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Articles 2401 - 2430 of 3914
Full-Text Articles in Engineering
Power, Divergence, And Stability Factors Affecting The Use Of A Krypton Laser As A Multispectral Illumination Source, David Perry Owsley
Power, Divergence, And Stability Factors Affecting The Use Of A Krypton Laser As A Multispectral Illumination Source, David Perry Owsley
Masters Theses
"Specific performance characteristics of a krypton laser were measured. Evaluation criteria were dictated by the proposed use of the laser as a multi-wavelength illumination source. The laser output power, spectral power distribution, and output stability were measured as a function of wavelength and transverse mode order, to determine optimal operation characteristics. Data are presented defining the compromise between laser output power and beam divergence when the laser is operated multi-wavelength, and in several low-order transverse modes. There is an advantage of increased output power when the laser is operated in transverse modes higher in order than TEM00, but …
Relative Volatility In The System 1-Butene - N-Butane, Steven Lewis Walker
Relative Volatility In The System 1-Butene - N-Butane, Steven Lewis Walker
Masters Theses
"An apparatus suitable for the rapid collection of P-x data at constant T is described. Isothermal P-x data at 40, 70, 100, 130, and 160 degrees Fahrenheit at the extremes of the composition range for the 1-butene - n-butane system are presented as a demonstration of the suitability of the device for its intended purpose. Limiting values of the relative volatility for the binary are presented. The relative volatilities were calculated using limiting forms of the general coexistence equation which are given in the literature. Several recommendations are given for improvements of the equipment and experimental technique"--Abstract, page ii.
The Effect Of Porosity On Strength Degradation In Thermally Shocked Alumina, Russell David Smith
The Effect Of Porosity On Strength Degradation In Thermally Shocked Alumina, Russell David Smith
Masters Theses
"Strength degradation and crack propagation in Al2O3 are shown to depend on the initial strength and porosity of the material. Specimens were fabricated containing between 0 and 5% induced cylindrical, two dimensional, and spherical porosity. The strengths of the various porosity samples decreased discontinuously at a critical quenching temperature. No difference was observed in the critical temperature for the various aluminas; initial strength decrease occurred between 165°C and 175°C temperature differential. The strength retained after thermal shock decreased with increasing initial strength. The degree of damage sustained upon shocking was also characterized by crack density and crack …
The Linear New City -- A Pattern For New Cities Based On Efficiency Of Transportation, Public Services, And Land Use, Elbridge Wesley Bartley Iii
The Linear New City -- A Pattern For New Cities Based On Efficiency Of Transportation, Public Services, And Land Use, Elbridge Wesley Bartley Iii
Masters Theses
"The linear new city is defined as a city consisting of some arrangement of relatively narrow, high-density strips, served by various mass transportation systems. Such a new city would be ideally suited to the implementation of the latest technology. The concentration of development along the transportation route would allow certain economies in the supply of utilities and services, as well as insuring that open space would be readily available around and throughout the city. The provisions for transportation, housing, and governmental control should combine to produce a better quality of life for the inhabitants of the linear new city"--Abstract, page …
Nucleate Pool Boiling Of Refrigerant-Oil Mixtures From Tubes, R. L. Dougherty
Nucleate Pool Boiling Of Refrigerant-Oil Mixtures From Tubes, R. L. Dougherty
Masters Theses
"This experimental investigation was conducted to provide design heat transfer data for applications involving the nucleate pool boiling of Refrigerants 11 and 113 from the external surfaces of tubes. Tests were conducted with 0.625-in. o.d. and 1.125-in. o.d. commercial copper tubing; at 1 and 2 atmospheres pressure; and with refrigerant-oil compositions from 0 to 10 percent oil by weight. Results show that each of these parameters can affect the heat transfer coefficient"--Abstract, page ii.
