An optical device and method providing multi-channel bulk optical power monitoring is disclosed. Boundary layer control includes passive systems such as riblet films and boundary layer propulsion devices having a divided and distributed propulsion system disposed in the curved aft sections of aircraft and airships including hybrid aircraft susceptible to boundary layer drag due to degree of curvatures, speed and density of the surrounding air. The stent may have a radially compressed configuration and a radially expanded configuraton, in which the first section has a first shortening ratio, and the second section has a second shortening ratio less than the first shortening ratio. The closure assembly permits flow through the passage when the container is conveyed into the passage, and the closure assembly prevents flow through the passage when the container is removed from the passage. The compressibility of the wet paper contacting layer is larger than that of a layer formed of the base layer, the first batt layer and the second batt layer.