• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.701-717
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• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• Journal of Mushroom
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• v.17 no.4
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• pp.191-196
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• 2019

The edible ectomycorrhizal mushroom Amanita javanica is a valuable species protected by forest law in Korea. However, basic characterization data on its use as an important forest resource has been limited. This study was performed to determine mycelia growth characteristics of the domestically isolated Amanita javanica strain NIFoS 1267 on potato dextrose agar media under diverse culture conditions. Physical factors temperature, pH, and light, as well as chemical factors salts, heavy metals, and pesticides were examined for their effects on the growth of the mushroom strain. The mycelia of A. javanica strain exhibited optimal growth when cultured in dark at 30℃ in media with a pH of 5-6. Normal levels of growth were observed in media containing up to 2% saline. At a heavy metal ion content of 50 ppm, mycelial growth was not affected by arsenic ion but was affected by cadmium and lead ions. In the tests performed with two pesticides used in Korean forests, the growth of the mushroom strain was not affected by the presence of abamectin, but was inhibited in media containing acetamiprid, emamectin benzoate, or thiacloprid. These results are expected to facilitate artificial cultivation of A. javanica as a new commercial product.

• Applied Biological Chemistry
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• v.39 no.6
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• pp.494-500
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• 1996

Uptake of hen metal ions by water dropwort (Oenanthe stolonifera DC.) and its cadmium-binding protein were studied to probe for good method to remove heavy metal contaminants from environments. The plant was cultured in the culture medium (pH 7.0) containing the various concentrations of $Cd^{2+}$, $Cr^{3+}$ or $Pb^{2+}$, for 3 and 7 days. The residual heavy metals deposited in roots linearly increased as the metal ions concentration increased up to 17 ppm for $Cd^{2+}$, 20 ppm for $Cr^{3+}$ and 50 ppm for $Pb^{2+}$. Above these concentrations, the plant growth was inhibited and the uptake rates of the metal ions decreased. The heavy metals absorbed by the plant were mostly deposited in roots. In particular, the residual concentration of lead in roots was about four times higher than those of cadmium and chromium. When cultured in the medium containing 20 ppm of each metal ion, 80% of cadmium, 90% of cromium and 96% of lead were deposited in roots out of the total residual metal ions in the plant. These values correspond to 6.1 mg of cadmium, 5.2 mg of chromium and 23.6 mg of lead per one gram of roots tissue on a dry weight basis. A cadmium-binding protein was partially purified by extraction, gel filtration and DEAE-Cellulose chromatography from water dropworts that was grown in the medium containing 20 ppm $Cd^{2+}$. The purified protein was a single band on SDS- and non-denaturing- polyacrylamide gel electrophoresis. Its molecular mass was estimated to be ca. 5,000 dalton by gel filteration. Analysis of amino acid composition of the protein indicated that it had a typical amino acid composition of heavy metal-binding protein in that it contained 27% of acidic amino acids and 9.9% of cysteine. However, it is likely that the protein is a new plant metal-binding protein, since its amino acid composition is somewhat different from those of phytochelatins that have been known so far.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.140-147
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• 2017

This paper describes the design and implementation of previously developed PMU (Power Monitoring Unit) for LiPB (Lithium-ion Polymer Battery) that is electric propulsion used as unmanned aerial vehicle's power source. Improved PMU provides stable voltage and current to various sensors and elctric motors necessary during flight. Voltage and current monitoring function that is measured by improved PMU more precisely be enhanced and the monitoring channel and temperature sensor is added. To verify the improved performance of the equipment, it is integrated to electric propulsion system of unmanned aerial vehicle. PMU is calibrated through the ground test. And PMU's performance is checked through the flight test.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.391-405
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• 2020

Leaching chracteristics of Andong-dam sediment was conducted for heavy metal and nutrients. Five mixed sediment samples were prepared and leaching was conducted under aerobic and anaerobic condition for 60 days. Cd, Cu, Pb, Cr, Zn, Hg, As, Fe, Mn, phosphorus, and nitrogen were analyzed at each sampling time. The leaching rate of phosphorus was higher in anaerobic condition comparing with that of under aerobic condition. Some samples showed higher than the water-quality level IV. In case of As and Cd which showed highest contamination level in the sediment, leached concentration were 0.028 mg/L and 0.003 mg/L in maximum, respectively. The leached concentration is below than the lake water quality standard of Korea. Other heavy metals including Cu, Pb, and Cr also showed similar trend. Five step sequential extraction showed that easily extractable 1-2 step portion such as ion-exchangeable and adsorbed one was less than 10% and the most of the portion was residual. For As and Cd, the residual portion were 80% and 95% respectively indicating the risk by the heavy metal leaching into the lake for a short period was not high in comparing with the contamination levels.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.1-3
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• 2002