Managerial Performance Appraisal, Benildus Wai-Young Lau
Managerial Performance Appraisal, Benildus Wai-Young Lau
Masters Theses
"Questionnaire surveys were sent out to two hundred medium-sized companies in industry. The study is an attempt to find the main cause for the unsatisfactory results in most appraisal programs and to make recommendations concerning the implementation of an effective performance appraisal program. Human factors play an utmost important role in the success of the entire appraisal program. An atmosphere of mutual understanding and trust should be established between the well trained supervisor and his subordinate so that the rapport between them can be brought to the highest possible level. Performance appraisal should be considered as an integral part of …
A Quantitative Analysis By Emission Spectroscopy Of The Metallic Constituents Of Biological Samples After Treatment By A Carcinogenic Agent, Charles R. Frydrych
A Quantitative Analysis By Emission Spectroscopy Of The Metallic Constituents Of Biological Samples After Treatment By A Carcinogenic Agent, Charles R. Frydrych
Masters Theses
No abstract provided.
Parametric Analyses Of Regenerative Steam Power Cycles, Vallabh Vithalbhai Vaghani
Parametric Analyses Of Regenerative Steam Power Cycles, Vallabh Vithalbhai Vaghani
Masters Theses
"This study analyzes the effect of inlet pressures, internal turbine efficiencies, pump efficiencies, extraction pressures and number of open feedwater heaters on the thermal efficiency of regenerative steam power cycles. Combinations of inlet and extraction pressures were introduced into digital computer programs in order to find the optimum extraction pressures for maximum thermal efficiency. The scope of study covered regenerative steam cycles with one, two, three, four, and five open feedwater heaters. One of the principle objectives of the study was to determine if there is some turbine extraction pressure or set of pressures which give maximum thermal efficiency for …
Measurement Of Turbulence In An Annular Jet, George Philip
Measurement Of Turbulence In An Annular Jet, George Philip
Masters Theses
"An experimental investigation was conducted for an annular jet which consisted of a circular jet and a concentric wake. The annular air jet mixed with quiescent atmospheric air. The jet velocity was kept constant at 137.0 feet per second which corresponds to a Reynolds Number of 73,200. Using the technique of hot-wire anemometry, mean velocities, turbulence intensities and Reynolds stresses were measured in the longitudinal and lateral directions. Two distinct flow regimes, the free stream jet regime and the diffusing jet regime, are observed. In the free stream jet regime, higher turbulence intensity and shear stress occur in the inner …
Design And Preliminary Testing Of A Rotary Internal Combustion Engine, Frank Darrell Statkus
Design And Preliminary Testing Of A Rotary Internal Combustion Engine, Frank Darrell Statkus
Masters Theses
"With the advent of legislation against pollution, and rising wage, manufacturing, and materials costs, the prime mover industry is presently intent on developing new economical, non-polluting methods of power. It was the hope of the author that the engine described herein would provide an advancement towards meeting the new requirements. The design and resulting prototype is an eight cylinder rotary internal combustion engine, weighing approximately sixty pounds, and operating on the tour stroke principle. Theoretical calculations were made to determine ideal horsepower, mean effective pressure, and efficiency. Ideal horsepower ranged from 38.7 to 62.8. A dynamic analysis of the pistons …
The Analog Simulation Of Heat Transfer Devices For The Smoothing Of A Fluctuating Fluid Temperature, Le Thai Son
The Analog Simulation Of Heat Transfer Devices For The Smoothing Of A Fluctuating Fluid Temperature, Le Thai Son
Masters Theses
"Equations are written to describe a heat exchanger with electrical energy input and also a large tank system which can have electrical energy input. The output temperatures were sampled and fedback to define the energy input to the two systems. These systems were simulated on an analog computer and the ability of the two systems to smooth a fluctuating temperature input was tested. The testing of the systems included trying different types of controllers in the control system as well as different size tanks for the tank system. A satisfactory smoothing of the output temperature was demonstrated after some modifications"--Abstract, …
Decimal-Base Binary Logic (Dbbl) Adders And Registers, James Oliver Bondi
Decimal-Base Binary Logic (Dbbl) Adders And Registers, James Oliver Bondi
Masters Theses
