Ikuro Shishido

ON THE DRYING MECHANISM OF SHRINKAGE MATERIALS

ABSTRACT Effects of moisture content on Liquid transport properties (Permeability and suction pressure) and mechanical properties (Youngs modulus, yield stress and tensile strength) of drying shrinkage materials (Kibnshi, IIaido and mixed clay) were measured and a strong dependence was found. When glass beads are added to the Kibushi, permeability increase and Youngs modulus and yield stress decrease in spite of the same suction pressure and tensile strength. Changes in local moisture content and stress during drying was calculated by using finite-element method, taking into account the stress gradient in addition to the pressure gradient due to osmotic suction.

Heat Transfer Characteritics of Cascade Heat Pipe

A prediction method for the heat transfer characteristics of a cascade heat pipe is developed by solving nonlinear simultaneous equations.It is shown that this method predicts well the experimental values of the heat tranfer rate. It is confirmed that the heat transfer characteristics of cascade heat pipes such as thermal diode and thermal switching are predicted satisfactorily by this method.

Development of a cascade heat pipe.

熱ダイオード特性を持つカスケード型のヒートパイプを試作し, その伝熱特性について実験的に検討した。その結果熱ダイオード効率は0.85以上のものが得られた.また, この試作したヒートパイプの中間部はある温度を境として蒸発部にも凝縮部ともなり得ることが明らかとなった。さらにこの熱入出力反転温度は簡単な式で表現できることが示された.

A New Measurement Method of Liquid Transport Properties

Liquid transport properties, such as suction pressure, permeability and apparent moisture diffusivity, were measured for wide range of degree of liquid saturation within wet material to be dried. Wet sample was pressurized-by N2 gas and drained water through membrane filter was measured continuously by a micro processor system. Suction pressure was determined from the equilibrium data. Permeability and difusivity were estimated from the transient change of the drained water volume, by using a linearized transport equation in each small increment of pressure.