• 한국산학기술학회논문지
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• 제20권3호
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• pp.35-42
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• 2019

회분식 축합반응에 의하여 폴리에스터 수지를 제조하는 중 소규모 화학 공장에 대하여 공정안전관리제도 (PSM)의 시행에 활용되는 위험성평가 방법들 중의 하나인 K-PSR 기법을 이용하여 위험성 평가 및 분석을 진행하였다. K-PSR 기법은 중 소규모 화학공장에 대한 위험성 재평가 시에 나타나는 인프라 부족에 의한 어려운 점을 보완하기 위하여 KOSHA에서 개발한 위험성 평가 기법이다. K-PSR 기법을 적용하기 위하여 선택된 화학 공장의 전체 공정을 축합반응공정과 희석/여과 공정의 2 개의 검토구간을 설정하고, 이에 대한 4가지 가이드워드(누출, 화재 폭발, 공정 트러블, 및 상해)를 기초로 하여 공정상의 잠재위험을 찾아내어 분류하였다. 연구의 결과로서, 위험도 등급을 고려한 안전조치로는 첫째, 누출 및 화재 폭발의 잠재 위험성을 예방하기 위한 구체적인 조치로서는 노후설비에 대한 비파괴 검사 및 전기설비의 LOTO 절차서의 마련이 반드시 필요한 것으로 확인되었다. 둘째, 열매체 공급 배관에는 압력계 및 온도계를 설치하여 공정 트러블을 최소화하고, 마지막으로 국소배기장치를 설치하여 잠재적인 상해를 예방해야 함을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.102-102
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• 2016

Water, which is most abundant in Earth surface and very closely related to all forms of living organisms, has a simple molecular structure but exhibits very unique physical and chemical properties. Even though tremendous effort has been paid to understand this nature's core substance, there amazingly still lefts much room for scientist to explore its novel behaviors. Especially, as the scale goes down to nano-regime, water shows extraordinary properties that are not observable in bulk state. One of such interesting features is the formation of nanoscale bubbles showing unusual long-term stability. Nanobubbles can be spontaneously formed in water on hydrophobic surface or by decompression of gas-saturated liquid. In addition, the nanobubbles can be generated during electrochemical reaction at normal hydrogen electrode (NHE), which possibly distorts the standard reduction potential at NHE as the surface nanobubble screens the reaction with electrolyte solution. However, the real-time evolution of these nanobubbles has been hardly studied owing to the lack of proper imaging tools in liquid phase at nanoscale. Here we demonstrate, for the first time, that the behaviors of nanobubbles can be visualized by in situ transmission electron microscope (TEM), utilizing graphene as liquid cell membrane. The results indicate that there is a critical radius that determines the long-term stability of nanobubbles. In addition, we find two different pathways of nanobubble growth: i) Ostwald ripening of large and small nanobubbles and ii) coalescence of similar-sized nanobubbles. We also observe that the nucleation and growth of nanoparticles and the self-assembly of biomolecules are catalyzed at the nanobubble interface. Our finding is expected to provide a deeper insight to understand unusual chemical, biological and environmental phenomena where nanoscale gas-state is involved.

• The Plant Pathology Journal
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• 제36권2호
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• pp.170-178
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• 2020

The Lily mottle virus (LMoV) impedes the growth and quality of lily crops in Lanzhou, China. Recently Arabis mosaic virus (ArMV) has been detected in LMoV-infected plants in this region, causing plant stunting as well as severe foliar symptoms, and likely posing a threat to lily production. Consequently, there is a need to develop simple, sensitive, and reliable detection methods for these two viruses to prevent them from spreading. Reverse transcription (RT) loop-mediated isothermal amplification (LAMP) assays have been developed to detect LMoV and ArMV using two primer pairs that match six conserved sequences of LMoV and ArMV coat proteins, respectively. RT-LAMP assay results were visually assessed in reaction tubes using green fluorescence and gel electrophoresis. Our assays successfully detected both LMoV and ArMV in lily plants without the occurrence of viral cross-reactivity from other lily viruses. Optimal conditions for LAMP reactions were 65℃ and 60℃ for 60 min for LMoV and ArMV, respectively. Detection sensitivity for both RT-LAMP assays was a hundredfold greater than that of our comparative RT-polymerase chain reaction assays. We have also found this relatively rapid, target specific and sensitive method can also be used for samples collected in the field and may be especially useful in regions with limited or no laboratory facilities.

