The invention concerns a structural and mechanical means to build a large retractable roof, that can have the shape of a barrel vaulted roof or a pitched vaulted roof or a flat roof. The first antenna includes a grounding unit, a first substrate positioned on the grounding unit, a first radiating unit positioned on the first substrate, and a first feeding unit coupled to the first radiating unit. The invention further relates to genetic complements of plants of variety CH514800. The micro lenses are arranged in a series of concentric circles with regard to a center point located on an optical axis of the main lens. Each handrail is formed with a sigmoidal segment between a vertically directed upper segment and a horizontally directed lower segment, to facilitate insertion through the respective elongated slot. The semiconductor structure comprises a conductive layer, a via, and a barrier layer disposed between the conductive layer and the via.