• Journal of Environmental Science International
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• v.27 no.7
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• pp.597-610
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• 2018

This study observed particulate matter ($PM_{2.5}$ and $PM_{10}$) in the downtown area of Jeju City, South Korea, to understand the chemical composition of particulates based on an analysis of the water-soluble ionic species contained in the particles. The mass fraction of the ionic species in the sampled $PM_{10}$ and $PM_{2.5}$ was 44.3% and 42.2%, respectively. In contrast, in Daegu City and Suwon City, the mass fraction of the ionic species in $PM_{2.5}$ was higher than that in $PM_{10}$. The chloride depletion percentage of $PM_{10}$ and $PM_{2.5}$ in Jeju City was higher than 61% and 66%, respectively. The contribution of sea-salt to the mass of $PM_{10}$ (5.9%) and $PM_{2.5}$ (2.6%) in Jeju City was similar to that in several coastal regions of South Korea. The mass ratio of $Cl^-$ to $Na^+$ in the downtown area of Jeju City was comparable to that in some coastal regions, such as the Gosan Area of Jeju Island, Deokjeok Island, and Taean City. The mass fraction of sea-salt in $PM_{10}$ and $PM_{2.5}$ was very low, and the concentration of sodium and chloride ions in $PM_{10}$ was not correlated with those in $PM_{2.5}$ ($R^2$ < 0.2), suggesting that the effects of sea-salt on the formation of particulate matter in Jeju City might be insignificant. The relationship between $NH_4{^+}$ and several anions such as $SO_4{^{2-}}$, $NO_3{^-}$, and $Cl^-$, as well as the relationship between the measurement and calculation of ammonium ion concentration, suggested that sea-salts may not react with $H_2SO_4$, and $(NH_4)_2SO_4$ may be a major secondary inorganic aerosol component of $PM_{2.5}$ and $PM_{10}$ in Jeju City.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.29-34
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• 1970

This experiment was conducted to investigate the influence of amounts of lime dressed on the growth of rice by the treatment of percolation and nonpercolation in the acid sulphate soil. And also analysis of soil chemical components after treatment was carried out. The results obtained were summarized as follows: 1. In the initial stage of growth, number of tillers and plant length showed no distinct differences between the treatments of percolation and nonpercolation, but after August the effect of lime appeared and the percolation treatment was more effective than the nonpercolation. 2. Lime dressing affected good influence on the panicles, grain per panicles and the rate of grain formation, and the treatment of percolation showed better results than nonpercolation. 3. If the yield of rough rice in the control (nonpercolation and lime dressing) was 100, it was 194 in the treatment of nonpercolation 12me/100gr of lime dressed, 268 in the treatment of percolation-4me/100gr of lime and 315 in the 8me/100gr-percolation. 4. Lime dressing affected good influence on the control of Helminthosporium leaf spots. 5. In the case of lime dressing, amounts of available phosphate and soluble silicon dioxide were increased, but ferrous ion ($Fe^{{+}{+}}$) were decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.400-406
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• 1998

To investigate the effect of simulated acid rain on the change in soil chemical properties, simulated acid rain of different pH was applied to the three soils of different texture. Simulated acid rain of pH 4.0 and 6.0 did not greatly change the soil pH, while simulated acid rain of pH 2.0 decreased greatly the soil pH. Decrease in soil pH were in the order of sandy loam > loam > clay loam, while increase in exchangeable acidity was in the order of clay loam > loam > sandy loam. Amount of nutrients leached downward due to the penetration of simulated acid rain into the soil was in the order of Ca > K > Mg. Exchangeable Al was not detected when soil acidity dropped to pH 5 and exchangeable acidity increased within a range of CEC. A total 1200mm of simulated acid rain(pH 3.0) can load $12kg\;ha^{-1}$ of $H^+$ ion, $128kg\;ha^{-1}$ of sulfur, $56kg\;ha^{-1}$ of nitrogen. The acidity of simulated acid rain pH 3.0 can be neutralized by addition of $444kg\;ha^{-1}$ of slaked lime. The amount of leached bases were equivalent to 923, 1731 and $1608kg{\cdot}ha^{-1}$ in sandy loam, loam and clay loam soil respectively.

• The Korean Journal of Mycology
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• v.23 no.4 s.75
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• pp.332-339
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• 1995

Water-soluble polysaccharide (FCW) was extracted from the fruiting body of Fomitella fraxinea with neutral sodium chloride solution. The polysaccharide was further fractionated into FCW-I and FCW-II by ion exchange chromatography. The FCW-I and FCW-II were then purified by gel permeation chromatography and named as FCW-Ia and FCW-IIa, respectively. FCW-IIa showed relatively strong immuno-stimulating activity but FCW-Ia did not. By analyses of HPLC and GPC, FCW-Ia and FCW-IIa were identified to be homogeneous and their molecular weights were estimated to be about 15,000 and 8,700, respectively. FCW-Ia consisted of fucose, galactose, and mannose as main sugars and their molar ratio was 19.5 : 63.2 : 25.0. Protein was not detected in FCW-Ia. However, FCW-IIa was composed of glucose, galactose, and mannose at a molar ratio of 1.0 : 0.3 : 0.4 and contained 0.4% protein with a higher amount of glutamic acid. A small amount of uronic acid was detected in both FCW-Ia and FCW-IIa.

