Abstract: One aspect relates to a process for the preparation of a quartz glass body. The process includes providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, and making a quartz glass body out of at least part of the glass melt. The size of the quartz glass body is reduced to obtain a quartz glass grain. The quartz glass body is processed to make a preform and an opaque quartz glass body is made from the preform. One aspect further relates to an opaque quartz glass body which is obtainable by this process. One aspect further relates to a reactor and an arrangement, which are each obtainable by further processing of the opaque quartz glass body.

Abstract: An infrared emitter is provided. The infrared emitter includes a substrate made of an electrically insulating material. The substrate includes a surface that contacts a printed conductor made of a resistor material that is electrically conducting and generates heat when current flows through it. The electrically insulating material includes an amorphous matrix component into which an additional component is embedded that absorbs in the spectral range of infrared radiation. At least a part of the surface is configured with a cover layer made of porous glass, whereby the printed conductor is embedded, at least in part, in the cover layer.

Abstract: A process for the production of a porous carbon product. The process includes the steps of (a) providing a substrate surface; (b) depositing silicon dioxide as a layer on the substrate surface, thereby obtaining a porous silicon di-oxide material; (c) contacting the porous silicon dioxide material on the substrate surface with a first carbon source thereby obtaining a first precursor comprising the porous silicon dioxide material and the first car-bon source; (d) heating the first precursor thereby obtaining a second precursor comprising the porous silicon dioxide material and carbon; and (e) at least partially removing the silicon dioxide in the second precursor, thereby obtaining the porous carbon product. Also disclosed are a porous carbon product and a device that uses a porous carbon product.

Abstract: One aspect relates to a process for the preparation of a quartz glass body. The process includes providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, and making a quartz glass body out of at least part of the glass melt. The size of the quartz glass body is reduced to obtain a quartz glass grain. The quartz glass body is processed to make a preform and an opaque quartz glass body is made from the preform. One aspect further relates to an opaque quartz glass body which is obtainable by this process. One aspect further relates to a reactor and an arrangement, which are each obtainable by further processing of the opaque quartz glass body.

Abstract: An infrared emitter is provided. The infrared emitter includes a substrate made of an electrically insulating material. The substrate includes a surface that contacts a printed conductor made of a resistor material that is electrically conducting and generates heat when current flows through it. The electrically insulating material includes an amorphous matrix component into which an additional component is embedded that absorbs in the spectral range of infrared radiation. At least a part of the surface is configured with a cover layer made of porous glass, whereby the printed conductor is embedded, at least in part, in the cover layer.

Abstract: A low cost method for producing a mechanically and thermally stable composite body containing a first layer of a material with a high silicic acid content and an additional component connected to a second layer of a material with a high silicic acid content and an additional component in a second concentration differing from the first concentration is provided. The method involves (a) preparing a first slurry layer having a free surface using a first shirt mass containing SiO2 particles and an additional component dispersed in a first dispersing agent, (b) providing a second slurry mass containing SiO2 particles and an additional component in a second concentration dispersed in a second dispersing agent, (c) forming a composite-body intermediate product by applying the second slurry mass to the free surface of the first slurry layer, and (d) heating the composite-body intermediate product while forming the composite body.

Abstract: In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm3, and at a temperature of 1000° C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 ?m.

Abstract: In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm3, and at a temperature of 1000° C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 ?m.

Abstract: A method is provided for operation a field effect transistor arrangement, the field effect transistor arrangement having a planar channel layer including a semiconductor material, a whole surface of an underside of the planar channel layer being applied to a top side of an electrically insulating substrate layer and an upper side of the planar channel layer being covered by an electrically insulating electrode insulation layer, the arrangement having a source electrode disposed by a first side edge of the planar channel layer and having a drain electrode disposed by a second side edge of the planar channel layer, and having a control electrode arranged above the planar channel layer between the source electrode and the drain electrode, wherein an adjusting electrode is arranged on an underside of the substrate layer, and a first contact region between the source electrode and the planar channel layer and a second contact region between the drain electrode and the planar channel layer are each a Schottky barri

Abstract: A low cost method for producing a mechanically and thermally stable composite body containing a first layer of a material with a high silicic acid content and an additional component connected to a second layer of a material with a high silicic acid content and an additional component in a second concentration differina from the first concentration is provided. The method involves (a) preparing a first slurry layer having a free surface using a first shirt mass containing SiO2 particles and an additional component dispersed in a first dispersing agent, (b) providing a second slurry mass containing SiO2 particles and an additional component in a second concentration dispersed in a second dispersing agent, (c) forming a composite-body intermediate product by applying the second slurry mass to the free surface of the first slurry layer, and (d) heating the composite-body intermediate product while forming the composite body.

Abstract: A field effect transistor arrangement having as planar channel layer comprises semiconductor material, the whole surface of the underside of the layer being applied to an upper side of an electrically insulating substrate layer and the upper side of the planar channel layer being covered by an insulation layer. The arrangement has a source electrode on a first side edge of the channel layer and a drain electrode on a second side edge of the channel layer and a control electrode arranged above the channel layer. An adjusting electrode is arranged on an underside of the substrate layer. A contact region between the source and drain electrodes and the planar channel layer is in each case configured as a midgap Schottky barrier. A respective barrier control electrode is arranged in the vicinity of the contact region of the source electrode and of the drain electrode, Each barrier control electrode can have a section that projects outwards in the direction of the planar channel layer.

Abstract: In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm3, and at a temperature of 1000° C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 ?m.