Engineering Commons^™

Study Of Relay Behaviour Under System Oscillations And Out Of Step Conditions, Emil D. Grigoriadis

Masters Theses

"The recent developments in harnessing electrical power have opened a new field in the improvement and betterment of the existing types of relays and the development of new types. Thus about 1930 the manufacturers introduced the high speed circuit breaker with operating times of the order of 8 cycles and the engineers awoke to the possibilities of high speed or one-cycle relays.

Many developments took place since that time which gave us the improved forms of Instantaneous Overcurrent Protective schemes, the Distance Relay Protection, the Carrier Current Protection and many others. Later, because of the war time problems of increased …

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 …

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 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 …

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 …

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 …

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 …

Efficiency Studies Of The Effect Of Moisture On The Power Consumption Of Mine Scrapers, Georges J. Vigier

Masters Theses

"Many years of practice have resulted in the standardization of several types of scrapers which are now commonly manufactured for use in mining. Although experience has brought out much information on scraping operations, no systematic studies of the efficiency of mine scrapers have been carried out before the experimental works done in the last few years at Missouri School of Mines and Metallurgy. "Purpose of Problem": The purpose of this present study is to consider the effect which moisture in the muck has on the efficiency as regards power consumption and amount of material scraped, of different types of mine …

Calculations Of Maximum Sag Of A Transmission Line With An Ice Load On One Span, Rodney A. Schaefer

Masters Theses

"An important problem concerning electric power lines is the calculation of the maximum sag occurring when there is an ice load on only one span. The object of this thesis is to determine a practical method for calculating the maximum sag of a transmission line, suspended on suspension insulators, with the aforementioned loading conditions. This paper is limited to the case where the supports of the transmission line are at equal elevations and all span lengths are equal"--Introduction, page 1.

Economical Span Length Ratios For Three-Span Continuous Girder Bridges, Donald Hindrik Timmer

Masters Theses

"The three-span continuous bridge is one of the most popular bridges used by highway departments at the present time. The low first cost and overall economy combined with the pleasing appearance of this type of bridge as compared to simple span structures has led most highway departments to use continuous spans whenever conditions permit. The design of three-span continuous bridges, as well as the design of any of the other bridge types, is usually carried out as an analysis rather than a design. In the case of the three-span continuous girder, with rolled steel beams, an initial assumption as to …

A Study Of Mine Scraper Efficiency On Materials Of Different Specific Gravities, Kermit Guy Rowley

Masters Theses

"The purpose of this study is to determine the effect that the specific gravity of the material scraped has on the power consumption and the efficiency of the common types of mine scrapers. As scraper weight, rope speed, and moisture content of the muck are important factors affecting the power consumption and efficiency, these variables are the ones considered for each type scraper. Two materials of different specific gravities are used in the study with an equal number of tests run on each material"--Introduction, Purpose of Problem, page 2.

A Study Of The Efficiency Of Split-Second Delay Electric Blasting Caps In Underground Limestone Mining, John B. H. Fitzwilliam

Masters Theses

"The introduction of electric blasting caps have delay intervals of the order of one-half to one second proved of advantage in many aspects of underground mining, particularly development work. Their use spread, until they now supersede fuse-and-cap firing wherever possible. Split-second delay electric blasting caps are a comparatively recent development from conventional delay caps. They have been found of practicable use in quarrying operations, and have been applied in many phases of underground mining. While evidence, to show that short-delay firing in quarrying is more efficient than instantaneous firing, is becoming increasingly conclusive, it remains to be proved that split-second …

The Study Of Effect Of Definite Grain Sized Sand On The Shearing Strength Of Clays, Faruk Omer Akkoseoglu

Masters Theses

"Slopes of all kinds, including mountains, hills, sea coast bluffs, river banks, and man made cuts and fills, stay in place only because of the shearing strength possessed by the soil or rock of which they are composed. The resistance of soils to shearing strength is probably the most important of all the soil properties to foundation engineers. Most of the serious structural failures which are due to unexpected soil behaviour are caused by deficiency in the shearing strength of the soil. Water, on the other hand, possesses no static strength in shear, therefore bodies of water have no surface …

Hydraulic Scale For Measurement Of Dynamometer And Other Forces, John Richard Barton

Masters Theses

"The object of this investigation is to design, build, test, and develop, a hydraulic type scale primarily to be used for measuring dynamometer forces. The scale however is not limited to use on dynamometers, but may be used for other types of force measurements such as the continuous weighing of material on a conveyor belt in conjunction with a recording pressure gage. The scale has numerous applications in determining forces where conventional scales are now used. This particular subject was chosen because of the need for a convenient, inexpensive, and accurate scale for use in measuring the force exerted by …

The Nature Of Molecular Films Of Oleic Acid On Quartz, Kenneth Lee Keating

Masters Theses

"The purpose of this research was to show the nature of oleic acid on quartz mineral by transferring calcium oleate films, known to be monomolecular and of a definite orientation, to the surface of a piece of quartz, and measuring the resulting coated mineral by contact angle technique"--Introduction, page 1.

A Comparative Study Of Some Rock Drill Bits, Charles Roger Knopp

Masters Theses

"The detachable single-use rick-drill bit has attracted considerable attention in the mining industry of the United States during the past few years. While this type of bit has been used for some time in other countries, it has been only recently that these bits have been manufactured in the United States. It was decided to test this type of bit and make a comparative study of a single-use bit and a widely used detachable rock-drill bit"--Introduction, page 1.

Effects Of Sand Admixtures On The Physical Properties Of Soils, Necati Kanatsiz

Masters Theses

"The purpose of this study is to determine the effects of sand admixtures on the physical properties of soils. Soil may be defined as a heterogenous [sic] collection of rock and mineral fragments whose decomposition and disintegration have been brought about by the action of physical, chemical, and biological forces, working singly or in combination...In the conviction that the study of soils, with respect to highway engineering, is becoming more and more important this study was undertaken in order to learn whether the addition of sand would lead to desirable results, and if not, at least secure some further addition …

The Theory Of Limit Design As Applied To Column Analysis, John Francis Mccarthy

Masters Theses

"In any discussion of compression members of a structure, account has to be taken primarily of the relative "slenderness" or bending weakness of the member. If the member be so short that axial loading causes very slight deflection at any point throughout the member, it is usually designated a simple compression member and no account is taken of the additional stresses due to the deflection. When, however, the ratio of the length to the least radius of gyration of the member becomes so large that bending stresses cannot be ignored, the member is usually called a column and its consequent …

Periodic Heat Flow In A Semi-Infinite Solid, Warren George Heidbrier

Masters Theses

"The object of this investigation is to determine by analytical means the temperature within a homogeneous semi-infinite solid, as a function of time, while the solid is receiving heat periodically by radiation on its one flat surface. Periodic heat flow means that heat flow is a continuous function of time and repeats itself at regular intervals. A semi-infinite solid has only one bounding plane and extends to infinity in all other directions...Much of this work deals with the soil temperatures of the earth both at the surface and at various depths. The surface of the earth is subjected to daily …