• Economic and Environmental Geology
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• v.44 no.3
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• pp.193-201
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• 2011

The Geopung Cu deposit consists of two subparallel quartz veins that till the NE-trending fissures in Triassic Cheongsan granite. The quartz veins occur mainly massive with partially cavity and breccia. They can be followed along strike for about 500 m and varies in thickness from 0.2 to 2.2 m. Based on the mineralogy and paragenesis of veins, mineralization of quartz veins can be divided into hypogene and supergene stages. Hypogene stage is associated with hydrothermal alteration minerals such as sericite, pyrite, quartz, chlorite, clay minerals and sulfides such as pyrite, arsenopyrite, pyrrhotite, marcasite, sphalerite, stannite, chalcopyrite and galena. Supergene stage is composed of geothite. Fluid inclusion data from quartz indicate that homogenization temperatures and salinity of hypogene stage range from 163 to $356^{\circ}C$ and from 0.2 to 7.2 wt.% eq. NaCl, respectively. They suggest that ore forming fluids were progressively cooled and diluted from mixing with meteoric water. Sulfur (${\delta}^{34}S$: 4.3~9.2‰) isotope composition indicates that ore sulfur was derived from mainly magmatic source although there is a partial derivation from the host rocks. The calculated oxygen (${\delta}^{18}O$: 0.9~4.0‰) and hydrogen (${\delta}D$: -86~-69‰) isotope compositions suggest that magmatic and meteoric ore fluids were equally important for the formation of the Geopung Cu deposit and then overlapped to some degree with another type of meteoric water during mineralization.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.435-444
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• 2009

In situ stabilization of heavy metals through adsorption onto indigenous bacterial biofilm developed on soil particles was investigated. Biofilms were developed in soil columns by supply of various carbon sources such as acetate, lactate and glucose. During development of biofilms, acetate, lactate, and glucose solutions were flew out from the soil columns with volume ratios of 98.5%, 97.3%, and 94.7%, respectively, when compared with soil column supplied with deionized water. Decrease in effluent amounts through the soil columns amended with carbon sources over time indicated the formation of biofilms resulting in decrease of soil porosity. Solutions of Cd, Cr(VI), Cu, Pb, and Zn were injected into the biofilms supported on soil particles in the columns, and the dissolved heavy metals in effluents were determined. Concentrations of dissolved Cd, Cr(VI), Cu, and Zn in the effluents through biofilm columns were lower than those of control column supplied with deionized water. The result was likely due to enhanced adsorption of the metals onto biofilms. Efficiency of metal removal by biofilms depended on the type of carbon sources supplied. The enhanced removal of dissolved heavy metals by bacterial biofilms in this study may be effectively applied to technical development of in situ stabilization of heavy metals in natural soil formation contaminated with heavy metals.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.1-16
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• 1989

Electrum-galena-sphalerite mineralization of the Yangpyeong-Weonju Au-Ag area was deposited in three stages of quartz and calcite veins which fill fault breccia zones. Fluid inclusion and stable isotope data show that ore mineralization was deposited at temperatures between $260^{\circ}C$ and $180^{\circ}C$ from fluids with salinities between 8.9 and 2.9 equivalent weight percent NaCl. Evidence of boiling indicates pressures of <50 bars, corresponding to depths of 220 to 550 m, respectively, assuming lithostatic and hydrostatic loads. Au-Ag deposition was likely a result of bolling coupled with cooling. Within stages I and II there is an apparent increase in ${\delta}^{34}S$ values of $H_2S$ with paragenetic time ; early -1.4~2.7‰ to later 6.6-9.2‰. The progressively heavier $H_2S$ values can be generated through isotopic re-equilibration in the ore fluid following removal of $H_2S$ by boiling or precipitation of sulfides. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values. Comparison of these values with those of other Korean Au-Ag deposits reveals a relationship between depth and degree of water-rock interaction. All investigated Korean Jurassic and Cretaceous gold-silver-bearing deposits have fluids which are dominantly evolved, meteoric water, but on1y deeper systems (${\geq}1.25km$) are exclusively gold-rich.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.377-382
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• 2007

Porous mineral coating have been fabricated and applied for basic research on their slow release action to a fertilizer. Feldspar was selected as raw mineral for the coating and two different particle sizes of powder were prepared. Slow-release action was estimated by using a potassium sulfate fertilizer. Spherical pellets were prepared with a pan-type pelletizer and then screened into sizes ranging 1.4 to 2.35mm. While the fertilizer pellets were rotated in the pelletizer again, the feldspar powder and 0.5% polyvinyl alcohol solution were simultaneously sprayed on the pellets. The fertilizer pellets coated with feldspar powder were fabricated. The pellets were heated to increase their strength and screened to sort by coating thickness. Potassium releasing tests were conducted for 40 days and the performance for slow-release action was estimated as functions of the heating temperature, coating thickness and raw mineral powder size. The Burst effect caused high initial releasing rate. Releasing kinetics was proportional to concentration of potassium in pellets. The pellet that was fabricated with $27.4{\mu}m$-sized feldspar and heated at $1050^{\circ}C$ showed a releasing rate of 43% on the 40th day.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.582-594
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• 2018

