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Effect Of Environmental Hydrogen Pressure On The Hydrogen Yield From X‐Irradiated Polyethylenes, Otto H. Hill, R. Pat Lightfoot

Physics Faculty Research & Creative Works

An experimental assembly incorporating a capacitance‐type, differential pressure transducer, which provides resolutions of 3 x 10−4 torr at pressures extending to 30 torr, has been employed to monitor the effect of hydrogen environmental pressure on the hydrogen yield from x‐irradiated polyethylene's. Contrary to the observations of previous investigators, the hydrogen yield is found to be independent of hydrogen environmental pressures extending over the critical range up to at least 30 torr. It is demonstrated that neglecting the temperature and density gradients inherent in closed‐volume irradiation assemblies employing cryogenic traps to separate liberated gases into condensable and non condensable fractions may …

A Calorimetric Study Of The Effects Of Surface Energy In A Type Ii Superconductor, Robert Rex Rice

Doctoral Dissertations

"A calorimetric study of the effects of the interphase surface free energy has been conducted on ellipsoidal samples of first and second kind superconductors. The measurements were performed using a specially designed magnetization calorimeter by two different techniques. The measurements were made on lead, tin, lead-4at%thallium, and tin-6at% indium. The results confirm the existence and experted sign of the surface energy in a well annealed lead-4at%thallium sample, and indicate that the interphase surface energy in lead and tin is too small to be directly detected by this method. The measured latent heats of transition of lead and tin agree well …

A Study Of The Afterglow Of An R-F Excited Mercury Discharge, James A. Aubrecht

Masters Theses

"The short duration afterglow of an r-f discharge in mercury has been examined versus ground state mercury atom density and r-f power. The intensity of the 5771, 5462, 4360, 4079, 4047, 3907, 3651/56, 3342, and 3127/32Å atomic mercury lines were observed to decay as a function of time after the shut off of the active discharge. At temperatures below 333⁰K, all atomic lines decayed exponentially, and no molecular emission was observed. From 333⁰K to 423⁰K, the atomic lines were observed to decay rapidly initially, then exhibit an enhancement effect in intensity which was produced by metastable atom collisions, and finally, …

A Theoretical Investigation Of Elastic And Voigt Transient Spherical Waves, And Plane Three-Element Viscoelastic Waves, Edward Hornsey

Doctoral Dissertations

"A mathematical model of explosive generated waves in rock is needed in many areas of engineering endeavor. Investigations to date have been unsuccessful in obtaining a model that satisfactorily represents real wave phenomena at all radial distances and in all of the important characteristics.

In this investigation, spherical waves in elastic and Voigt media were investigated. Series solutions for plane waves in a three-element viscoelastic medium were obtained. A dual exponential pressure pulse, P(t) = P_o (e^-αt-e^-ßt) was assumed because it can exhibit significant features of real pressure pulses while avoiding instantaneous rise time, which …

A Study Of An Electric Method To Excite And Detect Acoustic Waves In Solids, John H. Stevens

Masters Theses

"This experiment has demonstrated that it is possible to generate pulses of acoustic waves in an aluminum single crystal by the direct use of the tensile stress associated with an electric field at the surface of a conductor, and it is possible to detect these waves with a biased, capacitive pickup transducer"--Abstract, page ii.

A Study Of The Molecular Emission And Of The Life Times Of The Metastable States In The Afterglow Spectrum Of A Mercury Discharge, Bruce M. Whitcomb

Masters Theses

"Two methods of studying the spectrum in the early afterglow of a pure mercury sample are discussed. Using a time-sampling technique, information about the intensity of the spectrum as a function of time in the afterglow can be obtained. The intensities of two molecular bands, centered at 3350A and 4850A, are studied. The method of formation of the diatomic mercury molecule and the emission of radiation in the two bands are shown to be density dependent. Mechanisms are presented which explain both the molecular formation and the radiation in the two bands. In an absorption study, the half-lives of the …

Theory Of Rbe For Heavy Ion Bombardment Of Dry Enzymes And Viruses, J. J. Butts, Robert Katz

