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Vibration control of a stay cable with a rotary electromagnetic inertial mass damper
Zhi Hao Wang,Yan Wei Xu,Hui Gao,Zheng Qing Chen,Kai Xu,Shun Bo Zhao 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.6
Passive control may not provide enough damping for a stay cable since the control devices are often restricted to a low location level. In order to enhance control performance of conventional passive dampers, a new type of damper integrated with a rotary electromagnetic damper providing variable damping force and a flywheel serving as an inertial mass, called the rotary electromagnetic inertial mass damper (REIMD), is presented for suppressing the cable vibrations in this paper. The mechanical model of the REIMD is theoretically derived according to generation mechanisms of the damping force and the inertial force, and further validated by performance tests. General dynamic characteristics of an idealized taut cable with a REIMD installed close to the cable end are theoretically investigated, and parametric analysis are then conducted to investigate the effects of inertial mass and damping coefficient on vibration control performance. Finally, vibration control tests on a scaled cable model with a REIMD are performed to further verify mitigation performance through the first two modal additional damping ratios of the cable. Both the theoretical and experimental results show that control performance of the cable with the REIMD are much better than those of conventional passive viscous dampers, which mainly attributes to the increment of the damper displacement due to the inertial mass induced negative stiffness effects of the REIMD. Moreover, it is concluded that both inertial mass and damping coefficient of an optimum REIMD will decrease with the increase of the mode order of the cable, and oversize inertial mass may lead to negative effect on the control performance.
Impact of cable sag on the efficiency of an inertial mass damper in controlling stay cable vibrations
Zhi-hao Wang,Hui Gao,Yan-wei Xu,Zheng-qing Chen,Hao Wang 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.1
Passive negative stiffness dampers (NSDs) that possess superior energy dissipation abilities, have been proved to be more efficient than commonly adopted passive viscous dampers in controlling stay cable vibrations. Recently, inertial mass dampers (IMDs) have attracted extensive attentions since their properties are similar to NSDs. It has been theoretically predicted that superior supplemental damping can be generated for a taut cable with an IMD. This paper aims to theoretically investigate the impact of the cable sag on the efficiency of an IMD in controlling stay cable vibrations, and experimentally validate superior vibration mitigation performance of the IMD. Both the numerical and asymptotic solutions were obtained for an inclined sag cable with an IMD installed close to the cable end. Based on the asymptotic solution, the cable attainable maximum modal damping ratio and the corresponding optimal damping coefficient of the IMD were derived for a given inertial mass. An electromagnetic IMD (EIMD) with adjustable inertial mass was developed to investigate the effects of inertial mass and cable sag on the vibration mitigation performance of two model cables with different sags through series of first modal free vibration tests. The results show that the sag generally reduces the attainable first modal damping ratio of the cable with a passive viscous damper, while tends to increase the cable maximum attainable modal damping ratio provided by the IMD. The cable sag also decreases the optimum damping coefficient of the IMD when the inertial mass is less than its optimal value. The theoretically predicted first modal damping ratio of the cable with an IMD, taking into account the sag generally, agrees well with that identified from experimental results, while it will be significantly overestimated with a taut-cable model, especially for the cable with large sag.
Tian-Hao Weng,Min-Ya Yao,Xiang-Ming Xu,Chen-Yu Hu,Shu-Hao Yao,Yi-Zhi Liu,Zhi-Gang Wu,Tao-Ming Tang,Pei-Fen Fu,Ming-Hai Wang,Hang-Ping Yao 대한암학회 2020 Cancer Research and Treatment Vol.52 No.3
Purpose Triple-negative breast cancer (TNBC) is highly malignant and has poor prognosis and a high mortality rate. The lack of effective therapy has spurred our investigation of new targets for treating this malignant cancer. Here, we identified RON (macrophage-stimulating 1 receptor) and MET (MET proto-oncogene, receptor tyrosine kinase) as a prognostic biomarker and therapeutic targets for potential TNBC treatment. Materials and Methods We analyzed RON and MET expression in 187 primary TNBC clinical samples with immunohistochemistry. We validated the targeted therapeutic effects of RON and MET in TNBC using three tyrosine kinase inhibitors (TKIs): BMS-777607, INCB28060, and tivantinib. The preclinical therapeutic efficacy of the TKIs was mainly estimated using a TNBC xenograft model. Results Patients with TNBC had widespread, abnormal expression of RON and MET. There was RON overexpression, MET overexpression, and RON and MET co-overexpression in 63 (33.7%), 63 (33.7%), and 43 cases (23.0%), respectively, which had poor prognosis and short survival. In vivo, the TKI targeting RON ant MET inhibited the activation of the downstream signaling molecules, inhibited TNBC cell migration and proliferation, and increased TNBC cell apoptosis; in the xenograft model, they significantly inhibited tumor growth and shrank tumor volumes. The TKI targeting RON and Met, such as BMS-777607 and tivantinib, yielded stronger anti-tumor effects than INCB28060. Conclusion RON and MET co-overexpression can be significant pathological characteristics in TNBC for poor prognosis. TKIs targeting RON and MET have stronger drug development potential for treating TNBC.
Xu Jiang He,Liu Qing Tian,AndrewB. Barron,Cui Guan,Hao Liu,Xiaobo Wu,Zhi Jiang Zeng 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.4
In a honey bee colony, worker bees rear a newqueen by providing herwith a larger cell inwhich to develop and alarge amount of richer food (royal jelly). Royal jelly and worker jelly (fed to developing worker larvae) differ interms of sugar, vitamin, protein and nucleotide composition. Here we examined whether workers attendingqueen andworker larvae are separate specialized sub-castes of the nurse bees.We collected nurse bees attendingqueen larvae (AQL) and worker larvae (AWL) and compared gene expression profiles of hypopharyngeal glandtissues, using Solexa/Illumina digital gene expression tag profiling (DGE). Significant differences in gene expressionwere found that included a disproportionate number of genes involved in glandular secretion and royal jellysynthesis. However behavioral observations showed that thesewere not two entirely distinct populations. Nurseworkers were observed attending both worker larvae and queen larvae, and there was no evidence of a specializedgroup of workers that preferentially or exclusively attended developing queens. Nevertheless, AQL attendedlarvaemore frequently compared toAWL, suggesting that nurses sampled attending queen larvaemay have beenthe most active nurses. This study serves as another example of the relationship between differences in gene expressionand behavioral specialisation in honey bees.