In a previous work, single particles of commercial sinterwere reduced stepwise with CO-C02-N2 gas mixtures. In the analysis, the reduction of calcium ferrite (CF) was not taken into consideration.Vaiues of chemical reaction rate constants kc and effective diffusivities De in the unreacted-core shrinking model were determined by trial and error so that the calculated reduction curve might agree with the experimental one.In the present work, the method of the kinetic analysis are re-examined:(

In order to reduce the exhaustion of carbon dioxide, the utilization of unused woody biomass such as forestry biomass and pruned branch has come to attract attention as an alternative fuel of coal. Most of the coal are used at coal-fueled power plants and iron mills. In the present study, bio-solid fuels to alternate coal cokes are investigated. Pruned branches of ume and persimmon which are the typical fruit trees cultivated in Wakayama prefecture are used as biomass resources. To establish a technical basis for the method of manufacturing bio-solid fuel with high hardness, effects of molding temperature, tress species and diameter of pruned branch on compressive strength properties of bio-solid fuel are clarified. The results obtained are as follows. In the case of ume, the compressive strength has a maximum, when the molding temperature is 140-160 degree C. There is no effect of diameter of pruned branch on compressive strength. In the case of persimmon, the compressive strength has a maximum, when the molding temperature is 180 degree C. The compressive strength decreases with decreasing the diameter of pruned branch. The difference in compressive strength between ume and persimmon is considered to be caused by the particle shape.

No abstract

The utilization of unused biomass such as logging residues and broadleaf trees has come to attract attention to protect forests and satoyamas (a Japanese term for undeveloped woodlands near populated areas) in Japan. In this study, the modification of bio-coke fuels as an alternative to coal coke is investigated by using bamboo and Japanese cedar, which are the typical domestic woody biomass in forests and satoyamas. To improve the compressive strength under high temperature environment and the heating value of bio-coke, carbonized Japanese cedar is mixed with bamboo. The effect of the carbide mixture on the forming characteristics of bio-coke such as density, compressive strength, and heating value are experimentally clarified. The results obtained in the present study are as follows:(1) the density of bio-coke increases with increase in forming temperature and forming pressure, but is reduced by the addition of carbide as the thermoplastic polymer is reduced (2) the increase in carbide reduces the compressive strength under normal temperature environment and improves the compressive strength under high temperature environment. When the carbide content was 30%, the compressive strength under high temperature environment was 3.26MPa. (3) The addition of carbide is an effective way to improve the compressive strength under high temperature environment and to enhance the heating value of bio-coke.

Joint dislocation is a critical problem of total hip replacement. We have newly proposed an artificial hip joint with a structure that prevents dislocation. The proposed joint has a simple form with a femoral head partially covered with an acetabular cup. In the present study, the effects of inset heights and slit configurations of the cup on the pull-out forces of the joint were evaluated using finite element analysis. Joint models with different inset heights and those with or without a slit in the cup were used for the analyses to estimate the pull-out forces of the joint. In the case without the slit, the maximum pull-out force of the joint with 1.0 and 1.5 mm of the inset height was approximately 12 and 40 N, respectively. In the case of 1.0-mm inset height, the maximum force of the joint with and without the slit was approximately 9 and 12 N, respectively. These results reveal that the maximum force is markedly changed by the inset height and is moderately affected by the slit. Thus, we can gain insights into a strategy to optimally design an artificial joint in which dislocation does not occur easily.