The aim of this work was to obtain more detailed insight into the role of Au-support interactions in the creation of catalytic performance of Au/Ce0.75Zr0.25O₂ in CO oxidation. The Ce0.75Zr0.25O₂ oxide and Au/Ce0.75Zr0.25O₂ catalysts were synthesized, characterized by BET, XRD, HRTEM, AAS, TPR-H₂, and tested in CO oxidation. An approximate evaluation of H₂ consumption for the surface reduction of the studied samples was estimated, applying the model developed by Johnson and Mooi, based on the qualitative relationship between the magnitude of the capping oxygen and BET surface area.
The toxicity of 5 new cationic surface active substances (CSAS) - imidazolium chlorides against freshwater organisms - was evaluated. Tests were conducted with the green algae Scenedesmus quadricauda, the fish Lebistes reticulatus and the crustacean Daphnia magna. European Classification was used for the evaluation of adverse effects of investigated preparations. Two of them were classified as very toxic, the others were toxic. For genotoxic effect evaluation Bacillus subtilis rec-assay was performed. It was shown that none of the examined surfactants possessed genototoxic properties.
The usefulness of fungus culture filtrates and fusaric acid as selecting agents for Fusarium resistance breeding in tulip was examined on in vitro cultures of shoots and embryonic calli of seven tulili genotypep differing in resistance to Fusarium oxysporum Schlecht, f. sp. tulipae Apt. (F.o.t.) and four virulent F.o.t. isolates. Fusaric acid influenced the shoot growth of all cultivars tested in a similar way, irrespectively of their greenhouse resistance to basal rot. Also, the sensitivity of calli of the cultivars studied to fusaric acid did not correspond with their resistance to F.o.t. evaluated in the greenhouse screening. The phytotoxity of F.o.t. culture filtrates did not depend on their fusaric acid contents. There was a negative correlation between cultivar's resistance to F.o.t in greenhouse tests and the sensitivity of their shoots to fungus culture filtrates in in vitro tests. This indicates that defence mechanism against F.o.t. in tulip tissue may have a nature of hypersensitive response. Considering the results of our study, it may be concluded that the use of fusaric acid or fungus culture filtrates for the in vitro selection of somaclones resistant to F.o.t. in tulip is not feasible.