Physics Commons^™

The Thermal Conductivity Of Sodium Chloride At Elevated Temperatures, Howard Martin Brown

Masters Theses

"The thermal conductivity of solids has been attributed to a combined effect of the quantized vibration of the lattice points, called phonons, and the flow of valence electrons. In nonconductors the thermal conductivity is due almost entirely to phonons, as was shown by Debye, whereas in metals the conductivity is due mostly to the flow of valence electrons. After Debye, Peierls calculated the lattice conductivity at elevated temperatures using quantum mechanics and demonstrated that it is proportional to 1/T. There are not enough data available to substantiate any theory but what data there are seem to indicate a mixed conductivity …

The Velocity Of Ultrasonics In Liquids, Mack A. Breazeale

Masters Theses

"In acoustics the term ultrasonics is used to refer to those frequencies which are above the range of human hearing; that is, frequencies above approximately 20,000 cycles per second. Since the laws of sound which are valid for the audible range are also valid in the ultrasonic range and since the wave length of ultrasonics is much shorter than that of audible sound, ultrasonic has proved very valuable in the calculation of both the velocity and the absorption coefficient of sound in various media. This is especially notable in the case of liquids, where the velocity of sound is much …

A Study Of The Emission And Absorption Spectra Of Nacl And Kcl Between 100 A And 1000 A, Paul Henry Blackmon

Masters Theses

"This investigation was begun with the idea of obtaining the emission and absorption spectra of NaCl and KCl in the region between 100 A and 1000 A. From these data, it is hoped that useful information concerning the energy levels of these two substances may be obtained.

The vacuum ultraviolet region is rather difficult to investigate because of the necessity of removing all air, lenses and other absorbing material from the light path. Many writers have enumerated the problems involved and some have indicated that much work still needs to be done in the vacuum ultraviolet.

In order to do …

Coloration Of Glass By High Energy Radiation, Thomas L. Nickens

Masters Theses

"Purpose of Investigation: One of the objects of this investigation is to determine the amount of CeO₂ required to prevent the discoloration of glass when exposed to gamma radiation. By discoloration, it is meant that there has been a change in the absorption bands of visible light. Another objective is an attempt to prevent the coloration by the introduction of two oxides not previously used. Finally, a theory is presented which could explain why glass containing CeO₂ does not change color upon irradiation by gamma rays"--Introduction, page 1.

Determination Of The Thermal Conductivity Of Sodium Chloride At Elevated Temperatures, Harold Robert Weisbrod

Masters Theses

"The purpose of this research is to investigate possible methods of determining the thermal conductivity of small poorly conducting samples at elevated temperatures, and, further, to assemble a suitable apparatus, followed by measurement of thermal conductivity of one or more cubic lattice samples.

Basic requirements of the apparatus are few. It is first required that the measurement of thermal conductivity be made over a considerable range temperature. It is also preferred that the basic apparatus be placed in a vacuum where undesirable heat flow by convection is eliminated and air corrodible samples are preserved.

The apparatus must use only the …

A Model For X-Ray Scattering From A Free-Volume Liquid, Charles A. Hewett

Masters Theses

"Investigation of the diffraction of x-rays by liquids was begun soon after the well-known work of Friedrich, Knipping, and Laue proved to be of value in supplying information as to the arrangement of atoms in crystalline matter. Friedrich in 1913 reported x-ray diffraction patterns of Canadian Balsam, paraffin, and amber; three years later Debye and Scherrer, in their work on benzene, (among other liquids investigated) showed that the diffraction phenomenon exhibited was one of interference. Still later, in 1922, Keesom and de Smedt reported similar investigations carried out on argon, nitrogen, and oxygen in the liquid state, the results of …

A Linear Polymer X-Ray Scattering Model, Bernard Cohen

Masters Theses

"In the development of X-ray scattering intensity curves physical models are necessary for the theoretical mathematical development involved. The purpose of this paper is the development of a physical model suitable for X-ray diffraction analysis or a linear polymer.

X-ray intensity patterns may be used to give a greater insight as to the atomic structure, configuration or atoms, molecular weight, and therefore a greater knowledge of the structure of matter, both microscopic and macroscopic. The converse may sometimes be used. An atom or molecular model is constructed, from this model X-ray scattering curves may be derived. These curves may be …

The Fluorescence Of Uranium In Solid Solution, Robert Emmett Kelly

Masters Theses

"The fluorescence of uranium finds its greatest application in the so-called "bead test" which is a method of qualitative analysis. In the form of a bead, the uranium is in solid solution, and if the proper chemical solvent is used, the bead will fluoresce under ultraviolet radiation.

