Abstract:
A method and apparatus to reduce the axial thrust in rotary machines such as compressors, centrifugal pumps, turbines, etc. includes providing additional peripheral restrictive means (7) attached at the peripheral portion of the disk forming the subdividing means (4) on the side facing the rotating rotor (2). An additional ring element at the periphery of the subdividing means forms additional radial (11) and axial restrictive means (15). Such peripheral restrictive means (7, 11 and 15) function as sealing dams, which combined with the outward flow induced by the rotating impeller, form self-pressurizing hydrodynamic bearings in the axial and radial planes, improving rotordynamic stability. Additionally, a stationary ring element in the center of the cavity forms a seal with the rotor, reducing leakage to suction.
Abstract:
A collagen-based therapeutic delivery device includes an insoluble synthetic collagen-fibril matrix comprising a polymerization product of soluble oligomeric collagen or a polymerization product of a mixture of soluble oligomeric collagen with one or more type of non-oligomeric soluble collagen molecules, such as, for example, soluble telocollagen and/or soluble atelocollagen, and an active agent dispersed throughout the collagen-fibril matrix or within a portion of the collagen-fibril matrix. A pre-matrix composition includes an aqueous solution including soluble collagen-fibril building blocks and an active agent in the aqueous solution. The soluble collagen-fibril building blocks include soluble oligomeric collagen or a mixture of soluble oligomeric collagen with non-oligomeric soluble collagen molecules. The building blocks are operable to self-assemble into a macromolecular synthetic collagen-fibril matrix in the absence of an exogenous cross-linking agent. Methods of making and using the pre-matrix composition and the device are also provided.