• 지능정보연구
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• 제20권1호
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• pp.103-119
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• 2014

본 논문은 주식 시장 참가자들의 여러 기업 공시에 대한 다양한 지능적인 반응의 차이점과 거래 행동에 영향을 미치는 주요 정보를 분석하였다. 본 연구는 2000년01월부터 2012년 09월까지 코스닥 시장에 신규 상장을 된 기업과 3가지 공시를(무상증자, 유상증자, 신규 시설 투자) 한 기업들을 대상으로 하였다. 시장 참가자들이 무상증자와 유상증자 공시일 경우에 긍정적으로 반응하고 신규 시설 투자일 경우에 부정적으로 반응하다는 연구 결과가 나왔다. 시장 거래량은 긍정적인 사건 전에 급격히 증가하며 모든 그룹의 참가자들의 매수가 활발히 이루어진다. 부정적인 사건일 경우에 기관 참가자들만 활발한 매수 행동을 보여준다. 종합적으로, 기관들은 모멘텀 전략을 보여주며, 개인과 외국인들은 반대투자전략을 보여준다. 본 논문의 합축성도 논의했다.

• 한국입자에어로졸학회지
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• 제15권1호
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• pp.1-13
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• 2019

Current desulfurization and denitrification technologies have reached a considerable level in terms of reduction efficiency. However, when compared with the simultaneous reduction technology, the individual reduction technologies have issues such as economic disadvantages due to the difficulty to scale-up apparatus, secondary pollution from wastewater/waste during the treatment process, requirement of large facilities for post-treatment, and increased installation costs. Therefore, it is necessary to enable practical application of simultaneous SOx and NOx treatment technologies to remove two or more contaminants in one process. The present study analyzes a technology capable of maintaining simultaneous treatment of SOx and NOx even at low temperatures due to the electrochemically generated strong oxidation of the wet-pulse complex system. This system also reduces unreacted residual gas and secondary products through the wet scrubbing process. It addresses common problems of the existing fuel gas treatment methods such as SDR, SCR, and activated carbon adsorption (i.e., low treatment efficiency, expensive maintenance cost, large installation area, and energy loss). Experiments were performed with varying variables such as pulse voltage, reaction temperature, chemicals and additives ratios, liquid/gas ratio, structure of the aeration cleaning nozzle, and gas inlet concentration. The performance of individual and complex processes using the wet-pulse discharge reaction were analyzed and compared.

• 한국의료질향상학회지
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• 제27권2호
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• pp.73-82
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• 2021

Purpose: This study aims to examine the quality of tuberculosis (TB) care after the 1st to 3rd national quality assessment (QA) program for TB healthcare service in Korea was conducted. Methods: We analyzed Health Insurance Review & Assessment Service (HIRA) claims data of new TB patients during the period of January to June from 2018-2020. The new TB patients were defined as TB patients reported to Korea Centers for Disease Control and Prevention Agency (KCDA). The unit of analysis was the patient. Chi-square tests were used to analyze the differences in indicator value according to the types of medical facilities. The QA indicators of TB care were divided into 3 areas consisting of the following 7 quality indicators: 4 indicators of diagnosis test (the rate of acid-fast bacilli smear, the rate of acid-fast bacilli culture, the rate of Mycobacterium tuberculosis-polymerase chain reaction, drug susceptibility test), 1 compliance of treatment guideline, and 2 indicators of care management of TB patients (encounter rate, day of therapy). Results: The QA program for TB care was conducted among 8,246 patients from 534 facilities in 2020. The value of the 7 quality indicators was shown to increase as a result of the QA program. The indicators of the diagnostic test were all higher than 95%, with the exception of the drug susceptibility test which was 84.8%. Both indicators for care management of TB patients were 88.5%. Conclusion: The quality of TB care has been improving with the implementation of the QA program. In order to continue to improve the quality of TB care, it will be necessary to disclose the results of the QA program in medical facilities in the future.

