• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.256-261
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• 2019

The use of military lithium batteries in this field accelerates the generation of internal pressure because the active materials, lithium and the electrolyte, react to form sulfur dioxide gas. This also reduces the amount of electrolyte. In this condition, batteries can 'vent' or 'explode' especially when completely discharged. Such venting and explosion can be regarded as a safety accident, as toxic gases and shrapnel are ejected from the batteries which can harm the user. A DTaQ was carried out in 2017 as a quality problem solution project to solve this safety issue. A protection circuit was thereby developed, which included a micro controller unit (MCU) which can stop battery usage when in an over-discharging state by sensing its low-voltage condition. In 2018, this concept was expanded to lithium batteries for the remote controlled ammunition system. This paper reports results of the improved performance.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2771-2782
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• 2022

When assessing the radiological consequences of postulated accident scenarios, it is of primary interest to determine the amount of radioactive fission gas accumulated in the fuel rod free volume. The state-of-the-art semi-empirical approach (ANS 5.4-2010) is reviewed and compared with a mechanistic approach to evaluate the release of radioactive fission gases. At the intra-granular level, the diffusion-decay equation is handled by a spectral diffusion algorithm. At the inter-granular level, a mechanistic description of the grain boundary is considered: bubble growth and coalescence are treated as interrelated phenomena, resulting in the grain-boundary venting as the onset for the release from the fuel pellets. The outcome is a kinetic description of the release of radioactive fission gases, of interest when assessing normal and off-normal conditions. We implement the model in SCIANTIX and reproduce the release of short-lived fission gases, during the CONTACT 1 experiments. The results show a satisfactory agreement with the measurement and with the state-of-the-art methodology, demonstrating the model soundness. A second work will follow, providing integral fuel rod analysis by coupling the code SCIANTIX with the thermo-mechanical code TRANSURANUS.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.100-100
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• 2012

지식경제부의 청정제조기반 산업원천개발사업의 일환으로 진행 중인 "초고진공펌프 개발" 과제 중 제3세부 과제인 "고진공펌프 종합특성평가시스템 설계, 진단기술 개발" 과제에서 진행되고 있는 연구수행결과를 소개한다. 국내 초고진공펌프 개발 수준의 선진화를 위한 기본적인 초석 확립은 현존하는 모든 진공 발생 장치의 국제적 신뢰성이 있는 완벽한 성능평가의 구현에 있다고 할 수 있다. 고진공펌프개발 총괄 과제의 대명제는 "국제적 신뢰성을 가지는 상용화 제품의 완성"이며, 이를 위한 3세부과제의 추진 방향은 기 완료된 1단계 기술개발에 근거한 1세부과제 및 2세부과제와의 유기적인 infra를 통한 성공적인 지원체계 구축 및 상용화 제품 개발 단계의 모든 신뢰성 확보 전략을 수립, 수행하는 것을 골자로 하고 있다. 또한 2단계 사업 추진 동안 제품 개발 주체인 산업체에 모든 개발된 기술을 적용할 수 있는 기반 제공 및 상용화를 위한 성공적인 기술이전도 포함된다. 상용화 개발 완료 후인 Post Project 기간 동안에 발생할 수 있는 모든 지원체계의 구축도 장기간에 걸친 연구 개발의 연장선상에서 추진되어야 될 것으로 예상된다. 세부 추진내용으로 나노팹 공정현장의 고진공펌프 신뢰성평가의 기본 개념설계를 포함한 현장 데이터의 확보 및 분석 현황, 공정현장의 실제 환경에 투입하기 전 단계의 모든 신뢰성 확보 방안, 터보분자펌프의 경우 파괴실험을 포함한 over speed, shock venting, foreign debris dropping test 등 상용화 단계에 필요한 기본 시험평가 조건을 고찰하고자 한다. 상용화 단계의 내구성 및 신뢰성 확보를 위한 전제 조건은 대외적으로 공표할 수 있는 시험 평가 데이터와 개발 주체에서 기밀 수준으로 유지해야만 하는 민감한 자료의 상시 생산 infra의 구축으로 볼 수 있다. 이러한 고진공펌프개발이라는 과제의 대명제를 완성하기 위하여 추진 연구개발 방향 등 진행형인 2년간의 최종 상용화에 필요한 국제 신뢰성, 공정대응성 확보 등 핵심사업 추진내용 및 infra 구축의 상세개발 로드맵을 완성하고자 한다.

• CELLMED
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• v.6 no.4
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• pp.26.1-26.3
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• 2016

The purpose of this article is to argue that Korean music, Yukjabaegi (six-bit songs), helps us overcome grief. It is not untrue to say that Yukjabaegi is among the greatest types of music in Korea. This is a testament to the prominence of this statue among Han Ak (Korean music, 韓樂). Empathy is an inherent human quality involving all parts of the brain which is also linked to feelings of love. Empathy is created the moment we imagine ourselves in someone else's situation. Moreover, if empathy is good for us, the generation of empathy may actually mobilize our strength. Koreans have superior strength in overcoming grief and difficult situations by singing together. Often Koreans feel that their lives and labors are difficult, they start singing Yukjabaegi because they consider grief and anxiety wear on a person more than hard work. Listening to and singing Yukjabaegi can cheer up people who feel as limp as a rag after hard labor. Tackling reality and venting the experience via creative expression is bound to be healthy. Under a change of the rhythm pattern, Yukjabaegi thus becomes a major form of amusement for those suffering from difficult situations and comes as a true friend to share in our grief with us. Singing together via Yukjabaegi is a time to share grief. Thus, this, author believes that it is related to empathy. It helps us overcome grief by means of music therapy.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.101-106
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• 1999

