Abstract: An self-powered apparatus for moving objects that can be rolled or dragged across a surface, one embodiment of the apparatus operating on either of front or rear endless track pairs the apparatus center of gravity being forwardly and rearwardly shiftable to select between use of the front or rear endless tracks for movement of the vehicle across a surface.

Abstract: An self-powered apparatus for moving objects that can be rolled or dragged across a surface, one embodiment of the apparatus operating on either of front or rear endless track pairs the apparatus center of gravity being forwardly and rearwardly shiftable to select between use of the front or rear endless tracks for movement of the vehicle across a surface.

Abstract: A self-destructing fish hook having a selected small anodic area of exposed steel, and a highly cathodic plating covering a much larger area of the hook surface. When immersed in seawater, the resulting galvanic couple causes the small anodic area to corrode rapidly and the hook to eventually break. In a preferred embodiment, a temporary protective coating is provided for at least one member of the couple to delay the onset of corrosion of the steel anodic area so that the hook can retain 100 percent of its strength for a substantial period of usage in seawater before corrosion of the steel body is initiated.

Abstract: A directional Doppler fish movement detector uses a relatively low ultrasonic frequency to minimize particulate scattering and absorption losses in turbid lakes and streams. The low ultrasonic frequency also minimizes Doppler noise caused by boat drift and wave action. To compensate for the relatively low frequency Doppler signals which result, including sub-sonic Doppler signals from slow moving fish, means are provided for doubling, or otherwise multiplying, the frequency of the Doppler signal to improve audibility. Means are also included which allow the relatively wide beam of the Doppler fish movement detector to be directed over a wide horizontal angle, and in one of the preferred configurations, the transducer assembly is attachable to the underwater portion of an electric propulsion motor so that the ultrasonic beam is directed along the line of thrust.

Abstract: An improved contraceptive device comprising a condom of conventional shape and material such as latex. A large number of small holes in the condom allow the transfer of hormonal, pheromonal, and other bio-active fluids during sexual intercourse. The cross sectional diameter of the holes is made small enough to impede the passage of human spermatozoa so that the contraceptive function is retained.

Abstract: Apparatus for obtaining a series of concentrated samples of dissolved, particulate or emulsified substances from seawater. A relatively large measured volume of seawater is pumped through each of a series of in situ sampling chambers containing filtration, adsorption, absorption, or other retentive material. The instrumented housing with appended sampling chambers is preferably suspended from a surface vessel by an electrical cable through which it is remotely controlled and powered to obtain measured samples at various depths. Alternatively, a programmed controller and battery power pack can be attached to obtain an unattended time series of samples from a fixed location either on the sea floor or suspended beneath a buoy.

Abstract: A seabed referenced fish detection system for detecting aquatic animals within a predetermined zone relative to the bottom of a body of water. Preferably, fish are detected within a predetermined zone contiguous with the bottom without the need for range switching to accommodate changes in depth. A pair of ultrasonic pulses are transmitted, preferably of different frequencies, and separated by a predetermined time delay. The bottom echo from the first ultrasonic pulse initiates a gate interval during which echoes from the second ultrasonic pulse are detectable. When the time delay and the gate interval are equal, the gate interval terminates immediately before the reception of the second bottom echo, so that only echoes from above the bottom, e.g., fish echoes, can trigger an audible output signal. Since fish detection events are un-ambiguously indicated by an audible signal, the need for a graphic recorder or C.R.T. to distinguish and interpret fish and bottom echoes is eliminated.

Abstract: A method and apparatus for measuring the rate of flow and the totalized quantity of thermal energy flowing through a conduit. A small proportion of the thermal energy flowing through a conduit is by-passed to a heat exchanger, which is otherwise isolated from the thermal energy in the conduit, and shunted to a heat sink maintained at a reference temperature. The temperature differential along the heat shunt is measured as an indication of the total heat flow through the conduit.