Abstract: A lighting unit (100) for a medical luminaire (150) has a number of groups of LEDs (110, 110?, 110?) that are connected to a common planar printed circuit board (115). Each LED (112, 112?) of at least one of the groups (110, 110?) is associated with a respective optic (122, 122?) by which a respective LED-optic pair (120, 120?) is formed. The respective optics, based on the structure (328), specify a tilt angle (125) of a central light beam axis (124, 124?) of an emitted light beam of the LED optics pair in a tilt direction (627) of the respective LED optics pair. The tilt direction is defined such that the respective light beam axes of the emitted light beams of the LED optics pairs from the at least one group of LEDs are at least partially skewed in pairs with respect to one another.

Abstract: A lighting unit (100) for a medical luminaire (150) has a number of groups of LEDs (110, 110?, 110?) that are connected to a common planar printed circuit board (115). Each LED (112, 112?) of at least one of the groups (110, 110?) is associated with a respective optic (122, 122?) by which a respective LED-optic pair (120, 120?) is formed. The respective optics, based on the structure (328), specify a tilt angle (125) of a central light beam axis (124, 124?) of an emitted light beam of the LED optics pair in a tilt direction (627) of the respective LED optics pair. The tilt direction is defined such that the respective light beam axes of the emitted light beams of the LED optics pairs from the at least one group of LEDs are at least partially skewed in pairs with respect to one another.

Abstract: Aminonaphthalene derivatives are prepared by reacting the corresponding naphthol derivative with ammonia or amines in the presence of bisulfites. The reaction is carried out in a continuous procedure in reaction apparatus which consists wholly or partly of titanium or a titanium alloy, carbon largely excluded. Suitable alloys are titanium/palladium, titanium/nickel or titanium/molybdenum.

Abstract: Tetramethylethylenediamine is prepared by reacting 1,2-dichloroethane with an excess of dimethylamine at elevated temperatures and pressures. The process is carried out continuously in the presence of water and the amines in the reaction product are liberated by treatment with bases. Unconverted dimethylamine is separated and treated with water and then recycled into the reaction.

Abstract: Polyethylene-polyamine salts of low viscosity and high retention action, are prepared by subjecting polyethylene-polyamine salts of higher viscosity to a thermal degradation by heating their aqueous solutions in closed reaction vessels to temperatures of 100.degree. to 180.degree. C under pressures of 2 to 10 atmospheres.