Abstract: The weight of liquid in a tank subject to tilting is determined by measuring differences in air pressure in the ullage (the empty volume of the tank above the level of the liquid) and the air pressure produced by the weight of the liquid at the bottom of the tank. The pressures at the bottom of the tank are measured in a plurality of locations, and the differential pressures are combined to compensate for changes in the depth of the liquid when the tank is not level (e.g., when the tank is in an aircraft flying at an attitude other than straight and level). The electronics to measure the pressure and to process the pressure measurements are located remotely form the tanks, thus eliminating the possibility of ignition caused by the electronics when the liquid is fuel or other flammable liquid.

Abstract: A watercraft has at least two narrow hulls with a shallow draft and has one or more passive flotation devices that are entirely submerged. The hulls enclose the power trains for the watercraft and are accessible from the compartments of the watercraft. The passive flotation devices do not include a power train or any other equipment requiring access from the compartments of the watercraft. The narrow, shallow draft hulls have low friction drag and produce a small bow wave. Thus, the watercraft is able to be propelled rapidly, to be propelled for a greater distance, and to be propelled efficiently by the power provided by smaller motors and lighter energy sources.

Abstract: A system and method support the forearm and hand of a user performing repetitive tasks. In one embodiment, the system includes a support bar having a low friction upper surface. First and second cradles are coupled to the support bar to receive and support a user's hands and lower forearms. The cradles have curved bottom surfaces that rest upon the curved upper surface of the support bar to provide a small, low-friction contact area, which enables the user's arms and hands to move effortlessly forward and backwards and left and right. The cradles also tilt and swivel with respect to the support bar. The system and method reduce strains on the arms and shoulders of the user by supporting at least a portion of the weight of the user's arms and hands while the user performs the repetitive tasks.

Abstract: A system and method support the forearms, wrists and hands of a user performing repetitive tasks. A support pad has a low-friction upper surface. A cradle is attached to each of the user's wrists. A first portion of a cradle supports the lower portion of the forearm, including the wrist, when the first portion rests upon the upper surface of the support pad. A second portion of each cradle supports the hand of the user. A retaining device attaches the cradle to the lower forearm. The low-friction upper surface advantageously comprises neoprene material (e.g., wetsuit material). The system and method reduce strains on the arms and shoulders of the user by supporting the user's arms and hands while the user performs the repetitive tasks.