• Journal of Life Science
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• v.29 no.11
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• pp.1294-1303
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• 2019

Perchlorate is an anionic pollutant that is very soluble and stable in water. It has been detected not only in soil/ground water but also in surface water, drinking water, food, fish, and crops. Perchlorate inhibits iodine uptake by the thyroid gland and reduces production of thyroid hormones that are primarily responsible for regulation of metabolism. Although various technologies have been developed to remove perchlorate from the environment, biodegradation is the method of choice since it is economical and environmentally friendly. However there is limited information on perchlorate biodegradation in salt environment such as salt water. Therefore this paper reviews biodegradation of perchlorate in salt water and related microorganisms. Most biodegradation research has employed heterotrophic perchlorate removal using organic compounds such as acetate as electron donors. Biodegradation research has focused on perchlorate removal from spent brine generated by ion exchange technology that is primarily employed to clean up perchlorate-contaminated ground water. Continuous removal of perchlorate at up to 10% NaCl was shown when bioreactors were inoculated with enriched salt-tolerant perchlorate-reducing bacteria. However the reactors did not show long-term stable removal of perchlorate. Microorganisms belonging to ${\beta}$- and ${\gamma}$-Proteobacteria were dominant in bioreactors used to remove perchlorate from salt water. This review will help our understanding of perchlorate removal from salt water to develop a decent biotechnology for the process.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.665-676
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• 2003

To investigate the chemical characteristics of PM$\_$2.5/ in Seoul, Korea, atmospheric particulate matters were collected using a PM$\_$10/ dichotomous sampler including PM$\_$10/ and PM$\_$2.5/ inlet during the period of October 2000 to September 2001. The Inductively Coupled Plasma-Mass Spectromety (ICP-MS), ion Chromatography (IC) methods were used to determine the concentration of both metal and ionic species. A statistical analysis was performed for the heavy metals data set using a principal component analysis (PCA) to derived important factors inherent in the interactions among the variables. The mean concentrations of ambient PM$\_$2.5/ and PM/sub10/ were 24.47 and 45.27 $\mu\textrm{g}$/㎥, respectively. PM$\_$2.5/ masses also showed temporal variations both yearly and seasonally. The ratios of PM$\_$2.5/PM$\_$10/ was 0.54, which similar to the value of 0.60 in North America. Soil-related chemical components (such as Al, Ca, Fe, Si, and Mn) were abundant in PM$\_$10/, while anthropogenic components (such as As, Cd, Cr, V, Zn and Pb) were abundant in PM2s. Total water soluble ions constituted 30∼50 % of PM$\_$2.5/ mass, and sulfate, nitrate and ammonium were main components in water soluble ions. Reactive farms of NH$_4$$\^$+/were considered as NH$_4$NO$_3$ and (NH$_4$)$_2$SO$_4$ during the sampling periods. In the results of PCA for PM$\_$2.5/, we identified three principal components. Major contribution to PM$\_$2.5/ seemed to be soil, oil combustion, unidentified source. Further study, the detailed interpretation of these data will need efforts in order to identify emission sources.

• Food Science and Preservation
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• v.21 no.2
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• pp.193-198
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• 2014

The quality and antioxidative characteristics of drinks prepared with different mixing ratios of black garlic and Oenanthe javanica DC., BD-1 (black garlic only), BD-2 (black garlic:Oenanthe javanica DC.=2:1), BD-3 (black garlic:Oenanthe javanica DC.=1:1), and BD-4 (black garlic:Oenanthe javanica DC.=1:2), were studied. The pH increased with the increasing concentration of Oenanthe javanica DC. extract in all the tested drinks, but the sugar contents decreased. The total polyphenol contents of the drinks were 28.48 ${\mu}g/mL$ (BD-1), 41.91 ${\mu}g/mL$ (BD-2), 42.36 ${\mu}g/mL$ (BD-3), and 46.96 ${\mu}g/mL$ (BD-4). The SOD-like activity was highest for BD-4 (18.60%), followed by BD-3 (15.53%), BD-2 (12.53%), and BD-1 (10.27%). The thiobarbituric acid reactive substances (TBARS) was highest for BD-4 (52.51%), followed by BD-3 (45.70%), BD-2 (39.44%), and BD-1 (28.72%). The ferrous ion chelating activity increased with the increasing concentration of Oenanthe javanica DC extract, and BD-4 showed the best activities among all the tested drinks. The water-soluble vitamin content (vitamins B1, B2, B6, and C) of BD-4 (1197.77 ${\mu}g/mL$) was higher than those of the other drinks (BD-1, 213.02 ${\mu}g/mL$; BD-2, 477.87 ${\mu}g/mL$; BD-3, 914.72 ${\mu}g/mL$), and the vitamin C (806.21 ${\mu}g/mL$) content of the water-soluble vitamins at BD-4 was higher than those of vitamins B1 (68.04 ${\mu}g/mL$), B2 (312.51 ${\mu}g/mL$), and B6 (11.01 ${\mu}g/mL$). BD-4 showed the best score in the sensory evaluations, such as in the evaluation of the color, flavor, taste, and overall acceptability.

