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Several nanomaterials have been currently developed and new applications has became possible due to the special materials performance requirements. The TiO2nanoparticles are of special interest due to the wide range of applications from cosmetics to paint and new applications have continuously been searched. However, the effect of these particles into the environment need detailed investigation since some deleterious effects on the ecosystems have been observed. This paper deals with the mechanism of nanoparticles absorption/desorption by soil landfills. A long term simulation of the nanoparticles motion and contamination plume is carried out in the Volta Redonda Municipal Waste landfill and main transport parameters are determined. The model is used to predict the concentration of TiO2nanoparticles in suspension on the leachate of Municipal Waste landfills and the rate of particles dynamically attached into the soil particles

El objetivo del trabajo fue desarrollar un modelo matemático capaz de simular el proceso convencional de colada continua de aceros IF (Interstitial Free), y determinar las condiciones operacionales óptimas. La formulación del modelo incluye las ecuaciones de momento lineal de materiales líquidos y solidificados junto con la evolución térmica de la plancha. Las ecuaciones diferenciales y las condiciones de contorno son resueltas numéricamente mediante volúmenes finitos. Ciertas condiciones de contorno como el flujo de calor para el enfriamiento en cada región, además de la resistencia al flujo de la capa de fundente y las oscilaciones en la región del molde, son especificadas. Las predicciones del modelo fueron comparadas con datos industriales para las condiciones de las coladas continuas convencionales y extendidas a aceros IF. Palabras clave: colada continua, acero IF, modelado matemático, simulación computacional, volúmenes finitos. Modeling of the conventional process of continuous Interstitial Free casting AbstractThe purpose of this work was to develop a mathematical model able to simulate the continuous casting process of IF steel (Interstitial Free).and to determine the optimum operating conditions. The model formulation involves the momentum equations of liquid and solidified materials coupled with the temperature evolution of the slab. The differential equations and boundary conditions are numerically solved using the finite volume technique with appropriated boundary conditions for each region of the casting machine. The model predictions were compared with industrial data for conventional continuous casting conditions and extended to IF steel.

This chapter describes the numerical simulations of a coupled industrial scale of the tundish and continuous casting process. The governing equations are presented, and the numerical procedure is discussed in a common framework. The coupled solutions are presented for the transient turbulent flows within the tundish, solidifying zone and extracting regions with the coupling phenomena of heat and mass transfer. The tundish region flow and refractory are calculated using the inlet and outlet boundary conditions in order to estimate the filling phenomena. The transitions and cooling zones for the thin slab continuous casting process are designed to account for the control of the solidified skin in order to avoid breakout. We compared the numerical predictions of the temperatures with industrial monitoring data for a reference case in order to verify the consistence of the model predictions. A parallel version of the numerical code is proposed aiming to improve the computation time keeping numerical accuracy.