• 한국국방경영분석학회지
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• 제16권1호
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• pp.94-112
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• 1990

The basic mathematical tools are developed to determine the optimum emplacement of limited numbers of scatterable mines on the infantry battlefield. A deterministic model is developed for heterogeneous infantry battalion level battle using APL version 7.0. The Helmbold-type combat equation is applied to claculate comparative casulties, and range dependency is also considered to establish the correlation between attrition rate coefficients and the distance of opposing forces, Based on this deterministic model the effective range for employment of scatterable mines is determined. Because mines are primarily effective when employed in conjunction with direct fire weapons, it is inferred that minefield are best employed when used within the maximum effective range of infantry weapons systems such as the M16Al rifle. The model developed verifies this fact.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.28.4-28
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• 2001

This paper proposes an IR camera system that performs the task of removing mines for humanitarian purposes. Because of the high risks involved, it is necessary to conduct mine detection from the most remote endeavoring. By mating use of infrared ray (IR) cameras, scattered mines can be detected from remote locations. In the case of mines buried in the ground, detection is possible if the peripheral temperature difference is large enough between the ground and mine weapon. As one of the world´s advanced nations in sensor technology, Japan should promote surveys and studies for detecting mines safely by using its advanced remote sensing technologies.

• 한국산업보건학회지
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• 제8권2호
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• pp.254-263
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• 1998

A worker employed in a serpentine mine was found developed mesothelioma as the first case of Korea in 1997. Asbestos was known as a causative agent for mesothelioma. Thus, asbestos contamination in mines could be a big health threat to those workers who were unknowingly exposed. However, there was no report that any minerals found in Korea contained asbestos. This study was carried out to find the presence of any asbestiform fibers in minerals which could be obtained in Korean mines. We examined fifteen minerals from 44 mines which were suspected contaminated with asbestiform fibers. Asbestiform analysis was done with high resolution transmission electron microscope(TEM), with energy dispersive X-ray spectroscope(EDX) and X-ray diffraction(XRD) analyses. Among asbestiform fibers, chrysotile was found in chrysotile, serpentine, talc and pyrophylite specimens from 11 mines. Tremolite was found in tremolite and talc specimens from three mines. Mordenite was found in zeolite specimens from two mines. Wallastonite and sepiolite were found in wallastonite and sepiolite specimens respectively. Crocidolite, antigorite and actinolite were found from talc specimens. But no asbestiform fiber contaminants were found in doromite, vermiculite, limestone, marble, gypsum, kaolin, and clary specimens. Thus, these asbestiform fibers such as such as chrysotile, tremolite, mordenite, crocidolite, antigorite and actinolite could be the responsible agents for the health hazards such as mesothelioma and other cancers.

• Journal of Preventive Medicine and Public Health
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• 제44권1호
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• pp.41-47
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• 2011

Objectives: This study assessed the factors that have an influence on the residents exposed to heavy metals, and we utilized the findings to establish the proper management of abandoned metal mines in the future. Methods: For a total of 258 residents who lived close to abandoned mines in Gangwon-province and Gyeonggi-province, the exposure factors and biomarkers in their blood and urine were comparatively analyzed via multiple regression analysis. Results: The blood levels of lead and mercury and the cadmium levels in urine were found to be higher in the study group than that in the average Korean. For the blood levels of heavy metals according to each exposure factor, all of them were found to be significantly higher in both of the group residing for a longer period of time and the group living closer to the source of pollutants. Multiple regression analysis disclosed that all the heavy metals, except lead, in their blood were significantly reduced in proportion to the increased distance of inhabitancy from the mines. Their other biomarkers were within the normal ranges. Conclusions: We found that the distance between the residential village and the mines was a factor that affects the blood level of heavy metals in the villagers. This finding could be an important factor when developing a management model for the areas that surround abandoned metal mines. (ED note: I much like this important study.)

• 자원환경지질
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• 제42권6호
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• pp.619-626
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• 2009

광물자원의 경우 시장여건 변화에 따라 가격변동이 발생되며, 이에 따른 상업적 환경의 변화로 폐광된 광산이 다시 재개발되는 사례 또한 빈번히 발생하기도 한다. 2003년 이후 국제 광물자원 가격은 급격한 상승이 있었으며 한국의 경우에도 폐광된 광산의 재개발에 대한 필요성이 제기되었고 일부 광산의 경우 재개발이 시행되기도 하였다. 본 고는 폐광산의 재개발과 관련하여 효과적인 광해관리를 위해 어떻게 규제제도를 운영할 것인가에 대한 모색을 목적으로 하고 있다. 이를 위해 최근 발생된 광물자원 가격 변화와 함께, 한국의 폐광산 재개발 가능성 및 계획에 대해 살펴보았다. 또한 광산개발과 광해방지 시 인허가 제도에 대한 검토와 문제점 분석을 실시하였다. 연구결과 광해복구가 이루어진 폐광산의 재개발을 위한 인허가 시 광해방지에 투입된 비용과 재개발 시 기대되는 편익을 비교 검토하는 비용 편익 경제성 평가서의 추가적 제출과 함께, 정부의 <광해방지 기본계획> 수립 시 광해복구사업이 필요한 폐광산 선정과 관련하여 재개발 가능성을 고려한 계획 수립이 이루어지도록 제도 개선이 필요한 것으로 나타났다.

