Some aspects of the Marangoni effect actinng on fluid-fluid interfaces are discu ssed. Origin of the Marangoni effect are classed into three types, namely, thermal, solutal, and yet unfamil iar surfactant monolayer related ones. Upon the thermally induced Marangoni effect, the followings are briefly discussed, 1) stability of two-fluid layers encountered with both the Rayleigh and the Marangoni effects , 2) thermocapillary effect on the characteristics of CZ single crystal puller. On the solutally induced Marangoni effect.condition for the onset of interfacial turbulence during interphacial mass transfer of surface active solutes are discussed. Finally, surface acceleration and stagnation phenomena observed on surface of surfactant solution are described relating to the contamination effect.
Theonset of Marangoni convection in a horizontal liquid layer, the top surface of which is free and the bottom is a rigid wall, is studied theoretically by the Galerkin method. The electric Rayleigh number Ea and the Biot number at the free surface Bi are taken as variables and the effects of Ea, Bi and the boundary condition for ac electric field at the free surface on both the critical Marangoni number Mac and the critical wave number kc are made clear. It is found that the critical wave number increases rapidly when the electric Rayleigh number exceeds 103 and that the system is stable as long as the following relation is satisfied .
Al-Pb-Bi monotectic alloys were processed by using an automatic directional solidification furnace (ADSF) which was specially designed for a KC135 aircraft during a high- and low-G pallaboric flight. Characterization of the alloys were performed by the methods of optical microscopy, scanning electron microscopy, Auger electron spectroscopy, energy dispersive X-ray spectroscopy and superconductivity measurements.