Adaptive Controller Design for a Synchronous Generator with Unknown Perturbation in Mechanical Power

Xiaohong Jiao,Yuanzhang Sun,Tielong Shen 대한전기학회 2005 International Journal of Control, Automation, and Vol.3 No.2

Transient stabilization with voltage regulation is investigated for a synchronous generator when the mechanical power is perturbed to any unknown value within its physical bounds so that the operating point of the system shifts to an unknown point. An adaptive excitation controller is designed based on the backstepping method with tuning functions. It will be shown that the adaptive control law proposed can achieve the convergence of the system states to the new equilibrium point in correspondence with the real value of the unknown mechanical power and the regulation of the terminal voltage to the required value. Simulation results are given to demonstrate the effectiveness of the proposed controller for the transient stabilization and voltage regulation.

Carvacrol improves blood lipid and glucose in rats with type 2 diabetes mellitus by regulating short-chain fatty acids and the GPR41/43 pathway

Sun Yan,Qu Hai,Niu Xiaohong,Li Ting,Wang Lijuan,Peng Hairui 대한약리학회 2024 The Korean Journal of Physiology & Pharmacology Vol.28 No.1

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia and dyslipidemia. Carvacrol (CAR) has demonstrated the potential to mitigate dyslipidemia. This study aims to investigate whether CAR can modulate blood glucose and lipid levels in a T2DM rat model by regulating short-chain fatty acids (SCFAs) and the GPR41/43 pathway. The T2DM rat model was induced by a high-fat diet combined with low-dose streptozocin injection and treated with oral CAR and/or mixed antibiotics. Fasting blood glucose, oral glucose tolerance, and insulin tolerance tests were assessed. Serum lipid parameters, hepatic and renal function indicators, tissue morphology, and SCFAs were measured. In vitro, high glucose (HG)-induced IEC-6 cells were treated with CAR, and optimal CAR concentration was determined. HG-induced IEC-6 cells were treated with SCFAs or/and GPR41/43 agonists. CAR significantly reduced blood lipid and glucose levels, improved tissue damage, and increased SCFA levels in feces and GPR41/43 expression in colonic tissues of T2DM rats. CAR also at tenuated HG-induced apoptosis of IEC-6 cells and enhanced GPR41/43 expression. Overall, these findings suggest that CAR alleviates blood lipid and glucose abnormalities in T2DM rats by modulating SCFAs and the GPR41/43 pathway.

Adaptive Controller Design for a Synchronous Generator with Unknown Perturbation in Mechanical Power

Jiao Xiaohong,Sun Yuanzhang,Shen Tielong Institute of Control 2005 International Journal of Control, Automation, and Vol.3 No.S

Transient stabilization with voltage regulation is investigated for a synchronous generator when the mechanical power is perturbed to any unknown value within its physical bounds so that the operating point of the system shifts to an unknown point. An adaptive excitation controller is designed based on the backstepping method with tuning functions. It will be shown that the adaptive control law proposed can achieve the convergence of the system states to the new equilibrium point in correspondence with the real value of the unknown mechanical power and the regulation of the terminal voltage to the required value. Simulation results are given to demonstrate the effectiveness of the proposed controller for the transient stabilization and voltage regulation.

Research on flexible job-shop scheduling problem based on a modified genetic algorithm

Wei Sun,Ying Pan,Xiaohong Lu,Qinyi Ma 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.10

Aiming at the existing problems with GA (genetic algorithm) for solving a flexible job-shop scheduling problem (FJSP), such as description model disunity, complicated coding and decoding methods, a FJSP solution method based on GA is proposed in this paper, and job-shop scheduling problem (JSP) with partial flexibility and JIT (just-in-time) request is transformed into a general FJSP. Moreover, a unified mathematical model is given. Through the improvement of coding rules, decoding algorithm, crossover and mutation operators,the modified GA’s convergence and search efficiency have been enhanced. The example analysis proves the proposed methods can make FJSP converge to the optimal solution steadily, exactly, and efficiently.

