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Cavity Effect In A Pressure Bar, Kenneth B. Simmons

Mechanical Engineering ETDs

The investigation deals with certain aspects of wave propagation in a rod containing a penny-shaped cavity, particularly fracture related to the presence of the cavity. When a rod containing a cavity is subjected to a compressive stress pulse, part of the pulse is transmitted past the cavity and part is reflected. When the end of the rod is free, the cavity is subjected to a reflected tensile pulse which, if strong enough, can cause fracture. The existence of the cavity tends to weaken the rod since there is a reduction in the cross-sectional area and a stress concentration effect. Epoxy …

The Effects Of Repeated Loading On The Modulus Of Elasticity Of Concrete, Fidel T. Smith

Civil Engineering ETDs

Under present design methods, the modulus of elasticity is designated only with respect to the ultimate strength and the unit weight of concrete and is assumed constant throughout the life of the structure. The only provision made for change in the modulus of elasticity due to age, moisture content, type of loading or fatigue is to assume the weakest condition of the concrete. On elastic analysis the stress-strain relationship is assumed to be linear and the concrete is assumed to carry no tensile stress. In ultimate design procedures the concept of straight line distribution of stress is dropped and a …

Transient Response Of Linear Damped Lumped Spring-Mass Systems By Experimentally Derived Transfer Functions, Ralph W. Kelley

Electrical and Computer Engineering ETDs

In the field of mechanical shock testing, there are many instances where the responsive motions of linear undamped and lightly damped lumped spring-mass systems must be determined. If a model representing the system to be tested is available, it is possible to determine the responsive motion by several different approaches. Most of these methods require solving the differential equation of motion in some manner. Among the more common methods of solving the differential equation are the classical solution, the use of Laplace transforms, and various graphical techniques. All of these methods, however, require that a model of the system under …

Directional Effects Of Transient Radiation On Semiconductor Devices, Arthur C. Golubiewski

Electrical and Computer Engineering ETDs

The purpose of this study is to determine the directional effects of transient gamma radiation on electronic components. An analytic expression will be developed for radiation effect as a function of angle, and experiments will be described which verify the mathematical analysis.

The Electrical Conductivity Of Some Cryogenic Fluids, Walter L. Willis

Electrical and Computer Engineering ETDs

Cryogens (liquefied gases with low boiling points) are, in general, excellent insulators. Prior to this investigation, no measurements of conductivity in cryogens had been successful. An upper limit of conductivity in the range 10^-15 to 10^-17 mho/cm had been established for some cryogens. Data from the organic chemicals and petrol m industries indicated that fluids with conductivities in the 10^-11 to 10^-15 mho/cm range could present electrostatic potential hazards, particularly in situations of large volume storage and high flow rates. The advent of large capacity dewars and associated high flow rates of cryogens in the aerospace …

The Irish Plumbing And Heating Engineer, March 1965 (Complete Issue)

Building Services Engineering

No abstract provided.

A Mechanical Thevenin Equivalent Circuit Of A Separately Excited D.C. Motor, Hershel R. Lung

Electrical and Computer Engineering ETDs

This problem is concerned with the transient analysis of a DC machine with constant field excitation. By using the generalized circuit concept and Thevenin's Theorem applied to this concept, the transient behavior of this type of machine can be found from an analysis of a lumped circuit model of the machine. The lumped circuit model is a three port device and as such, the terminal equations describing the relationship between the difference and flow signals at the various ports are nonlinear. The nonlinear terms due to the products of signals in the terminal equations can be eliminated by requiring that …

Small Prolate Spheroidal Antenna In A Dissipative Medium., William Troy Cowan

Electrical and Computer Engineering ETDs

A perfectly conducting prolate spheroidal antenna immersed in a conducting medium is analyzed. It is assumed that the dimensions of the spheroid are small compared to a skin depth in the medium. A gain factor for the antenna as a receiver is computed as a function of the spheroid's axis ratio. The prolate spheroid is assumed to be excited by a circular filament of magnetic current located in the plane of the spheroid's minor axes to approximate excitation by a magnetic toroid. Expressions for the antenna's input admittance and effective length are derived. Some experimental results verifying the derivation of …

Milking Machine Efficiency And Shed Husbandry Practices, G R. Olney

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

MILKING machine efficiency on dairy farms in the Bridgetown, Greenbushes, Balingup, Boyup Brook and Nannup areas was the subject of a recent testing survey.

