Physical Sciences and Mathematics Commons^™

Neutron-Proton Elastic Scattering At 790 Mev, Roger Daniel Carlini

Physics & Astronomy ETDs

The forward n-p differential cross-section is measured at 790 Mev from 9.5 to 60. degrees in the center of mass. The systematic errors are less than 4.0%. The differential cross-section is parameterized by the function dσ/dΩ = A e^bt, where t is the momentum transfer between the incoming and outgoing neutrons in (GeV/C)², and A and b are constants having the values A= 9.757±.069, b= 5.052±.045. With 36 data points the x² is 55. The magnitude of the ratio of the real to imaginary part of the forward scattering amplitude is found to be .3501±.14.

Astronomy And The Bible: Joshua's Long Day, Joel W. Block

Physics Faculty Publications

The Bible has served as a multipurpose text for thousands of years. However, the Bible has been ignored in the area of astronomy. Several teaching points can be demonstrated using the Bible stories and modern astronomical principles.

Convection In Pulsating Stars, Michael John Robert Costello

Physics & Astronomy ETDs

Stellar models using mixing length convection in a linear calculation show a red edge to the instability strip. The models are of a 6 solar mass, 1 x 10 ergs/sec luminos­ity, King 4A composition, cepheid variable star, for various values of effective temperature, Te, and mixing length parameter, a. Results are obtained with an assumed instantaneous adjustment of the convective flux to changes in the local stellar conditions. Calculations of the convective time de­lay show it to be small compared to the period, under the assumption that the convective time delay is due solely to the inertia of convective bubbles. …

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson

Faculty Publications

Depth profiles for hydrogen in amorphous silicon have been determined by the use of resonant nuclear reactions [1H(15N,αγ)12C and 1H(19F,αγ)16O] and by secondary ion mass spectroscopy (SIMS). Independent calibration procedures were used for the two techniques. Measurements were made on the same amorphous silicon film to provide a direct comparison of the two hydrogen analysis techniques. The hydrogen concentration in the bulk of the film was determined to be about 9 at % H. The SIMS results agree with the resonant nuclear reaction results to within 10%, which demonstrates that quantitative hydrogen depth profiles can be obtained by SIMS analysis …

Heights Of Formation For Certain Solar Spectral Lines, Erik J. Schwendeman

Physics & Astronomy ETDs

Heights of formation are calculated for several of the solar spectral lines studied by the National Aeronautics and Space Administration - Goddard Space Flight Center (NASA-GSFC) New Mexico Solar Station at Sacramento Peak Observatory. These lines are Ca II H, K, 8498 Å and 8542 Å, MgI b₁, NaI D₁ and D₂ and Sil 4103 Å. I calculate the heights of formation for each of these lines along with upper and lower confidence limits representing the height region where 90% of the total intensity of the line is formed in the solar photosphere and chromosphere. The …

A Covariant Approach To Wave Equations In General Relativity, Alan L. Dudley

Physics & Astronomy ETDs

A formalism for the manipulation of tensors in both real and complex spacetimes is introduced, which utilizes the irreducible representations of the Lorentz group to substantially simplify certain general relativistic calculations. The notation is completely covariant and is most effective for massless field calculations. Results emerge which eliminate the majority of the algebraic burden of the traditional Newman­Penrose formalism and, simultaneously, allow the reader to understand both the physical and geometrical meanings of each step of the derivations. The technique developed is well suited for perturbation analyses. Consequently, the perturbed wave equations for massless fields are examined. The notation has …

"Address To Faculty And Students", Timothy Francis Leary

Special Collections: Oregon Public Speakers

Dr. Leary's first speech at Portland State University was ten years prior to this date. The recording of his 1967 talk was stolen from the Portland State library.

Plasma Sheath Analysis By Computer Simulation, Leo J. Rahal

Physics & Astronomy ETDs

The time development of a fully ionized, dense two-component plasma is investigated through the use of a one-dimensional particle simulation code. The plasma is initially composed of two distinct regions. One region is a uniform plasma in which electrons and ions are at the sane temperature and have no electric fields due to charge separ­ation. The other region contains a charge separation of electrons and ions resulting in an electric field. There also exists an electron current which produces a confining magnetic field. This is the sheath region between the neutral plasma and the confining magnetic field. The simulation occurs …

Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert

Physics & Astronomy ETDs

In Chapter 1, I outline the methods of making ground-based infrared observations. I concentrate on the observational procedures rather than the instrumental design. Near-infrared observations of S 156A, _S 158A, S 159A, S 162A₁, S 228, and G 45. 5 + 0 .1 (#2) made with a beam size of ̴1 are used to estimate the total near infrared flux. After correcting for the line of sight extinction the near infrared luminosities are greater than the Lyman-α luminosities inferred from radio observations. A strong double peaked infrared source was discovered near the region of G 25.3-0.1. The infrared …

