The air permeability specific surface of a powder material is a single-parameter measurement of the fineness of the powder. The specific surface is derived from the resistance to flow of air (or some other gas) through a porous bed of the powder. The SI units are m2·kg−1 ("mass specific surface") or m2·m−3 ("volume specific surface").
Read more about Air Permeability Specific Surface: Significance, Methods
Famous quotes containing the words air, specific and/or surface:
“What did it matter where you lay once you were dead? In a dirty sump or in a marble tower on top of a high hill? You were dead, you were sleeping the big sleep, you were not bothered by things like that. Oil and water were the same as wind and air to you.”
—Raymond Chandler (1888–1959)
“The more specific idea of evolution now reached is—a change from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity, accompanying the dissipation of motion and integration of matter.”
—Herbert Spencer (1820–1903)
“All the aspects of this desert are beautiful, whether you behold it in fair weather or foul, or when the sun is just breaking out after a storm, and shining on its moist surface in the distance, it is so white, and pure, and level, and each slight inequality and track is so distinctly revealed; and when your eyes slide off this, they fall on the ocean.”
—Henry David Thoreau (1817–1862)