An autonomous floor-cleaning robot comprises a self-adjusting cleaning head subsystem that includes a dual-stage brush assembly having counter-rotating, asymmetric brushes and an adjacent, but independent, vacuum assembly such that the cleaning capability and efficiency of the self-adjustable cleaning head subsystem is optimized while concomitantly minimizing the power requirements thereof. Also provided are composite materials comprising a porous support and a porous nanoweb. and a skin of thermoplastic polymeric material around said sealant composition. The nitrogen of the nitrogen-containing layer is dispersed within the oxide region. The plant light ends, which are normally utilized as fuel gas streams are the primary feeds to the SMR Unit along with the tail gas purge from a gasification complex within the facility. The copper member is sealed to a ceramic cylinder via metal flanges.