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.

Electron spin resonance study of electron localization and dynamics in metal?molten salt solutions: comparison of M?MX and Ln?LnX3 melts (M = alkali metal, Ln = rare earth metal, X = halogen)

Abstract: We have studied the electron spin resonance (ESR) spectra in liquid K–KCl and M–(NaCl/KCl)eut mixtures at different concentrations in salt-rich melts approaching the metal–nonmetal transition region. In both systems F-centre-like characteristics are found. Strongly exchange narrowed signals clearly indicate that fast electron exchange occurs on the picosecond timescale. In contrast, the ESR spectra of a (NdCl2)(NdCl3)–(LiCl/KCl)eut melt are characterized by a large line width of the order of 102 mT which decreases with increasing temperature. In this case, the g-factor and correlation time are consistent with the model of intervalence charge transfer, which is supported by recent conductivity and optical measurements. The different transport mechanisms will be discussed.

Investigations on the Interaction of LCF and Oxidation

Abstract: In LCF-tests the behaviour of protective oxide scales and the first stages of materials damage in the subsurface zone after oxide scale cracking have been investigated. The tests have been performed with Ni 99.2 and Alloy 800 at 300°C and with a 9.5 Cr-steel at 650°C. Concerning oxide scale cracking tensile periods in LCF-deformation are more critical than compressive periods. The strains to scale damage are given in the paper. For Alloy 800 it has been found that the time of preoxidation decides on the beginning of surface crack initiation in the metal. This could be referred to the change of the Cr-content in the subsurface zone due to oxide scale formation and to subsequent Cr-rediffusion from the bulk material. The Cr-content in the subsurface zone decides on whether a protective chromia or a non-protective Fe-rich scale is formed during scale crack healing. For the 9.5 Cr-steel preoxidation and LCF-deformation lead to marked Cr-depletion in the subsurface zone and by this to the formation of non-protective Fe-rich oxide during scale crack healing.

Use of coarse granules of layered silicates as adsorbents for proteins

Abstract: 1. The use of coarse-grain layer silicates - prepared by dropwise addition of a suspension of a layer silicate to an aqueous polymer solution, dropwise addition of the resulting suspension to an electrolyte solution and recovery of the grains or beads formed - as adsorbents for proteins.

Selective Monoacylation of Diols by Substrate Assisted Catalysis in T40A Candida antarctica Lipase B

Abstract: The selectivity towards diols over monoesters in the esterification of diols catalysed by lipase B from Candida antarctica (CALB) was improved by the single point mutation T40A in the enzyme’s oxyanion hole. Substrate-assisted catalysis was suggested from molecular modelling of the tetrahedral intermediate in esterification of 1,2-ethanediol catalysed by T40A CALB. The non-reacting hydroxyl group of the diol forms a hydrogen bond to the oxyanion in the transition state, replacing that deleted in mutation. Monoester yields in transacylation reactions were monitored over time to compare the selectivities for wild-type and T40A CALB. The results showed increased selectivities towards the diols tested over their corresponding monoesters as a result of the T40A mutation with substrate-assisted catalysis as a plausible explanation.

Energielösungen für die Zukunft? Weiße Biotechnologie

Abstract: Angesichts hoher Olpreise und der sich abzeichnenden globalen Klimaveranderungen erscheinen biotechnisch hergestellte Energietrager als vielversprechende Zukunftsoption. Mit seinen Jahresproduktionsmengen von 2 Mio t Biodiesel, 560.000 t Bioethanol und seinen 2.700 Biogasanlagen befindet sich Deutschland in Sachen Bioenergie in der vorderen Halfte der Industrienationen. Vorgestellt werden die Moglichkeiten, die die weise Biotechnologie zur Herstellung von Energietragern bietet. In view of the high price of oil and the emerging global climate changes, biotechnologically produced energy sources appear to be a promising option for the future. Of the industrial nations, Germany with annual production figures of 2 m tons of biodiesel, 560,000 tons of bioethanol and some 2,700 biogas plants is in the upper half of the bioenergy rankings. Here, the potential of industrial biotechnology for energy production is presented in detail.