• Journal of the Korean earth science society
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• v.42 no.1
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• pp.39-54
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• 2021

Damyang Wetland, a riverine wetland, has been designated as the first wetland protection area in South Korea and is a candidate area for the Mudeungsan Area UNESCO Global Geopark. The Damyang Wetland area is the upstream part of the Yeongsan River and is now a relatively wide plain. To reconstruct the sedimentary environment around the Damyang Wetland, core samples were obtained, and sedimentary facies analysis, AMS and OSL age dataings, grain size, and geochemical analyses were carried out. In addition, comprehensive sedimentary environment changes were reconstructed using previous core data obtained from this wetland area. In the Yeongsan River upstream area, where the Damyang Wetland is located, fluvial terrace deposits formed during the late Pleistocene are distributed in an area relatively far from the river. As a gravel layer is widely distributed throughout the plains, Holocene sediments were likely deposited in a braided river environment when the sea level stabilized after the middle Holocene. Then, as the sedimentary environment changed from a braided river to a meandering river, the influx of sand-dominated sediments increased, and a floodplain environment was formed around the river. In addition, based on the pollen data, it is inferred that the climate was warm and humid around 6,000 years ago, with wetland deposits forming afterward. The the trench survey results of the river area around the Damyang Wetland show that a well-rounded gravel layer occurs in the lower part, covered by the sand layer. The Damyang Wetland was likely formed after the construction of Damyang Lake in the 1970s, as muddy sediments were deposited on the sand layer.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.633-648
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• 2022

Gravity data were analyzed to identify the cause of clustered seismicity that occurred intensively in Yeoncheon, located in the central part of the Korean Peninsula. Our analysis suggests that the En echelon faults developed in the northwest-southeast direction. In addition, in the eastern part of the Dongducheon Fault, it was interpreted that high-density lower bedrock intermittently lifts close to the surface due to vertical tectonic movement accompanied by a flower structure. The fracture zone of the Dongducheon Fault is estimated that the width is about 200 m, the depth is at least 5 km, and the density is about 15% lower than the adjacent rocks. It is analyzed that the shallow earthquakes that occurred within 5 km depth was concentrated along the low-density En echelon fault fracture zone developed between the high-density rocks intruding close to the surface. Therefore, the earthquakes can be interpreted as the result that the north-south stress caused by the dextral tectonic movement of the Dongducheon Fault activated the En echelon fault in the northwest-southeast direction.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.477-495
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• 2022

This study examined the sustainability of CO₂-rich water by analyzing the water level and water quality change pattern with the amount of its use in Angseong area, Chungju. The origin and supply of CO₂ component were discussed in consideration of ⁸⁷Sr/⁸⁶Sr ratio, occurrence of CO₂-rich fluid inclusions in nearby W-Mo deposits and other surrounding geological characteristics. According to the data from 1986 to 2017, the depth of the water level of CO₂-rich water was significantly lowered in the late period (2009-2015) than in the early period (1986-1992) of the development of hot spa wells, and the optimal yields for pumping tests also showed a tendency to gradual decrease. Concentrations of CO₂ component also decreased continuously in the later stages compared to the early stages of development, but it has been stable since 2012. It is inferred that the geological environment related to forming W-Mo quartz vein deposits (0.5×1.5×several km) around the study area are largely involved in the origin and supply of CO₂ component, and the supply of CO₂ component is not infinitely supplied from deep current magma activity. Rather, since it is finitely supplied from a restricted subsurface region formed in the past geological period, it is necessary to efficiently control its use in order to maintain the sustainability of CO₂-rich water in the study area.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.169-180
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• 2014

Surface geological and trench surveys and drilling exploration (total length, 1,100 m; 9 drill holes) were carried out to secure new Au ore bodies in the area($0.96km^2$) of Actosity gold field, where is located at the western Kuldjuktau mineralized district in the middle territory of Uzbekistan. Several Au ore bodies occurring as tabular or lens shapes with thickness of 0.5~35 m were newly discovered on the outcrops and extended to $N40{\sim}70^{\circ}\;W$ direction with dipping of $70{\sim}90^{\circ}$ SW or NE. Indicated ore resource of gold with Au grade of 0.25~3.52 mg/kg was newly estimated by 2,382 t(gold resource of 2.5 t) as a result of 9 drilling exploration in 2010~2012 from the Actosity gold field. Judging from the ore resources and Au grade of the Actosity gold field, economic potentiality of mining development seems to be low. Because of high possibility to secure new ore resources through more detailed exploration works from the Actosity area, the growth of econonic value will be expected by a mine of middle scale.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.17-27
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• 2024

This study investigated the fish fauna of Jeonjucheon and Samcheon Streams, flowing through the city of Jeonju, through surveys conducted at 10 sampling sites using kick net and cast net. The fish fauna collected included 10 families and 36 species, with a total of 2,064 individuals. Samcheon had 8 families and 30 species with 1,074 individuals, Jeonjucheon had 8 families and 26 species with 986 individuals. The dominant species was Zacco platypus with 1,202 individuals, and a total of 153 individuals of the subdominant were Pseudogobio esocinus. In Jeonjucheon Stream, a total of 567 individuals of the dominant species were collected as Z. platypus and 99 individuals of the subdominant species were collected as Pungtungia herzi, and there was no significant change in the stream environment except for the confluence site. Further expanded research covering the entire Jeonjucheon and Samcheon Streams region, accompanied by regular monitoring, is essential to record and understand fluctuations in fish fauna.

