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Articles 8911 - 8940 of 9199
Full-Text Articles in Physical Sciences and Mathematics
X-Ray Induced Luminescence Of Sapphire And Ruby, Ivan Collier Jr.
X-Ray Induced Luminescence Of Sapphire And Ruby, Ivan Collier Jr.
Masters Theses & Specialist Projects
Over the past decade the luminescence properties of sapphire (∝-AL2O3) and ruby (Al2O3:Cr2O3) have been the subject of many investigations because of their importance in materials technology. Sapphire and ruby are at present used as lasing materials, radiation dosimeters, and as optical windows. In order that these operations may be made more efficient, and that other useful luminescent properties may be systematically explored and developed, much attention has been given to understanding the luminescent mechanisms from the standpoint of the physics of the solid state. However, mechanisms have …
-Ray Induced Luminescence Of Ruby, Wayne Cooke
-Ray Induced Luminescence Of Ruby, Wayne Cooke
Masters Theses & Specialist Projects
Since the advent of the laser there has appeared a multitude of scientific papers describing the various parameters that would affect the lasing action of the ruby laser. Many investigations have been carried out to determine the efficiency of the R-line fluorescence in ruby: however very little work has been done concerning the X-ray-induced luminescence of ruby.
Certainly the applications to laser technology would be of sufficient importance to merit a study of ruby under continuous irradiation, although this was not the main stimulus that motivated this investigation. The original program of study was undertaken to determine if there existed …
Propagation Of Ultrasound In Plastic Crystals, Carl E. Scheie
Propagation Of Ultrasound In Plastic Crystals, Carl E. Scheie
Physics & Astronomy ETDs
The study of the organic solid state, and in particular of plastic crystals, is a relatively new branch of physics (1,2). Timmermans first surmised the existence of these solids from the anomalous values of the entropies of fusion. The solids possess many of the characteristics of liquids. They are easily deformed by pressure and they show dielectric properties that can be described on the basis of rotation of the molecules in their lattice positions. Still they have a definite crystal structure. Thus, even though the molecules are not symmetric, they appear to be to some degree because of the rotation. …
Ua11/2 Apollo Model Displayed At Western, Wku Public Affairs
Ua11/2 Apollo Model Displayed At Western, Wku Public Affairs
WKU Archives Records
Press release regarding Apollo 11 command module model exhibit.
Ua11/2 Plantarium Director Warns Of Eye Damages During Saturday Eclipse, Wku Public Affairs
Ua11/2 Plantarium Director Warns Of Eye Damages During Saturday Eclipse, Wku Public Affairs
WKU Archives Records
WKU press release entitled: Planetarium Director Warns of Eye Damages During Saturday Eclipse.
Rayleigh Hysteresis Shape: Its Relationship To Displacement Distance Of A Single Domain Wall In 50% Ni–Fe, R. C. Woodbury, M. R. Hunt
Rayleigh Hysteresis Shape: Its Relationship To Displacement Distance Of A Single Domain Wall In 50% Ni–Fe, R. C. Woodbury, M. R. Hunt
Faculty Publications
The need to measure the displacement distance of domain walls from equilibrium for very weak alternating fields (H ≪ coercive force) in bulk magnetic material has prompted a study of the possible use of the opening of the Rayleigh hysteresis loop to indicate the amount of wall displacement. This paper contains (1) a review of the theoretical relationship between hysteresis shape and the displacement distance of a domain wall, based upon defect-energy models of Rodbell and Bean, and Baldwin; and (2) an experimental approach which provides a measure of the wall displacements versus hysteresis shape for 50% Ni–Fe tape. Discrepancies …
Ua11/2 Planetarium Program To Describe The Moon In February Sessions, Wku Public Affairs
Ua11/2 Planetarium Program To Describe The Moon In February Sessions, Wku Public Affairs
WKU Archives Records
Press release entitled: Planetarium Program to Describe the Moon in February Sessions.
