Abstract: A first control unit sends a heartbeat message to a subscriber unit, the subscriber unit forwards the heartbeat message to a second control unit, and the second control unit makes a master/backup decision based on the heartbeat message.

Abstract: The current disclosure determines if structural faults exist and extracts geometric features of the structural faults from acoustic emission waveforms, such as crack length and orientation, and can evaluate the structural faults online, during normal operation conditions.

Abstract: The current disclosure determines if structural faults exist and extracts geometric features of the structural faults from acoustic emission waveforms, such as crack length and orientation, and can evaluate the structural faults online, during normal operation conditions.

Abstract: The current disclosure determines if structural faults exist and extracts geometric features of the structural faults from acoustic emission waveforms, such as crack length and orientation, and can evaluate the structural faults online, during normal operation conditions.

Abstract: The current disclosure determines if structural faults exist and extracts geometric features of the structural faults from acoustic emission waveforms, such as crack length and orientation, and can evaluate the structural faults online, during normal operation conditions.

Abstract: The current disclosure determines if structural faults exist and extracts geometric features of the structural faults from acoustic emission waveforms, such as crack length and orientation, and can evaluate the structural faults online, during normal operation conditions.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Active carbon filters and systems that are operative to detect active carbon filter degradations are provided. The active carbon filter can include a carbon filter comprising activated carbon and defining a filter surface; a first piezoelectric wafer active sensor on the filter surface that is electrically isolated from the carbon filter; and a second piezoelectric wafer active sensor on the filter surface that is electrically connected to the filter surface; and an impedance monitoring device electrically connected to the first piezoelectric wafer active sensor and the second piezoelectric wafer active sensor. Methods are also disclosed for determining if any degradation has occurred in an active carbon filter.

Abstract: Methods of forming a molded composite material are generally provided. A composite forming precursor (e.g., fibers and/or a resin material) can be applied onto a mold that includes a plurality of piezoelectric sensors embedded into the mold. The composite forming precursor can then be cured adjacent to the mold to form a molded composite material. During curing, the molded composite material can be monitored, using the piezoelectric sensors to detect any defects formed during curing.

Abstract: A method and device for performing ultrasonic damage detection in a thin-wall structure using an array of embedded Piezoelectric Wafer Active Sensors (PWAS) for the transmission and reception of guided waves and a signal processing methodology based on the beamforming process. The beamforming signal processing has been adapted to the specifics of guided elastic waves traveling in thin-wall structures.

Abstract: A method and device for performing ultrasonic damage detection in a thin-wall structure using an array of embedded Piezoelectric Wafer Active Sensors (PWAS) for the transmission and reception of guided waves and a signal processing methodology based on the beamforming process. The beamforming signal processing has been adapted to the specifics of guided elastic waves traveling in thin-wall structures.