Physics Commons^™

On The Theory Of Head Waves, Patrick Heelan

Research Resources

When a combined longitudinal and transverse disturbance, diverging from a localized source, strikes a plane boundary between two solid elastic media, several systems of head waves and second order boundary waves are generated, each associated with grazing incidence of one or the other of the reflected or refracted waves. Associated with grazing incidence of P ₁ P₂, the refracted P-wave, is the head wave system comprising P₁P₂P₁ (the "refracted wave" of seismic prospectors), and P₁P₂S₁ (a transverse head wave) in the upper medium, and P₁P_{2 …}

Apparatus For The Measurement Of Atmospheric Attenuation Of Light, John E. Lyon, Robert D. Woosley

Journal of the Arkansas Academy of Science

No abstract provided.

An Investigation Of The Effects Of Wave Propagations In An Infinite Membrane Upon The Motions Of Salt Particles On The Surface, Robert Talmadge Maupin

Electronic Theses and Dissertations

No abstract provided.

A Theoretical Formulation Of The Hammett Equation, Gordon A. Gallup, W.R. Gilkerson, M.M. Jones

Gordon Gallup Publications

A relation, which reduces to the form of Hammett's equation, has been derived. Reactions which can be assumed to be of the form ion-dipole or dipole-dipole have been considered. The logarithms of the ratios of rate constants were calculated and compared with experimental values in the form of Hammett's equation constants.

Internal Fissuring Of Wheat Due To Weathering, Max Milner, J. A. Shellenberger, M. R. Lee, Robert Katz

Robert Katz Publications

Radiographic technique developed at this Station for the determination of internal or hidden insect infestation in stored grain has proved to be useful for the detection of other physical anomalies in grains. Practical applications of this sort include the detection of cracked or broken kernels in rough rice (paddy) prior to milling as well as the extent of internal fracturing of certain grains such as maize due to uneven stresses arising from severe drying conditions. This communication deals with a condition of internal fissuring occurring in wheat due to weathering of the ripened grain in the field.

Hydrogen Bond Energies In Carboxylic Acids, M.M. Jones, W.R. Gilkerson, Gordon A. Gallup

Gordon Gallup Publications

A question of interest to the study of the chemisorption of carbon monoxide on iron is whether the carbon is desorbed with the same oxygen to which it was bonded prior to the adsorption. A mixture of C¹³O and CO¹⁸ in the desorbed gas in amounts greater than expected from normal abundance ratios shows that an intermolecular oxygen exchange occurs.

Chemical Reactions Near Equilibrium, W.R. Gilkerson, M.M. Jones, Gordon A. Gallup

Gordon Gallup Publications

In seeming contradiction to usual deductions from thermodynamics, it has been shown by De Donderi on the basis of his affinity function, by Prigogine² on the basis of the Chapman- Enskog model, and by Manes, Hofer, and Wellers using purely mathematical methods, that the rate of a chemical reaction close to equilibrium is directly proportional to the free energy difference between reactants and products. This relation may be shown to be a consequence of the theory of absolute reaction rates, also.

Radioactivity Of Eu152,154, Robert Katz, Milford R. Lee

Robert Katz Publications

Although the spectrographic analysis accompanying several enriched samarium isotopes from Oak Ridge contained <0.6 percent europium, some of the more intense internal conversion lines attributed to the disintegration of europium have been found photographically with neutron-activated samarium isotopes in a 180° focusing β-ray spectrograph.

Radiography Applied To Grain And Seeds, Max Milner, Milford R. Lee, Robert Katz

Robert Katz Publications

A radiographic method for the detection of internal insect infestation in grain by means of low energy radiation from a cobalt-target beryllium-window X-ray tube is described. The utility of the technic for inspection of wheat, corn, rice, and beans is illustrated with cuts made from original radiographs.

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 …

Investigation Of Penetrating Cosmic-Ray Showers In Water, George William Rollosson

Physics & Astronomy ETDs

In this investigation, some of the properties of the radiation which produces penetrating showers in its passage through matter are studied. Geiger techniques are used to measure the average distance over which the neutral radiation produces one penetrating shower. This distance, called collision length, is measured in water...

The collision length, on the other hand, is measured by placing the material near the apparatus and measuring the mean distance in which one shower is produced and eliminating from the observation any penetrating showers which may be produced subsequently either (a) by the original particle or (b) by the secondaries from …

An Experimental Investigation Of The Dead Time Of Geiger-Mueller Counters, Peter H. Jessner

Physics & Astronomy ETDs

As ever more sensitive and precise experiments are being performed with Geiger Counters, especially in cosmic ray research, the resolving power of these instruments assumes an ever increasing importance. With the present perfection of electronic circuitry, this resolving time has become largely a function of the dead time of the Geiger counter tube itself. It was therefore proposed to investigate methods of reducing this dead time. Only self-quenching counter tubes had to be considered in this connection since the dead time of all other types of Geiger counters is inherently longer.

