A New Method for Elimination of Zero-Sequence Voltage in Dual Three-Level Inverter Fed Open-End Winding Induction Motors

Geng, Yi-Wen,Wei, Chen-Xi,Chen, Rui-Cheng,Wang, Liang,Xu, Jia-Bin,Hao, Shuang-Cheng The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

Due to the excessive zero-sequence voltage in dual three-level inverter fed open-end winding induction motor systems, zero-sequence circumfluence which is harmful to switching devices and insulation is then formed when operating in a single DC voltage source supplying mode. Traditionally, it is the mean value instead of instantaneous value of the zero-sequence voltage that is eliminated, through adjusting the durations of the operating vectors. A new strategy is proposed for zero-sequence voltage elimination, which utilizes unified voltage modulation and a decoupled SVPWM strategy to achieve two same-sized equivalent vectors for an angle of $120^{\circ}$, generated by two inverters independently. Both simulation and experimental results have verified its efficiency in the instantaneous value elimination of zero-sequence voltage.

A New Method for Elimination of Zero-Sequence Voltage in Dual Three-Level Inverter Fed Open-End Winding Induction Motors

Yi-Wen Geng,Chen-Xi Wei,Rui-Cheng Chen,Liang Wang,Jia-Bin Xu,Shuang-Cheng Hao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

Due to the excessive zero-sequence voltage in dual three-level inverter fed open-end winding induction motor systems, zero-sequence circumfluence which is harmful to switching devices and insulation is then formed when operating in a single DC voltage source supplying mode. Traditionally, it is the mean value instead of instantaneous value of the zero-sequence voltage that is eliminated, through adjusting the durations of the operating vectors. A new strategy is proposed for zero-sequence voltage elimination, which utilizes unified voltage modulation and a decoupled SVPWM strategy to achieve two same-sized equivalent vectors for an angle of 120°, generated by two inverters independently. Both simulation and experimental results have verified its efficiency in the instantaneous value elimination of zero-sequence voltage.

Effects of different culture systems on the culture of buffalo (Bubalus bubalis) spermatogonia stem cell-like cells in vitro

Ting-Ting Li,Shuang-Shuang Geng,Hui-Yan Xu,Ao-Lin Luo,Peng-Wei Zhao,Huan Yang,Xing-Wei Liang,Yang-Qing Lu,Xiao-Gan Yang,Ke-Huan Lu 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.1

Currently, the systems for culturing buffalo spermatogonial stem cells (SSCs) in vitro are varied, and their effects are still inconclusive. In this study, we compared the effects of culture systems with undefined (foetal bovine serum) and defined (KnockOut Serum Replacement) materials on the in vitro culture of buffalo SSC-like cells. Significantly more DDX4- and UCHL1-positive cells (cultured for 2 days at passage 2) were observed in the defined materials culture system than in the undefined materials system (p < 0.01), and these cells were maintained for a longer period than those in the culture system with undefined materials (10 days vs. 6 days). Furthermore, NANOS2 (p < 0.05), DDX4 (p < 0.01) and UCHL1 (p < 0.05) were expressed at significantly higher levels in the culture system with defined materials than in that with undefined materials. Induction with retinoic acid was used to verify that the cultured cells maintained SSC characteristics, revealing an SCP3+ subset in the cells cultured in the defined materials system. The expression levels of Stra8 (p < 0.05) and Rec8 (p < 0.01) were significantly increased, and the expression levels of ZBTB16 (p < 0.01) and DDX4 (p < 0.05) were significantly decreased. These findings provided a clearer research platform for exploring the mechanism of buffalo SSCs in vitro.