Proposed Thermodynamic Pressure Scale For An Absolute High-Pressure Calibration, Daniel L. Decker, J. Dean Barnett
Proposed Thermodynamic Pressure Scale For An Absolute High-Pressure Calibration, Daniel L. Decker, J. Dean Barnett
Faculty Publications
The field of high pressure has developed rapidly over the past few years to a point where relatively sophisticated experiments are being attempted. In many experiments it is no longer sufficient to qualitatively estimate the pressure or to base conclusions on experimental results tied to an empirical pressure parameter. One desires to accurately know the pressure dependence of physical quantities related to a true thermodynamic scale.
Measurement Of Cyclohexane Ultrasonic Velocity Using Photon-Phonon Scattering Interactions, Edward W. Taylor Jr.
Measurement Of Cyclohexane Ultrasonic Velocity Using Photon-Phonon Scattering Interactions, Edward W. Taylor Jr.
Physics & Astronomy ETDs
The construction of a frequency modulated optic cell and its operation for studying the ultrasonic velocities of cyclohexane, acetone and ethyl alcohol as a function of temperature is described. A description of photon-phonon scattering interactions is presented. The appearance of the intensity distribution of the scattered light is treated, and an analysis of the experimental results is included. The special scattering case of Bragg diffraction of coherent light was used for determining the ultrasonic velocities of cyclohexane as a function of temperature. Ramifications of the Raman-Nath and Bragg diffraction effects are discussed. The relationship vT = 1376.78 - 5.25 …
Radar Meteorology, Jerry Thomason
Radar Meteorology, Jerry Thomason
Honors Theses
Radar, an acronym for RAdio Detection And Ranging, has been a great aide to the growth of the knowledge of science, especially for uses in weather research.
The discovery of the nature of radar is thought to have been made by Dr. A. H. Taylor and Leo C. Young of the Naval Research Laboratory when they found that radio waves would bounce back from steel. The military perfected radar for its benefits and gradually improved its technique of usage during the years of World War II. The British had its own version of radar and it is believed that its …
Antimatter, Claudia Morgan Griffin
Antimatter, Claudia Morgan Griffin
Honors Theses
Very little is known about the mysterious world of antimatter. The idea that such particles could exist was not even proposed until forty years ago. Perhaps the story of the discovery of antimatter began when scientists were trying to unify the Theory of Relativity and the Theory of Quanta. The trouble was that the quantities in the classical wave equation are in the second derivatives. In Schrodinger's wave equation of the Quantum Theory, x, y, and z are second derivatives, but i is a first derivative.
Following Einstein's basic ideas, H. Minkowski proposed the concept of a four-dimensional time-space continuum …
The Monte Carlo Method Applied To An Estimation Of Delayed Neutron Response, Garland David Turner
The Monte Carlo Method Applied To An Estimation Of Delayed Neutron Response, Garland David Turner
Physics & Astronomy ETDs
An experimental program has been undertaken at Los Alamos Scientific Laboratory to study delayed neutron effects. As a part of this program, experiments were conducted with thin disks of various fissionable materials to measure the delayed neutron response to a pulse of high-energy neutrons. In support of the experiments, calculations were made with a computer program which solves the Boltzmann transport equation by finite difference methods. Difficulties with the calculations led to an analysis showing that correct treatment of neutrons moving parallel to the faces of the disk was vital to the success of the calculation. As an extension of …
A Study Of The Sidereal Diurnal Variations Of Cosmic Rays Underground., Albert Brunsting
A Study Of The Sidereal Diurnal Variations Of Cosmic Rays Underground., Albert Brunsting
Physics & Astronomy ETDs
The sidereal diurnal variation of cosmic rays has been measured using underground (40 m.w.e.) meson telescopes located near Albuquerque, New Mexico (35.20°N, 106.41°w) and at Chacaltaya, Bolivia (16.31°s, 68.15°w). Each ofthe two locations has telescopes which scan the vertical and four inclined directions.
