• Economic and Environmental Geology
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• v.41 no.1
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• pp.63-79
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• 2008

Physicochemical characteristics of stream water, leachate, mine water and groundwater were investigated to estimate the influences of the tailing and waste rock from the abandoned Uljin mine area. Total extraction analysis and mineralogical studies were carried out to understand sulfide weathering and to determine the distributions of trace elements in the soil affected by mine waste (tailing, waste rock and leachate). The pH and EC value of the leachate from the tailing disposal ranged 2.9-6.0, $99{\sim}3,990{\mu}S/cm$, respectively, and the concentrations of dissolved major (up to 492 mg/l Ca; 83.8 mg/l Mg; 45.2 mg/l Na; 44.7 mg/l K, 50.8 mg/l Si) and trace elements (up to $826,060{\mu}g/l$ Fe; $131,230{\mu}g/l$ Mn; $333,600{\mu}g/l$ Al; $61,340{\mu}g/l$ Zn; $2,530{\mu}g/l$ Cu; $573{\mu}g/l$ Cd; $476{\mu}g/l$ Pb) were relatively high. The stream water showed the variation of dissolved metal concentrations in seasonally and spatially. The dissolved metal contents of the stream water increased by influx the leachate from the tailing disposal, but these of the down stream have been considerably decreased by mixing of dilute tributaries. The dissolved metal concentrations of the stream water at dry season (as February) were lower than these at rainy season (as May and July). These represent that the amounts of the leachate varied with season. However, stream water could not be effectively diluted by confluence with uncontaminated tributaries, because the flux of tributaries and streams reduced at dry season. Thus attenuations by dilution had been dominantly happened in rainy seasons. The order of accumulations of trace element in soils compared with background values revealed Mn>Fe>Pb>Cu>Zn. Sulfide minerals were mainly pyrrhotite, sphalerite and galena and chalcopyrite. Pyrrhotite was rapidly weathered along the edge and fractures, and results in the formation of Fe-(oxy)hydroxides, which absorbed a little amount of Zn.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.68-76
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• 2002

In this study, we have investigated the geochemical behavior and fate of heavy metals in acid rock drainage (ARD). The ARD was collected from the area of the former Dongrae pyrophyllite mine. The Dongrae Creek waters were strongly acidic (pH : 2.3~4.2) and contained high concentrations of $SO_4$, Al, Fe, Mn, Pb, Cu, Zn, and Cd, due to the influence of ARD generated from weathering of pyrite-rich pyrophyllite ores. However, the water quality gradually improved as the water flows downstream. In view of the change of mole fractions of dissolved Fe, Al and Mn, the generated ARD was initially both Fe- and AA-ich but progressively evolved to more Al-rich toward the confluence with the uncontaminated Suyoung River. As the AR3 (pH 2.3) mixed with the uncontaminated waters (pH 6.5), the pH increased up to 4.2, which caused precipitation of $SO_4$-rich Fe hydroxysulfate as a red-colored, massive ferricrete precipitate throughout the Dongrae Creek. Accompanying the precipitation of ferricrete, the Dongrae Creek water progressively changed to more Al-rich toward downstream sites. At the mouth of the Dongrae Creek, it (pH 3.4) mixed with the Suyoung River (pH 6.9), where pH increased to 5.7, causing precipitation of Al hydroxysulfate (white precipitates). Neutralization of the ARD-contaminated waters in the laboratory caused the successive formation of Fe precipitates at pH<3.5 and Al precipitates at higher pH (4~6). Manganese compounds were precipitated at pH>6. The removal of trace metals was dependent on the precipitation of these compounds, which acted as sorbents. The pHs for 50% sorption ($pH_{50}$) in Fe-rich and Al-rich waters were respectively 3.2 and 4.5 for Pb, 4.5 and 5.8 for Cu, 5.2 and 7.4 for Cd, and 5.8 and 7.0 for Zn. This indicates that the trace metals were sorbed preferentially with increasing pH in the general order of Pb, Cu, Cd, and Zn and that the sorption of trace metals in Al-rich water occurred at higher pH than those in Fe-rich water. The results of this study demonstrated that the partitioning of trace metals in ARD is not only a function of pH, but also depends on the chemical composition of the water.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1065-1075
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• 2015

