The supply of power to a storage apparatus can be made redundant by means of power inputs from two types of power supply, namely an AC power supply and a DC power supply. The invention further relates to a process for the production thereof and use thereof, in particular for the production of rigid PURPIR foams. The invention also provides a method for using a diagnostic element, wherein the method comprises flowing sample through the diagnostic gel to provide an analyte diagnostic gel; analyzing the analyte diagnostic gel. The method further includes exposing the substrate to a gas containing at least one of molecular chlorine or a chlorine compound. The reinforcement member has a forward end fixedly attached to the sill at a front attachment point and a rearward end fixedly attached to the A-pillar at a rear attachment point that is laterally offset from the front attachment point.