changes which are very nearly periodic, and these changes are made …

Relationship Of The Overall Transfer Coefficient To The Factor In Ammonia Absorption, Ivan Lee Gray

Masters Theses

"Gas absorption has an important role in chemical and allied industries. It is used to separate one of a group of constituents from a gas stream. Poisonous or obnoxious gases may be removed from the gaseous waste products of chemical plants by absorbing them in suitable solvents.

Many investigations have been carried out and references too numerous to list have appeared in the literature on the general subject of absorption.

In all of this work one of the usual methods of reporting results has been to express the capacity of a piece of absorption equipment as an overall capacity coefficient …

The Effect Of Inlet Air Temperature On The Efficiency Of A Spark Ignition Engine, John B. Toomey Jr.

Masters Theses

"The object of this thesis is to determine the effect of inlet air temperature on the efficiency of an internal combustion engine. In most text books the subject is dismissed with mentioning the negative effect of warm air on the maximum output of the engine. This fact is recognized but since most engines are run at maximum output only a small percentage of the time, it would be possible to control the air temperature as the situation demanded. With the assumption that cold air could be used when full power is desired, it was decided to determine the effect of …

Investigation To Improve Recovery Of Copper And Gold From A Refractory Ore, Raymond Franklin Cathcart

Masters Theses

"Results of tests presented in this paper indicate that the Santa Maria del Oro ores might be processed by a method which should yield a gold recovery of 96 to 98 percent and a copper recovery of about 78 percent, both figures subject to an increase with further work and study of the problem.

In the method of processing outlined in Figure IX, the ores, mixed as under present operating procedure, would be crushed to minus 20-mesh and roasted with ten pounds of sodium chloride per ton of feed in a multiple-hearth, down-draft roaster at temperatures varying to a maximum …

Photoelastic Investigation Of Filleted Corners In Square Apertures In Flat Plates Subjected To Tension, Raymond Huston Bever

Masters Theses

"During recent years many advances have been made in solving engineering problems by mathematical means. While this method of solving problems is invaluable to the engineer, there are times when a rigorous mathematical solution cannot be readily obtained, and the engineer must resort to other methods, some of which are approximate.

This paper attempts to show the application of photoelastic investigation to such a problem. The results of this problem are quantitative, but they show without any doubt that this method of investigation has considerably influenced the modern design of machine parts and helped in many cases to improve construction …

Airflow Through Metallic Screening, Norman Bernard Wolk

Masters Theses

"The selection of the problem for which this paper offers a solution was made from a list of thesis subjects submitted to Dr. Aaron J. Miles by the United States Air Forces. This suggestion called for the development of a method whereby air flow through woven materials such as metallic screening and woven cloth could be predicted in terms of the pressure drop across the material. The range of the pressure differentials to be investigated was from zero to twenty inches of water.

After some preliminary work it became obvious that an investigation of the air flow through all types …

The Completion, Adjustment, And Operation Of A Grazing Incidence Vacuum Ultraviolet Spectrograph, William Clinton Johnson-Chamberlain

Masters Theses

"Most gases, and particularly oxygen and nitrogen, are nearly opaque to radiation in the region from about 1800 Å downward to about 2 Å and hence, for spectroscopic work in this region, the removal of these gases is mandatory. Popular usage generally refers to the range mentioned above as the vacuum ultraviolet. That there remains much experimental work to be done in the vacuum ultraviolet has been pointed out by Boyce in his exhaustive survey of vacuum ultraviolet spectroscopy. In order to fill in some of these gaps, Mr. L. H. Chapin, in the, spring of 1950, undertook the construction …

Torsional Modulus Of Rupture Of Thick-Walled Magnesium Alloy Fs-1 Tubing, Delbert R. Cox

Masters Theses

"Magnesium is taking a more prominent position in the structure of aircraft, and because of this, it is important that the mechanical properties of the material be understood more fully. In the high speeds of today, the tendency is toward the use of thick-walled tubing instead of the thin-walled tubing with stiffening structures. For this reason, it is of interest to note the characteristics of thick-walled tubing when subjected to torsion.

