Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Saturated Solar Ponds: Modified Equations And Results Of A Laboratory Experiment, Markus Karl Rothmeyer Dec 1979

Saturated Solar Ponds: Modified Equations And Results Of A Laboratory Experiment, Markus Karl Rothmeyer

Physics & Astronomy ETDs

The diffusion equation for salt gradient solar ponds has been modified to include the Soret effect (a thermal cross-effect due to the temperature gradient). The contribution of the Soret effect to the diffusion flux of salt is shown to be on the order of 4% in the winter and 28% in the summer for the UNM NaCl solar pond. The traditional stability criterion for solar ponds remains practically unchanged by the Soret effect. However, the contribution of non-constant properties (diffusion coefficient, thermal diffusivity and viscosity)--which have been neglected so far--seems to be significant. Saturated solar ponds are described by a …


Magnetohydrodynamic Effects On The Growth Of Condensations In An Expanding Universe & The Formation Of Galaxies, Charles Evans Aug 1979

Magnetohydrodynamic Effects On The Growth Of Condensations In An Expanding Universe & The Formation Of Galaxies, Charles Evans

Masters Theses & Specialist Projects

We review the evidence for existence of a magnetic field of the galaxy and whatever evidence there is of an intergalactic magnetoionic medium. We then consider the magnetohydrodynamics (MHD) of such a medium. The formation of galaxies through purely gravitational means in an expanding universe is then reviewed. Next the role of magnetohydrodynamics in such a universe is analyzed for their effects on galaxy formation. Finally, the importance of MED behavior in the early universe is emphasized from physical considerations and from present day evidence. Appendices discuss isotropic cosmologies, magnetic fields in such a background, the detailed MHD perturbations, and …


Simulative Investigation Of The Detection Of Modes Of Luminosity Variation In Astrophysical Sources, James Collins May 1979

Simulative Investigation Of The Detection Of Modes Of Luminosity Variation In Astrophysical Sources, James Collins

Masters Theses & Specialist Projects

Five astronomical data analysis methods were evaluated, using computer simulation techniques, for minimum detection levels, periodicity detection, and parameter estimation sensitivities. The evaluation of these methods was accomplished using three basic waveforms with the addition of ten “random” noise samples from a Gaussian distribution of known parameters. The chi-square and t-test methods were evaluated in detecting low-amplitude variability and brightness level shifts. Results indicate both methods have a strong dependence on the estimation of the standard deviation (σ) where a 0.1 change in σ will affect detection rates by ten to twenty-five percent at the ninety-five percent confidence level. The …


Ca Ii H And K And Hydrogen-Line Variations In V471 Tauri (=Bd + 16°516), Terry D. Oswalt Apr 1979

Ca Ii H And K And Hydrogen-Line Variations In V471 Tauri (=Bd + 16°516), Terry D. Oswalt

Publications

Spectroscopic and narrow-band photoelectric observations of the white dwarf eclipsing binary V471 Tau (= BD + 16°516) are reported. Periodic fluctuations in Ca IIH and K emission and Ha absorption, and a wave-like distortion of the light curve mimic the characteristics of several well-observed RS CVn binaries. A probable correlation between maximum emission-line strength and wave minimum is shown to exist.


Identification Of Cosmic Particles 3695 Mev/C2 And 3105 Mev/C2, Frank H. Meyer, Ronald W. Satz Jan 1979

Identification Of Cosmic Particles 3695 Mev/C2 And 3105 Mev/C2, Frank H. Meyer, Ronald W. Satz

Journal of the Minnesota Academy of Science

No abstract provided.


Interplanetary Magnetic Field Sector Polarity And Neuropsychiatric Adaption: A Reanalysis, Hans W. Wendt Jan 1979

Interplanetary Magnetic Field Sector Polarity And Neuropsychiatric Adaption: A Reanalysis, Hans W. Wendt

Journal of the Minnesota Academy of Science

Recent Russian studies reported associations between adaptation syndromes and (solar activity-related) interplanetary magnetic field (IMF) sector polarity. Certain ambiguities in the original work suggested some reanalyses, based on the graphs and data made available. Syndrome status exhibited a biphasic (semi annual) trend. It also correlated with specific geomagnetic changes during magnetic storms and possibly after sudden impulses. Moreover, lag effects and higher order interactions were noted among all parameters investigated. The restudy tends to support some of the original findings but also suggests new conclusions regarding potential relationships between geophysical/solar and psychophysiological processes.


Ionization, Luminosity, And Heating Of The Upper Atmosphere Of Mars, Jane L. Fox, Alexander Dalgarno Jan 1979

Ionization, Luminosity, And Heating Of The Upper Atmosphere Of Mars, Jane L. Fox, Alexander Dalgarno

Physics Faculty Publications

A model based upon Viking data is constructed of the Martian atmosphere, and a comprehensive quantitative discussion is given of the measurements of the ultraviolet dayglow. A detailed assessment is made of the heating of the neutral and ionized components of the atmosphere arising from the absorption of ultraviolet solar radiation.


Sporadic Mass Ejection In Red Supergiants, Menas Kafatos, A. G. Michalitsianos Jan 1979

Sporadic Mass Ejection In Red Supergiants, Menas Kafatos, A. G. Michalitsianos

Mathematics, Physics, and Computer Science Faculty Articles and Research

We have applied a general mechanism first proposed by J. A. Burke to red supergiants for determining the spin-down rate and angular momentum loss of rotating stars. This model relies principally on sporadic mass ejection, which is assumed to be the result of turbulent elements accelerating material in cool supergiant.atmospheres. Mass is preferentially expelled in the forward direction of rotation, resulting in a rapid loss of angular momentum on time scales of 1Q^4-10^6 years in the supergiant evolutionary phase. Such rotational breaking will occur if the turbulent elements have characteristic sizes a few percent of the stellar radius, and rms …


Penrose Pair Production As A Power Source Of Quasars And Active Galactic Nuclei, Menas Kafatos, D. Leiter Jan 1979

Penrose Pair Production As A Power Source Of Quasars And Active Galactic Nuclei, Menas Kafatos, D. Leiter

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we propose a new mechanism, Penrose pair production in massive, canonical (with a/M = 0.998) Kerr black holes, as a power source in quasars, Seyfert galaxies, radio galaxies, and BL Lac objects (i.e., what one usually refers to as active nuclei). As a working hypothesis, we postulate that massive (10^8 M0 or around this value) Kerr black holes reside in the centers of these objects. We also postulate that an accretion disk is formed. In a variety of models, hot, inner disks are expected. If the temperature is sufficiently high-as, for example, in the two-temperature model-then MeV …