8,876 research outputs found
Shallow-water brittle-star (Echinodermata: Ophiuroidea) assemblages from the Aptian (Early Cretaceous) of the North Atlantic:first insights into bathymetric distribution patterns
Global well-posedness for passively transported nonlinear moisture dynamics with phase changes
We study a moisture model for warm clouds that has been used by Klein and
Majda as a basis for multiscale asymptotic expansions for deep convective
phenomena. These moisture balance equations correspond to a bulk microphysics
closure in the spirit of Kessler and of Grabowski and Smolarkiewicz, in which
water is present in the gaseous state as water vapor and in the liquid phase as
cloud water and rain water. It thereby contains closures for the phase changes
condensation and evaporation, as well as the processes of autoconversion of
cloud water into rainwater and the collection of cloud water by the falling
rain droplets. Phase changes are associated with enormous amounts of latent
heat and therefore provide a strong coupling to the thermodynamic equation.
In this work we assume the velocity field to be given and prove rigorously
the global existence and uniqueness of uniformly bounded solutions of the
moisture model with viscosity, diffusion and heat conduction. To guarantee
local well-posedness we first need to establish local existence results for
linear parabolic equations, subject to the Robin boundary conditions on the
cylindric type of domains under consideration. We then derive a priori
estimates, for proving the maximum principle, using the Stampacchia method, as
well as the iterative method by Alikakos to obtain uniform boundedness. The
evaporation term is of power law type, with an exponent in general less or
equal to one and therefore making the proof of uniqueness more challenging.
However, these difficulties can be circumvented by introducing new unknowns,
which satisfy the required cancellation and monotonicity properties in the
source terms
An integrated risk estimation methodology: Ship specific incident type risk
Shipping activity has increased worldwide, including parts of Australia, and maritime administrations are trying to gain a better understanding of total risk exposure in order to mitigate risk. Total risk exposure integrates risk at the individual ship level, risk due to vessel traffic densities, physical environmental criteria, and environmental sensitivities. A comprehensive and robust risk exposure metric can be beneficial to maritime administrations to enhance mitigation of potential harm and reduce vulnerability to the marine environment as well as to safeguard lives and property. This report outlines an integrated methodology to estimate total risk exposure, with specific attention for the ship specific risk for different types of incident. Some related application aspects of the models are discussed
Kurze Geschichte des UniversitĂ€tsarchivs MĂŒnster:Vortrag anlĂ€sslich des Festaktes zum 100-jĂ€hrigen JubilĂ€um des UniversitĂ€tsarchivs MĂŒnster am 5. September 2012
Der Vortrag behandelt im Ăberblick die Geschichte des UniversitĂ€tsarchivs MĂŒnster von seiner Entstehung durch Senatsbeschluss vom 12. Juni 1912 bis in die Gegenwart. Die verschiedenen UniversitĂ€tsarchivare und GeschĂ€ftsfĂŒhrer sowie ihr Wirken fĂŒr das Archiv werden vorgestellt. Neben der personellen Ausstattung ist die rĂ€umliche Unterbringung, nicht zuletzt vor dem Hintergrund der Kriegseinwirkungen, ein wichtiger Gesichtspunkt. Daneben werden die BestandsgröĂe, die rechtlichen Grundlagen, die mit dem Archiv befassten Gremien, die Beziehungen zu den anderen UniversitĂ€tseinrichtungen und den ĂŒbrigen Archiven MĂŒnsters sowie die derzeitige Situation und aktuelle Entwicklungen thematisiert
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