In the estuary where the structure such as river-mouth weir has been installed, the flow is developed very complicatedly due to river water from upstream, tide of the sea and floodgate operation. Especially, if basin outlets more than one exists in one estuary, the boundary conditions will be significantly more complex form. Saemangeum(SMG) project area in Korea is the most typical example. There are Mankyung river and Dongjin river in upstream. The water of them inflows into SMG project area. In the downstream, river flow was drained from inland to sea over the SMG sea dike through the sluice. The connecting channel was located between Mankyung and Dongjin basins. It functions not only as transportation by ship in ordinary period but also as flood sharing by sending flood flow to each other in flood period. Therefore, in order to secure the safety against flood, it is very important to understand the flood sharing capacity for connecting channel. In this study, the flood control effect was analyzed using numerical simulation. Delft3D was used to numerical simulation and simulated period was set up with neap tide, in which the maximum flood stage occurred due to poor drainage. Actually, three connecting channels were designed in land use plan of the SMG Master Plan, but they were simplified to a single channel for conciseness of analysis in this study. According to the results of numerical analysis, the water level difference between two basins was increased and the maximum flood stage at dike sluice was also upraised depending on decrease of conveyance. And the velocity induced by same water level difference was decreased when the conveyance became smaller. In certain conveyance above, there was almost no flood control effect. Therefore, if the results of this study are considered for design of connecting channel, it will be expected to draw the optimal conveyance for minimizing dredging construction cost while maximizing the flood control effect.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.174-187
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• 2008

In an effort to identify structure and function of microbial loop in Paldang reservoir, we monitored environmental and biological factors at Kyungan stream (station K), Paldang dam (station P) and the confluence of North and South Han River (station M) from March to December, 2005. DOC concentration was higher in March to May and November than the others. Nutrient concentration in station K detected relatively higher than that of two stations. Both of phosphate and silicate gradually increased at all stations until September, after then decreased. The highest Chl-$\alpha$ concentration was observed at all stations in April, and November. The carbon biomass of bacteria and HNF were relatively higher in March, May and August than the others, whereas that of the ciliate showed no significant difference in monthly fluctuation. Nevertheless, the significant relationships revealed between ciliate (P<0.001) and HNF (P<0.05) and bacterial density. Tintinnopsis cratera, Didinium sp., Vorticella sp., Paramecium sp. and Strombidium sp. were dominant species in ciliate community. The dominant species of phytoplankton were Stephanodiscus hantzschii and Cyclotella meneghiniana at almost stations in Spring, Summer and Autumn. However, Aulacoseira granulata accounted for >95% of phytoplankton biomass at station P and M in Autumn. The carbon biomass of zooplankton was highest at station P and M in June, and relatively higher biomass observed at all stations in August, October and November. Diaphanosoma brachyurum and Bosmina longirostris were dominant in stations P and M of June and in all stations of October and November, respectively. The maximum growth (A. granulata: $0.17\;d^{-1}$, S. hantzschii: $0.14\;d^{-1}$) and grazing rate (A. granulata: 1.93 preys $d^{-1}$, S. hantzschii: 1.63 preys $d^{-1}$) of Bosmina longirostris revealed in algal preys as Aulacoseira granulata and Stephanodiscus hantzschii. In conclusion, these results suggest that bacteria and phytoplankton can play the most crucial source as prey within microbial food chain in Spring and Summer and grazing food chain in Autumn, respectively.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.137-146
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• 2006

