• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.243-257
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• 2002

Ca-type and Na-type bentonites show the great difference of some physicochemical properties. Na exchanged bentonite is mainly used for the foundry and construction materials in domestic utilization. This study tries to identify in detail the differences of some physicochemical properties and thermal properties between Ca-type and Na-type bentonites. Also the adsorption behavior and interlayer expansion for the HDTMA (Hexadecyltrimethylammonium) exchanged and CP (Cetylprydinium) exchanged Ca-type and Na-type bentonites were compared. Na-type bentonite shows the strong alkaline property, high viscosity and swelling compared to Ca-type bentonite. However, two types are very similar for the cation exchange capacity and MB (Methylene Blue) adsorption. The decomposition of adsorbed and interlayer water of Na-type bentonite is caused in the lower temperature than Ca-type bentonite. And Ca-type bentonite shows the decomposition of structural water in the lower temperature than Na-type bentonite. The interlayer expansion of montmorillonite resulted to the intercalation of HDTMA and CP into bentonite is so strongly caused from 12～15 $\AA$ to $40\AA$ (basal spacing). HDTMA-bentonite is almost expanded to $37～38\AA$ when 200% CEC equivalent amount of HDTMA is added, and CP-bentonite is fullly expanded to 40 $\AA$ in the 140% CEC equivalent amount of CP It means that CP causes the stronger interlayer expansion of montmorillonite and easier adsorption than HDTMA. Adsorption behaviors of CP into bentonite is so stable and continuously sorbed in the proportion to the treatment of amount until 200% of the CEC equivalents. CP-bentonite shows the same adsorption behavior regardless of Ca-type or Na-type montmorillonite.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.1-16
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• 2003

Geochemical characteristics of groundwater in the different kinds of various lithology such as Haman formation, Panyaweol formation, Jusan andesitic formation and Palgongsan granite is distinguished by mineralogical and chemical compositions. The Concentration of the majority of solutes in groundwaters of Haman and Panyaweol formation is higher than in that of andesite and granite. Higher concentration of $HCO_3^{-}{\;}and{\;}SO_4^{2-}$ anions in the groundwater is peculiar. High concentrations of $Ca^{2+},{\;}Mg^{2+},{\;}HCO_3^{-}$ in the groundwaters of the sedimentary rocks result mainly from reaction of $CO^{2-}$ charged water with calcite and weathered feldspars. With the Piper diagram, the groundwaters of Haman formations are mainly plotted in $CaSO_4-CaCl_2$ type, whereas those of Panyaweol formations are plotted in the bothside of $Ca(HCO_3)_2{\;}and{\;}CaSO_4-CaCl_2$ type. Thses two different types of $Ca(HCO_3)_2{\;}and{\;}CaSO_4-CaCl_2$ groundwater were originated from dissolution of calcite($Ca(HCO_3)_2)$ and the oxidation of pyrite($CaSO_4-CaCl_2$), respectively. And it also is influenced by anthropogenic contamination. Three factors were extracted from the factor analysis for chemical data. Factor 1, controlled by $SO_4^{2-},{\;}Na^{+},{\;}Ca^{2+}$ and Fe, explains the dissolution of calcite, plagioclase and oxidation of pyrite. Factor 2, controlled by $HCO_3^{-}{\;}and{\;}Mg^{2+}$, mainly explains the dissolution of Mg-carbonates and dolomitization. Factor 3, controlled by $Cl^{-},{\;}K^{+}{\;}and{\;}NO_3^{-}$, is subject to the influence of artificial pollution including industrial waste water disposal. In this study area, some industrial complex which is close to Keumho river show the higher score of factor 3.

• Applied Microscopy
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• v.19 no.2
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• pp.119-137
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• 1989

It has been shown in this and earlier investigation that the turtle bladder mucosa has three main cell types on their mucosal surface. They are the granular cells, ${\alpha}$ CA cells, and ${\beta}$ CA cells. The three major transport mechanisms that occurs in the turtle bladder are sodium reabsorption, proton secretion, and bicarbonate secretion. In the present work the trans-port mechanisms by bladder epithelial cells of freshwater turtle, Pseudemys scripta, are summarized as follows. 1. The granular cells play an important role in sodium transport, while the ${\alpha}$ and ${\beta}$ CA cells do not appear to play a determining role in sodium transport. 2. It appears that the active sodium transport in the granular cells occurs in two-step process, implying that first, sodium diffuses into the cells, followed by an energy-dependent efflux step, which is catalyzed by the ouabain-sensitive Na-K ATPase. 3. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pump on the apical plasma membrane, while the ${\beta}$ type of CA cells are believed to be responsible for bicarbonate secretion. 4. When looked at under freeze-fracture electron microscopy, the apical plasma membrane of ${\alpha}$ cells have a characteristic population of rod-shaped intramembranous particles which are believed to be components of the proton pumps. Conversely, ${\beta}$ type of CA cells show rod-shaped particles in their basolateral plasma membranes, which is consistent with the proton absorptive, bicarbonate secretory mechanism. 5. In the turtle bladder, the ${\alpha}$ and ${\beta}$ type of cells are believed to be both responsible for proton transport, but in opposite directions.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.3
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• pp.162-170
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• 1998

