• Title/Summary/Keyword: $^3He/^4He$ 동위원소비

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Origin and Hydrochemical Characteristics of Natural Carbonated Water at Seoqwipo, Jeju Island (제주도 서귀포지역 천연탄산수의 기원과 수리화학특성)

  • Jeong, Chan Ho;Lee, Yong Cheon;Lee, Yu Jin;Choi, Hyeon Young;Koh, Gi Won;Moon, Duk Chul;Jung, Cha Youn;Jo, Si Beom
    • The Journal of Engineering Geology
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    • v.26 no.4
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    • pp.515-529
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    • 2016
  • In this study, geochemical composition, CFCs (Chlorofluorocarbons), ${\delta}^{18}O$, ${\delta}D$, ${\delta}^{13}C$ isotopes and noble gases isotopes (He, Ne) were analyzed to determine their recharge age, source of $CO_2$ gas and noble gases of carbonated hot spring water and carbonated-water samples collected in the Seoqwipo of the Jeju. The pH of the carbonated waters ranges from 6.21 to 6.84, and the high electrical conductivity range ($1,928{\sim}4,720{\mu}S/cm$). Their chemical composition is classified as $Mg(Ca,\;Na)-HCO_3$ and $Na(Ca,\;Mg)-HCO_3$ types. As a result of the calculation of groundwater age using CFCs concentrations as an environmental tracer, the carbonated water and groundwater were estimated to be about 47.5~57.2 years and about 30.3~49.5 years, respectively. The ${\delta}^{13}C$ values of carbonated water range from -1.77 to -7.27‰, and are plotted on thr deep-seated field or the mixing field of the deep-seated and inorganic origin. Noble gases isotopic ($^3He/^4He$, $^4He/^{20}Ne$) ratio shows that helium gas of carbonated hot waters comes from deep-seated magma origin.

(U-Th)/He Dating: Principles and Applications ((U-Th)/He 연령측정법의 원리와 응용)

  • Min, Kyoung-Won
    • The Journal of the Petrological Society of Korea
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    • v.23 no.3
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    • pp.239-247
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    • 2014
  • The (U-Th)/He dating utilizes the production of alpha particles ($^4He$ atoms) during natural radioactive decays of $^{238}U$, $^{235}U$ and $^{232}Th$. (U-Th)/He age can be determined from the abundances of the parent nuclides $^{238}U$, $^{235}U$ and $^{232}Th$ and the radiogenic $^4He$. Because helium is one of the noble gases (non-reactive) with a relatively small radius, it diffuses rapidly in many geological materials, even at low temperatures. Therefore, ingrowth of $^4He$ during radioactive decay competes with diffusive loss at elevated temperatures during the geologic time scale, determining the amount of $^4He$ existing today in natural samples. For example, He diffusion in apatite is known to be very rapid compared to that in most other minerals, causing a significant diffusive loss at ${\sim}80^{\circ}C$ or higher. At ${\sim}40^{\circ}C$, He diffusion in apatite becomes slow enough to preserve most $^4He$ in the sample. Thus, an apatite's (U-Th)/He age represents the timing when the sample passed through the temperature range of $80-40^{\circ}C$. The crustal depth corresponding to this temperature range is called a "partial retention zone." Normal closure temperatures for a typical grain size and cooling rate are ${\sim}60-70^{\circ}C$ for apatite and ${\sim}200^{\circ}C$ for zircon and titanite. Because the apatite He closure temperature is lower than that of most other thermochronometers, it can provide critical constraints on relatively recent or shallow-crustal exhumation histories.

Pharmacological Effect of Hawangyeonhaedoktang on Experimental Triglyceride Accumulated HepG2 Cells (실험적 중성지질 축적 HepG2세포에 미치는 황련해독탕의 약리적 효과)

