• 한국환경생태학회지
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• 제29권1호
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• pp.81-87
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• 2015

This study was carried out in the peatland for estimating the paleoenvironment based on the analysis from its fossils plant and radiocarbon at the Hwayang-ri, Hyeondeok-myeon, Pyeongtaek-city, South Korea. Variety of fossil was collected from the peatland which could discriminated with naked eye and sorted into seeds, leaves, stems from four-stage of standard sieve. During analysis for the large plant fossil within the peatland, the dead plants were largely divided into 3 fossil zones according to its peatland. In the fossil zone III (the oldest layer; 6,970~6,070 yr $C^{14}$ B.P.), the observation of leaves of hydrophyte such as Trapa sp. and stems of Alnus japonica which appeared in wetland means that the environment was influenced by the climate changes such as rainfall increasing and sea level rise. In the fossil zone II (the middle layer; 6,070~5,800 yr C14 B.P.), the occurrence of Gramineae, Cyperaceae and Fagaceae indicate that the environmental condition might be more or less dry by decreasing rainfall and drop in sea level. The fossil zone I (the recent layer; 5,800~4,540 yr $C^{14}$ B.P.) where lots of herbaceous plants, increasing of Fagaceae, decreasing of A. japonica. and distribution of Pinaceae were showed, was inferred to be repeated both dry and wet environment due to human disturbance.

• Corrosion Science and Technology
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• 제4권4호
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• pp.140-146
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• 2005

Fossil fired power plant produces the electric energy by using a thermal energy by the combustion of fossil fuels as like oil, gas and coal. The exhausted flue gas by the combustion of oil etc. contains usually many contaminated species, and especially sulfur-content has been controlled strictly and then FGD (Flue Gas Desulfurization) facility should be installed in every fossil fired power plant. To minimize the content of contaminations in final exhaust gas, high corrosive environment including sulfuric acid (it was formed during the process which $SO_2$ gas combined with $Mg(OH)_2$ solution) can be formed in cooling zone of FGD facility and severe corrosion damage is reported in this zone. These conditions are formed when duct materials are immersed in fluid that flows on the duct floors or when exhausted gas is condensed into thin layered medium and contacts with materials of the duct walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of those ducts. The frequent shut down and repairing works of the FGD systems also demand costs and low efficiencies of those facilities. In general, high corrosion resistant materials have been used to solve this problem. However, corrosion problems have severely occurred in a cooling zone even though high corrosion resistant materials were used. In this work, a new technology has been proposed to solve the corrosion problem in the cooling zone of FGD facility. This electrochemical protection system contains cathodic protection method and protection by coating film, and remote monitoring-control system.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.335-339
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• 2003

The estimation of seawater intrusion into deep aquifers has been becoming an important subject in terms of site characterization for geological disposal of radioactive waste. Conventional direct-current resistivity methods have been used for ground water explorations and recently have been applied to environmental problems. However, electromagnetic methods are more practical and useful for such a deep investigation. We consider audio-frequency magnetotelluric (AMT) and surface-to-borehole electromagnetic (EM) tomography methods as promising tools for the investigation of deep aquifer. These methods were tested in the Hasunuma area, Chiba Prefecture, Japan. Although the study area is in an urban area, high-quality AMT data were acquired, which was mainly accomplished by night-time data recording and remote-reference data processing. One-dimensional inversion results of the AMT data revealed two extremely conductive zones, which is consistent with the electrical conductivity profile of pore water in core samples. It can be interpreted as the seawater intrusions into both zones. However, the chemical analysis of the groundwater sampled in the deep zone suggests that this groundwater must be fossil seawater that had been confined during sedimentation processes. In addition, the permeability coefficient of the deep layer is very low. Thus the deep conductive zone corresponds to the fossil seawater regarded as being difficult to flow.

• 자원환경지질
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• 제40권3호
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• pp.307-318
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• 2007

지열수의 부존은 화석열수계(fossil geothermal system)의 분포와 밀접한 연관성을 가지므로, 활발한 화석열수계에 의한 광역적인 열수변질대가 분포하는 경상분지 남부지역을 대상으로 GIS 공간통합기법을 적용한 지열 부존 잠재력을 탐사하였다. 연구방법은 화석열수계의 기원 및 분포와 관련된 지질 열수변질대, 열수형 광상 분포, 선구조 밀도, 항공자력도 등 주제도를 작성하고, 현행 온천 분포와의 상관성을 파악하여, 공간통합을 실시하였다. 그 결과 퍼지 연산자 중에서는 ${\gamma}$ 연산자(${\gamma}=0.1$)가 가장 높은 성공비율을 나타내었으며, 일부 지역에서 새로운 지열수 부존 가능성이 예상된다.

• 한국환경과학회지
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• 제11권5호
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• pp.455-461
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• 2002

Polycyclic aromatic hydrocarbons(PAHs) are ubiquitous contaminants in coastal marine environment. PAHs enter estuarine and nearshore marine environment via several routes such as combustion of fossil fuels, domestic and industrial effluents and oil spills. In August of 1997, mussels(Mytilus edulis) were collected at 6 sites near Kori nuclear power plant in order to analyze the PAH content by HPLC with uv/vis detection. Unfortunately, I could not find any living oysters in which I firstly intended to measure the PAH content in the study area. NPTHL and ANCPL were the major dominant PAH compounds in mussels living in the intertidal zone of Kori, Korea, and DahA, BbF, BaP were the next dominant PAH group in mussels in the study area. The mean concentrations of 15 PAH in mussels ranged from 3.2 to 1,680 ppb(mean 105$\pm$60.5 ppb). Compared with other studies world over, the concentrations of carcinogenic PAHs were relatively low in mussels in the study area, even though total PAH content was rather high. According to N/P(Naphthalene/Phenanthrene) ratio(147) and the ratio of 2∼3 ring to 3∼5 ring PAHs(58∼90 %) in mussels in the study area, I expect that the major source of PAHs in this study area is rather fresh petroleum-derived. This study presents preliminary data for the PAH levels in mussels from the intertidal zone of Kori, and the data will hopefully be utilized for the assessment of oil pollution in the East Sea, Korea.

