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Articles 7021 - 7050 of 7904
Full-Text Articles in Entire DC Network
A Study Of The Effectiveness Of Listening Instruction In Grades Five And Six, Terry R. Shepherd
A Study Of The Effectiveness Of Listening Instruction In Grades Five And Six, Terry R. Shepherd
Masters Theses
No abstract provided.
A Study Of The Subsequent Academic Achievement Of Students At Eastern Illinois University Who Were Readmitted To The University After Having Been Dropped For Low Scholarship, Jerry D. Zachary
Masters Theses
No abstract provided.
A Model Study Of The Application Of Roof Bolts Under Unsymmetrical Loading Conditions, Friedrich H. K. Esser
A Model Study Of The Application Of Roof Bolts Under Unsymmetrical Loading Conditions, Friedrich H. K. Esser
Masters Theses
"When coal is extracted by the long wall mining method, two gate-roads on either side of the working face are driven with the advancing operation. In the surroundings of these openings the state of stress which existed prior to mining is not only disturbed by the drifting process of the gate-roads but also by the coal extraction in the long wall, resulting in an "unsymmetrical" stress distribution. Varying incremental pressure components and the high complexity of strata movements make it extremely difficult to control the rock behavior under unsymmetrical conditions by conventional support. Application of roof bolts as an auxiliary …
Gathering Haunch Design Data By Photoelasticity, Richard B. Heagler
Gathering Haunch Design Data By Photoelasticity, Richard B. Heagler
Masters Theses
"The haunching of beams and columns and the haunching of rigid frames is performed by design engineers for the purpose of relieving stress concentrations that might occur at discontinuities in structures. The haunch performs this relieving of stress concentration by increasing the rigidity of the structure at regions of high stress. Usually this design step is one of trial and error; that is, the engineer will select a haunch or method of haunching and then check to see if the result is sufficient for his purpose. This can be a time consuming process and can lead to uneconomical design.
In …
A Study Of A Second-Order Predictive Control System, Tarkeshwar Singh
A Study Of A Second-Order Predictive Control System, Tarkeshwar Singh
Masters Theses
"The purpose of this thesis is the study of a predictive control system by simulating it on an analog computer. Logic criteria for step reference inputs are derived by the phase- plane technique, and tie corresponding logic network designed to bring the error and error rate of the controlled system toward zero in the least possible time.
The responses of the predictive control system for step, ramp, sinusoidal and exponential reference inputs are investigated with primary emphasis placed on the rise time and overshoot for several values of step inputs of the reference.
Finally, recommendations are made for further investigations …
The Separation Of Germanium From Lead, Cadmium, And Zinc By Ion Exchange, Myra Sue Anderson
The Separation Of Germanium From Lead, Cadmium, And Zinc By Ion Exchange, Myra Sue Anderson
Masters Theses
"The object of this study was to investigate the ion exchange behavior of germanium in order to find a quantitative separation method applicable to the analysis of germanium in zinc ores.
Germanium had been predicted and described as eka-silicon by Mendeleeff, and was discovered by Winkler in 1886. The importance of the metal has increased very much since World War II because of its use as a semiconductor in diodes and transistors.
All commercial scale germanium is now produced as a by-product of base metal processing. Although the United States Bureau of Mines is conducting a program for the recovery …
Experimental Evaluation Of Thermal Strains And Stresses, T. F. Lehnhoff
Experimental Evaluation Of Thermal Strains And Stresses, T. F. Lehnhoff
Masters Theses
"This investigation is the study of a method for the experimental measurement of thermal strains. Using four electric strain gages (two of one type and two of another) the method will yield the normal and shear strains as well as the temperature change in any biaxial stress field. The gage types must be chosen for the range of temperature in which it is desired to measure the thermal stresses. The method described eliminates the need for extra resistors, thermocouples, unrestrained dummy gages at the same temperature as the active gages, special alloy gages for each type of metal and special …
An Investigation Of Lehmer's Method For Finding The Roots Of Polynomial Equations Using The Royal-Mcbee Lgp-30, James W. Joiner
An Investigation Of Lehmer's Method For Finding The Roots Of Polynomial Equations Using The Royal-Mcbee Lgp-30, James W. Joiner
Masters Theses
“The solution of the general polynomial equation f (x) = O, where f(x) = anxn + an-1xn-1 + … + a1x = ao, has received the attention of many mathematicians for hundreds of years and is at present in a very highly developed state. Even a cursory examination of the literature will reveal many volumes on this subject. However, this study is concerned primarily with the numerical methods for solving polynomial equations, hence the classical methods will be treated here only as they contribute to this field.
