Numerical simulations and surrogate-based optimization of cavitation performance for an aviation fuel pump

Xing’an Zhao,Biao Huang,Tairan Chen,Guoyu Wang,Deming Gao,Jing Zhao 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

We used computational modeling to investigate the cavitation performance of an aviation fuel pump, and optimize structural parameters using the surrogate-based method. In the numerical simulation, a rotation-curvature correction was adapted to the k-ε turbulence model, and a four-component surrogate fuel was selected to reproduce the physical properties of the China RP-3 kerosene. Then the performance of the aviation fuel pump was predicted. In the optimization, based on the series of the numerical results, Surrogate-based analysis and optimization (SBAO) was used to optimize the structural parameters of the fuel pump (the variation of the outlet blade angle for the inducer △β b1 and the variation of the inlet blade angle for the impeller △β b2 ). The results show that the prediction of cavitation performance agrees well with the experimental data. The results show that cavitation areas are mainly distributed in the inlet of the inducer. The volume of cavities grows with the decreasing NPSHa. The head of the fuel pump has a sudden head-drop when NPSHa ≤ 5.64 m. Furthermore, the surrogate-based approach is available in structural optimization of the fuel pump. The cavitation performance of the optimized pump improved about 22 % with a little drop of head coefficient when △β b1 = 4.33° and △β b2 = 3.24°. The numerical approach employed in this paper can accurately predict the cavitating flow of the high rotating speed fuel pump and the surrogate-based method is available in the structural optimization for a better cavitation performance.

A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

Zheng Tan,Wei-hui Zhong,Bao Meng,Shi-chao Duan,Hong-chen Wang3,Xing-You Yao,Yu-hui Zheng 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

Recommendations on management of gynecological malignancies during the COVID-19 pandemic: perspectives from Chinese gynecological oncologists

Yingmei Wang,Shiqian Zhang,Lihui Wei,Zhongqiu Lin,Xinyu Wang,Jianliu Wang,Keqin Hua,Manhua Cu,Jiandong Wang,Shixuan Wang,Wen Di,Yudong Wang,Ruifang An,Mingrong Xi,Ruixia Guo,Qi Zhou,Xing Xie,Fengxia X 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.4

The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratorysyndrome coronavirus 2 has rapidly spread globally. Cancer patients are at a higher risk ofbeing infected with the coronavirus and are more likely to develop severe complications, ascompared to the general population. The increasing spread of COVID-19 presents challengesfor the clinical care of patients with gynecological malignancies. Concerted efforts should beput into managing gynecological malignancies in an orderly manner by strictly implementingthe measures that are specifically developed for controlling the spread of COVID-19. We havedrafted Recommendations on Management of Gynecological Malignancies during the COVID-19 Pandemicbased on our experience on controlling COVID-19 pandemic in China. We recommendthat patients with gynecological malignancies should be managed in hierarchical andindividualized manners in combination with local conditions related to COVID-19. Medicalcare decision should be balanced between controlling COVID-19 pandemic spread and timelydiagnosis and treatment for gynecologic oncology patients.

The association between couple relationship quality and sleep quality: a systematic review and meta-analysis

Xing Xing Wang,Qingxiu Lin,Ping Dong,Ya Bin Wei,Jia Jia Liu 한국간호과학회 2023 한국간호과학회 학술대회 Vol.2023 No.11

Investigation of the Structural Behaviour of RC Beam-Column Sub-frame Subjected to Progressive Collapse

Feiliang Wang,Sandeep Shah,Xiaoping Wang,Xing-Er Wang,Wang-Xi Zhang,Bo Pang,Jian Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

The aim of this study is to investigate the effects of varying design variables on the structural behaviour of reinforced concrete (RC) sub-frames under progressive collapse. A finite element modelling approach is presented and validated against the experimental results concerning a 2D frame (3 columns and 2 beams) and a 3D frame (4 columns and 3 beams). The performance of the RC sub-frame is discussed by choosing the scenarios of the exterior, interior, and multiple column loss, respectively, and by increasing the number of stories and bays. Further studies are conducted based on the numerical method to reveal the effect of beam longitudinal reinforcement ratio (BLRR), beam section depth (BSD), and concrete compression strength (CCS). The results show that both BLRR, CCS and BSD have a significant influence on the compressive arch action (CAA) capacity of the structure under progressive collapse, and the load-carrying capacity of the RC sub-frame increases with an increasing number of stories.

Optimal Operation of Regional Integrated Energy System Considering Integrated Demand Response and Exergy Efficiency

Wang Jing,Xing Haijun,Wang Huaxin,Xie Baojiang,Luo Yangfan 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

In order to further improve the energy consumption potential and system energy utilization effi ciency on the demand side of regional integrated energy system (RIES), taking into account economy and energy effi ciency, a RIES optimal operation model and strategy considering integrated demand response (IDR) and exergy effi ciency are proposed. Firstly, the IDR is modeled, the exergy effi ciency of RIES is analyzed, and an exergy effi ciency model considering IDR is established. Secondly the RIES multi-objective optimization model is established with the goal of the lowest economic cost and the highest exergy effi ciency. In order to obtain a series of Pareto frontier solutions with uniform distribution, the normal boundary intersection is used to solve the multi-objective. Finally, the system economic cost and exergy effi ciency under four diff erent scenarios are analyzed. A practical example is used to verify the proposed model. The results show that considering the comprehensive demand response in RIES can eff ectively reduce the system cost. Through multi-objective analysis, it is verifi ed that the reasonable addition of comprehensive demand response can further improve the system exergy effi ciency and stimulate the exergy consumption potential on the demand side.

