• 항공우주시스템공학회지
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• 제13권4호
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• pp.10-17
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• 2019

This study is concerned with a numerical analysis based on the finite element method to describe the effect of midplane delamination in smart laminated composite plate structures. A new finite element model for centrally located delamination and healthy section was developed and coded in Matlab. The transient analysis of delaminated composite plate with integrated Active Fiber Composite (AFC) was investigated in the present article. The formulation of the governing equation was based on the minimum total potential energy approach. The Newmark time integration technique was employed to solve the differential equations. A parametric study on the effects of boundary conditions and AFC patch location, in presence of delamination on the laminated plate were studied.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.118-118
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• 2008

The phylogenetic diversity of microbial communities in calcareous mats from Spearfish Creek, a freshwater stream located in the Black Hills of South Dakota, was examined using PCR-based 16S rDNA sequence analysis. In this study, two types of calcareous mats were compared: mature mats formed on the natural substrate of rock surfaces and developing mats on an artificial substrate of glass slides. Among 63 unique isolates from a clone library of 16S rRNA genes from mature mat samples, there were 8 phyla of Bacteria represented. The predominant phylum was Proteobacteria (48%), with the $\beta$ subclass being the largest group. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes from slide samples collected at intervals for four months showed considerable diversity of the microbial community from the earliest stages of community development. Amplicons isolated from DGGE gels and sequenced indicated that community succession has occurred without increasing microbial diversity. However, light microscopic analysis revealed a significant increase in microbial cell density throughout the community development. Scanning electron microscopy of mat samples provides evidence that diatoms are also important members of calcareous mat communities.

• 한국환경보건학회지
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• 제41권6호
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• pp.369-379
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• 2015

Objectives: The lack of reliable information on environmental pollution and health impacts related to asbestos contamination from abandoned mines has drawn attention to the need for a community health study. This study was performed to evaluate asbestos-related health symptoms among residents near abandoned asbestos mines located in the Chungcheong Provinces. In addition, exposure assessment for asbestos is needed although the exposure to asbestos was in the past. Methods: Past exposure to asbestos among inhabitants near abandoned asbestos mines was estimated by using surface sampling of deposited dust in indoor and outdoor residences. A total of 54 participants were divided into two groups with (34 cases) and without (20 controls) diseases related to asbestos. Surface sampling of deposited dust was carried out in indoor and outdoor residences by collecting 105 samples. Deposited dust for sampling was analyzed by polarization microscope (PLM) and scanning electron microscope?energy dispersive x-ray spectrometer (SEM-EDX) to detect asbestos. Subsequently, the elements of the deposited dust with asbestos were analyzed by SEM-EDX to assess the contribution of sources such as abandoned mines, slate and soil. Results: Among the 105 samples, asbestos was detected by PLM in 29 (27.6%) sampling points, and detected by SEM in 56 (48.6%) sampling points. Asbestos in indoor residences was detected by PLM in four sampling points, and by SEM in 12 sampling points. Asbestos detection in indoor residences may be due to ventilation between indoors and outdoors, and indicates long-term exposure. The asbestos detection rate for outdoor residences in the case group was higher than that in the control group. This can be explained as the case group having had higher exposure to asbestos, and there has been continuous exposure to asbestos in the control group as well as the case group. Conclusion: Past residential asbestos exposure may be associated with asbestosis among local residents near abandoned asbestos mines. Odds ratios were calculated for asbestos detection in outdoor residence by logistic regression analysis. Odds ratio between asbestos detection and asbestosis pulmonum was 3.36 (95% CI 0.90-12.53) (p=0.072), adjusting for age, sex, smoking status and work history with multi-variable logistic regression by PLM analysis method.