In this study, the vertical and horizontal flow wetlands were combined in series to create conditions for flow in the exhalation and anaerobic state with the aim of monitoring the variability and reduction of dissolved organic matterin the bio-reactive artificial wetlands, and the performance assessment was conducted as acrylic reaction groups by designing artificial wetlands that filled the functionalresiduals. In case of artificial wetlands in vertical and horizontal planes, the concentration of dissolved oxygen (DO) in the reaction tank was measured as 2.7 mg/L in the vertical flow wetlands under exhalation, and N.D. in the horizontal flow artificial wetlands under anaerobic conditions. The test was carried out by changing the operation time to 140 min, 80 min, and 60 min. The test was conducted with the same natural operation time of 20 min depending on the operation time. All hours of operation were shown to be due to microbial activity. In 3D-EEM, it was found that the longer the driving time was taken, the more reduction the organic compounds in the areas of insoluble human resources, III and V. Further research on the mechanism analysis of future reduction effects is expected to be carried out, but the findings are expected to contribute to the development of technologies for reducing obfuscated substances using artificial wetlands in the future.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.85-85
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• 2019

가는잎향유[Elsholtzia angustifolia (Loes.) Kitag.]는 꽃이 원줄기와 가지 끝에 조밀하고 아름답게 달리며, 전초에 함유된 정유성분의 향이 우수하여 관상 및 약용으로 이용되고 있다. 이에 본 연구는 관상소재로 이용가능한 가는잎향유의 분화 재배기술을 확립하기 위해 2018년 7월 2일에 유묘(4월 3일~5월 31일 육묘)를 포트에 정식하여 10월 15일까지 수행하였다. 대조구는 플라스틱 화분 10호에 원예상토를 충진한 다음 200구 트레이에 셀당 4립 파종하여 생산된 유묘를 정식하여 이용하였다. 기비처리는 싱싱코트를 0, 10 및 20알로 처리하였고, 추비처리는 정식 후 4주 간격으로 hyponex (4-6-6)를 0, 1000 및 $2000mg{\cdot}L-1$로 3회 엽면시비 하였다. 차광정도 실험은 0, 55 및 75%로 광량을 달리하여 수행하였다. 왜화제는 diniconazole과 daminozide를 각 0, 1000 및 $2000mg{\cdot}L-1$로 정식 후 4주차에 처리하였다. 연구의 결과, 기비와 추비 처리는 무처리와 비교하여 생육에 큰 차이가 없었으나, 절간장은 처리량이 증가할수록 억제되었으며, 처리시 무처리에 비해 유의적으로 감소하였다. 측지수 및 엽수는 기비 처리에 따른 큰 차이가 없었으며, 추비는 측지수와 엽수가 많아지는 경향이었다. 한편, 기비와 추비 처리는 개화율을 비교적 감소시키는 결과를 보였다. 차광정도가 증가할수록 초장, 절간장, 경직경, 화서수, 화서장이 감소하는 경향이 나타났으며, 무차광과 차광처리 간 측지수와 엽수는 유의적인 차이가 나타나지 않았다. 왜화제 처리는 무처리와 비교하여 절간장을 감소시켰다. Daminozide 처리시 측지수와 엽수는 무처리에 비해 증가하였으나 유의적인 차이는 없었고, 지상부의 생체중은 엽수와 측지수에 비례하여 무거워지는 결과를 보였다. 또한, $2000mg{\cdot}L-1$ 농도 처리시 개화율이 100%에 도달하였다. Diniconazole 처리는 무처리와 비교하여 큰 차이가 없었다. 따라서, 가는잎향유를 분화재배를 하기 위해서는 기비와 추비는 처리하지 않고, 무차광 조건에서 재배하는 것이 좋다. 또한, 왜화제는 daminozide $2000mg{\cdot}L-1$로 처리하는 것이 측지수, 엽수 및 개화율이 우수한 결과를 보여 분화 재배에 적합할 것으로 판단된다.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.219-223
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• 2011

The characteristics of SOx emission were investigated using SM (India) coal and Berau, C&A (Austria) coal. Experiments were performed in two different ways. In the first type of experiment, the temperature in the furnace was increased and the, samples were combusted at the ignition temperature after filling the furnace with coal. The second experimental method was to add the coal to after maintaining a constant temperature. The results demonstrated that SOx emission from coal combustion depended upon the sulfur content. In the case of Berau coal and C&A coal, an enhancement of combustibility which was accomplished by increasing the combustion temperature, an increase in airflow and decrease in particle size of coals tended to increase $SO_2$ generation. Conversely, in the case of SM coal, the concentration of $SO_2$ tended to decrease, because the high contents of $Fe_2O_3$ in the ashes increased the oxidation power of coal itself, which oxidized $SO_2$ into $SO_3$. In the case of C&A coal, the $SO_2$ peak was only observed twice. This was thought to be caused by the thermal transfer rate from the surface to the interior of the coal.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.753-765
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• 2021

