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Influence of face velocity on the size-dependent filtration performances of the filter materials: (a) N95 and Brew rite coffee filters (3 layers) and (b) household air filter (3000 MPR, 4 layers) and 600 thread count pillowcases (4 layers). L, M, and H correspond to face velocities of 9.2, 15.3, and 23.2 cm s−1.