In the systematic separation of the metallic elements, uranium is associated with the aluminum group in that it is not precipitated by hydrogen sulfide in 0.3 N H ion but is precipitated by ammonium hydroxide and ammonium sulfide. In the analytical scheme, uranium acts like beryllium. This process of detection is sometimes tedious …

The Partition Function Of Silver, Ralph H. Lilienkamp

Masters Theses

"The study of the thermodynamic properties of solids at low temperatures has shown that most theories either break down or become too cumbersome.

A theory based upon a crystal lattice of atoms gives the best physical picture of a solid. Fisher has developed partition functions from this theory for the simple cubic, body-centered cubic, and the face-centered cubic lattices. In his paper Fisher gave three partition functions of increasing complexity and accuracy for each of the three lattices. In this paper the three partition functions for a face-centered cubic lattice shall be applied to silver and compared.

The Helmholtz free …

Integrated Scattering Of Microwaves By Small Metal Spheres, A. L. Merts

Masters Theses

"When electromagnetic radiation falls upon a material body of any kind, the associated electric field induces periodic oscillations of the electrons of the material synchronous with the incident radiation. The material serves as a secondary source and emits energy in the form of scattered radiation with a frequency equal to that of the incident electromagnetic wave. The polarization and intensity of the scattered radiation are determined by the size, shape, electric constants, and interactions among the scattering elements.

The scattering of electromagnetic waves is an old problem in physics. Such names as Rayleigh, Debye, and Mie have become associated with …

An Application Of The Atomic Distribution Function Of Liquid Mercury, Robert Lee Choate

Masters Theses

"The study of liquids and the knowledge of an adequate description of liquid structure have not advanced as rapidly as it has in the case of solids and gases. In a perfect crystal, the atoms or molecules are held in equilibrium positions by strong intermolecular forces. There are vibrations about these positions, but the translational energy is negligible. The molecules of an ideal gas move independently of each other and the intermolecular potential energy may be neglected. For each of these cases it is possible to derive a partition function from which the properties of the state can be readily …

Square Wave Modulation, Richard Henry Duncan

Masters Theses

"Modulation of a radio frequency carrier can be defined as the variation of some wave parameter such as amplitude, frequency, or phase, in accordance with intelligence to be transmitted. An unmodulated carrier is simply a continuous sine wave and contains no information other than the fact that the transmitter has been turned on. The spectrum of an unmodulated signal consists of a single frequency. Any type of modulation is characterized by the appearance of additional frequencies, known as sidebands. One of the fundamental problems in radio engineering is to reduce the number of sidebands to a minimum and still adequately …

The Completion, Adjustment, And Operation Of A Grazing Incidence Vacuum Ultraviolet Spectrograph, William Clinton Johnson-Chamberlain

Masters Theses

"Most gases, and particularly oxygen and nitrogen, are nearly opaque to radiation in the region from about 1800 Å downward to about 2 Å and hence, for spectroscopic work in this region, the removal of these gases is mandatory. Popular usage generally refers to the range mentioned above as the vacuum ultraviolet. That there remains much experimental work to be done in the vacuum ultraviolet has been pointed out by Boyce in his exhaustive survey of vacuum ultraviolet spectroscopy. In order to fill in some of these gaps, Mr. L. H. Chapin, in the, spring of 1950, undertook the construction …

Torsional Modulus Of Rupture Of Thick-Walled Magnesium Alloy Fs-1 Tubing, Delbert R. Cox

Masters Theses

"Magnesium is taking a more prominent position in the structure of aircraft, and because of this, it is important that the mechanical properties of the material be understood more fully. In the high speeds of today, the tendency is toward the use of thick-walled tubing instead of the thin-walled tubing with stiffening structures. For this reason, it is of interest to note the characteristics of thick-walled tubing when subjected to torsion.

This thesis was first suggested by a circular letter on proposed thesis titles from the Commanding General, Air Materiel Command, Wright-Patterson Air Force Base, Dayton, Ohio. When interest was …

A Light Source To Be Used With A Vacuum Spectrograph, Roy George Woodle Jr.

