• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.201-213
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• 2003

The adsorption property and ability of domestic zeolites for some heavy metal ions (Ag, Pb, Cr, Cu, Zn, Mn), which may cause a serious environmental problem in industrial wastewater, were evaluated on ore unit through a series of adsorption experiments together with careful examinations of mineral composition and properties of the zeolites. Though the adsorption behavior basically took place in the form of a cation exchange reaction, the higher CEC value does not necessarily to imply the higher adsorption capacity for a specific heavy metal. A general trend of the adsorption selectivity for heavy metals in the zeolites is determined to be as follow: $Ag\geq$Pb>Cr,Cu$\geq$Zn>Mn, but the adsorption properties of heavy metal ions somewhat depend on the species and composition of zeolite. Clinoptilolite tends to adsorb selectively Cu in case of Cr and Cu, whereas heulandite prefers Cr to Cu. A dominant adsorption selectivity of the zeolite ores for Ag and Pb is generally conspicuous regardless of their zeolite species and composition. The zeolite ores exhibit a preferential adsorption especially for $Ag^{+}$ so as not to regenerate when treated with $Na^{+}$ . In the adsorption capacity for heavy meta ions, the zeolites differ in great depending on their species: ferrierite>clinoptilolite>heulandite. Considering the CEC value of mordenite, the mordenite-rich ore appears to be similar to the clinoptilolite ore in the adsorption capacity. The adsorption capacity for heavy metals is not positively proportional to the CEC values of the zeolites measured by the exchange reaction with ammonium ion. In addition, the adsorption capacity roughly tends to depend on the zeolite contents, i.e., the grade of zeolite ore, but the trend is not consistent at all in some ores. These may be caused by the adsorption selectivity for some specific heavy metals, the presence of possible stacking micro-faults and natural cations such as K hardly to exchange in the zeolite. Considering the economic availability and functional effectiveness as natural zeolite resources, clinoptilolite ores could be applicable to utilize the domestic zeolites for the removal of heavy metals.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.3
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• pp.179-186
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• 1998

This experiment was conducted to study on forage utility of Diplachne fusca L. which live in reclaimed saline land of midwest region of Korea The secondary experiment was conducted to know on growth characteristics, forage yield and forage value of Diplachne fusca L. in order to get a necessary data on possible utilization of native plant as a forage crop and practical use of reclaimed saline land. The results obtained are summarized as follows; 1. The growth of Diplachne fusca L. was neary finished at heading stage. So plant height, leaf length, leaf width, stem diameter, tillering number, fresh weight and dry weight per plant were 137.5cm, 42.6cm, 4.65mm, 2.48mm, 15.3 tiller, 44.68 and 15.3g respectively. 2. Fresh weight was the highest with 4,460kg/10a at heading stage, dry weight was 1,530kg/10a at heading stage and 1,630kg/10a at 20 day after heading. The fresh weight was significantly difference between cutting height level according to cutting time, but total fresh weight was not significantly difference between cutting height level. Total dry weight was significantly difference between cutting height, so it was a large yield at cutting height of 10cm. 3. The contents of crude protein, available protein, digestible protein and TDN were the range of 12.3~3.7%, 12.3~3.7% 10.8~3.6% and 65.2~60.7% according to growth stage, respectively. The highest yield of crude protein, available protein, and digestible protein were showed at heading stage, that of TDN showed at 20 day after heading. The contents of ADF and NDF were the range of 36.4~50.0% and 62.7-80.5% according to growth stage. 4. The contents of P, Ca, K and Mg were the range of 0.31~0.20, 0.70~0.52, 1.74~1.28 and 0.19~0.18% according to growth stage, respectively. The highest yield of P, Ca and K was showed at heading stage, that of Mg showed at 20 day after heading. 5. The contents of ENE, NEL, NEM and NEG were the range of 1.42~1.29, 0.68~0.62, 0.68~0.61 and 0.40~0.35 McaVlb according to growth stage, respectively. The highest yield of ENE, NEL, NEM and NEG was showed at 20 day after heading by inuease after heading. 6. The grasseating ratio of Diplachne fusca L. of before and after heading by milk cattle was 96.5% and 95.3%, respectively.