Geochemical characteristics of groundwater in Goryeong area, based on chemical analyses of 34 water samples and mineralogical study of rocks, differ among Nagdong, Hasandong and Jinju formations and Goryeong granite in relation to mineralogical compositions of the rocks. Concentrations of most solutes are higher in groundwater of the sedimentary formations than in that of granite. Ca$\^$2＋/ in the sedimentary groundwaters results mainly from reaction of CO$_2$-charged water with calcite and weathered plagioclase. Average groundwater in the Jinju formation is oversaturated with respect to calcite. Major types of groundwaters are hard Ca(HCO$_3$)$_2$ and CaSO$_4$with hardness of 155 mg/1 for Nagdong formation, 150 mg/1 for Hasandong formation and 140 mg/1 for Jinju formation whereas it is soft Ca(HCO$_3$)$_2$with hardness of 90 mg/1 for Goryeong granite. Ca(HCO$_3$)$_2$type resole from dissolution of calcite and plagiodase while CaSO$_4$type results from dissolution of pyrite and partly from domestic pollutants. CaSO$_4$type may indicate that the sedimentary groundwaters are more evolved geochemically than the granitic groundwater, but it is not obvious because the type might be affected by the dissolution of pyrite and domestic pollutions. Prite is expected to occur as a stable sulfide in the gray∼dark gray arkosic sandstones formed under reducing environment.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.2
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• pp.73-88
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• 2000

The geochemistry of the $CO_2$-rich waters ($Pco_2\leq$about 1 atm) in NE part of the Kangwon province was investigated. The $CO_2$-rich waters can be divided to three types based on chemical compositions: Na-$HCO_3$, Ca-Na-$HCO_3$and Ca-$HCO_3$types. The water chemistry indicates that these type waters were evolved through reaction with host rocks by supply of deep-seated $CO_2$during deep circulation, and their geochemical environments in depth might have been different each other. The dissolution process of plagioclase is important in water/granite interactions and its solubility change according to reaction temperature played an important role in the determination of chemical compositions. The higher reaction temperature coincides with the lower different in solubility between albite and anorthite. It means that calcium is mainly released to the water in the lower temperature, whereas sodium in the higher temperature due to high Na/Ca ratio in plagioclase. The application of various chemical geothermometries on the $CO_2$-rich waters shows that the calculated reservoir temperature of Na-$HCO_3$type (about 15$0^{\circ}C$) is higher than those of Ca-$HCO_3$type. Therefore, we now interpret the recognized chemical difference was mainly due to the difference of reaction temperature. Considering normal thermal gradient, we can understand that the Na-$HCO_3$type was evolved from deeper crustal depth than the Ca-$HCO_3$type.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.76-84
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• 1998

In this paper, CSMA/CA with bridging is analyzed which is an added function of relaying directly between access points when wireless terminals can not communicate each other, and is also compared to the CSMA/CA without bridging which is IEEE 802.11 MAC standard. Through simulations, it is shown that the two methods have the similar performance in terms of the throughput but the bridging CSMA/CA improves the delay compared to the non-bridging CSMA/CA.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.383-389
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• 2018

Recently, it has been reported that water pollution due to non-point pollutants continues. Studies have been actively carried out to prevent such non-point pollutants from flowing into the water system and to prevent water pollution. In this study, to evaluate the adequate design of the LID facilities the rainfall corresponding to 80% of the cumulative rainfall of Yongin city was applied to an SA / CA graph obtained from the analysis of monitoring results of the vegetation type LID facility. As a result, the appropriate SA/CA ratio was 0.6% for stormwater sustain efficiency 80% and the appropriate SA/CA ratio was 0.5% for TSS removal efficiency 80%. The appropriate SA/CA ratio of the vegetation type LID proposed in this study can be used as a basis. for the future vegetation type LID design. If more data of vegetation type LID are added through continuous research, it will be more accurate.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.3
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• pp.116-124
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• 2000

