Showing papers by "San Jose State University published in 1986"

Optical dispersion relations for amorphous semiconductors and amorphous dielectrics.

Abstract: An expression for the imaginary part, k, of the complex index of refraction, N=n-ik, for amorphous materials is derived as a function of photon energy E: k(E)=A(E-${E}_{g}$${)}^{2}$/(${E}^{2}$-BE+C) where A, B, and C are positive nonzero constants characteristic of the medium such that 4C-${B}^{2}$g0. ${E}_{g}$ represents the optical energy band gap. The real part, n, of the complex index of refraction is then determined to be n(E)=n(\ensuremath{\infty})+(${B}_{0}$E+${C}_{0}$)/ (${E}^{2}$-BE+C) using Kramers-Kronig analysis, where ${B}_{0}$ and ${C}_{0}$ are constants that depend on A, B, C, and ${E}_{g}$, and n(\ensuremath{\infty}) is a constant greater than unity. Excellent agreement was found between these formulas and experimentally measured and published values of n and k of amorphous silicon, hydrogenated amorphous silicon, amorphous silicon nitride, and titanium dioxide.

Condensation of HNO3 and HCl in the winter polar stratospheres

Abstract: Nitric acid and hydrochloric acid vapors may condense in the winter polar stratospheres. Nitric acid clouds, unlike water ice clouds, would form at the temperatures at which polar stratospheric clouds (PSCs) are observed and would have optical depths of the magnitude observed suggesting that HNO3 is a dominant component of PSCs. ClO, N2O5 and ClNO3 may react on cloud particle surfaces yielding additional HNO3, HCl, and HOCL. In the vicinity of PSCs these reactions could deplete the stratosphere of photochemically active NO(x) species. The sedimentation of PSCs may remove these materials from the stratosphere. The loss of vapor phase NO(x) might allow halogen-based chemistry to create the ozone hole.

Missing the Boat and Sinking the Boat: A Conceptual Model of Entrepreneurial Risk:

Abstract: The use of financial portfolio theory to guide new venture planning is discussed and rejected. Instead, a dual conceptualization of business risk is offered that is more consistent with statistical...

The Adolescent Audience for Music Videos and Why They Watch.

Abstract: Aux Etats-Unis les adolescents passent en moyenne plus de deux heures par jour devant des videoclips. Les raisons qu'ils donnent sont differentes de celles habituellement invoquees par les amateurs de television ou les melomanes: il s'agit de «comprendre reellement» ce que le compositeur de la chanson, mise en scene par le videoclip, a «voulu dire»

Proximate and Ultimate Causation of Egg Size and the “Third-chick Disadvantage” in the Western Gull

Abstract: This is the publisher's version, also available electronically from http://www.jstor.org/stable/4087093?seq=1#page_scan_tab_contents.

Internal Hydrology and Geochemistry of Coral Reefs and Atoll Islands: Key to Diagenetic Variations

Abstract: Diagenetic changes in coral reef carbonates continue to generate both interest and controversy. Considerable attention has been devoted to carbonate porosity (Choquette and Pray 1970, Enos and Sawatsky 1981), pore-water geochemistry and diagenetic environments (Berner 1980, Longman 1980), and general geochemistry (Curtis 1977), but the subject of formation-scale fluxes and material balances has not received the attention it deserves. The rates, distributions, and mechanisms of fluid transport through the reef structure are basic to the understanding of diagenetic processes. Although some mineralogic transitions may be able to occur in a closed system (e.g., aragonite to calcite), others, such as dolomitization, require the passage of many volumes of pore water through the system in order to remove calcium and supply magnesium. Thus, the hydrogeology of a formation — porosity, permeability, the forces available to drive fluids through the system, and the evolution of these parameters over time — will exert important controls over the rate, nature, and extent of diagenesis. At the same time, diagenetic changes may provide important clues to formation hydrogeology and its development.

Crew factors in flight operations. Part 3: The operational significance of exposure to short-haul air transport operations

Abstract: Excessive flightcrew fatigue has potentially serious safety consequences. Laboratory studies have implicated fatigue as a causal factor associated with varying levels of performance deterioration depending on the amount of fatigue and the type of measure utilized in assessing performance. These studies have been of limited utility because of the difficulty of relating laboratory task performance to the demands associated with the operation of a complex aircraft. The performance of 20 volunteer twin-jet transport crews is examined in a full-mission simulator scenario that included most aspects of an actual line operation. The scenario included both routine flight operations and an unexpected mechanical abnormality which resulted in a high level of crew workload. Half of the crews flew the simulation within two to three hours after completing a three-day, high-density, short-haul duty cycle (Post-Duty condition). The other half flew the scenario after a minimum of three days off duty (Pre-Duty) condition). The results revealed that, not surprisingly, Post-Duty crews were significantly more fatigued than Pre-Duty crews. However, a somewhat counter-intuitive pattern of results emerged on the crew performancemeasures. In general, the performance of Post-Duty crews was significantly better than that of Pre-Duty crews, as rated by an expert observer on a number of dimensions relevant to flight safety. Analyses of the flightcrew communication patterns revealed that Post-Duty crews communicated significantly more overall, suggesting, as has previous research, that communication is a good predictor of overall crew performance.

