• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.407-413
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• 1998

The influence of the anion composition of simulated acid rain on cation leaching of two soils with different surface charge properties was examined. Four mixtures of mole ratio of $SO_4:NO_3$(1:0, 2:1, 1:1, 0:1) with pH 2.0 simulated acid rain were applied to an Inceptisols(Gyuam series) and Andisols(Pyeongdae series). The Andisols had higher $SO_4{^{2-}}$ adsorption capacity than the Inceptisols because of its higher point of zero charge(PZC, pH 6.5) than Inceptisols(PZC pH 3.1). Cation leaching in Andisols varied directly with the $NO_3$ content of the leaching input due to higher mobility of $NO_3$ compared with $SO_4$ that was absorbed. The pH of the Andisols was higher with the addition of $Na_2SO_4$ than the addition of $NaNO_3$ indicating that this soil behaves as a base and has a high $SO_4$ adsorption capacity. The relative $NO_3{^-}/SO_4{^{2-}}$ content input had no effect on cation leaching of the Inceptisols. Amounts of leaching on the Andisols by simulated acid rain were higher than Inceptisols. This experiment explained that anion composition of acid rain plays a significant role in the cation leaching of soils which are able to adsorb $SO_4$.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.147-157
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• 2004

The production of $^{14}C$ occurs in the Moderator(MOD), Primary Heat Transport System (PHTS), Annulus Gas System(AGS) and Fuel in the CANDU reactor. Among the four systems, The MOD system is the largest contributor to $^{14}C$ production(approximately 94.8%). $^{14}C$ is distributed of $^{14}CO_2$, $H_2^{14}CO_3$, $H^{14}{CO_3}^-$ and $^{14}{CO_3}^{2-}$ species as a function of the pH of water. Of these species, $H_2^{14}CO_3$ and $H^{14}{CO_3}^-$ form are predominant because the pH of MOD system is ＞ 5. In this paper, adsorption-desorption characteristics of bicarbonate ion (${HCO_3}^-$) by IRN 150 resin was investigated. ${HCO_3}^-$ ion existed in neutral condition(app. pH 7)was reacted with ion exchange resin (IRN-150) and saturated with it. Then $NaNO_3$ and $Na_3PO_4$ solutions selected as extraction materials were used to make an investigation into feasibility of ${HCO_3}^-$ extraction from resin saturated with ${HCO_3}^-$. Desorption of $CO^{2+}$ and $Cs^+$ ion by $Na^+$ ion was not occurred, and desorption of ${HCO_3}^-$ ion by ${NO_3}^-$ and ${PO_4}^{3-}$ was occurred slowly. Also, the status of ion exchange which is used in Wolsong NPPs and generation of spent resin yearly were surveyed.

• Journal of the Korean Ceramic Society
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• v.32 no.5
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• pp.582-586
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• 1995

The crystal structures of (Na0.3Sr0.7)(Ti0.7M0.3)O3 (M=Ta, Nb) compounds were determined using the Rietveld method. Due to the tilting of a oxygen octahedron, (Na0.3Sr0.7)(Ti0.7Nb0.3)O3 had a superlattice of doubled a, b and c of simple perovskite. The crystal structure of (Na0.3Sr0.7)(Ti0.7M0.3)O3 was tetragonal with a space group 14/mmm. The crystal structure of (Na0.3Sr0.7)(Ti0.7M0.3)O3 was a cubic with space group Pm3m, in which no tilting of oxygen octahedron was observed. The difference in the oxygen tilting of these two materials was due to the larger covalency of Nb-O bond than that of Ta-O bond, which induced a strong $\pi$Nb0 bonding in (Na0.3Sr0.7)(Ti0.7M0.3)O3. Therefore, the higher transition temperature of (Na0.3Sr0.7)(Ti0.7M0.3)O3 could be related to the larger tilting of oxygen octahedron.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.834-838
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• 2000

As an endeavor to establish a micropropagation system for Epimedium koreanum Nakai., this study was carried out to define methods to disinfect its explants and media for callus induction, proliferation and plant regeneration. The lowest infection rates by fungi or bacteria on apical and axillary bud explants of rhizome were observed when they were immerged in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 30 min, but leaf explants were seldom infected with fungi or bacteria by this disinfectant method. The highest rate of plantlet formation was obtained from the explants disinfected in 0.3% NaOCl solution for 20 min after soaked in 0.1% $AgNO_3$ solution for 60 min for tip buds and in 0.1 % $AgNO_3$ solution for 30 min for axillary buds of rhizome. Induction rate of callus was the highest from the explants disinfectd in 0.3% NaOCl solution for 20 min after soaked in 0.2% $AgNO_3$ solution for 15 min. Callus growth was proper in a modified 1/2 MS medium including half strength of $NH_4NO_3$ with $0.02-0.2mg{\cdot}L^{-1}$ BA and $2.0mg{\cdot}L^{-1}$ NAA. Low rate of plantlet regeneration was obtained in 1/2 UM or 1/2 White medium with $2.0mg{\cdot}L^{-1}$ BA and $0.2mg{\cdot}L^{-1}$ AA.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.193-197
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• 1973

1. Two desert perennial plant species (Lycium andersonii Gray and Atriplex confertifolia (Torr. & Frem) Wats.) were grown in soil in a glasshouse with different sources of Na ($NO_3{^-}$, $Cl^-$, $H_2PO_4{^-}$) to evaluate their effects upon cation-anion balance in the plants. 2. Each anion greatly increased in leaf with only minor, if any, interactions with other anions 3. The miliequivalent sum of anions measured (N. P. Cl), increased in each plant part with the soil applications. 4. Simultaneously there were usually modest increases in the me. sum of cations. 5. The cation-anion ratio was decreased markedly when $NaNO_3$ was added. The ratio was usually over one. 6. Maximum content of Cl and N in leaves with L. andersonii. was 13.5%, and 6.37% respectively, when each was added. 7. Sodium concentrations were higher for the Atriplex species than for L. andersonii. 8. There were some compensations among other cations as sodium was increased, so that a somewhat constant sum of cations was maintained although there were significant differences among different sources of Na. 9. L. andersonii appeared to be an accumulator of Li.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.86-86
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• 2009