Virtually all of …
A Survey Of The Influence Of Selected Sulfides On The Thermal Decomposition Rate Of Zinc Sulfate, L. G. Twidwell
A Survey Of The Influence Of Selected Sulfides On The Thermal Decomposition Rate Of Zinc Sulfate, L. G. Twidwell
Masters Theses
"The influence which ZnS, CdS, Cu2S, PbS, and FeS has on the thermal decomposition rate of ZnSO4 was studied by measuring the SO2 gas evolved per unit of time for various ZnSO4-MeS mixtures at 600°C, and analyzing the solid phases by means of X-ray diffraction patterns.
The SO2 gas evolved upon heating the pellets was analyzed as a function of time by absorbing the gas in a solution of distilled water, H2O2, and NaOH, and measuring the time required for the SO2 to neutralize the NaOH. The gas …
Effect Of The Mixed Liquor Suspended Solids Concentration On The Treatment Of Dairy Wastes By Activated Sludge Process, Meredith Hambleton Saxer
Effect Of The Mixed Liquor Suspended Solids Concentration On The Treatment Of Dairy Wastes By Activated Sludge Process, Meredith Hambleton Saxer
Masters Theses
"The effect of the mixed liquor suspended solids concentration on the treatment of dairy wastes by the activated sludge process was investigated to provide original and basic information of value to the waste water treatment field.
The studies were conducted using a continuous flow activated sludge laboratory unit. Two different synthetic dairy waste systems were used in this investigation, the 0.05 Percent Skim Milk Waste System and the 0.1 Percent Skim Milk Waste System. These wastes provided BOD loadings of 43.9 and 91.1 lb. BOD per day per 1000 cu. ft., respectively, at the 12 hour detention period employed. Mixed …
A Study Of The Electro-Chemical Injection Of Ca(Oh)₂ Into Pure Kaolin Clay, Sam Michael Savas Jr.
A Study Of The Electro-Chemical Injection Of Ca(Oh)₂ Into Pure Kaolin Clay, Sam Michael Savas Jr.
Masters Theses
"The work presented in this thesis is the investigation and study of a possible and successful means of injecting an electrolyte solution into a fine grain soil mass with the use of electric current and to measure some of the changes of its physical properties. A NoKarb Georgia Kaolin Clay was treated by passing a preferential electrolyte solution of Ca(OH)₂ using direct current for a period of one and six days. The tests performed during this investigation included the following: (a) tri-axial tests, (b) atterberg limits, (c) pH determination, (d) moisture content change (from treatment), (e) visual settling of treated …
Investigation Of Flow Rates Through A Rockfill Dam With An Internal Spillway, Jerry R. Bayless
Investigation Of Flow Rates Through A Rockfill Dam With An Internal Spillway, Jerry R. Bayless
Masters Theses
"Tests were performed on a model of a rockfill dam with an internal spillway for the purpose of developing a method of predicting the flow rate through the dam. The flow rate depends upon the head but is affected by the rock size and the height of the impervious core; there- fore, these factors were varied in the study. A relation for flow rate in terms of head was found for each combination of rock size and core height used and was compared to the general weir equation to find the coefficient of contraction; thus the effect of changing core …
An Evaluation Of State Mineral Taxation In Missouri, Jerry Wayne Huffman
An Evaluation Of State Mineral Taxation In Missouri, Jerry Wayne Huffman
Masters Theses
"A study was made to evaluate the present taxes levied on the mineral industry in the State of Missouri. The corporate income tax, corporate franchise tax, and general property taxes were examined, in addition to the mine inspection fees and methods of local assessment of mineral properties.
