Engineering Commons^™

Comprehensive Calculations Of The Parameters Describing Proton Energy Loss In Matter, Joseph F. Janni

Nuclear Engineering ETDs

Extensive calculations have been made of the mean energy loss, pathlength, range, multiple scattering, and pathlength straggling of protons in many materials. Emphasis has been placed on obtaining accurate results, especially for heavy materials and protons of very low energy. Values of the energy loss between .01 and 1.0 Mev were obtained by smoothing and interpolating experimental information. Above 1.0 Mev, the Bethe equation with all the necessary shell corrections has been used. Values of the adjusted ionization potential have been determined by least squares fitting the Bethe equation to all available energy loss data. The polarization effect has been …

Theoretical And Experimental Study Of Explosive Closures Of 6061-0 Aluminum Pipes, Lyle E. Edwards

Mechanical Engineering ETDs

This thesis examines the use of explosives to collapse metal pipes from an applications point-of-view. A particular system is studied, both theoretically and experimentally, in order to facilitate the future design of such closures with the least possible physical testing. The calculations are based on a rigid-perfectly plastic model of the observed deformations of the tubes, and on various assumed am derived properties of the metal and sheet explosives under the dynamic conditions of closure. A computer program has been devised which simulates the actual motion of a pipe during collapse. Experimental work involved actual test firing of aluminum cylinders …

Techniques For Active 3he Activation Analysis For Carbon And Oxygen, William Mort Sanders

Nuclear Engineering ETDs

The surface and body concentrations of carbon and oxygen have been measured in various materials using ³He activation. Channeling techniques have been used to differentiate between interstitial and substitutional location of these impurities.

Thin target excitation functions were determined for (³He,p) reactions with carbon and oxygen over a ³He energy range from 2.5 to 9.0 MeV. These data were used to calculate the activation curves for various combinations of incident particle energy, impurity distributions, and material.

Information on several computer codes used during this study is presented.

Dynamic And Thermal Studies Of Micron Size Metallic Particles In A Nonequilibrium Low Pressure Argon Plasma Jet, Barry R. Maxwell

Mechanical Engineering ETDs

Dynamic And Thermal Studies Of Micron Size Metallic Particles In A Nonequilibrium Low Pressure Argon Plasma Jet

An Analysis Of The Behavior Of A Non-Newtonian Fluid In A Flow Reactor, Asahiro Ahagon

Chemical and Biological Engineering ETDs

Velocity, temperature and concentration profiles were derived for non-Newtonian laminar flow of a reacting species in a tubular reactor. The equation of motion based on a temperature dependent power-law fluid model and the energy equation with internal heat generation caused by a first order chemical reaction were coupled and solved simultaneously using numerical methods to yield the profiles. The assumptions made in this study were: constant physical properties of the fluid (density, thermal conductivity and heat capacity). fully developed flow, wall temperature and negligible diffusion. Compartmentalized calculations resulted in velocity, temperature and reactant concentration profiles for both the axial and …

The Use Of Graphical Techniques In Construction Management, Varne M. Kimmick

Civil Engineering ETDs

The relation and practical uses of graphics in construction management is a study area in which little work, with the exception of the critical path method, has been done. As the subject was begun, it was discovered there was little specific written material on the graphs themselves; therefore, a considerable portion of the thesis was devoted to basic graphics in order to make the discussion relative to construction more meaningful. Chapters I through VII cover the subject of basic graphics. The basic graphics portion was considered essential to the study in order to allow practical use of the work by …

Strain Measurements At Extremely High Temperatures Using Moiré Fringe Techniques., Joseph W. Neudecker Jr.

Mechanical Engineering ETDs

A new procedure is described for using the moiré-fringe technique to measure strains in structural materials at temperatures exceeding 1300 °C. The principal factor found to be necessary for successful viewing of moiré patterns at extremely high temperatures is the use of reflected laser light for viewing the strained grid on the material. This factor is extensively discussed and experiments are described in which strain measurements were successfully made on graphite specimens at elevated temperatures. It is concluded that the techniques described constitute a more feasible method of measuring strains at higher temperatures than is possible by any other known …

A Statistical Theory Of Avalanche Breakdown In Silicon, Terence Vincent Sewards

Electrical and Computer Engineering ETDs

A statistical theory of avalanche breakdown in silicon is presented, based on the conventional Boltzmann transport equation. The scattering mechanisms considered are impact ionization (electron-hole pair production), phonon emission and absorption, thermal generation and recombination. The resultant critical field is found to depend on the recombination statistics, which were ignored in previous theories of avalanche breakdown. The theoretical temperature dependence is compared with the temperature dependence of the breakdown voltages of three conunercial diodes.

The Development And Use Of Scattering Parameters For Semiconductor Junction Devices, Lee Dennis Philipp

Electrical and Computer Engineering ETDs

Scattering parameters are developed for diodes and tran­sistors. The parameters are developed through a modification of the wave equation from quantum mechanics. The effects of pulsed X-ray radiation on these devices is then calculated with the use of these parameters.

Various methods of analyzing semiconductor junction de­vices are discussed. These methods include diffusion theory, invariant imbedding and quantum mechanics. The background in these areas necessary for a discussion of semiconductor models is outlined.

Models resulting from the three basic approaches are presented. These include the Ebers-Moll Model, the Charge Control Model, the Linville Model, the Gore Model, the MLB (McKelvey, …

An Experimental Study On Heat Transfer Coefficient For Carbon Laden Gas, Jacob Chi-Kwong Huang

Chemical and Biological Engineering ETDs

Abstract

A complete carbon black pilot plant was employed in this study. Carbon laden gas was produced in a fur­nace and introduced into the outer pipe of a heat ex­changer. Air, at the same time, was introduced into

the inner pipe of the heat exchanger cocurrently with the carbon laden gas. Thus, heat, with temperature dif­ference as driving force, would transfer from the car­bon laden gas to the air stream. The temperatures along the two streams were measured by iron-constantan ther­mal couples and recorded by a multi-reading temperature

recorder. Air supply and fuel (C3H8) supply were intro­duced into the furnace …

Preparation Of Metallic Oxide Aerosols By Vaporization And Degradation Of Organic Compounds, Tom B. Larsen

Chemical and Biological Engineering ETDs

Simple, dependable methods for the generation of aerosols are necessary to many forms of research. Specifically inhal­ation research has a requirement for sub-micron sized insoluble particles.

Two different methods for the production of oxide aerosols from vaporizable compounds were tried. The first method, a mod­ification of the Rapaport-Weinstock generator (R3), consisted of nebulization of a solution into a droplet mist. Next the drop­lets were vaporized, and condensation nuclei formed from the nonvaporizable impurities in the solution. The vapor was allowed to condense on the nuclei in a relatively large chamber, then the resulting liquid droplet aerosol was dried and converted …