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AbstractTyrosol is a principle phenolic compound present in olive oil and wine with great pharmacological potentials due to its strong antioxidant property. Its application can be highly extended by increasing its lipophilicity through esterification. In this study, tyrosol esters were synthesized by enzymatic transesterification of tyrosol with vinyl esters, with a commercial lipase from Novozymes (Novozym 435, Candida antarctica lipase B (CALB) immobilized on macroporous acrylic resin beads) as the catalyst, both in organic solvents and in ionic liquids. Methyl tert-butyl ether (MTBE) was the best solvent, offering complete conversions towards the synthesis of tyrosol esters with varying chain lengths (C2-C18) within 1 h. Taking the enzymatic transesterification between tyrosol and vinyl acetate as the model reaction, 18 organic solvents and 24 ionic liquids were screened, and their solvent properties (i.e. hydrophobicity, polarity, viscosity, water activity, and partition coefficients of substrate and product) were correlated to the enzyme activity. Upon enzyme screening, four new lipases were found to be highly efficient, relative to the best-performed Novozym 435 and Lipozyme TLIM (Thermomyces lanuginosus lipase (TLL) immobilized on silica gel), in tyrosol ester synthesis. This work provides enzymatic methods of esterifying tyrosol that are much more efficient than those reported in literature, and will shed light on re-consideration of the roles of solvents in nonaqueous enzymology. [ABSTRACT FROM AUTHOR]

Follow-up experimental designs are frequently employed in a wide range of scientific studies and industries. Lower bounds of average mixture discrepancy for row augmented designs are determined in this paper utilizing the level permutation technique, which is also used to analyse the uniformity of row augmented designs with asymmetrical factorials. Between the row augmented designs and its initial designs or follow-up designs, quantitative relationships of lower bounds of average mixture discrepancy are constructed. Additionally, a proposal is made for the construction algorithm of asymmetrical uniform row augmented designs. Numerical examples indicate that the asymmetrical uniform row augmented designs can be constructed with high efficiency and recommended for use in practice. [ABSTRACT FROM AUTHOR]

Innovative design of complex systems faces multi-contradiction (MC). The existing methods to solve MC are mainly based on the General Theory of Powerful Thinking (OTSM) which is independent of the classical Engineering Design Method (ED) to form the process model, they cannot inherit the accumulated knowledge and advantages of ED. This paper proposes a product innovation design process model for MC based on the function-structure model. It starts with an initial scenario of the system to build the function-structure model and MC network based on the root contradiction analysis. The network structure entropy and function importance decision methods are introduced for the trimming target confirming. The key contradiction-node is identified and solved by strategies of trimming based on internal and external resources of the system. The function-structure model in ED and trimming in TRIZ are combined to form an innovative design process for MC systems. The proposed method is evaluated in a case study of an innovative design of the girder bridge erector. [ABSTRACT FROM AUTHOR]

Identifying, tracking and warning of the vortexed induced vibration (VIV) are essential for long-span suspension bridges because VIV might cause the driving safety problem. This study proposes an automatic method to identify and track the start and evolution of the VIV. Two feature indices, i.e. the energy concentration coefficient (ECC) and similarity ratio of amplitude (SRA), are utilised to form a feature index vector to identify and track the VIV. The Hilbert transform is utilised to process the vibration signal, based on which the SRA can be extracted. The k-means clustering method is introduced to automatically identify and track the VIV through automatically separating the feature index vectors into several clusters, and multi-level warming is established based on the acceleration root mean square (ARMS) value. The proposed method is validated using the in-field monitoring data of a suspension bridge suffering the VIV. The results indicate that the proposed automatic method can successfully distinguish the VIV from ambient vibration and can identify the forming of the VIV and track the evolution without any manual intervention, even for the VIV with low vibration amplitude. The multi-level warning can also be achieved based on the ARMS value when the VIV is identified. [ABSTRACT FROM AUTHOR]