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A singular equation with positive and free boundary solutions.

Juan Dávila, Marcelo Montenegro (2003)

RACSAM

Para 0 < β < 1 consideramos la ecuación -Δu = χ{u > 0} (-u-β + λf(x, u)) en Ω­ con condición de borde tipo Dirichlet. Esta ecuación posee una solución maximal uλ ≥ 0 para todo λ > 0. Si λ es menor que una cierta constante λ*, uλ se anula en el interior del dominio creando una frontera libre, y para λ > λ* esta solución es positiva en Ω­ y estable. Establecemos la regularidad de uλ incluso en presencia de una frontera libre. Para λ ≥ λ* la solución del problema...

A stability result in the localization of cavities in a thermic conducting medium

B. Canuto, Edi Rosset, S. Vessella (2002)

ESAIM: Control, Optimisation and Calculus of Variations

We prove a logarithmic stability estimate for a parabolic inverse problem concerning the localization of unknown cavities in a thermic conducting medium Ω in n , n 2 , from a single pair of boundary measurements of temperature and thermal flux.

A stability result in the localization of cavities in a thermic conducting medium

B. Canuto, Edi Rosset, S. Vessella (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We prove a logarithmic stability estimate for a parabolic inverse problem concerning the localization of unknown cavities in a thermic conducting medium Ω in n , n ≥ 2, from a single pair of boundary measurements of temperature and thermal flux.

A stationary flow of fresh and salt groundwater in a heterogeneous coastal aquifer

S. Challal, A. Lyaghfouri (2000)

Bollettino dell'Unione Matematica Italiana

Si stabilisce l'esistenza e l'unicità di una soluzione monotona per il problema di frontiera libera correlato al flusso stazionare d'acqua dolce e salata intorno ad un acquifero eterogeneo. Si provano la continuità e l'esistenza di un limite asintotico della frontiera libera.

A Survey on Mathematical Modelling of Deposition in Waxy Crude Oils

A. Fasano, L. Fusi, S. Correra, M. Margarone (2011)

Mathematical Modelling of Natural Phenomena

Waxy Crude Oils (WCO’s) are characterized by the presence of heavy paraffins in sufficiently large concentrations. They exhibit quite complex thermodynamical and rheological behaviour and present the peculiar property of giving rise to the formation of segregated wax deposits, when temperature falls down the so called WAT, or Wax Appearance Temperature. In extreme cases, segregated waxes may lead to pipeline occlusion due to deposition on cold walls....

Adapting meshes and time-steps for phase change problems

Ricardo H. Nochetto, Alfred Schmidt, Claudio Verdi (1997)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

We address the numerical approximation of the two-phase Stefan problem and discuss an adaptive finite element method based on rigorous a posteriori error estimation and refinement/coarsening. We also investigate how to restrict coarsening for the resulting method to be stable and convergent. We review implementation issues associated with bisection and conclude with simulations of a persistent corner singularity, for which adaptivity is an essential tool.

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