155 research outputs found
EXTRACTION OF POLYSACCHARIDES FROM LINGZHI BY ULTRASONIC-ASSISTED ENZYMATIC METHOD
The medicinal values of polysaccharides (PS) in Lingzhi have been shown to lie in many anti-cancer effects and good benefits for human health. Lingzhi, which is rich in healthy PS, has been used more and more commonly in Vietnam in recent years. In the present work, ultrasonic-assisted enzymatic extraction (UAEE) was used for extraction of PS from Lingzhi. The experiments were conducted according to a Box-Behnken design (BBD), with four independent variables: solvent temperature, ultrasonic power, pH, and ultrasonic irradiation time. The results showed that the best adequate extraction conditions were extraction time of 144 min, extraction temperature of 55°C, ultrasonic power of 240W, pH 7.9, and ultrasonic irradiation time of 144 min. Under these conditions, the predicted optimal yield was 3.716%. Whereas by following the optimized conditions, the experimental yield of PS was 3.65% ± 0.14, which was in good agreement with that of the prediction. Compared to the hot water extraction (HWE) method, ultrasonic-assisted extraction (UAE) method and enzyme-assisted extraction (EAE) method, the yield of PS obtained by UAEE was favorable. The PS yield obtained by HWE, and EAE were 1.96% and 3.10%, respectively. These results demonstrated that UAEE was an appropriate and effective extraction of polysaccharides from Lingzhi
FMI Compliant Approach to Investigate the Impact of Communication to Islanded Microgrid Secondary Control
In multi-master islanded microgrids, the inverter controllers need to share
the signals and to coordinate, in either centralized or distributed way, in
order to operate properly and to assure a good functionality of the grid. The
central controller is used in centralized strategy. In distributed control,
Multi-agent system (MAS) is considered to be a suitable solution for
coordination of such system. However the latency and disturbance of the network
may disturb the communication from central controller to local controllers or
among agents or and negatively influence the grid operation. As a consequence,
communication aspects need to be properly addressed during the control design
and assessment. In this paper, we propose a holistic approach with
co-simulation using Functional Mockup Interface (FMI) standard to validate the
microgrid control system taking into account the communication network. A
use-case of islanded microgrid frequency secondary control with MAS under
consensus algorithm is implemented to demonstrate the impact of communication
and to illustrate the proposed holistic approach.Comment: Proceedings of the IEEE PES ISGT Asia 2017 conferenc
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