Physical Sciences and Mathematics Commons^™

Statistical Time-Dependent Model For The Interstellar Gas, H. Gerola, Menas Kafatos, R. Mccray

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present models for temperature and ionization structure of low, uniform-density (n ~ 0.3 cm^-3) interstellar gas in a galactic disk which is exposed to soft X-rays from supernova outbursts occurring randomly in space and time. The structure was calculated by computing the time record of temperature and ionization at a given point by Monte Carlo simulation. The calculation yields probability distribution functions for ionized fraction x, temperature T, and their various observable moments. These time-dependent models predict a bimodal temperature distribution of the gas with structure in x, T that agrees with various observations. Cold regions in the low-density …

Ua12/2/1 College Heights Herald, Vol. 53, No. 27, Wku Student Affairs

WKU Administration Documents

WKU campus newspaper reporting campus, athletic and Bowling Green, Kentucky news. Articles in this issue:

• Johnston, Scott. English department Reevaluates CLEP
• Caudill, Tom. New Course Offerings Decrease This Semester
• Sen. Edmund Muskie to Speak Tuesday
• Strehl, Mary & Harry Sarles. Far out … WKU Astronomers Are Monitoring Comet for Radio Waves - Kohoutek
• Rice Bowl Bus to Leave at 8p.m
• Scholarships to Be Awarded to ROTC Students
• Research Conference Set – Sigma Xi Society
• Show Recreates Nativity Sky – Hardin Planetarium
• Energy Crisis Hits Others More Severely Than Western
• Skidoo! 15^th Street Hill Bears Watching
• Brizendine, Clint. Free Market …

Proposal: Pioneer Venus Orbiter Mission Magnetic Field Investigation, Edward J. Smith, Leverett Davis Jr., Douglas E. Jones, Bruce T. Tsurutani

Faculty Publications

The magnetic field investigation on the Venus Orbiter Mission must provide sensitive, accurate measurements of the magnetic field at all locations along the spacecraft orbit. In addition to being able to search for and measure any weak global magnetic field that may exist, the magnetometer must have the capability of measuring fields at frequencies high enough to permit a comprehensive study of the bow shock, the region between the shock and the ionopause, the expansion fan and the wake. Accurate measurements outside the interaction region must be made in order to provide necessary information concerning the configuration of the perturbing …

A Photographic Study Of The Infrared Oh Airglow, G. C. Loos

Physics & Astronomy ETDs

OH airglow is due to the rotational-vibrational transitions of the hydroxyl radical. Previous efforts to find the airglow's emission height in the atmosphere are discussed. Photography of the infrared airglow with a fast 35mm camera and Eastman Kodak high speed infrared film is described and a method for triangulating emission heights by two station photography is explained. The techniques for reduction of film data to height measurements and velocity measurements are presented. Observations are reported concerning the frequency of occurrence of bright spots and other features on the OH background and the intensity of the airglow as a function of …

Determination Of (N, 2n) Reaction Isomeric Cross Section For 87rb, 112cd, 138bz, And 186w Using 14 Mev Neutrons, Hsiao-Chueh Kao

Masters Theses & Specialist Projects

The purpose of this investigation was to measure the cross section for each of the reactions 87_{Rb(n, 2n)} 86m_Rb, 112_{Cd(n, 2n)}111m_Cd, 138_{Ba(n, 2n)} 137m_Ba and 186_{W(n, 2n)} 185m_W at 14.7 ± 0.03 MeV incident neutron energy. The incident neutron flux was determined during each irradiation from the activity produced in copper or aluminum disks between which the isotopically enriched sample was sandwiched. The 63_{Cu(n, 2n)}62_Cu and 27_{Al(n, p)}27_Mg reaction cross sections were assumed to be 593 ± 45 mb and 73 ± 5 …

Intensity Correlation Spectroscopy Of Heme Proteins And Motile Microorganisms, Gordon E. Banks

Physics & Astronomy ETDs

The recently developed technique of autocorrelation of intensity fluctuations of Rayleigh (quasi-elastically) scattered light allows measurement of some dynamic properties of particles in solution. The origin of the intensity fluctuations and the form of the correlation spectra for various situations are discussed. The apparatus and methods are described along with methods of data reduction and sources of error. Measurements were made using a Spectra-Physics Model 125 (50mW) He-Ne laser (6328Å) in conjunction with a Saicor 43A 400 channel correlation and probability analyzer. The diffusion coefficient of cyanometmyoglobin was found to be D_{20, w} = (9.47 ± 0.28) x 10 …

Sensor Package For Electrical Sensing Of Plane Coordinates And Method Of Preparing The Same, George S. Hurst, William C. Colwell Jr.

Physics and Astronomy Faculty Patents

A sensor package for ready insertion in properly registered position upon, or for removal from, a cabinet employed in electrical sensing of plane coordinates, is constructed to provide accurate readings when pierced by a small manually operated cursor.

