Abstract-Possible origins of lake water, salts dissolved in water of a saline lake , Lake Vanda, those contained in cored sediments of the lake and those distributed on the ground surface in the adjacent area were investigated on the basis of the stable isotope compositions, 13C/12C, 180/160 and 34S/325 .The lake water is concluded to be neither marine nor volcanic in origin but surface fresh water such as glacial melt water, because of the low 8180 values ranging from -30.3 to -31.9%0. On the other hand, sulfate in lake water and in cored sediments from Lake Vanda shows 834S values similar to that of sea water sulfate. Therefore, it is supposed to be marine in origin.Salts distributed on the ground surface near the lake consist mainly of calcite, gypsum, thenardite, sodium niter and halite. The isotopic compositions of carbonate and sulfate minerals range from -14.4 to +17.6%o for 813C and from -0.4 to +22.3%o for 81,10 of calcite and from +14.1 to +20.3 %o for 834S of gypsum. From the isotopic compositions of calcite and gypsum, three different origins, hydrothermal, marine and marine aerosol are considered according to their occurrences and localities. Salts distributed in this area , however, do not constitute the source for those contained in Lake Vanda .The genesis and historical events of the saline lake also were examined. The lake was once a fjord containing sea water and was isolated from the ocean by glaciation after the Tertiary. After the isolation of the lake from the ocean, evaporation of lake water in cold climate and supply of glacial melt water in warm climate have alternately taken place several times.

To improve the controllability of ultrasonic linear motors in the longitudinal-bending mode, we have developed a multilayered transducer with independent electrode sets for the first longitudinal mode and the second bending mode. Since the vibration components are controlled independently by the transducer, it is possible to change only the driving vibration component with the component for friction control kept constant. The optimal shape and area of the electrodes in terms of efficiency were investigated analytically and experimentally. It was confirmed that an electrode shape in accordance with the mode strain contour gave a large output and that an optimum electrode area existed. The transducer with an optimal electrode pattern exhibited an efficiency improvement of approximately 10% and a 30% reduction of the temperature rise during motor operation.

We have computed the x-ray absorption spectrum for the Ti K-edge in rutile titanium dioxide (TiO 2 ) in the frame of the multiple scattering approach, varying the atom positions within the coordination sphere. This allowed us to understand the origin of the absorption structure variation. The analysis has been achieved by making distortions of the axial and equatorial Ti-O distances or of the O eq -Ti-O eq equatorial angle along the c axis. Computations are performed using FEFF (version 6) code for TiO 2 with Dirac-Hara and Hedin-Lundqvist exchange potentials. From the results, we can better understand why the amplitude of one or several structures is modified referring to TiO 2 , when a variation of the local geometry occurs. † Current address:

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To increase the applicability of ultrasonic linear motors, we have developed a holding mechanism for the transducer using parallel leaf springs. The present mechanism is compact since the parallel leaf spring structure has functions for both holding and preloading at the same time. Also, a special design for the spring characteristics provides a non-linear load-displacement region with buckling phenomena. These results in a constant preload for some range of the displacement, then the motor performance does not alter even after abrasion of contact surfaces. In this report, the relationship between the dimension of the leaf spring and the force-displacement curves was investigated in order to obtain the design appropriate for constant preloading. Moreover, the effect of the vibration reduction by the holding mechanism was investigated theoretically and experimentally. The vibration reduction was as small as less than 10 % since the stiffness in terms of the vibration direction was relatively small. Finally, the dynamic responses of the motor with the holding mechanism were measured for a sinusoidal control signal. No prominent peak was observed in the motor's responses, however, the motor velocity change was distorted near the natural frequency of the holding mechanism.