Abstract: The invention relates to a modular system for assembling a hollow structure. The system comprises segments for assembly into modules to assemble hollow structures such as culverts and water-retention systems. The segments comprise opposing sidewalls and a deck spanning said sidewalls having opposing sides and opposing ends which are assembled in inverted, vertically aligned relation to each other to form a hollow module. The segments engage each other with mutually engaging three dimensional structures that prevent lateral and vertical slippage between the segments. The segments may include half-columns that meet along the plane of engagement to form full-height load bearing columns in the assembled structure.

Abstract: The invention discloses a process for the carbonylation of ethylenically unsaturated compounds by reaction thereof with carbon monoxide and a coreactant in the presence of a catalyst system obtained by combining (a) a source of a Group VIII metal cation (b) a phosphine, arsine or stibine compound acting as a ligand; and (c) a source of anions, other than halide anions, carried out in the presence of substoichiometric amounts of halide anions and/or -in case of a coreactant other than an aromatic alcohol- in the presence of a phenolic promoter. The process provides novel alkylphenol esters that may find use as synthetic lubricant.