Modelling of effective irradiation swelling for inert matrix fuels

Zhang, Jing,Wang, Haoyu,Wei, Hongyang,Zhang, Jingyu,Tang, Changbing,Lu, Chuan,Huang, Chunlan,Ding, Shurong,Li, Yuanming Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.8

The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.

Multi-Objective Energy Absorption Capability Optimization of Braided Composite Tubes with Improved Trigger

Xu Zhang,Yuanming Xu,Shuming Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.4

With the increased use of composite materials in aircraft main load-bearing structures, it is of great significance tostudy the failure modes and energy absorption characteristics of the structures made up of composite materials. This paperused finite element method (FEM) and investigated the performances of braided composite tubes with semi-circular cavityexternal trigger during crashing. The generated data were used to modify the dynamic Kriging model. Based on the surrogatemodel, the artificial bee colony (ABC) optimization algorithm was used to optimize the cavity radius, tube diameter and tubethickness, so as to minimize the peak load and maximize the specific energy absorption (SEA). The results showed that theKriging model had high accuracy and efficiency in simulating the stress and deformation. The proposed model determinedthe optimized parameters using the ABC model, one of which improved the SEA by 39.6 % and reduced the peak load by38.6 %, thereby improving the structural properties of braided composite materials.

The Improvement of the Design Standard of Overloaded Highway

Dou Yuanming,Zhang Jingjing,Hu Chao 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

With the development of the transportation industry, the trend of overload is obviously, design load of highway bridges needs to be improved. Based on the field investigation and data analysis, this study modifies the design standers of highway. The regularities on characteristics of models, vehicle weight and the distribution of axle load and spacing were studied. Using the Matlab programming language and the Monte Carlo numerical simulation method to simulate a random traffic model, then loaded on simple bridges and continuous bridges with different span in order to calculate bending effect. The data were compared with the first level in highway load code and proposed the load increase parameters: when the span is less than 20 m, then use 1.2 times the standard specification in bridge design; in other situation, use 1.3 times the standard factor. Analyzing the characteristic of the vehicle load, can not only give technical parameters for the quantitative analysis of overloading traffic effects on the fatigue damage of bridge, but also provide a reference for bridge design units and the operation management department. So it has great realistic significance and research value.

ZnO@Ni–Co–S Core–Shell Nanorods-Decorated Carbon Fibers as Advanced Electrodes for High-Performance Supercapacitors

Yanwei Sui,Man Zhang,Haihua Hu,Yuanming Zhang,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yezeng He,Yaojian Ren,Zhi Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

The interconnected three-dimensional Ni–Co–S nanosheets were successfully deposited on ZnO nanorods by a one-step potentiostatic electrodeposition. The Ni–Co–S nanosheets provide a large electrode/electrolyte interfacial area which has adequate electroactive sites for redox reactions. Electrochemical characterization of the ZnO@Ni–Co–S core–shell nanorods presents high specifc capacitance (1302.5 F/g and 1085 F/g at a current density of 1 A/g and 20 A/g), excellent rate capabilities (83.3% retention at 20 A/g) and great cycling stability (65% retention after 5000 cycles at a current density of 30 A/g). The outstanding electrochemical performance of the as-prepared electrode material also can be ascribed to these reasons that the special structure improved electrical conductivity and allowed the fast diffusion of electrolyte ions.

Laparoscopic radical cystectomy with pelvic lymph node dissection and ileal orthotopic neobladder by a total extraperitoneal approach: Our initial technique and short-term outcomes

Guanqun Zhu,Zongliang Zhang,Kai Zhao,Xinbao Yin,Yulian Zhang,Zhenlin Wang,Chen Li,Yuanming Sui,Xueyu Li,Han Yang,Nianzeng Xing,Ke Wang 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.5

