Showing papers by "San Jose State University published in 1989"

More than Cool Reason: A Field Guide to Poetic Metaphor

Abstract: "The authors restore metaphor to our lives by showing us that it's never gone away. We've merely been taught to talk as if it had: as though weather maps were more 'real' than the breath of autumn; as though, for that matter, Reason was really 'cool.' What we're saying whenever we say is a theme this book illumines for anyone attentive." -- Hugh Kenner, Johns Hopkins University "In this bold and powerful book, Lakoff and Turner continue their use of metaphor to show how our minds get hold of the world. They have achieved nothing less than a postmodern Understanding Poetry, a new way of reading and teaching that makes poetry again important." -- Norman Holland, University of Florida

Heterogeneous physicochemistry of the polar ozone hole

Abstract: Processes occurring in the polar winter stratosphere, which involve polar stratospheric clouds (PSCs), are investigated using observations from the Airborne Antarctic Ozone Experiment. In particular, data on the properties of PSCs and their physical chemistry, the microphysical processes and time constants for cloud processes, the heterogeneous chemical processes and their time constants, and nonlinearities in the long-term ozone trend associated with physical and chemical processes are examined. The chemical reactions leading to the depletion of the inert chlorine reservoir in a presence of type I PSCs are established, and it is shown that type II PSCs contribute to chemical processing that sustains the chemical imbalance of the polar stratosphere. It is shown that, using a simple model, the decadal evolution of the Antarctic ozone hole may be understood through nonlinearities in the heterogeneous chemistry, with possible contributing effects of variations in stratospheric temperatures and water vapor concentrations.

Physical processes in polar stratospheric ice clouds

Abstract: A one-dimensional model of cloud microphysics has been used to simulate the formation and evolution of polar stratospheric ice clouds. The model results are in general agreement with many of the observed properties of these clouds, including their optical properties, impact on water vapor, and particle size. It is found that the clouds must undergo preferential nucleation upon the preexisting aerosols, just as tropospheric cirrus clouds do. Therefore there is an energy barrier between stratospheric nitric acid particles and ice particles, implying that nitric acid does not form a continuous set of solutions between the trihydrate and ice. The Kelvin barrier is not significant in controlling the rate of formation of ice particles, except in air parcels that have cooled very slowly. We find that the cloud properties are very sensitive to the rate at which the air parcels cool. In wave clouds, with cooling rates of hundreds of degrees per day, most of the existing aerosols nucleate and become ice particles. Such clouds have particles with sizes of the order of a few microns, and optical depths of the order of unity, and are probably not efficient at removing materials from the stratosphere. In clouds that form with cooling rates of a few degrees per day or less, only a small fraction of the aerosols become cloud particles. In such clouds the particle radius is larger than 10 μm, the optical depths are low, and the water vapor is efficiently removed. These clouds are probably formed in air parcels as they circulate around the Antarctic vortex. Seasonal simulations show that the lowest water vapor mixing ratio is determined by the lowest temperature reached and that the time when clouds disappear is controlled by the time when temperatures begin to rise above the minimum values. Hence clouds occur in the early winter at temperatures that are higher than those at which clouds occur in the late winter. The rate of decline of cloud altitude is not an indication of the fall speed of individual particles nor of vertical air motion, as had been previously suggested. The altitude of the clouds declines during the winter because the temperatures in the Antarctic increase earlier at the higher altitudes. The ice clouds are not able to remove a significant amount of nitric acid through physical processes such as coagulation with, or nucleation upon, nitric acid aerosols. Such removal may occur through other processes, not included in our simulations, such as vapor phase transfer. A considerable amount of further work could be done to improve upon our simulations. Improvements would include a treatment of the three-dimensional structure of wave clouds, a more complete treatment of the interactions between clouds and atmospheric motions on the seasonal time scale, and a treatment of the nitric acid vapor phase interactions with ice particles. Laboratory studies of the vapor pressures of water and nitric acid above impure ice crystals are needed. In addition, laboratory investigations of the ice-nucleating properties of nitric acid crystals would be useful. Direct observations of the sizes and concentrations of the particles in clouds formed over a time period of a few days are not available and are important to obtain, since these dominate the sedimentation removal process.

