Abstract: A system for sonically probing a seabed comprises at least one row (14) of transducers (22) that each can produce a sonic beam, and at least one sonic detector (24). Each transducer is independently energized to produce a narrow sonic beam (40), with resulting seabed or subsea echoes being detected to produce one pixel of a display (60, 80, 90, 150) formed by an X-Y array of pixels, before a next transducer is energized and its echoes are detected to produce another pixel of the display. When the system detects a large change in echo amplitude at adjacent seabed locations, then scanning at those locations is accentuated by analysis and by additional sonification at different frequencies. The transducers are closely spaced, at a center-to-center distance (G) of less than 25 cm, to provide good horizontal resolution and usually lie within 6 meters from the seabed. Each transducer is energized to produce a sonic pulse which, dependent on the application, has a carrier frequency (32) of at least 200 kHz.

Abstract: The present invention is directed to the preparation of in-situ formation of a series of glass-ceramic composites by the Self-propagating High temperature Synthesis (SHS) technique with advantages of processing simplicity as well as the potential of cost savings. The materials produced by the technique contain crystalline TiB2 phase and have either a pure glassy matrix or a glass matrix with partial devitrification based on the Al2O3—CaO system. The materials can potentially be used for infrared light transmission and for other high temperature applications. These materials can also be produced with relatively high porosity.

Abstract: A method and apparatus for evaluating a live shellfish (S), especially a lobster or crab, to determine the MC, or meat ratio (meat divided by meat plus water). A pair of transducer devices (12, 14) are pressed against opposite sides of the shell of a live shellfish to determine the velocity of sound through it. The transducer devices are pressed without substantially deforming or cracking the shell, to avoid injury to the shellfish. Good acoustic coupling to the shell is achieved by applying a sound-transmitting gel (240, 242) to the face of each transducer device. If the velocity 1560 m/sec, this indicates an MC of 7%, indicating that the shellfish is unsuitable for harvest. If the velocity 1660 m/sec. then this indicates an MC of 19%, which indicates that the shellfish is ready for harvesting, that is, for shipping to restaurants or markets for human consumption. A velocity of 1600 m/sec. indicates an MC of 12% which is about a borderline between acceptance and rejection.

Abstract: Apparatus for producing an objective assessment of the size of fish in an aquaculture setting. The apparatus includes a sonic transducer (30) with a transmitter that is driven to generate time-spaced pulses that move along a sonic beam path (32) of small spread angle, and a sonic detector that detects echos of the transmitted pulses which result whenever a fish enters the sonic beam. An analyzing circuit analysis the echos to provide an estimate of the size of the fish that produced the echoes. The analyzing circuit detects the time between the leading and trailing edges of an echo, which indicates the thickness of the fish. A measurement of the peak amplitude of the echo and of the integral of echo energy also indicates the size of the fish.

Abstract: A system is described that uses acoustic energy to position an object, which simplifies the application of forces in defined directions to the object and which enables the application of large forces to the object. The system includes transducers (21-24, FIG. 1) that direct separate acoustic beams (31-34) at the object (12), with the system constructed so the beams do not create standing wave patterns. A plurality of beams whose phases at the object are not closely controlled, are directed at different surface areas of the object so the beams do not substantially overlap at the object and create possible canceling effects. A very large force is applied to the bottom (124 FIG. 8) of an object lying in a gravity environment, by directing a plurality of beams (141-145) at the same area at the bottom of the object, and with the beams being controlled so they are substantially in phase at the object area. This plurality of beams can also replace one or all of the transducers (21-24, FIG.