Abstract: A microtunnelling apparatus and system that includes an external drive system having rotational and linear thrust drive means, a drill head section having drill rotor and drill rod and connecting to intermediate drill rods allowing extension of the boring hole created by the drill head section driven by the drive system. The drill head includes a modular construction having a plurality of circular disc like elements, a bearing module, a steering module, a spacer module, and a mounting module, for axial alignment and abutment and mounting within a cylindrical steering shell. Directional steering of the drill head includes a plurality of substantially radially extending channels in steering module, each with an hydraulically movable protuberance movable by control means to redirect the outer steering casing and thereby redirect the drill head section mounted on the distal end of the drill rods.

Abstract: A process for removing DOC (dissolved organic carbon) from a concentrated salt solution containing DOC by contacting the salt solution with a coagulant/flocculant such that the DOC becomes insoluble and removing the insoluble DOC from the salt solution.

Abstract: The present invention relates to epoxy resin compositions and in particular to curing agents for such resin compositions. The present invention thus embraces monotertiarymonosecondarydiprimarytetramines and the precursor from which this amine is manufactured namely monotertiarymonosecondarydinitrilodiamines.

Abstract: High molecular weight radiation curable ester-diethers, ester-monoethers and their diisocyanate derivatives.

Abstract: Phenyl isocyanate derivatives of oligomers, derived from polyhydroxy aliphatic hydrocarbons, formaldehyde and acrylamide, which cure upon exposure to radiation to films which retain electrical charges.