• 제목/요약/키워드: LU7

검색결과 442건 처리시간 0.022초

Simplification analysis of suction pile using two dimensions finite element modeling

  • Hendriyawan, Hendriyawan;Primananda, M. Abby;Puspita, Anisa Dwi;Guo, Chao;Hamdhan, Indra Noer;Tahir, M.M.;Pham, Binh Thai;Mu'azu, M.A.;Khorami, Majid
    • Geomechanics and Engineering
    • /
    • 제17권4호
    • /
    • pp.317-322
    • /
    • 2019
  • This paper presents the results of parametric analyses to compute the axial capacity of a suction pile using 2D and 3D finite element approaches. The study is intended to simplify the process of analyzing suction piles from 3D to 2D model. The research focuses on obtaining the coefficient to be applied into the 2D model in order to obtain results that are as close as possible to the 3D model. Two 2D models were used in the analysis, namely the plane strain and axisymmetric models. The analyses were performed using two actual offshore soil data of the North and West Java Indonesia. The study reveals that the simplification of model through 2D Finite Element is achievable by applying the appropriate coefficient to the stiffness parameters. The results show that the simplified model of the 2D FEA provides more conservative results (with the difference between 2% to 7%) than the 3D FEA.

Study on bidirectional fluid-solid coupling characteristics of reactor coolant pump under steady-state condition

  • Wang, Xiuli;Lu, Yonggang;Zhu, Rongsheng;Fu, Qiang;Yu, Haoqian;Chen, Yiming
    • Nuclear Engineering and Technology
    • /
    • 제51권7호
    • /
    • pp.1842-1852
    • /
    • 2019
  • The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steadystate and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

Development and validation of reactor nuclear design code CORCA-3D

  • An, Ping;Ma, Yongqiang;Xiao, Peng;Guo, Fengchen;Lu, Wei;Chai, Xiaoming
    • Nuclear Engineering and Technology
    • /
    • 제51권7호
    • /
    • pp.1721-1728
    • /
    • 2019
  • The advanced node core code CORCA-3D is one of the independent developed codes of NPIC for the nuclear reactor core design. CORCA-3D code can calculate the few-group cross section, solve the 3D diffusion equations, consider the thermal-hydraulic feedback, reconstruct the pin-by-pin power. It has lots of functions such as changing core status calculation, critical searching, control rod value calculation, coefficient calculation and so on. The main theory and functions of CORCA-3D code are introduced and validated with a lot of reactor measured data and the SCIENCE system. Now, CORCA-3D code has been applied in ACP type reactor nuclear cores design.

Development and verification of PWR core transient coupling calculation software

  • Li, Zhigang;An, Ping;Zhao, Wenbo;Liu, Wei;He, Tao;Lu, Wei;Li, Qing
    • Nuclear Engineering and Technology
    • /
    • 제53권11호
    • /
    • pp.3653-3664
    • /
    • 2021
  • In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO2 benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is -5.08% in the rod ejection condition and while -5.09% in the control rod complex movement condition.

Effects of dietary Enteromorpha powder on reproduction-related hormones and genes during the late laying period of Zi geese

  • Ma, Wei Qing;Zhao, Dan Hua;Cheng, Huang Zuo;Wang, Si Bo;Yang, Ji;Cui, Hong Xia;Lu, Ming Yuan;Wu, Hong Zhi;Xu, Li;Liu, Guo Jun
    • Animal Bioscience
    • /
    • 제34권3_spc호
    • /
    • pp.457-462
    • /
    • 2021
  • Objective: The aim of this study was to investigate the effects of Enteromorpha powder supplementation on reproduction-related hormones and genes in the late laying period of Zi geese. Methods: A total of 312 (1-year-old) Zi geese with similar laying rate were randomly divided into 2 groups with 6 replicates each, each with 21 female geese and 5 male geese. The control group was fed with a basal diet and the test group was fed with a diet containing 3% Enteromorpha powder. The trial period lasted for 7 weeks. Results: Our results showed that the laying rate was improved in the test group at each week of trial (p<0.01), and the levels of estradiol in serum and prolactin in ovary were increased compared with the control group (p<0.05). Conclusion: Based on above results, Enteromorpha powder supplementation at 3% could promote reproductive performance during the late laying period of Zi geese.

Foreign Capital Flows, Banking Stability and the Role of International Trade Cooperation and Distribution an Empirical Analysis from the ASEAN Region

  • LU, Chi Huu;LUONG, Thuy Thi Thu
    • 유통과학연구
    • /
    • 제20권7호
    • /
    • pp.23-33
    • /
    • 2022
  • Purpose: Although foreign capital flows have played a vital role in fostering the economic growth in recipient countries, there are some concerns about the adverse impact of international capital flows on the banking stability. Hence, the study revisits this issue to explore the relationship between the different types of foreign investments and banking stability in ASEAN region. Research design, data and methodology: Based on the bank-level data of 96 commercial banks and country-level in six ASEAN countries from 2008 to 2019, we perform the multivariate regression analysis and provide a variety of robustness tests. Results: Our empirical evidence shows the volatility of foreign portfolio investments has significantly negative effect on the banking stability, besides that of foreign other investments has the similar influence but the result is relatively less pronounced in some robustness tests. Additionally, increasing trade cooperation and international distribution may lead countries to face higher risk of banking instability driven from these international investments. Meanwhile, the impact of foreign direct investments is positive, but the evidence is the least obvious. Conclusions: Our findings suggest policy-makers in ASEAN and emerging nations as a whole should carefully consider when building policies-related to mitigate the adverse impact of foreign capital flows.

