• 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 $SO_4$.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.117-127
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• 1982

Mulberry plants (Morus alba L.) were grown in pots with the following different nitrogen sources: ammonium sulphate, urea, ammonium nitrate, sodium nitrate + ammonium nitrate ($NO_3:NH_4$=2:1), and sodium nitrate. The effects of the nitrogen sources on mulberry yields, nitrogen recovery, distribution of ions and cation-anion balance (C-A) along leaf sequence and growth stage were investigated. The results were as follows: 1. Leaf yields and nitrogen recovery decreased with increasing $NO_3$-N application rates. 2. Relative cation contents in leaves in the early growth stages showed the following pattern : Na < Mg < Ca < K. However, the order of Ca and K reversed in the later stages. The order of anion contents chifted from $SO_4$ < $NO_3$ < Cl < $H_2PO_4$ in the early stages to $NO_3$ < Cl < $SO_4$ < $H_2PO_4$ in the later stages. 3. Contents of K, $H_2PO_4$, $SO_4$, $NO_3$, T-N and the sum of anion contents (${\sum}A$) were higher in upper leaves whereas Ca, Mg, Cl, the sum of cation contents (${\sum}C$) and (C-A) were higher in lower leaves. 4. When $NO_3$ in leaves decreased, Cl and K as counter-cations increased and consequently Ca decreased. 5. The (C-A) in leaves varied with leaf sequence and growth stage from 700 to 900 me/kg D.M.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.261-272
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• 2005

The groundwaters in the basin of Seomjin River are classified mainly into Na-Cl type with high EC and $NaHCO_3$ type with low EC, and are characterized by enriched $K^+,\;Mg^{2+},\; NO_3^-,\; and\;SO_4\;^{2-}$ contents. The epm fraction of $Na^+Cl^-$ in TDS increases in general with increasing EC of groundwater. The correlation patterns among dissolved ions indicate that $Na^+\;and\;Cl^-$ are derived mainly from intruded seawater, and $K^+,\;Mg^{2-},\;and\;SO_4\;^{2-}$ from anthropogenic source such as a chemical fertilizer. The groundwaters that exceed the recommended limits far agricultural irrigation water contains $23\%\;of\;Cl^-$ reflecting sea-water intrusion, but $50\%\;of\;NO_3^-$ as an anthropogenic pollution, among the wells investigated. In risk assessment of groundwaters by the EC-SAR relationship, only $40\%$ of the groundwaters shows the suitable quality for agricultural irrigation water without any sodium and salinity hazards. Consequently, the pollution sources that cause degradation of groundwater quality in the basin of Seomjin River are the usage of chemical fertilizers and the intrusion of seawater, resulted primarily from the extension of riverward backflow of seawater and secondarily from the overpumping of groundwater.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.2
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• pp.1-11
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• 1989

Sandy dust phenomena was observed from April 19 to 23, 1988 in Seoul. During this period it rained and the precipitation was collected to investigate the rain chemistry. This study was carried out to analyzed the chemical composition of precipitation by the measurements of conditivity, cations $(H^+, NH_4^+, K^+, Na^+, Ca^{2+}, MG^{2+})$, and anions $(SO_4^{2-}, NO_3^-, Cl^-, F^-, Br^-)$ which are believed to be the major ions playing an important role in the acidity of rain water. During the period of sandy dust phenomena the range of pH value and conductivity concentration of rainwater were 6.0-6.7, 172-254 $\mu \mho/cm$. The anions and cations concentrations increased and the orders of these concentrations were $SO_4^{2-} > Cl^- > NO_3^- > Na^+ > Ca^{2+} > NH_4^+ > Mg^{2+}$. THe principal chemical compounds of rainwater were estimated at $(NH_4)_2 SO_4, CaSO_4, NaCl, and MgCl_2$.

• Journal of Biomedical Engineering Research
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• v.39 no.4
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• pp.161-167
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• 2018

Polyvinyl alcohol/sodium carboxymethyl cellulose (PVA/NaCMC) hydrogels were prepared by physical crosslinking (cyclic freezing/thawing) and gamma (${\gamma}$)-ray irradiation to evaluate the effect of NaCMC concentration (2~8 wt%) on the mechanical properties and the biocompatibility of the PVA/NaCMC hydrogels. The swelling rate of PVA/NaCMC hydrogels regardless of irradiation rose with increasing NaCMC content from 2 wt% to 8 wt%, while the gelation rate was the reverse. As the NaCMC content increased from 2 wt% to 6 wt%, the compressive strength of the hydrogels increased dramatically from $8.5{\pm}2.0kPa$ to $52.7{\pm}2.5kPa$ before irradiation and from $13.5{\pm}2.9kPa$ to $65.5{\pm}8.7kPa$ after irradiation. When 8 wt% NaCMC was added afterwards, the compressive strength decreased however. The irradiated PVA/NaCMC hydrogels containing 6 wt% NaCMC exhibited the tailored properties of the swelling rate of $118{\pm}3.7%$, the gelation rate of $71.4{\pm}1.3%$, the strength of $65.5{\pm}8.7kPa$, respectively, and no cytotoxicity was observed.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.197-203
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• 2015

