Input reconstruction for statistical‐based fault detection and isolation

In this work, an input reconstruction scheme for detecting and isolating sensor, actuator, and process faults is proposed. The scheme uses model‐based and statistical‐based FDI methods, which yields an improved analysis of abnormal operation conditions in chemical processes. The main advantage of the proposed approach over existing works lies in the reconstruction of system inputs and the subsequent estimation of fault signatures. This advantage is demonstrated through simulation examples and the analysis of recorded process data from a reactive batch distillation column. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Cell migration and proliferation during monolayer formation and wound healing

The interaction of living cells with surfaces is important in applications of biomaterials, such as tissue engineering. Characterising and modelling the attachment, migration and proliferation of cells on materials used for tissue engineering provides valuable insight into their potential applications as well as a means of objective comparison. In this study, proliferation and migration of NIH-3T3 fibroblast cells on tissue culture plastic in vitro were quantified. The development of randomly scattered individual cells into confluent cell monolayers proceeded with cell density following a logistic growth pattern. Travelling cell wavefronts produced in a wound healing assay were modelled with a modified Fisher equation incorporating both diffusion and logistic growth. The diffusivity and growth rates thus determined could be used for comparison with cell behaviour on other surfaces or under different conditions. Cell tracking showed that the average effective velocity of cells varied inversely with cell density, supporting contact inhibition of cell movement.     

Linking Simultaneous In Situ WAXS/SAXS/Raman with Raman/ATR/UV–vis Spectroscopy: Comprehensive Insight into the Synthesis of Molybdate Catalyst Precursors

A new setup is presented which enables simultaneous wide- and small-angle X-ray scattering (WAXS/SAXS) and Raman spectroscopic experiments during the synthesis of Mo-based mixed oxide catalyst precursors at the μ-spot beamline at the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY). Furthermore, we report about the separate monitoring of the same reactions under comparable conditions by simultaneous combined ATR/UV–vis/Raman spectroscopic measurements. For testing the performance of both experimental setups two syntheses were described comprising the precipitation of metal molybdates by mixing solutions of metal nitrates and ammonium heptamolybdate. Additionally, the effect of H₃PO₄ admixture on precipitation was investigated. The combined evaluation of spectroscopic and WAXS/SAXS data allows the discrimination between different molybdate species appearing in solution and precipitate. Furthermore, these molybdate species could be assigned to separate phases of different crystallinity.     

Mechanical characterization of PEDOT:PSS thin films

By tensile testing the mechanical properties of thin films of the intrinsically conductive poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) under different relative humidities are investigated. It can be shown that the fracture behaviour strongly depends on humidity and reaches from brittle to plastic. The fracture surfaces are first investigated by scanning electron microscopy (SEM). The surfaces change from smooth at 23% rH to rough with shear lips for samples tested at 55% rH. Atomic force microscopy then reveals the topography of fracture surfaces at the nanometer scale and thus gives insights into the morphology of PEDOT:PSS thin films. By combining the experimental findings of the tensile tests and the AFM scans a micromechanical model for the deformation behavior of PEDOT:PSS can then be derived.     

Vorwort der Herausgeber

Ohne Zusammenfassung     

Thesen und Trends – Mit funktionalen Oberflächen in die Zukunft

Propositions and Trends – With Functional Surfaces into the Future Functional surfaces are the key to innovative products. Already today the properties, lifetime, and costs for most industrial and consumer products are determined by functionalised surfaces. Three Fraunhofer Institutes supported by the BMBF investigated the actual state of the art of production technology regarding functional surfaces, their future perspectives and the research and development demand. The results are published in the study “Production technology for the generation of functional surfaces” available at info@ist.‐ fraunhofer.de and the essentials are summarised in this article.