During the survey 106 machines were tested and the results assessed statistically to gauge the general level of machine efficiency in these districts.

Lot Feeding Of Beef Cattle. 3. Facilities Required For A Feed Lot, W J O Wilkie

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

MANY THINGS must be considered in planning a feed lot.

The site must be well chosen, fencing, gates and yards must be adequate for the cattle carried and feeding and watering facilities should be of a high standard.

Other things to consider are the provision of shelter and shade for the cattle and buildings for feed storage and other purposes.

Design Of A Photoelectric Transient Torque And Speed Meter, Raojibhai A. Patel

Masters Theses

"There are many situations in which it is desirable to know the speed of the shaft and the torque it is transmitting, when it is equally undesirable to make any mechanical connection to the shaft. This thesis describes the development and design of a device for measuring the torque and speed by photo-electric means. The basic principle is that a light beam parallel to the shaft may be used to pick up the desired information without adding friction to the system. The deflection of a torque tube inserted in the shaft opens or closes a set of apertures arranged in …

A Study Of The Structural Rearrangements Accompanying Room Temperature Recovery Of High Purity Aluminum, Carlos Manuel Lago

Masters Theses

"X-ray methods (Laue back reflection and transmission) and etch pit studies were used in order to follow structural changes in the deformed metallic lattice during room temperature recovery. The accumulative evidence indicates that the deformed lattice undergoes subboundary movements and regrouping of fragments within a few days after stressing. On the basis of a superficial investigation, it was found that fast neutron bombardment increases the rate of room temperature recovery. Through the use of a new etchant, a finer substructure was revealed within the Lacombe subgrain. Glide strain values were determined for the series investigated, and a new approach was …

Determination Of The Temperature Distribution Of The Ionized Portion Of The Jet From A Vortex Stabilized Plasma Generator Operating On Argon, G. Douglas Schellman

Masters Theses

"The interim thesis deals with the determination of the temperature distribution of a plasma jet operating on argon. It is the purpose of this thesis to present in detail the experimental process used and make a correlation of the experimental and theoretical results.

A copper enclosure was placed around the protruding flame, and the embedded thermocouple readings were taken and recorded. A stagnation temperature probe was inserted in the enclosure and moved both axially and transversely toward the flame taking readings at each pre-chosen interval. The exit temperature of the jet was obtained from a total energy balance.

From the …

Turbulence In Journal Bearings, Kashyap R. Mehta

Masters Theses

"In this investigation, an experimental study was performed on a journal bearing under laminar and turbulent flow conditions. Using relationships for friction factor developed previously by other investigators a comparison was made with results of this present investigation. Since the flow changes from laminar to turbulent with a change in speed of rotation, curves for friction factor as a function of speed were plotted. Various attempts to make the recording and measuring systems more sensitive were also made and are discussed in this thesis"--Abstract, page ii.

Heat Transfer Coefficients Across Bonds And Contacts, Eugene Charles Fadler

Masters Theses

"The purpose of this investigation was to experimentally determine heat transfer coefficients across interfaces, including the effects of the thermal conductivity of the adherends, the hardness of the adherends, the bond thickness, and the type of adhesive.

Aluminum alloy, steel, copper, and extruded nylon rods were used as adherends; all 1.875 inches diameter and 8 inches long. Each was cut radially at its midpoint and faced off to the desired surface finish. Bare interface tests were conducted before the adherends were bonded together. The adhesives used were high grade silica refractory cement, two-part epoxy resin adhesive, and thermosetting synthetic rubber-phenolic …

Kinetics Of Base-Catalysed Reactions, Kunjvihari Ramanlal Mehta

Masters Theses

"The work of Wulfman on the mechanism of the Michael reactions suggests that the normal Michael reaction is second order kinetically, with the rate being proportional to the concentration of the acceptor and the active form of the addendum. A detailed reaction mechanism of normal Michael reaction was not proposed due to insufficient data which resulted from analytical difficulties. This investigation involves the study of the kinetics of normal Michael reaction from the stand point of base strength, solvent concentration and acidity of the reactants, solvent and products"--Experimental. A. Purpose of Investigation, page 17.

