Location data that corresponds to one or more user devices each associated with a user may be obtained. A gate positioned within airflow opening pivots between open and closed positions, allowing a maximum and minimum amount of airflow, respectively, through the airflow opening. The memory track may be stacked on a substrate to form a multi-stack. An envelope follower is applied to the perceptual response, from which indications that the video contains visual stress scenes may be generated. A flow distributor apportions solution flow to the tube bundle and to a second solution flow path which bypasses the tube bundle but which is likewise heated by the combustion occurring within the inner shell.