Application of the French Codes to the Pressurized Thermal Shocks Assessment

Mingya Chen,Guian Qian,Jinhua Shi,Rongshan Wang,Weiwei Yu,Feng Lu,Guodong Zhang,Fei Xue,Zhilin Chen 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.6

The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs)has been extensively studied. This paper introduces an integrity assessment of an RPVsubjected to a PTS transient based on the French codes. In the USA, the “screening criterion”for maximum allowable embrittlement of RPV material is developed based on theprobabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, whichare developed based on the deterministic fracture mechanics, there is no “screening criterion”. In this paper, the methodology in the RCC-M and RSE-M codes, which are used forPTS analysis, are firstly discussed. The bases of the French codes are compared with ASMEand FAVOR codes. A case study is also presented. The results show that the method in theRCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF)may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significantdifferences in the assessment results. Therefore, homogenization of the codes inthe long time operation of nuclear power plants is needed.

Multi-objectives topology optimization of frame in an electric mining dump truck based on fuzzy satisfaction variable weight coefficients method

Jinhua Liu,Liang Luo,Xuewen Xiao,Chen Zhang,Ling Zhang,Chengji Mi 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

In order to optimize the stiffness and strength and modal characteristics of frame in an electric mining dump truck determined by experiential design, the multi-objectives topology optimization is the most frequently used method. However, each single objective satisfaction degree has fuzziness when it comes to solve engineering problems. In this paper, a novel fuzzy multi-objective topology optimization method based on fuzzy satisfaction variable weight coefficients was presented. Based on the variable density method and SIMP interpolation model, the single objective topology optimization design under different conditions was performed. The fuzzy membership function was utilized to measure the sub-objective fuzzy satisfaction degree of frame. The weight factor of each single objective was dynamically assigned through variable weight approach. In consideration of fatigue stress constraint, the fuzzy multi-objectives topology optimization of frame was conducted through OptiStruct solver. The results showed that the stiffness of optimized frame under forward torsion and post torsion and full torsion conditions was improved by 4.7 %, 7.4 % and 5.4 %, respectively, while the stiffness of optimized frame under bending condition was worsened by 2.7 %. The first order natural frequency of optimized frame was improved by 5.6 %.

The Construction of the Heterostructural Bi2O3/g-C3N4 Composites with an Enhanced Photocatalytic Activity

Jinhua Zhang,Huiyue Qian,Wencheng Liu,Hao Chen,Yang Qu,Zhidong Lin 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.6

A heterostructural composite composed of g-C3N4 and Bi2O3 was achieved by the one-pot and thermal-induced polycondensation method using melamine and Bi(NO3)3 as precursor at 550 ℃ under air atmosphere. The crystalline phase, components and morphologies of the as-prepared composites were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Besides, the photocatalytic activity of composites was evaluated by degrading RhB aqueous solution at room temperature under visible light irradiation. Compared with bulk g-C3N4, the photocatalytic efficiency of the 0.5% Bi2O3/g-C3N4 (Bi–CN) was increased by up to four times. The introduction of Bi2O3 enhances not only the light absorption ability, but also the separation of photogenerated electron–hole pairs.

Impact of Intersecting Angles on Evacuation Efficiency of Pedestrian Flows in High Volume: A Case Study in Metro Station

Manman Chen,Jinghong Wang,Youran Zhi,Jinhua Sun 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

The intersection of pedestrian flows is a general phenomenon in daily pedestrian traffic and emergency evacuation. However, lacking of effective controls in crowed areas will result in pedestrian deceleration, stopping, and even threats to safety in evacuation. This paper focused on exploring the influence of different intersecting angles on evacuation efficiency of pedestrian flows in high volume. Through establishing a bidirectional pedestrian flow model with different intersecting angles for a busy metro station in China based on the social force model, two factors, namely the impact between pedestrians and the conflict frequency, were firstly proposed and validated as that playing major roles in influencing the evacuation efficiency during the pedestrian intersection. With the case study, it is found that the best intersecting angle is 120 degree and angles between 40 and 80 degree are unfavorable in optimizing the average crowd speed and the crowd density. The results are verified based on the comparative analysis with some existing experimental results. The outcomes of this work can offer some guidelines to control the intersection of pedestrian flows during evacuation and can make contributions to a proposal for the related, optimized design of a structure to increasing the evacuation efficiency of a dense crowd.

The effect of environmental innovation behavior on economic and environmental performance of 182 Chinese firms

Long, Xingle,Chen, Yaqiong,Du, Jianguo,Oh, Keunyeob,Han, Insoo,Yan, Jinhua Elsevier 2017 JOURNAL OF CLEANER PRODUCTION Vol.166 No.-

<P><B>Abstract</B></P> <P>This paper investigated the role of environmental innovation behavior in the economic and environmental performance of 182 Chinese firms. We established an extended theory of planned behavior (TPB) model and proposed seven hypotheses by combining TPB and environmental innovation theory. Through structure equation model, we found that attitude toward environment behavior, subjective environmental norm, perceived environment behavioral control positively impact environmental innovation intention. Environmental innovation behavior had a 0.232 larger effect on environmental performance than on economic performance. Production processes have a 0.028 greater positive influence on environmental performance than on economic performance. Enhancing environmental innovation promotes sustainable development. It is important to strengthen cleaner production processes to reduce environmental pollution. It is a significant obligation to conduct environment-related education or training for personnel within firms.</P>

The effect of environmental innovation behavior on economic and environmental performance of 182 Chinese firms

LONG Xingle,CHEN Yaqiong,DU Jianguo,OH Keunyeob,HAN Insoo,YAN Jinhua 한국무역학회 2017 한국무역학회 국제학술대회 Vol.2017 No.11