• 해양환경안전학회지
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• 제5권1호
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• pp.47-58
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• 1999

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in coastal marine environment. PAHs enter estuarine and nearshore marine environment via several routes such as combustion of fossil fuels, domestic and industrial effluents and oil spills. In August of 1997, sediment and mussels (Mytilus edulis) were collected at 6 sites near Kori nuclear power plant in order to analyze the PAH content by HPLC with uv/vis detection. The concentrations of 15 PAH in sediment ranged from < 1 to 5,900 ppb ( mean 173.5$\pm$99.7 ppb), and in mussels, from < 0.5 to 4,125 ppb (mean 105$\pm$60.5 ppb). Compared with other studies world over, the concentrations of carcinogenic PAHs were relatively low in both sediment and mussels from the intertidal zone of Kori. This study presents preliminary data for the PAH levels in sediment and mussels from the intertidal zone of Kori, and the data will hopefully be utilized for the assessment of oil pollution in the Southeast East Sea, Korea (especially for the PAHs).

• Journal of Welding and Joining
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• 제16권1호
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• pp.70-76
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• 1998

Most fossil power plants and many critical components will be approaching the end of their nominal design life. At the same time, utilities are finding it economically attractive to extend the use of these plants for several more years, Especially Main steam pipe that operated under high temperature and pressure, often under the more severe operating conditions associated with cycling duty, is most important pipe system and critical component in fossil power plant. To extend the viability of older pipe system and to improve the operation and maintenance reliability, some technologies of precise diagnosis and life management have evolved out of the necessity. The purpose of this study is to descrive the related technologies and show the example of one power plants. The purpose of this study is to descrive the related technologies and show the example of one power plants. The stress analysis was done using ANSYS FEM Code. The branch area from main steam to turbine was the high stressed zone. To evaluate the degradation of the pipe material, replica, visual check, magnetic test, hardness test were done at the welding spot. The degradation level of welding point was E/F, so the remaining life of the welded area was about 0-25%.

• 대한기계학회논문집
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• 제17권6호
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• pp.1556-1571
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• 1993

본 연구에서는 소규모 실험장치(6.6kW)를 이용하여 $NO_x$ 저감방법 중에 가장 효율적인 방법이라 알려진 공기 및 연료의 단계적 연소법 (air and fuel staged combustion)을 이용하여, Fuel-N을 함유하고 있는 연료의 $NO_x$ 의 배출특성을 규명함 은 물론 최적 저 $NO_x$ 연소기술 향상방안을 제시하고자 한다.

• 자원환경지질
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• 제45권4호
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• pp.407-429
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• 2012

도미분지에 위치한 도미-1공과 소라-1공을 대상으로 와편모조류 미화석, 유기물상 분석 및 탄성파자료 해석을 통한 지층대비의 방법으로 연구지역의 층서와 고환경을 해석하고, 그 결과를 일본 북서 큐슈지역의 기존 연구결과와 비교하였다. 생물상변화를 토대로 상부에서부터 Ecozone A, Ecozone B(Barren zone), Ecozone C, Ecozone D(Barren zone)로 각각 4개의 생태층서대로 나누었다. 표준화석에 의한 지질시대는 2개 시추공 모두 하부로부터 에오세 - 올리고세, 마이오세, 플라이오세 - 플라이스토세 시기로 나타났다. 유기물상에 의한 고환경은 상부에서 시작하여 다음과 같이 5개로 나누었다; Association I(Inner neritic), Association II(Freshwater), Association III(Inner neritic), Association IV(Freshwater), Association V(Swamp). 두 개의 시추공 자료를 토대로 일본 측 생층서 자료와 비교 한 결과, Heteraluacacysta campanula, Tubiosphaera galatea 등의 에오세 - 올리고세 표준화석이 양측 연구 모두 동일하게 나타나고, 두 지역의 군집조성이 유사함을 확인하였다. 이는 도미분지와 일본의 북서 큐슈 지역의 고제3기층 발달사에 서로 연관성이 있음을 시사한다.

• 한국대기환경학회지
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• 제24권2호
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• pp.220-228
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• 2008

Toluene adsorption characteristics in the adsorption bed packed with activated carbon fiber (ACF) were studied. Experimental apparatus is composed of VOC generation equipment, adsorption bed, and analytical instrument. Breakthrough characteristics were investigated with length of the adsorption bed which consisted of 3 or 5 sheets of the ACF and flow rate when toluene concentration are 400 ppm and 800 ppm respectively. When mass transfer zone (MTZ) comes out of the adsorption bed, toluene concentration is increased sharply and reached plateau region by saturation. Experimental results are compared with semi-empirical gas adsorption model proposed by Yoon and Nelson. In order to investigate the movement of the MTZ with adsorption time in the adsorption bed packed with ACFs, weight increment of each ACF was measured with the location of ACF at each run. When the weight increment of ACF by toluene adsorption which located at the exit of the bed reaches about 20%, toluene started to be detected.