• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.439-454
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• 2008

The purpose of this study was to extensively identify $PM_{10}$ sources and to estimate their contributions to the study area, based on the analysis of the $PM_{10}$ mass concentration and the associated inorganic elements, ions, and total carbon. The contribution of $PM_{10}$ sources was estimated by applying a receptor method because identifying air emission sources were effective way to control the ambient air quality. $PM_{10}$ particles were collected from May to November 2007 in the Yongin-Suwon bordering area. $PM_{10}$ samples were collected on quartz filters by a $PM_{10}$ high-volume air sampler. The inorganic elements (Al, Mn, V, Cr, Fe, Ni, Cu, Zn, Cd, Pb, Si, Ba, Ti and Ag) were analyzed by an ICP-AES after proper pre-treatments of each sample. The ionic components of these $PM_{10}$ samples ($Cl^_$, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) were analyzed by an IC. The carbon components (OC1, OC2, OC3, OC4, OP, EC1, EC2 and EC3) were also analyzed by DRI/OGC analyzer. Source apportionment of $PM_{10}$ was performed using a positive matrix factorization (PMF) model. After performing PMF modeling, a total of 8 sources were identified and their contribution were estimated. Contributions from each emission source were as follows: 13.8% from oil combustion and industrial related source, 25.4% from soil source, 22.1% from secondary sulfate, 12.3% from secondary nitrate, 17.7% from auto emission including diesel (12.1%) and gasoline (5.6%), 3.1% from waste incineration and 5.6% from Na-rich source. This study provides information on the major sources affecting air quality in the receptor site, and therefore it will help us maintain and manage the ambient air quality in the Yongin-Suwon bordering area by establishing reliable control strategies for the related sources.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.999-1006
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• 2015

The endo-polygalacturonase gene (endo-pgaA) was cloned from DNA of Aspergillus niger SC323 using the cDNA synthesized by overlapping PCR, and successfully expressed in Saccharomyces cerevisiae EBY100 through fusing the α-factor signal peptide of yeast. The fulllength cDNA consists of 1,113 bp and encodes a protein of 370 amino acids with a calculated molecular mass of 38.8 kDa. After induction by galactose for 48 h, the activity of recombinant endo-PgaA in the culture supernatant can reach up to 1,448.48 U/mg. The recombinant protein was purified to homogeneity by ammonium sulfate precipitation and gel filtration column chromatography and subsequently characterized. The optimal pH and temperature of the purified recombinant enzyme were 5.0 and 50℃, respectively. The Michaelis-Menten constant (K_m) and maximal velocity (V_max) of the enzyme for pectin were 88.54 μmol/ml and 175.44 μmol/mg/min, respectively. The enzyme activity was enhanced by Ca²⁺, Cu²⁺, and Na⁺, and strongly inhibited by Pb²⁺ and Mn²⁺. The pectin hydrolysates were mainly galacturonic acid and other oligo-galacturonates. Therefore, these characteristics suggest that the recombinant endo-PgaA may be of potential use in the food and feed industries.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.62-67
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• 1994

Introduction : Recently, water and environmental pollution becomes serious social problem and high technology makes this pollution accelerate. Hydrogen sulfide, the main subject of our research, is one of the most dangerous air pollutant like SO$_x$ and NO$_x$. The major contaminant in coal gasification is H$_2$S, which is very toxic, hazardous and extremely corrosive. Therefore, control of hydrogen sulfide to a safe level is essential. Although commercial desulfurization process called liquid scrubbing is effective for removal of H$_2$S, it has drawbacks, the loss of sensible heat of the gas and costly wastewater treatment. Many investigations are carried out about high-temperature removal ol H$_2$S in hot coal-derived gas using metal oxide or mixed metal qxide sorbents. It was reported that ZnO was very effective sorbent for H2S removal, but it has big flaw to vaporize elemental zinc above 600\ulcorner \ulcorner As alternative, metal oxides such as CaO, $Fe_2O_3$, TiO$_2$ and CuO were added to ZnO. Especially, different results are reported for $Fe_2O_3$ additive. Tamhankar et al. reported SiO$_2$ with 45 wt% $Fe_2O_3$ sorbent is favorable for removal of H$_2$S and regeneration.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.33-46
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• 2018

