Keramische Folien (Germany)

ZusammenfassungDie meisten Kinder mit Ösophagusatresie (ÖA) haben pulmonale Probleme. Ursachen sind begleitende Fehlbildungen der zentralen Atemwege, Tracheomalazie, Intubations- und Beatmungsfolgen sowie Frühgeburtlichkeit. In der Folge kommt es zu gehäuften pulmonalen Infektionen mit bakterieller Beteiligung. Spätfolgen sind Bronchiektasen und andere strukturelle Schädigungen der Lungen, mit restriktiver Ventilationsstörung, verminderter Belastbarkeit und erhöhter Mortalität. Um pulmonale Spätfolgen zu verhindern, ist eine frühzeitige und konsequente multidisziplinäre Nachsorge und Behandlung bei Kindern mit ÖA zu fordern sowie die Fortsetzung auch im Erwachsenenalter. Nur wenige große Zentren können solche Strukturen vorhalten und die notwendige Expertise erwerben.

Abstract Eine sorgfältige überwachung und Pflege von Kühlschmierstoffen zum Beispiel in Pumpen unerlässlich. Einen wichtigen Teil der Pflege stellt die Abtrennung fester Fremdstoffe dar. Eine exzellente Möglichkeit hierzu bietet die Dynamische Crossflow Filtration (DCF) mit keramischen Filterscheiben.

The work describes a fast and flexible micro/nano fabrication and manufacturing method for ceramic Micro-electromechanical systems (MEMS)sensors. Rapid prototyping techniques are demonstrated for metal oxide sensor fabrication in the form of a complete MEMS device, which could be used as a compact miniaturized surface mount devices package. Ceramic MEMS were fabricated by the laser micromilling of already pre-sintered monolithic materials. It has been demonstrated that it is possible to deposit metallization and sensor films by thick-film and thin-film methods on the manufactured ceramic product. The results of functional tests of such manufactured sensors are presented, demonstrating their full suitability for gas sensing application and indicating that the obtained parameters are at a level comparable to those of industrial produced sensors. Results of design and optimization principles of applied methods for micro- and nanosystems are discussed with regard to future, wider application in semiconductor gas sensors prototyping.

Recently Kerafol's alliance with H.C. Starck and the commercial availability of the jointly developed high - output cells with scandium doped zirconia electrolytes was announced. Together the companies are able to provide cells possessing extraordinary performance and long term stability. The combined production facilities meet the increased demand of SOFC stack and system manufacturers. Currently the installation of test benches for MEA characterization is being prepared for quality assurance as well as for development. In addition to cell performance enhancements the emerging topic of electrolysis with solid oxide electrolysis cells (SOEC) will be examined. Because of the fluctuating availability of renewable energy the electrolysis mode of SOFCs to save energy in form of hydrogen during an overproduction and the reverse power generation during periods without wind or sun is of high interest. The first step in a new project examines the feasibility of a SOEC. The next steps include the development of reliable cells with regard to robustness and long term stability. In this paper the status quo of electrolyte supported cells as well as the development project dealing with SOEC at Kerafol is summarized. Additionally the optimization of tape cast, custom-fit glass sealants obtainable from Kerafol for both SOFC and SOEC applications is described. The efforts are focused upon quality improvement, cost reduction and industrial scale manufacturing of sealants.

Nickel oxide and yttria stabilised zirconia (NiO/YSZ) cermets have been prepared using a chemical co-precipitation of hydroxides. The influence of different factors on the microstructure, mechanical and electrochemical properties of the anode were investigated. The electrochemical tests were carried out on dense 8YSZ and 10Sc1CeSZ tapes (50x50x0.150 mm, Kerafol GmbH) with symmetrically screen-printed cathodes and anodes with a lateral dimension of 40x40 mm. The cells were sintered in co-firing. The anodes were characterized by impedance spectroscopy at open circuit potential and under current load at temperatures of 850-950{degree sign}C in hydrogen/steam atmosphere (H2:H2O=1:1). The electrode polarization resistance (Rp) of the spectra was identified and the influences of operating temperature (850{degree sign}C, 900{degree sign}C and 950{degree sign}C), current load and pH2O on impedance spectra of anode were discussed. The long-term stability of the cell with an anode prepared by co-precipitation was carried out over 1000 hours under current density of 430-450 mA/cm2@0.7V at temperature 850{degree sign}C.

The local flow behavior in a tape‐casting unit for processing ceramic slurries was investigated by laser–Doppler velocimetry (LDV). The most remarkable feature of the LDV system used was its high spatial resolution (24 μm) and temporal resolution (5 μs). A translucent Newtonian model fluid which, in the relevant processing window, at higher shear rates, exhibits a rheological behavior similar to that of a typical ceramic slurry, was chosen to determine the velocity distribution in the flow channel (i.e., in the tape‐casting unit). The flow behavior was measured directly in several particular regions of the flow channel, which substantially consisted of a double doctor‐blade assembly. The velocity distribution obtained below the forming doctor blade showed the strong influence of the casting speed on the flow behavior of the model fluid. Furthermore, the measured flow behavior was analyzed, based on the assumptions of fluid dynamics. Below the doctor blade, the flow behavior was considered to be a combination of pressure flow and drag (Couette) flow. The flow rates from the applied hydrostatic pressure and external drag forces were shown to be additive. A comparison between the measured velocity profiles and the model calculations showed excellent agreement. A flow reversal (secondary flow), never before measured quantitatively, was detected between the two inserted rectangular blades. Apparently, secondary flows influenced the surface properties of the cast green tapes.