Digital Commons Network^™

A Digital Dynamic Data Compensation Technique, George Lee Schulz

Mechanical Engineering ETDs

The output of seismic transducers is proportional to the input only for inputs in specific frequency range. This paper presents a method for extending the usable frequency range of seismic transducers through the use of a digital data processing technique. The method is based on the assumptions that a seismic transducer may be represented by a damped single degree of freedom system and that the output of the transducer is proportional to the relative displacement between the seismic mass and the surface on which the transducer is mounted. The computational technique utilizes a new, efficient, and accurate method of numerical …

A Criterion For Dynamic Low-Cycle Shear Fracture, Teh T. Liu

Mechanical Engineering ETDs

The present investigation establishes a cumulative-damage criterion for specimens subjected to reversed cyclic dynamic shear loads. The empirical equation is found to be:

where

= the change in plastic shear strain at each loading.

= the ultimate shear strain at single loading.

= the empirical exponent to be determined.

Specimens of 6061-T6 aluminum alloy were tested under reversed shear loadings from 1 to 22 applications prior to fracture. The amount of shear deformations was measured at the center part of the critical section. The data was analyzed with the aid of a digital computer. The exponent p in the power …

Further Investigation Of Light Gage Steel Forms As Reinforcement For Concrete Slabs, C. E. Ekberg Jr., R. M. Schuster, Max L. Porter

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Three-Bolt In-Line Connections With Low Ductility Light-Gage Steel, D. W. Popowich, S. J. Errera, George Winter

CCFSS Library (1939 - present)

INTRODUCTION In order to investigate the influence of ductility on the strength and behavior of bolted connections, Dhallal (1) conducted tests on single bolt lap joints using "low ductility" steels. As part of a separate investigation, Popowich (2) conducted tests on single, double, and triple bolt in-line lap joints using "high ductility" steels. The investigation reported herein was performed in order to compare the performance of 3 bolt in-line connections of high ductility steels (21 to 53% elongation in a 2 inch gage length) with that of similar 3 bolt in-line connections of low ductility steels (nominally 5 and 10% …

Australian Tractor Test Report No. 54 : Fiat 615, G H. Vasey, W. F. Baillie

Journal of the Department of Agriculture, Western Australia, Series 4

AUSTRALIAN TRACTOR TEST REPORT

No. 54 - FIAT 615

The tractor is designed for working either with mounted implements directly through the three-point linkage or through the drawbar.

Comparison Of Lagrangian Time Correlations Obtained From Dispersion Experiments And From Space‐Time Correlation Functions, J. M. Rodriguez, Gary Kent Patterson

Chemical and Biochemical Engineering Faculty Research & Creative Works

No Abstracts. Copyright © 1969 American Institute of Chemical Engineers

Structure Of Shock Waves With Nonequilibrium Radiation And Ionization, Harlan F. Nelson, R. Goulard

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The investigations of this study are concerned with: (1) the physical processes that occur in the precursor and in the nonequilibrium region behind a strong shock wave during its approach to equilibrium in an argon like gas; (2) the influence of different atom-atom collisional rates in the relaxation region on the precursor; and (3) the cause of precursor ionization, which in this study has been assumed to be the photoionization of both the ground and excited states. The argon like gas is regarded as a combination of two gases: one consisting of electrons and the other of atoms and ions. …

Numerical Simulation Of Pressures In A Radical System, Vijender Nath Gopal

Masters Theses

"The time-space location of an advancing front has been described in such a manner as to permit the calculation of frontal pressures when a heterogeneous (in permeability) radial system is subjected to water encroachment. A finite difference application has been developed to calculate these pressures at specified radial distances from the injection or production wellbore. These pressure have been further utilized to predict the pressures at the advancing front for different time intervals"--Abstract, page iii.

