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Portland State University

1988

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Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

Roughness-Induced Resonance For Molecular Fluorescence Near A Corrugated Metallic Surface, P.T. Leung, Young Sik Kim, Thomas F. George Nov 1988

Roughness-Induced Resonance For Molecular Fluorescence Near A Corrugated Metallic Surface, P.T. Leung, Young Sik Kim, Thomas F. George

Physics Faculty Publications and Presentations

Based on a dynamical energy-transfer theory for the molecular decay rate near a rough metallic surface, a new resonance structure is predicted which is mediated by the roughness and which is absent in the static image theory. The implication of this new resonance structure to other phenomena, such as electron-energy-loss spectrum and cross coupling in thin films, is pointed out.


Dynamics Of Intermediate-Size Stream Outlets, Northern Oregon Coast, Ellen Eberhardt Oct 1988

Dynamics Of Intermediate-Size Stream Outlets, Northern Oregon Coast, Ellen Eberhardt

Dissertations and Theses

This study measured and evaluated the relation of coastal foredune morphology to stream beach outlets, and investigated the processes associated with the stream outlet. Intermediate-size streams were studied, and defined as those that flow across the beach most of the year but have no tidal influence. Fifty-four of these streams were found along the northern Oregon coast between the Columbia River and Yaquina Bay. Crescent Lake Outlet, Saltair Creek and Daley Lake Outlet were chosen as study streams for further investigation.


Analysis Of Ferredoxin And Flavodoxin In Anabaena And Trichodesmium Using Fast Protein Liquid Chromatography, Karen Lorraine Jones Jul 1988

Analysis Of Ferredoxin And Flavodoxin In Anabaena And Trichodesmium Using Fast Protein Liquid Chromatography, Karen Lorraine Jones

Dissertations and Theses

Iron is an essential nutrient for growth of photosynthetic microorganisms such as cyanobacteria and algae. Iron is required for proteins involved in the important processes of carbon and nitrogen assimilation. Low concentrations of iron in cultures or natural waters can lead to iron limitation which affects many aspects of algal metabolism. In natural waters, iron limitation can have effects on the patterns and rates of primary productivity.

The cellular content of certain proteins can be affected by media iron concentrations. Methods have been used that assay components of the cell as an indirect measure of iron nutritional status. For example, …


The Decay And Formation Of One-Dimensional Nonconservative Shocks, Marek Elźanowski, Marcelo Epstein Jun 1988

The Decay And Formation Of One-Dimensional Nonconservative Shocks, Marek Elźanowski, Marcelo Epstein

Mathematics and Statistics Faculty Publications and Presentations

The method of singular surfaces is used to obtain explicit conditions under which a one-dimensional acceleration wave develops into a shock when some dissipation mechanism is present. The conditions which secure the initial growth of the strong shock wave propagating into an undeformed nonlinear and dissipative medium are also derived. The analysis is pre- sented for a single balance law, one-dimensional elasticity, and the non- linear Maxwellian continuum.


The Mechanism Of Intrusion Of The Inyo Dike, Long Valley Caldera, California, Ze'ev Reches, Jonathan H. Fink May 1988

The Mechanism Of Intrusion Of The Inyo Dike, Long Valley Caldera, California, Ze'ev Reches, Jonathan H. Fink

Geology Faculty Publications and Presentations

We analyze the intrusion of the 11-km-long lnyo Dike at the margins of Long Valley caldera, eastern California. The dike trends N07°W and is divided into at least three segments which are rotated by as much as 25° with respect to the main trend. The dike seems affected primarily by the regional stress field of right-lateral shear of the western United States and by the local thermal conditions of the crust; the dike seems unaffected by the preexisting caldera margins and Sierra-Nevada frontal fault system. The high heat flow in Long Valley caldera implies that crustal rocks below 3-4.5 km …


Ionization Of K-Shell Electrons By Highly Relativistic Protons, M. L. Rustgi, P.T. Leung, S. A. Long Apr 1988

Ionization Of K-Shell Electrons By Highly Relativistic Protons, M. L. Rustgi, P.T. Leung, S. A. Long

Physics Faculty Publications and Presentations

A comparative study of three decent theoretical formalisms by Anholt, Scofield, Becker, and coworkers (1978-85) for K-shell ionization by highly relativistic protons has been carried out. The importance of the spin-flip mechanism is emphasized. It is concluded that in the analysis of such inner-shell ionization processes, an accurate description of the projectile-target interaction is of much more significance than the accuracy of the wave functions of the atomic electrons.


Limitation Of The Semirelativistic Approach In Sum Rules And Related Calculations In Atomic Physics, M. L. Rustgi, P.T. Leung, S. A. Long Mar 1988

Limitation Of The Semirelativistic Approach In Sum Rules And Related Calculations In Atomic Physics, M. L. Rustgi, P.T. Leung, S. A. Long

Physics Faculty Publications and Presentations

It is shown that the semirelativistic approach, when applied consistently to atomic calculations involving the Thomas-Reiche-Kuhn sum rule or its applications, may lead to very inaccurate results.


