• Journal of the military operations research society of Korea
• /
• v.16 no.1
• /
• pp.94-112
• /
• 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
• /
• 2001.10a
• /
• pp.28.4-28
• /
• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.8 no.2
• /
• pp.254-263
• /
• 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
• /
• v.44 no.1
• /
• pp.41-47
• /
• 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.)

• Economic and Environmental Geology
• /
• v.42 no.6
• /
• pp.619-626
• /
• 2009

The price fluctuation of minerals are commonly occurred through the change of market condition, and the redevelopment of closed mines are usually happened if commercial requirement can be satisfied. After 2003, as the price of most of metals increased very rapidly, Korea government tried to find the possibility of reopening for some closed metal mines. The purpose of this article is to suggest the proper ways how effectively to regulate the mine pollution concerning the redevelopment of closed mines. For this work, with the recent price trends of metals and reopening possibility of closed metal mines in Korea were reviewed. And analysing the problems of regulations for the mine development permission and mine pollution control and reclamation process of Korea, several amendments of environmental and mining regulation regimes for redevelopment of closed mines were proposed.

• The Journal of Engineering Geology
• /
• v.18 no.3
• /
• pp.297-302
• /
• 2008

The main reason of the pollution caused by soils and tailings located at discussed mines is heavy metals and AMD(acid mine drainage). Human health is affected by these pollutants which are spreaded from the abandoned mines. In this study, we try a mathematical approach to predict the pollution level of heavy metals caused by the surrounding soils of abandoned mines. The new approach is established with the correlation between the distance and pH, ORP. The change of pH and ORP can be described by the rate of initial values to experimental values. We demonstrate a realistic possibility of the mathematical approach to assess an environmental impact from disused mines cause the rate range is 0.95 to 1.03 for 60 days. Therefore our proposed approach will be useful as a few promising method for the management of heavy metals in many mines.

• Journal of Food Hygiene and Safety
• /
• v.17 no.4
• /
• pp.178-182
• /
• 2002

This study was conducted to estimate the status of heavy metal contamination in agricultural products (n = 280), soils (n = 280), and irrigation waters (n = 48) in abandoned mines & normal farm lands (n = 8). The samples were digested with acids, then analyzed fur the contents of lead (Pb), cadmium (Cd), copper (Cu), mercury (Hg), arsenic (As) and chrome (Cr) by an inductively coupled plasma spectrometer (ICP) and graphite- atomic absorption spectrophotometer (AAS). The contents of Hg were determined using a mercury analyzer. Abandoned mines had soils with higher contents of heavy metals except Cr and irrigation waters with higher heavy metals except Hg, compared to those of normal farmlands. The contents of heavy metals in agriculture products varied depending types of products. Agricultural products in abandoned mines generally showed with higher contents of heavy metals except Cu, compared to those of normal farmlands. There was no significant relationship in heavy metal contents between agricultural products and soils (p > 0.05). It is suggested that heavy metals of agricultural products and soils in abandoned mines should be continuously monitored.

• Geomechanics and Engineering
• /
• v.11 no.5
• /
• pp.657-670
• /
• 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
• /
• v.5 no.1
• /
• pp.1-18
• /
• 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.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2002.10a
• /
• pp.63.1-63
• /
• 2002