Digital Commons Network^™

A Study Of Plane Wave Filter Analysis With Flow, Thomas Valle Huber

Masters Theses

"The purpose of this investigation is to determine the effect of slow steady flow on the reflection and transmission characteristics of acoustic filters.

A standing wave tube and transmission tube apparatus, designed and built by a previous investigator, was modified to accept slow steady flow. Reflection characteristics were determined from measurements made on the inlet side of the filters investigated. These data along with measurements taken with the transmission tube apparatus were used to determine transmission characteristics. The calculations were simplified by terminating the filters anechoically. The filters used in this investigation were an expansion chamber, an automobile type muffler …

High Speed Magnetically Supported Vehicles For Reducing Transportation's Degradations Of The Environment, Pravinchandra Shukla

Masters Theses

"The development of new techniques for higher speed transportation is desirable to satisfy the environmental, conservation, and economic requirements of society. Some of the important factors are presented for developing magnetically supported vehicles. A new method for improving the ratio of lift force to drag force is suggested and discussed. An application of the new technique to vehicles that would ride on a carpet of magnetism and would operate with less waste of energy is suggested "--Abstract, page ii.

Drag Reduction On Non-Ionic Surfactants In Aqueous Systems, Jen-Lin Chang

Masters Theses

"The use of polyoxyethylene alcohol non-ionic surfactants as drag reducing additives in aqueous systems was investigated. Significant drag reduction was obtained with suitable combinations of one percent Alfonic 1214 and salts at 30°C such that the surfactant was near or above its upper critical solubility temperature. Maximum drag reduction was observed at the cloud point. Relative viscosity values also peaked at this point. No upper critical shear stress was attained up to wall shear stresses of 2,000 dynes/cm² with one percent Alfonic 1214 solutions at their cloud points.

At a fixed temperature, the salt concentration required to reach the …

Digital Registration Of Stereo Images Using The Fast Fourier Transform, Victor Francis Wilreker Jr.

Masters Theses

"The exact alignment of multispectral imagery is a requirement of any image classification system. This investigation develops a system of programs which result in a technique that corrects for the translational and rotational misalignment of two images. Rotational and translational components are determined by using the fast Fourier transform to find the points of maximum correlation between the two images. The registration of two equal but misaligned boxes is given as an example of how the transform technique is used in correlating the images. The results of registering two digitized images that were obtained by scanning a pair of color …

The Morphology Of The Cellular Precipitation Reaction In A Pb-3.0 Wt% Sn Alloy, Federico Sequeda Osorio

Masters Theses

"The complete development of the cellular precipitation structure at selected grain boundaries in a Pb-3.0 wt% Sn alloy during aging at 34°C and 23°C was investigated by light microscopy. The cellular structure in this alloy consists of lamellae of solute depleted lead solid solution and lamellae of ß tin precipitate. The cellular precipitation reaction begins by local migration of a grain boundary with concomitant grain boundary precipitation of ß tin. The grain boundary bows around the ß tin grain boundary precipitates which then begin to lengthen in the direction of boundary migration thus forming the precipitate lamellae of the cell. …

Computer-Aided Circuit Optimization Including The Adjoint Method Of Calculating Network Sensitivities, John Walter Olson

Masters Theses

"A complete discuss ion of the optimization of a circuit, including modeling and programming difficulties encountered, is presented. A three transistor bandpass filter is used in order to study various methods of optimization. The adjoint method of calculating the network error gradient vector is compared to the perturbation method. The adjoint method proves to have decided advantages over the other method. A generalized computer program is presented to carry out the Fletcher-Powell optimization algorithm with specialized subroutines which include a network equation solver and both methods of finding the gradient vector. The program proved very effective in realizing a desired …

Polynary Silicon Tellurium Glasses, Henry Edward Anthonis

Masters Theses

"The introduction of Ag into Si-As-Te glasses permits the incorporation of Se, otherwise volatile and/or degradable as a constituent in Si-containing chalcogenide glasses. Si-As-Ag-Te-Se glasses exhibit much higher softening ranges and glass transition temperatures than encountered in known chalcogenide systems. A glass Si₃₅As₁₅Ag₁₀Te₂₀Se₂₀ had the viscosity log η =13 at about 500°C, as compared to 370°C for the base glass Si₃₅As₂₅Te₄₀, the viscosity of log η = 9.8 at about 560°C, as compared to 442°C for the base glass Si₃₅As₂₅Te_{40 …}

Laboratory Studies Using Diffused Oxygen And Air For Hypolimnion Reaeration, Chin-Ming Pai

Masters Theses

"The purposes of this research were to study the oxygen transfer rates and the oxygen transfer efficiencies of different types of aerators using different sources of oxygen in different types of water bodies, and to evaluate the number of diffusers required to be installed in a selected lake for hypolimnion aeration.