The objective of this study was to examine the effect of donor cell types, the source of recipient oocytes and estrous synchronization on pregnancy and delivery rates of somatic cell nuclear transfer (SCNT) embryos in Korean native goats. Recipient oocytes were surgically collected after superovulation. Ear cells and fetal fibroblasts were collected and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. The zonae pellucidae of in vivo- and in vitro-matured oocytes were partially drilled using a laser system. Single somatic cell was transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3 M mannitol. After the fusion, embryos were activated by Ionomycin+6-DMAP. NT embryos were cultured in mSOF medium supplemented with 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $O_2$, 90% $N_2$ for 12 to 20 hr. One hundred and two SCNT embryos were transferred into 20 recipients and pregnancy rate at days 30 was 20.0%. Of them, one developed to term and delivered 1 kid. Ear cells showed significantly higher fusion (63.8 vs. 26.5%) and pregnancy rates (20.0 vs. 0.0%) than those of fetal fibroblast (p<0.05). The recipients synchronized by CIDR showed significantly lower pregnancy rates compared to that of recipient in natural estrus ($0.0{\sim}25.0%$ vs. 100%) (p<0.05). Cloned kid was born from the recipient in natural estrus. For the synchronization of estrus between recipient and donor, there was no difference between treatments (${\pm}0$ vs. +12 hr) in pregnancy rate. The first healthy cloned kid (Jinsoonny) was produced by transfer of SCNT embryos derived from in vivo oocytes and ear cells into a recipient goat whose estrus was synchronized with the donor. These results imply that donor cells for nuclear transfer may affect the success rate, and the estrus synchronization between donor and recipient animals can also be important.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.71-83
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• 2001

The purpose of this study was to Prove that the medial edge epithelial cells covering the secondary palatal shelves were removed by apoptosis during palatal fusion. 12 mature female rats (Suprague-Dawley) were mated overnight with male rats and sacrificed on days 15.0, 16.5, 16.75, 17.0 of pregnancy. The embryos were removed from the uterus and the heads were embedded in paraffin. The paraffin blocks were sectioned and the sections were undergone H-E staining for general histologic feature and TdT staining for detection of apoptotic cells. The obtained results were as follows. k. In the section of 16.0 and 16.5 day embryos, the palatal shelves were prior to contact and no apoptotic cells wereobserved in the medial edge epithelium. At the initial contact of Palatal shelves, there was a few apoptotic cells in the fusing epithelium. 2. In the 16.75 day embryos, the samples that epithelial seams did not lost there continuity, apoptotic cells were rarely seen at the midline epithelial seam. In contrast, a lot of apoptotic cells were observed at epithelial triangles and the junction between palatal shelves and nasal septum. 3. In the 16,75 day embryos, the samples that epithelial seams lost their continuity and disrupted to epithelial islands, large number, of apoptotic cells were observed at epithelial islands and epithelial triangles. Some apoptotic cells were also observed at the oral, nasal epithelium near the midline. 4. In the 17.0 day embryos, most of epithelial islands were disappeared and mesenchymal confluence was achieved. Apoptotic cells were rarely observed in the mesenchymal tissue which replaced epithelial islands, but there were some apoptotic cells at the epithelial triangles, oral and nasal epithelium. From the results of the study, it was revealed that medial edge epithelial cells of fusing palate were removed by apoptosis. Apoptotic cells were found mainly in the disappearing midline epithelial seam and the oral and nasal epithelial triangles at some late stages of palatal fusion.

• Journal of the Korean Geographical Society
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• v.50 no.6
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• pp.571-605
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• 2015

