• Title/Summary/Keyword: Nuclear and radiation

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Design of I-123 Nuclide production system (I-123 핵종생산장치 시스템 설계)

  • Jung, Hyun-Woo;You, Jae-Jun;Kim, Byung Il;Chun, KwonSoo;Lee, Ji-Seub;Park, Hyun;Choi, JunYong;Oh, Se-Young;Bang, Sang-Kwon;Lee, Dong Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.496-499
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    • 2014
  • Xe Gas is moved to Target from GPM. It is Used to feasible nuclear reaction from proton of 30MeV Cyclotron being investigated by the Xe-124 Gas target System. This system is divided into four parts. Hardware was constructed by solidworks and Helium Supply is to cool the Havor Foil. Water has the job of cooling down the temperature when Xe Gas is being investigated in the target. Temperature and pressure gauges are attached to be checked easily. GPM(Gas Process Manifold) has the part that prepares to transport Xe Gas. There are Storage Vessel that stores Xe Gas, the cold trap that filters humidity and impurity and lastly storage vessel that temporarily stores Xe Gas. HCS(Helium Circulation System) using the Helium to cleaning and cooling. these parts are used to SIEMENS PLC and Pcvue Program. Because It is more comfortable and easy maintenance.

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The rate that underlying causes of death for vital statistics are derived from the underlying causes of death recorded at death certificates: (a study on the death certificates issued from three university hospitals) (사망진단서(사체검안서) 상의 선행사인으로부터 사망통계의 원사인이 선정되는 비율: (3개 대학병원에서 교부된 사망진단서를 중심으로))

  • Park, Woo Sung;Park, Seok Gun;Jung, Chul Won;Kim, Woo Chul;Tak, Woo Taek;Kim, Boo Yeon;Seo, Sun Won;Kim, Kwang Hwan;Suh, Jin Sook;Pu, Yoo Kyung
    • Quality Improvement in Health Care
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    • v.11 no.1
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    • pp.4-14
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    • 2004
  • Background : To examine the problems involved in writing practice of death certificates, we compared the determination of underlying cause of death for vital statistics using recorded underlying cause of death in issued death statistics. Methods : We collected 688 mortality certificates issue in year of 2,000 from 3 university hospitals. And we also collected vital statistics from ministry of statistics. The causes of death were coded by experienced medical record specialists. And causes of death determined at ministry of statistics for national vital statistics were mapped to causes of death recorded at each death certificates. The rate that underlying causes of death for vital statistics were derived from underlying causes of death recorded at issued death certificates were analysed. Results : 64.5% of underlying cause of death for could be derived from underlying cause of death recorded at issued death certificates, 8.6% derived from intermediate cause of death, and 3.9% derived from direct cause of death. In 23% of cases, underlying cause of death could not be derived using issued death certificates. The rate that underlying cause of death for vital statistics could be derived from underlying cause of death recorded at death certificates was different between 3 university hospitals. And the rate was also different between death certificates and postmortem certificates. We classified the causes of death using 21 major categories. The rate was different between diseases or conditions that caused death too. Conclusion : When we examined the correctness of death certificate writing practice using above methods, correctness of writing could not be told as satisfactory. There was difference in correctness of writing between hospitals, between death certificates and postmortem certificates, and between diseases and conditions that caused death. With this results, we suggested some strategy to improve the correctness of death certificate writing practice.

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Evaluation on the Radiological Shielding Design of a Hot Cell Facility (핫셀시설의 방사선 안전성 평가)

  • 조일제;국동학;구정회;정원명;유길성;이은표;박성원
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.1
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    • pp.1-11
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    • 2004
  • The hot cell facility for research activities related to the lithium reduction of spent fuel, which is designed to permit safe handling of source materials with radioactivity levels up to 1,385 TBq, is planned to be built. To meet this goal, the facility is designed to keep gamma and neutron radiation lower than the recommended dose-rate in normally occupied areas. The calculations peformed with QAD-CGGP and MCNP-4C are used to evaluate the proposed engineering design concepts that would provide acceptable dose-rates during a normal operation in hot cell facility. The maximum effective gamma dose-rates on the surfaces of the facility at operation area and at service area calculated by QAD-CGGP are estimated to be $2.10{\times}10^{-3}, 2.97{\times}10^{-3} and 1.01{\times}10{-1}$ mSv/h, respectively. And those calculated by MCNP-4C are $1.60{\times}10^{-3}, 2.99{\times}10^{-3} and 7.88{\times}10^{-2}$ mSv/h, respectively, The dose-rates contributed by neutrons are one order of magnitude less than that of gamma sources. Therefore, it is confirmed that the radiological design for hot cell facility satisfies the Korean criterion of 0.01 mSv/h for the operation area and 0.15 mSv/h for the service (maintenance) area.

