The method of using a spring network model with a breaking threshold is successful for the pattern formation of cracks in the drying process, in which paste is assumed as an elastic material. However recent researches reveal that the porous and rheological properties of paste influence the fracture process. After reviewing the formation of a crack pattern both in a thin layer of uniformly dried paste and in a directionally dried system, we describe the memory effect found by Nakahara and the drying-rate dependence of crack growth, which are distinctive features different from those in normal solids.

There has been keen interest in micrometer- and nanometer-sized hollow particles since their unique properties such as a lower bulk density and a higher specific surface area as compared to dense particles. Hollow particles are promising materials that are expected to be applied in many industrial fields such as paper making, dyes, cosmetics, optics and electronics. In this paper, synthesis methods for inorganic hollow particles were reviewed and their characteristics were briefly discussed. Recent applications of hollow particles in surface coating, heat insulation, photo catalysis and anti corrosion were also described.

At first a dust explosion phenomenon on the present status of the dust explosion and prevention technology was reviewed based on the main factors related to a dust explosion. And then the possibility on an application to the generation of the electric power energy from the dust explosion energy was examined with energy efficiency based on the governing range of the main factors, the numerical analysis of the reaction modeling and results of wood dust explosion experiments.
The important characteristics values are obtained from a series of dust explosion experimental tests of Sugi tree powder as follows : Lower explosion limit concentration is 80～85 g/m³, Minimum explosion energy 3 mJ＜MIE≦10 mJ, Maximum pressure rising velocity 49.8 MPa/s, Maximum explosion index 15.5 MPa・m/s, Dust explosion class St l, and Maximum explosion pressure 0.861 MPa.
It may be said that the possibility of application of dust explosion energy to generation of electric power energy is not to be zero if the trouble problems based on advanced powder technology and anti-resistant attrition ceramics are solved.