Two and three complete years were used for the telescopes at the Bolivia and New Mexico locations respectively. The average solar diurnal variations were calculated for each telescope for each month. Based on these monthly averages, the sidereal diurnal variations were computed. A correction was made in the analysis for any yearly modulation of the solar diunal …
A Shock Tube Study Of Recombination In The Lean Hydrogen-Oxygen Reaction Based On The Infrared Emission From Water Vapor, Larry S. Blair
A Shock Tube Study Of Recombination In The Lean Hydrogen-Oxygen Reaction Based On The Infrared Emission From Water Vapor, Larry S. Blair
Physics & Astronomy ETDs
ABSTRACT
Recombination in the hydrogen-oxygen reaction has been studied by monitoring the growth of infrared emission at 2.7 microns from water vapor as it is formed behind incident shock waves. Experiments were carried out in gas mixtures with hydrogen-to-oxygen ratios between 1.0 and 0.33 and temperatures between 1435° and 1868°K. Reactants were diluted with 92-98% argon. The validity of the transparent gas approximation (emission intensity proportional to (H20]) and the relationship between emission intensity and temperature were established by calibration experiments in which mixtures of water vapor and argon were shock-heated to temperatures between 1328° and 1982°K. Analysis of H20-emission …
Meteorological Effects On Cosmic Rays At Albuquerque, New Mexico., David Nason Glidden
Meteorological Effects On Cosmic Rays At Albuquerque, New Mexico., David Nason Glidden
Physics & Astronomy ETDs
Ground-based observations of cosmic-ray intensity have the disadvantage of being more sensitive to variations of atmospheric temperature and pressure than to the more interesting variations in the primary cosmic radiation. It is, therefore, imperative to correct the recorded cosmic-ray intensity for variations of atmospheric origin before studies can be made of the smaller variations of the primary cosmic ray intensity.
In this thesis an attempt has been made to remove the variations of atmospheric origin from the cosmic-ray intensity recorded simultaneously by a neutron monitor and a meson telescope located at Albuquerque, New Mexico. It was found that the neutron …
Introduction To Astrophysics And Study Of Cosmic-Ray Collisions And Scanning, David L. C. Lau
Introduction To Astrophysics And Study Of Cosmic-Ray Collisions And Scanning, David L. C. Lau
Honors Theses
The discovery of tremendous amounts of energy from the Atomic Explosion (ex: first Atomic Bomb on Hiroshima) was not something new. For billions of years, atoms have been splitting with the release of such energy whenever stars are shining. We know that the atomic energy is being released from the sun and stars, and that this process has been going on for unthinkable years. However, the sun's atomic energy has been under control constantly, and its release of radiation (dynamic force) has supplied the constant supply of light and heat best suited for the well-being of mankind.
There are times, …
Theoretical Analysis Of The Vibrations And Rotations Of The B¹[Sigma][Mu] State Of The Hydrogen Molecule, Sandra Zink Moody
Theoretical Analysis Of The Vibrations And Rotations Of The B¹[Sigma][Mu] State Of The Hydrogen Molecule, Sandra Zink Moody
Physics & Astronomy ETDs
Theoretical calculations of the rotational-vibrational constants of the B1Σ+u state of H2 were made using the Dunham analysis and by fitting equations to energy eigenvalues. The potential energy function for the nuclei used in the calculations was computed by W. Kolos and L. Wolniewicz using the variational technique. The power series used in the Dunham analysis made use of Stirling's central difference interpolation polynomial. The equilibrium separation Re found from the Born-Oppenheimer potential is 2. 429165 atomic units, differing from the Kolos-Wolniewicz value of 2.4288. Adiabatic corrections were taken into account through a …
New Solutions Of The Einstein-Maxwell Equations From Old, B. Kent Harrison
New Solutions Of The Einstein-Maxwell Equations From Old, B. Kent Harrison
Faculty Publications
Methods are discussed with which one may derive theorems which allow one to generate new solutions of the Einstein-Maxwell equations from old ones. The old solutions used to generate new ones must admit at least one nonnull Killing vector and may be required to satisfy other conditions, depending on the theorem derived. Examples of derivable theorems are shown; these theorems are used in turn to show how generation of new solutions is accomplished. Examples of the latter are shown, such as generation of Brill or electrified NUT space from the Schwarzschild solution, generation of a new twisted Melvin universe from …
Response Prediction For The Oso-G Satellite Solar Neutron Instrument By Matrix Methods., John Coalmer Conklin
Response Prediction For The Oso-G Satellite Solar Neutron Instrument By Matrix Methods., John Coalmer Conklin
Physics & Astronomy ETDs
Properties of the University of New Mexico’s solar neutron instrument for use on the NASA 0S0-C satellite were investigated. A sensor model was developed by use of two computer codes. First, the total efficiency of the converters was calculated by a simulation code with a resulting total efficiency at 100 Mev of approximately two per cent of which four-fifths was carbon recoil contribution.