Robert Katz Publications

The response of dry enzymes and viruses to heavy ion bombardment may be predicted from their response to γ-irradiation (and no further knowledge of their size and structure). The molecules are approximated as point particles whose response to ionization is the same for heavy ion bombardment as for γ-rays. From the δ-ray distribution formula and an extrapolated range-energy relation for electrons, the radial distribution of secondary ionization energy may be found. Under this dosage distribution the inactivation probability may be found as a function of radial distance from the ion's path, and then may be integrated over all space to …

Geophysical Institute Annual Report 1966-67, University Of Alaska Fairbanks. Geophysical Institute

GI Reports

The 1966–67 Geophysical Institute Annual Report presents an overview of the year’s scientific research achievements across the Institute’s disciplines, alongside operational summaries covering finances, administrative changes, and other key activities.

Kilocycle Range Dislocation Damping In Dilute Magnesium Alloy Single Crystals, Robert Ray Nothdurft

Doctoral Dissertations

"The kilocycle range dislocation damping and Young's modulus of single crystals of magnesium and single crystals of magnesium containing small additions of lithium, zinc, or aluminum have been studied as a function of strain amplitude, temperature, and time during annealing and following a high strain amplitude vibration. The data are compared to the Granato-Lücke theory of dislocation damping, the Granato-Hikata-Lücke theory for the recovery of damping following plastic deformation, and the Yamafuji-Bauer theory for the recovery of damping following a high strain amplitude vibration. Reasonable qualitative agreement is obtained between the Granato-Lücke theory and the observed dependence of the damping …

High Frequency Ferroelectric Properties Of The Bifeo₃-Pbtio₃-Pbzro₃ Ternary System, Robert Travis Smith

Doctoral Dissertations

"High temperature dielectric measurements have been performed on the ferroelectric and antiferroelectric perovskitic polycrystalline solid solutions in the BiFeO₃-PbTiO₃-PbZrO₃ ternary system. The data were taken in the UHF frequency range with the use of a slotted line and specially constructed sample holder capable of operation at temperatures in excess of 800°C.

The Curie points have been found to occur at progressively higher temperatures with the increase of BiFeO₃ content in the solutions except in phase transition regions where minima can occur. The dielectric constants at the Curie temperatures have been found to decrease with …

Equation Of State Of Sodium Chloride, Daniel L. Decker

Faculty Publications

Because of many requests, I wish to publish the following numerical table of results for the equation of state of NaCl as calculated in an earlier paper1 along with a few comments on various proposed equations for NaCl. Table I gives the pressure in kilobars at the corresponding values of t.a/ao and temperature in the appropriate row and column. The parameter t.a/ao is the fractional compression of the lattice parameter where the standard value ao is the appropriate lattice parameter at zero pressure and 25°C. The increments between the values given in the table were chosen such that one can …

Optical And Electron-Paramagnetic Resonance Studies Of Sodium-Fluoride, Ronald Allen Andrews

Wayne State University Dissertations

No abstract provided.

Simulated Radioactivity, Robert Katz, J. J. Butts

Robert Katz Publications

An experiment to simulate radioactive decay is easily performed with a random-number generator or a set of random numbers. The nuclei are imagined to be indexed consecutively. The initial appearance of the index number of a particular nucleus is interpreted as a signal that it has disintegrated. The number of surviving nuclei is an exponential function of the number of draws, and represents the radioactive decay law, with fluctuations. This procedure is a precise realization of the conventional probabilistic derivation of the radioactive decay law if, indeed, the random number generator is truly unbiased.