• 한국대기환경학회지
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• 제19권4호
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• pp.437-449
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• 2003

A multi-functional indoor smog chamber was designed and evaluated to investigate photochemical or water vapor reaction mechanisms of air pollutants. Various smog chamber experiments could be conducted using ambient air or purified air in this smog chamber. The smog chamber consisted of a housing, a Teflon bag, blacklights, injection ports, sampling ports, and utility facilities. The characteristics of light source, the wall losses of air pollutants, and the quality of purified air were experimentally investigated. The maximum NO$_2$ photolysis rate was 1.10 min$^{-1}$ . In a 2.5-m$^3$ Teflon bag, the wall losses of ambient $O_3$, NO, and NO$_2$ were 1.2~2.4$\times$10$^{-3}$ min$^{-1}$ , 0.7~2.0$\times$10$^{-3}$ min$^{-1}$ , and 0.4~2.0$\times$10$^{-3}$ min$^{-1}$ , respectively. The wall loss of ambient particles ranging 0.05 to 0.2 ${\mu}{\textrm}{m}$ was 1.8~5.4$\times$10$^{-3}$ min$^{-1}$ , which was slightly higher than those of ambient gaseous species. The purified air supply system provided high quality of air with NO$_{x}$ < 1 ppb, and total hydrocarbons < 5 ppb.b.

• 한국화재소방학회논문지
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• 제17권2호
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• pp.6-9
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• 2003

공조설비에 의한 실내기류 유동특성은 정상해석에 의해 설치되는 화재감지기의 예상 응답특성과 다른 기류 유동특성을 나타내어 기류변화에 따른 이온화식 연기감지기의 응답특성지연을 규명, 성능위주의 화재감지설비 설계를 위한 기반기술 연구를 수행하였다. 실험은 일정한 연기농도를 가진 기류의 풍속을 변화시켜 이온화식 연기감지기의 기류응답특성을 규명하였다. 실험결과 이온화식 연기감지기의 응답특성은 기류속도와 반비례적인 관계가 있으며 기류속도가 60 cm/s 이상인 경우 응답특성이 예민하게 나타났다. 또한, 석유화학제품의 연소에 의한 연기에 비해 종이류의 훈소화재에 예민한 응답특성을 보이는 것으로 나타났다.

• 대한기계학회논문집A
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• 제26권6호
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• pp.1203-1208
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• 2002

LNG demand has been rapidly increasing in Korea for a variety of reasons including stable supply, non-polluting, and high combustion efficiency characteristics. As a result the construction and expansion of LNG storage facilities have been continuing at a vigorous pace. Korea Gas Corp. (KOGAS) has developed the design technology of the LNG storage tank. One of the most important structural core element of the LNG storage tank is the membrane, made by stainless steel. The membrane to be applied inside of LNG storage tank is provided with corrugations to absorb thermal contraction and expansion caused by LNG temperature. Analytical results have been performed to investigate the strength of the membrane and the reaction farce at the anchor point. Experimental studies are performed to investigate the deformation and strength of the membrane which is designed by Kogas. All experiments are conducted on the basis of RPIS, and we found the results are fully satisfied with the RPIS.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.54-59
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• 2007

In a view of capturing $CO_2$ as a greenhouse gas, an experimental study was conducted on the combustion characteristics of pulverized coal in $O_2$/$CO_2$ environment using TGA/DSC and DTF facilities. The effects of gas composition and concentration on the processes of devolatilization and char burning experienced by coal particles in combustion furnace and on the concentration of products such as $CO_2$, CO and $NO_x$ were observed using TGA/DSC and DTF respectively. As results, it were found that the rate of devolitilation is nearly independent on the $O_2$ concentration if it is over 20% but the char burning rate is a sensitive function of $O_2$ percent, and the two rates can be controlled by $O_2$ concentration in order to be similar with those of air combustion case. It was also found that high concentration $CO_2$ can be captured by oxy-coal combustion and high concentration of CO and low value of $NO_x$ are exhausted in that case. Additionally, NO reducing reaction by CO with char as catalyst was observed and a meaningful results were obtained.