Abstract: The invention relates to a lighting unit having a concave reflector with an axis of symmetry and a light emission window bounded by a circumferential edge transverse to the axis, an elongate light source extending substantially along the axis of symmetry, which light source is accommodated in a holder opposite the light emission window, and an axially positioned cap, which cap partly surrounds the light source and forms an optical means to intercept unreflected light rays. According to the invention, the light source is surrounded by a sleeve with an end at the side of the light emission window, over which end the cap is positioned by way of a fixing element.

Abstract: The invention relates to a lighting unit having a concave reflector with an axis of symmetry and a light emission window bounded by a circumferential edge transverse to the axis, an elongate light source extending substantially along the axis of symmetry, which light source is accommodated in a holder opposite the light emission window, and an axially positioned cap, which cap partly surrounds the light source and forms an optical means to intercept unreflected light rays. According to the invention, the light source is surrounded by a sleeve with an end at the side of the light emission window, over which end the cap is positioned by way of a fixing element.

Abstract: 4-Chloro-5-amino-2-phenyl-3(2H)-pyridazinone is prepared from 4,5-dichloro-2-phenyl-3(2H)-pyridazinone and ammonia in high yield and substantially free from 4-amino-5-chloro-2-phenyl-3(2 H)-pyridazinone in a method comprising reacting 4,5-dichloro-2-phenyl-3(2H)-pyridazinone with aqueous ammonia in the presence of a catalyst which is capable of selectively exchanging the 5-chlorine atom in 4,5-dichloro-2-phenyl-3(2H)-pyridazinone with a leaving group of such a nature that the resulting intermediate compound is capable of alkylating ammonia to 4-chloro-5-amino-2-phenyl-3(2H)-pyridazinone in high yield in the reaction medium, thereby regenerating the catalyst. The end product is isolated by filtration after the reaction and washed with water, and the mother liquor plus the wash water are used as reaction medium for the next batch.

Abstract: An improved process for the production of sodium salicylate and salicylic acid from phenol at a high degree of conversion with a concomitant reduction in undesirable by-products. The process comprises reacting a sodium phenolate with carbon dioxide in a direct, single step at a temperature above about 165.degree. C. to produce directly sodium salicylate, which is then converted by conventional means to the salicylic acid.