Masters Theses

"A grazing incidence vacuum grating spectrograph for use in the vacuum ultraviolet was designed and partially constructed by Mr. L. H. Chapin, as a research project for a Master’s Degree. This instrument is designed to photograph the region of the spectrum from 100 Å to 1000 Å. As Boyce pointed out in his exhaustive review, there is much important observational work to be done in this region.

The author of this paper has undertaken to develop a satisfactory source for the region from 100 Å to 1000 Å. This is part of a project to photograph the emission and absorption …

A Lead Sulfide Near Infrared Detection System, William V. Cummings Jr.

Masters Theses

"The infrared region of the spectrum is conveniently divided into the near infrared, which extends from the red end of the visible to about 25 microns, and the far infrared, which continues to an ill-defined division point of approximately 1,000 microns. The near infrared region has been further subdivided on the basis of instrumental techniques so that the particular portion of the spectrum consisting of radiations of wave length up to 3 microns has become known as the photoelectric infrared.

Several types of detection instruments have been designed and perfected for work in the photoelectric region, but new methods and …

A Correlation Function For Liquid Argon, Walter Graham

Masters Theses

"X-ray scattering patterns have given considerable information concerning atomic distributions in matter, both crystalline and amorphous. Work on the diffraction of x-rays by crystals was begun in 1912 by Friedrich, Knipping, and Laue, and much valuable information concerning the arrangement of atoms in crystals has been supplied by this method. Diffraction of x-rays by gases was studied as early as 1911, and work in this field has given information concerning the arrangement of atoms in molecules and electron distribution in atoms. Work on the diffraction of x-rays by liquids was begun by Friedrich who obtained diffraction patterns of Canada Balsam, …

The Energy Levels Of Potassium Chloride, Clifford L. Adams

Masters Theses

"An understanding of the electronic energy states of solids has long been considered of importance. And the energy levels of the alkali halides have been the subject of much study in recent years. The present work is an attempt to set up an energy-level diagram for potassium chloride"--Introduction, page 1.

The Theory Of The Specific Heat Of A Body Centered Cubic Lattice, Curtis Cleveland Webster

Masters Theses

"In normal crystalline solids the atoms are at rest in their lattice points at absolute zero of temperature. Increasing the temperature of the crystal increases the motion of the atoms about their lattice points. Approximately, each atom or ion may be treated as a harmonic oscillator. then from the equations of motion of the atoms, by the Born-von Karman theory of specific heats, the normal modes of vibration of the lattice can be expressed as the roots of a secular determinant. Application of this theory to determine the thermodynamic properties of crystals has resulted either in solutions that are inaccurate …

The Theory Of The Specific Heat Of A Face-Centered Cubic Lattice, Charles Robert Bonnell

Masters Theses

"It is generally accepted that a normal crystalline solid can be pictured at absolute zero as an assembly of atoms at rest arranged at periodic lattice points. Since at higher temperatures each molecule becomes a harmonic oscillator about its lattice point, it is necessary to know the distribution of normal modes of vibration in order to calculate the thermodynamic properties of the lattice...Many approaches have been made to get a simple solution of the problem, but either accuracy is sacrificed for simplicity, or the solutions demand a very considerable amount of labor. The classical theories failed to explain the change …

Intermolecular Potential Functions For Liquid Argon And Liquid Mercury, Richard H. Kerr

Masters Theses

"The purpose of this research is to obtain such intermolecular potential functions for liquid argon and liquid mercury by use of the experimental radial density functions available for these two liquids over a wide range of temperatures. We shall introduce the notion of a correlation between the motions of atoms in neighboring cells in a cell theory of liquid structure, and derive a theoretical radial density function involving the intermolecular potential function for a pair of atoms in the liquid. This radial density function, or as it is frequently termed, the atomic distribution function, applied to the experimental data should …

A Determination Of The Surface Tension Of Bismuth, Cadmium, Tin, And Lead, Edward Mckee Chandler

Masters Theses

"Various methods have been employed for the determination of surface tension including capillary rise, drop weight, maximum bubble pressure, sessile drops on flat surfaces, sessile bubbles formed underneath flat surfaces, and the shape of pendent drops. Each method is subject to characteristic advantages and disadvantages. Only two of these will be discussed. The method of maximum bubble pressure allows the formation of a fresh surface for every bubble but does not permit the study of a given sample over a period of time. The sessile drop in direct contrast, allows the observation of the same sample over any period of …

