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Articles 73381 - 73410 of 77385

Full-Text Articles in Engineering

The Structural Behavior Of Cold-Formed Steel Members With Perforated Elements, Charles S. Davis Jan 1972

The Structural Behavior Of Cold-Formed Steel Members With Perforated Elements, Charles S. Davis

Doctoral Dissertations

"Analytical and experimental investigations have been conducted to study the influence of perforations on the structural behavior of cold-formed steel structural members. Since in many cases, the load-carrying capacity of cold-formed steel members depends on the buckling behavior of individual component elements, emphasis has been concentrated on the study of the instability and post-buckling strength of perforated elements. In this investigation, the buckling loads and post-buckling strength of stiffened and unstiffened compression elements having single circular and square holes have been studied analytically by using the finite element method. The effects of different holes on the buckling coefficient have been …

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A Mass Spectrometric Characterization Of Positive Ions Created In Simple Vacuum Diodes Incorporating Oxide Cathodes With Supplementary Analysis Of Background Gases, Larry A. Addington Jan 1972

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 …

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Computer Method For Airport Noise Exposure Forecast, John Michael Bateman Jan 1972

Computer Method For Airport Noise Exposure Forecast, John Michael Bateman

Retrospective Theses and Dissertations

The major problem facing air transportation for the next decade is aircraft noise. The noise level due to the operation of large jet aircraft has created a very serious annoyance problem to the people living near of adjacent to jet airports. The noise problem has developed both for take-off and landing operations of these aircraft with take -off noise causing the greatest annoyance factor. A technique called Noise Exposure Forecast (NEF) has been developed to identify the annoyance factor of these noises to people and activities on the ground. With these NEF ratings or numbers, planners can better determine the …

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A Management Training Game For Police Command/Control Officer Training, Charles R. Custer Jan 1972

A Management Training Game For Police Command/Control Officer Training, Charles R. Custer

Retrospective Theses and Dissertations

No abstract provided.

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A Survey Of Simultaneous Binary Multiplication, Joseph Larry Voyer Jan 1972

A Survey Of Simultaneous Binary Multiplication, Joseph Larry Voyer

Retrospective Theses and Dissertations

No abstract provided.

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Decimal-Base Binary Logic (Dbbl) Adders And Registers, James Oliver Bondi Jan 1972

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 …

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Optimization Analysis Of A Simple Position Control System, Arthur G. Cannon Jan 1972

Optimization Analysis Of A Simple Position Control System, Arthur G. Cannon

Retrospective Theses and Dissertations

One of the problem areas of modern optimal control theory is the definition of suitable performance indices. This thesis demonstrates a rational method of establishing a quadratic performance index derived from a desired system model. Specifically, a first order model is used to provide a quadratic performance index for which a second order system is optimized. Extension of the method to higher order systems, while requiring more computations, involves no additional theoretical complexities.

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Flood Control Modeling, Peter E. Delle Donne Jan 1972

Flood Control Modeling, Peter E. Delle Donne

Retrospective Theses and Dissertations

This is a research report that discusses some continuous and discrete modeling techniques. The report applies these techniques to the analysis of Canal 38 (Kissimmee River) part of Central and South Florida Flood Control District. The analysis is based on recorded data for defining the physical systems parameters. Established parameters are mathematically related to define a descriptive model for Canal 38. The modeling procedure of 'trial and error' is used to assemble the model with measures of merit, the integral square error, and root mean squared error. General simulation considerations are discussed for application of the mathematical model.

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Analyses Of The Water And Wastewater Systems At Florida Technological University, Fred C. Jensen Jan 1972

Analyses Of The Water And Wastewater Systems At Florida Technological University, Fred C. Jensen

Retrospective Theses and Dissertations

In searching for a subject to meet the M. S. Degree Research Report requirements, I had several objectives in mind. I wanted (1) a project with relevancy in the environmental field which would broaden my understanding of the environmental systems which I have studied, (2) a subject which would allow me to apply some of the Principles which I have learned in Operations Research , and (3) a project which had good practical application. With these objectives in mind, I reviewed the suggested topics presented by the Faculty and selected the FTU Water and Wastewater System Analyses topic which was …

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Rapid Mixing In Water And Wastewater Treatment, Randall C. Rector Jan 1972

Rapid Mixing In Water And Wastewater Treatment, Randall C. Rector

Retrospective Theses and Dissertations

No abstract provided.

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Interactions Of Pesticides And Phytoplankton, Pamela H. Philyaw Jan 1972

Interactions Of Pesticides And Phytoplankton, Pamela H. Philyaw

Retrospective Theses and Dissertations

No abstract provided.

