Abstract: A method for identifying overheated spots in liquid-filled electrical devices, comprising the steps of: a) determining the locations of potentially overheatable spots in said device and mapping said locations; b) positioning a tag consisting of one or more chemical indicators on potentially overheatable spots in said devices, wherein when said tags are exposed to a given high temperature, they are depolymerized into thermal degradation products which are diffused into the liquid; c) identifying the thermal degradation products by analytical methods; and d) locating the overheated places according to the identified thermal degradation products and the map of locations of said tags; wherein the tags comprise polymers and copolymers, which are substantially absent from the liquid of the device at normal working conditions.

Abstract: Chemically resistant materials with high mechanical properties are provided by using polycyclocarbonates of special structure. The polycyclocarbonates are prepared by the reaction of oligocyclocarbonates containing ended epoxy groups with primary aromatic diamine.

Abstract: A method of manufacturing tiles from waste wood uses round crosscut wood slices, a binder, and a filler. The slices, all generally of a thickness, are placed on the flat bottom of a die within side walls. Adhesive is applied to the slices and the die is filled with a mixture of the binder and the filler. The die contents are hot pressed to achieve the required tile thickness. The tile is ejected from the die and then maintained at room temperature for not more than 72 hours. The face side of the tile is ground and the dimensions of the tile are brought within the required tolerances.