Abstract: The invention relates to a hollow fiber bundle for accommodation in a mass transfer device, the hollow fiber bundle including a multitude of hollow fiber strands for heat transfer and/or mass transfer which are aligned essentially at least locally along a preferential direction and are arranged with respect to one another in relation to their local preferential directions such that at least one first group of hollow fiber strands points essentially in a first preferential direction, at least one second group of hollow fiber strands essentially in a second preferential direction and at least one third group of hollow fiber strands in essentially a third preferential direction, the three preferential directions being independent of one another.

Abstract: The invention relates to novel antimicrobial agents that are based on ?-lactam derivatives and are produced by reacting previously known ?-lactam derivatives with polyphenol oxidase substrates under the influence of free radicals and by forming salts of any ?-lactam derivatives with polyhexamethylene biguanide hydrogen carbonate. Said novel compounds are suitable as an antibiotic.

Abstract: Selective solar absorbers are prepared by coating a reflector with a thin cermet layer prepared by depositing and subsequently sintering at least one cermet layer precursor which is an aqueous or alcoholic dispersion of ceramic nanoparticles, the dispersion also containing dissolved metal ions corresponding to the desired metal in the cermet. Sintering in H2 or an inert atmosphere reduces the metal ions to elemental metal particles.