Three-dimensional dynamics of vortex-induced vibration of a pipe with internal flow in the subcritical and supercritical regimes

Jinlong Duan,Ke Chen,Yunxiang You,Renfeng Wang,Jinlong Li 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.6

The Three-dimensional (3-D) dynamical behaviors of a fluid-conveying pipe subjected to vortex-induced vibration are investigated with different internal flow velocity v. The values of the internal flow velocity are considered in both subcritical and supercritical regimes. During the study, the 3-D nonlinear equations are discretized by the Galerkin method and solved by a fourth-order Runge-Kutta method. The results indicate that for a constant internal flow velocity v in the subcritical regime, the peak Cross-flow (CF) amplitude increases firstly and then decrease accompanied by amplitude jumps with the increase of the external reduced velocity. While two response bands are observed in the In-line (IL) direction. For the dynamics in the lock-in condition, 3-D periodic, quasi-periodic and chaotic vibrations are observed. A variety of CF and IL responses can be detected for different modes with the increase of v. For the cases studied in the supercritical regime, the dynamics shows a great diversity with that in the subcritical regime. Various dynamical responses, which include 3-D periodic, quasi-periodic as well as chaotic motions, are found while both CF and IL responses are coupled while v is beyond the critical value. Besides, the responses corresponding to different couples of m1 and m2 are obviously distinct from each other.

Three-dimensional dynamics of vortex-induced vibration of a pipe with internal flow in the subcritical and supercritical regimes

Duan, Jinlong,Chen, Ke,You, Yunxiang,Wang, Renfeng,Li, Jinlong The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.6

The Three-dimensional (3-D) dynamical behaviors of a fluid-conveying pipe subjected to vortex-induced vibration are investigated with different internal flow velocity ${\nu}$. The values of the internal flow velocity are considered in both subcritical and supercritical regimes. During the study, the 3-D nonlinear equations are discretized by the Galerkin method and solved by a fourth-order Runge-Kutta method. The results indicate that for a constant internal flow velocity ${\nu}$ in the subcritical regime, the peak Cross-flow (CF) amplitude increases firstly and then decrease accompanied by amplitude jumps with the increase of the external reduced velocity. While two response bands are observed in the In-line (IL) direction. For the dynamics in the lock-in condition, 3-D periodic, quasi-periodic and chaotic vibrations are observed. A variety of CF and IL responses can be detected for different modes with the increase of ${\nu}$. For the cases studied in the supercritical regime, the dynamics shows a great diversity with that in the subcritical regime. Various dynamical responses, which include 3-D periodic, quasi-periodic as well as chaotic motions, are found while both CF and IL responses are coupled while ${\nu}$ is beyond the critical value. Besides, the responses corresponding to different couples of ${\mu}_1$ and ${\mu}_2$ are obviously distinct from each other.

Coupled Analysis of Pedodiversity and Surface Water Diversity for Case Areas from the Developed East and Less Developed Central China

Jinlong Duan,Xuelei Zhang,Guangping Xiao 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

FOXK1 regulates epithelial-mesenchymal transition and radiation sensitivity in nasopharyngeal carcinoma via the JAK/STAT3 signaling pathway

Duan Liqun,Huang Jinlong,Zhang Yong,Pi Guoliang,Ying Xiaofang,Zeng Fanyu,Hu Desheng,Ma Jia 한국유전학회 2023 Genes & Genomics Vol.45 No.6

