A High Torque and Low Ripple Magnetic Gear with Embedded Permanent Magnet

Tan Can,Jing Libing,Liu Wei,Rao Yingying,Tang Weizhao 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

In order to further improve the output torque and transmission stability of coaxial magnetic gear (CMG), a new topology of embedded permanent magnets (PMs) is proposed in this paper, which has large torque and low ripple. In the structure, the PMs of the inner rotor are embedded into the yoke and radial magnetization is adopted. On the outer rotor, the PMs are magnetized by the Halbach array. At the same time, in this magnetization mode, the PMs with radial magnetization are moved a certain distance towards the outer rotor yoke. At this time, the gap between the PMs and the outer air gap is filled with silicon steel, so that part of the PMs is embedded in the yoke, and the parallel magnetization PMs is still in the original position. Finally, a two-dimensional model is established, and the magnetic field and torque of the model are optimized. Compared with the conventional CMG model, it is found that the improved model increases the average output torque of the inner and outer rotors by 16.08% and 16.87%, respectively, and reduces the ripple by 18.85% and 43.26%, respectively. It is proved that the topology is an effective attempt to improve the operation efficiency of CMG.

Calculation of Torque and Loss of Coaxial Magnetic Gear with Halbach Array in 3D Model

Jing Libing,Liu Wei,Tang Weizhao,Rao Yingying,Tan Can,Ben Tong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

In two-dimensional fi eld, the end eff ect exists in the calculation of the electromagnetic characteristics of the magnetic gear, which leads to the inaccurate calculation of the air-gap magnetic fi eld and torque. In order to improve the calculation accuracy of the electromagnetic characteristics of the magnetic gear, a 3D coaxial magnetic gear (CMG) with Halbach arrays distribution is proposed in this paper. Using the unilateral eff ect of the Halbach arrays, the magnetic fi eld on the air gap side is strengthened, and the magnetic fi eld on the iron yoke side is weakened. The topology of CMG with 4 inner and 17 outer poles is established and compared with the 2D model with the same parameters. The results show that the 3D CMG with Halbach array distribution can eff ectively reduce the torque ripple, and the accuracy of torque and loss calculation is improved compared with 2D model. The analysis results can provide a basis for the design and manufacture of magnetic gear.

Characteristic Analysis of Magnetic Gear with Copper Bar

Sun Han,Wang Youzhong,Tan Can,Jing Libing 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

The coaxial magnetic gear (CMG) has the problem of the high content of non-working air gap harmonics during the process of rotation. In order to further reduce the component of useless harmonics and reduce the ripple of CMG. Based on the conventional magnetic gear model, in this paper, a magnetic gear model with copper bars is proposed, the inner yoke of the topology is octagonal, the permanent magnets (PMs) are pasted on the yoke surface, and radial magnetization is adopted, the copper bar is placed at the contact of the two magnetic poles; the outer PMs is magnetized by spoke magnetization, and part of the iron yoke is replaced by the copper bar. A CMG topology with 4 pole pairs inner rotor and 17 pole pairs outer rotor is established by fnite element method. Finally, the magnetic feld and torque of the topology are optimized, and the air gap fux density and torque ripple are analyzed. Compared with the conventional CMG, the improved model can not only reduce the torque ripple but also reduce the amount of PMs. It is proved that the topology is an efective attempt to improve the output stability of CMG.

Correction: Characteristic Analysis of Magnetic Gear with Copper Bar

Sun Han,Wang Youzhong,Tan Can,Jing Libing 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

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Improved DV-Hop Localization Algorithm Based on Distance Correction of Anchor Nodes

Lei Wu,Zhongwei Hou,Can Tan,Dengyuan Xu 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.10

This paper presents a kind of DV-Hop localization algorithm based on distance correction of nodes. This algorithm introduces the concept of distance correction factor and combines with the node communication radius to correct the average distance of each hop between unknown node and anchor node,and makes it be closer to the real value. The simulation results show that the proposed algorithm can reduce the average localization error of node, and when the value of distance correction factor is 0.8,the average localization error of node under DA-DV-Hop localization algorithm is reduced 15.53% than the traditional DV-Hop localization algorithm.

Are Systemic Voriconazole and Caspofungin Ototoxic? An Experimental Study with Rats

Emine Aydın,Filiz Aydoğan,,Eren Taştan,,Ayşe İriz,Gökhan Karaca,İlknur Haberal Can 대한이비인후과학회 2012 Clinical and Experimental Otorhinolaryngology Vol.5 No.3

Objectives. To determine whether systemic administration of voriconazole and caspofungin causes ototoxicity. Methods. This study was conducted on 32 healthy male Wistar albino rats. The baseline auditory brainstem response (ABR)thresholds of all animals were obtained under general anesthesia. Then, the rats were randomly divided into 4 groups (groups I-IV), each group consisting of 8 rats. Rats in group I were injected intraperitoneally with voriconazole 10 mg/kg/day for 7 days, and the rats in the group II were injected intraperitoneally with caspofungin 5 mg/kg/day for 7 days. Group III received 120 mg/kg/day gentamicin for 7 days. Group IV received saline for 7 days. The animals were then observed for 7 days, and on 14th day of the trial, posttreatment ABRs of both ears were recorded. Results. We did not find any significant differences between pretreatment and posttreatment median ABR thresholds in the voriconazole, caspofungin, or saline groups. In the gentamicin group, there was a statistically significant difference between pretreatment and posttreatment ABR thresholds. Conclusion. Caspofungin and voriconazole did not change ABR thresholds in speech frequencies after a 7-day-period of their administration. We believe that further animal studies must be performed after administration of these agents for a longer time period, and these findings must be consolidated with histopathological investigations. Objectives. To determine whether systemic administration of voriconazole and caspofungin causes ototoxicity. Methods. This study was conducted on 32 healthy male Wistar albino rats. The baseline auditory brainstem response (ABR)thresholds of all animals were obtained under general anesthesia. Then, the rats were randomly divided into 4 groups (groups I-IV), each group consisting of 8 rats. Rats in group I were injected intraperitoneally with voriconazole 10 mg/kg/day for 7 days, and the rats in the group II were injected intraperitoneally with caspofungin 5 mg/kg/day for 7 days. Group III received 120 mg/kg/day gentamicin for 7 days. Group IV received saline for 7 days. The animals were then observed for 7 days, and on 14th day of the trial, posttreatment ABRs of both ears were recorded. Results. We did not find any significant differences between pretreatment and posttreatment median ABR thresholds in the voriconazole, caspofungin, or saline groups. In the gentamicin group, there was a statistically significant difference between pretreatment and posttreatment ABR thresholds. Conclusion. Caspofungin and voriconazole did not change ABR thresholds in speech frequencies after a 7-day-period of their administration. We believe that further animal studies must be performed after administration of these agents for a longer time period, and these findings must be consolidated with histopathological investigations.