  • 차재영;김대진;김석환;김영길;조영수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.4
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    • pp.586-590
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    • 2003
  • The pharmacological effect of Korean-Chinese traditional herbal medicine, Hawangyeonhaedoktang (HT) on experimentally induced-triglyceride accumulation in cultured human hepatocyte HepG2 cells was studied. HePG2 cells were cultured in the Dulbecco's modified Eagle's (DME) medium without (Control medium) or with HT (0.5 mg/mL and 5.0 mg/mL) containing 1 mM oleate, 0.2% bovine serum albumin (BSA), and glucose 4.5 mg/mL for 6 and 24 hours in experiment I and 2 mM oleate, 0.5% BSA, and glucose 4.5 mg/mL for 6, 24 and in hours in Experiment II or 1 and 3 hours in Experiment III. Oleate [$^{14}$ C](0.5 $\mu$Ci/mL medium) added as a radioactive lipid precursor in the experiment I. In the experiment I, the intracellular triglyceride concentration was decreased remarkably during incubation for 6 and 24 hours, in a dose-dependent manner. At the same time, HT caused a decrease in the incorporation of [$^{14}$ C] oleate into intracellular triglyceride fraction and the secretion of triglyceride labeled with [$^{14}$ C] oleate into medium. In the experiment II and III compared to experiment I, the triglyceride accumulation in HepG2 cells was occurred, and HT prevented the accumulation of triglyceride during incubation for 24 and 48 hours. This result suggest that HT prevent the triglyceride accumulation in human hepatocytes by its inhibiting action on the intercellular triglyceride biosynthesis.

Occurrence of Natural Radioactive Materials in Borehole Groundwater and Rock Core in the Icheon Area (이천지역 시추공 지하수와 시추코어내 자연방사성물질 산출 특성)

  • Jeong, Chan-Ho;Kim, Dong-Wook;Kim, Moon-Su;Lee, Young-Joon;Kim, Tae-Seung;Han, Jin-Seok;Jo, Byung-Uk
    • The Journal of Engineering Geology
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    • v.22 no.1
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    • pp.95-111
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    • 2012
  • This study investigated the relationship between the geochemical environment and the occurrence of natural radioactive materials (uranium and Rn-222) in borehole groundwater at an Icheon site. The drill core recovered from the study site consists mainly of biotite granite with basic dykes. The groundwater samples were collected at four different depths in the borehole using the double-packed system. The pH range of the groundwater was 6.5~8.6, and the chemical type was Ca-$HCO_3$. The ranges of uranium and Rn-222 concentrations in the groundwater were 8.81~1,101 ppb and 5,990~11,970 pCi/L, respectively, and concentrations varied greatly with depth and collection time. The ranges of uranium and thorium contents in drill core were 0.53~18.3 ppm and 6.66~17.5 ppm, respectively. Microscope observations and electron microprobe analyses revealed the presence of U and Th as substituted elements for major composition of monazite, ilmenite, and apatite within K-feldspar and biotite. Although the concentration of uranium and thorium in the drill core was not high, the groundwater contained a high level of natural radioactive materials. This finding indicates that physical factors, such as the degree of fracturing of an aquifer and the groundwater flow rate, have a greater influence on the dissolution of radioactive materials than does the geochemical condition of the groundwater and rock. The origin of Rn-222 can be determined indirectly, using an interrelationship diagram of noble gas isotopes ($^3He/^4He$ and $^4He/^{20}Ne$).

Analysis of Unrest Signs of Activity at the Baegdusan Volcano (백두산 화산의 전조활동 분석 연구)

  • Yun, Sung-Hyo;Lee, Jeong-Hyun
    • The Journal of the Petrological Society of Korea
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    • v.21 no.1
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    • pp.1-12
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    • 2012
  • The Baegdusan volcano is one of the most active volcanoes in northeastern Asia, and the 10th century eruption was the most voluminous eruption in the world in recent 2,000 years. During the period from 2002 to 2005, volcanic earthquakes and abnormal surface distortions by suspected subsurface magma intrusion beneath the volcano were observed in the Baegdusan area. Seismic activity has gradually increased with earthquake swarms during 2002-2003 and hundreds of seismic event in a day, especially annual peak of 2,100 in 2003. Then the number of seismic activity has declined since 2006 to the background level in 1999-2001. According to the typical frequency of volcanic earthquakes in the Baegdusan volcano, the frequency distribution of typical volcanic earthquakes between 2002 and 2005 indicates that all the main frequency of the earthquakes basically falls down less than 5 Hz and 5-10 Hz. These events are all the VT-B and LP events caused by the shallow localized fracture and intrusion of magma. The horizontal displacement measurement by GPS during the period from 2000 to 2007 of the Baegdusan stratovolcano area indicates that an inflated process has been centered at the summit caldera since 2002. The displacement between 2002 and 2003 reached at a maximum value of 4 cm. After 2003, the deformation rate of the volcano continued to decrease with unusual variation during the period from 2006 to 2007. After 2003 the vertical displacement uplift rate falls down gradually but still keeps in an uplift trend in northern slope. It is generally believed that when $^3He/^4He(R)$ in a gas sample from a hot spring exceeds $^3He/^4He(R)$ in the atmosphere, it can be concluded that mantle-source. And temperatures of hot springs are rising steadily to $83^{\circ}C$. It is unrest signals at the Baegdusan, which is potentially active. The Baegdusan volcano is now in unrest status, there is eruption threat in the near future. Intensified monitoring and emergency response plan for volcanic risk mitigation are urgent for the volcano.

