Fig. 5
From: Plasticiser loss in heritage collections: its prevalence, cause, effect, and methods for analysis
Schematic showing key mass transport parameters used to describe the emission of additives into the surrounding environment. The dashed line illustrates the conceptual air-boundary layer used in many emissions models. Parameters used in emissions models include the diffusion coefficient through the material, Dm, the material/air partition coefficient Km, the convective mass transfer coefficient, hm, and the concentration in the air boundary layer at the surface, y0