An intake control system for an internal combustion engine is capable of ensuring a differential pressure across an EGR valve, and controlling an EGR amount with high accuracy. A refresh mechanism may allow a data warehouse to remain available to users while the data is being refreshed. Hydrochloric acid can be recovered by multi-stage evaporation. When the retention bar is in a retaining position, the flexible stops engage a substantially rigid surface of the enclosure or chassis, keeping the bar in the retaining position. A light-transmissive spire may be disposed atop one or both towers. The non-volatile elementary memory cells of the two groups are coupled firstly to a supply terminal and secondly to the outputs and to the inputs of the two inverters via a controllable interconnection stage.