Design and Optimization of an Improved T-shape Linear Permanent Magnet Machines

Rong Guo,Wei He 한국자기학회 2023 Journal of Magnetics Vol.28 No.3

This paper presents an improved T-shape linear permanent magnet machine (T-LPMM) based on a traditional surface-mounted linear permanent magnet machine (SM-LPMM). The proposed topological structure aims to protect the surface of the permanent magnet from corrosion and enhance the rigidity against make highfrequency vibration. Firstly, the slotless magnetic field is predicted using finite-element method (FEM) with automatic scripting in MATLAB to consider the inset T-shape structure of PM. Then, the Schwarz-Christoffel (SC) mapping is adopted to calculate the slot effect. Afterward, a subdomain (SD) model is established to analyze the armature reaction, and Taguchi method is employed for optimization purposes. The optimized result is verified by FEM, and a comparison experiment is conducted between T-LPMM and SM-LPMM. The experimental demonstrate superior electromagnetic output performance of the proposed T-LPMM.

Effects of Grouting Defects in a Duct on the Bonding of Prestressing Strands

Rong Guo,Zhichao Zhen,Shaowei Zhao,Cunan Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

Insufficient grouting has a great effect on the bonding performance of pressing stand for a post-tensioned prestressed concrete beam, which leads to a decrease of beam’s bending capacity. This study focused on the influence of defects of local grouting length and grouting fullness on the prestressing strand’s bond performance. The prestressing strand pull-out test was used to evaluate the bonding performance of pressing stand with different defects of local grouting length and grouting fullness. The results indicate that two forms of grouting defects reduce the bonding properties of a prestressing strand, when the slip of the free end of prestressing strand is 0.12 mm (s = 0.12 mm), the bond stress decreases briefly. To analyze the bonding mechanism of the prepressing strand in duct, the bond stresses τ0 and τu at s = 0.12 mm and s = 25 mm were adopted as the characteristic parameters of bond stress to deduce the calculation formula of the bond strength by fitting the test data. A bond-slip constitutive model of prestressing strand in duct under two classes defects was proposed by improving the modified Eligehausen, Popov and Bertero (BPE) model of fiber reinforced polymer (FRP) rebars.

FRP Flexural Strengthened Concrete Member Design Method of Based on Early-Warning Fuses

Rong Guo,Shuo Ning,Shaowei Zhao,Minghao Wang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

The bearing capacity of members strengthened with prestressed carbon fiber reinforced plastic is improved significantly, however, the ductility of the members strengthened are reduced obviously. Moreover, no sign are observed before the failure and the failure process rapidly. The current study proposed a reinforcement method based on early-warning fuses theory to address this issue and took carbon fiber reinforced plastic as an example. First, it's necessary to determine the area of carbon fiber board and the application of prestressed in each part of the member (early-warning fuses part and load-bearing part). This needs to be determined by the basic safety reserve and the additional safety reserve of the carrying capacity, then the calculation formula are derived; second, designing six simulation beams and four test beams. Based on the comparison of the computation of the derived formula with the simulation and test results, the calculated values of the early-warning load agree well with the simulated and experimental values, and the calculated values of the ultimate load are less than the simulated and experimental values. This showed that the theoretical calculation method has high accuracy. In addition, various evaluation index prove that the members strengthened have sufficient reserves.

Multiple Effects of a Novel Epothilone Analog on Cellular Processes and Signaling Pathways Regulated by Rac1 GTPase in the Human Breast Cancer Cells