Slotted Bolted Connections in Aseismic Design for Concentrically Braced Connections

Abstract: The use of concentrically braced steel frames to satisfy lateral force requirements is a common design practice in regions of strong seismicity. They provide a very efficient means of fulfilling the dual objectives of earthquake resistant design, that is, damage control and collapse prevention. While tensile yielding and inelastic buckling of bracing elements provide the basic energy absorbing mechanism, there are inherent problems with member behavior under multiple cycles of inelastic deformations. Inelastic energy dissapation, however, may also be provided by friction resistance in slotted bolted connections, thus eliminating the need for inelastic member buckling. Limited laboratory tests indicate that this concept may be a viable alternative for use as a lateral force resisting system for both new construction and the seismic upgrading of existing structures.

Visual acceleration detection: effect of sign and motion orientation.

Abstract: Thresholds for the detection of constant acceleration and deceleration of a discrete object moving along horizontal and vertical axes were studied. A staircase methodology was used to determine thresholds for three average velocities (0.7, 1.2, and 1.7 deg/sec). Thresholds, expressed as the proportion of velocity change, did not differ significantly among the average velocities; thus, a consistent Weber-like fraction is suggested by the data. Furthermore, there was an interaction between the axis of motion (horizontal or vertical) and the sign of the velocity change (acceleration or deceleration): accelerations were easier to detect along the vertical axis, decelerations along the horizontal axis.

Prevalence of back pain among fulltime United States workers.

Abstract: A source of data on the health and working conditions of a probability sample of United States workers, the Quality of Employment Survey for 1972-3 (QES73), is investigated for the first time to determine which groups of workers are more or are less likely to report back pain. Estimated coefficients from a logistic regression are used to calculate odds ratios and confidence intervals for various groups. Few previous studies on back pain among United States workers control for as many potentially confounding variables as are considered in this study and few use data from a national probability sample of workers. The following independent variables are judged to be important positive correlates based on their estimated odds ratios and confidence intervals: farm, service, blue collar, and clerical work; low levels of schooling and income; jobs needing physical effort; age between and including 50 to 64; and smoking. Marital separation was found to be negatively correlated with back pain. Caution should be exercised in attempting to generalise these findings, since the back pain variable is based on respondents' subjective evaluations. Moreover, the variable does not distinguish between lower or upper back or neck pain, nor is information on the duration or frequency of pain available.

Design of automated system for management of arrival traffic

Abstract: The design of an automated air traffic control system based on a hierarchy of advisory tools for controllers is described. Compatibility of the tools with the human controller, a key objective of the design, is achieved by a judicious selection of tasks to be automated and careful attention to the design of the controller system interface. The design comprises three interconnected subsystems referred to as the Traffic Management Advisor, the Descent Advisor, and the Final Approach Spacing Tool. Each of these subsystems provides a collection of tools for specific controller positions and tasks. The design of two of these tools, the Descent Advisor, which provides automation tools for managing descent traffic, and the Traffic Management Advisor, which generates optimum landing schedules is focused on. The algorithms, automation modes, and graphical interfaces incorporated in the design are described.

Condensed nitrate, sulfate, and chloride in Antarctic stratospheric aerosols

Abstract: The 1987 Airborne Antarctic Ozone Experiment, in which the NO3, Cl, and SO4 contents of stratospheric aerosols were estimated, is discussed. The aerosol size and chemical composition measurements were carried out on samples collected during August 17 to September 4, 1987. The data indicate that condensed nitrate is found below a threshold temperature of 193.6 + or - 3.0 K, which is generally found at latitudes exceeding 64 deg S. A negative correlation exists between condensed nitrate and ozone correlation.

Trauma, degenerative disease, and other pathologies among the Gombe chimpanzees.

Abstract: The well-known and extremely well-documented chimpanzees from Gombe National Park were analyzed for presence of skeletal pathologies. Of the 15 animals available for study, 11 were old and complete enough to permit systematic analysis. Of these, 10 showed some evidence of skeletal pathological involvement. The most common type of lesion seen resulted from trauma. Those chimps with the most fractures (Old Female, 3; Flo, 4; Hugo, 8) are consistently the oldest individuals in the sample. In addition to accidental falls, the most common cause of trauma was from interpersonal violence, resulting in bite wounds (see in two individuals) and fractures (see in three individuals). Conversely to trauma, degenerative disease was exceedingly rare in this population, found in no large intervertebral joints (N = 344) and only two major synovial joints (N = 186). In fact, the complete lack of osteophytosis, even in older individuals, stands in stark contrast to the situation seen in modern humans, perhaps in our species reflecting a biomechanical cost of bipedality.

