Abstract: Methods and apparatus for controlling aircraft inlet air flow. The apparatus can include an external flow surface having a forward portion, and an engine inlet positioned at least proximate to the external flow surface and aft of the forward portion. The engine inlet can have an aperture and can be coupled with an engine inlet duct to an engine location. An auxiliary flow duct can be positioned at least proximate to the external flow surface and can include a first opening and a second opening spaced apart from the first opening. The first opening can be positioned to receive flow from the external flow surface during at least a first portion of an operating schedule of the propulsion system. The auxiliary flow duct can be configured to direct air to the engine location during at least a second portion of the operating schedule of the propulsion system.

Abstract: Methods and apparatus for controlling aircraft inlet air flow. The apparatus can include an external flow surface having a forward portion, and an engine inlet positioned at least proximate to the external flow surface and aft of the forward portion. The engine inlet can have an aperture and can be coupled with an engine inlet duct to an engine location. An auxiliary flow duct can be positioned at least proximate to the external flow surface and can include a first opening and a second opening spaced apart from the first opening. The first opening can be positioned to receive flow from the external flow surface during at least a first portion of an operating schedule of the propulsion system. The auxiliary flow duct can be configured to direct air to the engine location during at least a second portion of the operating schedule of the propulsion system.

Abstract: This invention provides a method of preparing an isomerization catalyst by contacting an alkali metal with catalyst support particles in a fluidized bed. After the alkali metal is uniformly dispersed on the support particles, oxygen is added to the fluidizing gas to oxidize a portion of the alkali metal.

Abstract: This invention provides a method of preparing an isomerization catalyst by contacting an alkali metal with catalyst support particles in a fluidized bed. After the alkali metal is uniformly dispersed on the support particles, oxygen is added to the fluidizing gas to oxidize a portion of the alkali metal.

Abstract: Boundary layer control apparatus is provided (22). The boundary layer control apparatus (22) is for use with an aircraft propulsion nacelle (12) positioned such that the air inlet (14) of the propulsion nacelle is located proximate an aircraft surface (10), wherein a boundary layer is established on the surface when the aircraft is propelled through an atmosphere, causing air to flow over the surface. The boundary layer control apparatus (22) includes a duct having an entrance (24) positioned between the aircraft surface (10) and the inlet (14) of the propulsion nacelle (12) for capturing the boundary layer air passing over the aircraft surface and diverting the boundary layer air away from the inlet.

Abstract: A hydrotreating catalyst is described which comprises at least one Group VI metal, metal oxide, or metal sulfide, and at least one Group VIII metal, metal oxide, or metal sulfide, supported on a carrier wherein (A) the catalyst comprises from about 10% to about 35% by weight of combined metal, and the atomic ratio of the Group VIII metal to Group VI metal is in the range of from about 0.5:1 to about 2:1; (B) the carrier comprises from about 0.5 to about 10 weight percent of halogen, from about 0.5 to about 5% by weight of silica and from about 85 to about 99% of alumina; and (C) the catalyst is characterized as having a median pore radius of from about 30 to about 65 Angstroms, and a surface area of from about 120 to about 180 m.sup.2 /g.

Abstract: A hydrotreating catalyst is described which comprises at least one Group VI metal, metal oxide, or metal sulfide, and at least one Group VIII metal, metal oxide, or metal sulfide, supported on a carrier wherein (A) the catalyst comprises from about 10% to about 35% by weight of combined metal, and the atomic ratio of the Group VIII metal to Group VI metal is in the range of from about 0.5:1 to about 2:1; (B) the carrier comprises from about 0.5 to about 10 weight percent of halogen, from about 0.5 to about 5% by weight of silica and from about 85 to about 99% of alumina; and (C) the catalyst is characterized as having a median pore radius of from about 30 to about 65 Angstroms, and a surface area of from about 120 to about 180 m.sup.2 /g. Also described are novel and improved procedures for preparing the carrier or support used to prepare the catalysts.

Abstract: A hydrotreating catalyst is described which comprises at least one Group VI metal, metal oxide, or metal sulfide, at least one Group VIII metal, metal oxide, or metal sulfide, and a halogen supported on a carrier wherein(A) the catalyst comprises from about 10% to about 35% by weight of combined metal and the atomic ratio of the Group VIII metal to Group VI metal is in the range of from about 0.5:1 to about 2:1;(B) the catalyst contains from about 0.5 to about 10% by weight of halogen;(C) the carrier comprises from about 10 to about 50% by weight of silica and from about 40 to about 90% of alumina; and(D) the catalyst is characterized as having a median pore radius of from about 20 to about 90 Angstroms, and a surface area of from about 90 to about 230 m.sup.2 /g.The catalyst is useful in the production of lubricating oils from crude lubricating oil stocks.