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Wiebke S. Diestelkamp 《Designs, Codes and Cryptography》2004,33(3):187-197
An important question in the construction of orthogonal arrays is what the minimal size of an array is when all other parameters are fixed. In this paper, we will provide a generalization of an inequality developed by Bierbrauer for symmetric orthogonal arrays. We will utilize his algebraic approach to provide an analogous inequality for orthogonal arrays having mixed levels and show that the bound obtained in this fashion is often sharper than Raos bounds. We will also provide a new proof of Raos inequalities for arbitrary orthogonal arrays with mixed levels based on the same method. 相似文献
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We consider an integrated sequencing and scheduling problem arising at filling lines in dairy industry. Even when a processing
sequence is decided, still a scheduling problem has to be solved for the sequence. This incorporates typical side constraints
as they occur also in other sequencing problems in practice. Previously, we proposed a framework for general sequencing and
scheduling problems: A genetic algorithm is utilized for the sequencing, incorporating a problem specific algorithm for the
fixed-sequence scheduling. In this paper, we investigate how this approach performs for filling lines. Based on insights into
structural properties of the problem, we propose different scheduling algorithms. In cooperation with Sachsenmilch GmbH, the
algorithm was implemented for their bottleneck filling line, and evaluated in an extensive computational study. For the real
data from production, our algorithm computes almost optimal solutions. However, as a surprising result, our simple greedy
algorithms outperform the more elaborate ones in many aspects, showing interesting directions for future research. 相似文献
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Anaïs Giustiniani Philippe Gugan Manon Marchand Christophe Poulard Wiebke Drenckhan 《Macromolecular rapid communications》2016,37(18):1527-1532
Macrocellular silicone polymers are obtained after solidification of the continuous phase of a poly(dimethylsiloxane) emulsion, which contains poly(ethylene glycol) drops of sub‐millimetric dimensions. Coalescence of the liquid template emulsion is prohibited by a reactive blending approach. The relationship is investigated in detail between the interfacial properties and the emulsion stability, and micro‐ and millifluidic techniques are used to generate macrocellular polymers with controlled structural properties over a wider range of cell sizes (0.2–2 mm) and volume fractions of the continuous phase (0.1%–40%). This approach could easily be transferred to a wide range of polymeric systems.
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Molecularly imprinted polymers (MIP) combine the selectivity of immunoaffinity chromatography with the robustness of common solid-phase extraction in what is referred to as molecularly imprinted solid-phase extraction (MISPE). This contribution shows how MIP design may be guided by pharmacophore modeling for the example of citrinin, which is an emerging mycotoxin from cereals. The obtained pharmacophore model allowed searching public databases for a set of citrinin-mimicking molecular surrogates. Imprinted and non-imprinted polymers were subsequently obtained through bulk and core-shell polymerization in the presence of these surrogates. Evaluation of their binding ability for citrinin and structurally related ochratoxin A revealed a promising MIP derived from rhodizonic acid. A protocol for MISPE of citrinin from cereals was subsequently developed and compared to immunoaffinity chromatography with respect to clean-up efficiency and recovery. 相似文献
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Axel Wehling Dr. Wiebke H. Pohl Birgit Gerke Stephan Kipp Dr. Peter J. Walla Prof. Dr. 《Chemphyschem》2008,9(2):327-331
Scanning electron microscope images show that it is easy to generate nanopores on polycarbonate membranes with well‐defined pore diameters by ion‐track perforation and subsequent magnetron sputtering with metal. The size reduction of the nanopores during sputtering with gold is a linear function of time. Images of different angles and from the bottom side of the membrane show that the channels are the smallest very close to the surface of the metal layer, have a conelike shape, and reach about half as much into the polymer membranes as the metal‐layer thickness. This topographical pore shape is ideal for use as optically coherent near‐field sources in deep‐nulling microscopy. We present the first results of significantly improved nulling stabilization in the presence (<2 nm optical pathway difference) and the absence (<0.6 nm optical pathway difference) of the nanoapertures in the focal region of a deep‐nulling microscope. 相似文献