Background Nasopharyngeal carcinoma (NPC) is the most common head and neck tumor in China. Forkhead box (FOX) proteins have 19 subfamilies, which can maintain cell metabolism, regulate cell cycle and cell growth, etc. FOXK1 is a member of the FOX family, and studies have found that FOXK1 is closely related to tumors. Objective This experiment aims to study the effects of FOXK1 interference on proliferation, apoptosis, invasion, epithelial-mesenchymal transition (EMT), and radiosensitivity, by regulating the Janus kinas/signal translator and activator of the transfer 3 (JAK/STAT3) pathway. Methods The expression of FOXK1 was detected via immunohistochemistry using clinical nasopharyngeal carcinoma tissues and adjacent tissues. The relationship between FOXK1 expression and tumor stage was subsequently evaluated. The colony formation rate was calculated through the colony formation experiment. Cell apoptosis and cell cycle distribution were detected using flow cytometry, while cell invasion was detected using the Transwell method. The number of cells in the nucleus of each group after 30 min, 4 h, and 24 h of radiotherapy with the 2 Gy dose was counted using immunofluorescence under γ-H2AX focal points of a laser confocal microscope. Results FOXK1 is clearly expressed in the patients’ cancer tissues. The expression of FOXK1 was significantly correlated with the patient’s sex. FOXK1 interference or Peficitinib can upregulate the apoptosis rate of 5-8 F and CNE-2 cells; increase the G2 phase of cells; and inhibit the invasion, migration, and EMT of cells. At the same time, FOXK1 interference can downregulate the protein expression of p-JAK1, p-JAK2, and p-STAT3 in cells. Interference from FOXK1 or Peficitinib alone can reduce the rate of cell colony formation under different radiation doses, and enhance the green fluorescence intensity of γ-H2AX in the nucleus after 4 and 24 h of the 2 Gy dose of radiotherapy. These results are optimal when FOXK1 interference and Peficitinib are used together. Conclusion FOXK1 interference in NPC cells can regulate EMT through the JAK/STAT3 signal pathway, enhance the radiosensitivity of cells, and thus inhibit tumor cell progression.

Long Noncoding RNA HEIH Promotes Colorectal Cancer Tumorigenesis via Counteracting miR-939Mediated Transcriptional Repression of Bcl-xL

Chunhui Cui,Duanyang Zhai,Lianxu Cai,Qiaobin Duan,Lang Xie,Jinlong Yu 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose Studies have found that long noncoding RNA HEIH (lncRNA-HEIH) is upregulated and facilitates hepatocellular carcinoma tumor growth. However, its clinical significances, roles, and action mechanism in colorectal cancer (CRC) remains unidentified. Materials and Methods lncRNA-HEIH expression in CRC tissues and cell lines was measured by quantitative realtime polymerase chain reaction. Cell Counting Kit-8, ethynyl deoxyuridine incorporation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and nude mice xenografts assays were performed to investigate the roles of lncRNA-HEIH. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to investigate the action mechanisms of lncRNA-HEIH. Results In this study, we found that lncRNA-HEIH is significantly increased in CRC tissues and cell lines. lncRNA-HEIH expression is positively associated with tumor size, invasion depth, and poor prognosis of CRC patients. Enhanced expression of lncRNA-HEIH promotes CRC cell proliferation and decreases apoptosis in vitro, and promotes CRC tumor growth in vivo. Whereas knockdown of lncRNA-HEIH inhibits CRC cell proliferation and induces apoptosis in vitro, and suppresses CRC tumor growth in vivo. Mechanistically, lncRNA-HEIH physically binds to miR-939. The interaction between lncRNA-HEIH and miR-939 damages the binding between miR-939 and nuclear factor B (NF-B), increases the binding of NF-B to Bcl-xL promoter, and promotes the transcription and expression of Bcl-xL. Moreover, Bcl-xL expression is positively associated with lncRNA-HEIH in CRC tissues. Blocking the interaction between lncRNA-HEIH and miR-939 abolishes the effects of lncRNA-HEIH on CRC tumorigenesis. Conclusion This study demonstrated that lncRNA-HEIH promotes CRC tumorigenesis through counteracting miR-939mediated transcriptional repression of Bcl-xL, and suggested that lncRNAHEIH may serve as a prognostic biomarker and therapeutic target for CRC.

Experimental study of internal solitary wave loads on the semi-submersible platform

Zhang Jingjing,Liu Yi,Chen Ke,You Yunxiang,Duan Jinlong 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1

A prediction method, based on the Morison equation as well as Froude-Krylov formula, is presented to simulate the loads acting on the columns and caissons of the semi-submersible platform induced by Internal SolitaryWave (ISW) respectively. Combined with the experimental results, empirical formulas of the drag and inertia coefficients in Morison equation can be determined as a function of the Keulegan eCarpenter (KC) number, Reynolds number (Re) and upper layer depth h1=h respectively. The experimental and calculated results are compared. And a good agreement is observed, which proves that the present prediction method can be used for analyzing the ISW-forces on the semi-submersible platform. Moreover, the results also demonstrate the layer thickness ratio has a significant effect upon the maximum horizontal forces on the columns and caissons, but both minimum horizontal and vertical forces are scarcely affected. In addition, the incoming wave directions may also contribute greatly to the values of horizontal forces exerted on the caissons, which can be ignored in the vertical force analysis.