1,721,220 research outputs found
Systems biological approach for the enhanced production of polyhydroxyalkanoates by Escherichia coli
No full textIdentification and characterization of new enoyl-CoA hydratase in Pseudomonas putida KT2442
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Development of biosynthetic pathways for the medium-chain-length chiral hydroxycarboxylic acids in recombinant Escherichia coli
No full textCharacterization of enoyl-CoA hydratase involved in polyhydroxyalkanoate synthesis in Eschrichia coli FadB mutant strain
No full textDevelopment of biosynthetic pathways for the medium-chain-length chiral hydroxycarboxylic acids in recombinant Escherichia coli
No full textInfluence of nano powder on rheological behavior of bimodal feedstock in powder injection molding
No full textRheological behavior of feedstock, which highly affects the condition of green body, is substantial issue in powder injection molding process. In this paper, the influence of nano powder contents in bimodal feedstock on solids loading and rheological behavior has been investigated. The bimodal powders were fabricated with 100?nm and 4?��m sized 316L stainless steel powders, and mixed with wax-based binder system. The critical solids loading for each powder was measured by torque rheometer. In order to analyze net effect of nano powder ratio, all feedstocks were formulated as solids loading of 42?vol.%. Feedstock homogeneity was evaluated by rotational rheometer. Capillary rheometer test was conducted to measure the viscosity of feedstock with different temperatures, shear rates and nano powder ratios. Rheological parameters, like flow index, flow activation energy and moldability index, were calculated based on the capillary rheometer test. The results indicated the critical solids loading and feedstock homogeneity decreased as nano power ratio increased in bimodal feedstock. Rheological parameters were also affected by nano powder ratio, and the optimal mixing ratio of nano powder for moldability index was investigated as 12?vol.%. ? 2017 Elsevier B.V.1110sciescopu
MASTER CURVE MODEL FOR CHARACTERIZATION OF DECOMPOSITION AND DENSIFICATION BEHAVIOR OF PbAlNbO3-PbZrTiO3 CERAMICS
No full textIn this study, decomposition and densification behavior of PbAlNbO3-PbZrTiO3 (PAN-PZT) ceramics were characterized for powder injection molding process. Thermal gravity analysis and in-situ dilatometer experiment were carried out to construct master curve. Based on master curve model approach, one-combined master debinding curve (MDC) and master sintering curve (MSC) were constructed for piezoelectric PAN-PZT ceramics. Derived curves matched well with the experimental data. Process optimization and material development will be conducted based on characterization of master curve parameters.11Ysciescopu
Design, fabrication and characterization of micro flow sensor inspired by biological hair cell
No full textDesign, fabrication and characterization of micro flow sensor were investigated based on the inspiration of biological hair cell in a nature. The micro scale artificial hair cell sensor was designed as considering two parts; first the high aspect ratio cilium structure which works as a hair cell of fish and second the mechanoreceptor structure where the drag force by flow are actually measured. Parameters of cilium structure were designed based on static modelling as follow: 300 mu m diameter and 2 mm height. The high aspect ratio cilium structure was precisely fabricated using a hot embossing process with the developed separated micro mold system prepared by LIGA (from the German Lithographi, Galvanoformung, Abformung) process. The mechanoreceptor was formulated with a force sensitive resistor with four symmetric electrodes to analyze the direction and the magnitude of target flow. Performance of assembled sensor was characterized using the prepared water channel. Flow velocity was sensed with the magnitude of signal and the direction of flow was distinguished by analyzing the signals from four mechanoreceptors.111sciescopu
Effect of Nano Powder Ratio in Bimodal Powder Mixture on Powder Injection Molding
No full textOne of the significant advantages of nanopowder is activated sintering and better surface finish of the final components. However, because of its drawbacks like higher cost and low formability, the mixture of nano and micro powder emerged as an effective solution. In this research, effects of nanopowder in nano/micro bimodal feed-stock were studied. Bimodal powder in feedstock was prepared with nano and micro sized powders. These powders were mixed with different nanopowder volume ratio from 0 to 50%. The effects of nanopowder vol.% on the critical solids loading was investigated with rheometer experiments. From debinding behavior, apparent debinding activation energy for each feedstock was determined. Sintering behavior of micro and bimodal feed-stocks were analyzed by dilatometer and compared with die compacted specimen. Nanopowder effect on sintered density and hardness of the samples were verified as well. (C) 2016 Elsevier B.V. All rights reserved.1186sciescopu
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