The experiments were conducted using a specially designed column. Four types of aerators, including a cylindrical stone diffuser, a spherical stone diffuser, and 2 ceramic diffusers (types A and B) which differed in pore size, were utilized as the aerators. The water bodies selected for the studies were Rolla …

Effect Of Glass Aggregates Upon Abrasiveness Of Asphaltic Mixtures, Dwarka Prasad Gupta

Masters Theses

"The utilization of glass as an aggregate in asphaltic concrete pavements has been suggested as a means for reusing the increasing amounts of waste glass generated each year in the United States. Recent studies have shown that asphaltic mixtures containing glass aggregates can be designed to meet Marshall requirements for stability, flow and void content but the abrasiveness of mixtures containing glass aggregates had not been investigated. The objectives of this study were to develop a laboratory wear testing apparatus and compare the abrasiveness of asphaltic concrete mixtures using glass aggregates with the abrasiveness of mixtures using several different conventional …

A Study Of The Effect Of Drilled Holes On The Concentration Of Elastic Stresses Around A Notch, Glenn Michael Kmecz

Masters Theses

"Hole drilling as a method for improving the toughness of notch weakened tensile specimens is investigated by means of a photoelastic technique. Tests were performed on 20%, 40%, 60%, and 80% notch depth specimens machined from PSM-1 photoelastic material. The basic criteria for success was no increase in the elastic stress concentration factor. The photoelastic results were verified by a finite element stress analysis of the 60% notch depth specimens. Comparison of the experimental and numerical results provide conclusive proof that no increase in the elastic stress concentration factor occurs when proper positioning of the drilled holes is accomplished"--Abstract, page …

Design And Construction Of A Drop Generator For Use In A Vertical Wind Tunnel, Danny Ray Conner

Masters Theses

"A drop generator, based on the principle of a vibrating capillary, was designed and built for use in the UMR vertical atmosphere wind tunnel. The drop generator worked very well on a test stand where it was firmly supported, but was not consistent when tested in the wind tunnel. Vibration of the wind tunnel walls and a slight turbulence near the forward edge of the generator caused an oscillation in the position of the stream of drops. The oscillation resulted in some of the drops hitting the edge of the collector cup, where the drops would accumulate until a large …

A Study Of Right Turn On Red At Signalized Intersections, Ronald Duane Rains

Masters Theses

"Traffic engineers have discussed the controversial subject of allowing drivers to make a right-turn-on-red (R.T.O.R.) for many years. There have been many strong points given for and against allowing this movement.

Within this paper R.T.O.R. is discussed and conclusions are drawn for a research of literature and questionnaire survey.

Questionnaires were sent to ninety-three cities and all fifty states. Many valuable unwritten facts and opinions were received from the seventy city and thirty-six state traffic engineers that completed and returned the questionnaires.

It was determined that 63.8% of the states replying and 64.3% of the cities are presently utilizing R.T.O.R. …

Sensitivity Analysis In Active Rc Bandpass Circuits, Robert Bentzinger

Masters Theses

"This thesis is concerned with the analysis and cataloguing of sensitivity functions of some selected active RC bandpass networks. The sensitivity functions of primary interest are the sensitivities of the quantities ω_o and Q with respect to changes in the element values of each circuit.