"This paper discusses a new type of base n adder and storage register. This new type of logic is called "n-base binary logic", or NBBL. The NBBL system is compared and contrasted with the Post base n system (a type of n-valued logic), the binary-coded base n system, and the straight binary system. The main purpose of this paper is to show that a decimal, or base 10, system can have some important inherent advantages over a binary system, such as greater daily operational efficiency. Furthermore, it is shown that a "decimal-base binary logic" system, or DBBL system, has inherent …
Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds
Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds
Masters Theses
"A state of the art regarding the thermal behavior of bridges and considerations to be given to the resultant thermal effects is presented. The results of studies related to the thermal effects on bridges are reviewed. Studies attempting to relate environmental factors to bridge temperatures, and subsequently to bridge movements and stresses, indicate that the task is extremely complex. Some correlation has been made between equations predicting bridge temperatures and movements based on weather bureau records. However, further research is needed to evaluate the effects of factors other than temperature, such as creep, shrinkage, and humidity on bridge movements and …
An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja
An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja
Masters Theses
"Fluidics, the new control technique finds its use amongst the conventional electronics and pneumatics due to some of its impressive features. Selected literature about bistable and proportional amplifiers has been presented for better understanding of the element behavior. Sensors; typical applications of fluidics have been described separately. An air flow velocity sensor has been set-up. Basically it consists of a cylinder placed across the air flow that sheds vortices in the wake due to 'Von Karman Vortex Street' phenomenon. The frequency of vortices gives a measure of velocity. The velocities obtained from the sensor have been compared to the ones …
Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang
Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang
Masters Theses
"Thermal expansion, thermal hysteresis, and the monoclinic tetragonal phase transformation of ZrO₂ have been studied with high temperature x-ray diffractometry. The initial transformation temperature in pure ZrO₂, on heating, is about 1150ºC. The transformation occurs over a 100ºC temperature range and thermal hysteresis occurs on heating and cooling. The mechanism of the transformation is related to preferred vibrational modes of atoms on the AO -CO plane of the monoclinic structure. Because the monoclinic BO axis is parallel with the tetragonal [110] axis, structural relationships can be seen to be a controlling factor in the transformation. Initiation of …
A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah
A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah
Masters Theses
"Four Liapunov functions used in stability studies are compared for accuracy on an eight machine power system. This comparison is made to determine which function is best in multimachine stability applications. Morgan's Estimating Technique is used to estimate when the Liapunov function would exceed its maximum value and thus to predict the critical switching time for the system"--Abstract, page ii.
The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel
The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel
Masters Theses
"In this report the steady-state near-resonant vibration of a hollow fluid-filled beam is considered. The energy dissipation caused by the beam-fluid interaction is approximated by introducing a viscous damping force into the Bernoulli-Euler beam equation. A theoretical expression is developed for the displacement of the hollow beam by solving this modified Bernoulli-Euler beam equation. Tests are made using a cantilevered fluid-filled box to simulate a unit of beam-fluid length. The band-width technique is used to determine the incremental viscous damping coefficient from test data. A variety of fluids are used in the box to determine the effect of the fluid …
A Mass Spectrometric Characterization Of Positive Ions Created In Simple Vacuum Diodes Incorporating Oxide Cathodes With Supplementary Analysis Of Background Gases, Larry A. Addington
A Mass Spectrometric Characterization Of Positive Ions Created In Simple Vacuum Diodes Incorporating Oxide Cathodes With Supplementary Analysis Of Background Gases, Larry A. Addington
Masters Theses
"Simple diodes were constructed utilizing oxide cathodes and nickel anodes. The cathodes were obtained by applying a mixture of barium, strontium, and calcium carbonates to a nickel filament and decomposing them to yield the oxides. The products of decomposition were analyzed by monitoring the composition of the background gases in the vacuum chamber. A portion of the flux of positive ions bombarding the cathode during diode operation was analyzed. It was possible to determine the region of origin of the ions and their potential energy at the time of formation. Positive ions of chlorine, fluorine, sodium, potassium, and rubidium were …
