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Articles 17371 - 17400 of 18626
Full-Text Articles in Entire DC Network
A Study Of Rotational Critical Speeds For A Multi-Mass, Multi-Span System, Pravinchandra M. Upadhyay
A Study Of Rotational Critical Speeds For A Multi-Mass, Multi-Span System, Pravinchandra M. Upadhyay
Masters Theses
"It is well known that the unbalanced inertia forces present in rotating shafts set up violent vibrations in a transverse direction at certain speeds known as critical speeds, whirling speeds or whipping speeds. Therefore one who deals with the design of rotating machine parts, such as turbine rotors, multi-cylinder engine crankshafts etc., must consider transverse vibrations of rotating parts.
Practical solutions for finding the critical speeds of simple rotating systems, such as a single disk on a shaft with a single span, were derived by many authors. But as the number of loads and spans increases the problem becomes complex …
Investigation Of Ablation Materials, John Martyn Schattyn
Investigation Of Ablation Materials, John Martyn Schattyn
Masters Theses
"The desired result of this paper is to determine what effect the physical and thermal properties of a material have on the ability of that material to act as an ablation heat shield. On the basis of their physical properties, five materials, nickel, beryllium, fused quartz, teflon, and phenolic-nylon, were chosen as examples.
The tools used for this study are heat transfer equations involving a change in material phase. The resulting criteria may be assumed applicable to any material exhibiting one of the four types of ablation processes"--Abstract, page 2.
The Performance Of A Mechanically-Aided Countercurrent Extraction Column., Jerry James Carr
The Performance Of A Mechanically-Aided Countercurrent Extraction Column., Jerry James Carr
Masters Theses
"In recent years liquid extraction has become a major industrial method for the separation of liquid solutions. Liquid extraction has proven successful in some separations performed only with great difficulty by other, more common mass-transfer operations. Th e industrial utilization of liquid extraction has resulted in considerable interest in the design and performance correlations of high-capacity, high-efficiency extraction equipment.
Continuous countercurrent columns, filled with various packings, baffles, and plates, have been found to be relatively ineffective in liquid extract on service. The density difference of the contacted phases is generally insufficient to, by itself, cause the intimate contact necessary for …
Dissolution Rates Of Zone Refined Iron And Steel In Hydrochloric And Sulfuric Acids And In Sodium Chloride Solutions., Gary E. Welch
Dissolution Rates Of Zone Refined Iron And Steel In Hydrochloric And Sulfuric Acids And In Sodium Chloride Solutions., Gary E. Welch
Masters Theses
"Dissolution rates for two carbon steels were deter mined in four concentrations of sulfuric acid at five temperatures and in four concentrations of hydrochloric acid at four temperatures.
No general relationship was found for the variation in activation energies in sulfuric and hydrochloric acid. An explanation of the difference in the reaction rates and a possible explanation of the activation energy is presented on the basis of chunk formation.
The results of this investigation indicate an electrochemical control mechanism for the dissolution reaction of steel in acid solutions.
Results of dissolution rate studies in sulfuric and hydrochloric acid solutions and …
The Construction And Analysis Of An Amplifier For Ultrasonic Research, Jerry John Koelling
The Construction And Analysis Of An Amplifier For Ultrasonic Research, Jerry John Koelling
Masters Theses
“An amplifier to be used for ultrasonic pulse methods was constructed and tested. The frequency range lies between 100 cycles per second and 2 mega-cycles per second and, if tuned circuit plug-in units are used, may be increased to approximately 4 mega-cycles per second. Special demands upon the amplifier are discussed along with basic acoustic attenuation measurements in solid state physics”--Abstract, page ii.
A Study Of Methods For Determining Confidence Intervals For The Mean Of A Normal Distribution With Unknown Varience By Comparison Of Average Lengths, Karl Richard Kneile
A Study Of Methods For Determining Confidence Intervals For The Mean Of A Normal Distribution With Unknown Varience By Comparison Of Average Lengths, Karl Richard Kneile
Masters Theses
“The purpose of this thesis is to briefly review various properties which may be desirable for a system of confidence intervals; and to empirically determine whether the system of confidence intervals obtained from the Student’s t distribution will produce shorter average lengths than those obtained by other methods which may be used. It was concluded from the results of an empirical investigation that there was no significant difference between the average lengths of confidence intervals obtained from a family of distributions of which the Student’s t is a member"--Abstract, page ii.