Latilactobacillus curvatus BYB3 Isolated from Kimchi Alleviates Dextran Sulfate Sodium (DSS)-Induced Colitis in Mice by Inhibiting IL-6 and TNF-R1 Production

( Xing Wang ),( Dingyun Li ),( Ziyao Meng ),( Kiyeop Kim ),( Sejong Oh ) 한국미생물 · 생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.3

Recent studies have shown that probiotics have health-promoting effects, particularly intestinal immune modulation. In this study, we focused on the immunomodulatory properties of Latilactobacillus curvatus BYB3, formerly called Lactobacillus curvatus, isolated from kimchi. In a mouse model of 14-day dextran sulfate sodium (DSS)-induced colitis, treatment with L. curvatus BYB3 significantly decreased the disease activity index, colon length, and weight loss. Moreover, histological analyses showed that L. curvatus BYB3 protected the structural integrity of the intestinal epithelial layer and mucin-secreting goblet cells from DSS-induced damage, with only slight infiltration by immune cells. To evaluate the molecular mechanisms underlying L. curvatus BYB3-driven inhibition of interleukin 6 production, possible in vivo anti-inflammatory effects of L. curvatus BYB3 were examined in the same mouse model. In addition, significantly lower levels of IL-6 and tumor necrosis factor receptor 1 upregulation were seen in the DSS+BYB3 group (compared to that in the DSS group). These results indicate that L. curvatus BYB3 exhibits health-promoting effects via immune modulation; and therefore, it can be used to treat various inflammatory diseases.

Deformation Behavior of Haynes230 Superalloy during Backward Flow Forming

Xing-kun Wang,Qinxiang Xia,Xiu-quan Cheng 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.1

Flow forming manufacturing technique has a unique advantage in producing thin-walled cylindrical parts, witnessing a growing demand in defense, aerospace and other fields. However, some of mechanisms of flow forming have not been deeply understood yet. Aiming at easily appearing problems of the crack and expanding, a finite element model with implicit code has been developed to simulate backward flow forming process for production of thin-walled superalloy tubular parts. The material displacement and stressstrain field distribution were obtained, impact of material displacement to dimensional accuracy and residual stress of spun part was analyzed; distribution of strain vector along thickness of spun part and its influence on the occurrence of fracture was analyzed. The results indicate that inhomogeneous distribution of material displacement in thickness brings about residual tensile stress in outer layer and residual compressive stress in inner layer of spun part; plastic deformation occurs mainly in the outer layer; shear plastic strain on the outer surface is much larger than the inner, which may lead to fracture on the outer surface. Above research can play an active role in understanding the mechanism of backward flow forming and deepening the understanding of fracture and the optimization of the process parameters.

Metabolites of Latilactobacillus curvatus BYB3 and Indole Activate Aryl Hydrocarbon Receptor to Attenuate Lipopolysaccharide-Induced Intestinal Barrier Dysfunction

Wang, Xing,Yong, Cheng Chung,Oh, Sejong Korean Society for Food Science of Animal Resource 2022 한국축산식품학회지 Vol.42 No.6

This study aimed to investigate the effects of the metabolites of Latilactobacillus curvatus BYB3 and indole-activated aryl hydrocarbon receptor (AhR) to increase the tight junction (TJ) proteins in an in vitro model of intestinal inflammation. In a Western blot assay, the metabolites of L. curvatus BYB3 reduced the TJ demage in lipoploysaccharide (LPS) stimulated-Caco-2 cells. This reduction was a result of upregulating the expression of TJ-associated proteins and suppressing the nuclear factor-κB signaling. Immunofluorescence images consistently revealed that LPS disrupted and reduced the expression of TJ proteins, while the metabolites of L. curvatus BYB3 and indole reversed these alterations. The protective effects of L. curvatus BYB3 were observed on the intestinal barrier function when measuring transepithelial electrical resistance. Using high-performance liquid chromatography analysis the metabolites, the indole-3-latic acid and indole-3-acetamide concentrations were found to be 1.73±0.27 mg/L and 0.51±0.39 mg/L, respectively. These findings indicate that the metabolites of L. curvatus BYB3 have increasing mRNA expressions of cytochrome P450 1A1 (CYP1A1) and AhR, and may thus be applicable for therapy of various inflammatory gut diseases as postbiotics.

Mg-doped ZnO layer to enhance electron transporting for PbS quantum dot solar cells

Xing Meibo,Wei Yuyao,Wang Dandan,Shen Qing,Wang Ruixiang 한국물리학회 2021 Current Applied Physics Vol.21 No.-

In this work, the effect of Mg doping on the performance of PbS quantum dot (QD) solar cells (QDSCs) is investigated. To elucidate that, PbS QDSCs with pristine ZnO and Mg-doped ZnO (ZMO) as electron transporting layers (ETLs) are fabricated, respectively. The current density-voltage (J-V) measurements are performed. The results show that the cell efficiency of the device with ZMO as an ETL is 9.46%, which increases about 75% compared to that of the pristine ZnO based device (5.41%). Enhanced short current density (Jsc) and fill factor (FF) are observed. It is demonstrated that Mg doping could passivate the surface defects and suppress the carrier recombination in ZnO ETL, thus resulting in larger bandgap and higher Fermi level (EF). The strategy of Mgdoped ZnO ETL provides a promising way for pushing solar cell performance to a high level.