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Performance Of Self Bit Synchronizers For Binary Overlapping Signals, Chung-Tao David Wang Jan 1972

Performance Of Self Bit Synchronizers For Binary Overlapping Signals, Chung-Tao David Wang

Doctoral Dissertations

"This research is concerned with the optimum and suboptimum ways of providing self bit synchronization for binary overlapping signals. A maximum likelihood synchronizer is derived as the optimum approach. The suboptimum ways are those employing decision-directed feedback and matched derivative filter techniques which are proposed for treating the overlapping signals. Combining the two suboptimum techniques along with the bandlimited version of the overlapping signal, a suboptimum synchronizer is derived. The performance of the above synchronizer is evaluated by Monte Carlo simulation techniques. Finally, a bit synchronizer using nonlinear filtering theory is considered. The performance of a nonlinear bit synchronizer is …

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An Investigation Of Methods For Reuse Of Rubber Tires, Charles Edward Armbruster Jan 1972

An Investigation Of Methods For Reuse Of Rubber Tires, Charles Edward Armbruster

Retrospective Theses and Dissertations

Methods of reusing/recycling the more than 250 million automobile and truck tires which are worn out each year were investigated. The existing methods of reusing tires account for about 30 percent of the volume of scrap tires generated each year. These methods are, Retreading, Reclaiming (by reducing to ground up rubber and fiber), and Tire Splitting (stamp items out of sidewall and tread areas). Several possibilities for reusing/recycling the unused 70 percent were discovered. These methods are as follows: Destructive Distillation -- a method of recovering chemicals from tires by pyrolitic action. It is anticipated that eventually as much as …

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The Relationship Of Textbooks To Development Of Course Content In The Teaching Of Small Gas Engines, Frank Demchuck Jan 1972

The Relationship Of Textbooks To Development Of Course Content In The Teaching Of Small Gas Engines, Frank Demchuck

All Master's Theses

This study compares and evaluates the ideas and opinions of practitioners with the ideas and opinions of educational theorists. Information from the practitioners was gathered by questionnaire. Information from the theorists was gathered by a search of the related literature. The findings, showing the relationship or textbooks to the development of course content in the teaching of small gas engines, are presented and evaluated. A small gas engines textbook outline based on information gained from this study is also presented.

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Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris Jan 1972

Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris

Doctoral Dissertations

"Poly-(p-phenylenepyromellitamic acid)s have been synthesized over the weight average molecular weight range from 8,000 to 22,000 by reaction of pyromellitic dianhydride and p-phenylenediamine in dimethylformamide. The polymers were recovered as amorphous yellow powders having planar dimensions of 3-4 x 1-2 µm with thicknesses of 0.1-0.2 µm and contained 20-30% associated dimethylformamide. Consumption of reactants and attainment of the ultimate molecular weight of the polymer was found to occur within one minute. Thermogravimetry of the solid poly(amic acid)s was used in a method developed to determine the amount of associated dimethylformamide, to study the cyclization of poly(amic acid) to polyimide, and …

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Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds Jan 1972

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 …

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An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja Jan 1972

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 …

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Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang Jan 1972

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 …

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A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah Jan 1972

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.

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The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel Jan 1972

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 …

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A Comparison Of Analytical And Experimental Approaches In Determining The Thermoelastic Stresses Around A Cylindrical Inclusion Of Elliptical Cross-Section, Kenneth Byron Oster Jan 1972

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 …

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Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd Jan 1972

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 …

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A Study Of The System Lithia - Silica, Roy Richard Ramey Jan 1972

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 …

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A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney Jan 1972

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 …

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The Analysis Of An Axially Symmetric Submerged Membrane Shell, Walter Earl Wehmeyer Jan 1972

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 …

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Thermal Expansion Of Nickel And Iron, And The Influence Of Nitrogen On The Lattice Parameter Of Iron At The Curie Temperature, Jinn-Wen Hwang Jan 1972

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 …

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Investigation Of A New Type Of Cloud Condensation Nuclei Counter: The Thermal Quench Chamber, Donald Arthur Hess Jan 1972

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 …

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Transient Cooling Of A Sphere Due To Boiling, Salil K. Banerjee Jan 1972

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 …

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A Practical Approach To The Exhaust Silencing Of A Pneumatic Rock Drill, Morton Gary Barth Jan 1972

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. …

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Use Of Isotopes To Reduce Neutron-Induced Radioactivity And Augment Thermal Quality Of The Environment Of An Underground Nuclear Explosion, Nathaniel Fred Colby Jan 1972

Use Of Isotopes To Reduce Neutron-Induced Radioactivity And Augment Thermal Quality Of The Environment Of An Underground Nuclear Explosion, Nathaniel Fred Colby

Masters Theses

"The use of isotopes to include radioactive waste products to reduce the neutron-induced activity of an underground nuclear explosion and its application in the field of geothermal power stimulation is discussed. A shield composed of selected isotopes surrounding a fusion device will capture excess neutrons producing isotopes with short half-lives. Subsequent rapid decay will prolong the high temperature in the vicinity of the explosion and decrease the activity. Long-lived isotopes created by neutron capture in the host rock would be minimized. The investigation is conducted for strontium-90, cesium-137, cerium-144, technetium-99, rhodium-103 and -105. Of these, the first three appear to …

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