Mullite coatings on ceramic substrates: Stabilisation of Al2O3-SiO2 suspensions for spray drying of composite granules suitable for reactive plasma spraying

The present work deals with the preparation of stable alumina + silica suspensions with high solid loading for the production of spray-dried composite powders. These composite powders are to be used for reactive plasma spraying whereby the formation of mullite and the coating on a ceramic substrate are achieved in a single step process. Electrostatic stabilisation of alumina and silica suspensions has been studied as a function of pH. Silica suspensions are most stable at basic pH whereas alumina suspensions are stable at acidic pH. The addition of ammonium polymethacrylate (APMA) makes it possible to stabilise alumina and prepare a stable 50 wt% alumina + silica suspension at pH 10. The optimum amounts of dispersant and binder have been determined by zeta potential, viscosity and sedimentation measurements. Spray drying of the suspension yields composite powders whose morphology, size distribution and flowability have been characterized before realizing reactive plasma spraying tests. (C) 2009 Elsevier Ltd. All fights reserved

Characterization of Pharmaceutical Tablets by X-ray Tomography

Solid dosage forms such as tablets are extensively used in drug administration for their simplicity and large-scale manufacturing capabilities. High-resolution X-ray tomography is one of the most valuable non-destructive techniques to investigate the internal structure of the tablets for drug product development as well as for a cost effective production process. In this work, we review the recent developments in high-resolution X-ray microtomography and its application towards different tablet characterizations. The increased availability of powerful laboratory instrumentation, as well as the advent of high brilliance and coherent 3rd generation synchrotron light sources, combined with advanced data processing techniques, are driving the application of X-ray microtomography forward as an indispensable tool in the pharmaceutical industry

Methicillin-resistant Staphylococcus aureus in Europe, 1999–2002

European Antimicrobial Resistance Surveillance System shows large variations in methicillin-resistant S. aureus

Adding new word associations to semantic memory : Evidence for two interactive learning components

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