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.

20대 중국 여성 소비자들의 라이프스타일 유형과 명품 구매 행동에 관한 연구

Wang XinGe,박성연,Luo Hong 한국국제경영학회 2020 國際經營硏究 Vol.31 No.1

중국 소비자들의 소비영향력이 커지고 있음에도 불구하고 라이프스타일과 명품소비에 관한 연구는 매우 부족 한 실정이다. 본 논문은 중국의 소비 주체인 여성 소비자 중에서 특히 명품소비의 새로운 계층으로 등장한 20대 젊은 여성 소비자 321명에 대해 설문조사를 실시하였으며 그들의 라이프스타일을 분석하고 명품소비행동을 연구하였다. 연구 결과에 따르면 20대 중국 여성 소비자들의 라이프스타일(의생활, 식생활, 주생활, 소비생활, 여가생활, 가치관)을 분류한 결과 전통적 보수형, 계획적 성공추구형, 비계획적 소비추구형 3가지 라이프스타일로 분류되었다. 전통적 보수형은 소득수준이 낮고 모든 요인들에 있어서 보수적이고 소극적 태도를 보였며, 계획적 성공추구형은 여성의 사회진출 증가로 인해 사회적 성공을 추구하면서 계획적으로 생활하는 집단이며, 비계획적 소비추구형은 쇼핑을 즐기며 지출을 많이 하는 특성을 보여주었다. 구입한 명품 브랜드의 종류, 연간 명품 구매 수량, 연간 명품 구매 금액 및 명품 구매 이유는 통계적으로 유의한 차이가 있었으나 명품 품목, 명품 구매 장소와 정보원은 유의한 차이가 없었다. 최근 중고명품 시장이 크게 증가하고 있어 새 명품과 중고 명품에 대한 태도와 행동을 비 교한 결과 새 명품의 구매의도와 추천의도가 중고 명품에 비해 더 높은 것으로 나타났다. 본 논문은 중국 소비자들에 대한 체계적 연구의 틀과 방법 및 유용한 자료를 제공함으로써 중국 소비자 행동 연구와 라이프스타일 연구, 명품 소비 연구의 학문적 발전에 기여할 수 있는 것으로 기대된다. 또한 명품 브랜 드들이 20대 중국 여성들을 위한 마케팅 전략을 수립하는 데 있어 실무적인 시사점도 제공할 수 있는 것으로 기대된다. China, as the global center of luxury consumption, is receiving increasing attention although there has been a contraction in the global economy and in consumer sentiment in recent years. However, there is a lack of research on Chinese consumers’ lifestyle which can effectively explain their psychology and behavior as well as significantly impact on their luxury consumption desire and purchase intention. The purpose of this research is not only to classify the lifestyle of Chinese consumers but also to investigate its relationship to luxury consumption. This paper analyzed questionnaire survey of 321 Chinese consumers in their 20s and classified their lifestyles by the dimensions of clothing, eating, living, consuming and leisure life, and values. The results show that three lifestyle clusters were found: traditional conservative, planned pursuit of success, and unplanned consumption oriented. With respect to luxury-buying behaviors, there are significant differences among the three lifestyles regarding the purchased major brands, the amount and expense of luxury purchases, and the reasons for the purchase behaviors. Insignificant differences were found in the types of luxuries, the main purchase locations, or information sources. There was a far greater tendency to buy and recommend new luxury items than second-hand luxuries in all three lifestyles. This empirical study offers new framework and method for systematic research on Chinese consumers. It is expected that this study will provide academic contribution to researches on Chinese consumer behavior, lifestyle, and luxury consumption. In addition, it is expected to provide practical marketing implications for the luxury brands targeting Chinese women in their 20s.

