27 research outputs found

    Axial morphology along the Southern Chile Rise

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    Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Geology 315-318 (2012): 58-63, doi:10.1016/j.margeo.2012.06.001.Morphology of four spreading segments on the southern Chile Rise is described based on multi-beam bathymetric data collected along the axial zones. The distribution of axial volcanoes, the character of rift valley scarps, and the average depths vary between Segment 1 in the south, terminating at the Chile Triple Junction, and Segment 4 in the north, which are separated by three intervening transform faults. Despite this general variability, there is a consistent pattern of clockwise rotation of the southern-most axial volcanic ridge within each of Segments 2, 3, and 4, relative to the overall trend of the rift valley. A combination of local ridge-transform intersection stresses and regional tectonics may influence spreading axis evolution in this sense.This work was supported by NOAA/OE grant NA08OAR4600757 and University of California Ship Funds

    Metastability in Two Dimensions and the Effective Potential

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    We study analytically and numerically the decay of a metastable phase in (2+1)-dimensional classical scalar field theory coupled to a heat bath, which is equivalent to two-dimensional Euclidean quantum field theory at zero temperature. By a numerical simulation we obtain the nucleation barrier as a function of the parameters of the potential, and compare it to the theoretical prediction from the bounce (critical bubble) calculation. We find the nucleation barrier to be accurately predicted by theory using the bounce configuration obtained from the tree-level (``classical'') effective action. Within the range of parameters probed, we found that using the bounce derived from the one-loop effective action requires an unnaturally large prefactor to match the lattice results. Deviations from the tree-level prediction are seen in the regime where loop corrections would be expected to become important.Comment: 13pp, LaTex with Postscript figs, CLNS 93/1202, DART-HEP-93/0

    Expanding Bubbles in a Thermal Background

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    Real scalar field models incorporating asymmetric double well potentials will decay to the state of lowest energy. While the eventual nature of the system can be discerned, the determination of the dynamics of the bubble wall provides many difficulties. In the present study we investigate numerically the evolution of spherically symmetric expanding bubbles coupled to a thermal bath in 3+1 dimensions. A Markovian Langevin equation is employed to describe the interaction between bubble and bath. We find the shape and velocity of the wall to be independent of temperature, yet extremely sensitive to both asymmetry and viscosity.Comment: RevTeX, 9 pages (multicols), 9 figures, submitted to Phys. Rev.

    Strategies and Solutions in eHealth: a Literature Review

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    This study has three purposes: first, to provide a synthetic, up-to-date overview of the main emerging strategies for the health care sector in the Western developed countries; second, to understand the possible role of eHealth solutions in each of these emerging strategies; third, to understand how these emerging health care strategies and emerging eHealth solutions may be usefully applied to address one of the most important challenges for health care systems, i.e. population ageing. The overview on emerging strategies and emerging eHealth solutions provided here is based on a literature review including a wide spectrum of recent documents published on the Web about health care and eHealth. The outcome of this document search is a concept matrix linking emerging health care strategies and emerging eHealth solutions. This concept matrix is used as a framework to synthetically describe how eHealth initiatives are perceived by different stakeholders, such as investors, policy makers, insurance companies, PA bodies, researchers and academics, health care professionals, patients
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