Abstract: The present invention relates to a process for reducing the total organic carbon (TOC) in an aqueous mixture M1 obtained as wastewater from a process for the preparation of an olefin oxide, the process for reducing the TOC comprising: (a) contacting the mixture M1 which contains at least one oxygenate having from 1 to 16 carbon atoms with an adsorbing agent and adsorbing at least a portion of an oxygenate at the adsorbing agent; (b) separating an aqueous mixture M2 from the adsorbing agent, the mixture M2 being depleted of the oxygenate adsorbed in (a); and (c) separating an oxygenate from the mixture M2 obtained in (b) by subjecting the mixture M2 to reverse osmosis in at least one reverse osmosis unit containing a reverse osmosis membrane obtaining an aqueous mixture M3 being depleted of this oxygenate.

Abstract: Semiconductor layer structure and a method for producing a structure are provided, including a substrate made of semiconductor material, on which a layer made of a second semiconductor material is situated, furthermore a region (3) enriched with impurity atoms, which region is situated either in layer (2) or at a specific depth below the interface between layer (2) and substrate (1), additionally a layer (4) within the region (3) enriched with impurity atoms, which layer comprises cavities produced by ion implantation, furthermore at least one epitaxial layer (6) applied to layer (2) and also a defect region (5) comprising dislocations and stacking faults within the layer (4) comprising cavities, the at least one epitaxial layer (6) being largely crack-free, and a residual strain of the at least one epitaxial layer (6) being less than or equal to 1 GPa.

Abstract: The invention relates to a semiconductor layer structure of a monocrystalline silicon carbide layer on a ?150 mm diameter silicon wafer, the silicon carbide layer having a surface roughness of at most 0.5 nm RMS and a micropipe density of at most 1 cm?2 and being free of defects produced during crystal growth or epitaxial deposition, and to a process for producing such a semiconductor layer structure, by implanting carbon ions into a silicon wafer, heat treating the silicon wafer to produce a buried monocrystalline silicon carbide layer and flanking noncrystalline transition regions, followed by removing the upper silicon layer and noncrystalline transition region above the monocrystalline silicon carbide layer, thus uncovering the monocrystalline silicon carbide layer, and chemical mechanical planarizing the monocrystalline silicon carbide layer to a surface roughness of less than 0.5 nm RMS.

Abstract: The present invention relates to a liquid phase process for preparing an olefin oxide from an olefin in a cascade of two or more reactors, in a baffled tank reactor or in a plug flow reactor which process comprises the steps of a) contacting the olefin in a solvent with oxygen or an oxygen-containing gas in a first reactor of the reactor cascade or in a first stage of the baffled tank reactor or of the plug flow reactor, thereby producing a mixture comprising olefin oxide, non-converted olefin, solvent and by-products and b) transferring at least a portion of the mixture obtained in step a) to a second reactor of the reactor cascade or to a second stage of the baffled tank reactor or plug flow reactor, adding an additional amount of i) oxygen or an oxygen-containing gas and/or ii) olefin to the mixture and continuing the reaction.