• Journal of Korean Society of Environmental Engineers
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• v.39 no.4
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• pp.208-213
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• 2017

In this study, four inorganic pollutants (cadmium, chromium, manganese, lead), that could cause contamination events in drinking water distribution system, were selected and batch tests were carried out to determine the "minimum response concentration (MRC)", a part of Korean Contamination Warning system establishment. As the results, the minimum response concentration of cadmium was found to be 0.05 to 0.08 mg/L (0.005 mg/L : water quality standard) and that of chrome was 0.03 mg/L (0.05 mg/L). And the minimum reaction concentration was 0.005 mg/L for manganese (0.05 mg / L for water quality) and 0.02~0.08 mg/L for lead (0.01 mg/L).

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.13-23
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• 2014

Geotechnical evaluation on the reactive drain pile which can achieve simultaneously both the soft ground improvement and the remediation of contaminated pore water in reclamation site was performed. Applicability of steel-making slag used as a inside reactive material was confirmed. To investigate the consolidation characteristics of the soft ground improved by reactive drain pile, testing devices to form and install the reactive drain pile were developed and laboratory tests were performed according to the existence of outside sand drain and the length of impermeable barrier. Test results showed that the consolidation time was decreased as the shortening of impermeable barrier. However, the effect of outside sand drain on consolidation time was dominant compared with the length of impermeable barrier.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.901-906
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• 1997

Ultrafine silicon dioxide($SiO_2$) powder was prepared from tetraethylorthosilicate(TEOS) by the gas-phase reaction. The effects of reaction temperature, flow rate of gas, TEOS concentration, and preheating temperature of reactants on the particle size were investigated. As the reaction temperature increased, average particle size of the silicone dioxide powder became smaller. Smaller particles were also obtained with decreasing the residence time of reactants in the reaction zone. Larger particles having narrow size distribution were produced with the high concentrations of the reactants. The effect of the preheating temperature was not considerable on the average particle size. The range of average particle size was from 30 nm to 58 nm depending on experimental conditions.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.214-219
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• 1993

Properties of the antioxidative fraction isolated from browning reaction product (BRP) that were obtained from 2 M L-ascorbic acid (AsA) solution (adjusted to pH 7.0) by heating for 25 hrs at $85^{\circ}C$ were investigated. Both of dialyzable and nondialyzable fraction isolated from BRP showed antioxidative effect. Dialyzable fraction has stronger antioxidative activity than nondialyzable. Dialyzable fraction was divided into the three fractions (A, B, C) by gel filtration. Among these fractions, the fraction (A) that had the highest reducing power and lowest browning drgree had lowest antioxidative activity. The fraction (C) that had lowest reducing power and highest browning degree showed strongest antioxidative effect. In the UV-visible spectrum of these fractions, the maximum absorption wavelengths of fraction A and B were 266.1 and 257.4nm, respectively, and fraction C showed a weaker absorption peak at 274.8nm. Infrared (IR) spectrum results showed that all fractions (A, B, C) had both hydroxy and carboxylic groups, and fraction B and C had carboxylic ester group.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.84-89
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• 2000

생산 현장뿐만 아니라 일상생활의 여러 곳에서 환경을 악화시키는 유해물질이 배출되어, 그를 위한 대책이 초미의 관심사로 되어있다. 종래 다종다양한 유해물질 중에서 일부의 기체상의 물질에 대해서는 그 성질에 따라 연소나 촉매를 사용한 화학적 처리 활성탄 흡착 등의 물리적 처리가 실시되어 왔지만 근년 대기중에서의 방전현상에 수반하여 발생하는 플라스마에 의한 화학반응을 사용한 처리방식이 많은 연구기관에서 시도되고 그 중에는 종래 방식으로는 곤란했던 물질(예를 들면 프론가스)의 분해ㆍ무해화 처리로 실용화된 예도 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.87-88
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• 1999

최근 들어 서울을 중심으로 한 수도권 지역에서는 여름철 오존주의보 발령이 빈번해지면서 광화학 반응에 의한 대기중 오존농도 상승에 많은 관심을 보이고 있다. 휘발성 유기물질 (Volatile Organic Compounds)은 광화학 반응을 통해 오존을 생성시키는 대표적인 대기오염 물질로 알려져 있으며 주로 자동차, 석유정제, 석유화학, 도장산업 등에서 배출되는 것으로 알려져 있다. 이렇나 VOC는 $NO_x$와 함께 대기중 오존농도 저감을 위한 대상물질로써 NOx 배출량 규제와 동시에 VOC 농도 및 특성 또한 면밀히 검토되어야 한다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.67-69
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• 1999

산성물질들은 구름이나 안개가 생성될 때 내부로 녹아 들어가거나, 비가 내릴 때 녹아 들어가 구름, 안개, 비 중에 많은 양이 존재하며, 이 과정이 기체상 물질들이 대기 중에서 제거되는 주요한 과정이다. 구름이나 안개, 비 중에서 직접 산성오염물질이 생성되는 액상반응도 있고, 주로 아황산가스의 산화반응이 기여하고 있다고 알려져 있다(Hegg and Hobbs, 1978). 이렇게 생성된 대기 중 산성물질들은 대기에서 지표면으로 내려와 식물, 하천수, 호소수, 토양, 건축물 등에 영향을 준다.(중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.1-12
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• 1999

식물생육에 필요한 모든 물질 가운데 가장 많이 요구되는 것이 물이다. 물은 가장 많이 흡수하는 물질인 동시에 가장 많이 소실되는 물질이기도하며 또한 가장 다양한 기능을 가진 물질이기도 하다. 모든 식물은 그들의 생장과 분화과정에서 물의 공급량에 대하여 매우 예민한 반응보인다. 이러한 민감한 반응은 고착생활을 하는 식물이 주어진 생육환경의 조건을 감수하면서 수분 결핍이나 건조로부터 스스로 보호하려는 필수적인 현상이다. (중략)

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.108-115
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• 2023

Although hydrazine is an excellent liquid propellant, caution is required during storage and handling due to its high toxicity and reactivity. Safety guidelines should be established in consideration of the chemical reactivity by unintended leakage. In this study, the status of hydrazine facilities at launch site and safety standards for storing and handling were investigated and then, the reactivity between chemicals and hydrazine was analyzed. As a result of the analysis, hydrazine has reactivity with the exception of fuel oil. This paper emphasizes the imperative nature of constructing a dedicated hydrazine storage facility. Ensuring compatibility between hydrazine and the materials used in storage containers and handling equipment is crucial to prevent undesired reactions that could compromise safety. It was intended to be used as basic data to secure the range safety when handling hydrazine.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.70-77
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• 2003

Theoretical estimation of overall stoichiometry for the microbial degradation of hazardous organic compounds is described. Half-reaction method based on microbial energetics was used in the theoretical estimation. In addition to the half-reaction method, other theoretical methods such as intermediate formation, oxygenation reaction, and estimation of the standard free energy of formation by group contribution theory were also applied. As a case study, the application of these methods was demonstrated for the estimation of microbial kinetics in the biodegradation of phenanthrene which was chosen as a model hazardous organic compound along with glucose and hexadecane. The cell yield, oxygen requirement, nitrogen requirement, and mineralization ratio could be estimated from the overall stoichiometry. It is believed that these theoretical estimation methods are useful tools for practical design and assessment of bioremediation of soil and groundwater contaminated with hazardous organic compounds.