Simulation and assessment of gas dispersion above sea from a subsea release: A CFD-based approach

Xinhong Li,Guoming Chen,Renren Zhang,Hongwei Zhu,Changhang Xu 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

This paper presents a comprehensive simulation and assessment of gas dispersion above sea from a subsea release using a Computational Fluid Dynamics (CFD) approach. A 3D CFD model is established to evaluate the behavior of flammable gas above sea, and a jack-up drilling platform is included to illustrate the effect of flammable gas cloud on surface vessels. The simulations include a matrix of scenarios for different surface release rates, distances between surface gas pool and offshore platform, and wind speeds. Based on the established model, the development process of flammable gas cloud above sea is predicted, and the dangerous area generated on offshore platform is assessed. Additionally, the effect of some critical factors on flammable gas dispersion behavior is analyzed. The simulations produce some useful outputs including the detailed parameters of flammable gas cloud and the dangerous area on offshore platform, which are expected to give an educational reference for conducting a prior risk assessment and contingency planning.

Simulation and assessment of gas dispersion above sea from a subsea release: A CFD-based approach

Li, Xinhong,Chen, Guoming,Zhang, Renren,Zhu, Hongwei,Xu, Changhang The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

This paper presents a comprehensive simulation and assessment of gas dispersion above sea from a subsea release using a Computational Fluid Dynamics (CFD) approach. A 3D CFD model is established to evaluate the behavior of flammable gas above sea, and a jack-up drilling platform is included to illustrate the effect of flammable gas cloud on surface vessels. The simulations include a matrix of scenarios for different surface release rates, distances between surface gas pool and offshore platform, and wind speeds. Based on the established model, the development process of flammable gas cloud above sea is predicted, and the dangerous area generated on offshore platform is assessed. Additionally, the effect of some critical factors on flammable gas dispersion behavior is analyzed. The simulations produce some useful outputs including the detailed parameters of flammable gas cloud and the dangerous area on offshore platform, which are expected to give an educational reference for conducting a prior risk assessment and contingency planning.

Preventive effect of Lactobacillus plantarum HFY09 on HCl/ethanol-induced gastric injury in mice

Li Fang,Sun Hailan,Ran Guangjun,Liu Xinhong,Yi Ruokun,Tan Fang,Zhao Xin,Liu Huazhi 한국응용생명화학회 2020 Applied Biological Chemistry (Appl Biol Chem) Vol.63 No.5

The aim of this study was to investigate the effect of Lactobacillus plantarum HFY09 on gastric injury induced by HCl/ ethanol in Kunming mice. The results showed that HFY09-H inhibited any increases in gastric juice volume, maintained the normal pH value of gastric acid, and reduced the damage caused to the gastric mucosa and gastric wall, the inhibition rate on the injury area reaches 63.70%. Compared with the negative control group, HFY09 increased the levels of serum somatostatin (SS) and vasoactive intestinal peptide (VIP), and also decreased the levels of substance P (SP), endothelin-1 (ET-1), interleukin-6 (IL-6), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). In addition, real time fluorescent quantitative PCR (Q-PCR) also confirmed that high-dose HFY09 ( 109 CFU/kg/ day) upregulated the mRNA expression of copper/zinc superoxide dismutase (Cu/Zn-SOD), manganese superoxide dismutase (Mn-SOD), catalase (CAT), endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS), and downregulated the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). At the same time, the results of the HFY09 treatment group were similar to those of the ranitidine treatment group. These results indicate that HFY09 can prevent gastric injury induced by HCl/ethanol in vivo. Therefore, HFY09 may play a potential role in the treatment of gastric diseases.

