Resumen: We consider the Elrod-Adams model extending the classical lubrication Reynolds equation to the case of the possible presence of a cavitation region. We show that the behaviour of the pressure and saturation depends crucially on the behaviour of the separation h (t, x, y) among the two surfaces. In particular, we exhibit some simple formulations for which we prove (rigorously) that
a cavitation region is formed instantaneously (even for initially saturated flows). Some numerical experiences are also given.
Resumen: Trabajo que analiza, fundamentalmente, las comunicaciones diplomáticas españolas durante los importantes años posteriores a la Guerra de la Independencia. España dejó de ser una gran potencia para convertirse en una potencia media, clasificación que ya nunca abandonaría. La importancia de estos años, en las relaciones exteriores occidentales, es enorme, un nuevo sistema internacional se estaba gestando y es interesante la actitud
española ante estos cambios.
Palabras clave: Diplomacia española, Congreso de Viena, Congreso de Aquisgrán, Fernando VII, Pedro Gómez Labrador, Garcia de León y Pizarro, Acta de Viena, Tratado de Valençay, Tratado Adams-Onís, la Restauración, Sistema internacional posnapoleónico, Relaciones exteriores, España, Siglo XIX
Resumen: We study an evolution free boundary problem issued from hydrodynamic lubrication. The cavitation phenomenon takes place and is described by the Elrod-Adams model. This model is suggested in preference to the classical variational inequality due to its ability to describe input and output flow. The considered model is governed by the parabolic Reynolds equation and the unknows are the
pressure of the lubricant contained in the narrow gap between two circular cylinders and its percentage in an elementary volume.
The main result of this paper is the uniqueness of the solution for the parabolic free boundary problem. The proof of this result is based on a comparison principle permitting compare two solutions of the problem when their initial values and their values on the boundary can be compared. Previously, we state a continuity result and some monotonicity properties of the solution.
