• Korean Chemical Engineering Research
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• 제58권2호
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• pp.248-256
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• 2020

본 연구에서는 폭발위험장소의 방폭설비 설치를 위해 필요한 가스폭발위험범위 예측모델 개발을 수행하였다. 이를 위해 12개의 가연성가스에 대한 1,200개의 폭발위험범위 데이터를 생성하였다. 가스폭발위험범위를 출력변수로 설정하였고 데이터 생성과정에서 필요한 12개의 변수를 입력변수로 설정하였다. 다중 회귀, 주성분 회귀, 인공신경망 기법을 이용해 예측모델을 개발하였다. 각각 모델의 예측 성능을 비교한 결과, 평균절대퍼센트오차(MAPE)는 각각 44.2%, 49.3%, 5.7%이고 평균제곱근오차(RMSE)는 1.389 m, 1.602 m, 0.203 m로 나타났다. 결과를 통해 인공신경망이 가장 우수한 성능을 보여주었고 가스폭발위험범위 예측을 위한 최적 모델이라는 것을 확인하였다.

• 대한물리의학회지
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• 제18권4호
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• pp.57-66
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• 2023

PURPOSE: This research investigated clinical hazardous components and analyzed the proportion of sarcopenia among young Korean women. METHODS: The cross-sectional study included 1,236 women aged 20 to 29 years, categorized into two groups according to their skeletal muscle mass index (SMI). Of these, 20 participants were placed in the sarcopenia group, while 1,216 were included in the normal group. The analysis involved hazardous components including body dimensions, clinical indicators, and behavioral trait variables: height, weight, body mass index, waist circumference, skeletal muscle mass index, systolic and diastolic blood pressure, blood laboratory tests assessing fasting glucose, triglycerides, total cholesterol, as well as smoking habits and alcohol consumption. Complex sampling analysis was used to analyze the proportion and hazardous components of sarcopenia. RESULTS: The proportion of sarcopenia was at 1.76% (95% of CI: 1.08-2.83). Anthropometric measurements, such as height, BMI, and WC, exhibited significant differences between the groups (p < .05). However, there was no significant difference in weight (p > .05) between the two groups. Among the clinical indicators, SBP, DBP, FBG, serum triglycerides, and total TC found to be significant hazardous components for sarcopenia within both groups (p < .05). Smoking status as a behavioral trait was significant as well (p < .05), unlike alcohol consumption (p > .05). CONCLUSION: This study discerned both the proportion of sarcopenia and the hazardous components associated with it among community-dwelling women of a young age.

• 한국대기환경학회지
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• 제28권5호
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• pp.527-537
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• 2012

The increasing consumption of pseudo-petroleum products (PPP) has been disturbing the national petroleum market. The use of PPP lead to tax evasion, disturbance of sound trading principles, component corrosion of cars, and explosion accident. Also, PPP have emitted hazardous air pollutants (HAP) including the carcinogenic aromatic hydrocarbons, PAHs and aldehydes more than regular-petroleum products. It thus has potentials to cause many environmental and health care problems. In this study, benzene, toluene and xylene emissions from road transport vehicles due to the use of pseudo-gasoline are estimated for the year 2008. The results of our study provide emission estimates of benzene, toluene and xylene for the year as 405, 1,711, 717 tonne/yr, respectively for regular-gasoline. BTX emissions are calculated as 452~515, 1,882~2,264 and 732~752 tonne/yr when the amount of pseudo-gasoline is estimated to account for 6~13% for regular-gasoline consumption. BTX emissions increased as much as 12~27, 10~32, 2~5% by using pseudo-gasoline. It is found that the pseudo-gasoline should be the key component to produce HAP in urban area.

• 방사성폐기물학회지
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• 제19권1호
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• pp.141-160
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• 2021

Unit 1 of the Kori Nuclear Power Plant (NPP) and Unit 1 of the Wolsong NPP are being prepared for decommissioning; their decommissioning is expected to generate large amounts of intermediate-level, low-level, and very low level Waste. Mixed waste containing both radioactive and hazardous substances is expected to be produced. Nevertheless, laws and regulations, such as the Korean Nuclear Safety Act and Waste Management Act, do not define clear regulatory guidelines for mixed waste. However, the United States has strictly enforced regulations on mixed waste, focusing on the human health and environmental effects of its hazardous components. The U.S. Nuclear Regulatory Commission and the U.S. Department of Energy regulate the radioactive components of mixed waste under the Atomic Energy Act. The U.S. Environmental Protection Agency regulates the hazardous waste component of mixed waste under the Resource Conservation and Recovery Act. In this study, the laws, regulations, and authorities pertaining to mixed waste in the United States are reviewed. Through comparison and analysis with waste management laws and regulations in Korea, a treatment direction for mixed waste is suggested. Such a treatment for mixed waste will increase the efficiency of managing mixed waste when decommissioning NPPs in the near future.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1163-1168
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• 2003

The structures of molecular species of galactolipids, such as monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG), isolated from wheat flour have been investigated using negative-ion electrospray ionization (ESI) mass spectrometry interfaced with high performance liquid chromatography (HPLC). According to the result of HPLC analysis, MGDG and DGDG were found to consist of mixtures of five and four molecular species, respectively. The galactolipids have been also analyzed to determine their fatty acid compositions, using HPLC/ESI-MS combined with in-source (or cone voltage) fragmentation. HPLC/ ESI-MS is very useful for one-step analysis of mixtures of galactolipids with a small sample quantity. Especially, the carboxylate anions produced in in-source fragmentations of the negative-ion of each component separated by HPLC provide valuable information on the composition of its fatty acyl chains.