Second, geometry properties of the instrument were provided by a Monte Carlo program, with maximum geometry efficiency equaling about fourteen per cent. These were combined to give a total response profile for the instrument which was expressed …
The Motion Of A Charged Particle In The Field Of A Magnetic Dipole, E. Royce Fletcher
The Motion Of A Charged Particle In The Field Of A Magnetic Dipole, E. Royce Fletcher
Physics & Astronomy ETDs
The principal difficulties encountered in attempting to solve the general problem of the motion of a non-relativistic, non-radiating charged particle in a magnetic field which varies position and time, are associated with the induced electric field. That is to say, the time variation of the magnetic field produces an electric field which also acts on the particle. Both these fields must be known as functions of time and position if the equations of motion are to be determined exactly.
The Spectroscopic Constants Of The Ground Electronic State Of Hydrogen Molecular Ion, Bertle Daniel Hansen
The Spectroscopic Constants Of The Ground Electronic State Of Hydrogen Molecular Ion, Bertle Daniel Hansen
Physics & Astronomy ETDs
ABSTRACT
An accurate theoretical determination of certain vibration rotation properties of the hydrogen molecular ion is made. Two different methods of analysis are used in the determination of these properties. First, an energy equation for diatomic molecules is
fitted directly to theoretical vibration and rotation eigenenergies of the ground electronic state of H+2 calculated by J.M. Peek. These eigenenergies include adiabatic corrections determined by w.Kolos. Second, a fixed-nucleus potential for the ground electronic state of H+2, calculated by J. M. Peek which did not include adiabatic corrections, is expanded in a power series in the neighborhood of the equilibrium internuclear …
Pressure And Temperature Dependence Of The Acoustic Velocities In Polymethylmethacrylate, James Russell Asay
Pressure And Temperature Dependence Of The Acoustic Velocities In Polymethylmethacrylate, James Russell Asay
Physics & Astronomy ETDs
The acoustic velocities in polymethylmethacrylate have been measured with an ultrasonic pulse echo technique as functions of frequency, temperature and pressure. At atmospheric pressure, data on the velocities and attenuation coefficients were obtained over the range of temperature from 22°c to 75°c and for the frequency range of 6 to 30 MHz. At the temperatures of 25, 40, 55 and 75°c, the pressure dependence of the longitudinal and shear velocity was obtained to 150,000 psi at a frequency of 6 MHz. From the frequency measurements of the velocities, the complex elastic moduli in polyrnethylmethacrylate were calculated at room temperature. The …
Dose And Depth Dose Measurements On The Sixth Gemini Flight, A Comparison With The Gemini-4 Radiation Measurements, Marion F. Schneider
Dose And Depth Dose Measurements On The Sixth Gemini Flight, A Comparison With The Gemini-4 Radiation Measurements, Marion F. Schneider
Physics & Astronomy ETDs
Two tissue-equivalent ionization chambers were flown behind 0.4 gram/cm.2 and 2.5 grams/cm.2 of shielding inside the Gemini-6 spacecraft. The instruments measured the radiation levels resulting from primary cosmic radiation and the trapped particle environment of the earth's Van Allen belts. Each sensor was constructed from a special tissue-equivalent plastic with radiation cross sections that closely match standard muscle tissue for the many complex types and energies of radiation encountered in space. The design of the sensor and logarithmic electrometer preamplifier are described in detail. The calibration and directional sensitivity of the sensors with cobalt-60 and cesium-137 gamma radiation …
"Planetary Exploration (Lecture Two)", Carl Sagan
"Planetary Exploration (Lecture Two)", Carl Sagan
Special Collections: Oregon Public Speakers
Requested by: "Standing order from Science" "Planetary Exploration"
"Planetary Exploration (Lecture One)", Carl Sagan
"Planetary Exploration (Lecture One)", Carl Sagan
Special Collections: Oregon Public Speakers
No abstract provided.
