Fraunhofer reactions

Many manufacturers, e.g. Cellular Process Chemistry, CPC GmbH, Mainz, Microglas Chemtec, Mainz, Ehrfeld Mikrotechnik and the Fraunhofer initiative FAMOS [17-22], are currently working on miniaturized reaction systems. Most of these systems are available on the market or can be purchased on request Common to all is the endeavor to provide complete systems equipped with a chemical environment which allows one to perform certain chemical reactions without any additional equipment. Changeable parts and optional deliverable equipment open up a way to have a flexible chemical laboratory on the desk. Each manufacturer addresses different customers, i.e. chemical research, pharmaceutical drug synthesis or education. 

Reactor 13 [R 13] Modular Micro Reaction System FAMOS (Fraunhofer-Allianz Modulares Mikroreaktionssystem)... 

The Fraunhofer Alliance Modular Microreaction System (FAMOS) is currently working on a micro reaction simulation toolkit (Figure 4.82) with special attention to micro-scale phenomena [124], The virtual toolkit comes with a physical micro reaction toolkit. The MicroSim software reflects the process by considering reaction conditions and reactor geometries. Of course, this approach on the other hand limits the software to the dimensions and geometries of the reactors supplied with the physical toolkit. 

Figure 4.82 Modular micro reaction system of the Fraunhofer Alliance and software process simulation toolkit [124] (by courtesy of FhG-Allianz FAMOS).

In this sense, the solar data in Table 1 represent the modem normality. However, there a few, but highly spectacular, deviant stars. Red stars [112] of spectral class S (T close to 3000 K) show absorption bands of the diatomic molecule ZrO (the far more frequent class M at the same T shows TiO absorption bands) and may also show spectral lines of atoms of teehnetium (Z = 43), of which no isotope is known to have t yj above 2.6 million years, and a quite conspicuous [46, 58] group is Ap stars (peculiar stars of class A), constituting about 5 percent of stars with T in a narrow interval close to 10000 K. The first one to be discovered was the star of third magnitude (with the ancient name Cor Caroli after the British king Charles II, a benefactor of the Greenwich Observatory) Canum Venaticorum, where Baxandall in 1913 detected strong Eu Fraunhofer lines of europium (We are not aware of any reaction to this from the 81-year old Crookes). 

A better approach is given by the numerical calculation models. Detonation codes have been developed at the Research Center Karlsruhe, DETID and D3D, to determine the characteristic parameters within the reaction zone and outside in the unbumt mixture [20, 95, 100]. These models consider a homogeneous mixture of H2, O2, N2, H2O and are mainly applied to examine the load on a nuclear reactor containment. Validation was made against the above mentioned balloon tests of the Fraunhofer Institute and the Russian RUT experiments. Parameter calculations of 3D detonation have shown that the 3D structure is unimportant for the pressure load and that a relatively coarse grid provides sufficient accuracy [20]. 

Figure 7.14 Photograph of the microstructured falling film plates [52]. Insets show the structure in detail, (a) Reaction plate with rhomb structure, (b) Reaction plate with herring bone structure. Courtesy Fraunhofer ICT-IMM, Germany...

The reaction between Si02 and PbO is relevant for PZT films on Si containing substrates like 96% Alumina, Si wafer and LTCC. The existence of silicon oxide in tire substrate and in commercial electrode materials causes the diffusion into the PZT thick film and the reaction to Pb based silicates, which deteriorate ftie ferroelectric behavior of the PZT thick film. Therefore a special Au electrode was developed by Fraunhofer KTS with modified composition preventing silicate formation during firing of the PZT thick film. For ZtOr and AI2O3 substrates a commercial Au electrode (Heraeus 5789) fired at 850°C/ 30 min can bee used. 

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