A library management information system in a multi-campus environment

The Office of Library Services in the Central Administration of the State University of New York (SUNY) has, since 1975, been developing a library management information system based on the analysis of library and other bibliographic and academic data which are available in machine readable form. Although primarily designed for the SUNY libraries, the processes are applicable in other academic libraries because of the general availability of the data used in the system. The task has changed over the years as new ideas and opportunities were realized, as new appreciations of the obtained results were attained, and as the technical environment has evolved. Nonetheless, the fundamental structure of the system design has not changed since the first ideas in 1974. This is an interim report. Progress has been agonizingly slow for two reasons. First, the difficulty of obtaining support and resources has been a real hindrance; the work has been squeezed into overcrowded schedules and ever-straitening budgets. Second, many of the machine-readable data which one confidently felt would be available in the late 1970s or very early 1980s are still not available. Some years, at least, will pass before the work can be completed as we see it now. Who knows what new ideas and opportunities will emerge as new results become available? Nonetheless, enough has been achieved to justify this report.published or submitted for publicatio

Atomic oxygen effects on metals

The effect of specimen geometry on the attack of metals by atomic oxygen is addressed. This is done by extending the coupled-currents approach in metal oxidation to spherical and cylindrical geometries. Kinetic laws are derived for the rates of oxidation of samples having these geometries. It is found that the burn-up time for spherical particles of a given diameter can be as much as a factor of 3 shorter than the time required to completely oxidize a planar sample of the same thickness

Experimental results on atomic oxygen corrosion of silver

The results of an experimental study of the reaction kinetics of silver with atomic oxygen in 10 degree increments over the temperature range of 0 to 70 C is reported. The silver specimens, of the order of 10,000 A in thickness, were prepared by thermal evaporation onto 3 inch diameter polished silicon wafers. There were later sliced into pieces having surface areas of the order of 1/4 to 1/2 square inch. Atomic oxygen was generated by a gas discharge in a commercial plasmod asher operating in the megahertz frequency range. The sample temperature within the chamber was controlled by means of a thermoelectric unit. Exposure of the silver specimens to atomic oxygen was incremental, with oxide film thickness measurements being carried out between exposures by means of an automated ellipsometer. For the early growth phase, the data can be described satisfactorily by a logarithmic growth law: the oxide film thickness increases as the logarithm of the exposure time. Furthermore, the oxidation process is thermally activated, the rate increasing with increasing temperature. However, the empirical activation energy parameter deduced from Arrhenius plots is quite low, being of the order of 0.1 eV

Classical radiation by free-falling charges in de Sitter spacetime

We study the classical radiation emitted by free-falling charges in de Sitter spacetime coupled to different kinds of fields. Specifically we consider the cases of the electromagnetic field, linearized gravity and scalar fields with arbitrary mass and curvature coupling. Given an arbitrary set of such charges, there is a generic result for sufficiently late times which corresponds to each charge being surrounded by a field zone with negligible influence from the other charges. Furthermore, we explicitly find a static solution in the static patch adapted to a charge (implying no energy loss by the charge) which can be regularly extended beyond the horizon to the full de Sitter spacetime, and show that any other solution decays at late times to this one. On the other hand, for non-conformal scalar fields the inertial observers naturally associated with spatially flat coordinates will see a non-vanishing flux far from the horizon, which will fall off more slowly than the inverse square of the distance for sufficiently light fields (m^2 + \xi R < 5H^2/4) and give rise to a total integrated flux that grows unboundedly with the radius. This can be qualitatively interpreted as a consequence of a classical parametric amplification of the field generated by the charge due to the time-dependent background spacetime. Most of these results do not hold for massless minimally coupled scalar fields, whose special behavior is analyzed separately.Comment: 31 pages, REVTeX4, minor changes, one reference added, version to appear in Phys. Rev.

Evolution of attached and detached slabs and their associated mantle dynamics

Over the two years of the NASA grant, this project has produced a significant amount of research results related to the plate subduction process and the surface crustal deformation at convergent boundaries (i.e., above subduction zones). While some research objectives are completely accomplished, other research tasks remain active and continue to be investigated at present. A steady state analytic thermal model for subducting slabs was used to examine the torques acting on a descending slab. It is found that gravitational torque vanishes when a slab is dipping either vertically or horizontally, unlike previous studies indicating that the magnitude of gravitational torque decreases as dip angle increases. Subsequently, a new time-dependent, analytic thermal model for a subducting slab was developed. The new model enables us to study transient phenomena associated with plate subduction analytically. On the basis of this model, the nature of slab dip angles was evaluated. Slab dip angles are found to be transient features. As they penetrate into the mantle and increase their lengths, the associated gravitational torque also increases resulting in a downward pulling of the slab to the steeper dip angle. This is especially true once a slab penetrates the olivine-spinel phase boundary at about 400 km depth. However, if the phase transformation does not follow the equilibrium condition, the gravitational torque may have a different behavior. This problem was investigated. Except for fast descending slabs, non-equilibrium phase transformation can only slow down the transient increase of slab dip angles discussed earlier. Its effect is not sufficiently strong to reverse the downward pulling for most of the slabs. However, when slabs subducting at 10 cm/yr or faster, a sufficient amount of metastable olivine can exist beneath 400 km. Because of its low density compared with the surrounding spinel, an upward buoyancy is produced resulting in an upward bending of the slab and possibly an upward rotation of the slab such that smaller dip angles are formed. Seismic studies of the Japanese Slab seem to support this interpretation. The development of oroclinal geometries at convergent boundaries was also examined to study plate obduction which is an important ingredient to the initiation of plate subduction. Although the study suggests that surface features are better modeled by block models, the large scale deformation can be adequately studied by viscous models. Such a model is now under development to complete our original objective to study the initiation of plate subduction. Finally, a three-dimensional, finite element, spherical convective model is developed to study dynamic plate subductions. The model development is now complete and it is being tested to ensure its proper operation. The model is able to generate convection results with a viscosity contrast of about 100. Our research continues to push the viscosity contrast to a level that is appropriate for a subducting slab

Dipole Oscillations of a Bose-Einstein Condensate in Presence of Defects and Disorder

We consider dipole oscillations of a trapped dilute Bose-Einstein condensate in the presence of a scattering potential consisting either in a localized defect or in an extended disordered potential. In both cases the breaking of superfluidity and the damping of the oscillations are shown to be related to the appearance of a nonlinear dissipative flow. At supersonic velocities the flow becomes asymptotically dissipationless.Comment: 4 pages, 4 figure