Abstract: Apparatus and methods are disclosed which apply inorganic particles to a plugged honeycomb body comprising porous walls, an inlet end and an outlet end. The apparatus comprises a particle counter and the method comprises counting a selected portion of the inorganic particles from a first sampling port upstream from the plugged honeycomb body and a second sampling port downstream from the plugged honeycomb body. The selected portion of the inorganic particles are in a preselected inorganic particle size range. Filtration efficiency can be determined while inorganic particles are being deposited, for example to increase filtration efficiency.

Abstract: Apparatus and methods are disclosed which apply inorganic particles to a plugged honeycomb body comprising porous walls, an inlet end and an outlet end. The apparatus comprises a particle counter and the method comprises counting a selected portion of the inorganic particles from a first sampling port upstream from the plugged honeycomb body and a second sampling port downstream from the plugged honeycomb body. The selected portion of the inorganic particles are in a preselected inorganic particle size range.

Abstract: An architectural building block including a generally triangular block having an outer wall, an inner wall disposed in substantially parallel configuration with respect to the outer wall and three side walls, each adjoining the outer wall and the inner wall. One of the side walls includes dual inverse mirror planes and each of the other two of which includes a single inverse mirror plane. At least one the side walls is configured to be positionable so as to mate with a side wall of an abuttingly disposed block, whereby curved structures may be constructed from a plurality of such blocks to form a dihedral angle between each set of two blocks. In one embodiment, the inner wall further includes at least one depression disposed on the inner wall of the block.

Abstract: An architectural building block including a generally triangular block having an outer wall, an inner wall disposed in substantially parallel configuration with respect to the outer wall and three side walls, each adjoining the outer wall and the inner wall. One of the side walls includes dual inverse mirror planes and each of the other two of which includes a single inverse mirror plane. At least one the side walls is configured to be positionable so as to mate with a side wall of an abuttingly disposed block, whereby curved structures may be constructed from a plurality of such blocks to form a dihedral angle between each set of two blocks. In one embodiment, the inner wall further includes at least one depression disposed on the inner wall of the block.