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The modelling of industrial systems is a very hard task because of both the number and diversity of parameters to take into account, and the complex relations between these parameters. In this paper, we are interested on the study of a fully automated Integrated Circuit (IC) semiconductor manufacturing plant (lab). In the semiconductor literature, lab behaviour analysis has very often been performed using discrete-event simulation models, but little work has been devoted to the conceptualisation of the modelling approach. Other works focus on the analysis of single parts of the lab, by simplifying the relations between its components. In such a context, the aim of this paper is to use formal methodologies to model all the components of a wafer lab, that is, its physical and control systems, as well as the fabrication process. This model specification can then be used to build a simulation model for the dynamic factory behaviour analysis. [ABSTRACT FROM AUTHOR]

In this paper, the hydrodynamic characteristics of stirred tanks equipped with a mono and double screws with both classic and modified profiles have been numerically investigated. The computer simulations are conducted within a computational fluid dynamic (CFD) code, based on resolution of the Navier-Stokes equations with a finite volume discretization. The numerical results showed that the velocity field is more efficient with the modified screw profile than the one with a simple profile. In the case of the double screw, the importance of viscous dissipation and pumping has been assessed. Also, the pumping and the energetic efficiency reach the highest values. The good agreement between the numerical results and the experimental data confirm the validity of the analysis method. [ABSTRACT FROM AUTHOR]