measurements of the so called ¿mixing time¿ which is related to the applied methods of measurement and the special - sign of the test equipment itself. The cooperation of 17 research groups was stimulated by improved modern methods for experimental research and visualization, for simulations and nume- cal calculations of mixing and chemical reactions in micro and macro scale of time and local coordinates. The research work was financed for a six years period within the recently finished Priority Program of the German Research Foundation (DFG) named ¿Analysis, modeling and numerical prediction of flow- mixig with and without chemical reactions (SPP 1141)¿. The objective of the investigations was to improve the prediction of efficiencies and selectivities of chemical re- tions on macroscopic scale.