Abstract: This application describes apparatuses, systems, and methods that combines specific configurations of a pneumatic actuation system together with a pressure measurement device to allow for measurement of pressure inside isolated subsystems within the system to thereby provide detection of leaks within the system. In certain exemplary embodiments, the apparatus comprises a directional control valve that employs at least one port connectivity configuration that creates at least one isolated fluid subsystem within the overall system. When the valve is in this isolated subsystem configuration, a given mass of fluid (i.e., compressed gas) can neither enter nor leave the subsystem.

Abstract: The present invention describes a safety mechanism for a directional control valve. The mechanism can be implemented into various valve configurations which are commonly found in the directional control valve industry, including but not limited to those configurations which are adapted to contain a pneumatic fluid-recycling delay function.

Abstract: The present invention relates to salts of meptazinol carbamate prodrugs, and to their synthesis and use.

Abstract: A transistorized invertor which is for inverting d.c. to one or more phases of a.c. and in which for the or each phase to be produced there is provided a current transformer primary in an output line of the invertor with the secondary of the current transformer in a base drive circuit for the invertor, the current transformer being effective to feed a proportion of the output current of the invertor back to the base drive circuit in order to provide base drive current for the base drive circuit.