A mathematical model of the galvanic iron corrosion is, here, presented. The iron(III)-hydroxide formation is considered together with the redox reaction. The PDE system, assembled on the basis of the fundamental holding electro-chemistry laws, is numerically solved by a locally refined FD method. For verification purpose we have assembled an experimental galvanic cell; in the present work, we report two tests cases, with acidic and neutral electrolitical solution, where the computed electric potential compares well with the measured experimental one

About 50 % of the glaciated area outside the large ice sheets is located in the Arctic, and they contribute about 30 % to the runoff. IPCC predicts that the largest contribution to global sea level rise will stem from glaciers and ice caps. However, the uncertainties are large, up to 50%. Present estimates of mass balance of Svalbard glaciers are scarce and vary from close to balance to significantly negative. The dynamic response of the glaciers varies on the different glacier types: 1) Ice caps 2) tidewater glaciers and 3) glaciers ending on land. We are interested in estimating how changes in climate can affect the future mass balance of Svalbard glaciers and, consequently, the contribution to sea-level rise. This will be accomplished through modelling of ice flow, including calving fluxes, supported by field data. The proposed modelling work also includes Regional Climate modelling providing surface mass balance estimates for the whole of Svalbard, surface mass balance modelling for targeted glaciers and sensitivity analysis by different approaches using degree-day and energy balance models as well as couplings to atmosphere, hydrology and dynamics. A warmer climate may change both surface processes (snow accumulation, internal refreezing, superimposed ice and ablation) and dynamics. Predictions of future mass balance and dynamic response require boundary information about the thermal structure of the ice, the present and past surface mass balance, meteorological data/atmospheric field studies (AWS), surface and bed topography and current flow. These points will be the main focus for the field and remote sensing investigations. Remote sensing data is the only way to get enough spatial data, but must be validated by field data. We propose to address the above questions in a set of complementary field, remote sensing and modelling programs.

A mathematical model of the galvanic iron corrosion is, here, presented. The iron(III)-hydroxide formation is considered together with the redox reaction. The PDE system, assembled on the basis of the fundamental holding electro-chemistry laws, is numerically solved by a locally refined FD method. For verification purpose we have assembled an experimental galvanic cell; in the present work, we report two tests cases, with acidic and neutral electrolitical solution, where the computed electric potential compares well with the measured experimental one

Marine phytoplankton is known to produce surface-activity materials as part of its metabolism.

l'attività seminariale è sostenuta dai ricercatori e collaboratori dell'IAC ed è rivolta ai ricercatori dell'area romana, essendo finalizzata alla promozione degli interessi di ricerca coltivati in istituto e alla disseminazione dei risultati conseguiti.

An improvement of a mathematical model of the galvanic iron corrosion, previously presented by one of the authors, is here proposed. The iron(III)-hydroxide formation is, now, considered in addition to the redox reaction. The PDE system, assembled on the basis of the fundamental holding electro-chemistry laws, is numerically solved by a locally refined FD method. For verification purpose we have assembled an experimental galvanic cell; in the present work, we report two tests cases, with acidic and neutral electrolitical solution, where the computed electric potential compares well with the measured experimental one.

We present results of a numerical simulation of the thermal convection in the subsurface mushy ice layer of Europa, one of the Jupiter's moons. Beside fluid dynamics and heat transfer within such a layer, heat conduction in the solid crustal surface and heat exchange between the two phases - mushy ice and solid crust - are included in our model in order to follow also the evolution of the phase front. Since the images of Europa's crust taken by the spacecrafts Voyager and Galileo got to be known, planetary scientists stimulated this kind of investigations with the aim of studying the origin of such a topographic aspect. Actually the chaotic lineaments and splotches, clearly visible, solicited the conjecture of the existence of an internal ocean of water that is also supported by the most recent Galileo magnetic field data. The presence of water would make life possible on the jovian satellite. However, in the recent literature, just few numerical simulations describing the overall scenario and including either heat transfer and convection flow have been proposed. Here we adopt the stream-function/vorticity formulation of the Navier-Stokes equations for the flow of the mushy ice and a Stefan condition combined with a front-fixing technique for the front evolution. Our numerical discretization is based upon an ENO scheme. Mathematical model and numerical procedure have been thoroughly tested and have the advantage of yielding accurate numerical solutions via relatively coarse space discretization grids. For applications in this field the present one is the first attempt, at our knowledge, to solve a complete Stefan condition with convection flow, obtaining a good match with other numerical solutions in the literature.

We present the results of the numerical simulation of the first stages of the melting from a side of a gallium slab by adding to the heat transfer and to the melt flow the description of the effects of the deformations of the solid phase. The experiment by Gau and Viskanta in [4] has been considered.