• Journal of the Korean Geographical Society
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• v.28 no.4
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• pp.312-320
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• 1993

Along with the fade out of the Cold War the world is undergoing a fundamental restructuring. The process is generally refered to regionalization and globalization. In this context, the Paper presents a geopolitical perspective on the future of Northeast Asia. To meet the global trend, it is expected that the countries in the area organize an economically cooperative unity, the concept of which the author calls the northeast Asian Rim (NEAR). With its huge potentials to become the largest economic area in the world and with its rather complicated historical and social background, the Rim is tentatively supposed to have a loose and soft organization, to be flexible in dealing with the intra-and interregional relations. The idea underlying the view is that the former area of confrontation between the land power and the sea power is, under the new world environment, going to recover its proper locational attributes and develop into a merging area, a new core. As a physical framework of the Rim a spatial structurc is assumed to consist of two-subrims and two development axes with four development centers.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.257-261
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• 1998

The repeated subcultures of in vitro plant materials in wasabi became highly vitrified and the capacity for multiple shoot formation from the vitrified plant materials was very low. In order to improve the quality of in vitro propagated planting materials, the experiments were carried out using culture vessels capped with membrane filter(MF). When vitrified shoots were cultured on MS medium with 0.2mg/L BA in the vessels with MF or without MF for 60 days, the shoots in the vessels with MF did not vitrified. In contrast, the shoots grown in the vessels without MF vitrified at 65%. The stomates of vitrified leaves were circular and inflated, whereas those of normal leaves acclimatizated in the vessels with MF were ovate in shape. The hardened shoots were also cultured on MS media without sucrose containing 0.01mg/L IBA in vessels with(photoautotrophic culture) or without(control) MF. Sucrose was necessary for survival of the in vitro plantlets in the vessels without MF. After 20 days of culture, the shoots in the vessels without MF on the sucrose-free media turned yellow and died. But the shoots in the vessels with MF in the sucrose-free media produced a lot of roots. When shoots were cultured on MS medium with 2% sucrose containing 0.01mg/L IBA in the vessels with(photomixotrophic culture) or without(heterotrophic culture) MF, best growth occured in photomixotrophic culture.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.666-671
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• 2012

Gas hydrates are inclusion compounds formed when small-sized guest molecules are incorporated into the well defined cages made up of hydrogen bonded water molecules. Since large masses of natural gas hydrates exist in permafrost regions or beneath deep oceans, these naturally occurring gas hydrates in the earth containing mostly $CH_4$ are regarded as future energy resources. The heat of dissociation is one of the most important thermal properties in exploiting natural gas hydrates. The accurate and direct method to measure the dissociation enthalpies of gas hydrates is to use a calorimeter. In this study, the high pressure micro DSC (Differential Scanning Calorimeter) was used to measure the dissociation enthalpies of methane, ethane, and propane hydrates. The accuracy and repeatability of the data obtained from the DSC was confirmed by measuring the dissociation enthalpy of ice. The dissociation enthalpies of methane, ethane, and propane hydrates were found to be 54.2, 73.8, and 127.7 kJ/mol-gas, respectively. For each gas hydrate, at given pressures the dissociation temperatures which were obtained in the process of enthalpy measurement were compared with three-phase (hydrate (H) - liquid water (Lw) - vapor (V)) equilibrium data in the literature and found to be in good agreement with literature values.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.665-673
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• 2011

In order to estimate the hydrocarbon reserves, the porosity of the reservoir must be determined. The porosity of the area without a well is generally calculated by extrapolating the porosity logs measured at wells. However, if not only well logs but also seismic data exist on the same site, the more accurate pseudo porosity log can be obtained through artificial neural network technique by extracting the relations between the seismic data and well logs at the site. In this study, we have developed a module which creates pseudo porosity logs by using the polynomial neural network method. In order to obtain more accurate pseudo porosity logs, we selected the seismic attributes which have high correlation values in the correlation analysis between the seismic attributes and the porosity logs. Through the training procedure between selected seismic attributes and well logs, our module produces the correlation weights which can be used to generate the pseudo porosity log in the well free area. To verify the reliability and the applicability of the developed module, we have applied the module to the field data acquired from F3 Block in the North Sea and compared the results to those from the probabilistic neural network method in a commercial program. We could confirm the reliability of our module because both results showed similar trend. Moreover, since the pseudo porosity logs from polynomial neural network method are closer to the true porosity logs at the wells than those from probabilistic method, we concluded that the polynomial neural network method is effective for the data sets with insufficient wells such as F3 Block in the North Sea.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.73-84
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• 2010

