Numerical investigation of heat transfer characteristics for Subsea Xmas tree assembly

Biao Hu,Hongwu Zhu,Kuang Ding,Fangling Xu,Youjiang Zhang 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

This study focuses on the heat transfer characteristic of a horizontal subsea Xmas tree assembly at a high spatial resolution. Computationalfluid dynamics (steady Reynolds-averaged Navier-Stokes) in combination with Low Reynolds number modelling (LRNM) isadopted for heat transfer analysis, which has been validated against a full scale underwater gate valve heat transfer experiment with goodagreements. The characteristics of cold sea water flowing through the subsea tree, and of convection heat transfer between the subsea treeand ambient cold water are obtained. The typical “hot spots,” which have high Convection heat transfer coefficient (CHTC) and creategreat large amounts of heat loss, are numerically determined. Under the designed water depth, the effects of installation orientation, seawater velocity, and inner oil temperature on convection heat transfer are investigated as well. Such work is significant for thermal designof the subsea tree to increase structural reliability and flow assurance level.

Experimental Investigation on Damage Behavior of Polypropylene Fiber Reinforced Concrete under Compression

Lihua Xu,Biao Li,Xiaoxiao Ding,Yin Chi,Changning Li,Biao Huang,Yuchuan Shi 한국콘크리트학회 2018 International Journal of Concrete Structures and M Vol.12 No.7

This paper presents an experimental investigation on the stress–strain behavior and the damage mechanism of polypropylene fiber reinforced concrete (PFRC) under monotonic and cyclic compression. Fifty-four specimens for different fiber volume fractions and aspect ratios were tested. Acoustic emission (AE) technique was used to monitor the damage progression. The damage mechanism of concrete was analyzed based on the AE parametric analysis. The results show that the incorporation of polypropylene fiber (PF) has a positive effect on the monotonic and cyclic behaviors of concrete, especially for the post-cracking branch. The toughness and ultimate strain are enhanced and the performance degradation in terms of elastic stiffness and strength is alleviated by the addition of PF. However, PF has little influences on the plastic strain, and the damage process of concrete is mainly driven by the envelope strain. The effect of fiber volume fraction on the cyclic behavior of concrete shows more pronounced than that of aspect ratio. In addition, it is found from AE results that the damage, closely related to AE events, has a quick evolution just after the peak stress, with the AE hits having a concentrated release. The total amount of AE hits increases with increasing fiber volume fraction due to fiber pullout and sliding, while the concrete with fiber aspect ratio of 280 reaches the largest amount. Meanwhile, as substantiated by AE, the failure of PFRC shows an obvious shear mode, with shear cracks dominating the damage progression. Finally, a damage elasto-plastic model is developed to predict the monotonic and cyclic responses of PFRC and the prediction yields a fairly close estimation with experimental results.

Stability of the m/n=1/1 mode during the ramp phase of the sawtooth oscillations at different phase angles of the lower hybrid wave on the HT-7 tokamak

youwen Sun,Baonian Wan,Biao Shen,Bojiang Ding,Haiqing Liu,Jinping Qian,Liqun Hu,Zhongyong Chen 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

The stability of the m/n = 1/1 mode (named “mid-oscillation”) during the ramp phase of the sawtooth oscillations in different current profiles has been investigated in a recent experiment. Modification of the local current density profile in the central region was obtained by changing the spectrum of the parallel refractive index Nk of the lower hybrid wave (LHW) with other parameters fixed. This shows that the amplitude and the growth rate of the mid-oscillation decrease with increasing peak value of the parallel refractive index Npeak k and the mode disappears during most of the sawtooth rampphases when Npeak k 3.15. This result directly demonstrates that the mode is mainly destabilized by the local current density gradient

Evaluation of Liver Metastases Using Contrast-Enhanced Ultrasound: Enhancement Patterns and Influencing Factors

( Wen Tao Kong ),( Zheng Biao Ji ),( Wen Ping Wang ),( Hao Cai ),( Bei Jian Huang ),( Hong Ding ) 대한소화기학회 2016 Gut and Liver Vol.10 No.2