Scalable Blockchain Storage Model Based on DHT and IPFS

  • Chen, Lu;Zhang, Xin;Sun, Zhixin
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권7호
    • /
    • pp.2286-2304
    • /
    • 2022
  • Blockchain is a distributed ledger that combines technologies such as cryptography, consensus mechanism, peer-to-peer transmission, and time stamping. The rapid development of blockchain has attracted attention from all walks of life, but storage scalability issues have hindered the application of blockchain. In this paper, a scalable blockchain storage model based on Distributed Hash Table (DHT) and the InterPlanetary File System (IPFS) was proposed. This paper introduces the current research status of the scalable blockchain storage model, as well as the basic principles of DHT and the InterPlanetary File System. The model construction and workflow are explained in detail. At the same time, the DHT network construction mechanism, block heat identification mechanism, new node initialization mechanism, and block data read and write mechanism in the model are described in detail. Experimental results show that this model can reduce the storage burden of nodes, and at the same time, the blockchain network can accommodate more local blocks under the same block height.

Three-dimensional numerical parametric study of tunneling effects on existing pipelines

  • Shi, Jiangwei;Wang, Jinpu;Ji, Xiaojia;Liu, Huaqiang;Lu, Hu
    • Geomechanics and Engineering
    • /
    • 제30권4호
    • /
    • pp.383-392
    • /
    • 2022
  • Although pipelines are composed of segmental tubes commonly connected by rubber gasket or push-in joints, current studies mainly simplified pipelines as continuous structures. Effects of joints on three-dimensional deformation mechanisms of existing pipelines due to tunnel excavation are not fully understood. By conducting three-dimensional numerical analyses, effects of pipeline burial depth, tunnel burial depth, volume loss, pipeline stiffness and joint stiffness on bending strain and joint rotation of existing pipelines are explored. By increasing pipeline burial depth or decreasing tunnel cover depth, tunneling-induced pipeline deformations are substantially increased. As tunnel volume loss varies from 0.5% to 3%, the maximum bending strains and joint rotation angles of discontinuous pipelines increase by 1.08 and 9.20 times, respectively. By increasing flexural stiffness of pipe segment, a dramatic increase in the maximum joint rotation angles is observed in discontinuous pipelines. Thus, the safety of existing discontinuous pipelines due to tunnel excavation is controlled by joint rotation rather than bending strain. By increasing joint stiffness ratio from 0.0 (i.e., completely flexible joints) to 1.0 (i.e., continuous pipelines), tunneling-induced maximum pipeline settlements decrease by 22.8%-34.7%. If a jointed pipeline is simplified as a continuous structure, tunneling-induced settlement is thus underestimated, but bending strain is grossly overestimated. Thus, joints should be directly simulated in the analysis of tunnel-soil-pipeline interaction.

Acupuncture for Adult Obstructive Sleep Apnea or Obstructive Sleep Apnea-Hypopnea Syndrome: A Review of the China National Knowledge Infrastructure Database

  • Hye Kyung, Baek;Young Jun, Kim;Yeon Sun, Lee;Hye Ri, Jo;Mi So, Park;Dong Guk, Shin;Hyun A, Shim
    • Journal of Acupuncture Research
    • /
    • 제39권4호
    • /
    • pp.275-282
    • /
    • 2022
  • The purpose of this study was to analyze acupuncture treatment methods and acupoints used to treat obstructive sleep apnea (OSA) or obstructive sleep apnea-hypoapnea syndrome (OSAHS). The data were retrieved from January 2010 to May 2022 from the China National Knowledge Infrastructure database. The search terms included "adult," "obstructive sleep apnea," "obstructive sleep apnea hypoapnea syndrome," "acupuncture," and "electro-acupuncture." Clinical trials for acupuncture treatment of OSA or OSAHS were included in this review (4 non-randomized controlled studies, 1 was a case report, and 10 randomized controlled studies). For OSA and OSAHS treatment, the acupoints that were most frequently used included REN23, LU7, ST40, EX9, LI11, and DU20. Compared with the control or Western treatment group, the treatment outcome measures of participants in the acupuncture treatment group significantly improved. In some studies, participants in the acupuncture group did not have side effects and the treatment was cost-effective. The data analyzed in this review suggest that acupuncture is an effective treatment for OSA or OSAHS.

Social Distance of Affective Advice: The Role of Construal Level in Acceptance of Rational and Emotional Advice

  • Li, Lu
    • 예술인문사회 융합 멀티미디어 논문지
    • /
    • 제7권4호
    • /
    • pp.395-402
    • /
    • 2017
  • Social network service provides an excellent platform for people seeking for advices. This research analyzed the effect of rational and emotional response and social distance on people's acceptance for advices online by the construal level theory. An experiment was completed to test the relationship between advisers and questioners and verify the content of online feedback would influence people's acceptance for advices on social network site. The online response included emotional advice and rational advice. Social distance between advisers and questioners was divided to close social distance condition and distant social distance condition. The study showed: (1) comparing with emotional advice, rational advice had a higher persuasive effect in both close and distant social distance conditions; (2) the impact of feedback from people with close social distance was stronger than the impact of the advices from people with distant social distance; (3) there existed an interaction effect between social distance and affective advice. The results revealed that the adviser's affective expression and relationship with the questioner would interactively impact the online persuasive effect.