• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.632-639
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• 1990

The biological activities of twelve different kinds of enzymatic browning reaction products(EBRP), which resulted from the reactants four kinds of polyphenols with polyphenol oxidase extracted from Ligularia fischeri, pimpinella brachycarpa and Aster scaber of edible mountain herbs. All of twelve samples did not show any mutagenic effect in the spore rec-assay, Ames mutagenicity test and DNA breaking test. However metal ions such as $Cu^{2+},\;Fe^{2+}$, and $Ni^{2+}$ were increased the DNA breakage in rec-assay. The EBRPs inhibited the mutagenicities induced by $benzo({\alpha})pyrene (B({\alpha})P)$, 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole(Trp-P-1) and 2-aminofluorene(2-AF) in Salmonella/microsome assay system with S-9 mix. In effects of EBRPs on the DNA repair system, the activity of EcoRI was highly inhibited and that of $T_{4}$ DNA ligase was inactivated by addition of EBRPs. The results of transformation ratio of plasmid pGA658 into E. coli HB 101 was significantly decreased by the reaction products of S. brachycarpa polyphenoloxidase (PPO). When UV light was exposed to the mixture of DNA and EBRP before the thanformation, the reaction products from L. fischeri PPO with pyrogallol, catechol and hydroxyhydroquinone stimulated transformation ratio.

• Proceedings of the Turfgrass Society of Korea Conference
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• 2011.02a
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• pp.25-32
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• 2011

본 연구는 화력발전의 부산물로 발생하는 석탄바닥재가 골프장 사질 토양의 개량재로 사용 적합한지를 평가하기 위해 수행되었으며, 결과를 요약하면 다음과 같다. 1. 석탄바닥재의 화학성을 분석한 결과 총질소 0.34%, 가용성 인산 $52mgL^{-1}$, 치환성 칼륨 $51mgL^{-1}$ 뿐만 아니라 소량의 치환성 칼슘과 마그네슘을 함유하고 있어 식물생육에 이롭고, 유해중금속함량은 Cd, $Cr^{6+}$, Pb, Ni, As는 $1mgL^{-1}$ 이하, Cu 농도는 $1.25mgL^{-1}$ 검출되어 토양환경보전법의 토양오염우려기준 이하이므로 석탄바닥재 재활용으로 인한 토양오염 가능성은 매우 낮은 것으로 판단된다. 2. 모래 토양에 석탄바닥재를 부피비로 0~50% 비율로 혼합한 시료의 투수계수와 유효수분함량을 측정한 결과 석탄바닥재 혼합비율이 증가할수록 투수계수는 유의성 있게 감소하고 유효수분함량은 유의성 있게 증가해 석탄바닥재가 모래 토양의 낮은 수분보유력을 개선하는 효과가 있음을 확인하였다. 3. 모래 토양에 석탄바닥재를 부피비로 0~50% 비율로 혼합한 시료를 잔디식재층으로 조성한 라이시미터에 잔디종자 파종 후 약 4개월 뒤 잔디밀도가 완전히 형성된 후에 시비 후 3일 간격으로 채취한 용탈수를 분석한 결과 1일과 4일 후에 채취한 초기 용탈수에서는 석탄바닥재 혼합비율이 높을수록 $NO_3-N$, $NH_4-N$ 및 K함량이 유의성 있게 감소했으며, 대조구에 비해 석탄바닥재 혼합비율이 높은 처리구일수록 $NO_3-N$, $NH_4-N$ 및 K함량이 용탈수 채취기간 동안 지속적으로 용탈되었다. 이 결과로 석탄바닥재가 모래 토양의 낮은 양분 보유력을 개선하는데 효과적이고 석탄바닥재처리가 대조구에 비해 오랫동안 식물 생육에 필요한 양분을 공급하는 효과가 있음을 확인하였다. 4. 골프장 그린상구조와 동일한 시험포장을 만들고 모래 토양에 석탄바닥재 10%와 20% 그리고 피트, 액시스, 이소라이트를 부피비로 10% 비율로 혼합한 시료를 잔디식재층으로 조성하고 크리핑 벤트그래스(Agrostis paulstris Huds), Penn A-4 $10gm^{-2}$을 파종한 후에 처리구별로 잔디 품질을 평가하기 위해 잔디 밀도, 뿌리길이, 색상 및 시각적 품질을 조사한 결과 석탄바닥재 처리구는 기존에 사용하는 개량제인 피트, 액시스, 이소라이트 처리구와 동등한 잔디생육 촉진 효과가 있는 것으로 조사되었다. 5. 결론적으로 석탄바닥재는 골프장 토양의 물리적 특성과 화학적 특성을 개선하고 잔디생육에 필요한 양분을 공급하는데 효과적인 토양개량재라고 할 수 있다.

