Waste heat energy harvesting by use of BaTiO3 for pyroelectric hydrogen generation

The generation of hydrogen as a chemical energy storage for power generation via fuel cells or for the synthesis of fuels has attained a strong interest in recent years. By way of example this is realized using electrolysis of water with the help of excess electricity of wind power plants. However with low temperature grade waste heat as it could be found in many industrial and household applications, there is another source of usable energy for this purpose. In a first pragmatic experimentation we investigated the pyroelectric effect of ferroelectric BaTiO3 combined with a temperature cycling to generate hydrogen from water. Therefore, single crystals ground to powder were brought into contact with distilled water and set to a cyclical temperature change from 40 °C to 70 °C. With the help of a highly selective and sensitive measuring system based on a coulometric solid electrolyte detector we could provide a first indication of pyroelectric generated hydrogen by a fraction of 300 Vol.-ppb in the sample gas

Application of rotating magnetic fields to crystal growth under microgravity (experiments on FOTON-M3)

Several doped and alloyed crystals such as Ge-Ga and Ge-Si were processed during the international FOTON-M3 spaceflight mission in September 2007. The growth furnace was equipped with a rotating magnetic field (RMF) with induction and frequency up to 3 mT and 100 Hz, respectively. The main goals of the experiments were to study the influence of the RMF on the crystal growth under microgravity. The first results obtained tinder microgravity are presented and discussed with respect; to the ground reference experiments and numerical simulations

Widespread occurrence of expressed fungal secretory peroxidases in forest soils

Fungal secretory peroxidases mediate fundamental ecological functions in the conversion and degradation of plant biomass. Many of these enzymes have strong oxidizing activities towards aromatic compounds and are involved in the degradation of plant cell wall (lignin) and humus. They comprise three major groups: class II peroxidases (including lignin peroxidase, manganese peroxidase, versatile peroxidase and generic peroxidase), dye-decolorizing peroxidases, and hemethiolate peroxidases (e. g. unspecific/aromatic peroxygenase, chloroperoxidase). Here, we have repeatedly observed a widespread expression of all major peroxidase groups in leaf and needle litter across a range of forest ecosystems (e. g. Fagus, Picea, Acer, Quercus, and Populus spp.), which are widespread in Europe and North America. Manganese peroxidases and unspecific peroxygenases were found expressed in all nine investigated forest sites, and dye-decolorizing peroxidases were observed in five of the nine sites, thereby indicating biological significance of these enzymes for fungal physiology and ecosystem processes. Transcripts of selected secretory peroxidase genes were also analyzed in pure cultures of several litter-decomposing species and other fungi. Using this information, we were able to match, in environmental litter samples, two manganese peroxidase sequences to Mycena galopus and Mycena epipterygia and one unspecific peroxygenase transcript to Mycena galopus, suggesting an important role of this litter-and coarse woody debris-dwelling genus in the disintegration and transformation of litter aromatics and organic matter formation