Thickening

The process or result of replacing a subspace A ⊂ M by a neighborhood N ⊂ M that is homeomorphic to a manifold-with-boundary and contains A as a deformation retract; often called a regular neighborhood in manifold and PL settings.

A solid–liquid separation process that increases slurry solids concentration by allowing particles to settle under gravity (often aided by flocculants and mechanical raking) and removing clarified overflow while discharging a denser underflow.