• 환경영향평가
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• 제16권2호
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• pp.143-156
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• 2007

This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

• 자원환경지질
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• 제46권4호
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• pp.291-300
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• 2013

북한의 광물자원 부존량 및 생산 현황을 종합하면, 북한에서 부존규모가 큰 주요 광물종은 마그네사이트, 석회석, 석탄(무연탄), 인상흑연, 철, 금, 은, 연, 아연 등으로 판단된다. 기타 동, 몰리브덴, 중석, 인광석 등이 잠재성이 큰 광물자원으로 평가된다. 북한의 광물자원 수출 대상국은 중국으로서 주요 수출 광물로는 무연탄, 철광석이 75%로서 압도적으로 우세하다. 수출국은 중국 외 EU국가이나, 중국 수출이 70%에 달한다. 북한은 금 매장량 약 2,000톤과 연간 생산량은 약 2 톤(금속기준)이며, 대표적 광산은 수안, 홀동, 대유동광산이며, 6개 금 제련소가 운영 중이다. 철 매장량은 Fe 63.5% 기준으로 약 43억 톤, 연간 생산량은 약 5백만 톤, 주요 철광산은 무산, 리원, 북청, 은율, 신원, 재령광산이며, 7개 제철소 및 제강소가 운영 중이다. 연-아연 매장량은 금속 기준으로 연이 약 4.7백만 톤, 아연이 15백만 톤, 연간 생산량은 금속 기준 연이 약 26,000 톤, 아연이 금속 기준 50,000 톤이다. 주요 연-아연 광산은 검덕, 은파, 성천광산이며, 6개 제련소가 운영 중이다. 마그네사이트 매장량은 MgO 95% 기준으로 약 28억 톤, 최근 연간 생산량이 정광 기준 150,000 톤, 주요 광산은 룡양, 대흥, 쌍룡광산이며, 5개 마그네슘 내화물공장이 가행중이다. 인회석 매장량은 $P_2O_5$ 30% 기준으로 약 3.4억 톤, 최근 연간 생산량은 원광석 기준 약 300,000 톤, 주요 광산은 대대리, 동암, 풍년광산이다. 석탄은 북한에서 중요한 전략 연료광물자원으로 인식되고 있으며, 주 에너지원이다. 석탄 매장량은 186억 톤, 연간 생산량은 2천만 톤이다. 주요 석탄광산은 평남에 집중되고 있으며, 직동광산이 북한에서 가장 큰 석탄광산이다.

• 화약ㆍ발파
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• 제42권2호
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• pp.29-41
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• 2024

세계 성장에 따른 금속 광물의 수요 증가와, 지속된 지표 부근의 광물 개발로 인해 고심도 광산에 존재하는 광석을 안전하고 효율적으로 채굴하는 방법이 필요하다. 고심도 광산에서는 공동 주변에 집중되는 응력이 증가하며, 이로 인해 촉발지진이나 록버스트와 같은 문제가 발생할 수 있다. 또한 심부에 위치한 단층에 발파로 인한 에너지가 전달되면 단층의 미끄러짐으로 인해 지진이 발생할 수 있으며 이와 같은 사고를 제어하는 것이 고심도 광산 채광법의 핵심이다. 본 기술보고에서는 고심도 광산에서 채광 시 발생 가능한 사고를 제어하고, 생산성을 높일 수 있는 UCB(Underhand Closed Bench) 채광법에 대해 소개하고자 한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.183-193
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• 2006

Several metalliferous and coal mines, including Seojin and Okdong located at the Kangwon province, were abandoned or closed since 1989 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water and soil pollution in the downstream areas. However, no quantitative assessment was made on soil and water pollution by the transport of mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, total and fractional concentrations of heavy metals in mining wastes were analyzed and accordingly the degree of water and soil pollutions in the stream area were quantitatively assessed employing the several pollution indices. Concentrations of Ni, Cd, and Pb in soils near the abandoned coal mine areas were 1,240.0, 25.0 and 1,093.0 mg/kg, respectively, and these concentrations were higher than those in soils near the closed metalliferous mine areas. Also Cu concentrations in soils near the tailing dams were about 1967 mg/kg, which is considered as very polluted level. Results demonstrated that soil at the abandoned mine areas were highly contaminated by AMO, tailing, and effluents of the mining wastes. Therefore, a prompt countermeasure on the mining waste treatment and remediation of the codntaminated water and soil should be made to the abandoned or closed metalliferous and coal mines located at the abandoned mine area.

