Glossary - Introduction to Carbon Capture and Sequestration - page 554

Concurrent fl ow

Flow pattern in which the two fl ows run parallel to each other and in the
same direction.
See also countercurrent fl ow.

Countercurrent fl ow

Flow pattern in which the two fl ows run parallel to each other but in
opposite directions.
See also concurrent fl ow.

Darcy's law

Gives the relation between the fl ux of matter through a porous media and
the pressure:

k

j = −∇ p ,

m

where ∇ p is the pressure gradient, µ the viscosity of the fl uid, and k is the

permeability of the rock.

Darken-corrected diffusion coeffi cient

See Maxwell-Stefan diffusion coeffi cient. See also collective diffusion
coeffi cient.

Direct air capture

Process by which CO 2 is removed directly from the air.

Diurnal cycle

Daily cycle. In this topic, the diurnal cycle refers to the daily photosynthe-
sis cycle of plants.