Abstract: The invention relates to a method for activating a photocatalytically active, for example titanium-dioxide-containing, outer layer (13; 23) deposited on a composite, by means of at least one element (14; 24) generating a radiation, for example for generating ultraviolet radiation. The following method steps are comprised here: •a) forming the at least one radiation-generating first element (14; 24) within the composite; •b) forming at least one sensor (16; 26) within the composite; •c) recording an actual value of a physical variable characterizing luminous radiation by means of the at least one sensor (16; 26), wherein the luminous radiation is emitted by a light-generating second element (15; 25); •d) comparing the recorded actual value with a first threshold value within an evaluation device and switching on the at least one radiation-generating first element (14; 24) if the actual value is below or above the first threshold value.

Abstract: A method may be provided for inactivating biologically active components in a liquid using low-energy electrons generated by an electron source, the electrons having an acceleration voltage of 25 keV to 300 keV. The method comprises the following steps: a) filling a vessel with a liquid volume; b) applying low-energy electrons to a first partial volume of the liquid filled into the vessel, wherein the first partial volume is a maximum of 10% of the liquid volume in the vessel; c) mixing the first partial volume of the liquid, applied with the low-energy electrons, to the second partial liquid volume in the vessel, which has not been applied with low-energy electrons; d) repeating steps b) and c) several times.

Abstract: A method may be provided for stimulating the growth of a biomass, which is mixed with a liquid inside a bioreactor, by means of ionising radiation. The following method steps are used: a) exposing a first partial volume of the liquid in the bioreactor to ionising radiation, the first partial volume comprising at most 10% of the liquid volume in the bioreactor; b) mixing the first partial liquid volume, which has been exposed to ionising radiation, with the second partial liquid volume, which has not been exposed to ionising radiation, in the bioreactor; c) repeating method steps a) and b) multiple times, each partial volume of the liquid in the bioreactor being exposed to a total radiation dose of at most 50 Gy on statistical average.

Abstract: A method is provided for activating a photocatalytically active, for example titanium-dioxide-containing, outer layer deposited on a composite, by means of at least one element generating a radiation, for example for generating ultraviolet radiation. The method may include: forming the at least one radiation-generating first element within the composite; forming at least one sensor within the composite; recording an actual value of a physical variable characterizing luminous radiation by means of the at least one sensor, wherein the luminous radiation is emitted by a light-generating second element; comparing the recorded actual value with a first threshold value within an evaluation device; and switching on the at least one radiation-generating first element if the actual value is below or above the first threshold value.