Abstract: Operating a gaseous fuel engine system includes detecting preignition in one or more of a plurality of cylinders based on a monitored cylinder pressure during combustion of a gaseous fuel such as a gaseous hydrogen fuel. Operating a gaseous fuel engine system also includes reducing a fuel injection amount for the one or more of the plurality of cylinders to a derated fuel injection amount that is based on a timing of the detected preignition. Fuel injection amount may be reduced to a greater relative extent if detected preignition is early, and to a lesser relative extent if detected preignition is later, in an engine cycle. Related apparatus and control logic is also disclosed.

Abstract: A radiant heating system for installation or a subfloor. Header panels having arcuate cutouts are secured on the subfloor near opposite walls of a room. Spaced apart sleepers are secured to extend between the header panels and provide channels that receive radiant heating tubing. The cutouts are initially occupied by break away header plates which can be detached to allow the tubing to curve through the cutouts so that it can extend between the ends of adjacent channels. The cutouts can be inserted back into the cutouts to secure the tubing bends in place. Heat conductive panels overlie the sleepers and channels and can be overlaid with finished flooring.

Abstract: Disclosed is a process of converting asphalt composition roofing shingles into dimensional construction products. Asphalt composition roofing shingles are de-consolidated, such as by grinding, into a crumble. The asphalt shingle crumble is processed in a manner to increase the fusibility activity of the asphalt without decomposing a substantial fractional amount of the asphalt to an ash-like brittleness. The foregoing can be achieved by heat exchange using infrared heaters as the heat source. One disclosed example trial of the process warmed the crumble to a bulk temperature of between about 130.degree. F. and 150.degree. F. Following that, the asphalt shingle crumble is compacted into the shape of a given dimensional construction product such as blocks, curbs, tiles, beams, posts, and so on. The best quality products are achieved by a two-step compaction process in which there occurs a certain time elapse between the two compaction steps.