Engineering Commons^™

Measurement Of Fluid Velocities In A Simulated Heat Pipe, Lewis Collin Moore

Mechanical Engineering ETDs

Velocity components of numerous geometries may be measured with the laser Doppler technique. Combinations of system parameters were investigated that were useful for constructing a two-dimensional velocimeter for a tube with porous walls. A method was developed which combined a local oscillator with a crossed-incident beam using backscatter at very small angles from the longitudinal axis. Seeding requirements, electronics signal processing, permeability measurements, and measurement point constraints were investigated. Preliminary fluid velocity results were obtained, and recommendations are made for further improvements to overcome the difficulties encountered in the current investigation.

Large Deflection Analysis Of Laterally Restrained Reinforced Concrete Slabs, Satwant Singh Rihal

Civil Engineering ETDs

This dissertation is an attempt to analytically predict the large deflection behavior of orthogonally reinforced concrete slabs. The problem considered is that of a laterally restrained, simply supported square slab under uniform loading. The range of loading considered is from zero load to the load at which yielding first commences in the steel reinforcement.

This problem is first formulated using the classical large deflection theory of homogeneous plates. This formulation is based on a constant overall stiffness for the entire slab.

A modified large deflection theory is next developed for reinforced concrete slabs. In this theory concrete on the tension …

A High Voltage Regenerative Pulse Modulator, James D. Doss

Electrical and Computer Engineering ETDs

This paper describes the design of a High Voltage Pulse Modulator that employs positive feedback to generate output pulses of variable width. The modulator is intended for use as a switching device to drive the modulating anode of a five-cavity klystron. The klystron develops more than one million watts of peak power at a frequency of 805 MHz, with duty factors up to 12%. The modulating anode voltage drive requirement is approximately 80 kV with the current drain being of the order of 0.01 ampere. The total modulator current output will be approximately one ampere with most of the current …

Stability Analysis Of Nuclear Reactor Feedback System, Ashok K. R. Bizzul

Electrical and Computer Engineering ETDs

A nuclear reactor feedback control system is analyzed for stability conditions in frequency domain by two methods. The nuclear reactor is modeled by a single delayed neutron group model, and the methods of analysis are Popov's analysis and describing function analysis. The feedback system with linearized nuclear reactor model is analyzed by Popov's method. A more exact non-linear reactor model is used in the feedback control system for describing function method of anal­ysis. It is found by both methods that the system is absolutely stable. But describing function analysis gives greater insight to the study of the relative stability of …

A Numerical Study Of The Coanda Effect., Soloman P. Chavez

Mechanical Engineering ETDs

A numerical solution for the flow in a two-dimensional bistable fluid amplifier is obtained. A minimum Reynolds number is found below which attachment will not occur. The study shows the quality of attachment and attachment point varying with Reynolds number.

Military Environics - Water And Waste, James Anthony Mahoney

Civil Engineering ETDs

This thesis summarizes the activities of the United States Military Services effort, in the areas of water supply, waste water treatment, and solid waste disposal for personnel of the Armed Forces and their dependents. This thesis surveys the state-of-the-art of the present sanitary facilities in the United States and abroad as associated with the military environment. Chapter I compares the responsibilities of the military installation engineer to that of a municipal public works director. Discussed are the service laboratories and their locations. Chapter II includes supply, treatment, design, distribution and storage of water. It is concluded with a reference section …

Vertical Force Measurement For The Chaparral Rocket Sled, John C. Gustafson

Mechanical Engineering ETDs

A study of the feasibility of instrumenting existing structures with strain sensing elements to measure a specific component of force transmitted by the structure in use has been conducted. A specific structure, the front slipper assembly of the Chaparral rocket sled, was used in this study. The developmental phase of this work was conducted through the use of a model study. The model studies were made to determine appropriate stress raisers and locate strain gages so the desired force component could be measured. The actual structure was modified in accordance with the results of the model tests. Calibration tests and …