The Effect Of Reradiation On Heat Transmission, Arvindkumar M. Shah
The Effect Of Reradiation On Heat Transmission, Arvindkumar M. Shah
Masters Theses
"In heat transmission by radiation, it is very easy to find the heat transmitted from one surface to another. Much work has been done in this area. The problem becomes complicated when the two surfaces are enclosed or joined by an enclosure. Such problems frequently arise in the design of furnaces. One problem is linked with the economy of fuel, by proper consideration of heat losses through the openings in furnace walls such as doors and burner openings. A second problem is associated with the heating capacity and useful heat transfer through the openings such as heat ports in walls …
Heat Transfer Through A Honeycomb Sandwich Panel, Jayantilal J. Darji
Heat Transfer Through A Honeycomb Sandwich Panel, Jayantilal J. Darji
Masters Theses
"Progress brought about by human ingenuity and technological developments has been always accompanied by fresh problems, the successful solution of which enables still further progress.
The recent developments in space exploration and exploitations are astounding. The coming years are likely to bring forth many remarkable achievements. Except for several engineering problems encountered with these developments the pace of progress is to study the heat transfer from honeycomb sandwich panels as an outer skin of high performance flight vehicles. The quantity of heat transferred through the panel is important in study of such vehicles, and methods or equations for determining this …
The Location Of Underground Points By Means Of A Magnetic Dipole, Anthony Del Prete Jr.
The Location Of Underground Points By Means Of A Magnetic Dipole, Anthony Del Prete Jr.
Masters Theses
"The object of this study was to design, construct, and test an electromagnet that could, from an underground location, generate a magnetic field which could be located at the surface, and that was portable enough to be carried through a cave. This could then be used to locate points in a cave relative to the surface.
A 20 foot solenoid composed of four five-foot sections was built and magnetized by a lightweight rechargeable four-cell eight volt battery. The total weight of the equipment was 30 pounds.
The magnet was calibrated by erecting it and measuring its vertical intensity with a …
Analysis Of A Char-Forming Ablator, William J. Reilly
Analysis Of A Char-Forming Ablator, William J. Reilly
Masters Theses
"The purpose of this thesis is to conduct an analytical analysis of a char-forming ablation material. This is one phase of ablation heat transfer.
Fourier's general equation for one dimensional heat conduction is transformed to moving coordinates and is then solved using the applicable boundary conditions. Solutions of this equation are valid for initial studies in ablation heat transfer"--Abstract, page ii.
Sedimentary Petrography And Environments Of Deposition Of The Plattin Group, Cliffdale Hollow, Jefferson County, Missouri., Narendra M. Naiknimbalkar
Sedimentary Petrography And Environments Of Deposition Of The Plattin Group, Cliffdale Hollow, Jefferson County, Missouri., Narendra M. Naiknimbalkar
Masters Theses
"Petrographic and depositional environments studies were completed on selected Plattin Limestone rock-samples from the Drill-cores of Cliffdale Hollow area, Jefferson County, Missouri.
Petrographic analysis of forty-four thin sections and the detailed megascopic study of the samples revealed the different types of limestone rocks which were classified on the basis of Folk's (1959) Carbonate Classification. As to the environments of deposition of the Plattin Limestone determined by petrographic study, it has been concluded that this environment was one of low to medium agitation and low to medium organic activity.
Chemical analysis of the Plattin Limestone samples revealed the presence of the …
Phase Extent Of Gaas, Gasb, And Insb, And Solid Solubility In The System Gaas-Gasb Determined By The Lattice Constant-Density Method., Chang Don Kim
Phase Extent Of Gaas, Gasb, And Insb, And Solid Solubility In The System Gaas-Gasb Determined By The Lattice Constant-Density Method., Chang Don Kim
Masters Theses
"The lattice constant of the homogeneous gallium arsenide varies from 5.65298A0 to 5.65J26A0 at 25° c with a change of composition in the range from 49-935 to 50.015 atomic percent gallium. The lattice constants of g allium and indium antimonide are 6.09592A0 and 6.47876A0 at 25 ° c, respectively and the extent of the phases of gallium and indium antimonide could not be found in this work.
