Digital Commons Network^™

Rock Fragmentation By Subsurface Thermal Inclusions - A Finite Element Study, Mahendrakumar Ramkrishna Patel

Doctoral Dissertations

"Although rock tunneling machines are being used extensively with performance and cost advantages over traditional drill and blast methods, their usefulness for hard rock excavation is far from being practical due mainly to the inability of present day mechanical cutters to penetrate these rocks economically. Among various novel techniques that are being investigated, internal heating methods seem to be the most promising. This investigation is concerned with a feasibility study of thermal rock fragmentation using heat to create in-depth thermal inclusions.

The three-dimensional problem of in situ rock fragmentation involves parallel rows of equidistant holes drilled to a constant depth. …

Paleozoic Stratigraphy As An Ore Control Of Hydrothermal, Base-Metal, Sulfide Deposits In New Mexico, John Samuel Sullivan Jr.

Doctoral Dissertations

"Until now the concept or regional stratigraphic control of hydrothermal ore deposits has not received much attention in the literature as a possible exploration guide for locating additional ore bodies. This concept is applied on a regional scale to Paleozoic strata in thirteen mining districts with hydrothermal base-metal deposits in a 35,300 square mile area or southwest New Mexico.

The rocks at the stratigraphic position of the ore-zones are characterized as massive- to thick-bedded with less than 5 percent chert present. The rocks are abundantly to moderately fractured. Fine- to medium-grained dolomite is the dominant host-rock in the lower Paleozoic …

Petrography, Chemical Composition, And Stratigraphic Setting Of The Coals Of North-Central Missouri, William Keith Wedge

Doctoral Dissertations

"Under a grant from the National Air Pollution Control Administration, the Missouri Geological Survey undertook a core drilling program to learn more about the coals in north-central Missouri. The stratigraphic setting and chemical and petrographic characteristics of 43 complete samples of coal recovered from 13 diamond drill holes in the exploration program in north-central Missouri are major contributions of this study. These samples represent twelve different coal beds of the Atokan and Desmoinesian Series of the Pennsylvanian System of Missouri and range in thickness from 9.6 to 44.4 inches. They have an average thickness of 20.4 inches and a combined …

Flowware -- A Flow Charting Method To Describe Digital Systems, Wayne Everett Omohundro

Doctoral Dissertations

"FLOWWARE is an interactive, graphical language to aid in the understanding and design of digital networks. The language is based upon the concept of flow charting. The user specifies the register layout of the system and the sequential operation in the form of a diagram on a graphics terminal. FLOWWARE makes full use of a local minicomputer to perform editing and drawing functions, and a remote large computer to perform translation and simulation. This division of labor allows the user to build his description off-line without having the remote computer program active"--Abstract, page ii.

Numerical Simulation Of Individual Wells In A Field Simulation Model, Ali Mohammed Akbar

Doctoral Dissertations

"Conventional numerical simulation of hydrocarbon reservoirs is inadequate for the prediction of bottom-hole pressures at production wells. This problem can be overcome by using a special mathematical model which combines individual well simulation with reservoir simulation. Severe computational instability is commonly encountered in the radial models due to the relatively small grid-blocks and high fluid velocities in the vicinity of the well bore. This instability is found to be more pronounced during depletion of the reservoir when the pressure near the well bore is below bubble-point pressure. A new technique is introduced here for saturation calculations in the critical region …

Applications Of Frequency Domain Stability Criteria In The Design Of Nonlinear Feedback Systems, Allen Joseph Rushing

Doctoral Dissertations

"The Popov criterion for absolute stability of nonlinear feedback systems is applied to several example problems. Model transformations such as pole shifting and zero shifting extend the class of systems to which the criterion applies. Extensions of the criterion having simple graphical interpretations yield stronger results for systems with constant monotonic slope-bounded nonlinearities. Additional extensions lacking simple graphical interpretations in the complex plane are also demonstrated by example.

Stability throughout a region in parameter space is discussed, and the Kalman conjecture is verified for a new class of systems. The Popov criterion is also used to prove BIBO stability, process …

Considerations In The Design Of A Network Of Minicomputers, Hardy J. Pottinger

Doctoral Dissertations

"The advantages of a network consisting of a number of minicomputers coupled to a large time shared computer are described. This type of network is very useful in the areas of data acquisition, real time control of experiments, and front-end processing for computer graphics.

Problems associated with the development of a network of this type, various possible solutions, and the trade-offs involved are presented. These problems are classified into two categories: the interface between the network and the central computing facility, and the interface between the remote sites and the rest of the network.

