Abstract: A biodegradable diaper. The diaper has an outer sheet of biodegradable material able to resist water absorption. An inner sheet of biodegradable material is able to allow the passage of water and is attached to the outer sheet by a biodegradable adhesive at the periphery to form an envelope. A super absorbent core is located within the envelope. There is a water resistant film of biodegradable material located within the core to assist in fluid distribution into the core.

Abstract: A solar collector comprises an elongate, central conduit for fluid and a laterally concave reflective surface facing the central conduit. The central conduit extends centrally along the laterally concave surface. The surface has a shape to reflect solar radiation onto the conduit. A reflective fin is connected to the conduit and extends away from the reflective surface. The fin has a concave shape to reflect solar radiation striking the fin onto the conduit.