• 품질경영학회지
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• 제30권4호
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• pp.164-173
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• 2002

The first product liability laws went into effect in Korea in July 2002. A person who suffers personal injury or damage to property due to defects in a product may sue both the manufacturer and the seller of the product under the principles of Korea tort law. This paper presents an integrated methodology which is called the QDRD(Quality deployment and reliability deployment) for hazards analysis in new product designs. QDRD applies QFD, FMEA and FTA to identify the hazards component, hazardous situations and hazardous events which could lead to an accident. An example is provided to demonstrate hazards analysis on a product using the QDRD method.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2004년도 ISMP Pb-free solders and the PCB technologies related to Pb-free solders
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• pp.201-209
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• 2004

As the European Community's Directive on the Restriction of Hazardous Substances in Electrical and Electronic Equipment banning lead (Pb) in electronics products will take effect on July 1, 2006, most electronics manufacturers will be commencing with volume production of Pb-free components by the middle of 2004. Electrodeposited pure tin finishes on electronic components are a leading contender to replace the industry standard tin-lead. Commensurate with this shift will be a somewhat steep learning curve as manufacturers adapt a variety of equipment and processes to contend with the issues surrounding this critical, industry-wide material conversion. Since the electrodeposited finish directly influences the critical reliability characteristics of the component itself, the nature of the Pb-free component finish must be well characterized and understood. Only through a thorough examination of the attributes of the electroplated tin deposit can critical decisions be made regarding component finish reliability. This paper investigates the properties of electrodeposited tin that may have an effect on component reliability, namely, grain structure (size and shape), oxide formation, tin whisker formation, and solderability. Data will be presented from laboratory and production settings, with the objective being to enable manufacturers to draw their own conclusions regarding previously established perceptions and misconceptions about electrodeposited tin properties.

• 한국염색가공학회지
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• 제33권2호
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• pp.49-63
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• 2021

In this study, a convenient approach for sensitive, quick and simple detection of hazardous acids was investigated. A series of azo dyes were synthesized and applied as a chemosensor for the acid detection both on fibers and in solution. Various aniline, benzothiazole or isoxazole derivatives were used as diazo component and coupled with N-benzyl-N-ethylaniline or 2,2'-(phenylimino)bis-ethanol to give azo based dyes. The acid sensing phenomenon was observed by naked-eye and detection was further confirmed by UV-Vis spectrophotometer and hue difference(ΔH^*) evaluation. The developed sensors showed a distinct and quick color change from yellow to magenta by addition of trace amounts of the hazardous acids. The absorption maxima was shifted to a longer wavelength by 70 ~ 150nm and hue difference(ΔH^*) was 60 ~ 120°. A cotton fiber coated with Dye 1 exhibited excellent storage stability under various temperature(-30 ~ 43℃) and humidity(30 ~ 80%) conditions without discoloration and fading of the fiber sensors. Also the acid sensing properties were maintained.

• 해양환경안전학회지
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• 제28권spc호
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• pp.1-10
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• 2022

국내외 해상 위험·유해물질(Hazardous and Noxious Substances, HNS) 물동량이 증가함에 따라 HNS 유출 사고의 위험성이 점차 높아지고 있다. 해상에 유출된 HNS는 해양생태계 파괴를 비롯한 해양환경 오염 및 인명피해를 유발하며, 화재 및 폭발 등을 동반한 2차 사고 발생 가능성도 존재한다. 따라서 해상 HNS의 신속한 탐지와 각 물질 특성에 적합한 방제전략을 수립해야 한다. 본 연구에서는 초분광 원격탐사에 기반한 지상 HNS 유출 실험 과정 및 탐지 알고리즘 적용 결과를 제시하고자 한다. 이를 위해 프랑스 브레스트 지역의 야외 풀장에서 스티렌을 유출한 후 초분광 센서를 활용한 동시 관측을 수행하였다. 순수 스티렌 및 해수 스펙트럼은 주성분 분석(principal component analysis, PCA) 및 N-Findr 기법을 적용하여 추출하였으며, 또한 spectral distance similarity (SDS), spectral correlation similarity (SCS), spectral similarity value (SSV), spectral angle mapper (SAM)을 포함한 분광정합 기법을 적용하여 초분광 영상 내 화소들을 스티렌 및 해수로 분류하였다. 그 결과 SDS 및 SSV 기법이 우수한 스티렌 탐지 결과를 보여주었으며, 스티렌 총 면적은 약 1.03 m²로 추정되었다. 본 연구는 해상 HNS 모니터링에 주요 역할을 할 것으로 기대된다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.71-77
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• 2005

Combustion of RDF and wastewater sludge was performed in a 0.1MWth bench scale circulating fluidized bed combustor(CFBC), Combustion characteristics of the RDF and sludge mixture demonstrated stable combustion conditions. Component analysis, Combustion characteristics was measured before and after the test, and applications for commercial 1MWe CFBC boiler were prepared. The release of hazardous components such as $SO_2$ and HCl was relatively low values of 50 and 150ppm, respectively.