Background/Aims: To evaluate the enhancement patterns of liver metastases and their influencing factors using dynamic contrast-enhanced ultrasound (CEUS). Methods: A total of 240 patients (139 male and 101 female; 58.5±11.2 years of age) diagnosed with liver metastases in our hospital were enrolled in this study to evaluate tumor characteristics using CEUS. A comparison of enhancement patterns with tumor size and primary tumor type was performed using the chi-square test. The differences between quantitative variables were evaluated with the independent-sample t-test and one-way analysis of variance. Results: The enhancement patterns of liver metastases on CEUS were categorized as diffuse homogeneous hyperenhancement (133/240, 55.4%), rim-like hyperenhancement (80/240, 33.3%), heterogeneous hyperenhancement (10/240, 4.2%), and isoenhancement (17/240, 7.1%). There were significant differences in the enhancement patterns during the arterial phase based on the nodule size (p=0.001). A total of 231 of the nodules showed complete washout during the portal phase, and 237 nodules were hypoenhanced during the delayed phase. The washout time was correlated with tumor vascularity, with a longer washout time observed in hypervascular metastases compared to hypovascular metastases (p=0.033). Conclusions: Diffuse homogeneous hyperenhancement followed by rapid washout was the most common enhancement pattern of liver metastases on CEUS and was affected by the nodule size and tumor vascularity. Small metastases were prone to show diffuse homogeneous hyperenhancement. Hypervascular metastases showed a significantly longer washout time compared to hypovascular metastases. (Gut Liver 2016;10:283-287)

Icariside II Promotes the Differentiation of Adipose Tissue-Derived Stem Cells to Schwann Cells to Preserve Erectile Function after Cavernous Nerve Injury

Zheng, Tao,Zhang, Tian-biao,Wang, Chao-liang,Zhang, Wei-xing,Jia, Dong-hui,Yang, Fan,Sun, Yang-yang,Ding, Xiao-ju,Wang, Rui Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.6

Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

Icariside II Promotes the Differentiation of Adipose Tissue-Derived Stem Cells to Schwann Cells to Preserve Erectile Function after Cavernous Nerve Injury

Tao Zheng,Tian-biao Zhang,Chao-liang Wang,Wei-xing Zhang,Dong-hui Jia,Fan Yang,Yang-yang Sun,Xiao-ju Ding,Rui Wang 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.6

Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs’ proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by up-regulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II pro-motes the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

Dynamic analysis for gene expression profiles of endothelial colony forming cells under hypoxia

De-Cai Yu,Wen-Du Feng,Xian-Biao Shi,hi-Yong Wang,Wei Ge,Chun-Ping Jiang,Xi-Tai Sun,Yi-Tao Ding 한국유전학회 2013 Genes & Genomics Vol.35 No.4

Previous studies have shown that endothelial colony forming cells (ECFCs) play an important role in the neovascularization of tumors. Hypoxia is emphasized as an important promoter of angiogenesis. However, little is known about genome-wide transcriptional regulation of ECFCs under hypoxic conditions. In this study, gene expression profiles in ECFCswere evaluated under hypoxic conditions for 3, 6, 12, 24,and 48 h, using Affymetrix U133 plus 2.0 chip microarray. 1,103 hypoxia-regulated genes were filtered, with 379(0.693 %) genes up-regulated and 724 (1.32 %) genes downregulated. Most of the up-regulated genes were involved in apoptosis, cell proliferation, or metabolic processes, while most of the down-regulated genes were involved in cell adherence,cell cycle,DNAandmRNAmetabolic processes,multi-cellular organism development, protein metabolic processes, response to stress, signal transduction, or transport. This expression profile is ECFC-specific, because it is significantly different from those of endothelial cells and smooth muscle cells under hypoxic conditions. Moreover, hypoxia-regulated apoptosis in ECFCs is mainly related with the mitochondrial pathway (p53-BAX-Caspase-9) and the death receptor pathway (FASCaspase-8-Caspase-3). MAPK pathway is activated in ECFCs under hypoxic conditions. The differentially expressed genes of ECFCs were identified under hypoxic conditions, and related with cell apoptosis, cell cycle and MAPK pathways, shedding light on the mechanism of angiogenesis.