A Sensitive Electronic Photometer Employing Negative Feedback, John Lee Pack

Physics & Astronomy ETDs

Purpose of the Instrument

The instrument to be described in these pages was tentatively intended to be used for the purpose of scanning the night sky automatically for investigations of the zodiacal light. It was to detect light below the noise level of a photomultiplier tube, to have linearity up to signals 100 times greater than the noise level, and to have a response time of about 10-4 seconds.

The Elastic Scattering Of Deuterons By Deuterons, Richard John Runge

Physics & Astronomy ETDs

The concern of this work is the calculation of elastic scattering of deuterons by deuterons. The solution of the problem will be given in the usual center of mass system of coordinates, the conversion of results from this to the laboratory system being standard. Since the deuteron itself consists of a neutron and a proton, the problem is thus one of four bodies. The nuclear three body problem of the scattering of a neutron by a deuteron has been treated by previous authors and we will have occasion to employ methods used by these authors extending them to the four …

Radioactive Disintegration, Robert Katz

Robert Katz Publications

The conventional development of parent-daughter relationships in radioactive disintegration follows the treatment given in Rutherford, Chadwick, and Ellis in which a trial solution of the differential equations appropriate to the process is proposed, and the arbitrary constants are evaluated by application of boundary conditions. At the senior-graduate level at which the first course in nuclear physics is usually taught, the following derivation is believed to be considerably more instructive.

An Experimental Investigation Of A Light Weight High Voltage Power Supply, James F. Tribby

Physics & Astronomy ETDs

This investigation is directed toward the development and design of an electronic high-voltage power supply. The method consists of obtaining a direct current of low intensity by periodically charging by means of a primary battery a group of capacitors in parallel combination and discharging them electronically in series. A stimulus to this investigation is provided by the need for a light-weight electronic current source operating at moderately high voltages which is stable and capable of maintaining a constant current of low intensity over a wide range of variation of the potential from a primary battery. In addition, a power supply …

A Differential Electronic Photometer And Polariscope With Negative Feedback, William Rogers

Physics & Astronomy ETDs

In connection which a program of research in the physics of the atmosphere, a need has arisen for a sensitive differential photometer which would be adaptable to balloon-borne operation. This paper describes a prototype of such an instrument. The present photometer is constructed for preliminary investigations to be carried out in the laboratory, but with light weight components used in the design except for the power supply and the main structural frame. Consideration is given to these latter features to the extent that the entire equipment is designed for operation from power sources which can be directly replaced by small …

An Experimental Determination Of The Distribution Of Core Location Of Extensive Air Showers, Jerre P. Moore

Physics & Astronomy ETDs

It is the purpose of this paper to investigate the distribution of the core location of extensive air showers striking near an array of liquid scintillators.

Determination Of The Shape And Position Of The Zodiacal Light By Use Of An Automatic Recording Method, James D.G. Lindsay

Physics & Astronomy ETDs

The problem was to determine the shape of the zodiacal light pyramid and also its position relative to the ecliptic using an automatic recording system. The main requirement was to be simplicity in the interpretation of data.

The Freezing Point Of Water In Puddled And Unpuddled Soils At Different Soil Moisture Tension Values, Robert B. Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique that will adequately describe the physical condition of water in the soil has long been desired by scientists. The method should include the effect of soluble materials on the osmotic pressure of the soil solution, and also the effect of surface force action between the soil and soil water.

Parker (8) demonstrated that the freezing point was reduced in the presence of finely divided material. This suggested the possibility of using the cryoscopic procedure to measure the physical condition of water soil. More recently, the introduction of Thermistors for accurate temperature measurement have made it desirable to investigate …

A Demonstration Of Various Procedures Used To Interest And Help Pupils To Understand Physics, O. M. Bjeldanes

Journal of the Minnesota Academy of Science

No abstract provided.

Modern Physics, Charles L. Critchfield

Journal of the Minnesota Academy of Science

No abstract provided.

Oxidation Of Silver As A Method Of Measuring Ozone Concentration, Lorne Maxwell Chanin

Physics & Astronomy ETDs

It has been found that, under certain conditions, a chemical reaction occurs between silver and ozone. The products of this reaction are silver oxides and oxygen. When heated to a certain temperature, the silver oxides are decomposed into silver and oxygen. If this reaction were produced, then the amount of oxygen resulting from the decomposition would be a measure of the amount of ozone originally present.

The Intensity Of Zodiacal Light, Allan F. Beck

Physics & Astronomy ETDs

The study of the intensities measured in the region of the zodiacal light, the second most important contributor to this light of the night sky after starlight has been subtracted, is the purpose of this paper.

Note Concerning Cloud Chamber Experiments With Positrons, H. M. Schwartz

Journal of the Arkansas Academy of Science

No abstract provided.

Statistical Fluctuation In Radioactive Phenomena, James A. Grundl

Bachelors’ Theses

It is the purpose of this thesis to present a method applicable to an intermediate laboratory course in Modern Physics of establishing the random nature of radioactive disintegrations. The method is fundamentally that used in 1910 by Rutherford and Geiger.

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 …