Abstract: There is described a method for interrogating optical fiber comprising fiber Bragg gratings (“FBGs”), using an optical fiber interrogator. The method comprises (a) generating an initial light pulse from phase coherent light emitted from a light source, wherein the initial light pulse is generated by modulating the intensity of the light; (b) splitting the initial light pulse into a pair of light pulses; (c) causing one of the light pulses to be delayed relative to the other of the light pulses; (d) transmitting the light pulses along the optical fiber; (e) receiving reflections of the light pulses off the FBGs; and (f) determining whether an optical path length between the FBGs has changed from an interference pattern resulting from the reflections of the light pulses.

Abstract: A clearance control assembly for a gas turbine engine that defines an axial direction and a radial direction and includes a stage of rotor blades and a shroud hanger. The assembly includes a case configured to be positioned outward along the radial direction from the stage of rotor blades when installed in the gas turbine engine. The case is further configured to be engaged with the shroud hanger at a first location when installed in the gas turbine engine. The assembly also includes a baffle positioned outward along the radial direction from the case to define a chamber therebetween. The baffle has a forward end and an aft end. The forward end of the baffle is engaged with the case to form a first seal and the aft end of the baffle is engaged with the case to form a second seal. The baffle, the case, or both define an inlet to allow a fluid to enter the chamber and the case defines an outlet to allow the fluid to exit the chamber.

Abstract: An ergonomic pillow for greatly increasing comfort and ability to lie on a pillow while using an ear covering or inserted audio device. It has a cutout section to accommodate one half of a pair of conventional headphones with the over-the-head band. It has an optional insert that matingly conforms to and completely fills the cutout section to convert the pillow to a standard configuration. Within the insert are a pair of removable nesting inserts sized for earphones or earbuds. The pillow will make resting ear-down possible with an audio listening device. The pillow offers increased comfort and neck support for one wearing audio listening devices and the additional benefit of external sound reduction.