• Proceedings of the Korean Quaternary Association Conference
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• 2004.06a
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• pp.46-46
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• 2004

Van Mijenfjorden은 스발바드 군도의 Spitsbergen 서부에 위치하는 두 번째로 큰 피오르드로 온난하고 염분도가 높은 북대서양의 표층수가 북극해로 유입되는 Gateway에 위치하기 때문에 전지구적이며 지역적인 기후변화의 영향을 받는 지역이다. 1999년 IMAGES 프로그램의 일환으로 프랑스 탐사선인 'R/V Marion Dufresne'을 이용하여 북극해의 스발바드 군도에 위치하는 Van Mijenfjorden (77$^{\circ}$ 46.87'N and 15$^{\circ}$ 17.81'E)에서 약 18m의 빙ㆍ해양 퇴적물 코아(MD99-2305)를 시추하여 마지막 최대 빙하기 이후의 고환경변화를 연구하였다. AMS 14C 연대 측정에 의하면 diamicton 층인 하부 2m를 제외한 16m의 퇴적층은 지난 12cal. ka BP경에 피오르드에 존재하던 조수빙하(tidewater glacier)가 해빙되기 시작한 이후에 퇴적되었다. 특히 유기지화학 자료와 부유성과 저서성 유공충의 산출양상 그리고 저서성 유공충인 C. reniforme의 산소ㆍ탄소 안정동위원소 비에 의하면 코아 MD99-2305에는 Van Mijenfjorden에서 홀로세 동안에 일어난 퇴적환경변화를 잘 기록하고 있다. 특히 홀로세 동안에 피오르드내의 퇴적환경 변화는 조수빙하의 확장과 후퇴와 밀접한 관계가 있으며, 유기물의 탄소동위원소(13Corg) 비는 -24에서 -22$\textperthousand$ 값의 변화를 보인다. 이는 Van Mijenfjorden 퇴적물에 공급된 유기물은 육상과 해양기원이 혼합되어 퇴적되었음을 지시한다. 지난 12 cal. ka BP 이후 13Corg 값이 뚜렷하게 변하는 것은 Van Mijenfiorden에서 조수빙하의 변동과 표층수에서의 생산력의 변화를 강하게 반영한다. 강하게 반영한다.53%가 이공계 출신, 100대 기업 CEO의 38.4%가 이공계 출신, 대입수능시험에서 자연계 지원비율이 감소 -40.1%('99)\$\longrightarrow$34.7%('00)\$\longrightarrow$29.4%('01)\$\longrightarrow$26.9%('02)\$\longrightarrow$30.3%('03)\$\longrightarrow$31.5%\$\longrightarrow$'04)필요성, 효과적인 운전자 교육 정책 등이 그것이다. 자동차 긴급 피난 차선은 유용한 시설로 여러곳에서 그 기능이 발휘되고 있으므로 많은 고속도로 관계자들은 설계, 시공 및 유지 관리 측면에서 유의해야 할 것이다.미세조직을 광학현미경으로 압출방향에 평행한 방향과 수직방향으로 관찰하였고, 열간 압출재 이방성을 검토하기 위하여 X선 회절분석을 실실하여 결정방위를 확인하였다. 전기 비저항 및 Seebeck 계수 측정을 위하여 각각 2$\times$2$\times$10$mm^3$ 그리고 5$\times$5$\times$10TEX>$mm^3$ 크기의 시편을 준비하였다.준비하였다.전류를 구성하는 주요 입자의 에너지 영역(75~l13keV)에서 가장 높은(0.80) 상관계수를 기록했다. 넷째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가 있음을 시사한다.se that were all low in two aspects, named "the Nonsignificant group". And the issues were

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.37-43
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• 1998

Chemical components of water, chemical and isotopic compositions of extractable gases were analyzed to characterize the properties of the natural gases which are dissolved in ground water in the Pohang area. Amount of total extracted gases ranges from 27 ml/l to 50.1 ml/l. Hydrocarbon gases are composed of methane ($27{\~}376,420 ppm$) and ethane ($19{\~}127 ppm$). Amount of total hydrocarbon gases is related to the lithology and geological factors around the reservoir. Quantity of hydrocarbon gases tends to increase in the Tertiary reservoirs and in the reservoirs where the Tertiary formations are thick enough. According to the relationship between hydrocarbon gases and total solids in the ground water, it is believed that the hydrocarbon gases were dissolved in the Tertiary formation water. Based on the methane content ($>99.9\%$) and isotopic composition (${\delta}C^{13};-73.1\%_{\circ}{\~}-43.22\%_{\circ}$), we interpret the gases to be of predominantly biogenic origin which were generated by the methanogenic bacterial processes under the low temperature and anoxic conditions.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.71-85
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• 2014