The thermal expansion coefficient of gallium arsenide is 6.4 x 10-6/0 C in the range between 10 and 65° c regardless of composition, ar.d those of …
Removal Of Alkyl Benzene Sulfonate By Precipitation With Cationic Surfactants., Phillip E. Custer
Removal Of Alkyl Benzene Sulfonate By Precipitation With Cationic Surfactants., Phillip E. Custer
Masters Theses
"The extensive use of synthetic detergents, particularly the nonbiodegradable alkyl benzene sulfonate (ABS), has created many difficulties in water and wastewater. Although a number of processes have been proposed for the abatement of the synthetic detergent problem, a completely satisfactory solution has yet to be developed.
Following a preliminary investigation, three cationic agents, Bionol R0-50, G-263 and Primafloc C-5 were selected to be studied in detail in order to determine their ability to remove ABS by precipitation. Studies were conducted in deionized water, river water and domestic sewage systems using an initial ABS concentration of 10 mg/1 and cationic dosages …
Economical Span Length Ratios For Four Span Continuous Girder Bridges., C. C. Jogani
Economical Span Length Ratios For Four Span Continuous Girder Bridges., C. C. Jogani
Masters Theses
"This study presents the results of an analysis of maximum movement in a four span continuous bridge with total span length of 100¹, 200¹, 300¹, and comparison with maximum moment on three span continuous bridge with total span length of 200¹ and 300¹. The four span continuous bridge was found to have a maximum moment which was 46% that of the three span bridge at both 200¹ and 300¹ length"-Abstract p. ii
Hydraulic Transportation Of Coal In Open Flumes., Nallapu Narayan Reddy
Hydraulic Transportation Of Coal In Open Flumes., Nallapu Narayan Reddy
Masters Theses
"The objective of this study is to design a simplified form of hydraulic transportation system using open-flumes and operated by gravity in pitching coal seams. This type of system is to be used in conjunction with mining by hydraulic methods where the water used for the extraction of coal can also be used for the loading and transport functions"--Introduction p. 1
The Effect Of Haunched Members On Vierendeel Trusses, Rashmikant D. Parikh
The Effect Of Haunched Members On Vierendeel Trusses, Rashmikant D. Parikh
Masters Theses
"The purpose of this study was to analyze a Vierendeel Truss and determine the effect of haunches on moments. Loads were applied at the interior panel points in sequence. The classic slope-deflection method with coefficients taken from a table of frame constants (8) was used for the analysis.
In this investigation, one effect of haunches was determined to be the distribution of moments more evenly throughout the structure. Also, they insure rigidity of the joints and increase architectural flexibility"--Abstract, page ii.
Determining Stability Of Nonlinear Control Systems Via Lyapunov's Method., John Joseph Komo
Determining Stability Of Nonlinear Control Systems Via Lyapunov's Method., John Joseph Komo
Masters Theses
"The problem undertaken in this thesis is to present Lyapunov's method of stability as i t applies to control systems and to use it in the stability analysis of nonlinear control systems. The variable gradient method of generating Lyapunov functions is presented since this seems the best general procedure for obtaining Lyapunov functions. Also, the integration of matrices method is presented as a comparison. ii
Procedures for the use of the variable gradient method and the integration of matrices method are written and several examples are used to illustrate these procedures.
It is concluded that Lyapunov's method is very definitely …
The Reaction Of Sodium Iodide In Acetone With Halogenated Epoxides -- A Mechanism Study, Thomas E. Breuer
The Reaction Of Sodium Iodide In Acetone With Halogenated Epoxides -- A Mechanism Study, Thomas E. Breuer
Masters Theses
"l-bromo-2,3-epoxybutane reacted with sodium iodide in acetone to give 3-iodo-l,2-epoxybutane in 70.1 per cent yield. 3-bromo-l,2-epoxybutane produced l-iodo-2,3-epoxybutane in 69.9 per cent yield when it was allowed to react with a solution of sodium iodide in acetone. No other product could be isolated after either reaction, although it is possible that another compound may have been produced in very small amounts. The iodoepoxides were oxidized to the corresponding α-iodoacid in approximately ninety per cent yield by silver oxide"--Summary, page 40.
