• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.102-121
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• 2012

The purpose of this study is to verify homoteneity of soil and earthenwares and identify firing temperature of earthenwares excavated from Yeoncheon Hapsuri: two earthenwares of the New Stone Age(YCP-1, YCP-2); two of the Bronze Age(YCP-3, YCP-4); and four of the Three States Age(YCP-4~8). The comparative analysis of soil (YCRM) and the earthenwares displays that soil geochemical patterns were similar to YCP-1, YCP-3, YCP-5, YCP-6, YCP-7 and YCP-8. On the other hand, YCP-2 and YCP-4 did not show the similarity to the one of soil because they had been enriched with MgO by contained talc and chlorite. Based on the absorption rate, specific gravity, structural characteristics and XRD analysis, firing temperature has been estimated: for YCP-7 and YCP-8 was $870^{\circ}C$ or over; for YCP-2 and YCP-4 $800^{\circ}C$ or below; and for YCP-1, YCP-3, YCP-5 and YCP-6 between 800 and $870^{\circ}C$. Mineralogical analysis displays that the geochemical pattern of the soil is coincide with the one around Yeoncheon Hapsuri site, which also shows similarity to the one of earthenwares. Such result persuades that the excavated earthenwares were produced with the soils within the precinct of the archaeological sites.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.601-604
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• 2003

방사성폐기물 처분 연구의 일환으로 화강암지역내 500m 심도의 심부시추공이 착정되었으며, 다중패커시스템이 설치되어 장기적으로 심도별 지하수의 수리 및 화학특성이 모니터링 되고 있다. 지하수 수두값의 심도별 특성은 천부에서 심도 250m까지는 대체로 감소하는 경향을 보이며 250m이하에서 500m 심도까지는 증가하는 경향을 보여준다. 각 심도구간에서의 지하수 수두값은 장기적으로 일정한 값을 보여주지만, 장마기간동안 집중적으로 모니터링된 결과에 따르면 심도 370m 상부에서는 지하수 함양변화에 따라 지하수 수두가 변화되는 반면, 심부구간에서는 지하수 함양변화에 대하여 영향을 받지 않음을 보여준다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.442-446
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• 2003

이 연구는 제주도 한림 지역에서 지하수의 수질과 오염의 특성을 규명하고자 시행되었다. 2002년 8월과 11월에 걸쳐 34개 지점에서 지하수 시료를 채취하였고, 이를 분석하여 지하수의 수질을 유형별로 분류하였다. 연구지역은 주로 (Na,Mg)-HCO$_3$ 유형이 나타나며, 일부 지점에서는 Mg-(HCO$_3$+Cl), (Ca,Mg)-HCO$_3$ 유형 등이 나타난다. 이는 지하수의 유동 경로를 따라 서로 다른 수리지화학적 반응이 일어나며, 지표 오염물질의 유입 등이 지하수의 수질에 영향을 미치고 있음을 지시한다. 질산성 질소의 경우, 국내 먹는물 수질기준치 10 mg/L를 초과한 시료는 전체 시료의 8월 조사에서 약 32%, 11월 조사에서 약 27% 이었고, 공간적 분포 특성은 비교적 낮은 고도 150m 이하의 저지대에서 채취한 시료에서 주로 나타났다. 인위적인 오염물질의 유입 가능성이 있는 지점은 전체 시료의 79.4% 이었다.

• The Microorganisms and Industry
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• v.15 no.2
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• pp.2-7
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• 1989

Waksman과 Heinrich(1943)에 의해 Streptomyces속이 기술되고 actinomycin, streptomycin등의 많은 항생물질이 발견되면서 방선균(actinomycetes)은 산업적으로 중요한 미생물이 되어 왔으며, 근래에는 항생물질 뿐만 아니라 효소, 효소저해제, 면역조절물질 등 소위 생리활성물질(bioactive compound)의 생산균으로서 주목을 받고 있다. 그러나 지금까지 대부분의 스크리닝이나 연구의 대상은 주로 중성 pH에서 잘 자라는 호중성 방선균(neutrophilic actionmycetes)이었지만 산성이나 알칼리성 토양, 고온, 고열, 고압 등과 같은 특수환경에서 분리된 균주나 희귀 방선균(rare actinomyces)에 대한 관심도 점점 높아지고 있다. 산성 토양에서 분리된 방선균에 관한 연구는 Jensen(1928)의 연구로부터 시작하였지만 Lonsdale(1985)이 침엽수림, 산성탄광 등에서 분리된 방선균을 수리분류할 때까지 활발하게 이루어지지 못하였다. 본 고에서는 호산성 방선균위 분포, 생리적 특성, 수리분류학적 연구, 화학적 분류(chemotaxonomy), 산업적 응용가능성 등을 살펴보고자 한다.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.27-38
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• 2018

