Numerical simulation of natural convection around the dome in the passive containment air-cooling system

Dong Chunhui,Chen Shikang,Chen Ronghua,Tian Wenxi,Qiu Suizheng,Su G.H. 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.8

The Passive containment Air-cooling System (PAS) can effectively remove the decay heat of the modular small nuclear reactor after an accident. The details of natural convection around the dome, which is a key part of PAS, were investigated numerically in the present study. The thermal dynamics around the dome were studied through the temperature, pressure and velocity contours and the streamlines. Additionally, the formation of the buoyant plume at the top of the dome was investigated. The results show that with the increase of Ra, the lift-off point moves toward the bottom of the dome, and the eddy under the buoyant plume grows larger gradually, which enhances the heat transfer. And the heat transfer along the dome surface with different truncation angles was investigated. As the angle increases, the heat transfer coefficient becomes stronger as well. Consequently, a newly developed heat transfer correlation considering the influence of truncation angle for the dome is proposed based on the simulated results. This study could provide a better understanding of natural convection around the dome of PAS and the proposed correlation could also offer more predictive value in the improvement of nuclear safety.

Simulation on mass transfer at immiscible liquid interface entrained by single bubble using particle method

Dong, Chunhui,Guo, Kailun,Cai, Qinghang,Chen, Ronghua,Tian, Wenxi,Qiu, Suizheng,Su, G.H. Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.6

As a Lagrangian particle method, Moving Particle Semi-implicit (MPS) method has great capability to capture interface/surface. In recent years, the multiphase flow simulation using MPS method has become one of the important directions of its developments. In this study, some key methods for multiphase flow have been introduced. The interface tension model in multiphase flow is modified to maintain the smooth of the interface and suitable for the three-phase flow. The mass transfer at immiscible liquid interface entrained by single bubble which could occur in Molten Core-Concrete Interaction (MCCI) has been investigated using this particle method. With the increase of bubble size, the height of entrainment column also increases, but the time of film rupture is slightly different. With the increase of density ratio between the two liquids, the height of entrained column decreases significantly due to the decreasing buoyancy of the denser liquid in the lighter liquid. In addition, the larger the interface tension coefficient is, the more rapidly the entrained denser liquid falls. This study validates that the MPS method has shown great performance for multiphase flow simulation. Besides, the influence of physical parameters on the mass transfer at immiscible interface has also been investigated in this study.

Chemical constituents from Inula wissmanniana and their anti-inflammatory activities

Chunhui Wang,Xufeng Zhang,Panlei Wei,Xiangrong Cheng,Jie Ren,Shi Kai Yan,Wei Dong Zhang,Hui Zi Jin 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.12

Two new inositol derivatives, 4-acetate-1,2,3,5-tetrakis(2-methyl-2-butenoate) inositol (1) and 3-acetate-1,2,4,5-tetrakis(2-methyl-2-butenoate) inositol (2), onenew flavonolignan 23-o-acetylsilychristin A (3), and onenew thymol derivative 3-hydroxy-4-(2-hydroxy-1-methylethyl)benzoic acid (4), along with 13 known compounds,including ten flavonolignans (5–14) and three thymolderivatives (15–17) were isolated from the aerial part ofInula wissmanniana. The structures of new compoundswere elucidated by detailed spectroscopic analysis,including HRESIMS and 2D-NMR spectroscopic data. Allthe compounds were isolated from this plant for the firsttime. The anti-inflammatory activities of the compoundswere tested against LPS-induced NO production in RAW264.7 macrophages.

Risk perceptions of a population living near a municipal waste incinerator and associated factors with the prevalence of environmental disease

Dong Hyun Kim,Chae Kwan Lee,Jeong Ho Kim,Byung Chul Son,Chunhui Suh,Kunhyung Kim,Byeong Jin Ye 대한직업환경의학회 2022 대한직업환경의학회지 Vol.34 No.-

Clinical and Genetic Features of Brainstem Glioma in Adults: A Report of 50 Cases in a Single Center

Chunhui Zhou,Hao Zhao,Fan Yang,Luokai Huangfu,Chao Dong,Shuwei Wang,Jianning Zhang 대한신경과학회 2021 Journal of Clinical Neurology Vol.17 No.2