An Equilibrium Study Of The System Bi-S-H₂, Don Hie Lee
An Equilibrium Study Of The System Bi-S-H₂, Don Hie Lee
Masters Theses
"An experimental study has been conducted to determine the equilibrium behavior of the system Bi-S-H2. The system was studied by equilibrating H2-H2S gas mixtures with Bi(l)- Bi2S3(s) two-phase mixtures at temperatures of 500°, 600°, 700° and 750°C in a circulating type equilibrium apparatus. The equilibrium gas mixtures were analyzed by a Fisher Gas Partitioner with a reproducibility of approximately 0.06 %.
A linear free energy equation has been derived from the results with an average deviation of ± 1 Kcal. This deviation is well within the accepted experimental accuracy for …
The Anodic Dissolution Of Zinc In Aqueous Solutions, Glenn E. Stoner
The Anodic Dissolution Of Zinc In Aqueous Solutions, Glenn E. Stoner
Masters Theses
"The increasing demand for protective metals as coatings and non-corrosive alloys has stimulated extensive research on the fundamental behavior of metals in corrosive media.
One of the problems still unsolved is the nature of the mechanism of the anodic dissolution of metals like zinc, magnesium, beryllium, cadmium, and aluminum in aqueous salt solutions. Several schools of investigators have proposed different and opposing theories to explain the discrepancies which often arise between coulometric data and the weight loss of metal electrodes in certain salt solutions.
The purpose of this investigation was to obtain experimental data for the anodic dissolution of zinc …
Investigation Of Measures Of Ill-Conditioning, Thomas D. Calton
Investigation Of Measures Of Ill-Conditioning, Thomas D. Calton
Masters Theses
“The object of investigation in this study is that of ill-conditioning in the solution of a system of linear equations. Ill-conditioning arises when the solution is very sensitive to small changes in the coefficients of the unknowns.
A study is made in this paper of the various proposed measures of ill-conditioning for the purpose of finding the most practical method or measure for determining whether a system is ill-conditioned.
The problem of near-singular or ill-conditioned systems is of great importance in the solution of linear systems because of the extensive use made of them in practical situations. Solution of a …
A Simplified Method Of Estimating Drilling And Blasting Costs Of A Highway Through-Cut Excavation In Rock, Donald J. Roberts
A Simplified Method Of Estimating Drilling And Blasting Costs Of A Highway Through-Cut Excavation In Rock, Donald J. Roberts
Masters Theses
"The development of cost estimating methods has been the most neglected phase of highway engineering. Overlooked in particular has been the development of an easily understood and easily applied method of estimating the costs of the drilling and blasting operations involved in a highway through-cut excavation in rock.
This investigation developed such a method by adapting and applying recent developments in the blasting planning field. The study was limited to small diameter blastholes and excavations in lifts of less than thirty feet. Normal efficient construction practices were presumed.
It was found from the investigation that the blast geometry and, subsequently, …
Viscosities Of Various Binary Non-Polar Gaseous Mixtures., Gerald Lee Stevenson
Viscosities Of Various Binary Non-Polar Gaseous Mixtures., Gerald Lee Stevenson
Masters Theses
"Viscosity is an important physical property involving the transport of momentum in a fluid. Momentum is transferred within a fluid under an existing velocity gradient as the driving force. Since momentum transfer is actually attained by the dynamic interaction between particles of mass, a description of molecular interaction is essential in order to accurately predict the viscosity of a fluid. Temperature affects fluid viscosity by increasing the kinetic energy of the fluid system and thus the frequency by which molecules are involved in interaction. There have been many theoretical studies made concerning the intermolecular potential energy statements which serve as …
Behavior Of Clay Under Compaction By Vibratory Rollers., Glenn R. Taylor
Behavior Of Clay Under Compaction By Vibratory Rollers., Glenn R. Taylor
Masters Theses
"This thesis presents an analysis of the behavior of a lean clay when compacted by commercial vibratory rollers using the results of field investigations conducted by the U. S. Army Engineer Experiment Station, Vicksburg, Mississippi. Conclusions reached indicate that a lean clay soil will behave substantially the same under compaction by a vibratory roller as it does under other conventional methods of field compaction. The relationship of amplitude to the density and moisture content is also examined in this paper with the conclusion that the variations in amplitude of a vibratory roller is not significant as a measure of the …