The eastward extension of the suture zone between the Sino-Korea and Yangtze cratons in the Korean Peninsula and Japanese islands remains debatable (Hiroi, 1981; Cluzel et al., 1991; Yin and Nie, 1993; Sohma and Kunugiza, 1993; Isozaki, 1997; Arakawa et at., 2000), and is related to our understanding of the continent-continent collision orogeny. The collision orogeny varies in tectono-metamorphic processes and the timing differs from place to place, as exemplified by the absence of coesite and micro-diamond in the Korean Peninsula and Japanese islands, because it is a long-lived process of more than several tens of million years from subduction to exhumation in the Wilson cycle, and because the suture zone extends more than several thousand kilometers with a curved shape from the Qinling area of China to the Hida highland area of Japan. Hiroi (1981) is the first paper to correlate the Unazuki metamorphic rocks of the Hida metamorphic belt in Japan with the Ogcheon belt in the Korean Peninsula based on the presence of 240 Ma medium P/T metamorphic rocks in both belts, but there is a lack of recent studies on this correlation. To resolve the correlationship, there are two approaches: 1) petrological studies characterizing the origin and P-T history of rocks and 2) in-situ micro-dating of fine-grained, zoned minerals of zircon, monazite, uraninite and thorite using the EPMA (U-Th-Pb chemical dating or CHIME depending on calibration method) and the SHRIMP (Sensitive High-resolution ion Microprobe) to decipher the timing of geological events. As a first step of these approaches, micro-dating was undertaken to rocks of the Hida metamorphic belt and its Mesozoic cover (Tetori Group) in the Hida highland area, central Japan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.547-557
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• 1986

The characteristics of the three alkaline proteinases, Enz. A, B and C, from the pyloric caeca of mackerel have been investigated. The optimum condition for the activity of the Enz. A, B and C was pH 9.4, 9.8 and 9.8 at $45^{\circ}C$ for $2\%$ casein solution, and was pH 9.2 10.2 and 9.8 at $45^{\circ}C$ for $5\%$ hemoglobin denatured by urea, respectively. Enz. A, B and C by heat treatment at $50^{\circ}C$ for 5 min were inactivated 90, 33 and $37\%$, respectively, over the original activity. The reaction rate of the three alkaline proteinases was constant to the reaction time to 40 min in the reaction condition of $2{\mu}g/ml$ of enzyme concentration and $2\%$ casein solution. The reaction rate equation and Km value against casein substrate determined by the method of Lineweaver and Burk were: Enz. A, Y=3.6X and $Km=5.0{\times}10^{-3}\%$; Enz. B, Y=6.0X and $Km=1.0{\times}10^{-3}\%$; Enz. C, Y=4.2X and $Km=3.6{\times}10^{-3}\%$. The three alkaline proteinases were inactivated by $Ag^+$ and $Hg^{2+}$, but activated by $Mn^{2+},\;Sn^{2+}\;and\;Pb^{2+}$, Enz. B and C were remarkably inhibited by the soybean trypsin inhibitor. Molecular weight of Enz. A, B and C determined by SDS-polyacrylamide gel electrophoresis and Sephadex G-100 gel filtration was in the range of $27,500{\pm}2,500,\;20,500{\pm}1,500\;and\;15,250{\pm}250$, respectively.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1355-1367
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• 2007