To study biogeochemical characteristics and origin organic matter, sediment samples were taken from Site of 1249C and Stie 1251B of ODP Leg 204. Data of Rock-Eval, isotope, and element analysis generally indicate dominance of marine organic matter in sediments deposited under marine sedimentary environment. Only Rock-Eval data are somewhat different from those of others owing to under-maturation of organic matter. Samples of Site 1249C show high content of gas hydrate, whereas Site 1251B low content of gas hydrate in some intervals of the core. This result may be accounted to different location of two cores and presence of transportation passage (Horizon A, BSR 2) of thermogenic gas in the core, 1249 C. However, Site 1251B Located in the basin of low accumulation of gas hydrate is presumed to be limited in the gas hydrate production. Because not only transportation passage is limited to move thermogenic gas from the core, but also gas supply was not enough. Therefore, the biogenic gas that resulted from diagenesis of there sediment is superior.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.531-538
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• 2017

Agricultural products produced in the agricultural area around the nuclear power plant are radioactive contamination, which can cause radioactive contamination to the human body. The purpose of this study was to investigate the limit of the radioactivity concentration $^{90}Sr$ for the internal exposure dose evaluation by ingesting the agricultural products collected around the nuclear power plant. The results of the gamma-isotope element analysis were freshly <0.0166-0.0336 Bq / kg for all samples and for artificial radionuclides not detected, and fresh <0.00586-0.0421 Bq / kg for Chinese cabbage, The freshness was 0.106 Bq / kg, and the freshness was 0.0114-0.0901 Bq / kg. 0.0177%, 0.0222%, 0.0376% and 0.00243%, respectively, for Chinese cabbages and large roots, which is lower than the legal standard value of $1mSv/yr{\cdot}man%$. It is considered that the formulas need to be broadly evaluated for the foods consumed by children and adults, taking into consideration the age of the food and the diet

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.123-134
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• 2012

Hydrochemical analyses, carbon isotopic (${\delta}^{13}C_{DIC}$) analyses, and noble gas isotopic ($^3He/^4He$ and $^4He/^{20}Ne$) analyses of the Dalki carbonate waters in the Chungsong area were carried out to elucidate their hydrochemical composition and to determine the source of $CO_2$ gas and noble gases. The carbonate waters have a pH of between 5.93 and 6.33, and an electrical conductivity 1950 to $3030{\mu}S/cm$. The chemical composition of all carbonate waters was Ca(Mg)-$HCO_3$, with a high Na content. The contents of Fe, Mn, and As in some carbonate waters exceed the limit stipulated for drinking water. The concentrations of major ions are slightly higher than those reported previously. The ${\delta}^{13}C_{DIC}$ values range from -6.70‰ to -4.47‰, indicating that the carbon originated from a deep-seated source. The $^3He/^4He$ and $^4He/^{20}Ne$ ratios vary from $7.67{\times}10^{-6}$ to $8.38{\times}10^{-6}$ and from 21.32 to 725.7, respectively. On the $^3He/^4He$ versus $^4He/^{20}Ne$ diagram, the noble gas isotope ratios plot in the field of a deep-seated source, such as mantle or magma. We therefore conclude that $CO_2$ gas and noble gas in the Dalki carbonate waters originated from a deep-seated source, rather than an inorganic $CO_2$ origin as suggested in a previous study.

• The Korean Journal of Quaternary Research
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• v.16 no.1
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• pp.1-16
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• 2002

