Abstract: A device for the determination of the frictional characteristics of large surfaces comprising: a frame; a drive motor mounted atop the frame; a drive train; a horizontal measurement arm attached to the drive train and capable of circular rotation; a spherical frictional slider attached to the distal end of the measurement arm that contacts and slides along a surface under evaluation; the frictional slider comprising a spherical member that directly engages the surface under evaluation; and a tangential force detector on the measurement arm to measure the resistance encountered by the spherical member as it slides along the surface under evaluation.

Abstract: A method for joining together two ceramic items involves the steps of applying microwave radiation to the ceramic items, simultaneously applying compressive forces to the ceramic items in order to force such ceramic items together, and continually monitoring the joint being formed between the two ceramic items. An apparatus of three elements carries out the method. These elements are a single mode microwave applicator; a compressive force applicator; and a nondestructive evaluator for monitoring the formation of the joint.

Abstract: A method for joining together two nonoxide ceramic items involves a preliminary step of either creating a vacuum or overpressurizing a cavity, followed by the steps of applying microwave radiation to the ceramic items, simultaneously applying compressive forces to the ceramic items in order to force such ceramic items together, and continually monitoring the joint being formed between the two ceramic items. An apparatus of four basic elements carries out the method. These elements are a vacuum/overpressurization system; a single mode microwave applicator; a compressive force applicator; and a nondestructive evaluator for monitoring the formation of the joint.

Abstract: Methods and apparatuses for electrically investigating a borehole are described. Tool mounted pads are provided, each with a plurality of small measure electrodes from which individually measurable survey currents are injected toward the wall of the borehole. The measure electrodes are arranged in an array in which the measure electrodes are so placed at intervals along at least a circumferential direction (about the borehole axis) as to inject survey currents into the borehole wall segments which overlap with each other to a predetermined extent as the tool is moved along the borehole. The measure electrodes are made small to enable a detailed electrical investigation over a circumferentially contiguous segment of the borehole so as to obtain indications of the stratigraphy of the formation near the borehole wall as well as fractures and their orientations.