Background and Purpose Brainstem gliomas (BSGs) in adults are rare brain tumors with dismal outcomes. The aim of this study was to determine the clinical and genetic features in a series of BSGs and their association with the prognosis. Methods Fifty patients who underwent a stereotactic biopsy between January 2016 and April 2018 at a single institution were collected. Data on clinicopathological characteristics were analyzed and factors associated with patient survival were identified using a Cox regression model. Results The median age at diagnosis was 55.5 years, and 62% of the patients were male. Glioblastoma (44%) accounted for the largest proportion of BSGs, and oligodendroglioma (2 of 50) was rarely encountered. The IDH mutation (6 of 44) occurred infrequently in astrocytomas, and IDH-mutant tumors harbored both ATRX loss and MGMT promoter methylation at a relatively low level. Wild-type IDH astrocytomas were identified as having high rates of 1p/19q codeletion (5 of 38) and loss of heterozygosity 1p (8 of 38) or 19q (8 of 38) only. In diffuse midline glioma H3K27M mutant, MGMT promoter methylation occurred in three of four cases. Patients were offered radiotherapy and/or concurrent/adjuvant temozolomide chemotherapy, and their median survival time was 13 months. Multivariate analysis revealed that a low tumor grade, absence of tumor enhancement, duration of symptoms ≥3 months, Karnofsky performance status ≥70, and ATRX loss conferred a survival advantage. Conclusions Adult BSGs showed different molecular genetic characteristics, but also resembled supratentorial gliomas in their clinical features associated with oncological outcomes.

Developmental and Reproductive Toxicity of Perfluorinated Chemicals

Chunhui Suh(서춘희),Nam-Kyoo Cho,Chang-Hee Lee,Jung-Ho Kim,Hui Dong Kim 대한직업환경의학회 2009 대한직업환경의학회 학술대회 논문집 Vol.43 No.-

채용시 건강진단 폐지 후 배치전 건강진단의 실태

서춘희,이종태,김대환,손병철,이창희,김휘동,안진동 大韓産業醫學會 2008 대한직업환경의학회지 Vol.20 No.3

목적: 산업안전보건법 개정 후 배치전 건강진단의 실시 현황 및 보건관리자의 인식도를 파악하고자 하였다. 방법: 부산과 경남에 위치하는 특수건강진단기관 2개소 에서 2006년 1월 1일에서 2006년 12월 31일까지 배치전 건강진단을 받은 근로자 6,507명을 대상으로 배치전 건 강진단서 판정결과를 검토하였다. 건강관리구분 유소견자 판정을 받은 근로자 330명을 대상으로 전화인터뷰를 시도하여 성공한 185명을 최종 연구 대상으로 하였다. 그리고 동 기관에서 관리하고 있으며 특수건강진단을 실시하는 보건관리대행 사업장 중에서 169개의 사업장 보건 관리자를 대상으로 2007년 5월 1일에서 9월 30일까지 설문조사를 하였다. 결과: 근로자 전화 인터뷰 조사에서 배치전 건강진단 결과 질환 유소견 판정때문에 채용이 거부된 사람은 51명 (27.4%)이었다. 보건관리자를 대상으로 한 설문조사에서 채용시 건강진단의 폐지를 모르는 사업장이 39개(23.1%)였다. 배치전 건강진단을 근로자 채용결정 후 부서배치 전에 실시하는 사업장 73개(43.2%)중에서 그 결과를 부서배치에 활용한다고 응답한 사업장이 63개 (37.3%)였다 질환유소견 판정을 받았을 때 고혈압,당뇨병,고지혈증 등 만성 칠환이 있는 경우 각각 20개(11.8%),21개(12.4%),22개(13.0%) 사업장에서 근로자를 고용하지 않는다고 답했고,업무상 질병과 관련된 청력이상,요추부 방사선 이상소견이 있을 때 각각 76개 (44.4%),75개(43.8%) 사업장에서 근로자를 고용하지 않는다고 답했다. 결론: 채용전 건강진단이 폐지되고 배치전 건강진단에 대한 법 조항이 개정되었음에도 불구하고 사업장에서는 법규에 대한 이해가 불충분하여 여전히 배치전 건강진단이 취업시 불건강자를 가려내는 목적으로 이용되고 있으며,업무 적합성 개념에 대한 이해가 불충분하였다. 따라서 사업주는 배치전 건강진단 실시시기를 준수하고 건강 진단 기관에 배치 예정 업무에 대해 구체적인 정보를 제공하여야 한다. 정부에서는 법규 개정 후 홍보에 힘쓰고,법규 시행 후 적절한 정책 평가도 병행하여야 한다. Objectives: We investigated the status of the preplacement medical examination after the revision of the industrial safety and health law on Oct. 7, 2005 by the Ministry of Labor. Methods: Preplacement medical certificates of 6,507 recruits issued by two hospitals in Busan, Kyeongnam Province from Jan. 1 to Dec. 31,2006 were reviewed. Telephone interviews were performed to the recruits with disease and self-reported questionnaires were administrated to health and safety personnel from May 1 to Sep. 30, 2007. Results: Interviews were conducted with 185(56.1 %) recruits with disease, 51(27.4%) of whom were rejected for employment due to the preplacement medical certificate. The questionnaire survey for the health and safety personnel revealed that 39(22.9%) personnel were unaware of the annulment of the preemployment medical examination. Eighty(48.8%) of the health and safety personnel answered that they performed a preplacement medical examination after employment, and 63(37.3%) made a practical application of the workers' placement. The recruits with chronic conditions were refused employment: 20 (11.8%) due to hypertension, 21 (12.4%) diabetes mellitus and 22(13.0%) hyperlipidemia. The recruits with work-related diseases were also refused employments: 76(44.4%) due to lumbar spine abnormality and 75(43.8%) hearing loss. Conclusions: Despite the annulment of the pre-employment medical examination, a preplacement medical examination was often used to discriminate among healthy and diseased recruits. Employers must respect the law for the point of time of the preplacement medical examination and the payment of cost. The government should publicize the revision of the objectives of the law. We suggest that health professionals elucidate the job fitness through the development of the assessment tools and maintain the confidentiality of recruits.