A method for manufacturing the package including the affixing of accurately spaced electrodes on the package, is disclosed.

Dynamic Impulse Calibration Of Sheet Loaded Explosive, William James Johnson

Physics & Astronomy ETDs

In the past, experimenters have used Sheet Loaded Explosive (SLE) to simulate the damage caused by x-rays to an ICBM as the result of a nuclear burst from an ABM. One of the attractive features of SLE is that it can also provide high impul3e levels for structural damage studies. Previous measurements of the usual shock parameters such as peak overpressure, ietonation velocity, and shock front definition with short time interval pressure transducers were not suitable for total impulse measurements. The High Explosive Impulse Responder (HEIR) was developed to fill the need for a simple, reliable and economical total impulse …

Giant Loops As Fossil Stromgren Spheres: Their Radio And X-Ray Emission, Menas Kafatos, P. Morrison

Mathematics, Physics, and Computer Science Faculty Articles and Research

The loops are examined as radio and soft X-ray sources under the assumption that they are objects related to the Gum Nebula but much older than it. The loop diameters are likely on the scale of 100 pc or more, as reported recently. This is naturally understood with the fossil Stromgen sphere model. Further progress in understanding the origin of the loops depends on the resolution of certain observational issues.

Time-Dependent Radiative Cooling Of A Hot Low-Density Cosmic Gas, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Detailed calculations are presented for the radiative cooling of a hot (10^4 K ≤ T ≤ 10^6 K) interstellar gas. Below 10^6 K such a gas is not in ionization equilibrium because it is cooling faster than it is recombining. The gas is more ionized at a particular temperature and emits harder radiation than a gas in equilibrium at the same temperature. Optical forbidden lines, particularly the [0 II], [0 III] lines, are much stronger than the hydrogen Balmer lines. Hydrogen lines, if observable, would show a Balmer decrement not very different from that of a radiatively excited nebula. Results …

Effects Of Pressure On The Rotational Phase Transitions And Dielectric Properties Of Solid Cyclopentanol, David Nason Glidden

Physics & Astronomy ETDs

The dielectric constant and loss for solid cyclopentanol have been measured at hydrostatic pressures up to 2.5 Kbar for frequencies of 1 KHz to 5 MHz from 258 °K to 200 °K. Activation parameters have been calculated from the experimental data. In addition, activation parameters have also been calcuated from a fluctuation-barrier model for dipole reorientation and compare favorably with the experimental quantities. The dielectric constant shows that the phase transition from form I, with sperically symetric orientational freedom, to form II, with restricted orientational freedom, is readily brought about at these pressures. This phase transition was elucidated by an …

First Measurements Of Earth Albedo Neutrons In Space, James R. Place

Physics & Astronomy ETDs

NASA satellite OSO-6 carried as part of its payload a proton recoil telescope capable of detecting neutrons between 40 and 200 MeV with directional discrimination. Sixteen months of data from this instrument were analyzed with a view to determining properties of the earth albedo neutron flux above the atmosphere.

The variation of albedo neutron flux with geomagnetic latitude was found to be 1:4 between 0° and 40°. The angular distribution shows that about 40% fewer neutrons come upward from directly beneath the satellite compared to the number coming from a direction tangential to the top of the atmosphere. These results …

One-Dimensional Three-Body Scattering Problem Used As A Testing Ground For The K-Matrix Method For Scattering Reactions Of Complex Systems, D. Rodjak, William Tobocman, Gaurav K. Tandon

Aerospace, Physics, and Space Science Faculty Publications

The scattering reactions of three equal-mass particles constrained to move in a straight line and interacting with each other via zero-range potentials have been analyzed on the basis of the extended R-matrix theory. The simplicity of the model facilitates an exposition of the complexities that result from the existence of rearrangement channels and from the possibility for breakup into three-body channels. The conventional expressions for the K matrix and the T matrix are derived on a rigorous basis. A practical method for approximating the continuum of three-body breakup channels by a discrete set is used to carry out a distorted-wave …

Light Scattering From Mammalian Cells., Albert Brunsting

Physics & Astronomy ETDs

Light scattering intensity functions for concentrically coated spheres (core diameter 7 mu and total sphere diameter 10 mu, approximately) have been computed. The coated spheres model many types of nearly spherical mammalian cells whose nuclei have a low relative refractive index (~1.05) and cytoplasm with a slightly lower relative refractive index (~1.03). Studies are made on the relationships between the scattering coefficients for nonadsorbing, spherically symmetric scatterers. The physical origin of these coefficients is examined for absorbing scatterers. Diffraction accounts for most of the light scattered in the forwards lobe, whereas at larger angles the coated sphere scattering patterns are …