A Lagrangian For A System Of Two Dyons, Rainer Georg Thierauf Jan 1988

A Lagrangian For A System Of Two Dyons, Rainer Georg Thierauf

Dissertations and Theses

Maxwell's equations for the electromagnetic field are symmetrized by introducing magnetic charges into the formalism of electrodynamics. The symmetrized equations are solved for the fields and potentials of point particles. Those potentials, some of which are found to be singular along a line, are used to formulate the Lagrangian for a system of two dyons (particles with both electric and magnetic charge). The equations of motion are derived from the Lagrangian. It is shown that the dimensionality constants k and k * , which we r e introduced to define the units of the electromagnetic fields, have to be equal …


Geochemical Stratigraphy Of The Dooley Rhyolite Breccia And Tertiary Basalts In The Dooley Mountain Quadrangle, Oregon, David Neale Whitson Jan 1988

Geochemical Stratigraphy Of The Dooley Rhyolite Breccia And Tertiary Basalts In The Dooley Mountain Quadrangle, Oregon, David Neale Whitson

Dissertations and Theses

The Dooley Rhyolite Breccia in northeast Oregon was erupted between 12 and 16 million years ago, from central vents and linear feeder dikes within the Dooley Mountain quadrangle. The peraluminous, high-silica rhyolites of the formation were erupted over an irregular highland of eroded pre-Tertiary metamorphic rocks locally overlain by intracanyon, Eocene Clarno-type basalt flow(s) . The Dooley Rhyolite Braccia is exposed in a tectonically disrupted, north-south trending graben across the Elkhorn Range. The formation is variable in thickness with maximum thickness exceeding 660 meters in the south and 600 meters in the north half of the quadrangle. Volumetrically the formation …


Rock Slope Stability Studies In Siskiyou National Forest, Greg Visconty Jan 1988

Rock Slope Stability Studies In Siskiyou National Forest, Greg Visconty

Dissertations and Theses

The line mapping method of Piteau and Martin (1977) was tested on two different rock type road cuts in the Siskiyou National Forest, and was found to be an efficient means of collecting geological data for rock slope stability analysis. The unbiased approach of this method calls for close scrutiny of the outcrops in question, covering more ground than other methods in less time. In turn, this close attention to every crack in the outcrop reveals more about the stability of the slope, and can reveal hidden hazards of rock fall.

The supportive systems for analyzing the data - stereonets …


A Geochemical Study Of The Eagle Creek Formation In The Columbia River Gorge, Oregon, Rachel Ann Carlin Jan 1988

A Geochemical Study Of The Eagle Creek Formation In The Columbia River Gorge, Oregon, Rachel Ann Carlin

Dissertations and Theses

The Early Miocene Eagle Creek Formation, a series of volcanic mudflows and debris flows, is exposed in the Columbia River Gorge about 64 kilometers east of Portland, Oregon. Eighty-seven samples were analyzed using instrumental neutron activation analysis for trace element concentrations. Eleven samples were analyzed by Dr. Peter Hooper at Washington State University using X-ray Fluorescence for major element chemistry. These data were used to determine that the Eagle Creek Formation compositionally ranges from andesite to dacite.


Metasomatism Between Amphibolite And Metaultramafic Rocks During Upper Amphibolite Facies Metamorphism, Tobacco Root Mountains, Southwest Montana, William Robert Mcculloch Jan 1988

Metasomatism Between Amphibolite And Metaultramafic Rocks During Upper Amphibolite Facies Metamorphism, Tobacco Root Mountains, Southwest Montana, William Robert Mcculloch

Dissertations and Theses

The purpose of this study is to characterize the metasomatism that has taken place as a result of the chemical incompatibility between mafic and metaultramafic bulk compositions during high-grade regional metamorphism in the Tobacco Root Mountains, southwest Montana. Metasomatism of these rocks took place by both diffusionand infiltration-dominated processes. The result of these processes are characterized mineralogically and geochemically in the rocks.


A Fractal Analysis Of Diffusion Limited Aggregation, Cliff Myers Jan 1988

A Fractal Analysis Of Diffusion Limited Aggregation, Cliff Myers

Dissertations and Theses

A modified Witten-Sander algorithm was devised for the diffusion-limited aggregation process. The simulation and analysis were performed on a personal computer. The fractal dimension was determined by using various forms of a two-point density correlation function and by the radius of gyration. The results of computing the correlation function with square and circular windows were analyzed. The correlation function was further modified to include the edge from analysis and those results were compared to the fractal dimensions obtained from the whole aggregate. The fractal dimensions of 1.67 ± .01 and 1.75 ± .08 agree with the accepted values. Animation of …


Medium Resolution Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky Jan 1988

Medium Resolution Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky

Chemistry Faculty Publications and Presentations

An atmospheric pressure ionization (API) source for a VG 7070E‐HF mass spectrometer has been built and successfully operated at an accelerating potential of 6 kV. Hydrated protons and hydrated organic ions formed in the API source can be either partially or completely disaggregated by collisionally induced dissociation before entering the mass analyzer. The protonated molecular ions of pinacolone and 2,4‐pentanedione can be fully separated (R=2800, m/z 101,


Discharge Suppression System For A Double Focusing, Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky Jan 1988

Discharge Suppression System For A Double Focusing, Atmospheric Pressure Ionization Mass Spectrometer, Andrew H. Grange, Robert J. O'Brien, Douglas F. Barofsky

Chemistry Faculty Publications and Presentations

An electrical discharge suppression system for a medium throughput (∼2 l/s) pumping line has been devised that works up to potentials of ±15 kV. This device permits atmospheric pressure ionization sources to be interfaced to high-resolution, magnetic sector mass spectrometers with source potentials of 6-10 kV