Progressive propaganda critics and the magic bullet myth

Abstract: The standard account of the beginnings of American mass communication research holds that the propaganda critic between the world wars adopted the European concept of the mass audience, treating messages as “magic bullets”; directly and powerfully infused into passive receivers. Such a mythical account overlooks the progressive reformist mission of propaganda analysis to help an essentially competent public against the new co‐option of communication channels by powerful institutions. The magic bullet myth emerged after 1940 when social scientists turned from domestic to extra‐hemispheric threats to democracy and sought a consensus that propaganda was democracy's servant against fascism and communism.

Antarctic stratospheric ice crystals

Abstract: Ice crystals were replicated over the Palmer Peninsula at approximately 72 deg S on six occasions during the 1987 Airboirne Antarctic Ozone Experiment. The sampling altitude was between 12.5 and 18.5 km (45-65 thousand ft pressure altitude) with the temperature between 190 and 201 K. The atmosphere was subsaturated with respect to ice in all cases. The collected crystals were predominantly solid and hollow columns. The largest crystals were sampled at lower altitudes where the potential temperature was below 400 K. While the crystals were larger than anticipated, their low concentration results in a total surface area that is less than one tenth of the total aerosol surface area. The large ice crystals may play an important role in the observed stratospheric dehydration processes through sedimentation. Evidence of scavenging of submicron particles further suggests that the ice crystals may be effective in the removal of stratospheric chemicals.

Children's word structure knowledge: Implications for decoding and spelling instruction

Abstract: Research has shown that not all children internalize the structure of English orthography as they learn to decode and spell. In fact, many children have difficulty mastering these two skills. In this paper, the relevance of word structure knowledge to decoding and spelling instruction and performance is discussed. It was anticipated that explicit, discussion oriented, and direct decoding instruction based on word origin and structure would result in improved reading and spelling performance. During the instruction, students compared and contrasted letter-sound correspondences, syllable patterns, and morpheme patterns in English words of Anglo-Saxon, Romance, and Greek origin. Upper elementary grade students receiving the decoding instruction made significant gains in word structure knowledge and in decoding and spelling achievement.

Nature and timing of deformation in the Foothills terrane, central Sierra Nevada, California: Its bearing on orogenesis

Abstract: Detailed mapping and structural analysis combined with new age dates, using U-Pb and ^(40)Ar/^(39)Ar techniques, have allowed us to constrain the timing of pre-ductile and ductile deformation in the Foothills terrane of the central Sierra Nevada. By using strain and other data, it can be shown that rigid rotation of beds (folding/faulting) predated the onset of ductile deformation and probably occurred between 160 and 151 Ma. Ductile structures, consisting of continuous and secondary cleavages and associated folds and lineations, started forming ca. 151 Ma in the Bear Mountains fault zone and then ca. 145 Ma, began moving away from the fault zone, forming diachronously over an ∼30-m.y. period. The last documented ductile structure formed ca. 123 Ma, although some secondary structures may be younger. Metamorphism of these rocks is generally upper greenschist facies, although higher-grade belts (one bearing staurolite, andalusite, and sillimanite) are present. Strain was preferentially partitioned into one of these belts of higher metamorphic grade (and sporadically elsewhere). The structural history here is much more complex, and at least one and locally two complete transpositions of the original cleavage have occurred. In these zones of complex deformation, it is in most cases possible only to identify a composite foliation consisting of new continuous cleavage and relicts of earlier phases, all lying mutually parallel. Timing constraints indicate that the pre-ductile structures may correspond to a very late stage of the Nevadan orogeny (that is, 155 ± 3 Ma), but the ductile structures postdate that orogeny (as defined) by as much as about 25-30 m.y. Models which relate the ductile structures in the central Foothills terrane to Nevadan plate-tectonic events are untenable. In addition, recent work indicates that Late Cretaceous ductile deformation in the central and southern Sierra Nevada may be relatively widespread, indicating that tectonic models for the Sierra Nevada need to be reassessed.