It is suggested that the State of Missouri revise the method of application of the general property tax to mineral properties. Utilization of the principle of taxation of future profits and employment of qualified appraisers would provide a more equitable application of the general property tax.
It is recommended that the present mine …
A Study Of The Problems Of Design Of Optimum Vibration Absorbers For Multi-Mass Systems, James C. Villegas
A Study Of The Problems Of Design Of Optimum Vibration Absorbers For Multi-Mass Systems, James C. Villegas
Masters Theses
"The purpose of this investigation was to continue the preliminary work of Burrows on the application of tuned and damped vibration absorbers to the reduction of vibratory stresses in a multi-mass torsional vibration system. A hypothetical engine system was chosen for both investigations because it had many complicating factors and gave an eminently practical subject for study.
Attention was centered on the reduction of stresses resulting at higher speeds of the machine system and on developing methods and criteria for the designing of effective absorbers where several modes of vibration exist in the operating speed range of the machine"--Abstract, page …
A Tunnel Diode Parametric Down Converter, Leland Lovell Long
A Tunnel Diode Parametric Down Converter, Leland Lovell Long
Masters Theses
"The problem, as presented, is to derive analytical expressions for the conversion gain, bandwidth, and noise figure of a self excited tunnel diode converter and to verify, if possible, the validity of these express- ions by building such a converter. These analytical results are presented and discussed. The converter circuit is shown along with the resulting intermediate frequency output. Gain and bandwidth measurements are also given. It is concluded that the self excited converter could very definitely be of value as a low noise pre-amplifying device in the ultra-high frequency and microwave frequency ranges"--Abstract, page ii.
Seismic Investigation Of Flint Clay Deposits In East Central Missouri, Roland D. Dayley
Seismic Investigation Of Flint Clay Deposits In East Central Missouri, Roland D. Dayley
Masters Theses
"Seismic refraction surveys were conducted in several localities within the east central Missouri clay districts in order to determine the applicability and economy of this method as a clay exploration tool. Results of these surveys revealed that the sink-type clay deposits possess lithologic and structural characteristics that lend themselves favorably to this method of exploration.
Seismic records obtained from profiles shot across known deposits indicate that several factors other than velocity contrast serve to produce apparent seismic anomalies.
Some unforeseen time loss and expense was encountered because of malfunctions of the seismic equipment employed, which necessitated the purchase and installation …
The Experimental Determination And Prediction Of Ternary-Liquid Equilibria Data, Risdon William Hankinson
The Experimental Determination And Prediction Of Ternary-Liquid Equilibria Data, Risdon William Hankinson
Masters Theses
"Although the field of liquid extraction is of increasing importance in today's chemical industry, the ternary-liquid data so necessary to the design and study of extraction operations are available in the literature only to a limited extent. During the twentieth century, approximately 120 ternary-liquid systems have been studied. However, limiting solubility data have been reported for approximately one-third of these systems, and about 30 per cent of the equilibria data reported for the remainder of these systems are incomplete or inaccurate.
Within limits, liquid equilibria data may be calculated for a ternary system from the properties of its constituents which …
Study Of The Design Of Reinforcement For Prestressed Concrete And Blocks, Charles Robert Hoffman
Study Of The Design Of Reinforcement For Prestressed Concrete And Blocks, Charles Robert Hoffman
Masters Theses
"This thesis is an analysis of the transverse tensile stress condition in an end block of a prestressed concrete beam. A stress analysis was made by photoelasticity and compared to the mathematical solutions and experimental solutions performed by others on concrete models. The photoelastic model was made from a piece of Columbia Resin, 39.
Whatever method is chosen to determine the stress condition, there is no exact code that can be established to fit the various type problems which arise"--Abstract, page 1.
Fractionation Of Fission Elements By Electrodialysis, George Joseph Bub
Fractionation Of Fission Elements By Electrodialysis, George Joseph Bub
Masters Theses
"The development of nuclear power has presented countless problems to the scientists and engineers of today. A problem of extreme importance is the disposal of radioactive wastes. Another is the recovery of some of the useful radioisotopes from fission product waste solutions. This investigation is concerned with the recovery of some of the fission elements for use in radiochemical and medical research and in industry.
