Abstract: The surface of a semiconductor is prepared by electrolytically removing the surface of the semiconductor. A two component electrolyte is used. A first component forms an oxide on the surface of the semiconductor and the second component dissolves the oxide.

Abstract: An opto-electronic element consists of a dielectric optical waveguide having a single crystal core of meta-nitroaniline. The element is made by feeding molten meta-nitroaniline into a hollow fibre along which a temperature gradient exists. Nucleation sets in at one end of the fibre and the temperature gradient is altered to promote crystal growth along the fibre. The element can be used as a polarizer, in isolators, harmonic generators or mixers. The action of the device depends on either the non-linear optical properties of the meta-nitroaniline or the optical anisotropy of the meta-nitroaniline. To make a polarizer the meta-nitroaniline core is surrounded by a cladding having a refractive index lying midway between two of the refractive indices of the meta-nitroaniline.

Abstract: A process for the preparation of high gloss, high impact vinyl aromatic hydrocarbons which process comprises (1) subjecting a solution of rubber and vinyl aromatic hydrocarbon monomer to mass polymerization conditions in the presence of a chain transfer agent for a period of 4 to 10 hours until the reaction mass reaches a viscosity of 1800 to 2000 cps., said chain transfer agent being introduced into the reaction mass in two portions, a first portion representing 50 to 90% of the total chain transfer agent to be present during the mass polymerization and being added to said solution at or before the beginning of said mass polymerization and a second portion representing 10 to 50% being added just prior to the end of said mass polymerization, (2) subjecting said reaction mass to suspension polymerization conditions and (3) recovering high impact polymeric vinyl aromatic hydrocarbons having improved high gloss characteristics.