This thesis was first suggested by a circular letter on proposed thesis titles from the Commanding General, Air Materiel Command, Wright-Patterson Air Force Base, Dayton, Ohio. When interest was …

An Economy Study Of Vierendeel Trusses, Donald Lee Dean

Masters Theses

"Since the introduction of the pin connected steel truss in the United States in 1847 as a truss that could be actually designed, there has been very few basic changes in the truss as a structure. True, web members have been sloped or braced in many different ways to best adapt the truss for the structural materials being used, and over the protests of many , pin connections have almost wholly given way to riveted or arc welded connections, however, the basic idea of using all members as two force members has prevailed. Concern over the existence of bending stresses …

A Light Source To Be Used With A Vacuum Spectrograph, Roy George Woodle Jr.

Masters Theses

"A grazing incidence vacuum grating spectrograph for use in the vacuum ultraviolet was designed and partially constructed by Mr. L. H. Chapin, as a research project for a Master’s Degree. This instrument is designed to photograph the region of the spectrum from 100 Å to 1000 Å. As Boyce pointed out in his exhaustive review, there is much important observational work to be done in this region.

The author of this paper has undertaken to develop a satisfactory source for the region from 100 Å to 1000 Å. This is part of a project to photograph the emission and absorption …

A Lead Sulfide Near Infrared Detection System, William V. Cummings Jr.

Masters Theses

"The infrared region of the spectrum is conveniently divided into the near infrared, which extends from the red end of the visible to about 25 microns, and the far infrared, which continues to an ill-defined division point of approximately 1,000 microns. The near infrared region has been further subdivided on the basis of instrumental techniques so that the particular portion of the spectrum consisting of radiations of wave length up to 3 microns has become known as the photoelectric infrared.

Several types of detection instruments have been designed and perfected for work in the photoelectric region, but new methods and …

A Correlation Function For Liquid Argon, Walter Graham

Masters Theses

"X-ray scattering patterns have given considerable information concerning atomic distributions in matter, both crystalline and amorphous. Work on the diffraction of x-rays by crystals was begun in 1912 by Friedrich, Knipping, and Laue, and much valuable information concerning the arrangement of atoms in crystals has been supplied by this method. Diffraction of x-rays by gases was studied as early as 1911, and work in this field has given information concerning the arrangement of atoms in molecules and electron distribution in atoms. Work on the diffraction of x-rays by liquids was begun by Friedrich who obtained diffraction patterns of Canada Balsam, …

A Method Of Mining The Kumtepe Lignite Deposit Of Turkey, Hilmi Dokuzoglu

Masters Theses

"The Agacle lignite deposit, as a potential source of fuel, near Istanbul, Turkey has been used in this study to apply the principles of strip mining operations. The details of the deposit upon which this thesis is predicated will be presented later in this paper.

The fuel requirement of the city of Istanbul with a population of nearly a million is considerably greater then can easily be met. Some of the fuel needs are accommodated by electrical energy by producer gas, by bituminous coal brought from Zonguldak (about 200 miles from the city), by charcoal, and by fuel wood. During …

Geology And Mineralization Of The Jefferson Mine, Hardin County, Illinois, Robert Joe Cronk

Masters Theses

"Purpose of the Investigation: The geology of the Jefferson Mine was mapped to determine the relationship of the two fluorspar veins exposed on the 260-foot level to the single vein on the 200-foot level to study the mineralogy and paragenesis of the ore, and to gain any other information that would lead to a better understanding of the fluorspar deposits"--Introduction, page 1.

An Analysis And Evaluation Of Industrial Arts Projects Used In Midwestern Ohio, Henry W. Krause

Masters Theses

Chapter I

Introduction

Philosophy and Aims of Secondary Education

Recent social and economic conflicts have caused educators to examine their philosophies in the light of the needs of present-day society. The cultural view of education has given way to a growing emphasis upon the importance of functional education. Bode¹ tries to account for this when he says that the "rugged individualism" based upon a policy a "laissex faire" has changed to a conception that industry must contribute to the continuous development of functional education.