At present little effort is made to recover useful fission elements. The fission product waste solutions are treated to reduce the volume and are stored until the radiological hazard is reduced and are then disposed …
Porous Cooling Of A Pile, Tarsem Singh Purewal
Porous Cooling Of A Pile, Tarsem Singh Purewal
Masters Theses
"In this investigation the problem of a limiting case of steady state one dimensional solid-fluid Newtonian heat transfer is examined in which an incompressible non-heat generating coolant fluid is flowing through a heat generating porous plate.
The effect of grain size on the Newtonian heat transfer in the porous plate with various kinds of internal heat generations is determined analytically. The temperature difference between the solid and the coolant fluid through the porous plate is determined. All the previous studies assume that in the porous plate, coolant fluid temperature and solid temperatures are approximately equal. This analysis eliminates this simplifying …
The Dissolution Of Magnesium In Strong Acids, Baldev K. Bhatia
The Dissolution Of Magnesium In Strong Acids, Baldev K. Bhatia
Masters Theses
"The rapidly growing demand for magnesium and magnesium-base alloys in the manufacture of aircraft has led to a great amount of research into the corrosion characteristics of these materials. The result of such research has been the development of suitable magnesium alloys and protective coatings to retard corrosion.
The standard electrode potential of magnesium lies between -2.35 volts and -2.54 volts at 25⁰C (hydrogen scale). Thus, magnesium lies next to aluminium in the electrochemical series of elements. The atmospheric corrosion of magnesium has been studied under conditions of indoor and outdoor exposure. Under these conditions the initial attack is formation …
A Study Of Small Watersheds Within The State Of Missouri, Terence E. Harbaugh
A Study Of Small Watersheds Within The State Of Missouri, Terence E. Harbaugh
Masters Theses
"The present status of data from watersheds in the under 10 square mile drainage area classification, pages much to be desired. However, this study of 45 small watersheds within the State of Missouri gives an indication that surface runoff from these basins may be predicted with a fair degree of accuracy. The inclusion of a shape factor AL2 and its use as a portion of the "basin index" (AL2S1/2) gives accurate results as a predictor of the "mean annual flood". The mean annual flood may be adequately computed by the formula, MAF = 113(AL2 …
A Theoretical Study Of The Mechanism For The Haeffner Effect, David Charles Jacobs
A Theoretical Study Of The Mechanism For The Haeffner Effect, David Charles Jacobs
Masters Theses
"In 1953, E. Haeffner reported that when he had passed a direct electric current through a length of capillary filled with liquid mercury, the lighter mercury isotopes were enriched at the positive terminal and the heavier mercury isotopes were enriched at the negative terminal. This phenomenon is referred to as the Haeffner Effect. Since Haeffner’s original experiment, other investigators have obtained similar results in other liquid metal systems.
When a direct electric current passes through a metallic conductor a free energy gradient is established. The direction of the negative free energy gradient is in the direction of the positive terminal. …
Linear Feedback Control System Compensator Design Under Specified Constraints, Keikhosrow Irani
Linear Feedback Control System Compensator Design Under Specified Constraints, Keikhosrow Irani
Masters Theses
"The purpose of this thesis is to find the necessary and sufficient conditions for the design of compensators, following the concepts developed by Ross, Warren, Hsu and Sanden.
The main object that motivates this investigation is to design the lead or lag compensator networks for a given linear feedback system when there are these constraints.
- Gain of the system is constant.
- The steady-state error is invariant.
- The dominant poles of the closed-loop transfer function are specified.
Consideration of the problem is in two parts:
- a. Derivation of necessary and sufficient conditions of compensator design that fulfill the three constraints.
- b. …
Mechanics Of The Voussoir Arch As Applied To Block Caving, Christopher Haycocks
Mechanics Of The Voussoir Arch As Applied To Block Caving, Christopher Haycocks
Masters Theses
"The theories of ground failure in massive rock with special reference to the problem of the mechanics of block caving were studied and evaluated.