• Korean Journal of Remote Sensing
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• v.36 no.6_3
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• pp.1669-1679
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• 2020

This study examines the washing effect of precipitation on particulate matter (PM) and the rainwater quality (pH, electrical conductivity (EC), water-soluble ions concentration). Of six rain events in total, rainwater samples were continuously collected every 50 mL from the beginning of the precipitation using rainwater collecting devices at Pukyong National University, Busan, South Korea, from March 2020 to July 2020. The collected rainwater samples were analyzed for pH, EC, and water-soluble ions (cations: Na+, Mg2+, K+, Ca2+, NH4+, and anions: Cl-, NO3-, SO42-). The concentrations of particulate matter were continuously measured during precipitation events with a custom-built PM sensor node. For initial rainwater samples, the average pH and EC were approximately 4.3 and 81.9 μS/cm, and the major ionic components consisted of NO3- (5.4 mg/L), Ca2+ (4.2 mg/L), Cl- (4.1 mg/L). In all rainfall events, rainwater pH gradually increased with rainfall duration, whereas EC gradually decreased due to the washing effect. When the rainfall intensities were relatively weak (<5 mm/h), PM10 reduction efficiencies were less than 40%. When the rainfall intensities were enhanced to more than 7.5 mm/h, the reduction efficiencies reached more than 60%. For heavy rainfall events, the acidity and EC, as well as ions concentrations of initial rainwater samples, were higher than those in later samples. This appears to be related to the washing effect of precipitation on PM10 in the atmosphere.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.43-54
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• 1995

This study was conducted to examine the metal release of TiN-plated stainless steel orthodontic appliances by constructing the simulated orthodontic appliances equivalent to maxillary half arch, by dividing into TiN-plated and TiN-nonplated Bloops and by dividing again these groups into welded and nonwelded groups. And then, the total quantity of metal release was obtained by measuring the amounts of both soluble and precipitated nickel and chromium after immersing in artificial saliva for 15 days. And then, the corrosion appearance of surface structure was observed by using SEM. The results of this study were summarized as follows. 1. The total amounts of released nickel and chromium showed that the TiN-plated group after welding(Group 1) was 25.46 ${\mu}g$, respectively, and 17.4 ${\mu}g$, while the TiN-nonplated group after welding(Group III) was 54.69 ${\mu}g$, respectively, and 85.27 ${\mu}g$. Then, the TiN-Plated group indicated less amounts of metal release(p<0.05). 2. The total amounts of the TiN-plated group without welding(Group II) was 0.05${\mu}g$ and 0.34${\mu}g$, respectively. Then, it was shown that the TiN-plated group without welding(Group II) indicated less metal release than that of the TiN-Plated group after welding(Group I)(p<0.01, p<0.05). 3. When observing their surface structure, there were a lot of precipitate and pitting corrosion in the groups with welding(Group I & III), when the TiN-plated group(Group I) showed lower level than the TiN-nonplated group(Group IIII). On the other hand, the groups without welding(Group II & IV) indicated a little of pitting corrosion. 4. In case of observation with the naked eyes, it was shown that there were significant disco1oration and corrosion in the groups with welding(Group I & III), while there was no any remarkable change in the groups without welding(Group II & IV).

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.153-170
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• 1977

Considering the ways for the possible improvement of soil test for upland crops, various methods for the evaluation of K supplying power and testing of available soil K were reviewed in terms of theoretical principles and practical usefulness of the each method. The review was also made on the characteristics of upland crops in K requirement and on the chemical properties of major korean upland and lowland rice soils in terms of K availability. Following is the few remarks drawn from the review. 1. Quite large number of methods have been known for the evaluation of K supplying power and testing for available soil K. In nature, they can be divided into two categories; capacity-based methods and intensity-based methcds. The capacity-based methods usually measure the exchangeable and some portion of nonexchangeable K, while the intensity-based methods suggest to consider the ractivity ratios of major cations in soil solution and the energy requirement for the replacement of exchangeable soil K into soil solution. 2. As methodology for extraction of interested part of soil K, chemical extraction, electrodialysis and ion exchange methods have been known. Among these, chemical extract ion is favorable because of its simplicity. However, recently suggested Electro-Ultra-Filtration method seems to merit further study for wider use for not only K but also other nutrient availability of soils. 3. The intensity-based methods, although they are more theoretical, because of their complexity, in methods may not be adapted for practical soil tests. 4. The exchangeable K which is rather simple to measure and which well reflects the status of K reserve as nonexchangeable and is immediate pool of water soluble K may be good, if not best, criterion of soil K availability to plant in common soil testing. 5. Because there are evidences that the abundance of available K alone may not be good inclication for availability of K to plant, it is recommendable to interprete the exchangeable K data as percent saturation of exchangeable K to total C. E. C. of soil for the recommend ation of K fertilizer based on soil tests. 6. Some pot and field trial results showed the trends that percent potassium saturation to total C. E. C. better serve as the parameter for K fertilizer recommendation.