On The Symmetry Of Slater Determinantal Wavefunctions, Gordon A. Gallup

Gordon Gallup Publications

A method involving the use of characteristic polynomials of irreducible representation matrices of groups and yielding the symmetry species of Slater determinantal functions is given. The necessary polynomials have been calculated for the commonly occurring symmetry groups and are listed to supplement the usual character tables. ©1966 American Institute of Physics

Model Of Electron Correlation In Solids, Everett G. Larson, Walter R. Thorson

Faculty Publications

The usual Hartree-Fock model (energy-band theory) does not always give an adequate description of electronic structure in a solid, because it ignores the effects of electron correlation. It was shown first by Wigner that such a situation always develops in an electron ''gas'' at sufficiently low density; a solid structure described by ''resonance'' of Heitler-London pair bonds between electrons localized on neighboring atoms is then a good model of the system.The transition from a Bloch-type state to such a highly correlated state as a function of electron density (lattice parameter) is a problem of considerable interest for the theory of …

Surface-Wave Phenomena At A Water-Air Interface., Benjamin W. Woodward

Physics & Astronomy ETDs

The existence of a surface wave accompanying total internal reflection of light in a dielectric material was derived classically to satisfy boundary conditions at the surface. Using this fact, in 1929 J. Picht proposed a mechanism for total reflection that led to the conclusion that a finite ray of light would undergo a small translation at the boundary, parallel to the boundary and in the plane of incidence. In 1943 Goos and Hänchen made quantitative measurements of this translation or shift. Subsequently many theories have been advanced analyzing this phenomenon in detail, but as of this writing no other experimental …

8th Annual Meeting Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 8th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 8-9, 1966.

Study Of Some Solutions Of The One-Electron—Two-Center Problem For Heteronuclear Cases, L.Y. Wilson, Gordon A. Gallup

Gordon Gallup Publications

The Schrödinger equation for two nuclei and one electron has been solved for the first eight σ states of the system HeH^{2 +} , He₂³⁺, LiH^{3 +} , and LiHe^{4 +} . The resulting solutions are described and some of their properties are discussed. ©1966 American Institute of Physics

Self-Consistent-Field Calculation Of The Energy Of Heh +, Gordon A. Gallup, M.S. Mcknight

Gordon Gallup Publications

The use of the exact solutions of the one-electron—two-nucleus problem as a basis set of functions for SCF calculations is investigated for the HeH ⁺ ion. The calculations are made with both scaled and non-scaled functions. The best energy obtained here is –3.345 a.u. at an internuclear distance of 1.40 a.u. The conclusion is that these functions form an only moderately good basis set for such calculations. Their conditioning to the problem can only partially overcome their lack of completeness when continuum states are omitted. ©1966 American Institute of Physics

Pressure Calibration To 100 Kbar Based On The Compression Of Nacl, R. N. Jeffrey, J. Dean Barnett, H. B. Vanfleet, H. Tracy Hall

Faculty Publications

An independent determination has been made of the transformation pressures assigned to the high-pressure transformations in Ba and Bi which are generally used for calibration points. The metals were imbedded in NaCl, and the transitions were detected by the resistance change of the metal while the NaCl lattice parameter was simultaneously measured by x-ray diffraction. The NaCl compression values determined at the fixed points were related to pressure by reference to the semiempirical compression curve of Decker. The Ba I-II and Bi III-V transformations at room temperature were assigned thermodynamic equilibrium values of 53.3 ±1.2 kbar and 73.8 ±1.3 kbar, …

Angular Distribution Of Neutrons In Atmosphere Produced By Protons, Donald Stuart

Physics & Astronomy ETDs

In connection with the balloon flown directional neutron detector experiments in progress, the following theoretical problem presented itself. Find the angular distribution of neutrons incident upon a detector. This is investigated under varying conditions using a computor program prepared for this problem. Two models for the problem are considered in this paper. In the first model we choose the simplest conditions that approximate a possible physical situation. This consisted of considering that the system was completely isotropic. For certain altitudes this gave very good results as can be seen by the curves. Then modifications to the theory are discussed. This …

Geometrical Representations Of Relativistic Motion, Jeffrey H. Robbins

Physics & Astronomy ETDs

This investigation begins with the development of a transformation or mapping in velocity space of such a character that velocities are mapped into a quantity that adds linearly, while velocities add non-linearly according to the Einstein Law of Addition, and has no upper limit to its magnitude, i.e., when the speed of an object approaches that of light in a vacuum, this quantity becomes infinitely large. Kinematic relationships, in Newtonian form, for a particle undergoing acceleration, are developed in a frame of reference that remains attached to the particle using the new variable (W). It is found that relativistic energy …

