• Journal of Chest Surgery
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• v.35 no.3
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• pp.171-176
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• 2002

Background: Blood-foreign interaction cause activation of coagulation and inflammatory process that may lead to multiorgan dysfunction and determine the surgical outcomes. Of the methods for assessing the biocompatibility, the platelet adhesion study is considered as the most valuable evaluation step in blood-foreign interaction. As the most studies have used in-vitro or ex-vivo conditions, we have developed a technique of quantification for platelet adhesion on the blood contact surface by using in-vivo injection of radioactive platelets. Material and Method: A coupled bypass circuit was designed to connect the proximal and descending thoracic aorta in 6 piglets(20∼25 Kg). One side of the circuit tube was consisted of a heparin coated PVC tube(10mm in ID, n=6, Experimental group), and the other, a non-heparin coated PVC tube(10mm in ID, n=6, Control group). After cannulation, the blood was circulated through the circuit for 2 hours. Platelet concentrate was prepared from homologous pig blood 24 hours before the experiment. The platelet concentrate was incubated with Tc-99m-HMPAO for 30 min and then centrifuged for 10 min. The supernatant was discarded and the radio-labeling efficacy was measured. The radio-labeled platelet concentrate was mixed with the autologous plasma to make the volume 5 ml, and the mixture was injected intravenously into the experimental animal. After 2 hour circulation, 5 pieces of the specimen(10mm in length each) were obtained from each PVC tube. The radioisotopes were counted with a gamma counter(Cobra ll, Packard, USA), and the ratio of radioisotope count was compared between the control and experimental group. Result: The radioisotope count number was 537.3221.1 Ci/min in the control group and 311.1 184.5 Ci/min in the experimental group(p=0.0104). The ratio between the groups was 1 to 0.58 (p=0.004). Conclusion: In vivo quantification using technetium-99m-HMPAO labeled platelets is simple and reproducible in evaluating platelet adhesion on a foreign surface. We suggest this technique to be a useful tool for blood compatibility test.

• Journal of Powder Materials
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• v.26 no.5
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• pp.432-436
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• 2019

This study demonstrates the effect of addition of Fe particles of different sizes on the critical properties of the superconductor $MgB_2$. Bulk $MgB_2$ is synthesized by ball milling Mg and B powders with Fe particles at $900^{\circ}C$. When Fe particles with size less than $10{\mu}m$ are added in $MgB_2$, they easily react with B and form the FeB phase, resulting in a reduction in the amount of the $MgB_2$ phase and deterioration of the crystallinity. Accordingly, both the critical temperature and the critical current density are significantly reduced. On the other hand, when larger Fe particles are added, the $Fe_2B$ phase forms instead of FeB due to the lower reactivity of Fe toward B. Accordingly, negligible loss of B occurs, and the critical properties are found to be similar to those of the intact $MgB_2$.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.171-179
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• 1999

The $CO_2$-rich waters in the Chojeong area are characterized by low pH (5.0~5.8), high $CO_2$pressure (about 1 atm) and high amounts of total dissolved iou (up to 989 mg/L) and chemically belong to Ca-HC $O_3$type. The oxygen. deuterium and tritium isotope data indicate that the mixing process occurred between $CO_2$-rich water and surface water and/or shallow groundwaters and also suggest that the $CO_2$-rich water has been derived from meteoric waters. According to $\delta$$^{13}$ C values (-8.6~-5.3$\textperthousand$). the $CO_2$ in the water is attributed from deep seated $CO_2$gas. The high dissolved carbon (-14.4~-6.8$\textperthousand$. $\delta$$^{13}$ C) in groundwater of the granitic terrain might be affected by $CO_2$-rich water, whereas the dissolved carbon (-17.9~-15.2$\textperthousand$. $\delta$$^{13}$ C) in groundwater of the metamorphic terrain is likely controlled by soil $CO_2$ and from the reaction with calcite in phyllite. Sulfur isotope data (＋3.5~＋11.3$\textperthousand$,$\delta$$^{34}$ $S_{SO4}$) also support the mixing process between $CO_2$-rich water and shallow groundwater. Strontium isotopic ratio ($^{87}$ Sr/$^{86}$ Sr) indicates that the $CO_2$-rich water (0.7138~0.7156) is not related to vein calcite (0.7184) of Buak mine or calcite (0.7281~0.7346) in phyllite. By nitrogen isotope ($\delta$$^{15}$ $N_{NO3}$) the sources of nitrogen (up to 55.0 mg/L, N $O_3$) in the $CO_2$-rich water are identified as fertilizer and animal manure. It also indicates the possibility of denitrification during the circulation of nitrogen in the Chojeong area. The possible evolution model of the $CO_2$-rich water based on the hydrochemical and environmental isotopic data was proposed in this study. The $CO_2$-rich waters from the Chojeong area were primarily derived from the reaction with granite by supply of deep seated $CO_2$. and then the $CO_2$-rich water was mixed and diluted with the local groundwater.ter.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.

