A GIS approach to sediment displacement in mixed sand and gravel beach environments.

Mixed sand and gravel beaches pose special management issues as they are morphologically distinct from either pure sand or shingle beaches. On the mixed sand and gravel beaches of the Canterbury Bight, New Zealand, displacement of sediments operates within a two-part sediment transport system. The large sediments are retained in the beaches, while the fine sand, silt, and mud are transported offshore to the continental shelf.

Theoretically predicted rate constants for mercury oxidation by hydrogen chloride in coal combustion flue gases.

In this work, theoretical rate constants are estimated for mercury oxidation reactions by hydrogen chloride that may occur in the flue gases of coal combustion. Rate constants are calculated using transition state theory at the quadratic configuration interaction (QCI) level of theory with single and double excitations, and are compared to results obtained from density functional theory, both including high level pseudopotentials for mercury. Thermodynamic and kinetic data from the literature are used to assess the accuracy of the theoretical calculations when possible.