Improved Centripetal Force Type-Magnetic Bearing with Superior Stiff ness and Anti-interference Characteristics for Flywheel Battery System

Wei-Yu Zhang,Pengfei Zhu,Ling Cheng,Huang-Qiu Zhu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.3

In this study, an improved centripetal force type-magnetic bearing (CFT-MB) for a fl ywheel battery system is proposed, which is easy to process and it has better performance with superior stiff ness and anti-interference characteristics than that of the pure spherical CFT-MB. First, the confi guration, magnetic circuits, working principle and mathematical model of the improved CFT-MB are analyzed in detail. The electromagnetic characteristics are then analyzed. In comparison with the analysis results of the pure spherical CFT-MB, the improved CFT-MB has less cost, less force–displacement and force–defl ection stiff ness, and higher force-current stiff ness, which verify its preferable design concept. Related comparative experiments based on the prototype are also conducted. The stiff ness tests results verify the accuracy of the previously presented electromagnetic characteristic analysis results. Performance tests results show that the proposed improved CFTMB is superior to that of the original CFT-MB in resisting to the disturbance or the gyroscopic eff ect, which verifi es the accuracy of the theoretical analysis.

An improved design of inserted tooth finishing hob for involute gears

Hu Yong,Xiang Mingjun,Qiu Xing,Song Pengfei,Song Jingan,Peng Fuhua 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.8

Gear hobs are widely used to machine involute gears. However, using Archimedes worm as a base worm of the gear hob, which iscommon used in industry, leads to the generating of theoretical error of the gears. Even though this error can be eliminated by using theaccurate involute base worm or be greatly reduced by complicated modification of the shape of cutting edges, the manufacturing cost isvery high. Reported in this paper is an improved design of inserted tooth finishing hob for involute gears on a conventional hobbing machineaiming to eliminate this error in an economical way. For that purpose, both descriptive-geometry-based method and mathematicalanalyzing are employed to illustrate the major parameters of the base worm and the formation and parameters of the inserted tooth finishinghob. In addition, an approximating formation of the flank for the convenience of grinding the inserted tooth finishing hob is proposedand the errors that this substitution arc surface is discussed. Ultimately, the other advantages of this inserted finishing hob are demonstrated.

A Novel Method to Improve the Dispersibility of Silicon Nitride Powders in Aqueous Media

Bingjie Xu,Mengxing Li,Qi Chen,Pengfei Liu,Baosong Xu,Ben Qiu,Liang Xu,Zhao Han 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.9

The present study describes a novel method to improve the dispersibility of silicon nitride powders in aqueous media. Specifically, a new Si3N4@g-C3N4 core–shell composite material was synthesized via annealing the mixture of silicon nitride and melamine under a nitrogen atmosphere using heating method. The effects of various initial mass ratios of Si3N4 and melamine on the structure and dispersibility of the composite were systematically investigated. The results of X-ray photoelectron spectroscopy and transmission electron microscope demonstrated that as-obtained Si3N4@g-C3N4 composite powders possess the core–shell structure, whereas the zeta potential and sedimentation analysis showed that they exhibit good dispersion in aqueous media. Furthermore, the colloidal dispersion of the composite powders is most stable when the initial mass ratio of Si3N4 and melamine is 100 : 3. The coated g-C3N4 could be completely removed in a cryogenic nitrogen atmosphere. The proposed process is expected to provide novel avenues for the study of dispersion of other inorganic powders.

Murine Model Study of a New Receptor-Targeted Tracer for Sentinel Lymph Node in Breast Cancer

Chonglin Tian,Xiao Sun,Bin-Bin Cong,Pengfei Qiu,Yongsheng Wang 한국유방암학회 2019 Journal of breast cancer Vol.22 No.2