Correlates of Vote Choice in the 1980 Presidential Primaries

Abstract: Four correlates of vote choice (issues, ideology, candidate qualities, and electability) are examined separately for each candidate competing in the 1980 presidential primaries. In general, candidate qualities were found to have the most frequent and consistent relationships with vote choice. Issues tended to be uncorrelated with candidate preference. Ideology was associated with vote choice only in the Republican primaries. Electability correlated with vote choice only in primaries held late in the nomination season. These patterns in the correlates of vote choice reflect patterns and changes in the candidates' campaigns.

Characteristics of polar stratospheric clouds during the formation of the Antarctic ozone hole

Abstract: Measured properties of Antarctic polar stratospheric clouds are described, and the possible relationship between the clouds and the formation of the ozone hole is considered. It is shown that the ozone hole develops and the clouds dissipate in the same place and at the same time. There may be a causal relationship between cloud particle evaporation and ozone depletion. A heterogeneous mechanism involving chemical reactions in the cloud droplets is suggested.

Coral Reef Hydrology: Field Studies of Water Movement within a Barrier Reef

Abstract: Water movement through the framework of Davies Reef, a coral reef in the central Australian Great Barrier Reef, was studied using field and laboratory determinations of permeability, tide gauge measurements of water levels, dye tracers, and pore water chemistry. Flow is driven by current, wind-induced, or tide-induced water level differences which were shown to occur between reef front and lagoon. The reef is hydraulically very heterogeneous with bulk flow occurring through high permeability zones (voids and rubble) at a velocity on the order of 10 m/d. Pore water exchange in less permeable zones occurs at a much slower rate. Vertical components of flow are significant. Chemical data indicate that carbonate precipitation and solution occur so that porosities, permeabilities, and flow paths may change with time. Implications for nutrient transfer through the benthic sediments and for fresh water resources on reef islands are discussed.

Proving Programs and Programming Proofs

Abstract: Publisher Summary Progress in applications to large-scale computer systems, depends on the design of new formal systems. This chapter raises some issues and makes a technical contribution by considering some theories of Feferman from the viewpoint of computer science, and comparing them with the theories of Martin-Lőf. The command language and assertion language of proving programs are discussed in the chapter. By “proving programs” is meant more explicitly: proving properties of programs or proving properties of the execution of programs. People speak of the “correctness” of a program with respect to its “specifications”—by this they mean that if the program gets an input of the kind it is designed for, it will produce an output having certain specified relations with the input. This notion is divided into the two notions of “total correctness” (an output is always produced and it is correct) and “partial correctness” (if an output is produced then it is correct).

The Value of User Image In Quelling Aberrant Consumer Behavior

Abstract: Shoplifting has reached epidemic proportions. Traditional approaches to keeping this behavior under control have met with limited success. This article explores the use of user image to decrease shoplifting. The analysis supports the approach. If the image of the “typical shoplifter” is made more negative, individuals anxious to disassociate themselves with the negative image will be less likely to shoplift.

A literature review of approaches to the professionalism of journalists

Abstract: This literature review of professionalism was prepared by San Jose State University graduate student Marianne Allison as a research committee project of the Mass Communication and Society Division, Association for Education in Journalism and Mass Communication. The project was prepared under the guidance of Professor Diana Stover Tillinghast. It reviews the literature on two approaches to professionalism in general and of the professionalism of journalists in particular: the “structural‐functionalist approach”; and the “power approach.”; Traditional and recent discussions of the nature of professionalism in occupational sociology are presented. Studies of the professionalism of journalists both in the United States and cross‐culturally are critiqued. The paper suggests several areas of fruitful research, and contains an extensive bibliography.

Sleep duration and eating behaviors of college students

Abstract: 31 short-sleeping college students tended to eat more small meals or snacks than 37 long sleepers, all of whom were satisfied with their sleep. This disrupted pattern of larger meals was predicted from work of Elomaa and Johansson with rats who were partially REM-sleep deprived.

