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The Alignment Procedure Of A Two Crystal Spectrometer, Jay W. Phippen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

For the sake of completeness, it was felt that a brief resume' of x-ray scattering theory as it affects the alignment procedure of a two crystal spectrometer would be beneficial.

X-ray diffraction from a single crystal slab.

W. L. Bragg (1912) tried the experiment of reflecting a beam of x-rays from the cleavage surface of a crystal and found on the photo-graphic plate a spot at the angle of reflection. He then replaced the photo graphic plate with an ionization chamber which he mounted so that it could be rotated about the axis upon which the reflecting crystal is …

Movement Of Atrazine In Soil Under Furrow Irrigation, Jyothi Veerabhadrappa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Movement of atrazine in response to furrow irrigations was studied using the samples of Timpanogos silt loam soil. Distribution in soil profile of surface applied herbicide was determined by drawing samples of water extracts through porous cylinders. Atrazine quantity was determined by spectrophotometer.

It was observed that the herbicide found in the water extracts was an indication of the quantity present in the soil. The herbicide moved readily with the applied water. Irreversible thermodynamic model could not be applied because of the initial and final boundary conditions. The pattern of movement was in conformity with the chromatographic theory.

The 233u Fission And Capture Cross Sections And Their Analysis At Low Engines, Delmar W. Bergen

Physics & Astronomy ETDs

The ²³³U fission and capture cross sections were measured using a nuclear-device neutron source and time-­of-flight techniques. Cross section data are presented from 20 to 10⁶ eV for fission and from 20 to 63 eV for fission + capture. The resonance region (20 eV to 63 eV) was fitted with both a single level function consisting of a sum of Breit-Wigner levels and the Reich and Moore multilevel function based on R matrix theory. The resulting resonance parameters are listed and discussed. In order to establish the validity of the resonance parameters derived from the multilevel fit, a …

Development Of A Method For Measuring Magneto-Optical Rotatory Dispersion, Donald K. Loving

Masters Theses

No abstract provided.

Low Temperature Sample Orienting Device With Two Degrees Of Freedom, David J. Sellmyer

David Sellmyer Publications

The purpose of this note is to describe a sample orienting device which has been used successfully at liquid helium temperatures to measure the high-field magnetoresistance of several single-crystal metallic compounds in a solenoidal field.

High‐Magnetic‐Field Studies Of Orthorhombic And Rhombohedral Al2−XFeXO3 Compounds, M. Schieber, Richard B. Frankel, N. A. Blum, S. Foner

Physics

Mössbauer and magnetic susceptibility experiments at temperatures down to 4.2°K and in external fields up to 140 kOe show orthorhombic Al_2−xFe_xO₃ (0.61.6Fe_0.4O₃ is paramagnetic above 80°K, and at 4.2°K exhibits a Mössbauer spectrum characteristic of a nonunique hyperfine field; the application of an external magnetic field produces a spectrum with an enhanced Δm=0 line which suggests a canted spin structure similar to that in the high‐temperature phase (T>260°K) of αFe₂O₃.

Pumping And Horsepower, R P. Harington

Journal of the Department of Agriculture, Western Australia, Series 4

WATER is vital to the survival of plants and animals and its availability will influence the site of the homestead and the farm layout generally.

This article describes some of the factors involved in the installation of a pumping outfit for domestic and stock requirements.

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 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.

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 …

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 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 …

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, …

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 …

Ferroelectric Properties Of Pbzro₃-Bifeo₃ Solid Solutions, Robert Gerson, Pen-Chu Chou, William Joseph James

Physics Faculty Research & Creative Works

Solid solutions of BiFeO and PbZrO₃ were investigated for crystallographic and dielectric properties. A new pseudocubic perovskite phase was found, which has been tentatively indexed as orthorhombic with the same unit cell as PbZrO₃ but with dielectric properties characteristic of a ferroelectric substance. The Curie point in this series of solid solutions has a minimum of about 155°C at a composition of about (PbZrO₃)_0.80 (BiFeO₃)_0.20, which at room temperature lies on the boundary between the orthorhombic antiferroelectric and the pseudocubic ferroelectric phases. This composition has a relative dielectric constant of 800 …

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 …

Magnetic Properties Of The Bifeo₃-Pbtio₃-Pbzro₃ Ternary System, James Ivan Latham

Doctoral Dissertations

"The magnetic susceptibility and spontaneous magnetic moment of the perovskitic, polycrystalline solid solutions of BiFeO₃ with PbTiO₃, PbZrO₃, and [50PbZrO₃·50PbTiO₃] were determined using the Faraday method. Pure BiFeO₃ has a G-type antiferromagnetic structure. Although the perovskite BiFeO₃ exhibits a sharp peak in the susceptibility at the Néel temperature, it does not possess a spontaneous magnetic moment. The solid solutions investigated possessed a spontaneous magnetic moment throughout the multiple cell rhombohedral region of the BiFeO₃-PbTiO₃-PbZrO₃ ternary phase diagram, which extends from pure BiFeO₃ to …

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 …