Theoretical Studies Of Nucleic Acid Sugar Ring Analogs, Ali-Reza Hashemi-Attar

Physics & Astronomy ETDs

Extended Hueckel theory (EHT) was used to study analogs of sugar rings in nucleic acid monomers. The energy gradient in a variable metric algorithm was used to find the potential energy along the pseudorotation path. Use of the energy gradient made it possible to permit 34 degrees of freedom in a molecule. Seven molecules and their isomers were studied. These were: 3-hydroxy2-methyl tetrahydrofuran, 2-ami no-4-hydroxytetrahydrofiJran, 5-ami no3-hydroxy-2-methyltetrahydrofuran (deoxyribonucleic acid analog), 3,4-dihydroxy-2-methyltetrahydrofuran, 2-amino-3,4-dihydroxytetrahydrofuran, 2-amino-5-methyltetrahydrofuran, and 2-amino-3,4-dihydroxy-5-methyltetrahydrofuran (ribonucleic acid analog).

It was shown that the difference in sum of total overlap populations (TOP) for all pairs of atoms between two related conformations …

El Viento De Las Estrellas, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

¿Dónde Está El Límite Del Universo?, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

The Nitrogen Dayglow On Mars, Jane L. Fox, Alexander Dalgarno, E. R. Constantinides, G. A. Victor

Physics Faculty Publications

The ultraviolet dayglow spectrum arising from emission of N₂ in the Mars atmosphere is predicted. The intensities are such that a high-resolution spectrum should readily reveal the presence of N₂ at the abundances suggested by the Viking experiments.

Solar Magnetoatmospheric Waves-A Simplified Mathematical Treatment, John A. Adam

Mathematics & Statistics Faculty Publications

The inhomogeneous wave equation for a special class of magnetoatmospheric waves is formally solved, and the principle of stationary phase used to provide information on the group velocity properties of such waves. General results are presented concerning the associated mechanical energy flux. The basic problem considered is relevant to waves initiated by sudden events in the solar atmosphere.

Geophysical Institute Annual Report 1976-77, University Of Alaska Fairbanks. Geophysical Institute

GI Reports

The 1976–77 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.

Computer Model Of A Fast Toroidal Plasma Compression, With Application To The Topolotron, H. Mark Nelson, Keith H. Brown, Charles A. Hart

Faculty Publications

The method is developed for a comuputer sequence which models a fast toroidal theta or screw pinch for a highly conducting axially symmetric plasma. The computer sequence takes into account the self-inductances of the plasma and the external conductors which drive the compression as well as the mutual inductance which electromagnetically couples the two. The computer sequence is divided into three phases: a snowplow compression phase, an adiabatic compression phase, and a crowbarred circuit phase. The computer sequence is applied to a topolotron and an example is given of a magnetohydrodynamic equilibrium geometry for which the plasma surface possesses an …

Behavior Of A Manganin Coil At Elevated Temperatures And Pressures, Jonathan D. Weiss, Daniel L. Decker, H. B. Vanfleet

Faculty Publications

We have determined the temperature dependence in the first-order pressure coefficient of a manganin coil to be dBetaB/dT= (4.2±0.8) ×10^-7 (kbar degrees C)^-1 in the equation R (T,P) =R (T,0)(1+BetaP+GammaP2), where R (T,P) is the coil resistance at temperature T and pressure P. The measurements were performed by simultaneously measuring the coil resistance and temperature at the transitions of mercury and bismuth, which were observed by differential thermal analysis.

Geophysical Institute Annual Report 1975-76, Geophysical Institute

GI Reports

The 1975-76 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.

Neutron Spectra At Zero Degrees From Proton Bombardment Of Light Nuclei At Medium Energies, Constantine George Cassapakis

Physics & Astronomy ETDs

The neutron-momentum spectra at 0° resulting from proton bombardment of 9Be, 12C, and 27Al at Tp=633MeV, and those of 12C and 27Al at Tp=786 MeV, have been measured at the LAMPF (Los Alamos Meson Physics Facility)-Nucleon Physics Laboratory.

The measurements utilized the recently developed single arm, multiwire proportional counter, recoil-proton, magnetic spectrometer. I

dentification of the recoil charged particles was achieved through momentum analysis and simultaneous time­of-flight determination for each particle constituting a valid event.

The momentum and energy resolutions achieved are about 1% and 1.4%, respectively, at the incident proton energies considered.

The spectra for 9Be and 27Al exhibit …

Ultraviolet Radiation Effects On Rotifers, Syed Asim Hussain

Masters Theses & Specialist Projects

The purpose of this investigation was to study ultraviolet radiation effects on rotifers. The rotifer studied was Philodina acuticornis odiosa Milne. Isolation cultures were used to grow the rotifers individually in separate U-plate depressions. The source of ultraviolet radiation consisted of four mercury germicidal lamps used in combination to deliver a uniform flux of 315 uW/cm² over the sample. Five groups of rotifers, one control and four experimental groups of 96 each, were used. The rotifers used were 2-10 hours of age at the beginning of the experiment. The experimental groups were exposed to uv radiation for 3 minutes, …

"The Search For Extra-Terrestrial Life", Donald L. Devincenzi

Special Collections: Oregon Public Speakers

No abstract provided.