The design constraints, rationale, and implementation …

Implementation Of Recursive Algorithms For Delay-Time Estimation Using The Fast Walsh Transform, Donald Robert Nelson

Doctoral Dissertations

"Use of the fast Walsh transform to resolve noisy signals into Walsh function series to digitally implement maximum-likelihood parameter estimators for real-time use is investigated. Realization of estimators which seek a null in the derivative of the log-likelihood function, instead of direct maximization, results in feedback algorithms which yield considerable savings in computation time and storage. Performance of these feedback delay-estimation algorithms is characterized in terms of mean-squared error (MSE) and response to a delay step by Monte Carlo simulation. The effect of changing the number of points in the transform on the MSE is also investigated. Hard limiting of …

Measurement Of Molecular Diffusivities Of Liquid Alkane Systems, James W. Moore

Doctoral Dissertations

"An unsteady-state porous frit method of diffusion coefficient measurement, recently developed in this laboratory, was improved and expanded upon. The experimental technique has been refined and documented. The unsteady-state diffusion of an initially 0.5 N NaCl solution into pure water (effective diffusivity -1.480 x 10^-5 cm²/sec) was employed as the calibration standard. An overall calibration precision of ±4% was obtained. Diffusion times of two hours or less were used for the non-aqueous diffusivity measurements. The validity of this measurement technique was confirmed by the agreement of the measured self-diffusion coefficient of n-heptane (25⁰C) with literature values.

A …

Premartensitic Elasticity Of Fe-Ni Invars, Bryce Linn Shriver

Doctoral Dissertations

"The premartensitic temperature dependence of ultrasonic wave propagation in Fe-30 pct Ni polycrystals and Fe-32 pct Ni single crystals was measured by using a continuous wave technique. As the temperature was lowered to within 10°C of the M_s, a nonlinear decrease of the relative shear velocity was observed. This effect is related to dislocation stacking fault instabilities which may trigger the martensitic phase transformation. In addition, the single crystals show a frequency dependence of the shear elastic constant C' well above the M_s. The dispersion is believed to be caused by fluctuations in the anisotropic molecular …

Hall Effect Measurements Of The Net Ionic Mobility In Nacl, Nabr And Nai, Suman Kumar Hukku

Doctoral Dissertations

"Ac Hall effect measurements of the net ionic mobility, µ_H, in "pure" NaCl, NaBr and Nal were made over their intrinsic temperature ranges extending up to about 250⁰ C below the crystal melting point. A well characterized detector system was employed which provided a mobility sensitivity ≥ 2 x 10^-4 cm² · V^-1 · s^-1. Complementary electrical conductivity, σ, data was also collected. The charge transport was assumed to be due to Schottky defects and both cation and anion contributions were considered. The high temperature anion contribution to mobility was clearly demonstrated by …

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 …

The Morphology Of Cellular Precipitation In Aluminum Rich Aluminum-Silver Alloys, Santiago Ibarra Jr.

Doctoral Dissertations

"The morphology of cellular precipitation in Al-29.8wt%Ag alloy has been investigated in bulk specimens by transmission electron microscopy and in solution treated specimens by means of hot stage microscopy. Both cellular and general precipitation were observed to occur simultaneously in quench-aged and isothermally aged alloys. By studying the early stages of precipitation in the hot stage, the mechanism for the growth of cells in Al-Ag alloys was developed. According to this mechanism, the grain boundary allotriomorphs begin to form, the boundary then interacts with the allotriomorphs by bowing, and then either trailing precipitation forms on the allotriomorphs or new lamellae …

A Learning Receiver For Communication In Three-Component Multipath Channels, Richard Paul Brueggemann

Doctoral Dissertations

"An adaptive receiver is designed for transmissions through a time-varying multipath channel which may include both specular and diffuse components. The design is based on the theory of unsupervised learning machines and the receiver is a recursive structure which does not grow in complexity with each new observation, but is Bayes' optimal at each instant of time. The multipath medium is modelled as an aggregate of L conditionally independent transmission paths, each consisting of random and/or fixed reflections, and is identified in terms of three components: (1) indirect diffuse scatter, (2) indirect specular reflection, and (3) direct transmission. The channel …

The Effect And Compensation Of Time-Base Perturbations In Analog Recording Systems, Clifford D. Skouby

Doctoral Dissertations

"The mean square error between recorded and reproduced signals is used as an error measure to determine the effects of time-base perturbations on an analog singal. The mean square error caused by time-base perturbations is shown to be proportional to the product of the square of the signal bandwidth and the time-base error variance for the case of low pass signal. When the signal is band pass, there is shown to be an additional error term which is proportional to the square of the signal center frequency and the time-base error variance.

Calculations are also carried out to determine the …

Trend Surface Analysis As An Aid In Exploration For Mississippi Valley Type Ore Deposits, John Siegfried Trapp

Doctoral Dissertations

"The conditions necessary for emplacement of Mississippi Valley-type mineral deposits can be expressed using mathematical symbols as a function of the pre-depositional topography of the host formation and post-depositional structure. These conditions can be observed and analyzed in the Missouri region from residual maps of trend surface analysis of the Precambrian surface. In areas where the topography prior to deposition of the ore bearing horizon has been strongly altered by the deposition of the basal Paleozoic formation the Lamotte Formation residual maps from trend surface analysis of the top of the Lamotte better illustrate these conditions. The Lamotte Formation in …

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 …

Mechanistic Studies Of The Reaction Of Phenylcadmium Reagent With Alpha-Bromo Esters, Samuel Joseph Costanzo

Doctoral Dissertations

No abstract provided.