An introduction is provided to give background information on how each circuit is realized. Each circuit is then analyzed and the pertinent sensitivity functions catalogued. Some comments are made as to the approximations which are involved in several of the realizations and the validity of any sensitivity analysis made on these approximate realizations. The …

An Exact Analysis Of Two-Dimensional Radiative Transfer In An Absorbing And Emitting Gray Medium, William F. Breig

Doctoral Dissertations

"The exact formulations for the radiative flux and the emissive power are presented for a two-dimensional, finite, planar, absorbing and emitting, gray medium in radiative equilibrium. Exact expressions are obtained for the medium subjected to the following types of boundary conditions: (1) cosine varying diffuse, (2) cosine varying collimated, (3) constant temperature strip, and (4) the strip illuminated by a uniform collimated flux. The solutions for the physically unrealistic cosine varying models are used to construct the solutions for the more practical finite strip models. The two-dimensional equations are reduced to one-dimensional equations by the method of separation of variables. …

The Effect Of Impurities And Additives On The Electrowinning Of Zinc, Haruhisa Fukubayashi

Doctoral Dissertations

"The effect of various impurities, commonly found in zinc electro-winning solutions, on the surface morphology of deposited zinc was investigated. Individual additions of the impurities Al, Ag, Cd, Co, Cr, Cu, Ge, Mn, Ni, Sb, Sn, Ti, PbO₂ , PbSO₄, and HCl were studied. In a few cases additives of animal glue, gum arabic, and Na₂SiO₃, were used individually or in combination, to determine their effect on the surface structure of the deposited zinc. Comparisons were then made with deposits from a pure electrolyte consisting of H₂SO₄ and Zn⁺², 200 and 65 g/l, respectively. The zinc was deposited on a …

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 …

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 …

Concentration By Sorting : Feasibility Determination By Radial Distribution Analysis, Robert M. Doerr

Masters Theses

"A method was developed for determining certain factors for assessing the feasibility of sorting fragments of an inhomogeneous solid to concentrate a species. These factors are the typical size of zones in which the grade exceeds a selected value, and the recovery potentially achievable by sorting fragments of such size"--Abstract, page iii.

Performance Comparison Of Receivers Designed To Combat Intersymbol Interference Due To Specular Multipath, George H. Smith

Masters Theses

"Bit error probabilities for biphase transmission have been computed for a known two-component multipath channel with a variety of suboptimum receivers. Performance curves are presented for each receiver, and the relative performance is summarized. Degradation due to imperfect channel knowledge is calculated, and the feasibility of countering this interference with these specially designed receivers is discussed"--Abstract, page ii.

Hydro-Thermal Generation Unit Commitment And Dispatch Using A Dynamic Programming Approach, Warren Dean Graham

Doctoral Dissertations

"The problem of thermal unit commitment is solved with dynamic programming. A practical example is given which solves the problem for a six generator system over a one year time span. This long range solution is used with a hydro optimization procedure to give an optimized hydro-thermal unit commitment solution. From this, a worth of hydro value is computed for each month, which may be used in the daily dispatching of thermal units and hydro. Applications of the program are also shown for aiding in generator maintenance scheduling and evaluating purchase power contracts with neighboring utilities. Error analysis is made …

Effects Of Cr-Plating And Environment On The Cracking Of Low Alloy Steels At High Temperatures, Robert C. Tooke

Doctoral Dissertations

"The cracking of low alloy Cr-Mo-V steels under cyclic stress at 1000-1100°C. was studied using a specially designed test apparatus. The results obtained from specimens plated with hard chromium are compared to those of unplated specimens. Tests conducted in gas mixtures of carbon monoxide and carbon dioxide showed that a high CO/CO₂ ratio retards cracking in both plated and unplated specimens. Both external and internal oxidation are used to explain these results. Inherent microcracks in the hard chromium plating promoted cracking in all CO/CO₂ environments. It was also found that these steels are severely embrittled in the presence …

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 …

The Application Of Impact Dampers To Continuous Systems, Ranjit Kumar Roy

Doctoral Dissertations

"A study has been made of the application of impact dampers to two types of continuous systems, a simply supported and a clamped beam. Previous efforts have included the effect of impact dampers on single degree of freedom and other systems with finite numbers of degrees of freedom.

Experimental models were tested in the laboratory and finite element computer programs were developed to calculate response. Results from calculations agree favorably with experimental tests. Further, results from the first few natural modes also compare reasonably with data published on systems with finite number of degrees of freedom.

Curves are presented which …

Deformation And Fracture Of Concrete Under Uniaxial Impact Loading, Esteban Eulogio Miranda

Doctoral Dissertations

"Stress wave propagation and interaction in plain concrete leading up to spall fracture was investigated experimentally with a computer numerical analysis of the bar-geometry axial-impact loading. The critical normal fracture strain energy U and mechanical energy W criteria are proposed for the spatial and time dependence explanation of spallation in concrete. The energy criteria are special cases of a more generalized cumulative damage model of the form:....