Causal Relations between Exposome and Stroke: A Mendelian Randomization Study

Hong-Qi Li,Yi-Wei Feng,Yu-Xiang Yang,Xin-Yi Leng,Prof Can Zhang,Shi-Dong Chen,Kevin Kuo,Shu-Yi Huang,Xue-Qing Zhang,Yi Dong,Xiang Han,Xin Cheng,Mei Cui,Lan Tan,Qiang Dong,Jin-Tai Yu 대한뇌졸중학회 2022 Journal of stroke Vol.24 No.2

Background and Purpose To explore the causal relationships of elements of the exposome with ischemic stroke and its subtypes at the omics level and to provide evidence for stroke prevention. Methods We conducted a Mendelian randomization study between exposure and any ischemic stroke (AIS) and its subtypes (large-artery atherosclerotic disease [LAD], cardioembolic stroke [CE], and small vessel disease [SVD]). The exposure dataset was the UK Biobank involving 361,194 subjects, and the outcome dataset was the MEGASTROKE consortium including 52,000 participants. Results We found that higher blood pressure (BP) (systolic BP: odds ratio [OR], 1.02; 95% confidence interval [CI], 1.01 to 1.04; diastolic BP: OR, 1.03; 95% CI, 1.01 to 1.05; pulse pressure: OR, 1.03; 95% CI, 1.00 to 1.06), atrial fibrillation (OR, 1.18; 95% CI, 1.13 to 1.25), and diabetes (OR, 1.13; 95% CI, 1.07 to 1.18) were significantly associated with ischemic stroke. Importantly, higher education (OR, 0.69; 95% CI, 0.60 to 0.79) decreased the risk of ischemic stroke. Higher systolic BP (OR, 1.06; 95% CI, 1.02 to 1.10), pulse pressure (OR, 1.08; 95% CI, 1.02 to 1.14), diabetes (OR, 1.28; 95% CI, 1.13 to 1.45), and coronary artery disease (OR, 1.58; 95% CI, 1.25 to 2.00) could cause LAD. Atrial fibrillation could cause CE (OR, 1.90; 95% CI, 1.71 to 2.11). For SVD, higher systolic BP (OR, 1.04; 95% CI, 1.00 to 1.07), diastolic BP (OR, 1.06; 95% CI, 1.01 to 1.12), and diabetes (OR, 1.22; 95% CI, 1.10 to 1.36) were causal factors. Conclusions The study revealed elements of the exposome causally linked to ischemic stroke and its subtypes, including conventional causal risk factors and novel protective factors such as higher education.

Relation between Ki-67, ER, PR, Her2/neu, p21, EGFR, and TOP II-α Expression in Invasive Ductal Breast Cancer Patients and Correlations with Prognosis

Yan, Jian,Liu, Xiao-Long,Han, Lu-Zhe,Xiao, Gang,Li, Ning-Lei,Deng, Yi-Nan,Yin, Liang-Chun,Ling, Li-Juan,Yu, Xiao-Yuan,Tan, Can-Liang,Huang, Xiao-Ping,Liu, Li-Xin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

The aim of the present study was to investigate the expression of the transcription factor Ki-67, ER, PR, Her2/neu, p21, EGFR, and TOP II-${\alpha}$ in the tumor tissue of patients with invasive ductal carcinoma(IDC); in addition, we examined correlations between these markers. Two hundred and sixteen IDC patients, who were not previously been treated with chemo- or radiotherapy, were included in the study. All tumors were grade I-III. Expression of molecular markers was determined by immunohistochemical analysis on paraffin-embedded tissue sections. Follow-up data were collected for 3 months to 10 years and analyzed for tumor recurrence, survival time, and prognostic risk factors. We determined Ki-67 expression correlates with the expression of ER, PR, HER-2, EGFR, and TOP-${\alpha}$, as well as lymph node involvement, high tumor grade, lymphovascular invasion, high tumor stage, and high TNM stage in IDC. Positive Ki-67 expression was a risk factor for rapid tumor recurrence and may help tumor progression, leading to poor prognosis in IDC. Ki-67 was directly correlated with EGFR, TOP II-${\alpha}$, lymph node involvement, high tumor grade, lymphovascular invasion, high tumor stage, and high TNM stage in the hormone receptor subtypes of breast cancer. In triple negative breast cancer, Ki-67 correlated with TOP II-${\alpha}$. Expression of Ki-67 correlated with that of ER, PR, HER-2, EGFR, TOP II-${\alpha}$, and p21. In addition, the biomarker Ki-67 has a role as a prognostic factor and indicates a poor prognosis in IDC.