• 지질공학
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• 제18권3호
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• pp.297-302
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• 2008

폐광산 인근의 토양과 광미에서 발생하는 오염원은 중금속과 강산성의 배수가 주요한 원인물질이다. 이러한 오염원들은 인근의 토양까지 오염이 확산되어 결국 사람에게 건강상 유해성을 나타낸다. 본 연구에서는 중금속 오염이 심각한 폐광산을 대상으로 이들의 관리를 최적화하기 위해 요구되는 중금속 오염수준예측을 위한 수학적 접근방법을 시도하였다. 이를 위해 폐광산으로부터의 거리와, pH 및 산화환원전위(ORP)의 경시변화를 조사하여 이들의 상관성을 방정식으로 도출하였다. 대상으로 한 폐광산에 따라 다소의 차이는 보였으나, 60일간의 실험기간동안 변화되는 pH와 ORP는 초기의 pH와 ORP를 기준으로 할 때, 변화율이 $0.95{\sim}1.03$의 범위로 나타났다. 이것은 초기의 pH와 ORP를 기초로 폐광산 인근의 토양에서 발생하는 중금속류의 용출정도를 예측하여 환경영향평가를 실시할 수 있음을 시사하며, 이러한 접근방법은 다른 폐광산에도 적용할 수 있으므로 제거 또는 제어 대상인 중금속류의 관리에 유용하게 사용될 것으로 기대한다.

• 한국식품위생안전성학회지
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• 제17권4호
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• pp.178-182
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• 2002

전국 폐광지역(48곳) 평야지역(8곳) 농산물(280건), 토양(280건), 농경수(48건)를 채취하여 수은 함량은 Mercury analyzer로, 납, 카드뮴, 비소 등 중금속은 습식분해후 ICP, AAS등으로 분석하였다. 본 연구결과, 평야지역에 비해 폐광산지역의 토양에 있어 크롬을 제외한 수은, 납 등 중금속 함량이 더 높았으며 농경수에 있어서는 수은을 제외한 다른 중금속함량이 더 높았다. 폐광산지역의 농산물중 납, 카드뮴 등 중금속 함량은 평야지역에 비해 대체로 높은 편이었으나 구리 함량은 평야지역의 농산물이 다소 높았다. 토양과 농산물중 납 등 중금속함량간의 유의적인 상관관계는 관찰되지 않았다(p>0.05). 앞으로도 식품의 안전성 확보 및 국민건강증진차원에서 폐광산지역의 토양, 농산물중 중금속 함량에 대한 모니터링 사업이 지속적으로 수행되어야 할 것으로 사료된다.

• Geomechanics and Engineering
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• 제11권5호
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• pp.657-670
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• 2016

The energy dissipation of coal under dynamic loads is a major issue in geomechanics and arising extensive concerns recently. In this study, dynamic loading tests of coal were conducted using a split Hopkinson pressure bar (SHPB) system, the characteristics of dynamic behavior and energy dissipation of coal were analyzed, and the mechanism of energy dissipation was discussed based on the fracture processes of coal under dynamic loads. Experimental results indicate that the energy dissipation of coal under dynamic loads has a positive linear correlation with both incident energy and dynamic compressive strength, and the correlation coefficients between incident energy, dynamic compressive strength and the energy dissipation rate are 0.74 and 0.98, respectively. Theoretical analysis demonstrates that higher level of stress leads to greater energy released during unstable crack propagation, thus resulting in larger energy dissipation rate of coal under dynamic loads. At last, a semi-empirical energy dissipation model is proposed for describing the positive relationship between dissipated energy and stress.

• Advances in environmental research
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• 제5권1호
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• pp.1-18
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• 2016

Magnetic nano-based sorbents have been synthesized for the recovery of two rare earth elements (REE: Nd(III) and Yb(III)). The magnetic nano-based particles are synthesized by a one-pot hydrothermal procedure involving co-precipitation under thermal conditions of Fe(III) and Fe(II) salts in the presence of chitosan. The composite magnetic/chitosan material is crosslinked with epichlorohydrin and modified by grafting alanine and serine amine-acids. These materials are tested for the binding of Nd(III) (light REE) and Yb(III) (heavy REE) through the study of pH effect, sorption isotherms, uptake kinetics, metal desorption and sorbent recycling. Sorption isotherms are well fitted by the Langmuir equation: the maximum sorption capacities range between 9 and 18 mg REE $g^{-1}$ (at pH 5). The sorption mechanism is endothermic (positive value of ${\Delta}H^{\circ}$) and contributes to increase the randomness of the system (positive value of ${\Delta}S^{\circ}$). The fast uptake kinetics can be described by the pseudo-second order rate equation: the equilibrium is reached within 4 hours of contact. The sub-micron size of sorbent particles strongly reduces the contribution of resistance to intraparticle diffusion in the control of uptake kinetics. Metal desorption using acidified thiourea solutions allows maintaining sorption efficiency for at least four successive cycles with limited loss in sorption capacity.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.63.1-63
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• 2002