Studies On The Quantitative Enumeration Of Viruses In Water, Frederick Carlton Pearson Iii.

Doctoral Dissertations

No abstract provided.

Probabilistic Models For Construction Estimating And Bidding, James E. Spooner

Doctoral Dissertations

"Two probabilistic models are offered as a means for quantitatively determining contingency in a lump-sum bid. The first model is based on the isolated project and requires subjective evaluation of probabilities associated with the individual elements of the estimate. Contingency is defined as a function of the standard deviation of project field costs. Procedures are developed to obtain the variance of the total field cost from three-value estimates of the primary quantities. The second model considers the business as a stochastic process with an initial risk reserve and a positive risk loading, and contingency in this model is a function …

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 …

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 …

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 …

A Method For Generating Uts Assignments With An Iterative State Transition Algorithm, Dattatraya Govind Raj-Karne

Doctoral Dissertations

"There is a lack of systematic procedures that can be used to find uni-code totally sequential (UTS) assignments from a flow table description of an asynchronous sequential circuit. Presented here is an iterative internal state assignment method. This method consists of three algorithms. The first generates a minimum variable initial assignment from a flow table description. The second tests the validity of this assignment by constructing minimum length transition paths without crossover and the third augments this assignment by adding an internal state variable in the event that all transition paths cannot be constructed without crossover. The second and the …

Stratigraphy, Genesis, And Economic Potential Of The Southern Part Of The Florida Land-Pebble Phosphate Field, Dean Stanley Clark

Doctoral Dissertations

"The important and highly productive Florida land-pebble phosphate field is located in west central peninsular Florida in portions of Hillsborough, Polk, Hardee, and Manatee counties. The Pine Level phosphate area, described in detail in this report, is south of the previously known and mined deposits and occurs in portions of Manatee, Sarasota, and De Soto counties. Results of the current geologic study of the Pine Level phosphate deposit and the evaluation of the overall potential of this southern part of the land-pebble field are presented.

The entire southern part of the phosphate field is underlain by more than 15,000 feet …

Distributed-Network Realizations For The Simulation Of Partial Differential Equations, Roy Dale Hensley

Doctoral Dissertations

"A method is developed for the simulation of the partial differential equation

-u_xx + k_ou_tt + k_lu_t +k₂u = g(t)

for various boundary conditions. The boundary conditions are used to classify the problems into types and the Laplace transformed solution of the most general problem of each type is obtained.

Synthesis techniques are presented for the realization of circuits containing distributed networks that can be used to simulate the partial differential equation for given boundary conditions. Several heat flow and vibrating string examples are included to illustrate the application of the …

The Mio-Eugeosynclinal Thrust Interface And Related Petroleum Implications In The Sason-Baykan Area, Southeast Turkey, Ismail Özkaya

Doctoral Dissertations

"A detailed investigation of the stratigraphy, structure and petroleum geology of the Sason-Baykan region in 600 square km area of the thrust belt of southeast Turkey was completed at a scale 1: 25 000. Geosynclinal sediments within the area were redated.

Results of field study indicate a massive plate of metamorphic rocks and crystalline limestones was thrust southward over geosynclinals sediments. These in turn were thrust over the southern marginal basin deposits. A stratigraphic sequence of the allochthonous geosynclinals sediments was reconstructed and correlated with the autochthonous Tertiary section. Contrary to earlier views the allochthonous sediments and accompanying igneous rocks …

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 …

Computer Assisted Teaching Of Steel Design, Wendelin Henry Mueller Iii

Doctoral Dissertations

"A method for use in creating a university level course is presented. The specifics of each of the steps is given in general terms to allow its application to as many different topics as possible. This method is then specifically applied in the formation of a fundamental steel design course using the American Institute of Steel Construction Specification. The reasoning utilized in each phase of development is documented. A lecture style presentation complemented by a series of student oriented computer programs was chosen for use. The details of the course material in outline form is given along with the computer …

Wall Rock Geochemistry Of The Chester Vein, Sunshine Mine, Kellogg, Idaho, Nicholas Howard Tibbs

Doctoral Dissertations

"The Chester vein has been the major source of ore from the Sunshine mine, largest single producer of silver in the world. 425 samples of quartzite and argillite wall rocks were collected in 13 traverses across this vein on the 4400, 4600, and 4800 mining levels. These samples were analyzed for aluminum, magnesium, calcium, sodium, potassium, manganese, iron, lead, copper, and zinc by atomic absorption spectroscopy, and for silicon and sulfur by x-ray emission spectroscopy. Element distribution plots, linear correlation coefficient matrices, varimax factor analysis, and cluster analysis were employed to determine the geochemical processes that occurred in the wall …