Complex geodesics in a class of convex bounded Reinhardt domains

We find explicitly all complex geodesics in a class of convex bounded Reinhardt domains ofC ⁿ, which are a generalization of complex ellipsoids. Entrata in Redazione il 19 maggio 1998.     

Two-scale convergence of some integral functionals

Nguetseng’s notion of two-scale convergence is reviewed, and some related properties of integral functionals are derived. The coupling of two-scale convergence with convexity and monotonicity is then investigated, and a two-scale version is provided for compactness by strict convexity. The div-curl lemma of Murat and Tartar is also extended to two-scale convergence, and applications are outlined.     

Study of the Eddy-Current Problem Taking Account of Hall's Effects

AMS(MOS): 35K

The parabolic problem corresponding to Maxwell's equations in a metal conductor is studied taking account of Hall's effect,i.e. the dependence of resistivity of the magnetic field. A variational formulation is given and an existence theorem is proved by using a compactness result based on a strict convexity property.     

Existence results for some free boundary filtration problems

Summary A suitable extension of the pressure junction allows to formulate quite general free boundary filtration problems in terms of a non-standard variational inequality, both for the stationary and the evolution situations. Existence results are proved.

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Sunto Un opportuno prolungamento della funzione pressione permette di formulare problemi di filtrazione a frontiera libera alquanto generali in termini di una disequazione variazionale di tipo non standard. Si dimostrano risultati di esistenza, sia per il caso stazionario che per quello di evoluzione.

     

On hysteresis in elasto-plasticity and in ferromagnetism

We define hysteresis as rate-independent memory, illustrate some of its properties, and review some scalar models of elasto-plasticity: the stop, the play, the Prandtl–Ishlinski models. In particular we study the Prager model of linear kinematic hardening, which encompasses stops and plays. We then couple the latter model with the dynamic equation for a one-dimensional system, show existence of a weak solution, and deal with its homogenization. We also discuss the extension to tensors and to three-dimensional systems.

We then deal with ferromagnetic hysteresis. We review the classic Preisach model and a vector extension. Finally, we formulate a model of vector ferromagnetic hysteresis, couple it with the magnetostatic equations, and discuss its homogenization. The latter consists in a two-length-scale model, and corresponds to a variant of the vector Preisach model.     

Study of double perovskite La2B(II)MnO6 (B: Ni,Co, Cu) as electrode materials for energy storage

Journal of Solid State Electrochemistry - In this paper, the study of the potential capacity of energy storage in supercapacitors containing oxide La2B(II)MnO6 (with B = Cu, Co, Ni) as...     

Ten Issues About Hysteresis

In this note some basic models of hysteresis are reviewed: the linear and generalized plays, the relay and the Preisach model. Some related questions are also illustrated.