A Comparison Of Analytical And Experimental Approaches In Determining The Thermoelastic Stresses Around A Cylindrical Inclusion Of Elliptical Cross-Section, Kenneth Byron Oster
A Comparison Of Analytical And Experimental Approaches In Determining The Thermoelastic Stresses Around A Cylindrical Inclusion Of Elliptical Cross-Section, Kenneth Byron Oster
Masters Theses
"Three approaches are used to determine the principal stress differences in an infinite elastic medium containing a cylindrical inclusion of elliptic cross-section due to a uniform temperature change. First, the two-dimensional equations of thermoelasticity are solved resulting in equations for the stress components anywhere in the medium material. Second, boundary displacements based on stress-strain relations are used as input displacements in a finite element program of the medium. Third, these same boundary displacements are used as input displacements on a photoelastic model simulating the medium. The problem is treated as one of plane strain in the first approach and one …
Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd
Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd
Masters Theses
"The required synchronization of a dynamic crossed-field photomultiplier tube (DCFP) is accomplished by means of a phase-locked loop for which the salient feature is the use of the DCFP as the phase detector. This action is necessitated due to the unique sampling and phase focusing type of operation of the DCFP. The phase-locked loop is implemented by dithering the phase of the synchronizing RF drive signal, bandpass filtering the output pulses of the DCFP and using a synchronous detector at the dither frequency to determine the phase relationship between the incoming mode-locked laser pulses and the RF drive signal. The …
A Study Of The System Lithia - Silica, Roy Richard Ramey
A Study Of The System Lithia - Silica, Roy Richard Ramey
Masters Theses
"X-ray intensity and d-spacing measurements were performed upon samples in the system Li₂O-SiO₂. Samples ranged from 0.0 to 28.0 mole percent lithia and were fired for 72 hours at temperatures from 920ºC to 1400ºC. Atomic absorption analyses were made upon the fired samples. Non-equilibrium conditions were prevalent and results are inclusive. Quartz is the stable phase in the high silica field at temperatures below 1050ºC with cristobalite stable above that. The quartz - cristobalite transformation occurs at 950ºC with the cristobalite transforming into tridymite at 1010ºC. There was wide scattering of data at 1000ºC and below. There was no correlation …
A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney
A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney
Masters Theses
"Three methods for optimizing a proportional and a proportional-integral controller parameter problem were investigated on an iterative analog computer. The three methods were the parameter-perturbation correlation method, the absolute biasing method, and the variable step size method. The process controlled was third order linear. The performance function used to judge the quality of the controller was the time integral of the absolute value of error. All three methods required a trial and error adjustment of the parameters used in these methods. The optimum solution was obtained by all methods. The absolute biasing method, for both the proportional and the proportional-integral …
Wind Tunnel Modeling Of The Atmospheric Boundary Layer, Sreemanth Pagadala
Wind Tunnel Modeling Of The Atmospheric Boundary Layer, Sreemanth Pagadala
Masters Theses
"The importance of simulating atmospheric flows in wind tunnels has been well established. Experiments were conducted in the Modified Aerodynamic Wind Tunnel to determine the suitability of this wind tunnel for simulating atmospheric flows and the degree to which various aspects of modeling could be fulfilled. A temperature profile to simulate the inversion aloft was generated inside the test section, and then an appropriate velocity profile was built in by means of screen mesh arrangements. The turbulence characteristics of the flow were measured. The validity of the temperature, velocity and turbulence fields were examined. It was found that while the …
The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer
The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer
Masters Theses
"The general theory of large elastic deformations is applied to the problem of a liquid-filled, axisymmetric membrane which is supported on a rigid horizontal plane and subjected to a variable external pressure. The variable external pressure is caused by submerging the membrane to various depths. The variation of the hydrostatic pressure in the inflating medium as well as in the surrounding environment is considered. By assuming large meridional deformations the stress field and the deformed shapes of a submerged membrane made of a neo-Hookean material are obtained. The effect of the initial shape on the deformed configuration of the membrane …
Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang
Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang
Masters Theses
"By precise X-ray measurements, the lattice parameter of pure nickel (Fisher Co., reagent grade) was found to be 3.52389 Å at 25ºC. At the same temperature, the lattice parameters of iron samples were found to be: 2.86621 Å, 2.86624 Å and 2.86614 Å for purities of 99.999%, 99.985% and 99.9%, respectively. By measuring high angle back reflection lines, the linear coefficients of thermal expansion of both nickel and iron were precisely determined. Both, high purity nickel and iron, exhibited anomalies in their expansion coefficients near their Curie points. This is in agreement with some of the previously reported data. Some …
Investigation Of A New Type Of Cloud Condensation Nuclei Counter: The Thermal Quench Chamber, Donald Arthur Hess
Investigation Of A New Type Of Cloud Condensation Nuclei Counter: The Thermal Quench Chamber, Donald Arthur Hess
Masters Theses
"The design and development of a new type of cloud condensation nuclei counter was undertaken to provide a new laboratory and field instrument that operates on a different theoretical basis than the thermal diffusion chamber now being used by meteorologists and other scientists. In the new instrument the test aerosol is pumped through a tube where it is first humidified and then cooled at constant pressure to create a supersaturation, causing water vapor to condense upon the nuclei in the aerosol sample. The concentration of cloud condensation nuclei is then determined by counting the water drops. The control of temperature …
Transient Cooling Of A Sphere Due To Boiling, Salil K. Banerjee
Transient Cooling Of A Sphere Due To Boiling, Salil K. Banerjee
Masters Theses
"The time - dependent surface temperature is determined for a sphere subjected to cooling by boiling. One dimensional heat transfer is considered and the solid is assumed to be homogeneous, isotropic and opaque to thermal radiation and to have temperature independent physical properties. The initial temperature of the sphere and the coolant are assumed to be uniform and arbitrary. The boiling heat transfer coefficient at the surface of a sphere is a strong function of the surface temperature thus resulting in an extremely nonlinear transient heat conduction problem. As a practical application of the problem, the process of quenching has …
Adsorption And Desorption Of Chlorinated Hydrocarbon Pesticides By Organic Humic Sludge, Fu-Sheng Chien
Adsorption And Desorption Of Chlorinated Hydrocarbon Pesticides By Organic Humic Sludge, Fu-Sheng Chien
Masters Theses
"This research study was undertaken to investigate the fundamental sorption and desorption of selected organic pesticides by organic humic acids under laboratory-controlled conditions. Emphasis was placed on the evaluation of both the rate and the equilibrium of adsorption and desorption. Two types of chlorinated hydrocarbon pesticides were employed in this study. These are dieldrin and heptachlor, both of which are commonly used in today's agricultural applications. The adsorbent of organic humic acids was extracted from a coal-like substance called "leonardite," which has a humus content as high as 53 percent by weight. The experimental work of this study was conducted …
Mechanism Of Ual₃ To Ual₄ Transformation, Ling Ping Lee
Mechanism Of Ual₃ To Ual₄ Transformation, Ling Ping Lee
Masters Theses
"The UAl₄ compound which forms during the peritectic reaction, Liquid + UAl₃ - UAl₄ , has a long needle-like shape and a characteristic morphology of fish-tail when cut along the long axis. It has an internal core of another phase when cut perpendicular to the needle axis. Because of the interesting similarity between UAl₃ and UAl₄ crystal structures, the peculiar UAl₄ morphology could be explained. The mechanism of UAl₃ to UAl₄ transformation is identified as shear and diffusion controlled transformation"--Abstract, page ii.
A Practical Approach To The Exhaust Silencing Of A Pneumatic Rock Drill, Morton Gary Barth
A Practical Approach To The Exhaust Silencing Of A Pneumatic Rock Drill, Morton Gary Barth
Masters Theses
"One-third octave spectrum analyses of the exhaust noise produced by a medium sized pneumatic rock drill were obtained during free recriprocation to determine the most troublesome bands of noise. Noise reduction techniques were then used to design exhaust mufflers which would reduce the level of the exhaust noise to an acceptable level with a minimum increase in back pressure. The prototype mufflers evaluated included an expansion chamber, a resonator, and various modified expansion chambers. One of the modified expansion chambers tested provided very good attenuation reducing the exhaust noise from 113 dBA to 87 dBA at the operator's ear position. …