Production of stable and radioactive nuclides in thick stony targets (R = 15 and 25 cm) isotropically irradiated with 600 MeV protons and simulation of the production of cosmogenic nuclides in meteorites

Abstract: Two artificial meteoroids made out of gabbro with a density of 3 g cm−3 with radii of 15 and 25 cm were isotropically irradiated with 600 MeV protons in order to simulate the production in meteoroids of cosmogonie nuclides by galactic cosmic ray protons. The depth dependent production of a wide range of radionuclides from target elements O, Mg, Al, Si, Ti, Fe, Co, Ni, Cu, Ba, Lu, and Au was measured. Furthermore, the production of He and Ne isotopes from Al, Mg, Si as well as from degassed meteoritic material was determined. Together with earlier results on an artificial meteoroid with a radius of 5 cm, and with data derived from thin-target experiments, the depth dependence of production rates is investigated for radii from 0 to 75 g cm−2. 60Co from Co shows the strongest size dependence; the center production rates differ by a factor of 100 for radii of 5 and 25 cm. Other low-energy products, like 58Co from Co and 24Na produced from Al, increase only up to a factor of 3.5 over the entire range of radii. For extreme high-energy products, in contrast, the center production rates decrease by up to a factor of 10. The observed depth profiles show a wide varity of shapes. Low-energy products have pronounced maxima in the center, high-energy products exhibit strong decreases from surface to center and, in between, essentially flat profiles are seen as well as such with a transition maximum. The spectra of primary protons and of secondary protons and neutrons in the artificial meteoroids were calculated using Monte Carlo techniques. The fluxes of secondary protons and neutrons depend strongly on depth and size, the spectral shapes being different for protons and neutrons. Calculating also the nucleon spectra which result from irradiation with real GCR p-spectra, the differences between simulation experiments and cosmic irradiation conditions are quantitatively described. On the basis of all these spectra and of thin-target excitation functions, production rates were calculated and compared with the experimental ones. The theoretical depth profiles allow to distinguish the different contributions of primary and secondary particles and to unravel the various production modes of cosmogenic nuclides in meteoroids. Our investigation shows that it is possible to model the production of residual nuclides in artificial meteoroids with excellent accuracy by thin-target calculations, provided that reliable thin-target excitation functions are at hand.

The nature of the near-infrared features on the venus night side

Abstract: Near-infrared images of the Venus night side show bright contrast features that move from east to west, in the direction of the cloud-top atmospheric superrotation. Recently acquired images of the Venus night side along with earlier spectroscopic observations allow identification of the mechanisms that produce these features, their level of formation, and the wind velocities at those levels. The features are detectable only at wavelengths near 1.74 and 2.3 micrometers, in narrow atmospheric windows between the CO_2 and H_2O bands. The brightest features have brightness temperatures near 480 Kelvin, whereas the darkest features are more than 50 Kelvin cooler. Several factors suggest that this radiation is emitted by hot gases at altitudes below 35 kilometers in the Venus atmosphere. The feature contrasts are produced as this thermal radiation passes through a higher, cooler, atmospheric layer that has horizontal variations in transparency. The 6.5-day east-west rotation period of the features indicates that equatorial wind speeds are near 70 meters per second in this upper layer. Similar wind speeds have been measured by entry probes and balloons at altitudes between 50 and 55 kilometers in the middle cloud layer. The bright features indicate that there are partial clearings in this cloud deck. The presence of these clearings could decrease the efficiency of the atmospheric greenhouse that maintains the high surface temperatures on Venus.

