Abstract: A composite porous media for either gas or liquid flow is strong and efficient, and can readily be formed in or into a wide range of different shapes and configurations. In particular, the porous media is a composite of a metal, aerogel or ceramic foam (i.e., a reticulated inter-cellular structure in which the interior cells are interconnected to provide a multiplicity of pores passing through the volume of the structure, the walls of the cells themselves being substantially continuous and non-porous, and the volume of the cells relative to that of the material forming the cell walls being such that the overall density of the intercellular structure is less than about 30 percent theoretical density) the through pores of which are impregnated with a sintered powder or aerogel. The thickness, density, porosity and porous characteristics of the final composite porous media can be varied to conform with what is demanded by the intended use.

Abstract: A composite porous media for either gas or liquid flow is strong and efficient, and can readily be formed in or into a wide range of different shapes and configurations. In particular, the porous media is a composite of a metal, aerogel or ceramic foam (i.e., a reticulated inter-cellular structure in which the interior cells are interconnected to provide a multiplicity of pores passing through the volume of the structure, the walls of the cells themselves being substantially continuous and non-porous, and the volume of the cells relative to that of the material forming the cell walls being such that the overall density of the intercellular structure is less than about 30 percent theoretical density) the through pores of which are impregnated with a sintered powder or aerogel. The thickness, density, porosity and porous characteristics of the final composite porous media can be varied to conform with what is demanded by the intended use.

Abstract: A diesel particle virtual impactor sampler provides for a total flow through a virtual impactor after the flow passes through a classifier that removes particles substantially larger than the cutoff point of the virtual impactor. The virtual impactor has two outlets, one for minor flow and one for major flow. In a preferred embodiment, filters are used for separately filtering the major and minor flows and collecting the particles carried thereby so that a determination of the concentration of particles above and below the cutoff point can be obtained. Alternately, the major and minor flows and the particles can be passed through particle analyzer instruments for a direct particle measurement of each of the flows.