Expression and Clinical Significance of Myeloid Derived Suppressor Cells in Chronic Hepatitis B Patients

Lu, Li-Rong,Liu, Jing,Xu, Zhen,Zhang, Geng-Lin,Li, De-Chang,Lin, Chao-Shuang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.10

We here document discovery of expression profile of myeloid derived suppressor cells (MDSCs) in chronic hepatitis B (CHB) patients and changes in the course of disease. The study population was composed of 75 outpatient HBV cases and 15 healthy control cases. Peripheral blood samples were collected for separation of mononuclear cells. Levels of MDSCs labeled with Lin-DR-CD11b+CD33+ obtained from peripheral blood mononuclear cells (PBMC), were revealed to have significant differences between the CHB and other groups. They were 0.414% for health control cases and 0.226% for CHB cases (Z=-2.356, p=0.0189). It also observed that the group of HBeAg positive cases had significant difference in MDSCs/PBMC median ($X^2=11.877$, p=0.003), compared with group of HBeAg negative cases and the healthy control group. It suggested considerable MDSCs might be involved in HBeAg immune tolerance. In addition, negative correlations between MDSCs/PBMC and parameters of ALT, AST and TBil, while positive correlation between MDSCs/PBMC and ALB parameter were found. Multiple comparisons between the four phases and health control phase again, there was a statistically sifnificant difference ($X^2=17.198$, p=0.002). Taken together, these findings may provide a new immunotherapy strategy for reduced the expression levels of MDSCs in CHB patients, through induction of an autoimmune response to virus removal.

Analysis of heat transfer performance of ORC direct contact heat exchanger by GRA-VMD-LSSVM model using optimization

Guanfeng Zheng,Qingtai Xiao,Shusheng Zhu,Hua Wang,Jian Geng,Shuang Zhao,Junwei Huang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7

The relationship between heat transfer effect and influencing factors in direct contact with evaporator isstudied. It is important to optimize the design and setting of direct contact heat exchangers and further improve theheat transfer process of heat exchangers by understanding the influencing factors of direct contact evaporator. Themethods used are grey correlation analysis, variational mode decomposition and least square support vector machinealgorithm to calculate the experimental heat transfer coefficient. The conclusions are that grey relation analysis can findthe complex relationship between different influencing factors and reduce the amount of data to improve the accuracyof prediction. Hence, the novelty of this paper is to propose a simple, efficient and accurate hybrid prediction model forVHTC prediction. The place where it goes beyond previous efforts in the literature is that different influencing factorson the heat transfer performance in the direct contact heat transfer process are considered. The results show that theprediction accuracy of the heat transfer coefficient can be improved by 7% by optimizing the data only with grey correlationanalysis. The prediction accuracy can be improved up to 53% after using the hybrid model.

Expression and regulation of Angiopoietins and their receptor Tie-2 in sika deer antler

Hong-Liang Zhang,Bin Guo,Zhan-Peng Yue,Lu Zhang,Zhan-Qing Yang,Shuang Geng,Kai Wang,Hai-Fan Yu 한국통합생물학회 2017 Animal cells and systems Vol.21 No.3

The cartilage vascularization and chondrocyte survival are essential for endochondral ossification which occurs in the process of antler growth. Angiopoietins (Ang) is a family of major angiogenic growth factors and involved in regulating the vascularization. However, the expression and regulation of Angs in the antler are still unknown. The aim of this study is to localize the expression of Ang-1, Ang-2 and their receptor Tie-2 in sika deer antler using in situ hybridization and focused on analyzing the regulation of testosterone, estrogen, all-trans-retinoic acid (ATRA) and 9cRA on their expression in antler chondrocytes. The results showed that Ang-1, Ang-2 and Tie-2 were highly expressed in antler chondrocytes. Administration of testosterone to antler chondrocytes led to a notable increase in the expression of Ang-1 and Tie-2, and a reduction in the expression of Ang-2. The similar result was also observed after estrogen treatment. In contrast, ATRA and 9cRA could inhibit the expression of Ang-1 in antler chondrocytes and heighten the expression of Ang-2. Simultaneously, ATRA could downregulate the expression of Tie-2 in antler chondrocytes at 12 and 24 h, while 9cRA upregulate the expression of Tie-2 at 3 and 6 h. Collectively, Ang-1, Ang-2 and Tie-2 are expressed in antler chondrocytes and their expression can be affected by testosterone, estrogen, ATRA and 9cRA.