Coulomb Excitation Of The Ytterbium Isotopes., John M. Palms

Physics & Astronomy ETDs

Coulomb excitation studies have been performed on the ytterbium isotopes 171, 172, 173, 174, and 176 using oxygen ions having energies up to 55 MeV. Resulting de-excitation gamma rays have been observed in particle coincidence with a NaI(Tl) detector and as single spectra with a Ge(Li) detector. The ground state rotational bands of the Yb171 and Yb173 isotopes have been excited to the 13/2- level. The 13/2- and 11/2-levels of both nuclei have not been reported before. In addition to the transitions from the ground state band, gamma rays were observed from Yb171 and Yb173 coming from other bands. A …

Investigation Of Propagation Of Light Through Gases And Air Structures Treated As Wave Guides., Richard W. Christiansen

Physics & Astronomy ETDs

The equations defining the propagation of electromagnetic radiation down cylindrical dielectric wave guides are developed. A Helium-Neon laser is used to illuminate several different cylindrical wave guides. The propagation nodes are recorded on photographic plates. Using the field equations, the electric field on a transverse plane is plotted and used to explain some HE_im modes observed. The patterns recorded on the photographic plates are described and discussed in terms of the propagation modes.

Measurements Of Continuous X-Ray Spectra With A Scintillation Spectrometer, Ellery Strom

Physics & Astronomy ETDs

Scintillation spectrometer measurements were made of the x-ray spectra produced by a constant-potential x-ray unit operating at 100, 150, 200, 250, and 300 kV. An attempt was made to measure the absolute intensity as well as the spectral distribution. In order to reduce the counting rate to a measureable level, it was necessary to place the thallium-activated sodium-iodide detector 50 meters from the target. Since the air attenuation was quite large, measurements were made both in air and in helium. In order to contain the helium, an Orangeburg pipe was employed, and its effect on the spectra was determined by …

Some Factors Which Influence The Intensity And Resolution Of Beams In Neutron Diffractometers, Robert G. Wenzel

Physics & Astronomy ETDs

The problems of the intensity and resolution of a neutron diffractometer are considered, both for elastic and inelastic scattering studies. The considerations are applied to the choice of parameters for a new diffractometer. First to be taken up is the manner in which the intensity of a diffraction monochromating system varies with its collimators, which affects both kinds of studies. A model is chosen and used to derive an expression tor the intensity. The expression is checked experimentally and found not be be valid over the range of collimators available. However, over a smaller range, such as those collimators which …

High Frequency Scattering From A Schroedinger Square Well, Robert R. Thede

Physics & Astronomy ETDs

Many observations have been made of the enhanced back scattering of light waves from water droplets. This phenomenon, commonly referred to as the glory, is inexplicable in terms of ray optics. Calculations based upon the Mie series solution to the scattering of an electromagnetic plane wave from a dielectric sphere suggest that this pronounced scattering is due to surface waves which travel around the sphere and are emitted in phase preferentially in the forward and backward direction. These results have also been verified experimentally by examining the backscattered light from a water droplet.

X-Ray Diffraction And Electron Microscopy Studies Of Glasses Containing Antimony, Sadek Momtaz Tadross

Archived Theses and Dissertations

No abstract provided.

Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds. The application of herbicides has thus become a regular agricultural and ecological practice.

Simultaneous Flow Of Heat And Water In Plant Tissue, Gaylon Sanford Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although biological phenomena may be partially described in a general way without the use of mathematics and physics, the experimental results may be more meaningful if they are analyzed on the basis of physical and mathematical laws. The complexity of biological systems has made the application to them of mathematics and physics rather difficult, and only recently has much progress been made. Although it has yet been possible to describe only a few simple biological systems by actual equations, a great deal of qualitative information may be obtained by applying physics and mathematics. Russell (1960, p. 439) said

In principle …