A Photoelastic Study Of The Effect Of Certain Geometric Variables On The Plane Stress Distribution In An Electrical Insulator Body, Richard L. Pendleton

Masters Theses

"Photoelastic models were used to indicate stress patterns in various geometrically designed shapes. Each model represented a two-dimensional cross-section of the interior portion of an axially symmetrical porcelain electrical insulator. Five different loading pins were combined with three loading heads to produce eleven models. The maximum stress in each model was determined using a photoelastic method of stress analysis. An attempt was made to select the best structural design to be used in an electrical insulator. The test results indicate that the most desirable stress distribution is obtained using a single step loading pin and that the loading head angle …

Internal Friction Of Mixed-Alkali Silicate Glasses, James E. Shelby

Doctoral Dissertations

"The mixed alkali effect in silicate glasses was examined from internal friction measurements made over the temperature range from -190 to 500⁰C and at a frequency of 0.4 Hz. Supplemental measurements of the activation energy for the different internal friction peaks, dynamic shear modulus, density, and index of refraction were also made. All measurements were confined to silicate glasses containing mixtures of Li-Na, Li-K, Li-Rb, Li-Cs, Na-K, Na-Rb, Na-Cs, and K-Rb. Rötger's interpretation of the internal friction of mixed-alkali silicate glasses is shown to be incorrect. A previously unreported internal friction peak was observed whenever two different alkali oxides were …

Linvill's Model As Applied To P-N Junction Photo-Diodes, Rudy Michael Chittenden

Masters Theses

"The problem undertaken in this study is to present a performance evaluation of Linvill's model as it pertains to the p-n junction photo-diode. The evaluation is performed by comparing the distributed mathematical solutions, the solution obtained using Linvill's lumped model, and the experimental measurement of the transient voltage rise across a photo-diode due to a unit-step pulse of light incident on the junction. Despite the absence of a suitable light source for use in the experimental measurement, it is concluded that Linvill's model provides an excellent means to determine the risetime of a photo-diode. This is provided that the photo-diode …

The Dielectric Properties Of A Synthetic Fluor-Mica Formed By Glass-Ceramic Fabrication Techniques, Ray Fred Schumacher

Masters Theses

"A tetrasilicic fluor-mica, K₂Mg₅Si₈O₂₀F₄, was synthesized, utilizing glass forming techniques and subsequent heat treating of the mica glass. Discs, approximately two inches in diameter, were formed and heat-treated at selected temperatures between 700⁰C. and 1150⁰C. for various time periods. Density change, weight loss, shrinkage, and dielectric properties were measured to determine the characteristics of this material"--Abstract, page ii.

Analog Simulation Of A Synchronous Machine, J. Derald Morgan

Masters Theses

"The problem presented here is a study by an analog computer simulation of a synchronous machine under balanced three phase, short-circuit conditions. The purpose is to obtain a solution that is more accurate than one obtained by approximate methods using transient and subtransient reactances as is often done. This simulation is accomplished by using an idealized synchronous machine. The equations relating voltage and currents in the machine, as well as speed and torque, are presented for simulation. The equations for the machine include the saliency of one member, as well as the effect of speed and the damper windings. A …

A Feedback Compensator Design For Linear Control Systems, Thsai-Ten Lin

Masters Theses

"The compensation process in control system engineering is indispensable. The addition of a compensator to a fixed plant can often make the system meet certain specifications easily. In this study an attempt was made to use a general purpose digital computer to design a feedback compensator. The method developed is first to determine the minimum gain of the amplifier and the number of compensator poles and zeros based on the given specifications. then free hand root-loci are plotted, with several combinations of possible compensation variables. These data are used as the open-loop transfer function from which the poles and zeros …

The Effect Of Submerged Jets On The Hydraulic Jump, Harvey E. Jobson

Masters Theses

"Tests were performed in order to determine the effects of forcing submerged jets of water into the base of a hydraulic jump. The specific energy of the water leaving the hydraulic jump, the length and the wave formation properties of the jump which had been modified by the introduction of submerged jets were determined and compared with the same characteristics of a normal hydraulic jump and a hydraulic jump which had been modified by the use of baffle piers.