Muon spin relaxation and knight shift in the heavy-fermion superconductor UPt 3

Abstract: Positive muon spin relaxation experiments have been conducted on the heavy-fermion superconductor UPt3 in both the normal and superconducting states for zero, transverse, and longitudinally applied magnetic fields. Below 6 K in zero applied field, the μ+ relaxation rate is approximately twice that expected from195Pt nuclear dipolar relaxation alone. Transverse- and longitudinal-field measurements show that the observe relaxation rate depends on magnetic field and is quasistatic in origin. It is suggested that the onset of very weak (≈10−3 μB/U atom) magnetic ordering below approximately 6 K is responsible for the observed increase in the relaxation rate. μ+ Knight shift measurements in the normal state of UPt3 show a temperature dependent shift Kμ which tracks the bulk susceptibility X. From the Kμ vs. X plot, a μ+ hyperfine field of approximately 100 Oe/μB is extracted.

Serial processing and the parallel-lines illusion: Length contrast through relative spatial separation of contours

Abstract: The distortion of perceived line length produced by the parallel-lines configuration reversed fromassimilation to contrast with large suprafoveal spatial separation of the contextual and test lines (Experiment 1). This new contrast effect was predicted by a pool-and-store model of size distortion (Girgus & Coren, 1982). However, contrary to the predictions of the model, the amount of spatial separation needed to produce the reversal did not depend on an absolute visual-angle (foveal) measure of separation. Rather, the reversal was determined by the relative spatial separation of contextual and test lines (Experiment 2); that is, small test lines required a smaller spatial separation from a contextual line to produce contrast than did larger test lines. On the basis of these findings, a revised pool-and-store model of length distortion is proposed.

Effect of adsorbed iron on thermoluminescence and electron spin resonance spectra of Ca-Fe-exchanged montmorillonite

Abstract: The ESR spectra and the natural and gamma-induced thermoluminescence (TL) glow curves of a series of variably cation-exchanged Fe-Ca-clays prepared from SWy-1 montmorillonite were examined. The ESR signal intensity associated with surface Fe increased linearly with surface Fe content up to a nominal concentration of 50 percent exchangeable Fe. At above 50 percent exchangeable Fe, no appreciable increase in the signal was noted. The TL intensity decreased linearly with increasing surface Fe up to 50 percent nominal exchangeable Fe. At above 50 percent, the signal was not appreciably further diminished. Possible effects of Fe on quenching of TL are considered.

Damage Detection in Offshore Platforms Using Vibration Information

Abstract: Damage detection based on changes in dynamic characteristics is considered for eight-legged k-braced steel offshore oil and gas production towers. Both experimental and analytical results are presented to improve damage detection capabilities. A 1/50th scale plastic model representing the structural system of a typical full-scale tower in 218 ft of water is used for the studies. Effects of severance of diagonal bracing members on selected vibration frequencies and mode shape parameters measurable at the deck are investigated. The effects of changes in deck mass, increase in jacket mass, and deck mass eccentricity on the selected parameters are also investigated and are shown to be different from the effects of damage.

Concentration and non-price competition in the recording industry

Abstract: This paper examines the effect of varying levels of concentration on a certain type of non-price competition in the recording industry. That dimension of rivalry is the quantity of new recordings released which, as our analysis shows, is likely to be directly related to the degree of musical innovation and diversity offered by the industry. Two theoretical models of the effects of concentration on recording firm behavior are developed and empirical tests are derived to determine if either model correctly predicts industry behavior. Examination of two sets of data suggests that increases in concentration may have led to fewer releases of new recordings, possibly as a result of collusive conduct.

Evolution of the Ordovician through Middle Pennsylvanian carbonate shelf in east-central California

Abstract: Carbonate shelf rocks marked by various sedimentary features suggesting intertidal to supratidal deposition or bearing rich, benthic faunas and their corresponding slope and basin rock sequences containing planktic fossils and sediment-gravity-flow deposits have been identified in the Inyo Mountains–Argus Range region of east-central California for all of the Paleozoic from Ordovician through Middle Pennsylvanian. Four major depositional sequences, each beginning with a marine transgression and all but the third ending with a progradation, were developed representing (1) Early Ordovician into Early Silurian time, (2) Early Silurian into earliest Middle Devonian time, (3) Middle to Late Devonian time and (4) Early to middle Late Mississippian time. A period of basinal infilling in the Late Mississippian was followed by a fifth major marine transgression in the Early Pennsylvanian. The carbonate shelf itself evolved from a homoclinal ramp in the Ordovician to an accretionary rimmed margin by the Early Devonian. This margin was drowned, probably in the Middle Devonian; by the Early Mississippian, a new homoclinal ramp had been developed. Before the end of the Mississippian, this ramp became distally steepened and then was transformed into an accretionary rimmed margin. The Early to Middle Pennsylvanian marine transgression gave rise to still another homoclinal carbonate ramp. Subsidence of ∼2,300 m occurred between Early Ordovician and Middle Pennsylvanian time in the area immediately east of the Inyo Mountains. It increased westward to probably >3,500 m at the edge of the Owens Valley as the continental margin subsided and bent downward ∼1° between Early Ordovician and middle Late Mississippian time. As a result of subsidence and relatively low rates of sedimentation, the water depth in the western part of the study area increased from close to sea level at the beginning of the Ordovician to as much as 3,000 m in the Late Mississippian. Because of higher rates of sediment accumulation and lower rates of subsidence in the eastern part of the region, shallow-water environments were maintained throughout most of this time interval; even so, the shelf-slope break retreated at least 45 km southeastward from Middle Ordovician to middle Late Mississippian time and at least 35 km farther southeastward by Middle Pennsylvanian time.