• Proceedings of the KSEG Conference
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• 2002.04a
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• pp.129-136
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• 2002

대전광역시의 도심하천인 갑천, 유등천, 대전천을 대상으로 하천수의 수리화학적 특성과 동위원소 특성을 분석하였다. 하천의 수리화학적 특성은 상류에서는 $Ca(Mg)-HCO_3$ 유형을 보이다가 도심권을 통과하면서 $Ca(Mg)-SO_4(Cl)$유형으로 전환되고 하류에서는 $Na(Ca)-HCO_3(Cl,{\;}SO_4)$ 유형으로 변화를 보였다. 이와 같은 화학적 유형의 변화는 자연적 영향보다는 인위적 오염물질의 유입에 의한 것으로 해석된다. 하천수의 전기전도도와 수리화학적 유형으로 보면 대전천보다는 유등천과 갑천이 비교적 좋은 수질특성을 보인다. 그러나 하수종말처리장에서 방류되는 방류가 합류되는 갑천하류부터는 수질이 급격하게 나빠진다. 하천수의 pH는 상류에서 중성을 보이다가 도심권을 지나면서 최고 pH 9.8정도의 알카리성을 보인다. 이는 아파트의 우수관을 통한세제 유입에 기인하는 것으로 보인다. 하천수의 ${\delta}^{13}l3C-HCO_3$ 관계에서 중탄산 함량의 증가에 따른 ${\delta}^{13}C$ 값의 증가는 하천수내 $CO_2$의 기원이 유기물에서 무기물의 영향이 커짐을 의미한다. ${\delta}^{34}S-SO_4$의 함량관계는 황산염의 농도가 증가함에 따라서 ${\delta}^{34}S$ 값은 낮아진다. 갑천, 유등천, 대전천의 순으로 황산염의 농도가 증가하고 ${\delta}^{34}S$ 값은 낮아지는 경향을 보인다. 이를 바탕으로 볼 때 갑천 중상류의 경우에는 황산염의 기원이 자연적 반응외 비료 등으로부터 유입된 것으로 보이며, 대전천의 경우에는 유기오염에 의한 황산염의 유입이 상당한 것으로 판단된다. 갑천하류는 하수종말처리장의 방류수의 영향이 큰 것으로 해석된다. 대전시 도심하천수의 수리화학적수질 개선을 위해서는 하수종말처리장의 방류수 기준의 강화, 아파트단지에서의 세제의 유입의 차단, 그리고 부분적인 오염물질의 유입을 차단하여야 할 것이다.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.391-405
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• 2005

Chemical and isotopic analysis for stream water, shallow groundwater, intermediate groundwater and deep groundwater was carried out to grasp hydrogeochemical characteristics of groundwater in the Heunghae area, Pohang city. Water type of stream water and shallow groundwaters is typified as Ca-Cl type, intermediate groundwater is $Na-HCO_3$, and deep groundwater is prominent in Wa-Cl type. $HCO_3^-\;and\;SiO_2$ in shallow groundwater are originated from weathering of silicate minerals, whereas those of deep groundwaters are resulted from weathering of carbonate minerals. Ca and Mg ions in both shallow and deep groundwaters are resulted from weathering of calcite and dolomite. $SO_4^{2-}$ in shallow groundwater is originated mainly from pyrite oxidation. As well depth increases, pH and TDS increase, but Eh and DO decrease. Alkali metal contents(K, Na, Li) increases as well depth increases, but alkali earth metal(Mg, Ca) and hi concentrations increase as well depth decreases. Anions, halogen elements(F, Cl, Br), and $HCO_3$ contents increase as well depth increases. The average stable isotope value of the groundwater of each depth is as follows; deep groundwater: ${\delta}^{18}O=-10.1\%o,\;{\delta}D=-65.8\%_{\circ}$, intermediate groundwater: ${\delta}^{18}O=-8.9\%_{\circ},\;{\delta}D=-59.6\%_{\circ}$, shallow groungwater : ${\delta}^{18}O=-8.0\%_{\circ},\;{\delta}D=-53.6\%_{\circ}$, surface water : ${\delta}^{18}O=-7.9\%_{\circ},\;{\delta}D=-53.3\%_{\circ}$ respectively.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.183-197
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• 2022

