Search results for "boundary"

showing 10 items of 1626 documents

Simulation of the Propagation of Tsunamis in Coastal Regions by a Two-Dimensional Non-Hydrostatic Shallow Water Solver

2017

Due to the enormous damages and losses of human lives in the inundated regions, the simulation of the propagation of tsunamis in coastal areas has received an increasing interest of the researchers. We present a 2D depth-integrated, non- hydrostatic shallow waters solver to simulate the propagation of tsunamis, solitary waves and surges in coastal regions. We write the governing continuity and momentum equations in conservative form and discretize the domain with unstructured triangular Generalized Delaunay meshes. We apply a fractional- time-step procedure, where two problems (steps) are consecutively solved. In the first and in the second step, we hypothesize a hydrostatic and a non-hydro…

TurbulenceVoronoi cellShallow waters; Non-hydrostatic pressure; Unstructured mesh; Wetting/drying; Tsunami propagation; Long waves; Voronoi cells; Runge-Kutta method; Galerkin scheme; Manning equation; Dirichlet condition; OpenFOAMShallow waterLong waveUnstructured meshGeophysicsSolverTsunami propagationSettore ICAR/01 - IdraulicaThermal hydraulicsWetting/dryingWaves and shallow waterBoundary layerNon-hydrostatic pressureDirichlet conditionFluid dynamicsRunge-Kutta methodOpenFOAMMagnetohydrodynamicsNavier–Stokes equationsGalerkin schemeGeologyManning equation
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Ultrasonic guided wave propagation in long bones with varying cortical thickness

2009

The propagation of ultrasonic guided wave (GW) in the long bone is very sensitive to the bones' shapes, properties and cortical thicknesses (CTh). Most of the previous studies on the GW propagation in long bones mainly focused on the bones with uniform CTh. However, it is necessary to understand the impacts of CTh variation, such as mode conversion. Therefore, an adequate analysis on GW propagating in long bones with varying CTh is essential for the precise calibration of the quantitative measurement of it. The aim of this study is to use a modified boundary element method (BEM) to analyze the GW propagation characteristics in long bones with varying CTh. Numerical analysis implemented by t…

Ultrasonic guided waveOpticsMaterials sciencebusiness.industryBioacousticsAcousticsNumerical analysisCalibrationSensitivity (control systems)Transmission coefficientbusinessBoundary element methodCutoff frequency2009 IEEE International Ultrasonics Symposium
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Tethyan vs. Cordilleran ophiolites: a reappraisal of distintctive tectono-magmatic features of supra-subduction complexes in relation to the subducti…

2004

Abstract Supra-subduction zone (SSZ) ophiolites deserve special attention because they represent fundamental markers of intraoceanic convergence and generation of new lithosphere above subduction zones. Moreover, owing to their structural characteristics and location in the overriding plate, these complexes are far better represented and preserved than Mid-Ocean-Ridge-Basalt (MORB) ophiolites in orogenic belts. In terms of their structure, tectonics, and magmatic features, SSZ ophiolites may be classified in two main types: (1) “Tethyan complexes” (such as those of the Albanide-Hellenide belt), which mostly consist of complete and extensive volcanic, dyke, plutonic, and mantle sections with…

UnderplatingSubductionEarth scienceGeochemistryOphioliteGeophysicsBack-arc basinIsland arcConvergent boundaryForearcTethyan Cordilleran Suprasubduction zone ophiolites Subduction mode Tectono-magmatic modelsGeologyEarth-Surface ProcessesTerrane
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Crystal-Plastic Deformation, Recovery and Recrystallisation of Quartz

2009

As stated in the introduction, this chapter is included because of the special importance of quartz to estimate metamorphic conditions during and after mylonitisation. The theory behind crystal-plastic deformation is treated elsewhere (e.g. Passchier & Trouw 2005). The main optical expression of crystal-plastic deformation is smooth, non-patchy undulose extinction. Elongated grains with such undulose extinction, sometimes accompanied by deformation lamellae, are indicative for low-temperature deformation. At slightly higher temperatures recovery produces subgrains and recrystallisation tends to substitute the old deformed grains by small new ones. Three types of recrystallisation can be dis…

Undulose extinctionCrystalMaterials scienceMetamorphic rockBoundary migrationComposite materialDeformation (engineering)Quartz
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High-Grade Mylonites

2009

High-grade mylonites are formed at temperatures above 650 °C. They are relatively uncommon, probably because their conservation is problematic. Most mylonites formed under these conditions would tend to fully recrystallise which destroys and masks the mylonitic structure. Mylonitic features are only preserved if grain growth is somehow inhibited in the rock, e.g. by its polymineralic nature.

