Search

The purpose of this study is to review of Japanese related literature about the play with sand of young children and is to examine some issues that remain to be explored in this field. First, we collected 57 documents (papers or literatures) about the play with sand of young children and classified them in nine categories. Secondly, about nine classified categories, we surveyed each results of research. Finally we discussed some issues about a future research in terms of the play with sand. As a result, three points of the next were clarified. (1) It is necessary to study individual differences and the relationships between young children. (2) It is necessary to study the support of the early childhood educators. (3) It is necessary to compare with foreign results of this research.

細粒分含有量5&acd;84%のさんご礁堆積物について変水位透水試験を実施し, 透水係数に及ぼす細粒分含有量の影響について検討した。主な結果は次のようである。1) 細粒分含有量20%以上においては細粒分含有量と平均粒径との間に相関性が認められる。2) 透水係数の対数(In k)と間隙比eの間には線形関係が認められ, その傾きは細粒分含有量の増加にともなって増大する。3) 細粒分含有量20%以上では透水係数は(10)^<-3>&acd;(10)^<-4>(cm/s)のオーダーにある。4) 細粒分含有量が増加すると, 透水係数kはe^3/(1+e)と比例関係が成立しなくなる。5) 透水係数は細粒分含有量の増加にともなって減少する。6) さんご礁堆積物の透水係数は細粒分含有量から推定可能である。, A series of variable-head permeability tests has been performed on reconstituted carbonate sand with various fraction finer than 75μm. Major conclusions obtained in this study are as follows. (1) There exists a liner relation in the relationship between the logarithm of the coefficient of permeability and void ratio for individual fraction content. (2) The value of permeability ranges between (10)^3cm/s and (10)^4cm/s for sands contained fraction more than 20%. (3) The relationship between the coefficient of permeability k and the content of fraction is derived in a given void ratio based on the liner relation for ln k versus void ratio e. (4) The coefficient of permeability of carbonate sands can be evaluated by using fraction finer than 75μm.