Purpose: Sentinel lymph node biopsy (SLNB), a critical staging and treatment step, has replaced axillary lymph node (LN) dissection as the standard staging procedure for early stage breast cancer patients with clinically negative axillary LNs. Hence, using a murine sentinel lymph node (SLN) model, we investigated the localization effect of the new receptor-targeted tracer, indocyanine green (ICG)-rituximab, on breast cancer SLNB. Methods: After establishing the murine SLN model, different doses of ICG-rituximab were subcutaneously injected into the hind insteps of BALB/c mice to determine the optimal dose and imaging time using continuous (> 3 hours) MDM-I fluorescence vasculature imaging. To explore the capacity of ICG-rituximab for sustained SLN localization with the optimal dose, MDM-I imaging was monitored at 6, 12, and 24 hours. Results: The popliteal LN was defined as the SLN for hindlimb lymphatic drainage, the iliac LN as the secondary, and the para-aortic or renal LN as the tertiary LNs. The SLN initial imaging and optimal imaging times were shortened with increased ICG-rituximab doses, and the imaging rates of the secondary and tertiary LNs increased accordingly. The optimal ICG dose was 0.12 μg, and its optimal imaging time was 34 minutes. After 24 hours, the SLN imaging rate remained 100%, while those of the secondary and the tertiary LNs increased from 0% (6 hours) and 0% (6 hours) to 10% (12 hours) and 10% (12 hours) to 20% (24 hours) and 10% (24 hours), respectively. Conclusion: ICG-rituximab localized to the SLN without imaging from the secondary or tertiary LNs within 6 hours. The optimal ICG dose was 0.12 μg, and the optimal interval for SLN detection was 34 minutes to 6 hours post-injection. This novel receptor-targeted tracer is of great value to clinical research and application.

Internal Mammary Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer

Zhao Bi,Peng Chen,Jingjing Liu,Yanbing Liu,Pengfei Qiu,Qifeng Yang,Weizhen Zheng,Yongsheng Wang 한국유방암학회 2018 Journal of breast cancer Vol.21 No.4

Purpose: The definition of nodal pathologic complete response (pCR) after a neoadjuvant chemotherapy (NAC) just included the evaluation of axillary lymph node (ALN) without internal mammary lymph node. This study aimed to evaluate the feasibility of internal mammary-sentinel lymph node biopsy (IM-SLNB) in patients with breast cancer who underwent NAC. Methods: From November 2011 to 2017, 179 patients with primary breast cancer who underwent operation after NAC were included in this study. All patients received radiotracer injection with modified injection technology. IM-SLNB would be performed on patients with internal mammary sentinel lymph node (IMSLN) visualization. Results: Among the 158 patients with cN+ disease, the rate of nodal pCR was 36.1% (57/158). Among the 179 patients, the visualization rate of IMSLN was 31.8% (57/179) and was 12.3% (7/57) and 87.7% (50/57) among those with cN0 and cN+ disease, respectively. Furthermore, the detection rate of IMSLN was 31.3% (56/179). The success rate of IM-SLNB was 98.2% (56/57). The IMSLN metastasis rate was 7.1% (4/56), and all of them were accompanied by ALN metastasis. The number of positive ALNs in patients with IMSLN metastasis was 3, 6, 8, and 9. The pathology nodal stage had been changed from pN1/ pN2 to pN3b. The pathology stage had been changed from IIA/ IIIA to IIIC. Conclusion: Patients with visualization of IMSLN should perform IM-SLNB after NAC, especially for patients with cN+ disease, in order to complete lymph nodal staging. IM-SLNB could further improve the definition of nodal pCR and guide the internal mammary node irradiation.

Predicting Pathological Complete Response in Breast Cancer After Two Cycles of Neoadjuvant Chemotherapy by Tumor Reduction Rate: A Retrospective Case-Control Study

Litong Yao,Xiaoyan Liu,Mozhi Wang,Keda Yu,Shouping Xu,Pengfei Qiu,Zhidong Lv,Xinwen Zhang,Yingying Xu 한국유방암학회 2023 Journal of breast cancer Vol.26 No.2

Purpose: We aimed to identify effectiveness-associated indicators and evaluate the optimal tumor reduction rate (TRR) after two cycles of neoadjuvant chemotherapy (NAC) in patients with invasive breast cancer. Methods: This retrospective case-control study included patients who underwent at least four cycles of NAC at the Department of Breast Surgery between February 2013 and February 2020. A regression nomogram model for predicting pathological responses was constructed based on potential indicators. Results: A total of 784 patients were included, of whom 170 (21.68%) reported pathological complete response (pCR) after NAC and 614 (78.32%) had residual invasive tumors. The clinical T stage, clinical N stage, molecular subtype, and TRR were identified as independent predictors of pCR. Patients with a TRR > 35% were more likely to achieve pCR (odds ratio, 5.396; 95% confidence interval [CI], 3.299–8.825). The receiver operating characteristic (ROC) curve was plotted using the probability value, and the area under the ROC curve was 0.892 (95% CI, 0.863–0.922). Conclusion: TRR > 35% is predictive of pCR after two cycles of NAC, and an early evaluation model using a nomogram based on five indicators, age, clinical T stage, clinical N stage, molecular subtype, and TRR, is applicable in patients with invasive breast cancer.