The first application of modified neutron source multiplication method in subcriticality monitoring based on Monte Carlo

Wang, Wencong,Liu, Caixue,Huang, Liyuan Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.3

The control rod drive mechanism needs to be debugged after reactor fresh fuel loading. It is of great importance to monitor the subcriticality of this process accurately. A modified method was applied to the subcriticality monitoring process, in which only a single control rod cluster was fully withdrawn from the core. In order to correct the error in the results obtained by Neutron Source Multiplication Method, which is based on one point reactor model, Monte Carlo neutron transport code was employed to calculate the fission neutron distribution, the iterated fission probability and the neutron flux in the neutron detector. This article analyzed the effect of a coarse mesh and a fine mesh to tally fission neutron distributions, the iterated fission probability distributions and to calculate correction factors. The subcriticality before and after modification is compared with the subcriticality calculated by MCNP code. The modified results turn out to be closer to calculation. It's feasible to implement the modified NSM method in large local reactivity addition process using Monte Carlo code based on 3D model.

Stochastic Energy Scheduling in Microgrids With Intermittent Renewable Energy Resources

Wencong Su,Jianhui Wang,Jaehyung Roh IEEE 2014 IEEE transactions on smart grid Vol.5 No.4

<P>Renewable energy resources such as wind and solar are an important component of a microgrid. However, the inherent intermittency and variability of such resources complicates microgrid operations. Meanwhile, more controllable loads (e.g., plug-in electric vehicles), distributed generators (e.g., micro gas turbines and diesel generators), and distributed energy storage devices (e.g., battery banks) are being integrated into the microgrid operation. To address the operational challenges associated with these technologies and energy resources, this paper formulates a stochastic problem for microgrid energy scheduling. The proposed problem formulation minimizes the expected operational cost of the microgrid and power losses while accommodating the intermittent nature of renewable energy resources. Case studies are performed on a modified IEEE 37-bus test feeder. The simulation results demonstrate the effectiveness and accuracy of the proposed stochastic microgrid energy scheduling model.</P>

A Hybrid Life-Cycle Analysis and Two-Stage Stochastic Programming Model for Low-Carbon Management upon Urban Water Resources

Wencong Yue,Yanpeng Cai,Linyu Xu,Xumei Wang,Qiangqiang Rong,Lin Liu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

Due to population growth and economic development, water demands for municipal, industrial, and agricultural users are increasing. It is a challenging and critical issue in water resources system to properly allocate and utilize water resources to satisfy the goals of different stakeholders and greenhouse gases mitigation. In this study, a hybrid life-cycle analysis and two-stage stochastic programming model was proposed to analyze the water-allocation strategies based on complicated urban water resource system. The hybrid model can effectively assess the low-carbon performance of an urban water resources system in the framework of life-cycle analysis. The environmental impacts and GHGs reduction of urban water resources were firstly considered as the objective and constraint for solving the water allocation problems. The results indicated that the first-stage solutions of surface water conveyance of Dalian could be [3.83×108, 8.25×108] in 2015, and [3.83×108, 9.21×108] in 2020; Meanwhile, the first-stage solutions of surface water conveyance of Dalian could be [4.26×108, 8.68×108] in 2015, and [5.35×108, 10.7×108] in 2020.

Extraordinary Bending Formability of Mg–2.5Nd–0.5Zn–0.5Zr Alloy Sheet Through Pulsed Current

Wencong Zhang,Songhui Wang,Jinqi Pan,Jianlei Yang 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.11

The pulsed current effect on the bending formability and microstructure evolution of the Mg–2.5Nd–0.5Zn–0.5Zr (wt%)alloy sheet was systematically studied at near room temperature (20 ~ 45 ℃). The results showed that the bending ability ofthe alloy could be significantly improved by the pulsed current. Specifically, compared with the non-electrically-assistedbending, the limiting bending depth (from 5.05 to 14.82 mm) and limiting bending angle(from 57 to 145°) of the alloy wereincreased by 193.5% and 154.3%, respectively, and the bending yield strength (from 252 to 162 MPa) decreased by 35.7%. When the peak current density was 12.1 A/mm2 (EA12), the limiting bending angle reached 145°, and there was no crackon the outer surface of the bending sample. The main reason was that the pulsed current promoted the dislocation movement,which was conducive to the activation of basal slip and non-basal slip to maintain deformation compatibility. Thedeformation mechanism of electrically-assisted bending samples showed that {10–12} twin dominated in the compressionzone, while basal slip dominated in the tension zone. In addition, the effects of peak current density on microstructure,texture evolution and fracture mechanism were analyzed in detail. It provided important theoretical guidance for masteringthe bending-forming mechanism of rare-earth magnesium alloys.