Purpose: With the increasing application of laparoscopic or robot-assisted radical cystectomy, a reliable and promising method is needed for reducing postoperative complications. We describe the short-term outcomes of totally extraperitoneal laparoscopic radical cystectomy (TELRC) with extraperitoneal pelvic lymph node dissection (EPLND) and extraperitoneal ileal orthotopic neobladder (EION) techniques. Materials and Methods: From January 2020 to December 2021, we performed TELRC and EPLND with EION in 72 patients in our center. The accompanying video highlights our novel techniques. The patients’ demographic data, intraoperative data, and perioperative complications were collected, and short-term oncological and functional results are reported. Results: All procedures were technically successful without conversion to open surgery. The patients’ mean body mass index was 26.22±5.71. Median age was 57.51±12.34 years. Average hospital stay was 13.78±4.62 days. Median intraoperative blood loss was 112.92±88.56 mL. No blood transfusion was needed during the operations and only one blood transfusion was performed during the perioperative period. Mean operating time was 259.44±49.84 minutes. Average cost was US$9,875.71±1,873.08. Postoperative short-term complications included short-term ileus (n=3), infection (n=13), leakage of urine (n=11), and lymph fistula (n=7). One late complication of unilateral vesicoureteral anastomotic stenosis occurred. The mean follow-up was 13.42±8.77 months, and no patient developed local or systemic recurrence. The short-term follow-up and small cohort of patients limited our evaluation of outcomes. Conclusions: TELRC with PLND and EION was technically feasible and clinically promising, with a reduced potential harm of postoperative complications. Long-term follow-up and a larger cohort of patients are needed for further study.

Synbiotic of Pediococcus acidilactici and Inulin Ameliorates Dextran Sulfate Sodium-Induced Acute Ulcerative Colitis in Mice

( Mingzhu Wang ),( Longzhou Zhang ),( Huiyan Piao ),( Yuanming Jin ),( Chengdu Cui ),( Xin Jin ),( Lianhua Cui ),( Chunri Yan ) 한국미생물생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.3

Colitis is a major gastrointestinal disease that threatens human health. In this study, a synbiotic composed of inulin and Pediococcus acidilactici (P. acidilactici) was investigated for its ability to alleviate dextran sulfate sodium (DSS)-induced colitis. The results revealed that the synbiotic, composed of inulin and P. acidilactici, attenuated the body weight loss and disease activity index (DAI) score in mice with DSS-mediated colitis. Determination of biochemical indicators found that the synbiotic increased anti-oxidation and alleviated inflammation in mice. Additionally, histopathological examination revealed that colonic goblet cell loss and severe mucosal damage in the model group were significantly reversed by the combination of inulin and P. acidilactici. Moreover, synbiotic treatment significantly reduced the levels of IL-1β, TNF-α, and IL-6 in the serum of mice. Thus, a synbiotic composed of inulin and P. acidilactici has preventive and therapeutic effects on DSS-induced colitis in mice.

Integration of ZnO nanowires in gated field emitter arrays for large-area vacuum microelectronics applications

Long Zhao,Yuxiang Chen,Yuanming Liu,Guofu Zhang,Juncong She,Shaozhi Deng,Ningsheng Xu,Jun Chen 한국물리학회 2017 Current Applied Physics Vol.17 No.1

Addressable field emitter arrays (FEAs) have important applications in vacuum electronic devices. However, it is important to integrate nanowire emitters into a gated structure without influencing the device structure and maintain the excellent field emission properties of nanowire emitters in the FEAs after the fabrication process. In this study, gate-structure ZnO nanowire FEAs were fabricated by a microfabrication process. The structure combines a planar gate and an under-gate, which is compatible with the preparation of ZnO nanowire emitters. The effect of electrode materials on the field emission properties of ZnO nanowires was studied using a diode structure, and it was found that ZnO nanowire pads on indium-tin-oxide (ITO) electrode showed better field emission performance compared with chromium (Cr) electrode. In addition, effective emission current modulation by the gate voltage was achieved and the addressing capability was demonstrated by integrating the ZnO nanowire FEAs in a vacuum-encapsulated field emission display. The reported technique could be a promising route to achieve large area addressable FEAs.