Groundwaters in different rock types (Mesozoic granite, Precambrian gneiss, and schist) of Ganghwa island, Incheon City were characterized by using naturally occurring radioactive materials (NORM) and hydrogeochemical constituents. For the study, groundwater samples from 69 wells had been collected over eight years. Statistical methods were applied to relate hydrogeochemical components and NORM in the groundwater samples. The groundwater samples belonged to $Ca(Na)-HCO_3$ types. The uranium concentrations in three groundwater samples exceeded 30 ug/L of United States Environmental Protection Agency (US EPA) maximum contaminant level (MCL). The radon concentrations in 28 groundwater samples exceeded 4,000 pCi/L (picocuries per Liter) of US EPA alternative maximum contaminant level (AMCL). Gross-alpha in all the groundwater samples did not exceed 15 pCi/L of US EPA MCL. The average concentrations of uranium and radon in groundwater were the highest in granite area, and then gneiss, schist areas in order. In schist area, the correlation coefficient (R) between radon and $HCO_3$ is -0.40 and R between uranium and $SO_4$ is 0.54. In gneiss area, the R between radon and uranium is 0.55 and the R between uranium and $SO_4$ is 0.41. According to factor analysis, each geological area shows different chemical characteristics. The statistical analysis of whole groundwater resulted in nearly no significant relationship among uranium, radon and chemical constituents. Subsequently, more detailed studies on hydrogeological, geochemical, and geological characteristics related to NORM are required to better understand the behavior and fate of NORM.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.533-545
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• 2015

Spatial and seasonal variations in hydrogeochemical characteristics and the factors affecting the deterioration in quality of shallow portable groundwater in an agricultural area are examined. The aquifer consists of (from the surface to depth) agricultural soil, weathered soil, weathered rock, and bedrock. The geochemical signatures of the shallow groundwater are mostly affected by the NO₃⁻ and Cl⁻ contaminants that show a gradual downward increase in concentration from the upper area, due to the irregular distribution of contamination sources. The concentrations of the major cations do not varied with the elapsed time and the NO₃⁻ and Cl⁻ ions, when compared with concentrations in background groundwater, increase gradually with the distance from the upper area. This result suggests that the water quality in shallow groundwater deteriorates due to contaminant sources at the surface. The contaminations of the major contaminants in groundwater show a positive linear relationship with electrical conductivity, indicating the deterioration in water quality is related to the effects of the contaminants. The relationships between contaminant concentrations, as inferred from the ternary plots, show the contaminant concentrations in organic fertilizer are positively related to concentrations of NO₃⁻, Cl⁻, and SO₄²⁻ ions in the shallow portable groundwaters, which means the fertilizer is the main contaminant source. The results also show that the deterioration in shallow groundwater quality is caused mainly by NO₃⁻ and Cl⁻ derived from organic fertilizer with additional SO₄²⁻ contaminant from livestock wastes. Even though the concentrations of the contaminants within the shallow groundwaters and the contaminant sources are largely variable, it is useful to consider the ratio of contaminant concentrations and the relationship between contaminants in groundwater samples and in the contaminant source when analyzing deterioration in water quality.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.495-508
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• 2019

