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Systematic Optimization (systematic + optimization)
Selected AbstractsSystematic optimization for the evaluation of the microinjection molding parameters of light guide plate with TOPSIS-based Taguchi methodADVANCES IN POLYMER TECHNOLOGY, Issue 1 2010Te-Li Su Abstract A back light module is a key product for providing sufficient light source for a liquid crystal display (LCD). The light guide plate (LGP), used to increase the light usage rate, is a key component in the back light module. This study researches the microinjection molding process parameters and the quality performance of the LGP. Its purpose was to develop a combining Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) with the Taguchi method. This is to optimize the multiquality performance of the LGP for the injection molding manufacturing process, in which both the LCD and the LGP spontaneously produce the best quality performance for V-cut depth and angle. First, an L18 orthogonal array was planned for the manufacturing parameters that affect the microinjection molding process. These included cooling time, mold temperature, melt temperature, injection speed, injection pressure, packing pressure, packing switching, and packing time. The TOPSIS was used to deal with the single-quality optimization disadvantage of the Taguchi method. Then, the TOPSIS response table was used to obtain the optimized manufacturing parameters combination for a multiresponse process optimization. From the analysis of variance, the significant factors for the quality performance of the LGP could be obtained. In other words, by controlling these factors, it was possible to efficiently control the quality performance of the LGP. Finally, with the five verified experiments, the optimized processing parameters came within a 95% confidence interval. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:54,63, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20181 [source] Rapid Organocatalytic Aldehyde-Aldehyde Condensation ReactionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 25 2007Anniina Erkkilä Abstract We report the results of the systematic optimization of the ,-methylenation of aldehydes with aqueous formaldehyde. A simple combination of a secondary amine catalyst and a weak acid co-catalyst has been identified, allowing access to ,-substituted acroleins in a matter of minutes. In the absence of formaldehyde, the catalytic system promoted the self-condensation reaction of ,,,-unsaturated aldehydes. Both of these reactions exhibited linear relationships between co-catalyst acidities and reaction rates. A second-order dependence of catalyst concentration was observed, pointing to the involvement of two molecules of the ammonium catalyst in the rate-determining step. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] A superstructure-based optimal synthesis of PSA cycles for post-combustion CO2 capture,AICHE JOURNAL, Issue 7 2010Anshul Agarwal Abstract Recent developments have shown pressure/vacuum swing adsorption (PSA/VSA) to be a promising option to effectively capture CO2 from flue gas streams. In most commercial PSA cycles, the weakly adsorbed component in the mixture is the desired product, and enriching the strongly adsorbed CO2 is not a concern. On the other hand, it is necessary to concentrate CO2 to high purity to reduce CO2 sequestration costs and minimize safety and environmental risks. Thus, it is necessary to develop PSA processes specifically targeted to obtain pure strongly adsorbed component. A multitude of PSA/VSA cycles have been developed in the literature for CO2 capture from feedstocks low in CO2 concentration. However, no systematic methodology has been suggested to develop, evaluate, and optimize PSA cycles for high purity CO2 capture. This study presents a systematic optimization-based formulation to synthesize novel PSA cycles for a given application. In particular, a novel PSA superstructure is presented to design optimal PSA cycle configurations and evaluate CO2 capture strategies. The superstructure is rich enough to predict a number of different PSA operating steps. The bed connections in the superstructure are governed by time-dependent control variables, which can be varied to realize most PSA operating steps. An optimal sequence of operating steps is achieved through the formulation of an optimal control problem with the partial differential and algebraic equations of the PSA system and the cyclic steady state condition. Large-scale optimization capabilities have enabled us to adopt a complete discretization methodology to solve the optimal control problem as a large-scale nonlinear program, using the nonlinear optimization solver IPOPT. The superstructure approach is demonstrated for case studies related to post-combustion CO2 capture. In particular, optimal PSA cycles were synthesized, which maximize CO2 recovery for a given purity, and minimize overall power consumption. The results show the potential of the superstructure to predict PSA cycles with up to 98% purity and recovery of CO2. Moreover, for recovery of around 85% and purity of over 90%, these cycles can recover CO2 from atmospheric flue gas with a low power consumption of 465 k Wh tonne,1 CO2. The approach presented is, therefore, very promising and quite useful for evaluating the suitability of different adsorbents, feedstocks, and operating strategies for PSA, and assessing its usefulness for CO2 capture. Published 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Highly Potent and Selective Substrate Analogue Factor Xa Inhibitors Containing D -Homophenylalanine Analogues as P3 Residue: Part 2CHEMMEDCHEM, Issue 7 2007Anne Stürzebecher Dr. Abstract A series of highly potent substrate-analogue factor Xa inhibitors containing D -homophenylalanine analogues as the P3 residue has been identified by systematic optimization of a previously described inhibitor structure. An initial lead, benzylsulfonyl- d- hPhe-Gly-4-amidinobenzylamide (3), inhibits fXa with an inhibition constant of 6.0,nM. Most modifications of the P2 amino acid and P4 benzylsulfonyl group did not improve the affinity and selectivity of the compounds as fXa inhibitors. In contrast, further variation at the P3 position led to inhibitors with significantly enhanced potency and selectivity. Inhibitor 27, benzylsulfonyl- D -homo-2-pyridylalanyl(N-oxide)-Gly-4-amidinobenzylamide, inhibits fXa with a Ki value of 0.32,nM. The inhibitor has strong anticoagulant activity in plasma and doubles the activated partial thromboplastin time and prothrombin time at concentrations of 280,nM and 170,nM, respectively. Compound 27 inhibits the prothrombinase complex with an IC50 value of 5,nM and is approximately 50 times more potent than the reference inhibitor DX-9065a in this assay. [source] | ||||||||||