• 자원환경지질
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• 제31권6호
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• pp.499-508
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• 1998

The Imgok Creek is located in the Gangreung coal field, which has been known that sulfides are more abundant than other coal fields in Korea, and it has been severly contaminated by acid mine drainage (AMD) discharging from the abandoned coal mines, such as the Youngdong, the Dongduk and the Waryong coal mines. The purposes of this study are to synthetically assess the contamination of natural water, stream sediment and cultivated soils, and to provide the basic data for AMD treatment. Geochemical samples were collected in December, 1996 (dry season) and April, 1997 (after three day's rainfall). TDS of the Youngdong mine water was remarkably higher than those of other mine waters. In the Imgok Creek, concentrations of most elements, except Fe decreased with distance by dilution caused by the inflow of uncontaminated tributaries. From the results of NAMDI and $I_{geo}$ calculation, the Youngdong coal mine was the main contamination source of the study area. Groundwater pollution was not yet confirmed in this study and the paddy and farm land soils were also not yet contaminated by mining activity based on the pollution index ranging from 0.27 to 0.47.

• 대한환경공학회지
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• 제27권6호
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• pp.670-674
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• 2005

The respiratory quinone profile was used as a tool for the study on microbial community structure in the mine tailings of abandoned mines over the depth. For the study, the area of Jingok mine located in Bongwha, Korea has been selected. The distributions of Cd, Cu, Pb, Al, Fe and Mn showed the following common patterns; the highest values in the upper part of mine failings (0-20 cm), rapid decrease with increasing depth. The dominant quinone species of the mine tailings were UQ-9 followed by UQ-10, suggesting that microbes had contributed to heavy metal degradation. The quinone contents in mine tailings ranged from 5.0 to 24.9 nmol/kg. The microbial diversity in the upper part of mine tailings (0-40 cm) was higher than that of lower part of mine tailings (100-120 cm).

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권5호
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• pp.25-36
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• 2005

옥동천 유역의 상류에 위치한 명진탄광, 서진탄광, 옥동탄광 등이 1988년 이후 석탄합리화 사업으로 인하여 휴폐광 되었다. 따라서 많은 양의 광산 폐재가 적당한 처리시설이 없이 그대로 유입되어 하류지역의 수질오염을 야기 시킨다. 폐탄광으로부터 유출되는 침출수와 산성광산배수는 pH $2.7\sim4.5$의 강한 산성을 나타내며, 총용존물질은 $1,030\sim1,947mg/L$로 높은 범위를 나타낸다. 또한 Fe, Cu, Cd 같은 중금속의 농도와 음이온인 황산이온 등도 매우 높은 농도를 보인다. 옥동천내에 포함된 중금속의 농도는 Fe>Al>Mn>Zn>Cu>Pb>Cd 순으로 나타났으며, 철의 경우 산성광산배수와 침출수로 부터 옥동천 하류의 수질과 토양의 질을 나타내는 지표가 된다. 구리농도는 풍수기에 공재댐 배출수에서 높은 농도를 나타냈다. 표층수의 수질오염지표는 폐탄광의 산성광산배수가 유입되는 옥동천 본류 상류에서 $16.3\sim47.1$을 나타냈다. 반면에 구광재댐과 신광재댐 및 폐탄광의 배출수가 유입되는 중류에서 $10.6\sim19.5$를, 하류에서는 평균값인 $10.6\sim14.9$를 보여, 상류지역의 폐탄광의 산성광산배수가 옥동천의 주 오염원인 것으로 나타났다.