Abstract: A system for determining a health status of a positive temperature coefficient resistor (PTCR) heater assembly includes a PTCR heater assembly and a health monitoring system. An input voltage is provided to the PTCR heater assembly to provide heating. The health monitoring system includes a first sensor configured to sense the input voltage at the PTCR heater assembly and a second sensor configured to sense a current through the PTCR heater assembly. The health monitoring system is configured to determine a baseline characteristic and an observed characteristic each relating to an inrush peak of the PTCR heater assembly and based on the input voltage and the current. The health monitoring system compares the observed characteristic to the baseline characteristic to assess a health status of the PTCR heater assembly and outputs the health status for PTCR heater assembly diagnostics and/or prognostics.

Abstract: A horizontal inlet section of a jet engine diffuser extends to a transitional curved section which, in turn, extends to a horizontal outlet section offset from the horizontal inlet section to shield observation of infrared and microwave signals from a downstream jet engine. A vane between the inlet and transitional curved sections further shields the observable signals and deflects inlet airflow against the interior wall of the diffuser for minimizing separation of boundary layer airflow from the wall. A backward facing slot is formed in the wall transversely adjacent the vane for effecting low energy boundary airflow to further minimize boundary layer airflow separation.

Abstract: The insulation panel (26) includes a corrugated sheet (28) having a fibrous blanket of insulation (32) secured thereto and an end cap (41) secured to an upper portion of the corrugated sheet (28). The end cap (41) provides a means by which an upper portion of the panel (26) may be anchored to a vertical structural wall (11) to be insulated and a means by which a panel (26) in a next upper row may be supported. After installation, fastening means (43) between the end cap (41) and the corrugated sheet (28) is removed to allow the upper portion of the corrugated sheet (28) to float in the end cap (41) and compensate for thermal expansion and contraction. In another embodiment of the panel (26a), the fastening means (43a) between the end cap (41) and the corrugated sheet (28) is frangible and shears in two upon expansion and contraction of the corrugated sheet (28).