The Red Leak And Its Effect In Ultraviolet Photometry., Jeffrey David Colvin
The Red Leak And Its Effect In Ultraviolet Photometry., Jeffrey David Colvin
Physics & Astronomy ETDs
The red leak in the red and of the ultraviolet filter (Corning #9863) of the standard UBV photometric system is investigated. Astronomical photometry is discussed in general, and UBV photometry in particular. The photometric system used in this work is also discussed, including telescope, phototube, filters, and amplifier. The standard filters of the UBV system are used, but the standard phototube of this system is not used. An analytic representation of the red leak magnitude correction is developed.
Sixty-five measurements were made for a wide variety of stars from spectral class B3 to spectral class M2. The red leak correction …
A Method For Measuring Magnetization To High Pressures, C. R. Johansen, Mark H. Nelson, J. H. Gardner
A Method For Measuring Magnetization To High Pressures, C. R. Johansen, Mark H. Nelson, J. H. Gardner
Faculty Publications
A partially successful attempt has been made to measure the magnetic moment per unit volume of ferromagnetic materials as a function of pressure to the 100-kbar region. The apparatus, an early version of which has been described previously, consists basically of two opposed Bridgman flat anvils of alumina. One anvil also acts as a dielectric-filled microwave resonant cavity for an x-band spectrometer, allowing electron spin resonance studies to be made to high pressure. The sample to be studied is placed in contact with the anvil-cavity and covered with a pressure-transmitting medium which in turn is encircled by a flat pyrophyllite …
Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner
Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner
Faculty Publications
The variation in the electron paramagnetic resonance (EPR) spectrum of ruby as a function of pressure has been observed to beyond 70 kbar for a magnetic field orientation parallel to the crystalline c axis. The data can be interpreted in terms of the usual spin Hamiltonian, where the spectroscopic splitting factor g|| has the same value as at ambient pressures, but where the zero-field splitting deltaincreases in a linear fashion from 0.38 to 0.43 cm. The experimental apparatus has been described previously, although important improvements in the pressure seal and in the pressure calibration have been made and are described …
Rocket Probe Measurement Of Electron Energy Spectra In The Earth's Radiation Belts, Donald Stuart Robb
Rocket Probe Measurement Of Electron Energy Spectra In The Earth's Radiation Belts, Donald Stuart Robb
Physics & Astronomy ETDs
No abstract provided.
An Introduction To The Fundamentals Of Radiation Transport Theory., William A. Proctor
An Introduction To The Fundamentals Of Radiation Transport Theory., William A. Proctor
Physics & Astronomy ETDs
I first became interested in radiation transport theory when, in August 1966, I was given primary responsibility for a large computer program which serves as a tool for solving high temperature, time dependent, radiation-hydrodynamics problems. Inquiries as to where to start learning about this subject invariably resulted in my being directed to the two books by Chandrasekhar (1957 and 1960) and the book by Kourganoff (1963). From the beginning of my study of these expositions, I found it rather curious that a theory which treated the radiation field as continuously distributed in space was formulated in a manner which appeared …