Rongguo Qiu,Li Tang 대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.2

The epothilones are a class of microtubule inhibitors that exhibit a strong antitumor activity. UTD2is a novel epothilone analog generated by genetic manipulation of the polyketide biosynthetic genecluster. This study investigated the effects of UTD2 on the actin cytoskeleton and its critical regulators,and the signaling pathways which are essential for cell motility, growth and survival in MCF-7 breastcancer cells. Results showed that UTD2 inhibited the cellular functions of actin cytoskeleton, suchas wound-closure, migration and invasion, as well as adhesion. Our study further demonstrated thatUTD2 suppressed Rac1 GTPase activation and reduced the activity of PAK1, which is a downstreameffector of Rac1, while the activity of Cdc42 was not affected. Additionally, the phosphorylation of p38and ERK were significantly inhibited, but the phosphorylation of JNK remained the same after UTD2treatment. Moreover, UTD2 inhibited the activity and mRNA expression of MMP-2, which plays akey role in cell motility. UTD2 also reduced the phosphorylation of Akt, which is an important signalingkinase regulating the cell survival through Rac1. Furthermore, UTD2 interrupted the synergy betweenRac1 and Raf in focus formation assays. Taken together, these results indicated that UTD2 exertedmultiple effects on the actin cytoskeleton and signaling pathways associated with Rac1. This studyprovided novel insights into the molecular mechanism of the antineoplastic and antimetastaticactivities of epothilones. Our findings also suggest that the signaling pathways regulated by Rac1 maybe evaluated as biomarkers for the response to therapy in clinical trials of epothilones.

Design of Four-Axis Winding Machine for Tapered Composite Pole Using Heated-Mandrel Curing

Jiazhong Xu,Rongguo Wang,Tao Sun,Qingmin Huang,Honghong Yang 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.1

Multiple Effects of a Novel Epothilone Analog on Cellular Processes and Signaling Pathways Regulated by Rac1 GTPase in the Human Breast Cancer Cells

Zhang, Hong,An, Fan,Tang, Li,Qiu, Rongguo The Korean Society of Pharmacology 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.2

The epothilones are a class of microtubule inhibitors that exhibit a strong antitumor activity. UTD2 is a novel epothilone analog generated by genetic manipulation of the polyketide biosynthetic gene cluster. This study investigated the effects of UTD2 on the actin cytoskeleton and its critical regulators, and the signaling pathways which are essential for cell motility, growth and survival in MCF-7 breast cancer cells. Results showed that UTD2 inhibited the cellular functions of actin cytoskeleton, such as wound-closure, migration and invasion, as well as adhesion. Our study further demonstrated that UTD2 suppressed Rac1 GTPase activation and reduced the activity of PAK1, which is a downstream effector of Rac1, while the activity of Cdc42 was not affected. Additionally, the phosphorylation of p38 and ERK were significantly inhibited, but the phosphorylation of JNK remained the same after UTD2 treatment. Moreover, UTD2 inhibited the activity and mRNA expression of MMP-2, which plays a key role in cell motility. UTD2 also reduced the phosphorylation of Akt, which is an important signaling kinase regulating the cell survival through Rac1. Furthermore, UTD2 interrupted the synergy between Rac1 and Raf in focus formation assays. Taken together, these results indicated that UTD2 exerted multiple effects on the actin cytoskeleton and signaling pathways associated with Rac1. This study provided novel insights into the molecular mechanism of the antineoplastic and antimetastatic activities of epothilones. Our findings also suggest that the signaling pathways regulated by Rac1 may be evaluated as biomarkers for the response to therapy in clinical trials of epothilones.

Age and petrogenesis of Mingshui-Shuangjingzi granites from the northern Beishan area, northwest China, and their implications for tectonic evolution

Wen Zhang,Victoria Pease,Qingpeng Meng,Rongguo Zheng,Tairan Wu 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.5

The Mingshui and Shuangjingzi granitic plutons are exposed in the northern Beishan area, in the southern Central Asia Orogenic Belt. U-Pb zircon dating indicates that Mingshui secondary intrusive lithosfacies and Shuangjingzi quartz monzodiorite formed at 328 ± 2 Ma and 272 ± 2 Ma, respectively. The former is composed of grey white monzogranites and potassic altered flesh red monzogranites. Geochemistry indicates they are calc-alkaline I-type granites. Shuangjingzi granites are mainly composed of unfractionated calc-alkaline I-type quartz monzodiorite, granodiorite and monzogranite. The Mingshui grey white monzogranites with negative initial εNd (–2.0 to –1.7) and moderate initial 87Sr/86Sr values (0.706740 to 0.710092) were probably derived from mixing of the depleted mantle (juvenile) component and the Palaeoproterozoic–Archean crust (or sedimentary) component and represent volcanic arc granites. The Shuangjingzi quartz monzodiorites are most likely derived from mafic to intermediate igneous protolith and represent post-collisional granites. This work, combined with the regional geology, suggests the Palaeo-Asian Ocean closed between 328 Ma and 272 Ma in the northern Beishan area.