Improving Cellulase Production in Trichoderma koningii Through RNA Interference on ace1 Gene Expression

( Wang Shao Wen ),( Miao Xing ),( Gang Liu ),( Shao Wen Yu ),( Juan Wang ),( Sheng Li Tian ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.8

Ribonucleic acid interference (RNAi) inhibits the expression of target genes in a sequence-specific manner, and shows potential for gene knockdown in filamentous fungi, in which the locus-specific gene knockout occurs in low frequency. In this study, the function of the repressor of cellulase expression I (ACEI) was verified in Trichoderma koningii (T. koningii) YC01 through RNAi, and ace1-silenced strains with improved cellulase productivity were obtained. An expression cassette that transcribed the interfering double-stranded RNA (dsRNA) of ace1 was constructed and transformed into T. koningii, and the transformants, in which the expression of ace1 was successfully silenced, were selected. As a result of the ace1 gene silencing, the expression levels of the main cellulase and xylanase genes were elevated, and the enhanced production of total proteins, cellulase, and xylanase was observed in the cultivation. In addition, the downregulation of ace1 resulted in an increasing expression of xyr1, but no clear variation in the expression of cre1, which suggested that ACEI acted as a repressor of the xyr1 transcription, but was not involved in the regulation of the cre1 expression. The results of this work indicate that ace1 is a valid target gene for enhancing enzyme production in T. koningii, and RNAi is an appropriate tool for improving the properties of industrial fungi.

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.

Surface Molecularly Imprinted Polymers Based on NH2-MIL-53 for Selective Extraction Ochratoxin A in Real Sample

Xing Zhang,Juan He,Huige Wang,Pengfei Xu,Mingyu Wang,Yuanyuan Li,Jing Chen,Lijun He 한국고분자학회 2022 Macromolecular Research Vol.30 No.10

In this study, surface molecularly imprinted polymers were synthesized with the metal-organic framework NH2-MIL-53 as carrier and naringenin as alternative template of Ochratoxin A (OTA). The amino groups on the surface of NH2-MIL- 53 reacted with the epoxy groups in glycidyl methacrylate (GMA). Subsequently, the double bonds of the GMA grafting on the surface of the material were used for polymerization to prepare the surface molecularly imprinted polymers. The obtained polymers were characterized by scanning electron microscope, transmission electron microscope, energy spectrometer, Fourier infrared spectrometer, X-ray diffraction, and laser particle size analyzer. Synthetic polymer was combined with solid phase extraction for separation and enrichment of trace OTA in grains. The spiked recoveries were found to be 78.95-106.45%, with relative standard deviations ranging from 5.16% to 6.31%. The detection limit and the quantification limit of the method were 0.04 μg·kg-1 and 0.12 μg·kg-1, respectively. Comparing the pretreatment effects of the self-made cartridge and the immunoaffinity column on the OTA in the sample, it showed that the self-made column had excellent performance and provided a new pretreatment method for the treatment of OTA in grains.

Retrospective Study of Gemcitabine Based Chemotherapy for Unresectable or Recurrent Esophagus Squamous Cell Carcinoma Refractory to First Line Chemotherapy

Wang, Mei,Gu, Jun,Wang, Hai-Xing,Wu, Mei-Hong,Li, Yong-Mei,Wang, Ya-Jie Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Purpose: To investigate the efficacy and toxicity of a combination of gemcitabine with nedaplatin (GN) or cisplatin (GC) for patients with unresectable or recurrent esophagus squamous cell carcinoma. Methods: Gemcitabine was administered at 1 g/m2 intravenously on days 1 and 8; and nedaplatin or cisplatin were administered at 80 mg/m2 intravenously on day 1. We analyzed the response rate, overall survival time, progression-free survival time, and toxicity in 21 patients treated with GN and 27 patients treated with GC. Results: In patients treated with gemcitabine plus nedaplatin, the ORR was 47.6%, the median progression-free survival time was 4.1 months, and the median survival time was 9.3 months. In patients treated with gemcitabine plus cisplatin, the ORR was 48.2%, the median progression-free survival time was 3.9 months, and the median survival time was 9.1 months, respectively. There were no statistically significant differences in ORR, PFS and OS between the two groups. In both, the most commonly observed toxicities were thrombocytopenia and fatigue. Nausea and vomiting was more frequent in the GC group than in the GN group. Conclusion: Gemcitabine based chemotherapy was effective and tolerable for patients with unresectable or recurrent esophagus squamous cell carcinoma refractory to first line chemotherapy.