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The influence of the operating frequency, the milling ball and grinding stock filling degree, the material of the milling balls and beakers, the milling ball diameter and the size of the milling beakers on the temperature increase inside the milling beakers in a mixer ball mill was investigated. These parameters influence the temperature progression and the equilibrium temperature of the system. The grinding stock filling degree with regard to the void volume in the milling ball package showed huge influence on the heating rate and the equilibrium temperature. In this context, the behavior of the temperature progression changes if the complete void volume is filled with the grinding stock.

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A number of anaerobic and aerobic bacterial species are known to decolourise azo dyes through the reduction of the azo bonds, forming the corresponding amines. In this work, we describe improved decolourisation conditions for model azo dyes by the ascomycete yeast Candida zeylanoides. The dyes were derived from the diazonium salts of metanilic and sulfanilic acids and N,N-dimethylaniline or 2-naphthol as coupling components. Total decolourisation times observed in culture media supplemented with 0.2mM dye ranged from 40 go 60 hours. The initial decolourisation rates were 14-52μmol.(g dry cell) -1 .h -1 , depending on dye structure. In the course of decolourisation either metanilic acid or sulfanilic acid were detected in the supernatant fluid, showing that decolourization by this yeast strain is due to azo bond reduction. None of those aminobenzenesulphonates supported microorganism growth as carbon and energy source but both could be used, to a limited extent, as nitrogen sources. The azo reductase activity is not significantly affected by pre-adaptation of the microorganism to the dyes.

Durch Erhitzen von Al2O3 in einer B2O3‐Schmelze auf 1000 bzw. 1100 ° C konnten die Aluminiumborate 2 Al2O3 · B2O3 bzw. 9 Al2O3 · 2 B2O3 hergestellt werden. Einige physikalischen Daten beider Verbindungen werden angegeben. Während 2 Al2O3 · B2O3 bisher noch nicht beschrieben wurde, war 9 Al2O3 · 2 B2O3 bereits bekannt; es wurde jedoch in der vorliegenden Arbeit in einer anderen Modifikation erhalten.