Robust Decentralized Fault Estimation for Loss of Actuator Effectiveness of Multi-motor Web-winding System

Xiaoyan Chu,Xiaohong Nian,Miaoping Sun,Haibo Wang,Hongyun Xiong 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.3

This paper develops a method estimating the actuator power loss faults for the multi-motor web-windingsystem. Firstly, the web-winding system is regarded as a synthetic system with several dynamic subsystems andtheir dynamic models are given. Then, the nonlinear coordinate transformation is introduced to obtain a transformedsystem with block triangular structure and the interconnections among subsystems are allowed. Next, a decentralizedadaptive high-gain observer with sliding-mode is designed for the obtained transformed system to estimate thesystem actuator power loss faults. Meanwhile, the estimation error dynamics can be obtained. Sufficient conditionsof asymptotic stability for estimation error system are derived by Lyapunov theory, and the sliding-mode gain andfault estimation law are achieved. After that, the fault estimation observer for original multi-motor web-windingsystem is designed by inverse coordinate transformation. Finally, the simulations and analysis are implemented onthe three-motor web-winding system to verify the effectiveness of the proposed method.

Construction of Glycerol Synthesis Pathway in Klebsiella pneumoniae for Bioconversion of Glucose into 1,3-Propanediol

Hong Zong,Xiaohong Liu,Wenqiang Chen,Bin Zhuge,Jin Sun 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.5

1,3-Propanediol (1,3-PDO) is an important three-carbon compound widely used in new polyester polymer materials. Natural organisms that can produce 1,3- PDO from glycerol were well studied. However, no natural microorganisms found could directly convert glucose to 1,3-PDO due to its insufficient glycerol synthesis pathway. In this study, two essential glycerol synthesis genes, CgGPD gene (encoding glycerol-3-phosphate dehydrogenase from Candida glycerinogenes) and ScGPP2 gene (encoding glycerol-3-phosphatase from Saccharomyces cerevisiae), were expressed in wild-type Klebsiella pneumoniae, a natural 1,3-PDO producers with reduction pathway for 1,3- PDO synthesis from glycerol. The results of fermentation, key enzyme activities, and metabolites analysis confirmed that recombinant K. pneumoniae now possessed a metabolic pathway capable of converting glucose to 1,3-PDO. The strain could produce 1,3-PDO from glucose with a final titer of 17.27 g/L with 40 g/L glucose in the medium, showing a 1.26-fold increase compared with 30 g/L glucose. Also, adding certain concentrations of glycerol could quickly initiate the 1,3-PDO synthetic pathway and promote the accumulation of 1,3-PDO, which could shorten the fermentation cycle. These results have important implications for further studies involving the use of one strain for bioconversion of glucose to 1,3-PDO.

The Discusion and Optimization Research on HSD17B13 Protein Separation and Purification Technology

Yan Cheng,Zhen Wan,Xiaohong Sun ASCONS 2022 IJASC Vol.4 No.3

Background/Objectives: The Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects nearly a quarter of the world population. Recent studies have shown that there is a close relationship between liver lipid-titrated 17β Hydroxysteroid Dehydrogenase Type 13(HSD17B13)protein and NAFLD. At the same time, the purification of HSD has been trying to find better conditions and methods, at present, the HSD protein separation and purification technology is incomplete, the cost is high, the purity is low, the purification quantity is small and so on. This paper first reviewed the research progress of Steatosis and some basic properties about HSD, such as HSD expression site, Lipid titration function, in vitro catalytic substrates, and the relationship between HSD and liver diseases.. Methods/Statistical analysis: The optimization of HSD purification method is considered be of great help to the further study of its structure and function, so this research put forward two hypotheses to explore its effect on the purification of HSD. The first is to change the kind of tag when expressing plasmid in E. coli, so as to change the adsorption degree of protein with corresponding group and beads, and the second is to change the concentration of different components in Wash Buffer, the aim is to find the best concentration for removing foreign protein and maintaining the adsorption capacity of HSD. Findings: The purity of HSD is closely related to tag species and Wash Buffer concentration in different experimental groups, his-Binding Buffer with 0.5% sodium deoxycholate powder added and Wash Buffer with Tris-HCl 50 mM, NACL 300 mM, Imidazole 40 mM for each component are used. Improvements/Applications: After the better purification effect, the higher purity HSD can pave the way for the future study of its potential substrate and mechanism of action.