Open dump of refuse causes groundwater and soil contamination by leachate and air pollution by LFG(Landfill Gas). In this paper, in order to perform a study about reduction of high leachate and LFG collection & control, using a 3-D, 2-phase, transient FDM model, the analysis of simultaneous flow of leachate and LFG has been carried out. In present numerical analysis it is assumed that 58 percents of LFG will evaporate to the ambient air and the recharge rate of a landfill be 12 percent of the average precipitation per year. All other data were excerpted at the point of 1995 when three refuse layers had been buried. From numerical analysis we concluded that maximum head value is approximately 26 mH2O<-에이치투오 (2.52 atm) in the center of the system and that installing venting trench plays an important role in landfill stabilization. Evan with the assumption of three layers constructed and low recharge rate applied, it is found that cumulative leachate and LFG productions will be 15.1 million 세제곱미터, 5.58 billion 세제곱미터, respectively after 40 years.

• Fire Science and Engineering
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• v.18 no.3
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• pp.57-73
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• 2004

Quantitative safety analysis through a fault tree method has been conducted for a fire broken out over the spilling LNG from a pilot LNG tank, which may have 4 types of scenarios causing potentially risky results. When we consider LNG release from venting pipelines as a first event, any specific radius of Low Flammable Limit(LFL) has not been built up. The second case of LNG outflow from the rupture of storage tank which will be the severest has been analyzed and the results revealed various diffusion areas to the leaking times even with the same amount of LNG release. As a third case LNG leakage from the inlet/outlet pipelines was taken into consider. The results showed no significant differences of LFL radii between the two spilling times of 10 and 60 minutes. Hence, we have known the most affecting factor on the third scenario is an initial amount of LNG release. Finally, the extent of LFL was calculated when LNG pipelines around the dike area were damaged. In addition, consequence analysis has been also performed to acquire the heat radiation and flame magnitude for each case.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.31-35
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• 2008

Natural gas vehicles are being applied to city buses for improving air quality in metropolitan and have proved the effective way to reduce the pollutant emissions. Liquified Natural Gas(LNG) has also attempted a vehicle fuel in order to raise the fuel storage density that is a disadvantage of Compressed Natural Gas(CNG). This paper described insulation characteristic of a LNG storage tank. From the results, adiabatic coefficient of a tested tank was around $40J/h{\cdot}^{\circ}C{\cdot}m^2$ and it was the lower level than gas safety regulation limit. Two experimental methods were adopted to justify the evaluation results and they were revealed that the results were very similar to each other. Also, through testing relief valve operation characteristic it was investigated venting amount of boiled off gas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.154-159
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• 2018

Intentional releases occur frequently during maintenance in gas supplying companies, which may result in unpleasant odors, and the possible mistaken belief of a gas accident. Therefore, this study developed a chemical process for effective odorant removal in natural gas using an active chemical that is released intentionally during maintenance and inspection. To develop an effective treatment process for removing the odorant from released natural gas, the effluent concentrations of the odorant in the released gas were measured after a chemical oxidation reaction with a sodium hypochlorite solution in a compact gas scrubbing equipment newly devised in this study. The device was based on a mixed gas vent after the solution inject odorant in the gas through the energy of the venting gas. The cascade combination of a venturi pipe and mixing chamber was developed to remove the odorant effectively from the purposely-released natural gas using an oxidative reaction between the mercaptan compounds (odorant) and the sodium hypochlorite solution. On the other hand, the developed method could be applied limitedly to a relatively small gas release from a low-pressure source. Further studies will be needed to apply the developed process to a large-scale gas release from a high-pressure source.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.258-263
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• 2012

In this paper the Chemical Propulsion Subsystem of COMS is briefly explained and some telemetries acquired by a series operations of CPS during the Launch and Early Operation Phase of COMS are presented. The pressure and temperature of pressurant tank telemetries are compared with the results of the developed computer program. The changes in pressure are due to the two major phases. The first one is the initialization phases of CPS composed of the venting phase to vent the helium gas in the pipe network from the downstream of the propellant tanks to the thrusters for safety, the priming phase to fill the vented pipe network with oxidizer and fuel respectively and then the pressurization phase to pressurize the ullage of propellant tank to regulated pressure. And the other is the apogee engine firings in which COMS CPS is in the orbit raising phase to use helium as a pressurant to keep the pressure of propellant tank as the liquid apogee engine get fired until COMS reached to the target orbit. This program can be applicable to prepare basis design data of the next Geostationary Satellite CPS.

• Korean Journal of Social Welfare
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• v.62 no.1
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• pp.83-107
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• 2010

This study looked into the inner experience of foster mothers who adopted children under 3 months old and found out they were disabled while they were rearing with Van Manen's hermeneutic phenomenological approach. In-depth interviews were used with six foster mothers who live in Seoul, Gwangju, Gyeongsangnam-do, and Jeollabuk-do. The study resulted in a hermeneutic writing with titled "Love of Mothers Who Want to Make Their Children's Dreams Come True" with six essential themes as follows: 'being at a loss wrapped in a dense fog,' 'venting off the frustration,' 'gratitude amid painfulness,' 'bold confrontation with prejudices,' 'disabled children's return to the center of their moms' life,' and 'expectation for their future life.' As they are disabled, foster mothers want to rear their children with more care and attention to make their children's dreams come true. Seen above, this could be interpreted as mothers' love to a life. For foster mothers, the disability of their adopted children is not a burden but an expectation for a new world. They help the children live by themselves. It shows that every child can have his own home.