Physiological and biochemical characterization of sheepgrass (Leymus chinensis) reveals insights into photosynthetic apparatus coping with low-phosphate stress conditions

Lingyu Li,Haomeng Yang,Weibo Ren,Bei Liu,Dongmei Cheng,Xinhong Wu,Jirui Gong,Lianwei Peng,Fang Huang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.4

Sheepgrass [Leymus chinensis (Trin.) Tzvel] is a valuble forage plant highly significant to regional grassland productivity of Euro-Asia steppes. Although effects of environmental stress including drought have been studied, impact of nutrient deficiency in particular phosphate (Pi), one of the essential macronutrient, is not reported. Here, we investigated low-Pi effect on its photosynthetic apparatus via physiological and biochemical analysis. We show that PSII activity was significantly reduced based on chlorophyll fluorescence measurements. We observed decreased amount of core proteins of PSII by immunoblot analysis. Further analysis of thylakoid membranes using 2D-BN/SDS-PAGE and immunoblot detection demonstrated that the amount of PSII complexes was closely correlated with the Pi levels within the range. Together with reduced number of thylakoid grana stackings observed, we suggest that the maintenance of PSII is impaired under Pi-limited condition. Moreover, enzyme activity assays revealed that the activity of several ROS scavenger enzymes was stimulated by low-Pi treatment. Based on these experimental results we conclude that PSII is the component of photosynthetic apparatus most sensitive to Pi supply and the enhanced anti-ROS activity is mainly subjective to protection of PSII against low Pi-induced photo-oxidative stress in the organism.

Sensorless Control Strategy of Permanent Magnet Synchronous Motor Based on Fuzzy Sliding Mode Controller and Fuzzy Sliding Mode Observer

Zou Xinhong,Ding Hongchang,Li Jinhong 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

This paper proposes a permanent magnet synchronous motor sensorless control strategy based on fuzzy sliding mode controller and fuzzy sliding mode observer. In order to improve the response speed of the system and the anti-interference ability of the system, a sliding mode controller (SMC) is used to replace the PI regulator in the speed loop. In order to suppress the chattering caused by sliding mode variable structure control and reduce the error caused by chattering, the SMC and sliding mode observer (SMO) are improved. An integral sliding mode surface is used in the SMC, and a continuous saturation function is used instead of a discontinuous sign function. The square of the speed error is introduced in the switch term of the exponential approaching law to improve the dynamic quality of approaching motion. The switching function in the SMO also uses a saturation function to suppress chattering caused by switching. Fuzzy rules are established to adaptively adjust the switching gain of the SMO and the parameters in the SMC’s reaching law, which further improves the performance of the control system. Simulations and experiments prove that the proposed control strategy has the characteristics of small chattering, fast response speed, and strong robustness.

Identification of genes involved in inbreeding depression of reproduction in Langshan chickens

Xue Qian,Li Guohui,Cao Yuxia,Yin Jianmei,Zhu Yunfen,Zhang Huiyong,Zhou Chenghao,Shen Haiyu,Dou Xinhong,Su Yijun,Wang Kehua,Zou Jianmin,Han Wei 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.6