Gold and silver deposits within the Eunjeok and Sangeun mines are located in Yeongam district, Cheollanamdo-province. They are composed of vein ore bodies infilling the fractures of Cretaceous rhyolitic tuff. The Eunjeok mine have three gold and silver bearing hydrothermal veins which is infilling the fracture of rhyolitic tuff. Major ore minerals within the Eunjeok and Sangeun mines are arsenopyrite, pyrite, chalcopyrite, sphalerite and galena and minor ores are electrum, native silver and argentite. Sericitization is dominant in alteration zone and chloritization and dickitization is minor. Quartz veins in the Eunjeok and Sangeun mine have the similar paragenesis and vein textures such like breccia, crustiform, comb and vuggy morphology indicating the formation of typical epithermal environment. In order to carry out the preliminary feasibility study of mine according to the commodity and elucidate the occurrence features of mineral resources from Eunjeok and Sangeun mine, common commodity (Pb, Zn, Cu, Fe, Mo, W, Au and U), and industrial commodity (In, Re, Ga, Ge, Se, Te, Y, Eu and Sm) for 17 ore specimen were analyzed. It is tentatively thought that there is no exploitable mine for iron, lead, zinc, copper, tungsten and uranium based on the preliminary result. If the reserves are secured through the detailed prospecting in case of molybdenum and silver, it is tentatively thought that there will be exploitable deposits depending on international metal price. If we assume the vein width from 0.25 m to 2 m including alteration zone with the gold grade of 80g/t, it is inferred that the resources amount of the Eunjeok-Sangeun mines range from 6.5 to 65ton. However, as the vein structure of the Eunjeok and Sangeun mines is developed together with alteration zone, it should be estimated to include potential alteration zone in order to yield the average grade. It is needed to carry out more exploration in the near future because the reserves can be flexibly estimated according to the change of average grade considering the alteration zone.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.131-150
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• 1991

The Weolseong diatreme was temporally and spatially related to the intrusion of the Gadaeri granite, and was -mineralized by meteoric aqueous fluids. In the Nokdong As-Zn deposit, pyrite, aresenopyrite and sphalerite are the most abundant sulfide minerals. They are associated with minor amount of magnetite, pyrrhotite, chalcopyrite and cassiterite, and trace amounts of Pb-Sb-Bi-Ag sulphosalts. The AsZn ore probably occurred at about $350^{\circ}C$ according to fluid inclusion and compositional data estimated from the arsenic content of arsenopyrite and iron content of sphalerite intergrown with pyrrhotite + chalcopyrite + cubanite. Heating studies of fluid inclusions in quartz indicate a temperature range between 180 and $360^{\circ}C$, and freezing data indicate a salinity range from 0.8 to 4.1 eq.wt % NaCl. The coexisting assemblage pyrite + pyrrhotite + arsenopyrite suggests that $H_2S$ was the dominate reduced sulfur species, and defines fluid parameter thus: $10^{-34.5}$ < ${\alpha}_{S_2}$ < $10^{-33}$, $10^{-11}$ < $f_{S_2}$ < $10^{-8}$, -2.4 < ${\alpha}_{S_2}$ < -1.6 atm and pH= 5.2 (sericte stable) at $300^{\circ}C$. The sulfur isotope values ranged from 1.8 to 5.5% and indicate that the sulfur in the sulfides is of magmatic in origin. The carbon isotope values range from -7.8 to -11.6%, and the oxygen isotope values from the carbonates in mineralized wall rock range from 2 to 11.4%. The oxygen isotope compositions of water coexisting with calcite require an input of meteoric water. The geochemical data indicate that the ore-forming fluid probably was generated by a variety of mechanisms, including deep circulation of meteoric water driven by magmatic heat, with possible input of magniatic water and ore component.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.305-310
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• 2001

The purpose of this study is to calculate delay damages for contractors. The study has been performed by investigation of delay cost occurrence status and the analysis of subway construction cases. The results of this study are as follows: 1. Delay cost( 1day) equivalent to $0.005\%$ of total construction cost by analysis case studies. 2. Including bank interest, dealy cost is analysed as the following; $1.1\~9.2\%$ of total construction cost in part extension period, $3.3\~11.0\%$ of total construction cost in total extension period. 3. In comparison between liquidated damages and delay cost, liquidated damages account for average 20.1 times of delay costs. 4. Acceleration cost will be calculate on the basis of delay cost calculation method. In the result of this method, acceleration cost is equal to delay cost at least or must be large than delay cost