A total of 4 muddy sediment samples collected from the Central Yellow Sea were analyzed for chemical composition. The results are compared with the previously published Huanghe, Changjiang and Keum River geochemical data in order to understand provenance and sedimentation of fine-grained mud, and the sediment accumulation rates estimated. The sandy sediment facies is distributed in the eastern area, a patch of fine-grained mud exists in the western central prat, and the sandy mud and clay sedimentary facies shot. north to south zonal distribution in the central region. The content of calcium carbonate ranges from 2.8 to 10.5%, and its distributional trends to be more concentrated on the western muddy sediments near toward the China side rather than on the eastern sandy sediments. The accumulation rates obtained using Pb-210 geochronologies for the muddy sediments in the Central Yellow Sea showed ranges from 0.21 to 0.68 cm/yr or 0.176 to 0.714 g/$\textrm{cm}^2$. yr. The sedimentation rate from core CY96010 located in the eastern near side of Shandong Peninsula which is affected by the Huanghe River shows 0.68 cm/yr or 0.714 g/$\textrm{cm}^2$ . yr. The sediment cores CY96008 and CY96002 in the Central Yellow Sea, the estimated of sediment accumulation rates shows 0.21~0.23cm1yr or 0.176~0.220 9/$\textrm{cm}^2$.Vr respectively, which are much lower than above samples. These indicate that the muddy sediments in central area of the Yellow Sea may have received influence of the sediment discharge from the Huanghe River. The concentrations of Ca, Na, Sr, Ho, La, Tb, Ta and Ca/Ti ratio of the muddy sediments in the Central Yellow Sea are higher than those of the Changjiang sediments and lower than those of the Huanghe sediments. However, these element values showed similar concentration patterns than those of the Huanghe sediment. The element contents such as Fe, Ti, Nl, Co, Cr, Cu, Pb, Sc, Ce, Nd, Sm, Eu, Cd and Dy in the study area are higher than those of the Huanghe sediments and lower than the Changjiang River sediments, but these values showed close to resemblance content trends those of the Changjiang sediment. The concentration of Mn, K and Sr in sediments of the study area are similar to those of the Keum River and eastern Yellow Sea sediment. They are rich in Zn, Rb, Cd, U, Cs and Li than those of the other comparison legions. Therefore, the terrigenous materials sources of the muddy sediment in the Central Yellow Sea comes mainly from Huanghe River in the past and present, and also have party derived from the Changjiang and Keum River, while the biological deposit in this area are carried by the Yellow Sea Warm Current.

• Economic and Environmental Geology
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• v.23 no.4
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• pp.369-381
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• 1990

Most of significant ore deposits in South Korea such as the Sangdong W - Mo, the Yeonhwa Pb-Zn and the Geodo Cu-Fe skarn ore deposits occur at the southern limb of the Hambaeg syncline in the Taebaeg Basin. The mineralization took place in the interbedded limestone of the Myobong Formation and the Pungchon limestone of the Great Limestone Group of the Cambrian age, generally striking E-W and dipping 25-30 degrees north. There are no outcrops of the skarn-type orebody at the northern limb of the syncline. In order to find a clue of a possible hidden orebody localized at the limestones in the northern limb, a lithogeochemical exploration by using carbon isotope and some elements such as Si, Ca, Fe and Al at the Sangdong Mine area has been attempted as for a modelling study. For this study, 45 samples from the Pungchon limestone which do not show any megascopic indication of mineralization have been taken in both the mineralized zone and the unminerallized zone at the Sangdong Mine area. Analytical data show that there are big differences in the contents of CaO and $Al_2O_3$ between the Pungchon limestone of the mineralized zone and that of the unmineralized zone. Carbon isotope data exhibit that ${\delta}^{13}C$ values of the Pungchon limestone in the mineralized zone are highter than those in the unmineralized zone. The difference in the analytical values of CaO, $Al_2O_3$ and the carbon isotope between the mineralized and the unmineralized zones is as follows ; Unminerallized zone Mineralized zone CaO 51.3% 43.5% $Al_2O_3$ 0.6% 2.4% ${\delta}^{13}C$ -0.39 permil -0.56 permil $Fe_2O_3$ 0.9% 1.4% $SiO_2$ 3.0% 2.4% The decrease in the Si content of the Pungchon limestone in the mineralized zone is contrary to the result of the previous study (Moon, 1987). On the basis of identification of the increase in the Al content of the limestone in the mineralized zone, it could be deduced that the decrease in the Si content of the Pungchon limestone might be due to the result of increase in the alteration products mainly occurred along fracture-system such as joint cracks or minor faults and that the phenomena shown by the Si and Al content in the mineralized zone might be derived from the thermal effect of granite extended mineralizing activity to the overlied limestone on the surface. Higher mean values of Fe and Al as well as lower mean values of carbon content and the ${\delta}^{13}C$ than mean values of those in the Pungchon limestone at the northern limb of the Hambaeg Syncline may be applicable in exploration for blind orebodies.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.457-474
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• 2019

