Geothermal energy is recovered by (1) introducing into a subterranean heat exchange medium which is in heat exchange with a high temperature formation a liquified vapor which will vaporize at the conditions of the medium; (2) vaporizing the liquified vapor; (3) confining the liquified vapor until pressurized; and (4) recovering pressurized vapor having thermal and pressure-volume energy converted from the high temperature formation.

Aqueous anionic maloaluminate complexes of the structure: ##STR1## at mildly alkaline pH are effective in reducing the incidence and severity of dental caries. These complexes may be advantageously incorporated in aqueous oral compositions, especially dentifrices, having pH values lying in the range of about 7.0 - 9.0.

Disclosed is a disk drive having a linear actuator for carrying read/write heads into engagement with a recording medium. The heads are mounted on a carriage assembly along with a voice coil motor for driving the carriage assembly into and out of engagement of the heads with the medium. The carriage assembly slides linearly on a central guide track. A flexure is provided for the central guide track for linear movement by the carriage assembly so that initial linear movement of the carriage assem...