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The Utility of Chatbot for Learning in the Field of Radiology (방사선(학)과 분야에서 챗봇을 이용한 학습방법의 유용성)

  • Yoon-Seo Park;Yong-Ki Lee;Sung-Min Ahn
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.411-416
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    • 2023
  • The purpose of this study is to investigate the utilization of major learning tools among radiology science students and assess the accuracy of a conversational artificial intelligence service program, specifically a chatbot, in the context of the national radiologic technologist licensing exam. The survey revealed that 84.3% of radiology science students actively utilize electronic devices during their learning process. In addition, 104 out of 140 respondents said they use search engines as a top priority for efficient data collection while studying. When asked about their awareness of chatbots, 80% of participants responded affirmatively, and 22.9% reported having used chatbots for academic purposes at least once. From 2018 to 2022, exam questions from the first and second periods were presented to the chatbot for answers. The results showed that ChatGPT's accuracy in answering first period questions increased from 48.28% to 60%, while for second period questions, it increased from 50% to 62.22%. Bing's accuracy in answering first period questions improved from 55% to 64.55%, and for second period questions, it increased from 48% to 52.22%. The study confirmed the general trend of radiology science students utilizing electronic devices for learning and obtaining information through the internet. However, conversational artificial intelligence service programs in the field of radiation science face challenges related to accuracy and reliability, and providing perfect solutions remains difficult, highlighting the need for continuous development and improvement.

A Numerical Model to Evaluate Fire-Resistant Capacity of the Reinforced Concrete Members (화재에 손상된 철근콘크리트 부재의 수치모델 및 내화성능해석)

  • Hwang, Jin-Wook;Ha, Sang-Hee;Lee, Yong-Hoon;Kim, Wha-Jung;Kwak, Hyo-Gyoung
    • Journal of the Korea Concrete Institute
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    • v.25 no.5
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    • pp.497-508
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    • 2013
  • This paper introduces a numerical model which can evaluate the fire-resistant capacity of reinforced concrete members. On the basis of the transient heat transfer considering the heat conduction, convection and radiation, time-dependent temperature distribution across a section is determined. A layered fiber section method is adopted to consider non-linear material properties depending on the temperature and varying with the position of a fiber. Furthermore, effects of non-mechanical strains of each fiber like thermal expansion, transient strain and creep strain are reflected on the non-linear structural analysis to take into account the extreme temperature variation induced by the fire. Analysis results by the numerical model are compared with experimental data from the standard fire tests to validate an exactness of the introduced numerical model. Also, time-dependent changes in the resisting capacities of reinforced concrete members exposed to fire are investigated through the analyses and, the resisting capacities evaluated are compared with those determined by the design code.

Study on Radioprotection of Alliin and Damage Mechanism in Hepatocyte After Irradiation (방사선 피폭 시 간세포의 손상 기전과 알리인의 방어효과)

  • Ji, Tae-Jeong;Kim, Won-Tae
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.623-630
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    • 2016
  • Liver tissue damage by a radiation exposure caused a jaundice and ascitic fluid e form harden atrophy. The reason for this lies in morphological damage of a liver cells. This study tried that observe damage mechanism of the cell organelles. It was especially observed mitochondria, endoplasmic reticulum and nuclear membrane associated with energy metabolizable. also, This study had with a radio-protector development research at the same time. Radio-protector was used to alliin that has an blood flow increase. Cell observation make used of transmission electron microscope(TEM). The result of an experiment, 7Gy of whole body irradiation was caused an inflammation in cell organelles and hypertrophy of the nucleus membrane. After 20 days, The hepatocyte has been observed in a damaged membrane on peroxisome, mitochondria and vacuole of the cell organelles. After 30 days, The hepatocyte has been observed in disconnected ribosomes on a rough endoplasmic reticulum. There was looked a giant lipoblast. There was clearly normal observed a mitochondria and nucleus membrane in the hepatocyte after alliin injection. aslo, It was no damaged the nucleus membrane. therefore, It was identified portion a radio-protector effect from alliin.

