Abstract: A database image may be updated with incremental changes without replicating the production database. Each set of changes to the production database are stored in a differencing disk. Two or more identical chains of differencing disks are created. One chain is an active chain, and database clones may be served from the active chain for use by users. After reaching a predetermined length on an inactive chain, the differencing disks on the inactive chain are merged into a single merged differencing disk, and the inactive chain becomes an active chain, from which new database clones may be served to users. The chains may alternate between being inactive and active chains.

Abstract: A database image may be updated with incremental changes without replicating the production database. Each set of changes to the production database are stored in a differencing disk. Two or more identical chains of differencing disks are created. One chain is an active chain, and database clones may be served from the active chain for use by users. After reaching a predetermined length on an inactive chain, the differencing disks on the inactive chain are merged into a single merged differencing disk, and the inactive chain becomes an active chain, from which new database clones may be served to users. The chains may alternate between being inactive and active chains.

Abstract: A database image may be updated with incremental changes without replicating the production database. Each set of changes to the production database are stored in a differencing disk. Two or more identical chains of differencing disks are created. One chain is an active chain, and database clones may be served from the active chain for use by users. After reaching a predetermined length on an inactive chain, the differencing disks on the inactive chain are merged into a single merged differencing disk, and the inactive chain becomes an active chain, from which new database clones may be served to users. The chains may alternate between being inactive and active chains.

Abstract: There is provided a buoyancy system for a structure having at least one component being substantially stationary with respect to the bottom of a water covered area. The system comprises a set of buoyancy modules of engineered materials to apply an identified amount of buoyancy. The set of buoyancy modules is attached to the structure at a set of buoyancy load transfer locations. The set of buoyancy modules comprises layers of the engineered materials. The engineered materials comprise a substantially reinforced axial layer, a substantially reinforced hoop layer; and a leak prevention layer.

Abstract: An improved mold for use in casting a metal airfoil has an airfoil mold cavity and a starter chamber. A lower end of the starter chamber is formed by a chill plate. A filter is disposed in the starter chamber between the airfoil mold cavity and the chill plate. When an airfoil is to be cast, molten metal is conducted into the starter chamber, into passages in the filter and into the airfoil mold cavity. The molten metal is solidified upward in the starter chamber from the chill plate and through the passages in the filter. The filter blocks migration of impurities from the starter chamber to the airfoil mold cavity as the metal solidifies in the starter chamber. As the molten metal begins to solidify in the airfoil mold cavity, the molten metal is solidified as a large number of columnar grain crystals which extend from the passages in the filter into the airfoil mold cavity.