This paper tries to give an overview on technologies using fibrous materials for contributing to environmental and resource matters. The technologies for water treatment include bio-reactive treatment system using membrane hollow fibre, desalination using Ro hollow fibre, purification of water work using UF or MF hollow fibre, purification of recyc

Origin and development of rice cultivation in Japan; Position of rice cultivation in the agriculture in Japan; Rice and food in Japan; Changes in rice production in Japan and the contributing factors therein; Ecological rice crop geography in Japan; Development of rice growing techniques; Development and dissemination of rice growing techniques; The method of paddy rice cultivation in Japan; Upland rice cultivation in Japan; The future problems of rice cultivation in Japan; Growth and development of rice plants.

A Coloring Book (NEW 2023 Edition)

Singular integral equation method has been applied to a lot of crack problems. However, the method has not been widely applied to stress concentration problems such as notch, hole, cavity, or inclusion. In this paper, general solution for elliptical boundaries is formulated in terms of singular integral equations and interaction problems among elliptical holes, ellipsoidal cavities, and cracks are discussed. To formulate the problem, the body force method is applied. Using the Green's function for a point force and a force doublet as fundamental solutions, notch and crack problems are formulated as a system of singular integral equations with a Cauchy-type and a hypersingular kernel, respectively. In solving the integral equations of the body force method, the continuously varying unknown functions of body force densities are approximated by a linear combination of fundamental density functions and polynomials. The accuracy of the present analysis is verified by comparing with the results obtained by the other researchers. The calculation shows that the present method gives rapidly conversing numerical results with high accuracy. Furthermore, it is found that the present method gives the stress distribution along the boundary of hole or cavity very accurately with short CPU time. The present method can be applied to the interaction problems among holes, inclusions, and cracks that are regularly or randomly distributed.

We have been developing a radioactive waste package made of high-strength and ultra low-permeability concrete (HSULPC) for geological disposal of TRU wastes, which is expected to be much more impervious to water than conventional concrete. In this study, basic data for the HSULPC regarding its the impervious character and the thermodynamics during cement hydration were obtained through water permeability measurements using cold isostatic pressing (CIP) and adiabatic concrete hydration experiments, respectively. Then, a prediction tool to find concrete package construction conditions to avoid thermal cracking was developed, which could deal with coupled calculations of cement hydration, heat transfer, stress, and cracking. The developed tool was applied to HSULPC hydration on a small-scale cylindrical model to examine whether there was any effect on cracking which depended on the ratio of concrete cylinder thickness to its inner diameter. The results were compared to experiments. For concrete with a compressive strength of 200MPa, the water permeability coefficient was 4 x 10{sup 19} m/s. Dependences of activation energy and frequency factor on degree of cement hydration had a sharp peaking due to the nucleation rate-determining step, and a gradual increase region due to the diffusion rate-determining step. From analyses of the small-scale cylindrical model, dependences of the maximum principal stress on the radius were obtained. When the ratio of the concrete thickness to the heater diameter was around 1, the risk of cracking was predicted to be minimized. These numerical predictions from the developed tool were verified by experiments.