Particulate matter (PM) has emitted in many regions of the world and is causing many health-related problems. Thus reasonable politics and solutions are needed to reduce PM in Seoul. Further it is required to clearly explain the major portions of chemical components contained in $PM_{10}$ to figure out the characteristics of $PM_{10}$, and to develop effective reduction measures in order to decrease the adverse effects of $PM_{10}$. $PM_{10}$ samples were collected in Seoul and analyzed their ions to examine the physical and chemical characteristics of ionic species. Since hydrogen ion ($H^+$) and carbonate ion (${CO_3}^{2-}$)) cannot be analyzed by Ion chromatography (IC), concentrations of $H^+$ and ${CO_3}^{2-}$ were initially estimated by pH and equivalent differences between anions and cations in this study. Starting from the study findings, good combination results for compositional patterns between anions and cations were obtained by applying a mathematical modelling technique that was based on the mass balance principle. The ions in $PM_{10}$ were combined with $H^+$, ${CO_3}^{2-}$, and supplement for $NO_3{^-}$, $Cl^-$ formed such compounds $NH_4Cl$, $NH_4NO_3$, $CaSO_4$, $(NH_4)_2SO_4$, $NaNO_3$, NaCl, $Na_2CO_3$, and $(NH_4)_2CO_3$ in the study area.

• Analytical Science and Technology
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• v.14 no.2
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• pp.103-108
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• 2001

Rare earth elements(REE) were separated by solvent extraction with tri-n-butyl phosphate(TBP) and $NaNO_3$, followed by back extraction with water. The method was applied to the determination of REE to circumvent the spectral interferences of ICP-AES analysis. The effects of the $NaNO_3$ concentration and the addition of hydrophobic solvents on the extraction efficiencies were investigated. Increases of the $NaNO_3$ concentration enhanced the extraction efficiencies of REE, and more than 95% recoveries were obtained at 5M of $NaNO_3$ concentration. On the other hand, addition of hydrophobic solvents lowered the extraction efficiencies. The method was applied to determine the REE in the monazite sample. But the precisions of the analytical results were more than 20%.

• 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 Korean Society for Atmospheric Environment
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• v.14 no.4
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• pp.361-368
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• 1998

Acid rainwater samples were collected during 4 years from 1992 in Pusan area nearby seaside. Ionic composition of early and succeeding rainwater were investigated to identify emission sources. pH and Electronic Conductivity of samples were measured immediately after sampling. Major ion concentrations of rain samples were Na+, Ca2+, Mg2+, K+, NH4+, SO42-, NO3-, Cl- which were analyzed by ion Chromatography. 55% of early rainwater and 90% of succeeding rainwater were identified below pH 5.6. Because, Na+, K+, Ca2+ were washed mostly in early rainwater, as a result, pH values were increased by increasing rainfall amounts. It was studied that pH value was varied from ambient ion component, rainfall, and rain intensity. From the principal component analysis result, the dominant components of acid rainwater were Na+, K2+, Mg2+, Ca2+, the elements were contributed soil and marine source, the second components nuts -SO42-, SO4a-, NO3-, nuts -Ca2+ originated from man - made source.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.946-956
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• 2020

To identify the effect of sodium-alternative curing salts on the quality properties of salami through the ripening process, four salami treatments were prepared with different curing salts, T1 (-control, NaCl 1.9%), T2 (+control, NaCl 1.9%+NaNO₂ 0.01%), T3 (KCl 1.9%+NaNO₂ 0.01%), and T4 (MgCl₂ 1.9%+NaNO₂ 0.01%), under 40 days ripening conditions. Sodium-alternative salts (T3 or T4) showed characteristically different quality traits compared with T2. Especially, T3 had lower pH, water activity, volatile basic nitrogen, and lipid oxidation after 20 days of ripening period, compare with T2 or T4 (p<0.05). Sodium nitrite had critical impact on increased a* values, and T3 showed higher a* values compared with T2 or T4 (p<0.05). Sodium nitrite reduced initial growth of coliforms but sodium-alternative salts did not affect microbial growth patterns. T2-T4 containing sodium nitrite had higher content of umami nucleotide flavor compounds compared with T1, regardless of the chlorine salt species. The combined use of sodium-alternative curing salts and minimal sodium nitrite was found to be an applicable strategy on development of low sodium salami without a trade-off of the product quality.