Abstract: The composite ceiling can have a shell made of a polymer-based material and defining a plurality of internal compartments, having a flat and smooth under surface spaced apart from a flooring and facing the flooring, and an upper surface opposite the under surface, a first layer of rebars having a first plurality of rebars spaced apart from one another along the depth of the shell, the first layer of rebars being separated from upper surface by spacers, a second layer of rebars having a second plurality of rebars spaced apart from one another along the width of the shell, the second layer of rebars being above the first layer of rebars, and a horizontally extending concrete slab extending over the shell and surrounding the rebars.

Abstract: The transformer heating unit can be transformed into six different modes, namely:a stove, a cooking oven, a roaster, a barbecue grill unit, a foodstuff smoking unit, and an indoor space heating furnace.The whole transformer unit is enclosed into a compact, box-like casing, which can be deployed into either of the six modes. In its furnace mode, its combustion gas outlet port is coupled to an exhaust flue pipe, for controlled escape of combustion gases outwardly of the room where the occupants are located, whereby smoke intoxication is prevented.

Abstract: A school desk has legs adapted to be lengthened for raising the desk. The legs are provided with a sleeve adapted to fittingly slide on the legs. The legs have a transversal perforation, and the sleeves have a set of vertically disposed holes. A screw and nut combination is used to lock the sleeves on the legs at selected vertical positions. The sleeves are vertically grooved to facilitate their sliding action and to allow the screw and nut combination to positively lock the sleeves on the legs.