Abstract: A process for controlling heat output of a heating device, such as an auxiliary heating device for a vehicle, and a switching arrangement for performing such process. The governing value in controlling the heat output is the temperature gradient with respect to time during heating of a heat exchange medium between two temperature threshold values. The threshold values are empirically determined and prespecified. The operating condition of the heating device is regulated in dependence upon the slope of the temperature gradient which is determined, preferably, based upon the time for heat-up of the heat exchange medium. The heat-up time is measured with the aid of a timer, and the heating time thus measured is compared with predetermined, prespecified values therefor.

Abstract: A method of making a retained tab for a container end and a design for same are disclosed. The tab opens in such a way that multiple forms of stress are induced in the tab before the tab will break away from the end. Specifically, the tab endures first a bending stress and then a torsional stress. The mode of stress being defined by the construction of the tab.

Abstract: As a powerful attractant and trail-following substance for ants of the type of the Pharaoh's ant (Monomorium Pharaonis L) which is active in amounts of between 10.sup.-11 and 10.sup.-5 grams has been shown to be 2-(5'-n-Hexenyl)-5-n-pentylpyrrolidine and a few of the homologues of the 5-pentyl radical. Advantageously it can be combined with the previously proposed compound 5-methyl-3-n-butyl-octahydro-indolizine.