Repositório Colecção: Artigos (Papers)
https://hdl.handle.net/1822/1231
Artigos (Papers)2024-03-29T01:45:06ZOn the solution of the slope beach problem in the context of shallow-water code benchmarking: Why non-linearization of the initial waveforms is essential
https://hdl.handle.net/1822/68849
Título: On the solution of the slope beach problem in the context of shallow-water code benchmarking: Why non-linearization of the initial waveforms is essential
Autor: Figueiredo, Jorge; Clain, Stéphane
Resumo: We detail a new semi-analytic solution for the slope beach problem in which linearization of the initial waveform is not carried out to provide the exact corresponding boundary condition for the transformed problem. Numerical code benchmarking requires the construction of exact solutions to check the convergence order and efficiently compare the simulations using fine meshes. We quantify the impact of the linearization assumption and compare two situations (linearized and non-linearized) with a second-order finite volume code. The accuracy of the shoreline velocity, maximum run-up, and maximum run-down situations, in particular, are of crucial importance in applications as they characterize the inundation and impact intensity of a wave on potential infrastructure. To this end, we provide two sets of spreadsheets, containing highly accurate approximations of the exact non-linearized solution for cases (c) and (d) of Carrier et al. (2003) study, for benchmarking purposes.
Descrição: Supplementary material associated with this article can be found, in the online version, at: 10.1016/j.advwatres.2020.103751 (https://data.mendeley.com/datasets/7by5kxsdk4/draft?a=e3db45dc03e1-4d5b-a0e0-ba7fd533123f)
<b>Tipo</b>: articleAffine collineations in Einstein-Maxwell space-times
https://hdl.handle.net/1822/63956
Título: Affine collineations in Einstein-Maxwell space-times
Autor: Carot, J.; Mas, L.; Rago, H.; Costa, J.
Resumo: The existence of an affine vector field in an Einstein-Maxwell space-time is discussed. We first consider the non-null electromagnetic field case, and show that there are no solutions of the Einstein-Maxwell equations admitting a proper affine collineation. In the case of a null electromagnetic field case, we characterize all the possible solutions with such property.
<b>Tipo</b>: articleOn regular implicit operations
https://hdl.handle.net/1822/10493
Título: On regular implicit operations
Autor: Almeida, Jorge; Azevedo, Assis
<b>Tipo</b>: article2010-03-17T17:06:45ZThe nonlinear problem of two membranes
https://hdl.handle.net/1822/5891
Título: The nonlinear problem of two membranes
Autor: Santos, Lisa
Resumo: The problem of finding the position of two membranes, one constrained by the other, attached to rigid supports, subjected to external forces, is considered. It is proved existence of solution, if we assume a compatibility condition relating the mean curvature of the boundary of the set where the problem is defined and the given data. It is also proved the W^{2,p} regularity of the solution for P greater or equal to 1.
<b>Tipo</b>: article2006-12-12T09:48:37ZThe N-membranes problem for quasilinear degenerate systems
https://hdl.handle.net/1822/2901
Título: The N-membranes problem for quasilinear degenerate systems
Autor: Azevedo, Assis; Rodrigues, José Francisco; Santos, Lisa
Resumo: We study the regularity of the solution of the variational inequality for the problem of N-membranes in equilibrium with a degenerate operator of p-Laplacian type, 1 < p < ∞, for which
we obtain the corresponding Lewy-Stampacchia inequalities. By considering the problem as a system coupled through the characteristic functions of the sets where at least two membranes are in contact, we analyze
the stability of the coincidence sets.
<b>Tipo</b>: article2005-09-14T10:10:02Z