This study summarizes the relations among $PM_{2.5}$ concentration, water-soluble ions concentration, metallic element Components characteristics and SPSS in negative ion and metallic element of $PM_{2.5}$ particle in Miryang.(By the urban area, the industrial complex area and the suburban area according to the season) $PM_{2.5}$ concentration of total 72 samples collected from 3 sites turned out to range from 3.47 to 34.7 ${\mu}g/m^3$, and the average concentration was the suburban area-the kin nup(16.00 ${\mu}g/m^3$) > the urban area-the roof of the old Miryang university(10.32 ${\mu}g/m^3$) > the industrial complex-Sapo industrial complex(10.29 ${\mu}g/m^3$). In particular, the suburban area had $PM_{2.5}$ concentration 1.5 times those of urban area, industrial complex. It was thought although the site was suburban and farm-side without pollutants around, it had a higher concentration value influenced by external factors including the brickyard, small-scale incinerator, driving range construction, construction on the Daegu-Busan express and the widening of the four-lane road between Miryang-Anyang nearby. As for water-soluble ions among $PM_{2.5}$ particle collected in Miryang area, $SO4_{2^-}$ accounted for 60% and $NO_{3^-}$, was 30% in spring and summer. And $NO_{3^-}$ accounted for 50% and $SO4_{2^-}$ was 35% in fall and winter. The AI value of metallic Components among $PM_{2.5}$ particle collected in Miryang area had a high value influenced by the apartment complex construction and the extension work of road. The industrial complex area had Zn concentration 3 times, and Fe concentration 2 times those of urban area and suburb area. When it comes to the relation with metallic elements in urban area, the highest coefficient of correlation was between Cr-Fe with 0.85, and Pb-Cd turned out in the reverse correlation. Among metallic elements, the coefficients of correlation between Zn and Cr, Mn, Fe, NI were high in industrial complex area. The highest coefficient of correlation was between Mn-Zn with 0.88, meanwhile Ni and Cu, Cd turned out in the reverse correlation in the suburb area. These coefficients of correlation are attributed to the difference in pollutant sources, rather than difference in pollutant and non-pollutant.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.711-722
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• 2011

This study is aimed to estimate the $PM_{2.5}$ source apportionment at Seoul intensive monitoring site located in Seoul metropolitan area. Time-resolved chemical compositions of $PM_{2.5}$ are measured in real time using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF at Seoul intensive monitoring site in 2010. The mass concentration of $PM_{2.5}$ was simultaneously monitored with eight ionic species (${SO_4}^{2-}$, $NO_3{^-}$, $Cl^-$, $NH_4{^+}$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$), two carbonaceous species (OC and EC), and fourteen elements (Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Pb) in 1-hr interval. The data sets were then analyzed using EPA PMF version 3 to identify sources and contributions to $PM_{2.5}$ mass. EPA PMF modeling identified eight PM2.5 sources, including soil dust, secondary sulfate, secondary nitrate, motor vehicle, coal combustion, oil combustion, biomass burning, and municipal incineration. This study found that the average $PM_{2.5}$ mass was apportioned to anthropogenic sources such as motor vehicle, fuel combustion, and biomass burning (61%) and secondary aerosols, including sulfate and nitrate (38%).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.8
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• pp.597-601
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• 2013

The accelerated thermal aging of a CSPE were carried out for 0, 80.82, 161.63 days at $100^{\circ}C$, which are equal to 0, 40 and 80 years of aging at $50^{\circ}C$, respectively. The volume electrical resistivities of the seawater and freshwater flooding were measured through 3-terminal circuit diagram. The volume electrical resistivities of the 0y, 40y and 80y were $2.454{\times}10^{13}{\sim}1.377{\times}10^{14}{\Omega}{\cdot}cm$, $1.121{\times}10^{13}{\sim}7.529{\times}10^{13}{\Omega}{\cdot}cm$ and $1.284{\times}10^{13}{\sim}8.974{\times}10^{13}{\Omega}{\cdot}cm$ at room temperature, respectively. The dielectric constant of the 0y, 40y and 80y were 2.922~3.431, 2.613~3.285 and 2.921~3.332 at room temperature, respectively. It is certain that the ionic ($Na^+$, $Cl^-$, $Mg^{2+}$, ${SO_4}^{2-}$, $Ca^{2+}$, $K^+$) conduction current was formed by the salinity of the seawater. The volume electrical resistivity of the cleaned CSPE via freshwater trends slightly upward with the number of dried days at room temperature. As a result, the $CH_2$ component of thermally accelerated aged CSPE decreased after seawater and freshwater flooding for 5 days respectively, whereas the atoms such as Cl, O, Pb, Al, Si, Sb, S related with the conducting ion ($Na^+$, $Cl^-$, $Mg^{2+}$, ${SO_4}^{2-}$, $Ca^{2+}$, $K^+$) component increased relatively.