The mechanics of arch or dome formation underground were studied quantitatively using the Voussoir arch theory. The effect of shear stress on the arch stability was considered and found to affect the system only when the arch height increased beyond certain limits.
A theory of the mechanism of ground failure in an undercut block using the dome theory was advanced. Photo- elastic model studies were used to support the conclusions reached"--Abstract, page i.
The Dielectric Strength Of Some Anti-Corrosive Paints, George Albert Chappell Iii
The Dielectric Strength Of Some Anti-Corrosive Paints, George Albert Chappell Iii
Masters Theses
"Corrosion has been one of the costly problems to industry because each year losses due to corrosion are in excess of six billion dollars. Corrosion is caused by the tendency of all metals to become oxidized and return to their natural state. Oxidation may be suppressed by restraining the flow of electrons from the system, thereby inhibiting corrosion.
One effective means to prevent rusting is by applying a barrier of paint between the system and the corrosive atmosphere. Not all paints, however, are equally effective as corrosion inhibitors. At present, the only effective means of determining the corrosion resistant ability …
A Model Study Of The Behavior Of Elastic Liners In Shallow Underground Openings, Martin Samuel Oudenhoven
A Model Study Of The Behavior Of Elastic Liners In Shallow Underground Openings, Martin Samuel Oudenhoven
Masters Theses
"Models of epoxy resin were used in a stress freezing technique to determine areas of possible failure in lined circular openings. These models were loaded in a centrifuge for a fixed period of time, after which they were analyzed photoelastically. The material characteristic changes, with time, were recorded on graphs and used in the analysis.
Two types of tests were conducted; one, where the lining thickness was changed and, the other, where materials of the liner and plate material were changed.
The resulting analyses furnished proof that the greater the rigidity of the lining, the higher the stress developed in …
A Comparison Of A-C And D-C Lead Compensation From D-C Prototype Networks, Piyush Parikh
A Comparison Of A-C And D-C Lead Compensation From D-C Prototype Networks, Piyush Parikh
Masters Theses
"The object of this thesis is to study the difference in transient and frequency response characteristics between a prototype d-c phase lead compensating network and an equivalent a-c phase lead compensating network.
A second order servo is selected to be compensated and five d-c prototype and equivalent a-c phase lead compensating networks are designed. The frequency characteristics of the a-c networks are obtained experimentally and these of the d-c networks are obtained analytically. The characteristics of both networks are compared and their differences are studied. The transient characteristics of the d-c and a-c compensated closed-loop systems to a step input …
A Comparison Of The Load Carrying Characteristics Of Hydrostatic Thrust Bearing Using Monatomic, Diatomic, And Triatomic Gases, Joseph C. Pigott
A Comparison Of The Load Carrying Characteristics Of Hydrostatic Thrust Bearing Using Monatomic, Diatomic, And Triatomic Gases, Joseph C. Pigott
Masters Theses
"The purpose of this investigation is to compare the load carrying characteristics of gases with different ratios of specific heat. The design, construction, and operation of an apparatus for testing and comparing the load carrying characteristics of gases are described. Several monatomic, diatomic, and triatomic gases were tested and the results evaluated and compared. The data are tabulated and displayed in a series of curves.
It was found that the monatomic gases exhibit a greater clearance for a given load and a greater total load carrying capacity than the diatomic gases which in turn have a greater clearance and total …
A Comparison Of Backwater Profile Computation, Alwin Chang Hsin Young
A Comparison Of Backwater Profile Computation, Alwin Chang Hsin Young
Masters Theses
"Bakhmeteff's, Von Seggern's, and the Standard Step methods were chosen for a comparative study of backwater profile determinations made with the assistance of a digital computer. This study concentrated on the M-l type of curves for different kind of prismatic channels; i.e. rectangular, trapezoidal, and parabolic channels. From the results obtained by each method for different channels, the consistency between the several methods and their applicability to all shapes of channel had been studied. Also the effect of the number of reaches used in flow profile determinations, the effect of the use of an average value of (1-ß), hydraulic exponents …