Symmetry, selection rules, and energy levels of Pr3+:Y3Al5O12

Abstract: Absorption, fluorescence, and site-selective excitation spectra of Pr 3+ : Y 3 Al 5 O 12 are reported between 0.4 and 6.7 μm at several temperatures between 1.6 and 90 K. The complexity of the spectra indicates that Pr 3+ ions occupy several different sites. The most intense spectra, representing the majority of the Pr 3+ ions in dodecahedral lattice sites, are analyzed on the basis of electric-dipole selection rules for D 2 site symmetry. Weak spectra are reported but not analyzed due to the difficulty in assigning levels to a particular site. Analyses of intense spectra establish the symmetry of 17 Γ 1 , 12 Γ 2 , 10 Γ 3 , and 12 Γ 4 Stark levels. These 51 levels are compared with the results of a crystal-field splitting calculation. A Hamiltonian consisting of Coulombic, spin-orbit, and crystal-field (D 2 symmetry) terms was diagonalized for all manifolds of the Pr 3+ (4f 2 ) configuration. The rms deviation between calculated and experimental levels is 11 cm −1 .

Dental pathologies in ten free-ranging chimpanzees from Gombe National Park, Tanzania.

Abstract: The dental remains of ten adult chimpanzees from Gombe National Park, Tanzania, were examined for enamel attrition, caries, abscesses, periodontal disease, and tooth loss. Age was the underlying factor in the development of dental pathology, in that enamel wear was present to some extent in all ten but was uniformly severe only in the three for whom estimated age at death was 39-43 years. In turn, enamel wear appears to have been the direct cause of abscess development, periodontal disease, and tooth loss. Periodontal disease was commonly expressed as alveolar resorption, particularly around the premolars and molars. This involvement was variable in all except the two youngest. Some interesting wear patterns were evident in the form of deep grooves in the upper incisors and dramatic notching of the lower canines. These patterns, and enamel attrition in general, were attributed to normal mastication and to various stripping activities. Only one carious lesion was observed, in a male with an estimated age of 26 years. An accurate assessment of the actual prevalence of caries was obscured by enamel wear and tooth loss in the older individuals.

The role of igneous sills in shaping the Martian uplands

Abstract: Relations among geologic units and landforms suggest that igneous sills lie beneath much of the intercrater and intracrater terrain of the Martian uplands. The igneous rocks crop out along the upland-lowland front and in crater floors and other depressions that are low enough to intersect the sill's intrusion horizons. It is suggested that heat from the cooling sills melted some of the ice contained in overlying fragmental deposits, creating valley networks by subsurface flow of the meltwater. Terrains with undulatory, smooth surfaces and softened traces of valleys were created by more direct contact with the sills. Widespread subsidence following emplacement of the sills deformed both them and the nonvolcanic deposits that overlie them, accounting for the many structures that continue from ridged plains into the hilly uplands. Crater counts show that the deposit that became valleyed, softened, and ridged probably began to form (and to acquire interstitial ice) during or shortly after the Middle Noachian Epoch, and continued to form as late as the Early Hesperian Epoch. The upper layers of this deposit, many of the visible valleys, and the ridged plains and postulated sills all have similar Early Hesperian ages. Continued formation of valleys is indicated by their incision of fresh-appearing crater ejecta. The dependence of valley formation on internal processes implies that Mars did not necessarily have a dense early atmosphere or warm climate.

Isotopic systematics of Pb/U (zircon) and 40Ar/39Ar (biotite-hornblende) from rocks of the central Foothills terrane, Sierra Nevada, California

Abstract: Pb/U zircon and ^(40)Ar/^(39)Ar biotite-horn-blende studies in conjunction with detailed structural and textural studies clarify the age and structural relations of a unique cluster of plutons in the central Sierra Nevada western metamorphic belt. The plutons range from gabbro to tonalite/trondhjemite and include the Guadalupe Igneous Complex. Magmatic emplacement ages for the plutons are for the most part between ∼150 and ∼145 m.y., as recorded in both the zircon and hornblende isotopic systems. Additional ages of 138 and 123 m.y. were determined on small plutons having key structural settings. In general, the Pb/U and ^(40)Ar/^(39)Ar isotopic systems are well behaved. Second-order complications are locally present in the Pb/U systems, owing to the entrainment of older zircon from wall rocks, and in ^(40)Ar/^(39)Ar systems, owing to minor compositional differences in mica and amphibole phases. The age data and structural relations of the plutons in conjunction with ^(40)Ar/^(39)Ar metamorphic wall-rock biotite and hornblende age data constrain regional ductile deformation in the study area to have occurred between ∼150 and ∼125 Ma. Such deformation was accompanied by upper greenschist- to lower amphibolite-facies metamorphism and is at least in part closely related to pluton emplacement. Such deformation and metamorphism has in the past been attributed to the Late Jurassic Nevadan orogeny. This study shows clearly, however, that ductile deformation and metamorphism in the study area are post-Nevadan if modern concepts of the Nevadan orogeny are strictly adopted.

