116 research outputs found
Moments conservation in adaptive Vlasov solver
We previously developed an adaptive semi-Lagrangian solver using a multiresolution analysis based on interpolets which are a kind of interpolating wavelets introduced by Deslauriers and Dubuc. This paper introduces a new multiresolution approximation for this solver which allows to conserve moments up to any order by using the lifting method introduced by Sweldens
Adaptive 2-D Vlasov Simulation of Particle Beams
International audienceThis paper presents our progress for the solution of the 4D Vlasov equation on a grid of the phase space, using two adaptive methods. We briefly recall the principle of the two methods and then particularly focus on computer science features - as data structures or parallelization - for the efficient implementation of the methods. Some relevant numerical results are presented
Galerkin discontinuous approximation of the MHD equations
International audienceIn this report, we address several aspects of the approximation of the MHD equations by a Galerkin Discontinuous finite volume schemes. This work has been initiated during a CEMRACS project in july and august 2008 in Luminy. The project was entitled GADMHD (for GAlerkin Discontinuous approximation for the Magneto-Hydro-Dynamics). It has been supported by the INRIA CALVI project
Stratigraphy, facies and geodynamic settings of Jurassic formations in the BĂŒkk Mountains, North Hungary: its relations with the other areas of the Neotethyan realm.
Jurassic mélange complexes related to the subduction of the Neotethys Ocean occur
in the BĂŒkk Mountains, North Hungary. This paper characterizes the sedimentary sequence of
basin and slope facies that occur in the southwestern part of the BĂŒkk Mountains, placing special
emphasis on the redeposited sedimentary rocks (olistostromes, olistoliths: Mónosbél Group) in order
to obtain information on the provenance of the clasts, and the mode and time of their redeposition.
The series of formations studied shows a general coarsening-upwards trend. Based on radiolarians
and foraminifera, the Mónosbél Group formed in Early to Late Bathonian time. The lower part
of the complex is typified by a predominance of pelagic carbonates, shale and radiolarite with
andesitic volcaniclastic intercalations. The higher part of the succession is characterized by polymictic
olistostromes. Large olistoliths that are predominantly blocks of Bathonian shallow marine limestone
(BĂŒkkzsĂ©rc Limestone) appear in the upper part of the sequence. Based on the biostratigraphic and
sedimentological data, results of analyses of the redeposited clasts and taking into consideration
the concepts of the development of the western Neotethys domain, the evolutionary stages of the
sedimentary basins were defined. The onset of the compressional stage led to initiation of nappe
stacking that led to the formation of polymict olistostromes and then to the redeposition of large
blocks derived from out-of-sequence nappes of the former platform foreland
Cambrian-Eocene pre-rift, pulsed rift, passive margin and emplacement processes along the northern margin of the Southern Neotethys: evidence from the Antalya Complex in the Alanya Window (S Turkey)
Sedimentary rocks in the Alanya Window document pulsed Permian-Triassic rifting in a proximal basin setting, adjacent to the Tauride continental unit (Geyik DaÄ). Late Cambrian-Early Ordovician clastic sediments accumulated along the north margin of Gondwana on a variable shallow-marine shelf. Above an unconformity related to rift-shoulder uplift, Late Permian facies document shallow-marine to evaporitic environments during regional tectonic subsidence (first main rift pulse). Above a second unconformity (both extension and sea-level controlled), Early Triassic carbonates and mudrocks accumulated on an unstable, gently subsiding shelf. Mudrocks, sandstones and lithoclastic debris-flows, derived from the underlying succession, accumulated during the Middle Triassic (Anisian-early Ladinian), implying strong tectonic subsidence and flank uplift (second main rift pulse). Radiolarian mudstones accumulated during late Middle Triassic-early Late Triassic in a well-oxidised, organically productive, but relatively quiescent, deep-water basin above the carbonate compensation depth (CCD). Thick (100s m) lithoclastic sandstone turbidites (commonly plant-rich) and localised debris-flows accumulated during the Late Triassic (Carnian), together with detached blocks of underlying lithologies (third main rift pulse, with regional uplift). Alkaline basaltic sills were intruded locally. Final continental break-up to create the Southern Neotethys took place regionally during the Late Triassic (Carnian). Latest Triassic-Late Cretaceous deposition records passive margin subsidence. Variable low-grade metamorphism and two-stage tectonic emplacement (southwards(?) then northwards) took place during latest Cretaceous and Eocene, respectively. The tectonic-sedimentary development of the Antalya Complex provides insights into rift/continental break-up processes that differ from the recently well-documented Alpine-North Atlantic region.Publisher PDFPeer reviewe
Vlasov simulations on an adaptive phase-space grid
The numerical resolution of the Vlasov equation is usually performedby particle methods (PIC) which consist in approximating the plasma bya finite number of particles. This method allows to obtain satisfying results with a relatively smallnumber of particles. However, it is well known that, in some cases,the numerical noise inherent to the particle method becomes tooimportant to have an accurate description of the distribution functionin phase space. To remedy to thisproblem, methods discretizing the Vlasov equation on a mesh of phasespace have been proposed. The major drawback of Vlasov methods using a uniform and fixed mesh is thattheir numerical cost is high, which makes them rather inefficient whenthe dimension of phase-space grows. For this reason we areinvestigating a method using an adaptive mesh. The adaptivemethod is overlayed to a classical semi-Lagrangian method which isbased on the conservation of the distribution function alongparticle trajectories. The phase-space grid is updated using amultiresolution technique based on interpolating wavelets
New insights on the Antalya Nappes in the apex of the Isparta Angle: the Isparta Ăay unit revisited
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