Study on the Institutional Control Period Through the Post-drilling Scenario Of Near Surface Disposal Facility for Low and Intermediate-Level Radioactive Waste (중·저준위 방사성폐기물 천층처분시설에서 시추 후 거주시나리오 평가를 통한 폐쇄 후 제도적 관리기간 연구)

  • Hong, Sung-Wook;Park, Jin-Baek;Yoon, Jung-Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.1
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    • pp.59-68
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    • 2014
  • The public's access to the disposal facilities should be restricted during the institutional control period. Even after the institutional control period, disposal facilities should be designed to protect radiologically against inadvertent human intruders. This study is to assess the effective dose equivalent to the inadvertent intruder after the institutional control period thorough the GENII. The disposal unit was allocated with different kind of radioactive waste and the effects of the radiation dose to inadvertent intruder were evaluated in accordance with the institutional control period. As a result, even though there is no institutional control period, all were satisfied with the regulatory guide, except for the disposal unit with only spent filter. However, the disposal unit with only spent filter was satisfied with the regulatory guide after the institutional control period of 300 years. But the disposal unit with spent filter mixed with dry active waste could shorten the institutional control period. So the institutional control period can be reduced through the mixing the other waste with spent filter in disposal unit. Therefore, establishing an appropriate plan for the disposal unit with spent filter and other radioactive waste will be effective for radiological safety and reduction of the institutional control period, rather than increasing the institutional control period and spending costs for the maintenance and conservation for the disposal unit with only spent filter.

Spectral Infrared Signature Analysis of the Aircraft Exhaust Plume (항공기 배기 플룸의 파장별 IR 신호 해석)

  • Gu, Bonchan;Baek, Seung Wook;Yi, Kyung Joo;Kim, Man Young;Kim, Won Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.8
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    • pp.640-647
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    • 2014
  • Infrared signature of aircraft exhaust plume is the critical factor for aircraft survivability. To improve the military aircraft survivability, the accurate prediction of infrared signature for the propulsion system is needed. The numerical analysis of thermal fluid field for nozzle inflow, free stream flow, and plume region is conducted by using the in-house code. Weighted Sum of Gray Gases Model based on Narrow Band with regrouping is adopted to calculate the spectral infrared signature emitted from aircraft exhaust plume. The accuracy and reliability of the developed code are validated in the one-dimensional band model. It is found that the infrared radiant intensity is relatively more strong in the plume through the analysis, the results show the different characteristic of the spectral infrared signature along the temperature, the partial pressure, and the species distribution. The continuous spectral radiant intensity is shown near the nozzle exit due to the emission from the nozzle wall.

Inactivation of Xanthomonas citri subsp. citri and Effect on Infection of Citrus Canker by Gamma Irradiation (감마선에 의한 감귤 궤양병균의 불활성화와 감귤 궤양병 감염에 미치는 영향)

  • Kim, Kyung Nam;Song, Min A;Han, Sang Heon;Song, Seong Joon;Jeun, Yong Chull
    • Research in Plant Disease
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    • v.20 no.4
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    • pp.283-288
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    • 2014
  • Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) has been quarantined by many countries in the world. Recently, the usage of methyl bromide should be limited, application by gamma irradiation on the agricultural production is raised as an alternative method. In this study, the level of gamma irradiation which could decrease of population of Xcc in the suspension or on the surface of citrus fruit was investigated. The $D_{10}$ value of Xcc, which is radiation dose required to reduce the number of the microorganism, was 55 and 28 Gy in the suspension and on the surface of citrus fruit, respectively. Furthermore, disease severity was suppressed on the citrus leaves inoculated with Xcc suspension pre-treated with gamma irradiation. Based on this study, it is suggested that Xcc on the citrus fruit could be eradicated by gamma irradiation and the results of this study may be valuable for application of gamma ray in quarantine activity.

Downregulation of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in human keratinocytes by melanogenic inhibitors

  • Ahn, Kwang-Seok;Lee, Jinseon;Kim, Yeong-Shik
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.780-803
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    • 2003
  • Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB ($\textrm{NF}_{-{\kappa}}\textrm{B}$) activators [e.g. tumor necrosis factor-$\alpha$, interleukin-1, lipopolysaccharides, and ultraviolet light] leads to phosphorylation and degradation of the inhibitory protein, $\textrm{I}_{{\kappa}}\textrm{B}$. Liberated $\textrm{NF}_{-{\kappa}}\textrm{B}$ is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte. In order to demonstrate the possible role of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of $\textrm{NF}_{-{\kappa}}\textrm{B}$ induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with $\textrm{pNF}_{-{\kappa}}\textrm{B}$-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the $\textrm{NF}_{-{\kappa}}\textrm{B}$ activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation was measured with the SEAP reporter gene assay using a fluorescence detection method. Of the Mis tested, kojic acid ($IC_{50}$/ = 60 $\mu$M) was found to be the most potent inhibitor of UVB-upregulating $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in transfectant HaCaT cells, which is followed by niacinamide ($IC_{50}$/= 540 $\mu$M). Pretreatment of the transfectant HaCaT cells with the Mis, especially kojic acid and niacinamide, effectively lowered $\textrm{NF}_{-{\kappa}}\textrm{B}$ binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells. These observations suggest that Mis working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

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