1 CONTROL OVER NANO-CRYSTALIZATION IN TURBULENT FLOW IN THE PRESENCE OF MAGNETIC FIELDS S. Kobe, G. Dražić, P. J. McGuiness, T. Meden Jozef Stefan Institute, Jamova 39, 1001 Ljubljana, Slovenia. E. Sarantopoulou, Z. Kollia, A. C. Cefalas National Hellenic Research Foundation, TPCI, 48 Vassileos Constantinou Ave. Athens 11635, Greece. Abstract The influence of the magnetic field and the water flow on the crystal form of calcium carbonate precipitated from low-concentration water solution was followed systematically. By changing the strength of the field the calcite/aragonite/vaterite ratio varied. The crystal form and the particle size distribution of the precipitated calcium carbonate were determined by using X-ray analyses and TEM. A simple hydro dynamical model, using the Navier-Stoke’s and Maxwell’s equations predicts that there is a strong energy coupling and transfer between turbulent flow and the magnetic fields and they can be amplified to high values. Since the formation of aragonite is enhanced in the presence of magnetic field, scaling is prevented in turbulent flow. Index Terms — scaling, magnetic water treatment, magneto hydrodynamics, turbulent flow. 1. Introduction The formation of calcium carbonate is not only a common ionic reaction that takes place in natural processes, it also results in a problem known as scaling, which is present in our everyday lives and in various industrial processes and technologies. In spite of the reaction’s simplicity there is a considerable variability in the properties of the solid product, such as crystal form, particle size distribution, electro- kinetics potential, etc. Magnetic treatment of water for scaling control and prevention represents one of the most promising water treatment technologies today. The promise of this technology lies mostly in its ecological importance and relatively low cost of its implementation and maintenance, in comparison with