Influence of mechanical activation and fluorine ion on forsterite formation

The influence of mechanical activation of the mixture basic MgCO3-amorphous SiO2 on reaction of forsterite formation was studied with and without the presence of fluorine ion. Beneficial influence of mechanical activation on the reaction in the mixture without fluorine ion is a consequence of the change of the granulometry during the intense milling. Mechanical activation in the presence of fluorine ion affects the mechanism of forsterite formation via different compounds from the humite group. With non-activated mixture dominant transition phase is hondrodite, while with activated mixture, clinohumite is the transition compound in the process of formation of end reaction products. Fluorine ion is released from the system by hydrolysis. (C) 2001 Elsevier Science S.A. All rights reserved

Self-propagating room temperature synthesis of nanopowders for solid oxide fuel cells (SOFC)

Ceria based solid solutions are promising ceramic electrolytes for SOFC which will be able to function at intermediate temperatures. In accordance with common trends to decrease the production and operating costs of new generation of SOFC materials the reaction based on metathetical pathway is described, whereby solid solution powders of rare earth doped ceria in the nanoscale range were obtained at room temperature. By simple hand mixing of reactants the reaction was enhanced, propagating afterwards by itself. Nanometric ceria powders doped with Y or Nd, as well as co doped with both cations were synthesized. Composition of Ce1-xMexO2-y ranged from x =0-0.25. The reaction course is described in detail and the properties of the obtained powders are presented. (c) 2005 Elsevier B.V. All rights reserved.Meeting on Fuel Cells Science and Technology, Oct 06-07, 2004, Munich, German

The Bosna River floods in May 2014

In May 2014, extreme floods occurred in the lower Sava River basin, causing major damage, with catastrophic consequences. Based on the data gathered, the weather situation in Bosnia and Herzegovina's (BiH) Bosna River basin was analysed and the hydrological conditions were provided, including the results of the probability analysis of the size of the recorded precipitation and flow rates. According to the observed data, extremely high precipitation intensities produced specific discharges of 1.0 m3 s−1 km−2. A hydrological model of the Bosna River basin was developed using HBV light for the purposes of reconstructing and forecasting such events more effectively. All analyses confirmed that the May 2014 event was an extreme extraordinary event whose return period greatly exceeds 100 years. The study is the basis for further flood safety measures and flood forecast development in the Bosna River basin