This research revealed that 'Yipjiamlyu' in the Mukedeng's map is geographically 'a beginning point of underf low,' whose location is on the Heishigou's riverbed(E.L. 1,840m) in the NNE side of Daegakbong peak, and that 'Tomungangweon'(Heishigou) is one of the upstream reach of the Sungari River, which, according to historical documents and my fieldwork, Mukedeng also knew at the time of Yimjin(1712) Boundary Making and Demarcation(YBMD). These findings suggest the need to reinterpret the processes of YBMD. Mukedeng set up the Baekdusanjeonggyeobi on the mistaken assumptions on the linkage of 'Yipjiamlyu' and Tumen River. It should have been set up on the Daeyeonjibong peak. Mukedeng found the 'Yipjiamlyu' on the riverbed of 'Tomungangweon'(Heishigou), went downstream, and realized that this river did not flow into the Tumen River. During the search for the source of Tumen River, he found a water stream, and regarded it as the source of Tumen River. He speculated that the water at the 'Yipjiamlyu' flows through the underground to reappear at the his 'identified' source of Tumen River. Consequently, he adjured the construction of demarcation from Baekdusanjeonggyeobi through 'Yipjiamlyu' to the his 'identified' source of Tumen River. The water stream pointed as the source of Tumen River, however, was not part of the upstream reach of Tumen River. Actually, Korean officials, who were in charge of establishing boundary features, set up the demarcation from Baekdusanjeonggyeobi through Huanghuasongdianzi to the true source of Tumen River identified by themselves, which Mukedeng had not intended. The ambiguity of the location of 'Yipjiamlyu' caused a difference between Mukedeng's original request and Korean officials' implementation in the boundary demarcation. Throughout the whole processes of YBMD, Korea(Joseon) and China(Qing) both mistook the real geography of the river system. Their understanding on Yalu River system was correct. But the identification of the spring source of the Tumen River by Korean participants was the only geographically correct result related on this river system in YBMD.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.15-30
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• 1998

Physical geography is the discipline which deals with the relationship between man and natural environment. Therefore, it should be studied as the organized unity. In this paper I recognize the drainage basin as a framework outlining physical geography, describe the difference of inhabitant's life style due to the difference of natural environment in the drainage basin, and consider the meaning of drainage basin as a unit of life(and unit of regional geography). Munkyung is divided into three regions(intermontane basin region, middle mountainous region, marginal hilly region of the great basin) owing to the topographic characteristics. Subdivision in these regions is related closely to drainage network distribution, specially in intermontane basin region. And small regions have developed with the confluence point of $3{\sim}4$ order streams as the central figure. Intermontane basin region is the valley floor of Sinbuk-Soya-Kauun-Nongam stream located in the limestone region which is exposed according to Munkyung fault at its northern part. Small streams are affected strongly by the influence of the NNE-SSE or WNW-ESE tectolineament. Thus Kaeripryungro(鷄立嶺路), Saejaegil(새재길), Ewharyungro(伊火嶺路) and so on are constructed through the tectolineament. In the valley floors of small streams which flow into the intermontane basin, there are large floodplains. Floodplain in Sinbuk, Joryung, and Yangsan stream is used to paddy field or orchard, and in Nongam stream is used to paddy field or vegetable field. Hills are distributed largely in the periphery of intermontane basin. Limestone hills in Kauun and Masung basin are not continuous to the present low and flat floodplain, and most of those are used to forest land and field. On the other side. granite hills in Koyori are continuous to be used to the present floodplain, and they are used to residential area and field. In the middle mountainous region are there hilly mountains constructed in the geology of Palaeozoic Pyeongan System in northern area and Chosun System's Limestone Series in southern area, and banded gneiss and schist among Sobaeksan Gneiss Complex. In Palaeozoic Pyeongan System region are there relatively rugged mountains and ingrown meanders developed along tectolineaments. Chosun System's Limestone Series region builds up a geomorphic surface, develops various karst landforms. Mountainous area is used to field. On the other hand, especially in case of Hogye, valley bottom is wide, long, and discontinuous to slope, is used to paddy field dominantly. And schist region in Youngnam Block of Pre-Cambrian is rugged mountainous. Marginal hilly region of the great basin is hilly zone located in the margin of erosional basin(Bonghwa-Youngju-Yechon-Hamchang-Sangju). This region is lower geomorphic surface which is consisted of hills of $50{\sim}100$m height. Hills are used to field or orchard, and dissected gentle depression is used to paddy field.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.127-132
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• 2004