Sensitivity Of A Gas Filter Correlation Instrument To Variations In Atmospheric Profile And Earth Surface Temperatures, Joseph C. Casas

Physics Theses & Dissertations

The Gas Filter Correlation Radiometer Analyzer (GFCR), in application to the remote sensing of trace gases in the atmosphere, is potentially limited by the sensitivity of the measured upwelling thermal radiation to surface temperature and atmospheric temperature conditions. This study has been carried out to examine the principles of operation of the GFCR Analyzer and to obtain quantitative estimates of the errors produced in GFCR Analyzer measurements of CO (4.6μ), S02 (8.6μ), NH3 (11.0μ), and CH4 (8.1μ) resulting from uncertainties in the atmospheric temperature profile and ground temperature.

A simple mathematical prototype GFCR Analyzer was assumed. A line-by-line atmospheric radiative …

The Determination Of Double Mode Variable Star Periods, Arne A. Henden

Physics & Astronomy ETDs

ABSTRACT

The problem of determining the periods of objects oscillating in one or more modes is discussed. Although the methods described are applicable to many different kinds of objects and observations, the discussion has been limited to double mode Cepheid stars.

Two methods of solution are followed in detail. An autocorrela­tion technique based on the scatter of points in an amplitude-phase plane is used for most cases. A means of calculating smoothed mean curves is discussed. A Fourier transform method is presented for closely spaced data points, with prewhitening included for accurate secondary period and amplitude determinations.

Three test problems …

A Satellite Study Of The High Energy Proton Environment Under The Radiation Belt, Kailash Chandra Dhingra

Physics & Astronomy ETDs

Proton data outside of the South Atlantic Radiation anomaly (in the regions where h_min < 0) from the University of New Mexico High Energy Neutron and Proton Detector aboard OSO-6 satellite were analyzed in the present work. The detector was useful in the energy range from 75-145 Mev and the data were obtained during the period from August 1969 to January 1971. The altitude of the satellite varied from about 480 Km to 580 Km. Since the observed proton flux resulted from different source mechanisms a procedure was developed that allowed us to compute and separate the contributions made by different mechanisms in the observed protons. New evidence was derived from the study of the Down-Up asymmetry both along the field direction and the zenith of the look direction (ZAP angle) which substantiated the hypothesis that either one or both of the processes of the radial and the pitch angle diffusion play active roles in the origin and the distributions of the protons in the inner radiation belt. It was argued that processes drive the trapped protons in the radiation belt into the regions where stable trapping is not possible and thus contribute to the observed protons in these regions. We were further able to compute the total diffusing flux; however, it was assumed that both the Splash and the Re-entrant albedo proton fluxes were equal. Since this assumption was not very accurate, an incorrect estimation of the diffusing proton flux might have resulted. In addition to the above, the flux and the energy spectrum of the albedo protons were derived at three different regions. These were then compared with the results of other investigators. Discrepencies in both the flux and the energy spectrum were observed. Our flux value of 1.05 protons/m² -sec-ster-Mev for the Re-entrant albedo at an energy of 85 Mev in the region where L = 2.5 was about a factor of two and a half higher than estimated by Ray (1967). No west-east asymmetry was observed in the true proton flux (proton flux obtained by subtracting the background contamination from the observed proton flux), within the limits of the experimental error. Since such an asymmetry was expected if we assume that the albedo protons alone constitute the true protons, it was concluded …

Gravitational Motion: An Interaction?, Frank H. Meyer

Journal of the Minnesota Academy of Science

"Non-implications" in Newton's Law of Gravitation are discussed to emphasize different approaches in two books treating the subject: Dewey Larson's Beyond Newton, and Gravitation, by Misner, Thorne and Wheeler. The author notes that the latter book ignores the possibility that gravitation may not be an interaction; while Larson accepts Newton's Law of Gravitation as a mathematically valid statement of Kepler's Laws of Planetary Motion, thus being applicable to the sun and planets even if they are not actually interacting.

Una Roca Lunar En Barcelona, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

E.S.A., N.A.S.A. Europea…, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Pole Stars Of Other Planets, Paul C. Sharrah

Journal of the Arkansas Academy of Science

The north celestial pole of the Earth and the other planets is discussed. Right ascension and declination information on the location of the poles on the celestial sphere is summarized. The name of the brightest visible star near each pole is given and the special case of Uranus is discussed.

Geophysical Institute Annual Report 1974-75, Geophysical Institute

GI Reports

The 1974-75 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.

Thermal Instability In Supernova Shells, R. Mccray, R. F. Stein, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Thermal instability in the radiative cooling region behind a shock will cause upstream density fluctuations to collapse into thin sheets aligned parallel to the shock front. A linearized calculation demonstrates the development of this instability. Thermal conduction suppresses the development of small-scale perturbations. Estimates of the scale sizes for the fully developed condensations agree roughly with the scale sizes of fine structure observed in supernova shells such as the Cygnus Loop.