• Resources Recycling
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• v.17 no.1
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• pp.73-79
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• 2008

Along with the increased social infrastructures and reconstruction, the demand for aggregate, which is used in concrete, has rapidly increased. However, there are problems due to the exhaustion of natural aggregate resources, and strict restrictions. In this study, the possibility of using rapid chilled steel slag as a substitutive material of fine aggregate is determined from the property test and mechanical test for the concrete that is made with rapid chilled steel slag, which highly decreases the free CaO, the main problem of the steel slag.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.73-73
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• 2020

멀구슬나무 추출물이 식물 생장과 발달에 주는 영향을 알아보기 위해 멀구슬나무의 추출 공정 개발을 통한 추출 조건을 최적화, 항산화능, 페놀함량, 아미노산 함량을 분석 하였으며 식물에서 생장 증식률을 평가 하였다. 추출 공정을 표준화하기 위해 물과 에탄올 비율별 추출 및 수율을 확인한 결과 25% 에탄올 추출물에서 22%로 가장 높은 수율을 보였으며, 항산화능 평가 결과 DPPH, ABTS 모두 25% 에탄올 추출물이 다른 추출물과 비교 시 유사 하거나 높은 활성을 나타냈다. 또한 폴리페놀 함량 분석 시, 25% 에탄올 추출물에서 4.6 g/100g으로 가장 높은 함량을 보였다. 아미노산 함량 분석 시, 식물의 성장 성분인 glutamic acid와 식물의 수정을 돕는 성분인 prorine 함량이 높은 수치로 확인되었다. 이와 같은 결과를 토대로 멀구슬나무 25% 에탄올 추출물의 식물 생장능을 확인하기 위해 pot 시험을 수행하였다. 을 이용한 식물 생장 시험을 진행하였다. 그 결과, 멀구슬나무 추출물을 처리한 군이 하지 않은 control 군에 비해 입면적과 높이가 증가 하였으며 새순의 수가 더 증가하여 식물 생장능을 확인 하였다.

• Economic and Environmental Geology
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• v.37 no.4
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• pp.383-389
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• 2004

Understanding flow pattern of water and solute in subsurface is essential for the reduction and prevention of contamination of soil and groundwater and for the investigation and remediation of contaminated site. The objective of this study is to examine the infiltration pattern in a soil developed from the Jurassic granite using (Brilliant Blue FCF $C_{37}H_{34}N_{2}Na_{2}O_{9}S_{3}$), the nonfluorescent and nontoxic food dye. All image processing was conducted using geographic image processing software, ER Mapper, Version 6.2. The dye coverage was determined by counting the stained pixels in the photographs (80${\times}$80cm, 80TEX>${\times}$5cm) for the vertical and horizontal view. A homogeneous matrix flow occurred in the A horizon with weak, medium granular structure and fingering at the interface of finer-textured A horizon and coarser-textured C horizon. Pegmatitic vein originated from the granite and plant root in C horizon induced preferential flow.

• Economic and Environmental Geology
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• v.37 no.3
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• pp.269-276
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• 2004

The Indonesian Archipelago is located in the southern tip of the Eurasian plate. The diverse subduction system of the Indonesia region records interactions between three megaplates (Eurasian, Indian-Australian, and Pacific plates) and many smaller plates. The geology of Indonesian Archipelago is characterized by many factors such as subduction zone complexes, magmatic arc rocks associated with plate tectonics, the arc granite and volcanic rocks, and the related metamorphic rocks. The base-metal deposits of Indonesia have a great effect on petrochemical character of parent rocks and geotectonic environments. The base-metal deposits can be classified into four types as hosted by felsic-intermediate intrusive rocks, hosted by ultramafic rocks, hosted by volcanic rocks, and hosted by sedimentary rocks. The gold deposits are divided into three types: epithermal gold deposits, porphyry copper associated gold deposits, and alluvial gold deposits. Especially, Indonesian island uc, with its numerous plates tectonic, has an high potential for epithermal gold deposits. Indonesia with many old and present subduction zones and sub-aerial calcalkaline volcanic rocks is a very promising country for epithermal gold mineralization.

• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.443-468
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• 2020

Broad effects of fuel-transition in all type of ground transportation have occurred with the help of the advances in electric vehicle (EV) technologies and the increases in EV supply. This research estimates the economic benefit of air environmental improvements, which results from the fuel-transition of high-mileage business cars(taxies) in metropolis. If we consider power production sector for EV operation, some air pollutants will be produced. In this respect, this research takes both the mixture of power sources in power production level and the driving pattern of business cars into account when investigating the economic benefit in air environment resulted from the fuel-transition of business cars(taxies). According to our results, the business cars' fuel transition from LPG to electricity brings about 21.5￦/km (8.6million won/year) of economic benefit in air environment. These results emphasize the necessity and appropriateness of public polices for expanding power production with renewable energies and facilitating EV distribution.