The classical curriculum of yesterday does not serve the youth of today with respect to …

Is Industrial Arts Benefitting A Representative Population Of Kalamazoo Central High School Boys?, D. John Lucas

Masters Theses

Chapter I

Introduction--Explanation of the Problem

Statement of the Problem.--It has long been the desire of the author to discover for himself and for others whether or not the beneficial experiences of industrial arts, as taught in the Kalamazoo Central High School, are being enjoyed by a typical cross section of the total number of boys enrolled in the school. Is industrial arts benefiting boys who are representative of the total population, or is it proving of benefit to a number who are characteristically different from those not electing it? This problem is one of concern not only to the …

A Follow-Up Study Of Kalamazoo Citizens Who Have Attended The Special Education Department For The Mentally Retarded Of The Kalamazoo Public Schools, Patricia H. Slesdet

Masters Theses

The philosophy of modern education emphasizes the necessity of meeting the individual needs of all boys and girls Education of all the children of all the people is a phrase with which all teachers of the modern school. are familiar as being the educational birthright of every child. Thus, it becomes the responsibility of the school to make pupil-activities an experience in living which is within the child's power or realization and appreciation and which will at the same time help to prepare him for a contributing adult citizenship.  As a result, we find a great deal of attention being …

Analytical Investigation Of Bending Effects On The Stability Of A Tube Subjected To External Pressure, Charles Young

Masters Theses

"The behavior of thin and moderately thick-walled tubes under various types of loadings has been a major problem of several leading industries for many years. Predominant among these, and the one for which this thesis was primarily undertaken, is the oil industry. The problem attacked in this thesis, however, is not limited to that industry alone, having ample application in industries that are sub-marine in nature, or any industry in which the application of external pressures on equipment is likely to be responsible for buckling failures...In this thesis, the problem of finding the effect of bending on the collapsing pressure …

A Study Of The Influence Of A Church School Upon Its Youth, Esther Jane Deweerd

Masters Theses

First Paragraph:

There is a growing need for more effective religious training for youth today. Educators recognize this and articles appearing in our magazine and papers sense it too. Studies and research into what the young people themselves feel also indicates that they recognize this lack in their training. The problem is receiving much thought and study by educators, church workers, and legislators alike, and valuable suggestions appear in these same periodicals, showing us ways of meeting this need. A few examples will show us what they are saying.

Effects Of A Reverse Order Of Firing Using Millisecond Delay Electric Blasting Caps In A Quarry Operation, Reginald John Jones

Masters Theses

"Evidence of the steady increase in the production of quarries is a reflection of the improved blasting practices that are being used. New explosives, the new millisecond electrical blasting caps and the endless experimentation carried on by both manufacturer and operator continue to aid or better the old methods of quarry blasting. In many instances the better results were obtained from practices hitherto unknown or at least unused. This report describes the results obtained from comparing quarry rounds shot in the accepted firing order and those shot in the reverse order of firing. The purpose of the report is to …

The Energy Levels Of Potassium Chloride, Clifford L. Adams

Masters Theses

"An understanding of the electronic energy states of solids has long been considered of importance. And the energy levels of the alkali halides have been the subject of much study in recent years. The present work is an attempt to set up an energy-level diagram for potassium chloride"--Introduction, page 1.

Principles And Practices Controlling The Use Of Earthmoving Equipment, Woodrow John Latvala

Masters Theses

"The purpose of this study is to show how the efficiency in earthmoving projects can be increased by the application of engineering principles. Efficiency can be increased by choosing equipment to fit the given set of conditions; and, having chosen the equipment, operate it at its maximum efficiency. In order to choose the right equipment it is necessary to study the conditions under which the equipment must operate. It is then necessary to study the machine in order to ascertain its adaptability to the existing conditions"--Introduction, page 1.

The Economic Spacing Of Contraction Joints In Reinforced Concrete Pavements, Wilbert Frederick Wegener

Masters Theses

"Structurally, there are two types of joints used in concrete pavements: (a) the tied, or permanently-closed joint; and (b) the open or free type of joint. The permanently closed joint utilized tie-steel of some form to keep the joint from opening. Usually, this steel is in the form of short individual bars extending across the joint and bonded to both slabs (designated as "tie-bars") or in the form of distributed reinforcement. The remaining method of classification, that of refering [sic] to the joint purpose, gives the expansion joint, contraction joint, and warping joint. An expansion joint is, as the name …