Hiroyasu Sakamura

Electrochemical evaluation of oriented vanadium oxide films deposited by reactive rf magnetron sputtering

Abstract Thin films of crystalline V 2 O 5 were deposited by reactive rf magnetron sputtering from a metallic vanadium target in argon–oxygen gas mixtures at a substrate temperature of 300°C. We found that the orientation direction of V 2 O 5 films could be controlled by changing the oxygen flow ratio. Cyclicvoltammetry measurements for these films revealed that lithium diffused much faster in the a-axis oriented V 2 O 5 film than the b-axis oriented one. The surface morphology of these samples was also observed, however, there was not much difference between them, i.e.; lithium ion diffusion was not dominated by the porosity of the film in this case. We also found that chemical diffusion coefficient of Li along the a-axis of V 2 O 5 was larger than along the b-axis, hence, the lithium ion diffusion in V 2 O 5 film was attributed to the diffusing direction.

Internal friction in three component metaphosphate glasses

Abstract The internal friction of three component metaphosphate glasses in the quasi-binary system MO·P 2 O 5 -M′O·P 2 O 5 was measured as a function of temperature by a free torsional vibration method. The high-temperature peak of these glasses which include the various combinations of the modifying ions M and M′ where M or M′Ca, Sr and Ba appeared unanimously at ≈160°C. The peak height seemed to be dominated by a modifying ion of larger radius. The ionic radius is in the order Ba 2+ > Sr 2+ > Ca 2+ . For the glasses containing the modifying ions, M  Ca, Sr, Ba and M′  Mg, Zn, the internal friction appeared to be governed strongly by the ions which have a lower coordination number and a larger ionic radius. The MgO·P 2 O 5 ZnO·P 2 O 5 glass exhibited a completely different behavior compared with the parent glasses MgO·P 2 O 5 and ZnO·P 2 O 5 .

Inventory Analysis of Composting System for Garbage Discharged from Retail Stores.

The composting of garbage has been expected to reduce the amount of waste disposal in landfills and to improve the efficiency of power generation combined with refuse incinerator. In this study, the composting of garbage discharged from three stores in CO·EOP Tokyo was researched, and the inventories of the composting system and the incinerating system were investigated from the viewpoint of environmental loads such as energy consumption and solid waste.In the results obtained from the composting research, the electricity consumed by the composting of garbage was large in autumn and winter season, and it was ascertained that the electricity consumption was reduced by adjusting the amount of garbage to the capacity of the composting apparatus. The results of the inventory analysis showed that energy consumption in the composting system was larger than that in the incinerating system. The solid waste (incineration ash) in the incinerating system was larger than that in the composting system, because the compost was finally used in the farm.