Reliability Aspects Of Micropower Majority-Charge Logic, James T. Henderson

Electrical and Computer Engineering ETDs

This thesis is a study of the reliability aspects of micropower majority-charge techniques as applied to fundamental-mode clocked-se­quential circuit design. A· sample sequential circuit is used as the basis for the extension of previously developed circuitry. This previously developed circuitry is applied to the sample sequential circuit in the form of Micropower Majority-Charge Flip-Flops. These flip-flops are very immune to transient noise and offer reduced power consumption over standard integrated circuit flip-flops by pulsed power application. The use of AND gates and OR gates with amplifiers and NAND gates or NOR gates for memory elements is reported. It is shown …

Improved Numerical Techniques For Three Dimensional Transient Conduction Coupled With Surface Radiation And Variable Emissivities, Jimmie H. Smith

Mechanical Engineering ETDs

The problem of transient conduction combined with surface radiation and variable emissivities is solved numerically. The existing, but little used, multidimensional Douglas-Peaceman-Rachford alternating-direction-implicit (ADI) technique for finite differencing is chosen as the best available. It is modified and applied to the three-dimensional transient heat equation with source term. Techniques for blocking conduction in excluded directions are demonstrated. Quasi-linearization is used to combine the radiant enclosure calculations with the transient conduction calculations. That is, on an alternating basis, a time step in conduction is followed by a radiant enclosure solution. The radiant enclosure problem is solved in a novel manner, combining …

An Experimental Study Of Radiation Effects On Metal-Insulator-Semiconductor Structures., Robert James Kopp

Electrical and Computer Engineering ETDs

It is heuristically desirable to automatically display the capacitance-versus-voltage {C-V) and conductance-versus­voltage (G-V) curves (including hysteresis) of metal-insula­tor-semiconductor capacitors at times subsequent to irradiation. Ultimately, these data will be used to assess the effects of ionizing radiation on the character of the surface states within the device. The purpose of this thesis is to describe in some detail the operation of circuitry that has been designed and fabricated at the University of New Mexico, and that is currently in use here in making automated measurements of this type. Also, the data are placed in a descriptive context involving a compendium …

A Computer Multistage Optimization Method On Ethane Decomposition, Jonathan K. Ma

Chemical and Biological Engineering ETDs

The prediction of conversions and product distributions under various conditions is of prime interest in the process design of an optimum reactor. This is a very difficult task when a complex reaction is under consideration; since reactions take place simultaneously the relationship of the individual reaction and the over-all product distribution and their correlation with the control variables are hard to define. This study is an application of the free radical mechanism of the thermal decomposition of ethane to calculate the product distribution. Since this is an endothermic reaction, the temperature profile is the control variable. The relationship between the …

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 …

Reflection And Transmission Of Dipole Radiation In Presence Of An Extended Boundary, Rough And Smooth, Byong Ki Park

Electrical and Computer Engineering ETDs

Several different forms of integral solutions exist to the problem of dipole radiation in presence of a half space with plane boundary, all of which can be easily shown to agree with one another by transformation. For the evaluation of these integrals, a number of assumptions are usually made on some parameters in the expressions such as the medium property, the wavelength and so on. Unfortunately, however, even with these simplifying (but meaningful) assump­tions, practically useful results for the dipole radiation problem are still lacking. Also it appears that there is no theory of dipole radiation when the plane boundary …

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 …

Shock Shields, Asbjorn Kvammen Jr.

Civil Engineering ETDs

A series of tests was conducted to obtain information concerning the effectiveness of a shock shield of reinforced concrete between ground surf ace and a buried structure as a means of reducing the shock transmitted to the structure due to airblast loading. Two shock shields were used. The diameter of both shields was 20 inches and the thicknesses were 6 inches and 2 feet. The structure was 20 inches in diameter with a thickness of 5 feet. Tests were performed in a 2- by 40-foot shock tube without shock shield and structure, with structure only, and with different thicknesses of …