Prediction of the Development of Pulmonary Fibrosis Using Serial Thin-Section CT and Clinical Features in Patients Discharged after Treatment for COVID-19 Pneumonia

Yu Minhua,Liu Ying,Xu Dan,Zhang Rongguo,Lan Lan,Xu Haibo 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.6

Objective: To identify predictors of pulmonary fibrosis development by combining follow-up thin-section CT findings and clinical features in patients discharged after treatment for COVID-19. Materials and Methods: This retrospective study involved 32 confirmed COVID-19 patients who were divided into two groups according to the evidence of fibrosis on their latest follow-up CT imaging. Clinical data and CT imaging features of all the patients in different stages were collected and analyzed for comparison. Results: The latest follow-up CT imaging showed fibrosis in 14 patients (male, 12; female, 2) and no fibrosis in 18 patients (male, 10; female, 8). Compared with the non-fibrosis group, the fibrosis group was older (median age: 54.0 years vs. 37.0 years, p = 0.008), and the median levels of C-reactive protein (53.4 mg/L vs. 10.0 mg/L, p = 0.002) and interleukin-6 (79.7 pg/L vs. 11.2 pg/L, p = 0.04) were also higher. The fibrosis group had a longer-term of hospitalization (19.5 days vs. 10.0 days, p = 0.001), pulsed steroid therapy (11.0 days vs. 5.0 days, p < 0.001), and antiviral therapy (12.0 days vs. 6.5 days, p = 0.012). More patients on the worst-state CT scan had an irregular interface (59.4% vs. 34.4%, p = 0.045) and a parenchymal band (71.9% vs. 28.1%, p < 0.001). On initial CT imaging, the irregular interface (57.1%) and parenchymal band (50.0%) were more common in the fibrosis group. On the worst-state CT imaging, interstitial thickening (78.6%), air bronchogram (57.1%), irregular interface (85.7%), coarse reticular pattern (28.6%), parenchymal band (92.9%), and pleural effusion (42.9%) were more common in the fibrosis group. Conclusion: Fibrosis was more likely to develop in patients with severe clinical conditions, especially in patients with high inflammatory indicators. Interstitial thickening, irregular interface, coarse reticular pattern, and parenchymal band manifested in the process of the disease may be predictors of pulmonary fibrosis. Irregular interface and parenchymal band could predict the formation of pulmonary fibrosis early.

The compressive behavior of CFRP laminates with delamination of different shapes using numerical and experimental approaches

Chunxing Hu,Yujiao Bai,Zhonghai Xu,Ruoyu Li,Rongguo Wang,Xiaodong He 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

Composite laminates often produce delamination due to a series of factors during the manufacture and service process. In order to research the effect of containing oblique elliptical and circular initial delamination damage on the compressive strength of composite laminates, numerical and experimental methods are used in this paper. Finite element models (FEMs) and the progressive damage subroutine USDFLD are developed to predict the damage initiation and extension behavior of the intralaminar of the laminate. Interlaminar damage is predicted based on cohesive zone models (CZM). At the same time, four compression tests containing different initial delamination damage are performed. The results show that experimental measurements of compression tests concur with the numerical predictions and validate the FEMs. The strength and stiffness of the specimens gradually decrease with the increase of the initial delamination area. It reveals that, for the compression process, the delamination damage extends from the edge of the initial damage to the surroundings. The bearing capacity of the composite laminates is mainly determined by the material properties of the fibers and matrix, rather than the initial delamination.

Differential Effects of Tautomycetin and Its Derivatives on Protein Phosphatase Inhibition, Immunosuppressive Function and Antitumor Activity

Mingshan Niu,Yan Sun,Bo Liu,Li Tang,Rongguo Qiu 대한약리학회 2012 The Korean Journal of Physiology & Pharmacology Vol.16 No.2

In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured in vivo phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn’t correlate with its in vivo PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC’s important biological functions.