The Great East Japan Earthquake generated a huge amount of disaster-related waste. If soil generated from wood chips derived from woody waste materials is to be effectively used as a material in soil ...structure, the settlement and stability characteristics of this material should be considered. In this study, a series of laboratory tests was carried out, exposing soil composed of different ratios of wood chips to varying compaction degrees. The unconfined compressive strength decreased and the stress–strain curve exhibited more ductile behaviour as the wood chip content increased, while the opposite tendency was exhibited as the compaction degree increased. Deviator stress was not influenced by the mixing rate. The cement-mixed soil exhibited the effect of curing on strength properties, with crushed stone concrete-mixed soil displaying similar tendencies.
We carried out the selective area growths of GaN on semipolar ($20\bar{2}1$), ($20\bar{2}\bar{1}$), and related non- and semi-polar GaN substrates by metalorganic vapor phase epitaxy. By changing the ...growth parameters and directions of the SiO 2 stripe mask, the differences in GaN structures between the growths on the different substrates were investigated. In the case of the stripes $\parallel$ $a$-axis, anisotropic GaN structures with ($000\bar{1}$) and ($10\bar{1}1$) facets were obtained for all the non- and semi-polar GaN substrates. On the other hand, in the case of the stripes $\perp$ $a$-axis, isotropic GaN structures were obtained for the ($20\bar{2}1$) and ($20\bar{2}\bar{1}$) GaN substrates. However, the GaN structures between them were quite different. After 120 min of growth, $\{11\bar{2}0\}$ and ($20\bar{2}\bar{1}$) facets markedly expanded for the ($20\bar{2}1$) and ($20\bar{2}\bar{1}$) GaN substrates, respectively. Moreover, by exploiting the effect of growth temperature, the growth of a continuous ($20\bar{2}\bar{1}$) GaN layer with voids was realized.
Four series of glass matrix/glass particle composites where the thermal expansion coefficient of the matrix is similar to or higher than that of the dispersed particles were prepared by hot-pressing ...technique. Optical microscopy indicated that, in the case of larger thermal expansion mismatch between particle and matrix, microcracks were formed radially around particles during cooling of the composite body from its fabrication temperature. The Young's modulus for each composite was determined from the load-deflection curve of a rectangular bar specimen tested in three-point bending. Using a two-dimensional model, a theoretical analysis was made of the elastic modulus of two-phase, particulate composites containing microcracks. This analysis enabled the overall Young's modulus of such composites to be correlated with the size and density of the microcracks. The Young's modulus behavior of the prepared composites could be well explained on the basis of the analysis, and the size and density of the microcracks existing in the composites were reasonably estimated.
The groundwater pollution by tetrachloroethylene and trichloroethylene that actually takes place is demonstrated in this peper. In order to understand the mechanism of pollution, simple experiment is ...carried out and qualitative discussions are made. Applying the results obtained from the experiment to the actual pollution, the mechanism of the pollution is predicted as follows: (1) The fall velocity of tetrachloroethylene is rapid; (2) Small droplets of tetrachloroethylene are retained in interstices of porous medium; (3) A stratified layer of tetrachloroethylene is formed on the impermeable bottom; and (4) The two-phase flow pattern tekes place. Some discussions required for the quantitative estimation based on the mathematical analyses are also given.
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