Acid Drainage and Damage Reduction Strategy in Construction Site: An Introduction (건설현장 산성배수의 발생현황 및 피해저감대책)

  • Kim, Jae-Gon
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.651-660
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    • 2007
  • Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

Hydrochemistry and Occurrence of Natural Radioactive Materials within Borehole Groundwater in the Cheongwon Area (청원지역 시추공 지하수의 수리화학 및 자연방사성물질 산출 특성)

  • Jeong, Chan-Ho;Kim, Moon-Su;Lee, Young-Joon;Han, Jin-Seok;Jang, Hyo-Geun;Jo, Byung-Uk
    • The Journal of Engineering Geology
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    • v.21 no.2
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    • pp.163-178
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    • 2011
  • A test borehole was drilled in the Cheongwon area to investigate the relationship between geochemical environment and the natural occurrence of radioactive materials (uranium and Rn-222) in borehole groundwater. The borehole encountered mainly biotite schist and biotite granite, with minor porphyritic granite and basic dykes. Six groundwater samples were collected at different depths in the borehole using the double-packed system. The groundwater pH ranges from 5.66 to 8.34, and the chemical type of the groundwater is Ca-$HCO_3$. The contents of uranium and Rn-222 in the groundwater are 0.03-683 ppb and 1,290-7,600 pCi/L, respectively. The contents of uranium and thorium in the rocks within the borehole are 0.51-23.4 ppm and 0.89-62.6 ppm, respectively. Microscope observations of the rock core and analyses by electron probe microanalyzer (EPMA) show that most of the radioactive elements occur in the biotite schist, within accessory minerals such as monazite and limenite in biotite, and in feldspar and quartz. The high uranium content of groundwater at depths of -50 to -70 m is due to groundwater chemistry (weakly alkaline pH, an oxidizing environment, and high concentrations of bicarbonate). The origin of Rn-222 could be determined by analyzing noble gas isotopes (e.g., $^3He/^4He$ and $^4He/^{20}Ne$).

Development of Multimedia Annotation and Retrieval System using MPEG-7 based Semantic Metadata Model (MPEG-7 기반 의미적 메타데이터 모델을 이용한 멀티미디어 주석 및 검색 시스템의 개발)

  • An, Hyoung-Geun;Koh, Jae-Jin
    • The KIPS Transactions:PartD
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    • v.14D no.6
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    • pp.573-584
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    • 2007
  • As multimedia information recently increases fast, various types of retrieval of multimedia data are becoming issues of great importance. For the efficient multimedia data processing, semantics based retrieval techniques are required that can extract the meaning contents of multimedia data. Existing retrieval methods of multimedia data are annotation-based retrieval, feature-based retrieval and annotation and feature integration based retrieval. These systems take annotator a lot of efforts and time and we should perform complicated calculation for feature extraction. In addition. created data have shortcomings that we should go through static search that do not change. Also, user-friendly and semantic searching techniques are not supported. This paper proposes to develop S-MARS(Semantic Metadata-based Multimedia Annotation and Retrieval System) which can represent and extract multimedia data efficiently using MPEG-7. The system provides a graphical user interface for annotating, searching, and browsing multimedia data. It is implemented on the basis of the semantic metadata model to represent multimedia information. The semantic metadata about multimedia data is organized on the basis of multimedia description schema using XML schema that basically comply with the MPEG-7 standard. In conclusion. the proposed scheme can be easily implemented on any multimedia platforms supporting XML technology. It can be utilized to enable efficient semantic metadata sharing between systems, and it will contribute to improving the retrieval correctness and the user's satisfaction on embedding based multimedia retrieval algorithm method.