Traditional inorganic pigments applied to dancheong, buddhist painting, and wall painting were produced from natural minerals which were later replaced by synthetic pigments, resulting in the loss of the recipe to prepare mineral pigments. This study examined the domestic occurrence and mineralogical characteristics of green and blue mineral pigments required for the conservation of cultural heritage. Cuprous green-blue mineral pigments were found as the weathering products of waste dumps and ores of abandoned Cu-Pb-Zn sulfide mines. Mineralogical analyses using X-ray diffraction and scanning electron microscopy identified diverse hydrous copper sulfate pigments of green (brochantite and devilline) and blue color (linarite, bechererite, and schulenbergite) with minor green pigments of antlerite and atacamite commonly associated with cerussite, smithsonite, anglesite, and cuprite. Noerok, a green silicate pigment, replaced the fractured basalt lava. Celadonite was responsible for the green color of Noerok, closely associated with opal in varying ratio. Glauconite, green silicate pigment, was identified in the Yellow Sea sediments. Malachite and azurite, the most important green and blue pigments of Korean cultural heritage, were not identified in this study.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.33-43
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• 2013

A bacterium producing a fibrinolytic enzyme was isolated from Cheonggukjang. The bacterium was identified as a strain of Bacillus amyloliquefaciens by 16S rDNA analysis and designated as B. amyloliquefaciens HC188. The optimum culture medium appeared to be one containing 0.5% (w/v) maltose and 0.5% (w/v) soytone. Bacterial growth in the optimal medium at $37^{\circ}C$ reached the stationary phase after 27 h of incubation and the fibrinolytic enzyme showed optimum activity at 24 h. The enzyme was purified by 20-80% ammonium sulfate precipitation, CM Sepharose fast flow ion exchange chromatography, and Sephacryl S-200HR column chromatography. Its specific activity was 38359.3 units/mg protein and the yield was 5.5% of the total activity of the crude extracts. The molecular weight was 24.7 kDa and the amino acids of the N-terminal sequence were AQSVPYGVSQIKAPA. The fibrinolytic enzyme activity had an optimum temperature of $40^{\circ}C$ and an optimum pH of 8.0, and the enzyme was stable in the ranges $20-40^{\circ}C$ and pH 6.0-8.0. Enzyme activity was increased by $Ca^{2+}$ and $Co^{2+}$ but inhibited by $Cu^{2+}$, EDTA, and PMSF. It is suggested that the purified enzyme is a metallo-serine protease.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.254-264
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• 2012

Rayleigh-Benard natural convection experiments were carried out as the preliminary experiment to simulate the natural convection of the core melt at the severe accident conditions. This work focused on the influences of plate separation distance(s), the existence of the side walls and crust geometries of upper and lower plates. Based upon the analogy concept, a cupric acid-copper sulfate electroplating system($H_2SO_4-CuSO_4$) was employed as the mass transfer system and measurements were made for $Ra_s$ ranging from $1.06{\times}10^7$ to $2.91{\times}10^{10}$. The test results measured for a single horizontal plate were in good agreement with the correlation reported by McAdams and those for two horizontal plates showed the similar trend to the existing Rayleigh-Benard heat transfer correlations developed by Dropkin and Somerscales, Globe and Dropkin. The measured heat transfer rate decreased with the increasing separation distance between the two plates and became similar to those for a single horizontal plate. Fin arrays mounted on both upper and lower plates enhanced the heat transfer rates. For all cases, the heat transfer rates measured for open side walls are higher than those for closed ones.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.434-438
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• 2005

In the previous study, we isolated a myulchikinase (MK), which has fibrinolytic activity and cytotoxicity to the tumor cell line, from myl- chi-jeot-gal. In this study, the effect of NaCl concentration, metallic ions, pH, temperature, and plasminogen on the activity of MK was analysed. The MK activity was maintained at least $80\%$ activity up to $30\%$ NaCl, which indicates that the enzyme may be halotolerant. The optimal pH and temperature were 8 and $40^{\circ}C$, respectively. The fibrinolytic activity of MK was completely inhibited with 0.5 mM $Hg^{2+}$ and inhibited to $50^{\circ}C$ with 1 mM $Cu^{2+}\;and\;Zn^{2+}$. The MK showed strong activity in plasminogen- rich fibrin plate but not in plasminogen-free fibrin plate. The result indicates that the MK may be a plasminogen activator type fibrinolytic enzyme.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.233-243
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• 1992

