Inductances Evaluation of a Squirrel-Cage Induction Motor with Curved Dynamic Eccentricity

Lv, Qiang,Bao, Xiaohua,He, Yigang,Fang, Yong,Cheng, Xiaowei The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

Eccentricity faults more or less exist in all rotating electrical machines. This paper establishes a more precise model of dynamic eccentricity (DE) in electrical machines named as curved dynamic eccentricity. It is a kind of axial unequal eccentricity which has not been investigated in detail so far but occurs in large electrical machines. The inductances of a large three-phase squirrel-cage induction machine (SCIM) under different levels of curved DE conditions are evaluated using winding function approach (WFA). These inductances include the stator self and mutual inductances, rotor self and mutual inductances, and mutual inductances between stator phases and rotor loops. A comparison is made between the calculation results under curved DE and the corresponding pure DE conditions. It indicates that the eccentricity condition will be more terrible than the monitored eccentricity based on the conventional pure DE model.

Inductances Evaluation of a Squirrel-Cage Induction Motor with Curved Dynamic Eccentricity

Qiang Lv,Xiaohua Bao,Yigang He,Yong Fang,Xiaowei Cheng 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

Eccentricity faults more or less exist in all rotating electrical machines. This paper establishes a more precise model of dynamic eccentricity (DE) in electrical machines named as curved dynamic eccentricity. It is a kind of axial unequal eccentricity which has not been investigated in detail so far but occurs in large electrical machines. The inductances of a large three-phase squirrel-cage induction machine (SCIM) under different levels of curved DE conditions are evaluated using winding function approach (WFA). These inductances include the stator self and mutual inductances, rotor self and mutual inductances, and mutual inductances between stator phases and rotor loops. A comparison is made between the calculation results under curved DE and the corresponding pure DE conditions. It indicates that the eccentricity condition will be more terrible than the monitored eccentricity based on the conventional pure DE model.

TRIM22 promotes the proliferation of glioblastoma cells by activating MAPK signaling and accelerating the degradation of Raf-1

Fei Xiaowei,Dou Ya-nan,Sun Kai,Wei Jialiang,Guo Qingdong,Wang Li,Wu Xiuquan,Lv Weihao,Jiang Xiaofan,Fei Zhou 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The tripartite motif (TRIM) 22 and mitogen-activated protein kinase (MAPK) signaling pathways play critical roles in the growth of glioblastoma (GBM). However, the molecular mechanism underlying the relationship between TRIM22 and MAPK signaling remains unclear. Here, we found that TRIM22 binds to exon 2 of the sphingosine kinase 2 (SPHK2) gene. An ERK1/2-driven luciferase reporter construct identified TRIM22 as a potential activator of MAPK signaling. Knockout and overexpression of TRIM22 regulate the inhibition and activation of MAPK signaling through the RING-finger domain. TRIM22 binds to Raf-1, a negative regulator of MAPK signaling, and accelerates its degradation by inducing K48-linked ubiquitination, which is related to the CC and SPRY domains of TRIM22 and the C1D domain of Raf-1. In vitro and in vivo, an SPHK2 inhibitor (K145), an ERK1/2 inhibitor (selumetinib), and the nonphosphorylated mutant Raf-1S338A inhibited GBM growth. In addition, deletion of the RING domain and the nuclear localization sequence of TRIM22 significantly inhibited TRIM22-induced proliferation of GBM cells in vivo and in vitro. In conclusion, our study showed that TRIM22 regulates SPHK2 transcription and activates MAPK signaling through posttranslational modification of two critical regulators of MAPK signaling in GBM cells.

