Influence of electric fields over the nucleation ratio of the lithium-potassium sulfate and its pedagogical value

[EN]This paper presents our research about nucleation and its dependency with external conditions, as well as the internal characteristics of the solution itself. Among the research lines of our group, we has been studying the influence of electric fields over two different but related compounds: Lithium-Potassium Sulfate and Lithium-Amonium Sulfate, which both of them show a variation on the nucleation ratio when an electric field is applied during the crystal growth. Moreover, in this paper will be explained a laboratory protocol to teach universitary Science students the nucleation process itself and how it depends on external applied conditions, e.g. electric fields.

Three-dimensional simulation of wind fields and air pollution over complex terrain

[EN]In this talk we introduce a new methodology for wind field simulation or forecasting over complex terrain. The idea is to use wind measurements or predictions of the HARMONIE mesoscale model as the input data for an adaptive finite element mass consistent wind model [1,2]. The method has been recently implemented in the freely-available Wind3D code [3]. A description of the HARMONIE Non-Hydrostatic Dynamics can be found in [4]. The results of HARMONIE (obtained with a maximum resolution about 1 Km) are refined by the finite element model in a local scale (about a few meters). An interface between both models is implemented such that the initial wind field approximation is obtained by a suitable interpolation of the HARMONIE results…

Optical flow estimation with consistent spatio-temporal coherence models

[EN] In this work we propose a new variational model for the consistent estimation of motion fields. The aim of this work is to develop appropriate spatio-temporal coherence models. In this sense, we propose two main contributions: a nonlinear flow constancy assumption, similar in spirit to the nonlinear brightness constancy assumption, which conveniently relates flow fields at different time instants; and a nonlinear temporal regularization scheme, which complements the spatial regularization and can cope with piecewise continuous motion fields. These contributions pose a congruent variational model since all the energy terms, except the spatial regularization, are based on nonlinear warpings of the flow field. This model is more general than its spatial counterpart, provides more accurate solutions and preserves the continuity of optical flows in time. In the experimental results, we show that the method attains better results and, in particular, it considerably improves the accuracy in the presence of large displacements.