Selective Participation: Presidential Primary Voters as a Subset of General Election Voters

Abstract: Presidential primary voters constitute a subset of presidential election voters. Two hypotheses are explored to explain this selective pattern of participation. One hypothesis centers on characteristics of individual voters, whereas the other centers on characteristics of the political environment. The research supports the second hypothesis for Republicans, who were mobilized to vote in the primaries by aspects of the campaign and legal structures. Participation in Democratic primaries, however, was influenced by both contextual and individual factors. Differences between the 1980 Democratic and Republican nomination races are suggested as reasons for the divergent explanations found for participation in the two parties' primaries.

Length contrast in the Müller-Lyer figure: functional equivalence of temporal and spatial separation.

Abstract: The distortion of perceived line length produced by the Muller-Lyer figures reverses fromassimilation to contrast under conditions of temporal separation of contextual fins from judged shaft (Experiment 1) and spatial separation of contextual and judged elements (Experiment 2). In both experiments, the outgoing fins produced underestimation of judged shaft length whereas ingoing fins produced overestimation. These findings were predicted by the “pool and store” model of perceptual distortions (Girgus & Coren, 1982) and point to the need for a unified model of assimilation and contrast of perceived size. Extensions and refinements of the “pool and store” model are proposed.

Laboratory investigations of Mars: chemical and spectroscopic characteristics of a suite of clays as Mars soil analogs.

Abstract: Two major questions have been raised by prior explorations of Mars. Has there ever been abundant water on Mars? Why is the iron found in the Martian soil not readily seen in the reflectance spectra of the surface? The work reported here describes a model soil system of Mars Soil Analog Materials, MarSAM, with attributes which could help resolve both of these dilemmas. The first set of MarSAM consisted of a suite of variably iron/calcium-exchanged montmorillonite clays. Several properties, including chemical composition, surface-ion composition, water adsorption isotherms, and reflectance spectra, of these clays have been examined. Also, simulations of the Viking Labeled Release Experiment using the MarSAM were performed. The results of these studies show that surface iron and adsorbed water are important determinants of clay behavior as evidenced by changes in reflectance, water absorption, and clay surface reactions. Thus, these materials provide a model soil system which reasonably satisfies the constraints imposed by the Viking analyses and remote spectral observations of the Martian surface, and which offers a sink for significant amounts of water. Finally, our initial results may provide insights into the mechanisms of reactions that occur on clay surfaces as well as a more specific approach to determining the mineralogy of Martian soils.

Activity analysis: agreement among factors in a sensory processing model.

Abstract: A laboratory model designed to study tasks, activities, and occupation components is described. The feasibility of the model for gathering evidence about inherent factors perceived by participants in five discrete situations that involved spinning, drawing, manual rolling, buttoning, and chewing was tested. Results provide limited but specific evidence to support the concept that tasks, activities, and occupation components possess inherent factors that may be used in assessment and intervention to affect the interrelationships among external actions, external objects, and internal mental operations. Such evidence strengthens the credibility of emerging occupational theory for the practice of occupational therapy.

Rates of Landsliding as Impacted by Timber Management Activities in Northwestern California

Abstract: The impacts on the rates of landsliding by forest management activities (road construction and timber harvesting) in northwestern California are evaluated. The effects of these land disturbing activities were studied for various geomorphic zones of a watershed, valley inner gorges, land with slopes greater than 80 percent, and “other” watershed lands. Analysis of historical aerial photography and computer generated digital terrain slope maps was used to determine changes over time in the distribution of active landslides in third order watersheds, where the present watershed conditions vary from pristine to highly disturbed. In all of the disturbed watersheds, forest management activities increased the landslide rates (landslides per square mile) of each geomorphic zone. The valley inner gorges and land with slopes greater than 80 percent had the greatest landslide rate increases. Managed valley inner gorges and managed slopes greater than 80 percent had 11 to 26 and 3 to 26 times more landslides per square mile than managed “other lands,” respectively. These data suggest that the valley inner gorges and land with slopes greater than 80 percent are the most landslide prone geomorphic zones in a watershed and the most sensitive to forest management activities.