Physical Sciences and Mathematics Commons^™

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 …

A Study Of Atmospheric Ozone Near The Surface Of The Earth, Irby Gerald Bowen

Physics & Astronomy ETDs

It is the primary purpose of this thesis to describe the method used for measuring ozone at the earth’s surface. There is also a report on a brief series of surface ozone measurements. An attempt is made at a preliminary explanation on the basis of meteorological conditions of the diurnal variations which were found.

A New Method Of Measuring The Intensity Of The Zodiacal Light, Raymond Grenchik

Physics & Astronomy ETDs

The two theories that have been presented for the zodiacal light show that it is due to light scattered (and perhaps emitted) from an extensive lenticular cloud of particles lying in the plane of the ecliptic. The basic difference of the two theories is the position of the center of this cloud. One, the planetary theory, places the sun at the center of this cloud. The other, the atmospheric theory, places the earth at the center of the cloud.

A Cosmic Ray Experiment Using Nuclear Photographic Emulsions, Mercedes Merner

Physics & Astronomy ETDs

A "camera" containing thirty-six nuclear plates was carried into the upper atmosphere to an altitude of twelve miles by a free balloon flight. These plates were arranged in four groups separated by successively thicker layers of steel so that nuclear events under different amounts of matter could be observed.

After recovery of the equipment these plates were developed and examined under the microscope. Four plates were selected for intensive investigation, and data was collected on the tracks found in the areas examined.

In the first part of this report nuclear plate technique will be discussed in general together with the …

A Nuclear Magnetic Resonance Absorption Experiment, Richard Runge

Physics & Astronomy ETDs

In nuclear magnetic resonance absorption work, the detection of the absorption of energy by protons situated in a steady strong magnetic field and subject to a weak radiofrequency (RF) magnetic field is attempted. The protons are present in a sample placed inside an RF coil. A radiofrequency current, present in this coil, produces a rapidly oscillating magnetic field which is capable of supplying energy to the system of protons in the steady strong magnetic field. This absorption of energy by the protons alters their relative numerical distribution among the energy levels available to them.

Binocular Space Perception, Kenneth N. Ogle

Journal of the Minnesota Academy of Science

No abstract provided.

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 …

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 …

Use Of Motion Pictures In Laboratory Dynamical Studies, Carl Bailey, Jaan Jurisson, M. Eugene Rudd

M. Eugene Rudd Publications

In student laboratory experiments in dynamics, as, for example, Newton's second law of motion or the conservation of momentum, it is, of course, highly desirable to allow motion with the least possible constraint and to observe the displacements of moving parts without using perturbing markers. This circumstance has led us to use motion pictures in the student laboratory for quantitative observation of rapid dynamic processes, a technique which is used in a well-known textbook.' The photographic method combines maximum freedom of movement with accurate observation of position as a function of time, if the camera frame speed is sufficiently high. …

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.

A Study Of Variations In Cosmic Ray Intensity Due To The Shifting Of Isobaric Layers In The Stratosphere, Frederick Herbert Martens

Physics & Astronomy ETDs

This investigation is an attempt to correlate variations in cosmic ray intensity with shifts of the isobaric layers in the stratosphere on the basis of the change in path length traveled by radioactive mesotrans, and in consideration of ordinary mass absorption of the air along the path.

Physical Properties Of Ellis County Adobe, William G. Read

Master's Theses

Houses made of soil have been built for centuries, but until recently the trend had been away from soil to some other building material. Now, however, adobe is again beginning to be recognized as a satisfactory, reliable building material for our time. Recently, especially in the southwestern part of the United States, a surprising number of dwellers have turned again to earth for their building material. They are following in the footsteps of the early settlers, who constructed many missions and other buildings from sun-dried earth. Many of these buildings, although aged, are still in use or may be viewed …

Determination Of The Proper Mixtures Of Ellis County Soils For Adobe Construction, Buster W. Read

Master's Theses

The purpose of this investigation was to determine whether the soils of Ellis County could be used to form waterproof soil blocks that might be used for construction. In the investigation eight soils found in the county were employed and several stabilizers added to each in varying amounts to determine if the specific soils could be rendered waterproof. Several types of paint finishes were tested. The work was divided into three main parts: (1) Survey of Ellis County Soils; (2) Selection of soil material with respect to shrinkage; and (3) Treatment of soils with respect to waterproofing.

United States Patent: Antenna Strain Insulator, Robert Katz

Robert Katz Publications

The invention to be hereinafter described relates to insulators and more particularly to strain insulators for wire antennas.

It has long been common practice to use with antenna wires on airplanes the well known porcelain or ceramic insulator, the wire ends being looped through or about the insulator, and brought back and twisted about the wire to tie, anchor or securely attach or fasten the insulator to the antenna. The produces small wire-end surfaces or other small wire surfaces, where the wires are would or twisted, which under certain atmospheric conditions are favorable to corona discharges. When the corona discharge …

Radioactivity Of The Pre-Cambrian Section Of The Bourbon, Missouri, Well Core By Measurement Of The Total Hard Gamma Radiation, Paul E. Damon

Masters Theses

"In December of 1947 Mr. Robert Van Nostrand and the writer became interested in the problem of the distribution of natural radioactivity and the applications of radioactivity to geology. A cooperative survey of the literature on the subject was undertaken. Later the writer decided to follow up the survey with a research project. Consultations with Dr. Z. V. Harvalik of the Missouri School of Mines Physics Department, and Dr. E. L. Clark and Mr. O. M. Bishop of the Missouri Geological Survey, followed. The nature of the project was evolved when Dr. Clark, with the consent of the U. S. …

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.