A Computerized Method For Finding The Dynamic Response Of Multi-Mass Systems With Damping To Arbitrary Inputs, Bakulesh Balbhadra Patel

Masters Theses

"A practical procedure for the systematic application of Foss's method to the solution of multi-degree-of-freedom damped systems is presented. It is relatively easy to determine the response of classically damped systems to various inputs. For non-classically damped systems the method proposed by K. A. Foss has been employed. This method gives an exact and complete solution for the response of linear multi-mass damped systems subjected to arbitrary inputs. Since the method requires lengthy and complex computations, the use of a digital computer is essential. In order to obtain the complete response of a multi-mass damped system to both sinusoidal and …

Vibration Of An Internally Damped Tapered Truncated Cantilever Beam, Chimanbhai Magandas Patel

Masters Theses

"This thesis provides a vibration analysis of an internally damped, tapered, truncated, cantilever beam. Using two formulations of the problem based on: (1) Discrete mass and (2) continuous mass distribution, solutions are given for a beam having square cross section with linear depth and linear width variation. A Kelvin viscoelastic material for the beam is assumed. The vibration of the beam is considered to produce plane stress in the material, and the stress-strain relationship is applied only to the strain in the plane of bending. An exact solution for frequency of oscillation, mode shape, and steady state response is obtained …

Neutron Induced Changes To The Modified Ebers-Moll Transistor Model Used In The Net-1 Program, Kenneth Robert Smith

Masters Theses

"The development of theoretical and empirical relations which predict the permanent changes to the electrical characteristics of silicon transistors is described in this paper. Analytical techniques are also developed to obtain the parameters used in the Modified Ebers-Moll transistor model. The method employed is to determine the effects on externally measurable characteristics and to relate these changes to the parameters in the Modified Ebers-Moll transistor model. Further, all nonlinear characteristics are related to the independent variables with interpolating polynomials and degraded characteristics presented. then degraded characteristics are used to establish the parameters for and parameter changes to the transistor model …

A Study Of The Effect Of Tube Bundle Geometry On The Nucleate Boiling Region Of A Series Of Hydrocarbon Liquids, Robert Terry Montgomery

Masters Theses

"The primary purpose of this heat transfer investigation was to determine quantitatively in what manner tube bundle geometry affects the nucleate boiling region of a tube whose single tube boiling characteristics are known. A series of tests were conducted with horizontal tube bundles which produced boiling in a saturated pool of n-hexane, n-pentane, and seven carbon (C₇) hydrocarbon mixture at atmospheric pressure. Tube bundle size and pitch were the principle independent variables considered. The phenomena of heater hysteresis and aging were also studied. Data are presented which indicates that aging probably is not a direct consequence of gas adsorption on …

The Effect Of Aging On The Exfoliation Corrosion Characteristics Of 7178 Aluminum Alloy, J. James Slavick

Masters Theses

"The objective of this investigation was twofold: 1) to determine the effect of the quench-to-artificial aging delay period on the exfoliation corrosion of 7178 aluminum alloy subsequently aged at 250F for 24 hours and 2) to determine the effect of an initial aging treatment at 212F on the tensile properties and exfoliation of 7178 aluminum subsequently aged at 250F. Testing was conducted on 0.125 inch thick sheet. Quench-to-aging delay periods of 0 to 28 days, and initial artificial aging treatments at 212F for 24 and 48 hours were investigated. In addition, the effect of overaging T6 material at 320F for …

Tunnel Diode Models For Electronic Circuit Analysis Program (Ecap), Carmon Dale Thiems

Masters Theses

"In this paper ECAP models for the tunnel diode are presented. Results showing the model, the current-voltage charateristics [sic] are discussed. Operation in typical circuits is presented. A summary of the current state of the art in modeling appears in Appendix I. Since ECAP is only structured to accept piecewise-linear models of these devices, that type of model is presented here. All of the models are developed to approximate the typical tunnel diode current-voltage characteristic"--Introduction, page 1.

A Photoelastic Study Of The Stresses Around An Underground Opening And Its Support System, Alphonse C. Van Besien

Masters Theses

"The stress conditions around openings in rock have long been of interest to the field of rock mechanics. The purpose of this investigation was to determine the stress distribution around an opening with a rib and wall-plate support system. A photoelastic model of the opening (a modified horse-shoe section) was loaded in the centrifuge to determine the effect of body loading. Both the tangential stress and the stress within the rock bench, due to the opening, were determined. The stress conditions within the bench were examined using simulated ribs and a loading frame. Application of the data is discussed, as …