The $(Na_{0.5}K_{0.5})NbO_3-SrTiO_3$ ceramics were produced by the conventional solid-state sintering method, and their microstructure and electrical properties were investigated. All $(Na_{0.5}K_{0.5})NbO_3-SrTiO_3$ ceramic show dense and homogeneous structure without the presence of the rosette structure. The dielectric constant, loss and remanent polarization of $(Na_{0.5}K_{0.5})NbO_3-SrTiO_3$ ceramics were superior to those of single composition $(Na_{0.5}K_{0.5})NbO_3$

• Journal of the Korean Ceramic Society
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• v.30 no.2
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• pp.85-92
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• 1993

Oxynitride glasses in Na-Ca-Si-O-N system were prepared by melting at 135$0^{\circ}C$ for 2 hours in N2 gas. The effects of Si/Na mole ratio and the various Si3N4 contents were investigated. Stable oxynitride glasses can be obtained up to 9wt.% Si3N4 content in case the Si/Na mole ratio was 2.12 and 1.62, but $\beta$-Si3N4 was precipitated at 9wt.% Si3N4 content in case the Si/Na mole rtio was 1.12. Density (p), chemical durability, hardness (Hv), and fracture toughness (KIC) increased with increasing Si3N4 content. In cae the Si/Na mole ratio was 1.12, the increment of properties was remarkable but hardness and fracture toughness did not increase no longer owing to precipitation of $\beta$-Si3N4.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.275-286
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• 2014

This study evaluated the evolution stage and origin of chemical components of 12 boreholes at crystalline bedrock using multivariate statistical and groundwater quality analyses. Groundwater types are mostly belonged to Na(Ca)-$HCO_3$ and Ca-$HCO_3$ types, indicating that directly reaction of cation exchange ($Ca^{2+}{\rightarrow}Na^+$) prevailed. The degree of groundwater evolution is included the range from low to intermediate stage based on field and laboratory analytical conditions. As a result of multivariate statistical analysis, a typical indicator of groundwater contamination, $NO_3$-, has the positive correlation with $Na^+$ and $Cl^-$. The origin of sea spary ($Cl^-$) has the positive correlation with $Na^+$, $SO{_4}^{2-}$, $Mg^{2+}$, and $K^+$, while not correlation with $Ca^{2+}$, $Fe^{2+}$, $HCO_3{^-}$, $F^-$, and $SiO_2$. The concentration of $Cl^-$ and $NO_3{^-}$ belongs to general quality of groundwater and not exceeds over the Korean standard for drinking water. And the negative values of saturation index of minerals are calculated with chemical components in groundwater. Therefore, most of chemical components of groundwater in the study area are originated from natural process between rock and groundwater, whereas some of components are derived from sea spary and anthropogenic sources related to agricultural activities.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.110-117
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• 2016

In the existing research, the ammonia aqueous solution was used in order to remove the Nitrogen dioxide using the scrubber. However, ammonia is poisonous and stench is extreme. So, the system application follows the difficulty. Experiments were conducted to find a substitute material ammonia. The sodium hydroxide(NaOH), sodium thiosulfate ($Na_2S_2O_3$), and urea were used with the substitute substance. The experimental condition proceeded as the optimum conditions in the existing ammonia use. The experimental result NaOH and $Na_2S_2O_3$ was available. NaOH showed the efficiency which is the highest in 2.5%. And $Na_2S_2O_3$ showed the efficiency which is the highest in 5.0%. The efficiency was not fixed and the urea was inappropriate with the substitute substance.

• Journal of Environmental Health Sciences
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• v.20 no.2
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• pp.39-54
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• 1994

Dry and wet deposition samples were continuously collected by deposit gauge. In Bulkwang area of Seoul and Kanghwa in west coastal area of Korea. In order to evaluate the level of air pollution and its chemical composition, Bulkwang area located in Seoul and Kanghwa in west coastal area were chosen for sampling site. dry deposition concentrations, pH, electric conductivity and water soluble ion concentrations of deposit gauge were analysed. The results of comparison between urban area and coastal area were summarized as follows. Mean concentrations of dry deposition in Bulkwang was 2.807 ton/km$^2$/month (range: 5.171~1.128 ton/km$^2$/month) while that in Kanghwa was 1.990 ton/km$^2$/month (range: 3.358 ~ 1.084 ton/km$^2$/month), which showed a significant difference between two areas. The rainfall during the period from June to September in 1990 recorded 1859.7 mm which was 78.8% of its mean amount in Seoul, and 1846.9 mm which was 81.6% that of Kanghwa. In Bulkwang area, correlation coefficients of deposit chemical composition were 0.95 for SO$_4^{-2}$ and Na$^+$, 0.94 for SO$_4^{-2}$ and NH$_4^+$, 0.93 for CI$^-$ and NH$_4^+$ and 0.85 for Cl$^-$ and Ca$^{2+}$, respectively. Then, the results indicate that sulfates such as $Na_2SO_4$, $(NH_4)_2SO_4$, and CaSO$_4$ were the major chemical state of deposit. In Kanghwa area, it was considered that NaCl, $NH_4NO_3$, NaNO$_3$, and $Ca(NO_3)_2$ were the major chemical state of deposit.