Finite-difference analyses of the wave propagation and interactions in the split Hopkinson bar showed that early failure in brittle materials limits the application of the conventional method of analysis because equilibrium in the …

Modal Truncation Of Substructures Used In Vibration Analysis, Suresh Kumar Tolani

Doctoral Dissertations

"The objective of this study is to describe in a unified manner a group of structural dynamics analyses using the substructures technique. An additional effort is to provide a consistent basis for the selection of substructure principal modes as required by this method. Substructure principal mode frequency roots and strain energy are two criteria evaluated for the selection of substructure principal modes. System eigenvalues and system strain energy are investigated for the comparison of results in the principal modes. System strain energy should provide more rational results since it is proportional to the stress times the strain in the system …

An Asynchronous Circuit Design Language System, Gregory Martin Bednar

Doctoral Dissertations

"This paper presents a system for specifying the behavior of asynchronous sequential circuits. The system consists of a special purpose Asynchronous Circuit Design Language (ACDL), a translator and a flow table generation algorithm. The language includes many special features which permit quick and precise specification of terminal behavior. It is best suited for problems originating from a word description of the circuit's operation. The translator is written with the XPL Translator Writing System and is a syntax-directed compilation method. From the translated ACDL specifications, the flow table algorithm generates a primitive flow table which is the required input for the …

Determination Of Thermal Contact Resistance Between Metals Using A Pulse Technique, William Edward Stewart Jr.

Doctoral Dissertations

"This dissertation reports the results of an experimental and analytical investigation to determine the thermal contact resistance of several metal specimen pairs using a relatively new pulse technique. Metal specimens were aluminum 2024-T3, aluminum 6061-T6, aluminum 7075-T6, copper 110, stainless steel 304, molybdenum, and Armco iron. Thermal contact resistance was also determined for dissimilar metal specimen pairs of aluminum 6061-T6 - copper 110 and aluminum 7075-T6 - copper 110. Aluminum 7075-T6, copper 110, and stainless steel 304 specimens were tested to determine the variance of contact resistance with time after loading.

Specimens were circular cylindrical disks between .033 and .061 …

Digital Spectrum Analyzer Systems: A Model And System Implementation, Richard Ray Kuenzer

Doctoral Dissertations

"This thesis introduces digital spectrum analyzer systems and presents a generalized model which can be used to implement new systems. The model is presented using the Digital Design Language (DDL) to facilitate system programming. Three hardware systems are defined and their merits are considered. Procedures are given to aid in implementing an analyzer system on a wide range of hardware configurations. A digital spectrum analyzer system which was implemented at the University of Missouri - Rolla and is presently being used by electrical engineering students is presented. This system utilizes the IBM 360/SO computer located in the Computer Center at …

Mass Transfer With Second-Order Chemical Reaction Inside Circulating Fluid Droplets, Roy James Brunson

Doctoral Dissertations

"The solution of a mathematical model is presented which describes mass transfer accompanied by a second-order chemical reaction inside a circulating, fluid sphere for the laminar flow region. The values for eight different mass transfer indices are presented as a function of the Peclet number, reaction number, diffusivity ratio, concentration ratio, and the dimensionless contact time. The results of this work are compared with the film and penetration theories for mass transfer with reaction as modified to apply inside a fluid sphere. This work corrects the three factors which limit the accuracy of applying previous theories to fluid spheres: geometrical …

Grain Boundary Diffusion In Ionic Crystals, Kulwant Singh Sabharwal

Doctoral Dissertations

"The diffusion of ¹³¹I in single crystals and along the tilt grain boundaries of pure and calcium chloride doped (142±5 ppm) bicrystals of sodium chloride, grown by Czochralski technique, was investigated using a microtome sectioning technique. Results on bulk diffusion in pure NaCl agree well with the results of earlier investigators and are represented by the D=(504 cm²/sec)exp (-2.27 ev/kT). Enhanced diffusion of ¹³¹I is observed along the grain boundaries and the presence of the dopant lowers the grain boundary diffusivity over the entire temperature range of 430ºC - 570ºC studied in the present investigation. Thermal activation and electrical polarization …