A Study On Load Transfer Of Model Friction Piles, Richard Milton Franke

Masters Theses

"Previous investigations concerned with disturbance of soft clay by driving displacement piles are summarized. The initiation of excess pore water pressures due to pile driving, and mechanisms of load transfer are also described, along with the applicapability of model pile testing in analysis of the various phenomena. Load tests were conducted on assorted sizes of model friction piles embedded in sedimented soil samples with consisted of a silt and clay mixture. Pilot holes of various diameters were cut in the samples. A theoretical load distribution curve was used to calculate the load transferred to the soil as a function of …

Design And Use Of A Universal Logic Circuit, Mahendrakumar Punjalal Shah

Masters Theses

"Yau and Tang have designed universal logic circuits (ULC's) of three variables with 8 I/O pins. They assumed that only one variable was available as a free input variable in its true and complementary form, the others were available as fixed input variables and the circuit generated true and complementary outputs. Their design required 22 I/O pins for a four-variable ULC, constructed from three variables ULCs. This paper decrived [sic] an algorithm for determining the input-pin connections, directly from the K-map of a given output function, for any n-variable ULC. Forslund and Waxman have designed a three-variable ULC using the …

Internal Friction Of Phase Separated Glasses, Scot Walter Taylor

Masters Theses

"The large internal friction peak observed in a 10Li₂O·10Na₂O·80SiO₂ glass was studied as a function of the degree of phase separation. Transmission electron microscopy was used to evaluate the type and degree of phase separation. No observable changes in the temperature position or height of the internal friction peak were observed at successive stages of phase separation. Phase separation of a mixed alkali borosilicate glass also produced no changes in the internal friction peaks. Phase separation is not considered responsible for the large internal friction peak observed in mixed alkali glasses"--Abstract, page ii.

The Effect Of Small Additions Of Niobium Upon The Corrosion Rates And Electrochemical Potentials Of Iron In Hcl, Hf, And H₂So₄, Richard Lee Jones

Masters Theses

"The valence of niobium ions going into solution was determined by dissolving the metal in hot HF and measuring the volume of hydrogen evolved. The corrosion rates of Nb, NbH_x, Fe and Fe - Nb alloys were determined in various concentrations of NCl, H₂SO₄ and HF. The Fe and Fe - Nb alloy samples were made by using powder metallurgy techniques. It was found that a metal skin was produced on the surface of iron corrosion samples if the carbon content of the surface layer was lower than that of the core of the sample. The lower carbon …

Apparatus And Techniques For The Plane Wave Analysis Of Acoustic Filters, Victor Hugo Simon

Masters Theses

"This thesis describes a method for determining the reflection and transmission characteristics of acoustic filters under static (i.e. no flow) conditions. These characteristics are obtained by the combination of linear plane wave acoustic theory with a sequential experimental procedure. The experimental data necessary for the calculation of the reflection characteristics were obtained from measurements made on the inlet side of the filter with a standing wave tube apparatus. In order to calculate the transmission characteristics of the filter, the standing wave measurements were augmented with measurements taken on both the inlet and outlet side of the filter. This was accomplished …

An Aggregate Quality Investigation Of The Meramec River Gravels, Kadri Ercin Kasapoglu

Masters Theses

"This thesis represents a study which was made to evaluate and interpret the downstream variations in the quality of the Meramec River gravels as coarse aggregate for concrete. Since gravel deposits constitute a valuable resource for a region, it is desirable that extent and quality variations of these deposits are known. It was hoped that an evaluation of certain properties of the Meramec River gravels would assist in determining the value of the Meramec River as undeveloped aggregate source by indicating the relative quality of the gravels from alternate sites of the river. For the purpose of this investigation, representative …

Plastic Analysis Of Beam - Columns, Ning-Cheng Tsao

Masters Theses

"The results of an analytical study of the inelastic deformation of a wide-flange steel beam-column are presented. Emphasis has been placed on the influence of axial thrust on the pinned-end beam-column subjected to equal end moments with opposite direction. For this type of beam-column behavior, the relationship between the applied moment, axial load, and resultant curvature for the region in the plastic range has been studied in this investigation"--Abstract, page ii.

