Abstract: A boiler has a shell surrounding a vertical centerline. The shell defines an inner surface having an inner diameter and an inner length extending between an upper upstream end and a lower downstream end. The inner surface defines a hollow interior, the boiler having a pre-combustion zone, a combustion zone downstream from the pre-combustion zone, and a post-combustion zone downstream from the combustion zone. The shell is tapered outward along its length in at least a portion of the combustion zone. An oxidizer inlet is in fluid communication with the pre-combustion zone, and a fuel nozzle introduces fuel into the combustion zone. A tube assembly is mounted in the hollow interior of the shell for transferring heat to fluid flowing through the tube assembly. A flue duct is in fluid communication with the post-combustion zone for transporting flue gases from the hollow interior.

Abstract: In the sliding surface of a magnetic head to a magnetic tape, the center of a magnetic gap G is offset to the center CL of a core width so that the overwrite edge Ga of the magnetic gap G approaches the center CL of the core width. As a result, the data track left to a magnetic tape by overwrite is recorded with the portion of a magnetic head which is located at the center of cores and in good touch with the magnetic tape, whereby the recorded pattern of the data track is stable and the variation of a reproduced output can be suppressed.