Effect of Tension Temperature on the Anisotropy of Tensile Behavior for Az31 Alloys: A Visco-Plastic Self-Consistent Analysis

Wenke Wang,Jaimyun Jung,Chao Cui,Wenzhen Chen,Yang Yu,Peng Li,Wencong Zhang,Renlong Xiong,김형섭 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.4

In this work, the anisotropy variation of tensile flow stress for AZ31 magnesium alloys was investigated at various temperaturesand tensile strains with the help of the visco-plastic self-consistent model. The results showed that the anisotropyof flow stress was weakened with the increase of tensile temperature, while such anisotropy presented a slightly increasingstage first and then a continuously decreasing stage with the increase of tensile strain. During the tension deformation, theactivations of basal slip and tension twinning, together contributed to the development of a (0002)//LD (LD: loading direction)type texture. In contrast, the activations of prismatic slip produced a ⟨10–10⟩//LD type texture. Such texture variationsinfluenced the Taylor factors, but did not cause significant differences in the flow stress. By comparison, the difference inthe macroscopic average resolved shear stress, which was calculated according to the critical resolved shear stress of eachdeformation mode and their respective activation fractions, decreased significantly with the increase of tensile temperatureor tensile strain. This was the major reason for the decline of the tension deformation behavior anisotropy.

Achieving Ultra-High-Strength and Good Ductility of the ZK60 Alloy Sheet by High Strain-Rate Rolling

Songhui Wang,Wencong Zhang,Jianlei Yang,Xeuyan Jiao,Jinqi Pan,Guannan Chu,Xiangyu Dai 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.4

A superior combination of the ultra-high tensile strength (~ 419.9 MPa), the yield strength (~ 376.9 MPa) and the elongation(~ 14.8%) ZK60 sheet was successfully achieved by high-strain rate rolling. The ultrahigh strength was attributed to theuniform ultrafine-grained structure. The excellent ductility was ascribed to the ultrafine grains, low dislocation density andweakened basal texture in the final structure.

Eco-friendly and Durable Antibacterial Cotton Fabrics Prepared with Polysulfopropylbetaine

Li Zhou,Hongbo Wang,Jinmei Du,Jiajia Fu,Wencong Wang 한국섬유공학회 2018 Fibers and polymers Vol.19 No.6

A novel antibacterial agent polysulfopropylbetaine (PSPB) bearing carboxyl groups was synthesized and its application on cotton fabric to provide durable antibacterial property was also presented. The successful synthesis of PSPB and its immobilization onto the cotton fabric surface were verified by a series of tests including FTIR, 1H NMR, XPS and SEM. Viable cell counting method was employed to investigate antibacterial properties of the finished cotton fabrics. It was found that the cotton fabrics treated with PSPB were endowed with desirable antibacterial activity against both gram-negative bacteria Esherichia coli (E.coli, AATCC 6538) and gram-positive bacteria Staphylococcus aureus (S.aureus, AATCC 25922), with the bacterisotatic rates of 99.69 % and 99.95 %, respectively. Notably, the bacterial reduction rates still maintained over 90 % against both bacteria even after 50 consecutive laundering cycles. Moreover, tests concerning the hydrophilicity, air permeability, water vapor transmission, mechanical properties as well as thermal properties were carried out systematically. The experimental results indicated the hydrophilic performance, air permeability and moisture penetrability of the cotton fabrics finished with PSPB were improved greatly in spite of a slight reduction in thermal performance and little obvious influence on mechanical performance. The antibacterial cotton fabric has the potential to be applied in sportswear, underwear, household textiles, medical fields and much more.