DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Exhaust gas purification using immobilised monocultures (biocatalysts)

Abstract: The paper is concerned with the purification of exhaust gases using biocatalysts in a trickle bed reactor. Substance specific strains (monocultures) which were, for example, immobilised on activated carbon served as biocatalyst. Technically important solvents and substances such as aldehydes, methyl ethyl ketone and ethyl acetate were used as pollutants. Their concentration was about 5–40 ppm in the exhaust gas to be purified. The experiments show that with suitable bacterial, strains space velocities of about k *=1500 h-1 can be obtained at a conversion of 90%. The mass transfer through the liquid film around the activated carbon grains seems to be rate determining.

Mechanical Properties of Oxide Scales on Mild Steel at 800 to 1000°C

Abstract: In the hot-rolling process of steels the oxide scales play a key role with regard to surface quality of the sheet. Therefore, a quantitative knowledge of the mechanical properties of oxide scales at rolling temperature can provide a significant improvement of sheet quality. In the present paper the mechanical properties of the oxide scales formed on mild steel were investigated in 4-point bend tests at 800, 900, and 1000°C in dry air, humid air (7–19.5 vol.% H2O) and laboratory air at different deformation rates. It turns out that the environment has a significant influence on scale thickness and structure as well as on adhesion of the oxide scales. The mechanical measurements show plastic-creep deformation of the oxide scales. Water vapor did not have any significant effect on the creep properties of the oxide scales. In the measurements the secondary-creep-stress values of the oxide were determined as a function of the strain rate and plotted into an Ashby map for FeO. This plot can serve for an extrapolation of the data for even higher strain rates as relevant for the hot-rolling process.

Partial Methylation at Am100 in 18S rRNA of Baker's Yeast Reveals Ribosome Heterogeneity on the Level of Eukaryotic rRNA Modification

Abstract: Ribosome heterogeneity is of increasing biological significance and several examples have been described for multicellular and single cells organisms In here we show for the first time a variation in ribose methylation within the 18S rRNA of Saccharomyces cerevisiae Using RNA-cleaving DNAzymes, we could specifically demonstrate that a significant amount of S cerevisiae ribosomes are not methylated at 2′-O-ribose of A100 residue in the 18S rRNA Furthermore, using LC-UV-MS/MS of a respective 18S rRNA fragment, we could not only corroborate the partial methylation at A100, but could also quantify the methylated versus non-methylated A100 residue Here, we exhibit that only 68% of A100 in the 18S rRNA of Scerevisiae are methylated at 2′-O ribose sugar Polysomes also contain a similar heterogeneity for methylated Am100, which shows that 40S ribosome subunits with and without Am100 participate in translation Introduction of a multicopy plasmid containing the corresponding methylation guide snoRNA gene SNR51 led to an increased A100 methylation, suggesting the cellular snR51 level to limit the extent of this modification Partial rRNA modification demonstrates a new level of ribosome heterogeneity in eukaryotic cells that might have substantial impact on regulation and fine-tuning of the translation process

Chemoenzymatic Halogenation of Phenols by using the Haloperoxidase from Curvularia inaequalis

Abstract: The vanadium-​dependent chloroperoxidase from Curvularia inaequalis is an efficient biocatalyst for the in situ generation of hypohalous acids and subsequent electrophilic oxidn.​/halogenation reactions. Esp., its superb activity and stability under operational conditions make it an attractive catalyst for org. synthesis. Herein, the efficient bromination of thymol was investigated, and turnover nos. of the enzyme were found to exceed 2 000 000. The major novelty of the work is that vanadium chloroperoxidase is more useful as a brominating enzyme than vanadium bromoperoxidase in terms of operational stability, besides being far more stable than heme-​contg. peroxidases.