Evidence for syntectonic intrusion of plutons in the Bear Mountains fault zone, California

Abstract: In the Foothills terrane, western metamorphic belt, California, the Bear Mountains fault zone (BMFZ)—a zone of complex, multiple deformation—has deformed composite maficfelsic granitoids of the Guadalupe igneous complex (GIC) and the Hornitos pluton at magmatic to upper amphibolite facies temperatures. Evidence for high-temperature deformation includes the occurrence of orthopyroxene, clinopyroxene, and brown hornblende in syndeformationally recrystallized aggregates in deformed rocks of the GIC and the occurrence of melt leucosomes in the axial surfaces of folds in cordierite—K-feldspar migmatites in contact metamorphic country rocks in the BMFZ. Away from the BMFZ, composite granitoids of the GIC show no evidence of magmatic flow, so that deformation of the GIC granitoids in the BMFZ was entirely by solid-state flow. This suggests that the GIC was intruded before this mylonitic deformation in the BMFZ. However, other evidence suggests some deformation in the BMFZ before intrusion of the pluton. In the Hornitos pluton components of composite granitoids showing relatively weak solid-state deformation are strongly elongate, suggesting a component of magmatic flow, although later subsolidus deformation also occurred in most places. Supporting evidence of magmatic flow in the Hornitos pluton also includes dimensional alignment of plagioclase laths and prismatic hornblende grains, as well as preferred orientation of twins in recrystallized aggregates of elongate grains of plagioclase. Away from the BMFZ, the regional metamorphic grade is low, suggesting that heat for the high-temperature deformation and metamorphism was supplied by the intrusions. U/Pb zircon ages are consistent with emplacement of the GIC and the Hornitos pluton, as well as their deformation in the BMFZ, around 150 Ma. 40 Ar/ 39 Ar ages of hornblende in foliations in the deformed granitoids and of biotite in foliations in the contact aureole rocks suggest that the plutons and the country rocks in the BMFZ remained hot enough for amphibolite to upper greenschist facies conditions to persist for 5 to 15 Ma after emplacement of the plutons.

A chemically bonded liquid crystal as a stationary phase for high performance liquid chromatography. Synthesis on silica via an organochlorosilane pathway

Abstract: A compound which becomes a liquid crystal when bonded to a polysiloxane was reacted with dimethylchlorosilane to produce a reagent suitable for bonding to a silica surface. After the silanization reaction was complete, the product was characterized by elemental analysis, diffuse reflectance Fourier transform Infrared Spectroscopy (DRIFT), CP/MAS carbon-13 NMR and differential scanning calorimetry (DSC). Preliminary chromatographic testing was done by retention index measurements using the alkylarylketone homologous series and by measuring the separation factor, α, for anthracene/phenanthrene at two different mobile phase compositions.

The Historical Development of J. J. Sylvester's Four Point Problem

Abstract: (1989). The Historical Development of J. J. Sylvester's Four Point Problem. Mathematics Magazine: Vol. 62, No. 5, pp. 309-317.

A study of cognitive mapping as a means to improve summarization and comprehension of expository text

Abstract: The study investigated the effects of cognitive mapping on written summarization and comprehension of expository text. Fifty‐one freshmen students participated in the study. The mapping treatment consisted of the development of cognitive maps which graphically illustrated the interrelationships of ideas in expository articles the students read. Following the treatment, students read three expository articles in the Organizational Patterns Test (OPT) with the following rhetorical organizations: enumeration, thesis‐proof, and problem‐solution. The mapping treatment groups scored significantly higher on holistic scores based on written summarizations of thesis‐proof and problem‐solution articles. Mapping treatment students also identified more details, which were used to support main ideas, than did nonmapping students. Moreover, mapping treatment groups used significantly more cohesive ties in writing their summarizations than did the nonmapping group. In addition, mapping students wrote longer and...