Effects of maternal dietary energy restriction on laying performance, embryonic development, and lipid metabolism in broilers

Sun, Hao,Chen, Zhihui,Ma, Chengzhan,Lian, Lina,Zhao, Zeyu,Niu, Shupeng,Xu, Liangmei,Sun, Jinhua Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: The objective of this study was to investigate the effects of different degrees of maternal dietary energy restriction on lipid deposition in embryonic tissues during the medium laying period (37 to 39 weeks) in Arbor Acres (AA) broiler breeders. Methods: A single factor design was adopted, and 400 AA broiler breeders (20 weeks of age) with a similar weight were randomly allocated into four groups. The birds in the control group were fed a corn-soybean meal based diet, and those in trial groups were fed diets with 80%, 70%, and 50% energy levels of the basal diet. Incubated eggs from the medium laying period were collected. Samples of developing embryos at various stages were prepared for composition analysis. Results: The embryo weight in the 80% energy group was higher than those of the other groups on embryonic day (E) 13, but at 21 E, they were significantly decreased with decreasing energy intake of the broiler breeders (p<0.05). Additionally, the levels of crude fat in tissues in the restriction groups were significantly decreased (p<0.05). The long axis and area of adipocytes in breast muscle, thigh muscle and the liver were significantly decreased (p<0.05) at 21 E in the 80%, 70%, and 50% energy groups. Conclusion: The effects of the 80% maternal dietary energy restriction energy affects egg production performance, egg quality, and nutrient deposition in egg weights, which then directly impacts on the developmental process of embryos, especially on fat utilization and deposition.

Quasi-static test of the precast-concrete pile foundation for railway bridge construction

Zhang, Xiyin,Chen, Xingchong,Wang, Yi,Ding, Mingbo,Lu, Jinhua,Ma, Huajun Techno-Press 2020 Advances in concrete construction Vol.10 No.1

Precast concrete elements in accelerated bridge construction (ABC) extends from superstructure to substructure, precast pile foundation has proven a benefit for regions with fragile ecological environment and adverse geological condition. There is still a lack of knowledge of the seismic behavior and performance of the precast pile foundation. In this study, a 1/8 scaled model of precast pile foundation with elevated cap is fabricated for quasi-static test. The failure mechanism and responses of the precast pile-soil interaction system are analyzed. It is shown that damage occurs primarily in precast pile-soil interaction system and the bridge pier keeps elastic state because of its relatively large cross-section designed for railways. The vulnerable part of the precast pile with elevated cap is located at the embedded section, but no plastic hinge forms along the pile depth under cyclic loading. Hysteretic curves show no significant strength degradation but obvious stiffness degradation throughout the loading process. The energy dissipation capacity of the precast pile-soil interaction system is discussed by using index of the equivalent viscous damping ratio. It can be found that the energy dissipation capacity decreases with the increase of loading displacement due to the unyielding pile reinforcements and potential pile uplift. It is expected to promote the use of precast pile foundation in accelerated bridge construction (ABC) of railways designed in seismic regions.

Green multi-functional monomer based ion imprinted polymers for selective removal of copper ions from aqueous solution

Wang, Liyan,Li, Jinhua,Wang, Jianan,Guo, Xiaotong,Wang, Xiaoyan,Choo, Jaebum,Chen, Lingxin Academic Press 2019 Journal of colloid and interface science Vol.541 No.-

<P><B>Abstract</B></P> <P>Green ion imprinted polymers (IIPs) were prepared in aqueous phase via the synergy of three functional monomers of low-cost eco-friendly gelatin (G), 8-hydroxyquinoline (HQ) and chitosan (C), namely G-HQ-C IIPs, and were applied as an effective and recyclable adsorbent to remove Cu(II) from aqueous solution. The as-prepared G-HQ-C IIPs were systematically characterized, and several major factors affecting adsorption capacity including solution pH, temperature and contact time were investigated in detail. The adsorption of Cu(II) on G-HQ-C IIPs followed the pseudo-second-order kinetic and Langmuir isotherm models, and the adsorption capacity increased with temperature increase. Moreover, the maximum adsorption capacities of G-HQ-C IIPs toward Cu(II) reached up to 111.81 mg/g at room temperature, much higher than those of most of the reported adsorbents for Cu(II). The G-HQ-C IIPs displayed excellent selectivity against seven common divalent ions with selectivity coefficients above 18.71, as well as high anti-interference ability. Additionally, a good reusability was demonstrated without significant loss in adsorption capacity after at least ten cycles. The IIPs were applied to environmental water samples for selective removal of Cu(II) with satisfactory results. By replacing Cu(II) template by Cd(II), Hg(II) and Pb(II), respectively, the obtained three kinds of IIPs based on G-HQ-C presented convincing imprinting properties, and therefore the work could provide a simple and general imprinting strategy toward various concerned heavy metal ions through multi-point interactions from multiple functional monomers.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effect of Y2O3 content on Ni60 alloy cladding layer

Fangping Yao,Zhi Ming,Jinhua LI,Xiang Chen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

Six kinds of Ni60 alloy coatings with different percentage of Y 2 O 3 were prepared by laser cladding. A metallurgical microscope was used to analyze the morphology of the cladding layer. Scanning electron microscopy and EDS energy spectrum analysis were used to characterize the microstructure and element segregation of the cladding layer. A Vickers microhardness tester was used to measure the hardness of the cladding layer. Finally, a friction and wear tester established the friction and wear properties of the cladding layer. The study results show that Y 2 O 3 can significantly reduce the height of the cladding layer and increase the width of the cladding layer; it can also improve the structure refinement and element segregation of the cladding layer. The microhardness of the cladding layer is significantly improved compared to the Ni60 alloy coating without Y 2 O 3 , thereby enhancing the wear resistance of the coating.