The Kerr Electro-Optic Effect In Plastic Materials Transmitting Infra-Red Radiation, James Edson Dueker

Masters Theses

"Much work has been done investigating the Kerr Electro-Optic effect and what physical properties of a substance lead to the occurrence of the phenomenon. Information now available indicates a relationship between molecular shape and orientation with the Kerr Effect, hence any added information increases the possibility for finding the exact relationship and the molecular structure of substances. The Kerr Effect, has been used in a number of applications other than for the study of molecular construction of matter. Many applications have been made to form Electro-Optic shutters. This field of work has been increased to include light flash production and …

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 …

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 Device For Determining The Electrical Characteristics Of Common Industrial Electronic Tubes, Addison Dabney Campbell

Master's Theses

Many tube checkers designed for radio receiving tubes have been developed . Most of the devices for test­ ing these tubes do little more than check the emission of the cathode. This is usually accomplished by applying alternating voltage to the plate of the tube undergoing the test and reading the direct-current component of the plate current . In this case, the control grid bias volt­ age is usually set at a fixed value although sometimes facilities for varying the bias are provided. If the tube is of the multi-grid type, all the grids except the control grid are connected …

Thermal Conductivity Of Air Layers, Zaboj V. Harvalik

Journal of the Minnesota Academy of Science

No abstract provided.

Corona Discharge From Antenna Wire: A First Partial Report, Robert Katz

Robert Katz Publications

Purpose: 1. To examine the conditions for corona at the surface of a wire. This report is a theoretical discussion. No test procedure was used.

Conclusions:
1. Calculation of the gradient at the surface of the fixed-wire liaison antenna (bare copperweld, .040" diameter) on the B-17 airplane indicates that it is of the order of 200 times the gradient measured at the top generating voltmeter.
2. Further work will be done by the Special Devices Branch in an attempt to determine the conditions under which insulated wire goes into corona.

X-Ray Inspection Of Castings (Army Air Forces' Requirements), Robert Katz

Robert Katz Publications

The author contributed a brief account of the radiographic practices necessary to comply with government specifications to a round table discussion on inspection methods at the last American Society for Metals Convention, and later was able to release for publication in Metal Progress a full set of the radiographic standards set up about a year ago to govern acceptance of structural castings for airplanes. Representaive negatives are reproduced in this article. Those eliminated are either of similar defects which did not register strong enough to appear on an engraving without retouching, or of defects readily observed by visual inspection without …

A Generating Voltmeter Of Wide Sensitivity Range For Measuring Atmospheric Potential Gradients, Herschel Roy Snodgrass

Physics & Astronomy ETDs

The specific need for the present instrument arose out of a consideration of the significant results that might be obtained through a coordination of reliable data on potential gradients under various cloud formations with the accompanying fast motion cloud photographs. The characteristics most desired were: (1) the continuous measurement of both the magnitude and polarity of the surface potential gradients over a wide range of values, from normal fair weather gradients of 0 to +300 volts per meter to thunderstorm gradients, possibly as high as 200,000 volts per meter; (2) easy portability; (3) resistance to harmful effects from rain, dust, …

Threshold Values For The Perception Of The Direction Of Frequency Modulation, Abe Pepinsky

Journal of the Minnesota Academy of Science

No abstract provided.

Characteristics Of Spectrographic Plates In The Ultra Violet Region Between 2300-2000a, R. G. Beck, L. Lundberg, Elmer S. Miller

Journal of the Minnesota Academy of Science

No abstract provided.

The Relative Influence Of Raw Material Components Upon The Thermal Expansion Of Vitreous Enamel., Robert C. Boyd

Electronic Theses and Dissertations

No abstract provided.

A Study Of The Effect Of An Equal Energy Spectrum Upon Metallic Selenium In Vacuo, George Butler Scott

Master's Theses

Since little has been found in the literature, on the effect of a actinic properties on the conductivity of metallic selenium and on its spectral response when possessing these properties, it was thought noteworthy to construct several selenium cells having low and medium dark resistances and to study them with a view of seeking some correlation between their conductivity characteristics and their prismatic response in vacuo.

The Propagation Of Ten Meter Radio Waves By Vertical And By Horizontal Dipole Antennas, James William Haddock

Master's Theses

Radio communication is made possible by means of energy that travels through space from the transmitter to the receiver in the form of electromagnetic waves. These waves move with the velocity of light and differ from visible light only in wave length or frequency. This radiant energy consists of a magnetic field and of an electrostatic field, at right angles to each other and also at right angles to the direction of propagation. Questions explored in this thesis include: 1. Is there a relation between the amount of reflected radio energy and the angle of polarization. 2. If so, which …

Radioactive Properties Of The Subterranean Waters Of Ellis County, Kansas., Verne Lippert

Master's Theses

Soon after the discovery of Becquerel rays in 1896, tests were made on ordinary matter to see if all matter were radioactive. Although there is evidence to show that all matter is radioactive, to a degree and under certain conditions, it has been found that the greater part of the observable effect is due to traces of radioactive material permeating all matter in general. Thus, radium and its products being the most active of radioactive substances, the surface of the earth is covered with traces of these radioactive substances but the amount varies from place to place. Moreover, determinations of …