Objective: Inbreeding depression of reproduction is a major concern in the conservation of native chicken genetic resources. Here, based on the successful development of strongly inbred (Sinb) and weakly inbred (Winb) Langshan chickens, we aimed to evaluate inbreeding effects on reproductive traits and identify candidate genes involved in inbreeding depression of reproduction in Langshan chickens. Methods: A two-sample t-test was performed to estimate the differences in phenotypic values of reproductive traits between Sinb and Winb chicken groups. Three healthy chickens with reproductive trait values around the group mean values were selected from each of the groups. Differences in ovarian and hypothalamus transcriptomes between the two groups of chickens were analyzed by RNA sequencing (RNA-Seq). Results: The Sinb chicken group showed an obvious inbreeding depression in reproduction, especially for traits of age at the first egg and egg number at 300 days (p<0.01). Furthermore, 68 and 618 differentially expressed genes (DEGs) were obtained in the hypothalamus and ovary between the two chicken groups, respectively. In the hypothalamus, DEGs were mainly enriched in the pathways related to vitamin metabolism, signal transduction and development of the reproductive system, such as the riboflavin metabolism, Wnt signaling pathway, extracellular matrix-receptor interaction and focal adhesion pathways, including stimulated by retinoic acid 6, serpin family F member 1, secreted frizzled related protein 2, Wnt family member 6, and frizzled class receptor 4 genes. In the ovary, DEGs were significantly enriched in pathways associated with basic metabolism, including amino acid metabolism, oxidative phosphorylation, and glycosaminoglycan degradation. A series of key DEGs involved in folate biosynthesis (gamma-glutamyl hydrolase, guanosine triphosphate cyclohydrolase 1), oocyte meiosis and ovarian function (cytoplasmic polyadenylation element binding protein 1, structural maintenance of chromosomes 1B, and speedy/RINGO cell cycle regulator family member A), spermatogenesis and male fertility (prostaglandin D2 synthase 21 kDa), Mov10 RISC complex RNA helicase like 1, and deuterosome assembly protein 1) were identified, and these may play important roles in inbreeding depression in reproduction. Conclusion: The results improve our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction and provide a theoretical basis for the conservation of species resources. Objective: Inbreeding depression of reproduction is a major concern in the conservation of native chicken genetic resources. Here, based on the successful development of strongly inbred (Sinb) and weakly inbred (Winb) Langshan chickens, we aimed to evaluate inbreeding effects on reproductive traits and identify candidate genes involved in inbreeding depression of reproduction in Langshan chickens.Methods: A two-sample t-test was performed to estimate the differences in phenotypic values of reproductive traits between Sinb and Winb chicken groups. Three healthy chickens with reproductive trait values around the group mean values were selected from each of the groups. Differences in ovarian and hypothalamus transcriptomes between the two groups of chickens were analyzed by RNA sequencing (RNA-Seq).Results: The Sinb chicken group showed an obvious inbreeding depression in reproduction, especially for traits of age at the first egg and egg number at 300 days (p<0.01). Furthermore, 68 and 618 differentially expressed genes (DEGs) were obtained in the hypothalamus and ovary between the two chicken groups, respectively. In the hypothalamus, DEGs were mainly enriched in the pathways related to vitamin metabolism, signal transduction and development of the reproductive system, such as the riboflavin metabolism, Wnt signaling pathway, extracellular matrix-receptor interaction and focal adhesion pathways, including stimulated by retinoic acid 6, serpin family F member 1, secreted frizzled related protein 2, Wnt family member 6, and frizzled class receptor 4 genes. In the ovary, DEGs were significantly enriched in pathways associated with basic metabolism, including amino acid metabolism, oxidative phosphorylation, and glycosaminoglycan degradation. A series of key DEGs involved in folate biosynthesis (gamma-glutamyl hydrolase, guanosine triphosphate cyclohydrolase 1), oocyte meiosis and ovarian function (cytoplasmic polyadenylation element binding protein 1, structural maintenance of chromosomes 1B, and speedy/RINGO cell cycle regulator family member A), spermatogenesis and male fertility (prostaglandin D2 synthase 21 kDa), Mov10 RISC complex RNA helicase like 1, and deuterosome assembly protein 1) were identified, and these may play important roles in inbreeding depression in reproduction.Conclusion: The results improve our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction and provide a theoretical basis for the conservation of species resources.

Estimating the Probability Density Function of Remaining Useful Life for Wiener Degradation Process with Uncertain Parameters

Guo Xie,Xin Li,Xi Peng,Fucai Qian,Xinhong Hei 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.11

The effective prediction of remaining useful life is essential to realize system failure diagnosis and health management. The existing researches often assume that the degradation model is constant or the degradation process is measurable. The accurate degradation model, however, usually can not be established, and the parametric variation and measurement error of the degradation process are unavoidable, which makes it hard to obtain the exact value for predicting the remaining useful life. Regarding this problem, on basis of the concept of first failure time, a real-time probability density function is derived for the Wiener degradation process with the uncertainty of parameters, the stochasticity of degradation process and the randomness of measurement error. The main steps are as follows: firstly, the degradation model with three kinds of uncertainties is established, and then the stochastic degradation state and the parameters of the uncertainty model are estimated by fusion Kalman/UFIR filter; then, the analytical expression of the probability density function of remaining useful life is deduced. Finally, the correctness and effectiveness of the proposed method are verified by a group of comparison experiments and Monte Carlo simulations.