Root hair‐specific expansins modulate root hair elongation in rice

ZhiMing, Yu,Bo, Kang,XiaoWei, He,ShaoLei, Lv,YouHuang, Bai,WoNa, Ding,Ming, Chen,Hyung‐,Taeg, Cho,Ping, Wu Blackwell Publishing Ltd 2011 The Plant journal Vol.66 No.5

<P><B>Summary</B></P><P>Root hair growth requires intensive cell‐wall modification. This study demonstrates that root hair‐specific expansin As, a sub‐clade of the cell wall‐loosening expansin proteins, are required for root hair elongation in rice (<I>Oryza sativa</I> L.). We identified a gene encoding <I>EXPA17</I> (<I>OsEXPA17</I>) from a rice mutant with short root hairs. Promoter::reporter transgenic lines exhibited exclusive <I>OsEXPA17</I> expression in root hair cells. The OsEXPA17 mutant protein (OsexpA17) contained a point mutation, causing a change in the amino acid sequence (Gly104→Arg). This amino acid alteration is predicted to disrupt a highly conserved disulfide bond in the mutant. Suppression of <I>OsEXPA17</I> by RNA interference further confirmed requirement for the gene in root hair elongation. Complementation of the <I>OsEXPA17</I> mutant with other root hair EXPAs (OsEXPA30 and Arabidopsis EXPA7) can restore root hair elongation, indicating functional conservation of these root hair EXPAs in monocots and dicots. These results demonstrate that members of the root hair EXPA sub‐clade play a crucial role in root hair cell elongation in Graminaceae.</P>

Optimization analysis of factors affecting hydrocarbon gas drive based on orthogonal experimental design

Wei Huang,Shenglai Yang,Zhilin Wang,Xiaowei Lv,Hao Lei,Li Chen 한국자원공학회 2014 Geosystem engineering Vol.17 No.6

To improve the ultimate recovery of reservoirs and to increase the economic benefit of oilfields, we feel obliged to study on various factors affecting the development effect of hydrocarbon gas injection and its influence in terms of ultimate recovery. Thus, we can formulate a reasonable and feasible scheme on effective implementation of hydrocarbon gas drive. Take Q28 fault-block as an example; five main factors affecting the development effect of hydrocarbon gas injection have been screened out, four different levels of each influence factor has been set up; the orthogonal experiment method has been adopted to design 16 different combination schemes of 5 factors. Numerical reservoir simulation predicted the final recovery under the different combination schemes. Following are the range analysis and variance analysis of entire results so that the major and minor factors affecting the final recovery and the best range of each factor can be confirmed. The order sequence from major to minor factors: gas injection slug size, gas injection time, gas–water ratio, pressure level, and injection rate. This method is significant on its guidance for hydrocarbon gas injection in this area.

An experimental study on low-velocity nonlinear flow in vuggy carbonate reservoirs

Haitao Wu,Fujun Li,Jiawen Liu,Jiang Chen,Xiaowei Lv,Wei Hu 한국자원공학회 2016 Geosystem engineering Vol.19 No.4

Vuggy carbonate reservoirs in the Middle East, which have characteristics such as high porosity, low permeability, and few fractures, are significantly different from fractured-vuggy carbonate reservoirs. In this study, single-phase flow experiments and core mercury injection experiments were conducted to analyze the pore size distribution and low-velocity nonlinear flow characteristics of vuggy carbonate rocks in Halfaya oilfield. The results show that the relationship between pseudo-threshold pressure gradient and permeability in matrix carbonate rocks is linear. However, vuggy type does not exhibit the same linear relationship. Compared with matrix type, vuggy carbonate rock has a nonlinear flow zone when the pressure gradient is comparatively low and the nonlinear flow characteristics are quite different from those of low-permeability sandstone reservoirs. Because of the multi-polarization of flow channel radius in vuggy carbonate rocks, fluid stepwise starts flowing as the pressure gradient increases. Vuggy carbonate rock has a pseudo-threshold pressure gradient during the low-velocity flow, but the actual threshold pressure gradient does not exist. The concept of whole channel flow pressure gradient is presented in this paper. The results contribute to improve the understanding of low-velocity flow characteristics of vuggy carbonate reservoirs.