The Design Of A Direct Current Generator Field Controller, Melvyn Elwin Downs

Masters Theses

"A controller was built utilizing transistors and silicon controlled rectifiers to allow torque control of the General Electric dynamometer, type TLC-50. The current gain of the controller was approximately 10⁶ such that the field current could be controlled by an input current of zero to approximately two microaaperes. The transfer function for the controller-dynamometer system was experimentally determined. The results indicate that the gain of the open loop torque control system is constant for frequencies up to 1.1 radians per second. Satisfactory values of gain for proportional and proportional plus integral control, were experimentally determined by operating the closed loop …

Scraped-Surface Heat Exchange, Kyung Jun Park

Masters Theses

"An experimental study was made to test a theory developed for scraped-surface heat exchange. The apparatus was a cylindrical vessel equipped with two blades and baffles, cooled in an ice bath. The experiments showed the approach of dimensionless temperature deviated greatly from the theoretical prediction. It was found that part of this effect was the result of a change in temperature of the scraped wall, which could be accounted for by using the overall heat transfer coefficient between the cooling medium and the apparatus. Measurements on water showed the cooling rate to be much faster than the theory would predict. …

Signal Distortion In A Regenerative Frequency Divider, Carl Ray Ryan

Doctoral Dissertations

"A regenerative frequency divider can be constructed with one integrated circuit and a single-pole tuned circuit. The divider can be used as a means for reducing the modulation index of either deterministic or random signals. This reduction in modulation index can simplify many signal processing schemes. This technique can be used up to S-band frequencies. The mathematical model of the regenerative frequency divider corresponds very closely to that of a first order Phase Locked Loop (PLL). The loop gain is determined in part by the nonlinear element used in the feedback loop. The loop gain is also proportional to the …

X-Ray Determination Of Lattice Parameters And Thermal Expansion Coefficients Of Aluminum, Silver And Molybdenum At Cryogenic Temperatures, Claude Lowell Woodard

Doctoral Dissertations

"A multiple exposure back reflection diffraction camera was designed to mount on the vacuum jacket of a pressurized helium gas "Cryomite". With this design it is possible to obtain six diffraction exposures on a single film at any temperature in the range of 180 to 25°K. temperatures within this range are reached in short intervals and exposure periods are less than 30 minutes in a 2.875 inch (73.03 mm) diameter camera. Some of the advantages of this design are; direct measurements, multiple exposures on a single film, short exposures, direct compensation of film length changes due to evacuation or processing …

An Optimization Approach To Well Spacing For Gas Storage Reservoirs, Jagannath Rao Ghole

Doctoral Dissertations

"A finite approximation to the conventional diffusivity equation describing compressible fluid flow through porous media has been developed with a view to apply it to the problems of optimum well spacing. An equilateral grid system has been employed to enable uniform well spacing for any number of wells. A numerical model has been developed on an IBM 360 - Model 50 computer, which simulates the pressure and saturation transience in the reservoir due to production impulses. This model has been used to maximize with respect to number of wells, the minimum well bore pressure reached throughout the specified withdrawal schedule. …

A Theoretical Study On The Interpretation Of Resistivity Sounding Data Measured By The Wenner Electrode System, Siew Hung Chan

Doctoral Dissertations

"This thesis deals with a theoretical study on the interpretation of resistivity sounding data measured by the Wenner electrode system. The objectives of this investigation are twofold: (i) to derive from the apparent resistivity data some suitable functions from which the resistivity and thickness of each member of the sequence of layers composing the earth may be determined, and (ii) to devise suitable methods for analyzing the resulting functions. In this investigation it is shown that the solution of the boundary value problem associated with an n-layered earth model leads to an integral equation for the Wenner electrode system. This …

The Irish Plumbing And Heating Engineer, January 1969 (Complete Issue)

Building Services Engineering

No abstract provided.

A Method For Determining Transient Stability In Power Systems, Charles A. Gross

Doctoral Dissertations

"Given a three phase ac power system consisting of synchronous alternators interconnected by transmission lines and other items of electrical transmission equipment, a method is presented which determines the stability of the system when subjected to a three phase symmetrical fault, and to the subsequent clearing of the fault. It is inherent in the method that an estimation of system stability, assuming an instantaneous clearing of the fault, is available. The critical clearing time is therefore determined. The effect of a speed control loop on the system's largest machine is investigated. The method is applied to two, three, four, and …