Since 1966 when the Journal of the Korean Society of Oceanography was founded, more than 1,200 scientific papers have been published. Among them, papers for the biological oceanography constitute the largest portion of 37%, followed by the physical oceanography with 25%, and then the geological oceanography with about 17%. Papers on the chemical oceanography (CO) accounts for about 20% with around 250 papers. The field of the chemical oceanography generally occupied more than 20% since the first issue, but it declined down to 10% from the 1980s to the 1990s, and has regained to more than 20% since the late 1990s. Most of the CO research sites were at Korean coastal area, and 1/3 of the papers were on the South Sea, 1/4 on the Yellow Sea and another 1/4 on the East Sea. Nearly 60% of the CO papers were on seawater studies and about 30% on sediment studies. The main topic of the CO research was nutrients, followed by metals, isotopes, environmental pollution, organic pollution, organic matter, and gases. Most of the first authors belonged to the university, but the Korea Institute of Ocean Science and Technology (including the whole body) was the affiliation with the single largest group of the first authors.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.99-108
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• 2008

The paleogenetic analysis has become an increasingly important subject of archaeological, anthropological, biological as well as public interest. Recently, scientific research for human skeletal remains was more activated because of increasing awareness of the valuable archaeological information by the ancient DNA analysis. State of preservation of organic remains vary in different soil and burying environmental condition. Almost all available tissue disappear to analysis ancient DNA of bone in acidic soil caused by climate and geological features in Korea. Many preserved human remains excavated in the 'Heogwakmyo'(limelayered tomb of Chosun Dynasty Period) is able to explain through the relationship between burial conditions and bone survival form the burial method and ceremony. Ancient DNA analysis of excavated human bone form ancient tomb requires to remove contaminants such as microorganism's DNA and soil components that affect authentic results. Particularly, contamination control of contemporary human DNA is major serious problem and should verified by criteria of authenticity. In order to understand migration and culture of ancient population, when possible, ancient DNA studies needs to go abreast both radiocarbon and stable isotope studies because the dietary inferences will suggest ancient subsistence and settlement patterns. Also when the paleogenetic research supported with the arts and humanities research such as physical anthropology and archaeology, more valuable ancient genetic information is providing a unique results about evolutionary and population genetics studies to reconstruct the past.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.30-30
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• 2020

본 연구에서는 여름철에 농업용수(벼농사용)로서 집중적으로 지하수를 사용하는 지역에서 시기별 지하수 사용에 따른 지하수 수질변화를 평가하기 위해 수행되었다. 연구지역은 충남 홍성군 양곡리와 신곡리 일부를 포함하는 면적 2.83 ㎢(283.3 ha)에 해당하는 지역이다. 연구지역 지하수 수질의 공간적 분포 및 시간적 변화 특성 평가를 위하여 2019년 2회(7월, 10월)에 걸쳐 지하수 관정(21개소)에 대하여 조사 및 분석을 수행하였다. 지하수 샘플은 현장에서 온도(T), pH, 용존산소(DO) 및 전기전도도(EC), 산화환원전위(Eh) 등을 측정하였고, 실험실에서 주요 양이온 및 미량원소(Ca, Mg, Na, K, Si, Sr), 음이온(F, Cl, Br, NO₂, NO₃, PO₄, SO₄), 알칼리도, 용존 유기탄소(DOC)와 용존 유기물(DOM) 등을 분석하였다. 지하수 수질조사 결과, 전체의 14~15개소(67~71%)가 Ca-HCO₃ 유형으로 분류되었으며, 다음으로는 Ca-Cl 유형이 4~5개소(19~24%)가 관찰되었다. 얕은 심도의 관정에서 상대적으로 심도가 깊은 관정보다 대부분 성분(TDS, Ca, Mg, Na, K, Cl, SO₄, HCO₃, DOC)에서 높은 농도를 나타내었다. 지하수의 수질자료를 이용하여 다변량통계분석법인 주성분분석(PCA: Principal Components Analysis)과 계층적 군집분석(HCA: Hierachical Cluster Anlaysis)를 수행한 결과, 초기 3개 주요 고유성분(eigenvalue)는 PC1 54.0%, PC2 14.2%, PC3 12.3%로 전체 분산의 88.3%를 설명할 수 있었다. PC1은 Ca, Mg, Na, K, Cl, SO₄, DOC가 주요한 영향 인자였으며 PC2는 HCO₃, NO₃, DO에 영향 받음을 확인하였다. 계층적 군집분석 결과, 연구지역 지하수는 Na-Cl 유형의 C-3 관정을 제외하고는 크게 두 그룹으로 구분되어 졌다. 다변량통계분석의 결과에서도 수리지화학, 동위원소, 용존유기물 등의 특성에서 나타나는 것과 유사한 연구지역의 수질특성을 확인할 수 있었다. 연구지역은 차시기 동안 수질변화는 일부 관정을 제외하고는 유의할 만한 수준으로 관찰되지는 않았고, 지하수 사용에 따른 지하수위 회복도 빠르게 진행되고 있는 것으로 나타났다.