We measured the concentrations of natural radionuclides (uranium and radon) and major elements in groundwater collected from forty wells located in Wonju area to investigate the hydrochemistry and the occurrence of these radionuclides. The range of electrical conductivity (EC) value in the study area was 73~400 μS/cm. In addition to the increase of EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from 0.06~50.5 ㎍/L (median value, 1.55 ㎍/L) and radon concentrations ranged from 67~8,410 pCi/L (median value, 1,915 pCi/L). Uranium concentrations in 3 well, 7.5% of the samples, exceeded 30 ㎍/L, the maximum contaminant level (MCL) proposed by the US Environmental Protection Agency (EPA), based on the chemical toxicity of uranium. Radon concentrations in 9 wells, 22.5% of the samples, and 1 well, 2.2% of the samples, exceeded 4,000 pCi/L (AMCL of the US EPA) and 8,100 pCi/L (Finland's guideline level), respectively. Concentrations of uranium and radon related to geology of the study area showd the highest values in groundwater of the biotite granite area. Uranium and radon contents in the groundwater are comparatively low compared to those in other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• Economic and Environmental Geology
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• v.51 no.6
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• pp.553-566
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• 2018

The occurrence of natural radionuclides like uranium and radon in groundwater was hydrochemically examined based on 40 well groundwaters in Mungyeong area. The range of electrical conductivity (EC) value in the study area was $68{\sim}574{\mu}S/cm$. In addition to the increase of EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from $0.03{\sim}169{\mu}g/L$ (median value, $0.82{\mu}g/L$) and radon concentrations ranged from 70~30,700 pCi/L (median value, 955 pCi/L). Only 1 out of 40 wells (2.5%) showed uranium concentration exceeding the maximum contaminant level (MCL; $30{\mu}g/L$) proposed by the US Environmental Protection Agency (EPA). Radon concentrations of eight wells (20%) exceeded AMCL(Alternative maximum contaminant level) of the US EPA (4,000 pCi/L). Four out of those eight wells even exceeded Finland's guideline level (8,100 pCi/L). When concentrations of uranium and radon were investigated in terms of geology, the highest values are generally associated with granite. The uranium and radon levels observed in this study are low in comparison to those of other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• The Journal of Engineering Geology
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• v.14 no.4 s.41
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• pp.469-485
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• 2004

The purpose of this study is to investigate the hydrochemical characteristics of groundwater in the Umsung area, and to elucidate the effect of host rock type, well depth and mineralization zone on the groundwater chemistry. The geology of the study area consists of Jurassic granite and Cretaceous sedimentary rocks, which are bounded by a fault. Most of shallow groundwaters exploited in the Jurassic granite area are used for agricultural purpose, whereas the deep groundwaters in the Cretaceous sedimentary rocks are used for a drinking water. The shallow groundwater shows weak acidic pH, the electrical conductivity ranging from $142\;to\;903\;{\mu}S/cm$, and the chemical type of $Ca-HCO_3\;to\;Ca-Cl(SO_4,\;NO_3)$. A few of shallow groundwaters are contaminated by nitrate, and show high concentration of Fe, Mn and Zn, that reflects the effect of a mineralization zone. The deep groundwater shows neutral to weak alkaline pH, higher electrical conductivity than that of shallow groundwater, and the chemical type of $Ca-HCO_3$. The seepage water from the abandoned mines does not have the characteristics such as acidic pH, high concentration of heavy metals and high sulfate content. The hydrogen and oxygen isotopes of groundwater indicates an altitude effect of the recharge area between deep groundwater and shallow groundwater. In conclusion, the chemical composition of groundwater complicately reflects the effects of their host rocks, well depth, agricultural activity and mineralization zone in the study area.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.255-269
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• 2001

The geochemical studies on groundwater in the borehole, which is straddled by multi-packer (MP) system, were carried out from a volcanic terrain in the Yeosu area. The pH of groundwater collected from selected sections in the MP-installed borehole is much higher (up to 9.6) than that of the borehole groundwater (7.0-7.9) collected using conventional pumping technique. Hydrochemistry shows that the groundwater has a typical chemical change with increasing sampling depth, suggesting that the groundwater is evolved through water-rock interaction along the fracture-controlled flow paths. The groundwater from the deeper part (138-175 m below the surface) in borehole KI is characterized by the Ca-C11 type with high Ca (up to 160 mg/L) and Cl (up to 293 mg/L) contents, probably reflecting seawater intrusion. The groundwater also has high sodium and sulfate contents compared to the waters from other boreholes. These observed groundwater chemistry is explained by the cation exchange, sulfide oxidation, and mixing process with seawater along the flow path.