Abstract: A system and method for identifying an earth fault in a resonant grounded medium voltage network that employs a REFCL compensation system. The method derives a zero-sequence real power from a phase voltage to ground on each phase and a current on each phase and aligns the zero-sequence real power in time with a magnitude of a zero-sequence voltage provided by the REFCL compensation system. The method determines when the zero-sequence real power and the zero-sequence voltage exceed predetermined thresholds. The method delays the magnitude of the zero-sequence voltage for a predetermined period of time when the zero-sequence voltage exceeds the threshold and determines that the fault is occurring when both the time aligned zero-sequence real power exceeds the threshold and the magnitude of the zero-sequence voltage exceeds the threshold for the predetermined period of time at the same time.

Abstract: An exhaust gas heater system for an exhaust system of an internal combustion engine includes a housing and a heating element. The housing includes an outer peripheral wall disposed about a central axis and defining an interior hollow space configured to receive exhaust gas from an exhaust pipe of the exhaust system such that the exhaust gas flows through the interior hollow space. The heating element is positioned within the hollow space and including a first end and a second end. The heating element forms a zig-zag shape extending in a radial direction relative to the central axis.

Abstract: An oil recovery system arranged to recover lubricating oil in a gas turbine engine, the oil recovery system comprising: a separator arranged to extract lubricating oil from a mixture of lubricating oil and air; an oil tank arranged to collect lubricating oil extracted from the mixture; and an exit mast arranged to vent air extracted from the mixture overboard from a core of the engine, wherein the exit mast comprises one or more openings for venting air from the separator; and wherein the one or more openings faces at least partially upstream relative to a direction of airflow through the gas turbine engine, such that the air is vented in the upstream direction, and a dynamic head of any airflow pressurises the oil tank, via the exit mast.

Abstract: There is provided a safety switch having a housing configured to receive a removable key, and a mechanism arranged to be operated when the key is moved from an engaged position to a partially disengaged position, the mechanism being arranged to cause a signal to pass to a separate apparatus, wherein the safety switch further comprises a lock which is controlled by the separate apparatus and is arranged to prevent the key from being fully disengaged from the safety switch until a signal has been received in response from the separate apparatus.

Abstract: There is provided a safety switch having a housing configured to receive a removable key, and a mechanism arranged to be operated when the key is moved from an engaged position to a partially disengaged position, the mechanism being arranged to cause a signal to pass to a separate apparatus, wherein the safety switch further comprises a lock which is controlled by the separate apparatus and is arranged to prevent the key from being fully disengaged from the safety switch until a signal has been received in response from the separate apparatus.

Abstract: Reforming a hydrocarbon, or hydrocarbon derivative, feedstock with steam and/or carbon dioxide using saddle shaped units made of a low silica calcium aluminate cement composition as the catalyst support. The support preferably has a surface area of at least 0.5 m.sup.2 g.sup.-1 and a pore volume of at least 0.1 cm.sup.3 g.sup.-1.

Abstract: A wobbling single slit is provided as the entrance slit of a spectrometer which rectilinearly reciprocates at a constant amplitude, such amplitude being selectively adjustable. A control signal is obtained from a circuit that oscillates the slit for controlling the frequency and phase of the ac signal component detected and amplified from the detector after the superposed dc detected signal component is separated from the ac signal component.