The Dongwon Au-Ag deposit is located within the Paleozoic Taebaeksan province, Okcheon belt. Mineral paragenesis can be divided into two stages (stage I, ore-bearing quartz veins; stage II, barren carbonate veins) by major tectonic fracturing. Stage I, at which the precipitation of major ore minerals occurred, is further divided into three substages(early, middle and late) with paragenetic time based on minor fractures and discernible mineral assemblages: early, marked by deposition of pyrite with minor magnetite, pyrrhotite and arsenopyrite; middle, characterized by introduction of electrum and base-metal sulfides with minor sulfosalts; late, marked by argentite, Cu-As (and/or Sb) and Ag-Sb sulfosalts with base-metal sulfides. Fluid inclusion data show that stage I ore mineralization was deposited between initial high temperatures (≥430℃) and later lower temperatures (≤230℃) from fluids with salinities between 6.0 to 0.4 wt. percent equiv. NaCl. The relationship of salinity and homogenization temperature suggest that ore mineralization at Dongwon was deposited mainly due to fluid boiling, cooling and dilution via influx of cooler, more dilute meteoric waters. Changes in stage I vein mineralogy reflect decreasing temperature and fugacity of sulfur by evolution of the Dongwon hydrothermal system with increasing paragenetic time. The Dongwon deposit may represents a Korean-type and/or Au-Ag type mesothermal/epithermal gold-silver deposit.

• Analytical Science and Technology
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• v.21 no.6
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• pp.543-552
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• 2008

This paper described the relatively sensitive and simultaneous analytical method for 3-monochloropropane-1,2-diol (3-MCDP, $C_3H_7ClO_2$, MW. 110) as well as 1,3-dichloropropan-2-ol (1,3-DCP, $C_3H_6Cl_2O$, MW. 128) in various foods. Food samples were homogenized in 5M NaCl solution, mixed with aluminum oxide and eluted with dichloromethane. The extracted chloropropanols were concentrated by rotary evaporator and $N_2$ blow serially were derivatized with HFBA (Heptafluorobutyric anhydride, $C_8F_{14}O_3$, MW. 410) and were determined by GC/MS using isotope dilution method. The characteristic molecular ions at m/z 253, 275, 289, 291, and 453 for HFBA derivatives of 3-MCPD (MW. 502) and 110, 275, and 277 for HFBA derivatives of 1,3-DCP (MW. 325) were chosen in selected ion mode. The method validation data showed sufficiently good properties of LOD (0.003 mg/kg), LOQ (0.010 mg/kg), linearity ($R^2{\geq}0.999$ at 0.010~1.000 mg/kg), and recovery rate (${\approx}97%$). The levels of chloropropanols in soy sauce, sauces, processed meat products, fishery products, and seasonings (n=56/157) determined by the presented method were 0.0~0.3 mg/kg.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.23-23
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• 2020

털부처꽃(Lythrum salicaria L.)은 예로부터 발효해서 술로 마시고, 잎은 채소로 식용하며, 식중독 치료 및 설사를 멈추게 하는 효과가 있는 것으로 알려져 있다. 한국, 중국, 아프리카, 유럽, 북아메리카 등의 습한 지역에 분포하며, 7~8월에 취산꽃차례로 붉은 자주색의 꽃이 핀다. 본 연구는 털부처꽃을 지피용 소재로 개발하기 위한 최적의 재배기술을 확립하기 위해 수행되었다. 재배방법의 확립을 위하여 2019년 4월 27일에 파종하여 생산된 유묘를 7월 4일에 정식하여 9월 24일까지 12주 동안 재배하였다. 공통 조건은 3치 비닐 포트에 원예상토를 충진하고, 200구 트레이에 셀당 1립씩 파종하여 생산된 1셀 묘를 정식하였으며, 추비, 차광, 적심 등은 처리하지 않았다. 추비 실험은 hyponex 하이그레이드(N-P-K, 7-10-6)를 0, 500, 1000, 2000mg·L^-1를 4주간 간격으로 총 3회 엽면시비 하였다. 차광 정도 실험은 0, 35, 55, 75% 차광막을 이용하였으며, 적심은 무적심과 4주차에 1회 적심처리 하였다. 연구의 결과, 털부처꽃은 추비 농도가 증가할수록, 생육이 감소하는 결과를 보였다. 차광처리 별로는 무차광 조건에서 생육이 가장 왕성한 결과를 보였고, 광량의 부족은 전반적으로 생육을 억제하는 경향이었다. 적심 처리는 줄기 신장을 크게 억제하였으며, 측지수를 증가시키는 결과를 보였다. 엽수는 무처리와 비교하였을 때 유의적인 차이가 없는 것으로 확인되었다. 따라서 털부처꽃은 적심을 하는 것이 효과적인 것을 알 수 있었으며, 적심 시기에 관한 추가적인 연구가 필요할 것으로 생각된다. 결론적으로 추비처리는 털부처꽃의 생육에 부정적인 영향을 주므로 처리하지 않고, 무차광 조건에서 재배하는 것이 전반적인 생육에 유리하였다. 또한 도장이 잘되는 식물임으로 적심처리하는 것이 좋을 것으로 판단된다.