Chemical constituents of the stems of Celastrus rugosus

Ruijie Chang,Chunhui Wang,Qi Zeng,Bin Guan,Wei Dong Zhang,Hui Zi Jin 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.11

Two new sesquiterpene pyridine alkaloids rugosusinesA and B (1 and 2), and thirty-one known compoundswere isolated from the stems of Celastrus rugosus. The structures of new compounds were elucidated bydetailed spectroscopic analysis, including HR-ESI–MS and2D NMR spectroscopic data. All the compounds wereisolated from this plant for the first time. The cytotoxicitiesof these compounds were tested against SKOV3 and MGC-803 cell lines by CCK-8 method.

Graphene mode-locked femtosecond Cr^2+:ZnS laser with ~300 nm tuning range

Cho, Won Bae,Choi, Sun Young,Zhu, Chunhui,Kim, Mi Hye,Kim, Jun Wan,Kim, Jin Sun,Park, Hyung Ju,Shin, Dong Ho,Jung, Moon Youn,Wang, Fengqiu,Rotermund, Fabian The Optical Society 2016 Optics express Vol.24 No.18

Effect of annealing temperature on resistive switching behavior of Al/ La0.7Sr0.3MnO3 /LaNiO3 devices

Li Juanfei,Wu Lei,Ma Mingyu,Song Ruifeng,Dong Chunhui,Wei Junfang,Li Jinsheng,Wang Xiaoqiang,Li Mingya 한국물리학회 2023 Current Applied Physics Vol.46 No.-

La0.7Sr0.3MnO3 (LSMO)/LaNiO3 (LNO) thin films were deposited successively on Si single crystal by the sol-gel method. The bipolar resistive switching (RS) behavior was studied in Al/LSMO/LNO devices. Obvious current hysteresis was observed, the set (reset) voltage and resistance ratio were modulated by the annealing temperature of LSMO thin films. At the annealing temperature of 750 ◦C, good endurance and retention performance were obtained in the memory device. According to the fitting results of I–V curves, based on Schottky emission model, the conduction mechanisms of Al/LSMO/LNO devices were discussed. Our results may give a valuable insight on developing perovskite-type rare earth manganese oxide.