Viscosity of binary Zn-Sn melt has been measured by the use of a oscillating viscometer in order to study the effect of compositional inhomogeneity in the cylindrical crucible and to obtain the reliable viscosity of the melt. Gas bubbling device was introduced to homogenize the melt in the crucible. Apparent viscosities were measured for inhomogenized and homogenized melt, then the former showed lower value than the latter, and the inhomogeneity of the melt was considered to affect the viscosity measurement. Viscosity of the melt decreases steeply with increasing Sn content up to the composition of about 50at%Sn, then maintains approximately constant value to pure Sn. Apparent activation energy of viscous flow also decreases with increasing Sn content. This kind of de-crease of the viscosity and the apparent activation energy of the mixture is considered to relate the volume expansion and the positive enthalpy of mixing.
The literature on the thermophysical properties for fluid mixtures of the water+ammonia system has been retrieved, and the experimental data on the vapor-liquid equilibrium and thermodynamic properties were collected. The available equations of state for the present system were evaluated by means of the comparison with these experimental data. We recommend that the equation of state proposed by Ziegler and Trepp be used for calculating the thermodynamic properties and the vapor-liquid equilibrium for the water+ammonia mixtures in the range of temperatures and pressures up to about 450K and 5MPa.
The “equivalent inclusion” method, originally devised by Eshelby for solving the disturbance of a uniform elastic field due to an ellipsoidal inhomogeneity in an otherwise homogeneous elastic medium, is used to estimate the effective thermal conductivity of a multiphase system characterized by a random dispersion of N different sets of arbitrarily oriented ellipsoidal particles in an isotropic matrix. The effect of particle interaction is taken into account with the “mean-field approximation” which has been established in the micromechanics-of-composites area. Simple expressions are derived for the binary systems containing perfectly aligned or randomly oriented fibers or platelets as well as spherical particles. The significance of the present approach is demonstrated in comparison of these expressions with the bounds given by Hashin and Shtrikman. Other existing results including those due to Maxwell and Landauer are also discussed.