Evolution of E. coli Phytase for Increased Thermostability Guided by Rational Parameters

( Jiadi Li ),( Xinli Li ),( Yuanming Gai ),( Yumei Sun ),( Dawei Zhang ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.3

Phytases are enzymes that can hydrolyze phytate and its salts into inositol and phosphoric acid, and have been utilized to increase the availability of nutrients in animal feed and mitigate environmental pollution. However, the enzymes’ low thermostability has limited their application during the feed palletization process. In this study, a combination of B-value calculation and protein surface engineering was applied to rationally evolve the heat stability of Escherichia coli phytase. After systematic alignment and mining for homologs of the original phytase from the histidine acid phosphatase family, the two models 1DKL and 1DKQ were chosen and used to identify the B-values and spatial distribution of key amino acid residues. Consequently, thirteen potential amino acid mutation sites were obtained and categorized into six domains to construct mutant libraries. After five rounds of iterative mutation screening, the thermophilic phytase mutant P56214 was finally yielded. Compared with the wild-type, the residual enzyme activity of the mutant increased from 20% to 75% after incubation at 90°C for 5 min. Compared with traditional methods, the rational engineering approach used in this study reduces the screening workload and provides a reference for future applications of phytases as green catalysts.

Facile Synthesis of Block Copolymers from a Cinnamate Derivative by Combination of AGET ATRP and Click Chemistry

Chuanjie Cheng,Xiongxiong Bai,Xu Zhang,Ming Chen,Qinghua Huang,Zhongyu Hu,Yuanming Tu 한국고분자학회 2014 Macromolecular Research Vol.22 No.12

An azido- and bromo-containing compound derived from naturally occurring ethyl cinnamate was usedsuccessfully to prepare block copolymers by a combination of ‘activator generated by electron transfer atom transferradical polymerization’ (AGET ATRP) and Huisgen “click” reactions in emulsion. First, azido-end poly(methyl methacrylate)and alkyne-end polystyrene were prepared under AGET ATRP conditions, then, poly(methyl methacrylate) blockpolystyrene (PMMA-b-PS) diblock copolymer was formed by Huisgen 1,3-dipolar cycloaddition. Finally, polystyreneblock poly(methyl methacrylate) block polystyrene (PS-b-PMMA-b-PS) triblock copolymer was synthesizedvia simultaneous AGET ATRP and click reactions, catalyzed by the same copper-based catalyst. The polymers werecharacterized by 1H nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC),which confirmed the successful synthesis of the corresponding polymers.

An evaluation on in-pile behaviors of SiC_f/SiC cladding under normal and accident conditions with updated FROBA-ATF code

Chen, Ping,Qiu, Bowen,Li, Yuanming,Wu, Yingwei,Hui, Yongbo,Deng, Yangbin,Zhang, Kun Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4

Although there are still controversial opinions and uncertainty on application of SiC_f/SiC composite cladding as next-generation cladding material for its great oxidation resistance in high temperature steam environment and other outstanding advantages, it cannot deny that SiC_f/SiC cladding is a potential accident tolerant fuel (ATF) cladding with high research priority and still in the engineering design stage for now. However, considering its disadvantages, such as low irradiated thermal conductivity, ductility that barely not exist, further evaluations of its in-pile behaviors are still necessary. Based on the self-developed code we recently updated, relevant thermohydraulic and mechanical models in FROBA-ATF were applied to simulate the cladding behaviors under normal and accident conditions in this paper. Even through steady-state performance analysis revealed that this kind of cladding material could greatly reduce the oxidation thickness, the thermal performance of UO₂-SiC was poor due to its low inpile thermal conductivity and creep rate. Besides, the risk of failure exists when reactor power decreased. With geometry optimization and dopant addition in pellets, the steady-state performance of UO₂-SiC was enhanced and the failure risk was reduced. The thermal and mechanical performance of the improved UO₂-SiC was further evaluated under Loss of coolant accident (LOCA) and Reactivity Initiated Accident (RIA) conditions. Transient results showed that the optimized ATF had better thermal performance, lower cladding hoop stress, and could provide more coping time under accident conditions.