Undulose extinctionGrain growthGeochemistryBoundary migrationGeologyMylonite
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Quasihyperbolic boundary conditions and capacity: Uniform continuity of quasiconformal mappings

2005

We prove that quasiconformal maps onto domains which satisfy a suitable growth condition on the quasihyperbolic metric are uniformly continuous when the source domain is equipped with the internal metric. The obtained modulus of continuity and the growth assumption on the quasihyperbolic metric are shown to be essentially sharp. As a tool, we prove a new capacity estimate.

Uniform continuityPartial differential equationMathematics::Complex VariablesGeneral MathematicsMathematical analysisMetric (mathematics)Mathematics::Metric GeometryBoundary value problemAnalysisModulus of continuityDomain (mathematical analysis)MathematicsJournal d'Analyse Mathématique
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Decay estimates in the supremum norm for the solutions to a nonlinear evolution equation

2014

We study the asymptotic behaviour, as t → ∞, of the solutions to the nonlinear evolution equationwhere ΔpNu = Δu + (p−2) (D2u(Du/∣Du∣)) · (Du/∣Du∣) is the normalized p-Laplace equation and p ≥ 2. We show that if u(x,t) is a viscosity solution to the above equation in a cylinder Ω × (0, ∞) with time-independent lateral boundary values, then it converges to the unique stationary solution h as t → ∞. Moreover, we provide an estimate for the decay rate of maxx∈Ω∣u(x,t) − h(x)∣.

Uniform normGeneral MathematicsMathematical analysista111CylinderViscosity solutionNonlinear evolutionStationary solutionnonlinear evolution equationBoundary valuesMathematicsProceedings of the Royal Society of Edinburgh, Section: A Mathematics
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Resonant neumann equations with indefinite linear part

2015

We consider aseminonlinear Neumann problem driven by the $p$-Laplacian plus an indefinite and unbounded potential. The reaction of the problem is resonant at $\pm \infty$ with respect to the higher parts of the spectrum. Using critical point theory, truncation and perturbation techniques, Morse theory and the reduction method, we prove two multiplicity theorems. One produces three nontrivial smooth solutions and the second four nontrivial smooth solutions.

Unique continuation propertyReduction methodApplied MathematicsMathematical analysisMultiple solutionPerturbation (astronomy)AnalysiMultiplicity (mathematics)Neumann boundary conditionResonant equationAnalysisCritical groupMathematicsMorse theory
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Boundary blow-up under Sobolev mappings

2014

We prove that for mappings $W^{1,n}(B^n, \R^n),$ continuous up to the boundary, with modulus of continuity satisfying certain divergence condition, the image of the boundary of the unit ball has zero $n$-Hausdorff measure. For H\"older continuous mappings we also prove an essentially sharp generalized Hausdorff dimension estimate.

Unit spherePure mathematicsSobolev mappingBoundary (topology)01 natural sciencesMeasure (mathematics)Hausdorff measureModulus of continuitymodulus of continuity0103 physical sciencesClassical Analysis and ODEs (math.CA)FOS: Mathematics46E35Hausdorff measure0101 mathematicsMathematicsNumerical AnalysisApplied Mathematicsta111010102 general mathematicsZero (complex analysis)Sobolev spaceMathematics - Classical Analysis and ODEsHausdorff dimension010307 mathematical physics26B10Analysis26B35Analysis & PDE
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Solutions to the 1-harmonic flow with values into a hyper-octant of the N-sphere

2013

Abstract We announce existence results for the 1-harmonic flow from a domain of R m into the first hyper-octant of the N -dimensional unit sphere, under homogeneous Neumann boundary conditions. The arguments rely on a notion of “geodesic representative” of a BV-vector field on its jump set.

Unit spheren-sphereGeodesicApplied MathematicsMathematical analysisA domainharmonic flowsOctant (solid geometry)non-convex variational problems1-harmonic flowlower semi-continuity and relaxation; total variation flow; 1-harmonic flow; non-convex variational problems; image processing; geodesic; partial differential equations; harmonic flowsimage processingHomogeneoustotal variation flowNeumann boundary conditionJumppartial differential equationslower semi-continuity and relaxationgeodesicMathematics
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