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Full-Text Articles in Physics

The Effect Of Hot Dense Hydrogen And Argon In A Ballistic Compressor On The Structure And Composition Of Pure Iron, David Samuel Silver Mar 1990

The Effect Of Hot Dense Hydrogen And Argon In A Ballistic Compressor On The Structure And Composition Of Pure Iron, David Samuel Silver

Dissertations and Theses

An experimental study of pure iron foil exposed to a hot, dense hydrogen and argon gas mixture in a ballistic compressor yielded evidence of structural and compositional changes of the metal due to the presence of the hydrogen gas. Three iron foils have been compared, one of unexposed pure iron, another of pure iron exposed to a mixture of hydrogen and argon gas, and the third of pure iron exposed to argon alone. Exposure to these high temperature, high pressure gases took place in a ballistic compressor.

Line formations were found on the surface of the iron foil exposed to …


A Theoretical And Experimental Study Of The Three-Ring Electrostatic Electron Lens, Thomas Anthony Sommer Jan 1990

A Theoretical And Experimental Study Of The Three-Ring Electrostatic Electron Lens, Thomas Anthony Sommer

Dissertations and Theses

A theoretical and experimental study of the three-ring electrostatic lens is presented. The lens consists of three isolated ring-shaped conductors, equally spaced along a common axis of symmetry. When appropriate potentials are applied to the conductors an electric field is produced near the axis which is capable of focusing a collimated beam of electrons. In the theoretical study the charge density method is used to find a closed-form solution for the field. This method approximates the field by replacing each ring with an infinitely thin hoop of uniform charge. The radial and axial equations of motion are then solved numerically, …


Optimization And Thermodynamic Performance Measures Of A Class Of Finite Time Thermodynamic Cycles, Joseph D. Walters Jan 1990

Optimization And Thermodynamic Performance Measures Of A Class Of Finite Time Thermodynamic Cycles, Joseph D. Walters

Dissertations and Theses

Modifications to the quasistatic Carnot cycle are developed in order to formulate improved theoretical bounds on the thermal efficiency of certain refrigeration cycles that produce finite cooling power. The modified refrigeration cycle is based on the idealized endoreversible finite time cycle. Two of the four cycle branches are reversible adiabats, and the other two are the high and low temperature branches along which finite heat fluxes couple the refrigeration cycle with external heat reservoirs.

This finite time model has been used to obtain the following results: First, the performance of a finite time Carnot refrigeration cycle (FTCRC) is examined. In …