Ore mineralization of the Hwanghak copper deposit in the Ogsan area occurred in three stages of quartz (stage I and II) and calcite (stage III) veining along fissures in Early Cretaceous sedimentary rocks. Ore minerals are pyrite, pyrrhotite, chalcopyrite (dominant), sphalerite, hematite, galena, and Ag-, Pb-, and Bi-sulfosalts. These were deposited during the first stage at temperatures between $370^{\circ}C$ and < $200^{\circ}C$ from fluids with salinities between 0.5 and 7.6 equiv. wt. % NaCl. There is evidence of boiling and this suggests pressures of less than 180 bars during the first stage. Equilibrium thermodynamic interpretation accompanying with mineral paragenesis and fluid inclusion data indicates that copper precipitation in the hydrothermal system occurred due to cooling and changing in chemical conditions ($fs_2$, $fo_2$, pH). Gradual temperature decrease from $350^{\circ}$ to $250^{\circ}C$ of ore fluids by boiling and mixing with less-evolved meteoric waters mainly led to copper deposition through destabilization of copper chloride complexes. Sulfur isotope values of sulfide minerals decrease systematically with paragenetic time from calculated ${\delta}^{34}S_{H_2S}$ values of 8.2 to 4.7‰. These values, together with the observed change from sulfide-only to sulfide-hematite assemblages and fluid inclusion data, suggest progressively more oxidizing conditions, with a corresponding increase of the $sulfate/H_2S$ ratio of hydrothermal fluids. Measured and calculated hydrogen and oxygen isotope valutls of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1048-1054
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• 2014

The purpose of this study was carried out to investigate the cause of sulfur dioxide occurrence, general element composition, sulfur compounds, heavy metals, macro- & micro-minerals, and oxidation-reduction potential (ORP) following baking time course of RS (RS1, RS2, RS3, and RS4) and mudflat solar salts (MSS). Sulfur dioxide ($SO_2$) and sulfite ($SO{_3}^{2-}$) were not detected in MSS or RS. However, sulfate ($SO{_4}^{2-}$) content significantly decreased in RS (29,878.15~36,097.45 ppm) compared to that in MSS (35,601.65 ppm). ORP was 181.15 mV in MSS, and 58.55 mV in RS1. Moisture content was 9.34% in MSS and 0.00% in RS with increased NaCl (94.77~95.77%). Moisture and NaCl contents showed no significant difference in RS. Insoluble and sandy residues were higher in RS than in MSS, whereas Ca and K showed no significant difference. Mg and Cl contents were higher in RS than in MSS. Br level was higher in MSS (628.1 ppm) than in RS (512.72~586.62 ppm), but there was no significant difference in $NO_3$. Heavy metals (Pb, As, and Hg) were more abundant in RS than in MSS, but levels were still safe. These results suggest that MSS and RS may increase protection against from $SO_2$ and $SO{_3}^{2-}$.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1267-1274
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• 2018

Objective: The objective of the study was to investigate the effects of zinc amino acid complex (ZnAA) on growth performance, hematological and biochemical parameters in weanling pigs. Methods: In Exp. 1, a total of 216 Duroc${\times}$Landrace${\times}$Large White weanling pigs were assigned randomly to 6 dietary treatments. Each treatment had 6 replicates (pens) with 6 pigs each. The diets were corn-soybean meal based with supplementation of 0, 20, 40, 80, 120 mg Zn/kg from ZnAA or 40 mg Zn/kg from feed-grade zinc sulfate. The experiment lasted 42 days. In Exp. 2, a total of 180 weanling pigs were assigned randomly to 3 dietary treatments supplemented with 0, 80, or 800 mg Zn/kg from ZnAA. Results: In Exp. 1, pigs fed 40 to 80 mg Zn/kg from ZnAA had higher (p<0.05) average daily gain (ADG) than the unsupplemented group during d 0 to 14. During d 0 to 42, the pigs fed 20 to 120 mg Zn/kg from ZnAA had increased (p<0.05) ADG. Pigs fed 20 to 120 mg/kg Zn from ZnAA had lower feed:gain (p<0.05), increased the activity of serum Cu-Zn superoxide dismutase on d 14, and increased serum Zn levels on d 42 (p<0.05). In Exp. 2, pigs fed diets with 800 mg Zn/kg had increased average daily feed intake during d 15 to 28 (p<0.05) compared to the unsupplemented group. During d 0 to 28, the pigs fed supplemental Zn had increased ADG (p<0.05). On d 14 and d 28, pigs fed supplemental Zn had higher the serum alkaline phosphatase activities (p<0.05). No significant differences were observed in the hematological parameters and organ indices. Conclusion: Supplementation with 20 to 80 mg/kg Zn from ZnAA improved the growth performance in weaned pigs. The piglets can tolerate up to 800 mg/kg Zn from ZnAA with limited potential health effects.