An electric power generator includes a first conductive layer, a plurality of semiconducting piezoelectric nanostructures, a second conductive layer and a plurality of conductive nanostructures. Planting container 1 comprises box 2 with stickers 3 to carry perforated partition panel 4. The frame also serves to provide means for securing the panel onto roof trusses. In use, the plug is screwed into and out of a container wall opening, having an internally threaded portion and an unthreaded portion, the sealing gasket being compressed between the unthreaded opening portion and the plug gasket seat and lying in close proximity to the internal thread. The method may also include assigning a second Cell Identity j to a particular adjacent cell j selected from the one or more adjacent cells k such that an absolute value of i\u2212j equals \u03b4m. The web service includes information relating to the equipment.