Test results indicate: (a) the quantity of water flowing through the submerged jets is a primary factor in determining the specific …

Transient Temperature Distribution In A Finite Cylinder And An Infinite Cylinder Subjected To Some Boundary Conditions, Harng-Sen Huang

Masters Theses

"This thesis is concerned with the theoretical heat transfer analysis of solid cylinders. The first problem considered is the transient temperature distribution in a finite cylinder. This cylinder has a uniform initial temperature and a uniform constant surrounding temperature. This case is solved by the separation of variables. Combining the charts for the infinite cylinder and the charts for the infinite plate one can determine the solution to this case easily. If a uniform constant surface temperature is prescribed instead of a surrounding temperature, the solution can be obtained from the previous one by charging the Nusselt number to infinity. …

The Development And Evaluation Of An Experimental Technique To Determine Stress Distribution In Uniformly Loaded Flat Plates, James William Walker

Masters Theses

"This thesis reports and evaluates an experimental technique that was developed to determine and monitor the stresses in a simply supported, uniformly loaded circular plate. Deflections are less than half the thickness of the plate. The application of the developed technique to plates whose integrity has been compromised with holes in various locations is discussed.

Resistance strain gages were used to determine experimentally the stresses in a simply supported, uniformly loaded circular plate with and without a concentric hole. The accuracy of the experimental results was established to be within approximately six percent of theoretical.

Proper application of the experimental …

Cylinder-Head Surface Temperature And Maximum Pressure In A Diesel Engine, Jayant M. Patel

Masters Theses

"This report presents the result of an experimental investigation on the effect of 1) fuel consumption in a diesel engine on the mean cylinder-head surface temperature 2) engine speed and load on the maximum cylinder pressure.

A fast-response thermocouple was fixed in the cylinder head and temperatures were measured for various load and speed conditions. An attempt was made to record a transient surface temperature versus crank-angle diagram. Some doubt as to the reliability of this recording may arise because of the very small amount of time lag in the thermocouple action. This is immaterial to the subject of this …

Investigation Of The Use Of Optics In The Analysis Of Structures, Jimmy D. Hahs

Masters Theses

"This study was made to determine the feasibility of the use of optics in the analysis of structures. Since the curvature of a beam due to a loading condition is a function of the moment, a measure of this curvature is a measurement of the moment.

This study used the relationship between object size and image size formed by a concave or convex reflective surface to determine the radius of curvature and the moment at the point.

Overhanging simply supported beams of plexiglass with concentrated loads at various positions were used to demonstrate the developed optical theory. Optical measurements were …

The Construction Of A Single Crystal Neutron Diffraction Unit And Measurement Of Effective Neutron Temperature, Larry Dean Thompson

Masters Theses

"The continued expansion of the nuclear reactor facility and the nuclear engineering program makes it desirable that a neutron spectrometer be available at the reactor facility. This unit would be available for use in graduate and undergraduate laboratories and for graduate research.

A single crystal, white radiation spectrometer including collimator, automatic controls, and shielding was designed and constructed.

The performance of the unit was checked using LiF and Cu crystals. A rocking crystal curve and a θ - 2θ curve was obtained with each crystal. The effective neutron temperature was then determined from the LiF crystal θ - 2θ curve"--Abstract, …

Comparison Of Measured And Calculated Stiffnesses For Lightweight Normal Concrete Beams, Raman Patel

Masters Theses

"This study is a presentation of the findings involving experimental measurements of stiffness (EI) for different percentages of reinforcement steel in normal and lightweight concrete beams. The experimental values of stiffness are compared with calculated values obtained by applying the standard reinforced concrete theory. The measured values of stiffness obtained by the rotation method are compared with those obtained by the deflection method. Of the thirty beams that were tested, fifteen were tested for normal concrete and the remaining fifteen for lightweight concrete. Each of these beams were tested at different ages, ranging from seven to twenty-eight days.

The test …

The Elastic And Anelastic Constants Of A Synthetic Fluor-Mica Formed By Glass-Ceramic Fabrication Techniques, John H. Ainsworth

Masters Theses

"A tetrasilicic fluor mica, K₂Mg₅Si₈O₂₀F₄, was synthesized using glass forming techniques. Density changes, weight losses, and shrinkage, as well as elastic and anelastic properties, were measured on bars heat-treated at selected temperatures between 500°C and 1150°C to determine the characteristics of this material. Phase changes were followed by determining thermal expansion, logarithmic decrement, and modulus of elasticity from room temperature to 800°C.

It was found that the elastic and anelastic constants decreased gradually with heat treatments from 600°C to 1000°C. This indicated progressively increased structural ordering. Heat treatments above 1000°C …