Geochemical and isotopic analyses were carried out to investigate hydrochemical characteristics, source of carbon species in the carbonated waters in South Korea. Most Korean carbonated waters from different geologic settings are characterized by a Ca-HCO$_3$type with a relatively low pH range from 5.3 to 6.3 (avg. 6.0). The concentrations of cations and anions in the carbonate waters are in the order of Ca$^{2＋}$>Na$^{＋}$>Mg$^{2＋}$>Si$^{4＋}$>Fe$^{2＋}$>K$^{＋}$ and HCO$_3$$^{－}$>SO$_4$$^{2－}$>Cl$^{－}$, respectively. The HCO$_3$$^{－}$ ion is more enriched in the carbonated water from the sedimentary rock and granitic rock of Mesozoic age in the Gyungsang basin(GII) and the Precambrian metamorphic rock and Jurassic granitic rocks of the Gyunggj massif in the Gangwon province(GⅠ) than those of the meta-sedimentary rock and granite in the Ogcheon zone(GⅢ). Based on the oxygen and hydrogen isotopic data, the carbonated waters are derived from the meteoric water, showing apparent latitude and altitude effects. The $delta$$^{13}$C values of carbon species in the carbonated water are in between -6.23 and 0.0 $textperthousand$, suggesting inorganic source of carbon originated from the carbonate mineral and carbonate rock in the aquifer.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.520-523
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• 2003

강원도 지역의 대표적인 탄산용출수에 대한 수리지구화학적 연구를 통하여 심부 지열 저장지의 온도와 심부환경을 추정하였다. 탄산용출수는 공통적으로 약산성의 pH와 높은 이온함량으로 특징되지만, 화학적으로는 Na-HCO$_3$형, Ca-Na-HCO$_3$형, 그리고 Ca-HCO$_3$형으로 뚜렷이 구분된다. 심부에서 생성된 탄산용출수가 지표로 상승하는 도중에 수반된 지표수 혼합차이로 인해 이런 화학조성의 차이가 유발된 것으로 판단된다. Na-HCO$_3$형 탄산수는 화학 조성상 ‘mature water’의 특징을 보여주는 반면, 다른 두 유형의 탄산수들은 ‘immature water’에 해당하였다. Na-HCO$_3$ 형 탄산수에 대하여 실리카, Na-K 및 Na-K-Ca 지온계를 적용한 결과, 약 l15-157도의 심부저장지 온도가 산출되었으며, 이 결과는 다성분 평형계를 이용한 추정 온도 (약 140-160도)와도 잘 일치하였다. 반면, Ca-HCO$_3$ 형 탄산수들은 지표수와의 혼합 때문에 상대적으로 낮고 넓은 범위의 추정 온도 (약 60-130도)를 나타내었다. 따라서 연구지역 내 탄산용출수의 심부저장지 온도는 Na-HCO$_3$형에 대해서만 타당하게 적용될 수 있으며, 약 140-160도일 것으로 추정된다.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.13-23
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• 2002

The chemical compositions of groundwaters from the granite areas mainly belong to Ca-HC0$_{3}$ and Na-HC0$_{3}$type, and some of these belong to Ca-(CI+S0$_{4}$) and Na-(CI+S0$_{4}$) type. Spring waters and groundwaters from anorthosite areas belong to Ca-HC03 and Na-HC03 type, respectively. The result of reaction path modeling shows that the chemical compositions of aqueous solution reacted with granite evolve from initial Ca-CI type, via CaHC0$_{3}$ type, to Na-HC0$_{3}$ type. The result of rain water-anorthosite interaction is similar to evolution path of granite reaction and both of these results agree well with the field data. In the reaction path modeling of rain watergranite/anorthosite reaction, as a reaction is progressing, the activity of hydrogen ion decreases (pH increases). The concentrations of cations are controlled by the dissolution of rock-forming minerals and precipitation and re-dissolution of secondary minerals according to the pH. The continuous addition of granite causes the formation of secondary minerals in the following sequence; gibbsite plus hematite, Mn-oxide, kaolinite, silica, chlorite, muscovite (a proxy for illite here), calcite, laumontite, prehnite, and finally analcime. In the anorthosite reaction, the order of precipitation of secondary minerals is the same as with granite reaction except that there is no silica precipitation and paragonite precipitates instead of analcime. The silica and kaolinite are predominant minerals in the granite and anorthosite reactions, respectively. Total quantities of secondary minerals in the anorthosite reaction are more abundant than those in the granite reaction.