This study was conducted to examine the effects of electric stimulation conditions on in vitro developmental ability of caprine embryos after somatic cell nuclear transfer. Recipient oocytes were surgically collected after superovulation by using CIDR and FSH, PMSG, hCG and estrous synchronization in Korean native goats. The caprine ear cells were cultured in vitro in serum-starvation condition (TCM-l99 + 0.5% FBS) for 3 to 5 days of cell confluence. The zona pellucida of in vivo and in vitro matured oocytes were partially drilled using laser system. Single somatic cell was individually transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3M mannitol. After the electofusion, embryos were activated by electric stimulation or Ionomycin + 6-DMAP. Nuclear transfer embryos were cultured in mSOF medium supplemented with 0.8% BSA 6∼7 days at 39 , 5% $CO_2$, 5% $O_2$, 90% $N_2$. The fusion rate of donor cells was 60.4% and 40.3 % in ear cell and fetal fibroblast, and cleavage rate were 40.6% and 48.2%, respectively. No significant difference was found in the fusion and cleavage rate in different donor cells. Nuclear transferred oocytes were fused by electric pulses of 1.30∼1.40, 2.30∼2.39 and 2.40∼2.46 ㎸/cm. There was no significant difference among different electric pulses in fusion rates (26.7, 34.8 and 43.8%). The cleavage rate was higher (p<0.05) in 1.30∼1.40 ㎸/cm (82.9%) than 2.30∼2.39 ㎸/cm (43.8%) and 2.40∼2.46 ㎸/cm. (51.8%). The fusion rates of recipient oocyte source were 1st (43.5% and 23.6%), 2nd (55.7％ and 39.2%) and 3rd (66.1% and 52.8%) in in vivo and in vitro oocytes. However, fusion ratee were significantly higher (p<0.05) in in vivo than in vitro oocyte. The cleavage rate of fused oocytes from in vivo and in vitro sources were 52.6% and 54.4%, respectively. No significant difference was found in the cleavage rate according to the recipient oocyte source. These results suggest that factors such as field pulse of electric stimulation and oocyte source could affect in vitro developmental ability of nuclear transplanted caprine oocytes.

• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.26-36
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• 2011

Objectives: In the present study, three kinds of tissues cells (pulp, gingiva, and periodontal ligament) were investigated if those cells express MMP and TIMP when they were stimulated with neuropeptides (substance P, CGRP) or proinflammatory cytokine, TNF-$\alpha$. Materials and Methods: The cells cultured from human dental pulp (PF), gingiva (GF) and periodontal ligament were (PDLF) stimulated with Mock, SP, TNF-$\alpha$, and CGRP for 24 hrs and 48 hrs. for an RNase protection assay and Enzyme Linked Immunosorbent Assay. Cells (PF, GF and PDLF) seeded in 100 mm culture dish were stimulated with SP ($10^{-5}$, $10^{-8}\;M$) or only with medium (Mock stimulation) for 4hrs and for 24 hrs for RNase Protection Assay, and they were stimulated with CGRP ($10^{-5}\;M$) and TNF-$\alpha$(2 ng/mL) for 24 hrs and with various concentraion of TNF-$\alpha$(2, 10, and 100 ng/mL) for Rnase Protection Assay with a human MMP-1 probe set including MMP 1, 2, 8, 7, 8, 9, 12, and TIMP 2, 3. In addition, cells (PF, GF and PDLF) were stimulated with Mock and various concentraion of TNF-$\alpha$(2, 10, and 100 ng/mL) for 24 hrs and with TNF-$\alpha$(10 ng/mL) for 48 hrs, and the supernatents from the cells were collected for Enzyme Linked Immunosorbent Assay (ELISA) for MMP-1 and MMP-13. Results: The expression of MMPs in PF, GF, PDLF after stimulation with SP and CGRP were not changed compared with Mock stimulation for 4 hrs and 24 hrs. The expression of MMP-1, -12, -13 24 hrs after stimulation with TNF-$\alpha$ were upregulated, however the expression of TIMP-3 in PF, GF, PDLF after stimulation with TNF-$\alpha$ were downregulated. TNF-$\alpha$(2 ng/mL, 10 ng/mL, 100 ng/mL) increased MMP-1 and MMP-12 expression in PF dose dependently for 24 hrs. Conclusions: TNF-$\alpha$ in the area of inflammation may play an important role in regulating the remodeling of dentin, cementum, and alveolar bone.