Geochemical data, including Sr-Nd-Pb-Mg-Zn isotopes, reported on the late Cenozoic intraplate basaltic rocks in the Korean Peninsula (Mt. Baekdu, Jeongok, Baengnyeong Island, Pyeongtaek, Asan, Ganseong, Ulleung Island, Dok Island, and Jeju Island) are summarized to constrain their mantle source lithologies, and the nature of mantle end-members required. In the Sr-Nd isotope correlation diagram, Jeju basalts plot in the field of EM2-type oceanic island basalts (OIB), while the other basalts fall in the EM1-type OIB field. In Pb-Pb isotope space, Jeju basalts show a mixing array between Indian MORB and EM2 component, whereas the other basalts display an array with EM1 component. The Korean basalts were derived from a hybrid source of garnet lherzolite and recycled stagnant slab materials (eclogite/pyroxenite, pelagic sediments, carbonates) in the mantle transition zone. The EM1 component could be ancient (~2.0 Ga) K-hollandite-bearing pelagic sediments that were isolated for a long period in the mantle transition zone due to their neutral buoyancy. The EM2 component might have been relatively young (probably Pacific slab) and recently recycled clay-rich pelagic sediments. Eclogite and carbonates are unlikely to account for the EM components, but they are common in the mantle source of the Korean basalts.

• Economic and Environmental Geology
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• v.33 no.6
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• pp.469-489
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• 2000

The hydrogeochemical and isotopic studies on deep groundwater (below a 550 m depth from the ground surface) in the Munkyeong area, Kyeongbuk province were carried out. Two types of deep groundwater (${CO_2}$-rich groundwater and alkali groundwater) occur together in the Munkywong area. ${CO_2}$-rich groundwater (Ca-${HCO_3}$ type) is characterized by low pH (5.8~6.5) and high TDS (up to 2,682 mg/L.), while alkali groundwater (Na-${HCO_3}$ type) shows a high pH (9.1~10.4) and relatively low TDS (72~116 mg/L). ${CO_2}$-rich water may have evolved by ${CO_2}$ added at depth during groundwater circulation. This process leads to the dissolution of surrounding rocks and Ca, Na, Mg, K and ${HCO_3}$ concentrations are eniched. The low $Pco_2$ ($10^{-6.4}$atm) of alkali groundwaters seems to result from the dissolution of silicate minerals without a supply of ${CO_2}$. The ${\delta}^{18}O$ and ${\delta}^D$values and tritium data indicate that two types of deep groundwater were both derived from pre-thermonuclear meteoric water and have evolved through prolonged water-rock interaction. The carbon isotope data show that dissolved carbon in the ${CO_2}$-rich water was possibly derived from deep-seated ${CO_2}$ gas, although further studies are needed. The ${\delta}^{34}S$ values of dissolved sulfate show that sulfate reduction occurred at great depths. The application of various chemical geothermometers on ${CO_2}$-rich groundwater shows that the calculated deep reservoir temperature is about 130~$l75^{\circ}C$. Based on the geological setting, water chemistry and environmental isotope data, each of the two types of deep groundwater represent distinct hydrologic and hydrogeochemical evolution at depth and their movement is controlled by the local fracture system.

• 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.

• The Journal of the Petrological Society of Korea
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• v.12 no.3
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• pp.135-153
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• 2003

In order to understand its origin and petrogenesis, petrochemical studies of major, trace elements, REE, and stable isotopes of oxygen and carbon from the Hongcheon Fe-REE deposits have been investigated. The Hongcheon Fe-REE deposit intruding into Precambrian metasedimentary rocks consists of magnetite, various carbonates such as ankerite, siderite, magnesite and strontianite, monazite, aegirine-augite, Na-amphibole, and sulfides. Compared with major elements abundances of typical ferro-carbonatites, the Hongcheon Fe-REE deposit is enriched in FeO and depleted in CaO with increasing of $SiO_2$, where $TiO_2$and $A1_2O_3$increased and CaO, FeO, MgO and $P_2O_5$ are slightly decreased, but those are rather scattered and their trends are somewhat ambiguous. V Ni, U and Rb slightly increasing with of $SiO_2$increase and scattering or no trends of other detected elements. Nb, Zr and Zn are depleted then the abundances of typical ferro-carbonatites (Woolley and Kempe, 1989). In rare earth elements a large enrichment of total REE (maximum 14.8 wt%) and LREE relative to chondrites and HREE depleted more then the values of ferro-carbontites therefore La/Lu ratios shows large abundances (max. 16,197). The results of stable isotopes of O and C from minerals of ankerite and strontianite and whole rocks represent studied rocks are from igneous carbonatitic melts. Although petrochemical characteristics of the Hongcheon Fe-REE deposits are somewhat different from normal ferro-carbonatites from the world, this discrepancy suggests another conclusion that petrochemical characteristic of the studied Fe-REE mineralized rocks are similar to those of phoscorites from Kovdor, Russia and Sokli, Finland showing the same petrochemical compositions described above.