The cognitive approach began to revolutionize psychology in the late 1950âs and early 1960âs, to become the dominant approach (i.e. perspective) in psychology by the late 1970s. Interest in mental processes had been gradually restored through the work of Piaget and Tolman.
poâ¢rosâ¢iâ¢ty. 1. the state or quality of being porous. 2. (in rock or other natural material) the ratio of aggregated pore space to the volume of the entire mass: used as a measure of the amount of fluid, as oil, that a geologic stratum might hold. [1350â1400; Middle English porosytee porÅsitÄs. See porous, -ity ].
Porosity. Porosity (Ï) is defined as the nonsolid or pore-volume fraction. ....................(2). Porosity is a volume ratio and thus dimensionless, and is usually reported as a fraction or percent. To avoid confusion, particularly when variable or changing porosities are involved, it is often reported in porosity units (1 PU = 1%).