X-Ray Diffraction Studies On Liquids At Very High Pressures Along The Melting Curve Ii. Sodium, Keith H. Brown, J. Dean Barnett

Faculty Publications

Coherent x-ray diffraction patterns for liquid Na have been extracted from measured patterns at 0.5, 7.5, 17, and 43 kbar along the melting curve. The experimentally determined liquid structure factor and resulting radial distribution function are given at each pressure. The position of the principal x-ray intensity peak is reproducible to within 0.5% and shows shifts of the order of 12%. The resulting nearest neighbor distance in the radial distribution function also shifts 12% but is reproducible only to approximately 2%. The distribution functions obtained at points along the melting curve suggest a simple dimensional compression or scaling; however, a …

X-Ray Diffraction Studies On Liquids At Very High Pressures Along The Melting Curve. I. Methods And Techniques, Keith H. Brown, J. Dean Barnett

Faculty Publications

A technique using the tetrahedral anvil high-pressure x-ray system has been developed to extract coherent x-ray intensity patterns of liquids near melting from measured scattering curves in the presence of high-background counts. Radial distribution functions for liquids along the melting curve to pressures of at least 50 kbar can be obtained. At each pressure scattering curves are recorded for the liquid and solid on opposite sides of the melting curve and a subtraction is made to eliminate background and incoherent scattering. Theoretical estimates of the thermal diffuse scattering from the solid are added to the appropriately corrected difference patterns to …

X-Ray Irradiation Apparatus In Which An X-Ray Source Is Energized Upon The Recording Of Irradiation Dosage Data, George S. Hurst, Norbert Thennard, Karl A. Schneider

Physics and Astronomy Faculty Patents

Apparatus for use in examining or treating patients with X-radiation or the like requires the making of a permanent record of the radiation applied. The operation of the radiation source is controlled in dependence upon the making of the record and the to radiation, or dose exposure is limited to a predetermined amount. A method is disclosed for safeguarding the patient and for producing a tangible record of the dose to which the patient is subjected.

Development Of The Oso-6 High-Energy Neutron Detector And Correlation Of Measured Solar Neutron Fluxes To Solar Flares, Frederick Young

Physics & Astronomy ETDs

In an attempt to understand certain of the high energy processes that occur in the solar and terrestrial atmospheres and the interplanetary medium a detector of 20 to 160 MeV neutrons had been designed and constructed for inclusion in the NASA Orbiting Solar Observatory, Satellite OSO-G, which was launched into a near circular orbit at approximately 500 km altitude in August 1969. Both the angle of incidence and the energy of the neutron are determined by a telescopic arrangement of four scintillation plastic counters (Pilot B; hydrogen to carbon ratio 1:1) which generates proton recoils and provides pulse heights for …

Β-Delayed Proton Decay Of 9c, David D. Allred, John E. Esterl, J. C. Hardy, R. G. Sextro, Joseph Cerny

Faculty Publications

The delayed-proton spectrum following the β decay of 9C (t1/2=126.5±1.0 msec) was found to consist primarily of a continuum extending from 13 to 1.5 MeV, the latter being the lowest energy observed. In addition to the previously observed peaks at 9.28 and 12.30 MeV (C.M.), possible peaks between 3 and 7 MeV have been tentatively identified.

Electrical Sensor Of Plane Coordinates, George S. Hurst, James E. Parks

Physics and Astronomy Faculty Patents

An inexpensive electrical sensor of plane coordinates employs juxtaposed sheets of conducting material having electrical equipotential lines extending across each sheet and arranged normal to each other. A probe upon touching each sheet at a selected intersection of the equipotential lines causes separate signals to be applied to one or more conventional information-indicating units.

Cellular Absorbed Dose Spectrometer (Cads) Data Reduction And Analysis., John T. Cervini

Physics & Astronomy ETDs

A detailed description of a space qualified linear energy transfer (LET) spectrometer is presented. The Cellular Absorbed Dose Spectrometer (CADS) is a prototype instrument which was launched on March 17, 1969 into an elliptical orbit. Its purpose was to obtain the first successful LET measurements in space; and, thereby provide additional data to assess the biological hazards of the near earth space environment, especially during periods of in­creased solar activity.

The physical processes that take place in the CADS in­strument are discussed, and a definition of linear energy transfer is given, as well as its relation to dE/dx. The performance …

Interferometric Studies Of Interstellar Calcium Lines, Laurence A. Marschall, L. M. Hobbs

Physics and Astronomy Faculty Publications

Interferometric, photoelectric scans of the interstellar calcium K-lines in the spectra of 65 stars are presented. The scans were obtained with a PEPSIOS spectrometer having a passband with a full half-intensity width of 1.0 kms(-1) or 0.013A. The fivefold improvement in resolution over that used by Adams reveals numerous line components which correspond very well to those of the interstellar sodium lines, apart from frequent differences in relative intensities.

