Abstract: An object detecting device for detecting an object at least partly having a magnetic substance or magnetic-flux permeable material is formed of a detection coil arrangement including a primary coil for generating magnetic flux and a secondary coil disposed separately from the primary coil at a predetermined interval for receiving the magnetic flux from the primary coil; and a detection circuit for detecting an increase of the magnetic flux transmitted to the secondary coil due to presence of the object within a space between the primary and secondary coils. The detection circuit produces signal indicating the presence of the object upon detection of the presence.

Abstract: The invention enables the rooftop cultivation of turf which can both be walked upon and which also helps prevent temperatures from rising in rooms below the roof by shielding it from the sun. The structured cultivation medium itself comprises three layers of synthetic plastic material, a top layer for turf cultivation, a middle layer to protect the roots and a bottom layer to drain water away. A root blocking waterproofing layer is laid on the surface of the roof slab to waterproof the building and to guard against the downward encroachment of roots. A net is also laid on top of the turf both to prevent it from being damaged by wind and also protect it against concentrated loads.