Effect of gas composition on dispersion characteristics of blowout gas on offshore platform

Dongdong Yang,Guoming Chen,Jihao Shi,Xinhong Li 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

Gas composition has a significant impact on the dispersion behavior and accumulation characteristics of blowout gas. However, few public studies has investigated the corresponding effect of gas composition. Therefore, this study firstly builds the FLACS-based numerical model about an offshore drilling platform. Then several scenarios by varying the composition of blowout gas are simulated while the scenario with the composition of “Deepwater Horizon” accident is regarded as the benchmark. Furthermore, the effects of the gas composition on the flammable cloud volume, the influenced area of flammable cloud, the influenced area of hydrogen sulfide and the critical time of the hydrogen sulfide spreading to the living area are analyzed. The results demonstrate that gas composition is a driving factor for dispersion characteristics of blowout gas. All the results can give support to reduce the risk of the similar accidents incurred by real blowouts.

Effect of gas composition on dispersion characteristics of blowout gas on offshore platform

Yang, Dongdong,Chen, Guoming,Shi, Jihao,Li, Xinhong The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

Gas composition has a significant impact on the dispersion behavior and accumulation characteristics of blowout gas. However, few public studies has investigated the corresponding effect of gas composition. Therefore, this study firstly builds the FLACS-based numerical model about an offshore drilling platform. Then several scenarios by varying the composition of blowout gas are simulated while the scenario with the composition of "Deepwater Horizon" accident is regarded as the benchmark. Furthermore, the effects of the gas composition on the flammable cloud volume, the influenced area of flammable cloud, the influenced area of hydrogen sulfide and the critical time of the hydrogen sulfide spreading to the living area are analyzed. The results demonstrate that gas composition is a driving factor for dispersion characteristics of blowout gas. All the results can give support to reduce the risk of the similar accidents incurred by real blowouts.

A R2R3-type MYB transcription factor gene from soybean, GmMYB12, is involved in flavonoids accumulation and abiotic stress tolerance in transgenic Arabidopsis

Feibing Wang,Xuqin Ren,Fan Zhang,Mingyang Qi,Huiyun Zhao,Xinhong Chen,Yuxiu Ye,Jiayin Yang,Shuguang Li,Yi Zhang,Yuan Niu,Qing Zhou 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.3

The R2R3-type MYB transcription factors have been shown to increase flavonoids accumulation by regulating the expression of key enzyme genes related to flavonoid biosynthesis pathway. However, the roles and underlying mechanisms of the soybean GmMYB12 gene in regulation of flavonoids accumulation and tolerance to abiotic stresses are rarely known. In the present study, the GmMYB12 gene was isolated and its function was characterized. Sequence and yeast one-hybrid analyses showed that GmMYB12 contained two MYB domains and belonged to R2R3-MYB protein with transactivation activity. Subcellular localization analysis in onion epidermal cells indicated that GmMYB12 was localized to the nucleus. Overexpression of GmMYB12 increased the production of downstream flavonoids and the expression of related genes in the flavonoid biosynthesis pathway. It also improved resistance to salt and drought stresses during seed germination, root development, and growing stage. Further component and enzymatic analyses showed significant increases of proline content, pyrroline-5-carboxylate synthase (P5CS), superoxide dismutase (SOD), and peroxidase (POD) activities, as well as significant reduction of H2O2 and malonaldehyde (MDA) content under salt and drought stresses in transgenic plants. Meanwhile, the expression level of AtP5CS, AtSOD and AtPOD genes was up-regulated against salt and drought stresses. Together, our finding indicated that changing the expression level of GmMYB12 in plants alters the accumulation of flavonoids and regulates plantlet tolerance to abiotic stress by regulating osmotic balance, protecting membrane integrity and maintaining ROS homeostasis. The GmMYB12 gene has the potential to be used to increase the content of valuable flavonoids and improve the tolerance to abiotic stresses in plants