Measurement Of The Average Solar Neutron Flux And Its Correlation With Solar Activity, Pyung Syk Ro

Physics & Astronomy ETDs

Data from the University of New Mexico High Energy Neutron Detector flown on NASA satellite OSO-VI arc analyzed with the aim of detecting neutrons from the sun. The detector is a proton recoil telescope capable of directional discrimination and responsive to neutrons of energies between 20 and 200 MeV with an effective average efficiency for this analysis of 10^-4 and an effective area of 80cm². The detector was located in a wheel compartment of OSO-VI and scanned the sun once per revolution of the wheel at a rate of 30 rpm. The satellite was launched on August …

High-Pressure Equation Of State For Nacl, Kcl, And Cscl, Daniel L. Decker

Faculty Publications

A calculation of the equation of state for NaCl from a Mie-Grüneisen equation was repeated using more accurate values of the zero-pressure compressibility. It was also extended to KCl and CsCl. An analysis of this approach to pressure calibration indicates that it will yield pressures with about the same accuracy as can be presently achieved by experimental measurements above 25 kbar, and thus furnishes a temporary practical pressure scale.

Increasing The Efficiency Of A Surface Ionization Mass Spectrometer, Thomas Curtis Adams

Physics & Astronomy ETDs

An Avco surface ionization mass spectrometer (model 90,000) was installed at the Los Alamos Scientific Laboratory in February, 1968. Since that date this machine has been used as a production instrument for the isotopic analysis of uranium and plutonium samples. During 1969, it was realized that a problem inherent in the ionization mechanism of the instrument was degrading the accuracy of results, and that the number of man-hours expended in reducing data had become excessive. As soon as this situation became apparent, corrective action was initiated to reduce the effect of the ionization problem and to decrease the amount of …

Intensity Ratios For Polarized Refracted Light Near The Critical Angle., Stephanie Layne Moore

Physics & Astronomy ETDs

It was undertaken to investigate the intensity ratio of refracted light polarized parallel and perpendicular to the plane of incidence. The primary object of the experiment was to obtain this ratio for light incident at very nearly the critical angle on a water-air interface, the light having first passed through the water. A laser was used to produce the light beam and the experimental results were compared with the theory propounded by Fresnel for infinite plane waves and elsewhere asserted to hold for bound plane waves. As this theory predicted a ratio of the square of the refractive index (n) …

Dielectric And Phase Behavior In Solid Cyclopentanol., Stephen John Dalich

Physics & Astronomy ETDs

The dielectric and phase properties of cyclopenthanol have been investigated using dielectric constant measurements and visual observations. As a result of these studies a model has been constructed which accounts for the observed dielectric and phase behavior in solid cyclopentanol.

From the dielectric studies three distinct solid forms have been identified in a region from the melting point at -17.5 C to -80 C. Two of these, forms I and II, are rotational phases, the third is nonrotational. The studies have concentrated on the two rotational forms and the transition between them.

The previously reported dielectric anomalies have been investigated …

Linear Pulsation Analysis Of Cluster Cepheid Variables, Charles E. Needham

Physics & Astronomy ETDs

Models for thirteen classical Cepheids found in galactic clusters or associations are analyzed. The models are calculated using the most recently published photometric data and theoretical evolutionary tracks. The linearized equations of mass, momentum and energy conservation are solved subject to an infinitesimal radial perturbation of each equilibrium model. The equations are first solved in the adiabatic approximation. This solution is then used as the initial value for the iterative solution of the non-adiabatic equations. The linearized analysis provides information on pulsation periods of fundamental and harmonic modes, stability against pulsations and phase differences between various physical parameters, such as …

Lamb-Mössbauer Factor Of Sodium Ferrocyanide, Daniel L. Decker, L. E. Lortz

Faculty Publications

Using a set of commercially prepared sodium ferrocyanide absorbers enriched to 91.2% Fe57 the Lamb-Mössbauer factor was measured to be 0.28±0.03. The thickness of Fe57 for these absorbers was measured using x-ray absorption techniques and was found to be considerably smaller than that advertised by the manufacturer even after correcting for the size of the ferrocyanide particles in the absorbers.

A Vibrational And Rotational Analysis Of Eight Simple Models Of The Hydrogen Molecule In The Ground State., Stuart Fleming Hayes

Physics & Astronomy ETDs

The object of this dissertation was the investigation of the influence on the delta G curve for H2 of polarization, enhancement of charge between the nuclei, and variation of the screening parameter. A better understanding of the influence of these factors could lead to progress in estimating more accurately the dissociation energies of diatomic molecules. Also to be investigated was the correlation between these factors and the vibrational and rotational spectroscopic constants, particularly Bv.

The Heitler-London combination of atomic orbitals (referred to as phi 1) was used in every wave function The atomic orbital 2pz was used in phi 2 …