A Grazing Incidence Vacuum Grating Spectrograph For Far Ultra Violet Spectroscopy, Lawrey Huber Chapin

Masters Theses

"Spectroscopy, in the region of the far ultraviolet from 100 Angstroms to 1000 Angstroms, requires special equipment and techniques, inasmuch as these wavelengths are highly absorbed by air. Many gases have resonant frequencies corresponding to the wavelengths mentioned and hence absorption bands appear in the spectrograms obtained by using spectrographs for the visible region. One solution of the problem of obtaining data in this region is to construct a spectrograph from which all intervening gas molecules have been removed, thus eliminating the absorbing material. A vacuum of 10⁻⁴ mm. of mercury is necessary to reduce the absorption to a value …

The Reflection Coefficient At The Truncated Corner Of A Rectangular Wave Guide, John Raymond Barcroft

Masters Theses

"The term wave guide refers to a hollow conducting tube (usually of rectangular or circular cross section) filled with a dielectric (or vacuum) and used for the transmission of electromagnetic waves. We shall consider the guide to be bounded by a perfect conductor and to be filled with a lossless homogeneous isotropic dielectric (or vacuum). The electromagnetic wave in the guide must of course satisfy Maxwell's equation. It must also satisfy the boundary condition that there be no tangential component of electric field at the surface of the conductor. If the electromagnetic waves traveling along the guide meet a discontinuity …

Application Of Electrical Prospecting Methods To Two Types Of Sulphide Ore Deposits, Robert Van Nostrand

Masters Theses

"Although certain types of sulphide ores, especially those near the surface of the earth, lend themselves very well to electrical prospecting methods, quite the opposite is true of the extensive deposits of the type found in the Mississippi River Valley. The purpose of this investigation was to discover additional facts concerning two distinct types of sulphide ores, and therefrom to develop a new technique which would be applicable to prospecting for the lead and zinc deposits found in the Mississippi Valley"--Introduction, page 1.

Plateau Characteristics Of Geiger Counters With Respect To Different Gas Mixtures And Pressures, Ralph E. Lee

Masters Theses

"The section of a Geiger Counter is characterized by the so-called plateau curve. In this curve the counting rate of a given counter is plotted as a function of voltage, when the gas which it contains and the radiation to which it is exposed are both kept the same. These curves are characterized by a rapid rise beyond the starting potential (potential at which the counter begins to respond) until a more or less flat region is reached. This flat region is called the plateau of the curve. The slope and width of the plateau curve are dependent upon the …

A Determination Of The Surface Tension Of Tin In The Solid State, Charles Merton Rice

Masters Theses

"Many studies have been made on the surface tension of metals but almost exclusively in the liquid state. Information on metals in the solid state is needed in pure physics to test theories of cohesion and in physical metallurgy to explain sintering. The common approach to the problem of surface tension in the solid state is to hang a weight on a thin wire or leaf of metal and then heat this weighted sample to a temperature at which flow is appreciable. The shrinkage or stretch of the sample is then a measure of the surface tension. Of the recent …

The Effect Of Spontaneous Crystallization Of Some Inorganic Compounds At The Critical Temperature Of Their Solvents, John William Buttrey

Masters Theses

"For many years the phenomena which occur at the critical temperature of liquids have been investigated. And since 1912, when Laue and other discovered that a beam of x-rays could be made to yield a diffraction pattern by passing it through a crystal, scientists have been attempting to change the x-ray pattern for various crystals by somehow changing the arrangement of the atoms in the crystal lattice. Harvalik has already shown that crystallization occurs when a solvent reaches the critical point and his work indicates that under these conditions of crystallization there is a change in the crystal pattern. The …

A Microwave Polarimeter, Alfred E. Schwaneke

Masters Theses

"The dissertation on the following pages may read more like a construction article than an approach to a study of physical phenomena. If so, its purpose is clearly defined. this subject has been studied little from an experimental viewpoint, so one of the main objectives of this writing is to describe the instrument so others may read the article and reproduce this or an equivalent device without a great amount of reading and searching for information on just how to fabricate and mount the parts. No single book or article that I know of covers the inexpensive construction of such …

Hysteresis Loss Of Supermalloy At Different Temperatures, Chester Ray Holland

Masters Theses

"The object of this investigation was to measure the hysteresis loss of supermalloy at different temperatures, and to see if temperature had any effect on hysteresis loss and permeability. The maximum magnetizing current was held constant for all temperatures"--Introduction, page 1.