Methods For The Determination Of The Thermal Conductivity Of Solids., A. M. Sivadasan
Methods For The Determination Of The Thermal Conductivity Of Solids., A. M. Sivadasan
Masters Theses
"The thermal conductivity of materials is of considerable practical and theoretical interest. Numerous publications on this subject have been presented with widely varying approaches and applications being made. Perhaps for no other thermal property are the published results so widely divergent and subject to such great uncertainty, particularly at high temperatures. This is partly due to unsolved difficulties in measurement, but perhaps to an even greater extent to the fact that the thermal conductivity of a material depends on its physical characteristics as well as some environmental factors such as humidity and temperature. In the case of metals or alloys, …
Spin Relaxation Of Optically Pumped Rubidium., Kenneth Brian Steinbruegge
Spin Relaxation Of Optically Pumped Rubidium., Kenneth Brian Steinbruegge
Masters Theses
"This Thesis is intended to be a self-contained guide to the theory and experimental procedures of optical pumping in one of its most usual applications. A particular study is made of optical pumping of rubidium vapor and results are given stating the most efficient temperature range in which to produce large populations of optically oriented rubidium atoms. The thermal relaxation time for optically orientated rubidium for a particular system is given and the effect of trapped resonance radiation is considered in the interpretation of the experimentally obtained curves"--Abstract, p. ii
Determination Of The Standard Free Energy Of Formation Of Zr₃S₂, Peter E. Otten
Determination Of The Standard Free Energy Of Formation Of Zr₃S₂, Peter E. Otten
Masters Theses
"The Knudsen effusion method was used to find the equilibrium magnesium pressure for the reaction
3 Zr (s) + 2 MgS (s) = 'Zr3S2' (s) + 2 Mg (v)
By using known standard free energy data for the formation of magnesium sulfide and by using the equilibrium magnesium pressure, the standard free energy of formation of Zr3S2 was calculated and could be expressed by the equation
Δ F° = -139,800 + 49.13 T cal/mole
in the temperature range 900 to 1100°C.
It was also found that Zr3S2 was the zirconium …
The Measurement Of The Life-Time Of The 62P3/2 State Of Thallium, Danny Hale Sokolowski
The Measurement Of The Life-Time Of The 62P3/2 State Of Thallium, Danny Hale Sokolowski
Masters Theses
The measurement of the lifetime of the metastable 62P3/2 state of thallium is discussed. Time-sampling equipment techniques and instantaneous methods of display on an oscilloscope for measuring the lifetime are explained. The lifetime is measured as a function of mercury vapor pressure. The decay of the 5350 A thallium line is also measured to give an indication of the effect of the imprisonment of the 3776 A resonance line. This decay of the 5350 A line is also in a mercury atmosphere"--Abstract, page ii.
Swelling Properties Of Putnam Soil, Oscar M. Palma
Swelling Properties Of Putnam Soil, Oscar M. Palma
Masters Theses
"Volume change of Putnam soil under different moisture contents and the swelling pressure developed by the soil at the same moisture contents were investigated using standard test procedures.
The theory of one dimensional consolidation of Terzaghi was reviewed as well as the literature on swelling and swell pressure.
It was found that swell depends mainly on the initial water content, while swelling pressure depends mainly on the dry density of the soil"--Abstract, page ii.
Stereoradiography As Applied To Problems Of Petrology., Martin Goldstone
Stereoradiography As Applied To Problems Of Petrology., Martin Goldstone
Masters Theses
"Stereoscopic examination of radiographs of rock and ore samples allows a rapid, cursory determination of texture and structure without time consuming preparation and use of thin sections. In addition, volumetric estimates of known mineral components can be made providing they possess significantly different x-ray absorption characteristics.
Stereoscopic effect was most pronounced for specimens having well defined components of structure such as bedding, banding, lineation, inclusions, textural variations and moderate to large x-ray absorption differences. In general, these conditions were best met by ores or ore minerals with their related gangue minerals.
Stereoscopic examination was not successful in revealing twinning or …