Model-Based Process Development

Understanding the dependence of film structure and morphology on system layout and process parameters is a core topic for the further development of ZnO technology. Work is being performed on in situ characterization of deposition processes. Growth processes are simulated using Direct Simulation Monte-Carlo (DSMC) techniques to simulate the gas flow and sputter kinetics simulation and Particle-ln-Cell Monte-Carlo (PICMC) techniques for the plasma simulation [132]. 

Acknowledgements. The work presented here was supported by the German Ministry for Science and Education (BMBF) within the framework of the OSTec project on development of energy-efficient glazing (project No. 13N6520), the ZnO network project (project No. 01SF00314) and the 2+2 project transparent conductive 

Tanaka, H. Ohsaki, Thin Solid Films 502, 223 (2006) 

Ellmer, F. Kudella, R. Mientus, R. Schieck, S. Fiechter, Thin Solid Films 247, 15 (1994) 

Menner, R. Schaffler, B. Sprecher, B. Dimmler, in Proceedings of the 2nd World Conference on Photovoltaic Energy Conversion, Vienna, 1998 

---

Integrated process units and combined unit operations should be linked with advanced process modeling tools, in-line monitoring, model-based process management and advanced process control to form centers of excellence for fast process development. 

To calculate the risk contours with high degree of confidence the models used in a simulation needs to be described in a formal way and would benefit from being standardized [14]. Formalized information models and use cases are also real enablers for model driven or model based software development processes. 

Those based on strictly empirical descriptions Mathematical models based on physical and chemical laws (e.g., mass and energy balances, thermodynamics, chemical reaction kinefics) are frequently employed in optimization apphcations. These models are conceptually attractive because a gener model for any system size can be developed before the system is constructed. On the other hand, an empirical model can be devised that simply correlates input-output data without any physiochemical analysis of the process. For... 

To evaluate the economics of this process, a cost model has been developed to estimate the separation costs for a specific racemate [68, 69]. For this purpose, the sensitivity of the separation costs for several key process parameters have been established as compared to a base-case separation in which a purity of 99 % is required at an enantioselectivity of 1.15. The maximum solubility of the drug is set... 

The pitfalls of a computer model are obvious in that it is only a conceptual representation of the reactor and includes only as many aspects of the real reactor as present knowledge permits. In addition, even the most perfectly conceived description will still depend upon the accuracy of the physically measured constants used in the model for the quality of the process representation. The goal of this report is, however, only to show conceptual trends and the technological base is developed to the extent that the conceptual trends will be correct. In some respects the computer model is a better process development tool than the pilot plant used for the LDPE process since the pilot reactor does not yield directly scaleable information. The reader should take care to direct his attention to the trend information and conceptual differences developed in this work very little attention should be paid to the absolute values of the parameters given. 

The globally S5mchronous development of erosion surfaces and slow uplift rates of shields indicates that models based on localized heating of the crust and mantle are not adequate to explain the uplift process. To produce near simultaneous surfaces on separate continents. King (1967) invoked global epeirogeny - uplift... 

In order to design a zeoHte membrane-based process a good model description of the multicomponent mass transport properties is required. Moreover, this will reduce the amount of practical work required in the development of zeolite membranes and MRs. Concerning intracrystaUine mass transport, a decent continuum approach is available within a Maxwell-Stefan framework for mass transport [98-100]. The well-defined geometry of zeoHtes, however, gives rise to microscopic effects, like specific adsorption sites and nonisotropic diffusion, which become manifested at the macroscale. It remains challenging to incorporate these microscopic effects into a generalized model and to obtain an accurate multicomponent prediction of a real membrane. 

---