Effects of oxide additive on thermoelectricity of FeSi2
Thermoelectricity has been hot issue in these days, because of environmental problems and energy sources deficit. Moreover, material development for thermoelectricity is now busy in oxide and metal or alloy, basically. However, conclusive materials with good performance have not yet been found in application basis. We have studied oxide-added beta-FeSi2 for these years. Iron disilicide is well known and utilized in relatively higher temperature. In this report, we indicated our successful improvement of performance of beta-FeSi2 added with Ta2O5 showing the figure of merit almost 0.3 times 10-3/K This was obtained by reducing thermal conductivity and electrical resistivity (a half of standard FeSi2)
Effect of Electronic Structure on Seebeck Coefficient of Oxide Thermoelectric Semiconductor and Role of the Oxide
An oxide is functionally classified into two categories when regarding oxide as thermoelectricity: 1) an oxide itself has thermoelectric properties such as CaMnO3, homologous series of (ZnO)m and NaCo2O4, and they have been researched since around 1995. 2) there are researches on oxide as an additive to conventional thermoelectric material. We have investigated to approach thermoelectric property from the electronic structures by ab initio calculation. We propose to estimate Seebeck coefficient of oxide by regarding movement of electron between energy levels in the electronic structures. Thereby, it will lead to a new thermoelectric material of oxide. Furthermore, we can improve figure of merit by adding oxide to FeSi2 due to reducing thermal conductivity in the present study.
Wood Microbiology: Decay and Its Prevention
Introductory text on the principles of decay and discoloration processes in wood, with emphasis on the major fungal damages which may develop during the growth, storage, and use of wood. The characteristics, detection, effects, and control of microbial attacks are stressed. Provides a synthesis of the current literature on wood microbiology, a rapidly expanding field of study. (Abstractor's note: This is an important resource for conservation researchers studying the decay of wood in art and architecture.) The following is a list of chapter headings: 1) Introduction to wood microbiology; 2) Wood deterioration agents; 3) Characteristics and classification of fungi and bacteria; 4) Factors affecting the growth and survival of fungi in wood (fungal ecology); 5) Fungal metabolism in relation to wood decay; 6) The decay setting: some structural, chemical, and moisture features of wood in relation to decay development; 7) General features, recognition, and anatomical aspects of wood decay; 8) Chemical changes in wood caused by decay fungi; 9) Ultrastructural features of wood decay; 10) Changes caused by decay fungi in the strength and physical properties of wood; 11) Colonization and microbial interactions in wood decay; 12) Decays originating in the stems of living trees; 13) Biodeterioration of stored wood and its control; 14) Wood stains and discolorations; 15) Decay problems associated with some major uses of wood products; 16) Detection of internal decay; 17) Paint mildew and related degradative problems; 18) Natural decay resistance (wood durability); 19) Chemical protection of wood (wood preservation); and 20) Some trends in wood microbiology research and a new emphasis (biotechnology). -- AATA