FNC, a Novel Nucleoside Analogue, Blocks Invasion of Aggressive Non-Hodgkin Lymphoma Cell Lines Via Inhibition of the Wnt/β-Catenin Signaling Pathway

Zhang, Yan,Wang, Chen-Ping,Ding, Xi-Xi,Wang, Ning,Ma, Fang,Jiang, Jin-Hua,Wang, Qing-Duan,Chang, Jun-Biao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Chemotherapy is the primary therapy for malignant lymphoma (ML). However, the clinical outcome is still far from satisfactory. Consequently, an understanding of the mechanism of modulating cancer cell invasion, migration and metastasis is important for the development of more effective chemotherapeutic agents. FNC, 2'-deoxy-2'-${\beta}$-fluoro-4'-azidocytidine, a novel cytidine analogue, has demonstrated significantly inhibitory effects on proliferation of several non-Hodgkin lymphoma (NHL) cell lines. A previous study indicated that FNC effectively inhibited the growth of Raji and JeKo-1 cells in dose-time dependent effects with $IC_{50}$ values of $0.2{\mu}M$ and $0.097{\mu}M$, respectively. This study was focused on investigating the anti-invasive properties of FNC on NHL cells and its potential mechanisms of action. Cell adhesion and transwell chamber assays were utilized to investigate the anti-invasive effects of FNC on Raji and JeKo-1 cells. Real-time PCR and Western blotting were employed to qualify the expression of ${\beta}$-catenin, the glycogen synthase kinase-3 beta (GSK-$3{\beta}$), E-cadherin vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The results revealed that FNC remarkably inhibited the adhesion, migration and invasion of two human aggressive non-Hodgkin lymphoma cell lines in a dose dependent manner. Furthermore, ${\beta}$-catenin, MMP-2, MMP-9, VEGF mRNA and protein levels were decreased after FNC treatment, while GSK-$3{\beta}$ and E-cadherin increased. Our studies thus provide evidence and a rationale that FNC may offer an effective chemotherapeutic agent by regulating the invasion and metastasis of aggressive non-Hodgkin lymphoma via inhibition of the Wnt/${\beta}$-catenin signaling pathway.

Molecular and Biochemical Characterization of a Novel Xylanase from Massilia sp. RBM26 Isolated from the Feces of Rhinopithecus bieti

( Bo Xu ),( Li Ming Dai ),( Jun Jun Li ),( Meng Deng ),( Hua Biao Miao ),( Jun Pei Zhou ),( Yue Lin Mu ),( Qian Wu ),( Xiang Hua Tang ),( Yun Juan Yang ),( Jun Mei Ding ),( Nan Yu Han ),( Zun Xi Huang 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37°C and could maintain at least 96% activity after being placed at 37°C for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, Km, Vmax, and kcat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

Reliable experimental data as a key factor for design of mechanical structures

Josip Brnic,Sanjin Krscanski,Marino Brcic,Lin Geng,Jitai Niu,Biao Ding 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.2

The experimentally determined mechanical behavior of the material under the prescribed service conditions is the basis of advanced engineering optimum design. To allow experimental data on the behavior of the material considered, uniaxial stress tests were made. The aforementioned tests have enabled the determination of mechanical properties of material at different temperatures, then, the material's resistance to creep at various temperatures and stress levels, and finally, insight into the uniaxial high cyclic fatigue of the material under different applied stresses for prescribed stress ratio. Based on fatigue tests, using modified staircase method, fatigue limit was determined. All these data contributes the reliability of the use of material in mechanical structures. Data representing mechanical properties are shown in the form of engineering stress-strain diagrams; creep behavior is displayed in the form of creep curves while fatigue of the material is presented in the form of S-N (maximum applied stress versus number of the cycles to failure) curve. Material under consideration was 18CrNi8 (1.5920) steel. Ultimate tensile strength and yield strength at room temperature and at temperature of 600°C: [,/=(/)MPa; .,/=(/)MPa], as well as endurance (fatigue) limit at room temperature and stress ratio of =−: (,,=− = 285.1MPa).