Sevoflurane induces neuronal apoptosis via enhancing DNMT3L expression and promoting methylation of PSD95 promoter in postoperative cognitive dysfunction

Ling Yunzhi,Li Xiaohong,Yu Li,Sun Yiyun,Yang Dongdong,Li Zhiyi 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.3

Background Postoperative cognitive dysfunction (POCD) is a central nervous system (CNS) complication and occurs quite frequently after anesthesia, especially in elderly patients. DNA (cytosine-5)-methyltransferase 3-like (DNMT3L) is an enzymatically inactive regulatory factor that can modulate gene expression via methylation. Few studies specifically focused on the role of DNMT3L in sevoflurane-induced POCD. Objective The cognitive dysfunction was determined by Morris water maze assay. Hippocampal neuron apoptosis was measured by TdT-mediated dUTP nick-end labeling (TUNEL) assay. Neuron proliferation and apoptosis were measured by cell counting kit-8 (CCK-8) and flow cytometry assay. The expression levels of DNMT3L and postsynaptic density protein-95 (PSD95) were measured by qRT-PCR and western blot. Results The sevoflurane-induced POCD aging rat model was established for in vivo study. Suppression of DNA methylation by 5-Aza-2′-deoxycytidine (5-AZA; a widely used methylation inhibitor) reversed sevoflurane-induced cognitive dysfunction and hippocampal neuron apoptosis in rats. Moreover, sevoflurane enhanced DNMT3L expression and induced methylation of PSD95 promoter in vivo. In vitro, sevoflurane induced neuronal apoptosis and DNMT3L expression to promote PSD95 methylation. Finally, rescue experiments indicated that sevoflurane induced neuron apoptosis by increasing DNMT3L expression and promoting methylation of PDS95 in POCD. Conclusion Sevoflurane induced neuronal apoptosis by increasing DNMT3L expression and promoting methylation of PDS95 in vivo and in vitro, providing a novel therapeutic strategy for POCD.

Weak magnetic field accelerates chromate removal by zero-valent iron

Feng, Pian,Guan, Xiaohong,Sun, Yuankui,Choi, Wonyong,Qin, Hejie,Wang, Jianmin,Qiao, Junlian,Li, Lina Elsevier 2015 Journal of environmental sciences Vol.31 No.-

<P>Weak magnetic field (WMF) was employed to improve the removal of Cr(VI) by zero-valent iron (ZVI) for the first time. The removal rate of Cr(VI) was elevated by a factor of 1.12-5.89 due to the application of a WMF, and the WMF-induced improvement was more remarkable at higher Cr(VI) concentration and higher pH. Fe2+ was not detected until Cr(VI) was exhausted, and there was a positive correlation between the WMF-induced promotion factor of Cr(VI) removal rate and that of Fe2+ release rate in the absence of Cr(VI) at pH4.0-5.5. These phenomena imply that ZVI corrosion with Fe2+ release was the limiting step in the process of Cr(VI) removal. The superimposed WMF had negligible influence on the apparent activation energy of Cr(VI) removal by ZVI, indicating that WMF accelerated Cr(VI) removal by ZVI but did not change the mechanism. The passive layer formed with WMF was much more porous than without WMF, thereby facilitating mass transport. Therefore, WMF could accelerate ZVI corrosion and alleviate the detrimental effects of the passive layer, resulting in more rapid removal of Cr(VI) by ZVI. Exploiting the magnetic memory of ZVI, a two-stage process consisting of a small reactor with WMF for ZVI magnetization and a large reactor for removing contaminants by magnetized ZVI can be employed as a new method of ZVI-mediated remediation.</P>

Optimal Sizing and Energy Management of Hybrid Energy Storage System for High-Speed Railway Traction Substation

Tang Sida,Huang Xiaohong,Li Qunzhan,Yang Naiqi,Liao Qinyu,Sun Ke 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Traction power fl uctuations have economic and environmental eff ects on high-speed railway system (HSRS). The combination of energy storage system (ESS) and HSRS shows a promising potential for utilization of regenerative braking energy and peak shaving and valley fi lling. This paper studies a hybrid energy storage system (HESS) for traction substation (TS) which integrates super-capacitor (SC) and vanadium redox battery (VRB). According to the characteristics of the traction load under actual operating conditions, an energy management strategy with fi xed-period control (FPC) is proposed, which fully leverages the periodicity and regularity of HSRS operation. To achieve the optimal size, economic feasibility is selected as the optimization objective, which is fully assessed in terms of Net Present Value (NPV). The optimization constraints are formulated in which the Discrete Fourier Transform (DFT) is performed for power allocation between SC and VRB. Besides, an improved mutation-based particle swarm optimization (IMBPSO) is proposed to effi ciently solve the optimization and enhance convergence performance. Finally, combined with the measured traction load data, the eff ectiveness of the FPC energy management strategy is verifi ed and the optimal scale of the HESS is provided.