• Clean Technology
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• v.23 no.2
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• pp.158-162
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• 2017

$FeCl_3$ solution has been used as an etchant for metal etching such as Fe, Cu, Al and Ni. In the etching process, $Fe^{3+}$ is reduced to $Fe^{2+}$ and the etching efficiency is decreased. Waste $FeCl_3$ etchant has environmental, economic problems and thus the regeneration of the etching solution has been required. In this study, HCl was mixed with the $FeCl_2$ solution and then, $H_2O_2$, $NaClO_3$ were added into the mixed solution to oxidize the $Fe^{2+}$. During the oxidation process, oxidation-reduction potential (ORP) was measured and the relationship between ORP and oxidation ratio was investigated. The ORP is increased with increasing the concentration of $H_2O_2$ and $NaClO_3$, and then the ORP is decreased with oxidation progress. Such a behavior was in good agreement with Nernst's equation. Also, the oxidation efficiency was about 99% when a sufficient amount of HCl and $H_2O_2$, $NaClO_3$ were added.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.21-28
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• 2018

The contents of total nitrogen, total phosphate, and total potash are important factors to determine the application rate of the organic fertilizers to arable lands. The concentrations of nutrient, organic matter, salt, water, heavy metal in mixed oil cakes and mixed organic fertilizers in circulation were investigated with 141 and 179, respectively. The mean levels of total nitrogen, total phosphate, and total potash in organic fertilizers of from 2015 to 2017 were 4.9%, 2.8%, 1.7%, respectively. The average contents of organic matter, salt, and water were 77.0%, 11.5%, and 0.3%, in mixed oil cakes, and 72.3%, 11.7%, 0.5% in mixed organic fertilizer, respectively. The maximum concentrations of Cr, Cu, Ni, and Zn were found to be in accordance with the official standard of commercial fertilizer. In order to promote balanced nutrient absorption of crops, it is necessary to increase the average content of total potash of the organic fertilizers to 3.2%.

• Journal of Korea Foundry Society
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• v.11 no.6
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• pp.475-481
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• 1991

In this study the fabrication technology and mechanical properties of AC8A/$Al_2O_3$ Composites by squeeze casting process were investigated to develope for application as the piston materials that require good friction, wear resistance, and thermal stability. AC8A/$Al_2O_3$ composistes without a porosity and the break of preform were fabricated at the melt temperature of $740^{\circ}C$, the preform temperature of $500^{\circ}C$, and mold temperature of $400^{\circ}C$ under the applied pressure of $1200kg/cm^2$ as the results of the observation of microstructures. As the results of this study, the tensile strength of AC8A/$Al_2O_3$ composites was not increased linearly with $Al_2O_3$ volume fraction and so it seemed not to agree with the rule of mixture, which had been used often in metal matrix composite. Also the tensile strength after thermal fatigue test was little different from that before the test. Consequently it was thought that AC8A/$Al_2O_3$ composites fabricated under our experimental conditions had a good thermal stability and subsequently a good interface bonding. Wear rate(i.e., volume loss per unit sliding distance) of AC8A/$Al_2O_3$ composites was decreased with $Al_2O_3$ volume fraction and the sliding speed at both room temperature and $250^{\circ}C$ and so there was a good correlation between wear rate and hardness. Also the wear rate of AC/8A20% $Al_2O_3$ composities was obtained the value of $1.65cm^3/cm$ at sliding speed of 1.14m/sec as compared with about $3.0\;{\times}10^{-8}cm^3/cm$ hyereutectie Al-Si alloy(Al-16%Si-2%Cu-1%Fe-1%Ni), which applied presently for piston materials. The wear behavior of $Al_2O_3$ composites was observed to a type of abrasive wear by the SEM view of wear surface.

• Korean journal of food and cookery science
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• v.14 no.1
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• pp.25-32
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• 1998

To measure the contents of several heavy metal elements (Cr, Mn, Ni, Cu, Zn, Cd, Hg, Pb) in Korean seaweeds which are closely related to food resources, various seaweed samples were collected from thirteen to seventeen seaweed-producing districts. The results obtained from the experiment are summarized as follows: 1. The content of heavy metal elements in seaweeds of individual sample ranged from 0.0005 to 25.0373 ppm. Their mean levels were as follows: laver, 0.0024∼3.9297 ppm; sea lettuce, 0.0011∼25.0373 ppm; sea mustard, 0.0005∼23.5071 ppm; sea tangle, 0.0006∼4.8550 ppm. The mean levels of Cd and Pb were specially low in the samples collected from the area II in Kangwon and area Ⅸ in Kyungbook. 2. The mean levels of heavy metal elements of collected samples ranged from 0.0117 to 4.4944 ppm. Laver showed the lowest level of Hg and sea lettuce showed the highest level of Mn. Their mean levels of elements were as follows: laver, 0.0117∼2.3339 ppm; sea lettuce,0.0232∼4.4944 ppm; sea mustard, 0.0129∼1.5139 ppm and sea tangle, 0.0182∼1.7410 ppm. 3. The mean levels of heavy metal elements from several locations ranged from 0.0085 ppm to 8.4148 ppm. The mean levels of heavy metal elements in sea mustard from area V of Kyungbook were the lowest, but the mean levels of heavy metal elements in sea lettuce from area Ⅷ of Kyungnam were the highest. The mean level of heavy metal elements were as follows: laver, 0.3613∼1.1124 ppm; sea lettuce, 0.1415∼8.4148 ppm; sea mustard, 0.0729-3.1182 ppm; sea tangle, 0.0085∼0.7587 ppm. 4. Generally the heavy metal elements were detected in the seaweed samples from all locations. The mean levels of heavy metal elements varied with locations and kinds of samples. The levels of heavy metals of the samples taken from all locations from the East Sea, the South Sea, and the West Sea areas showed 99% safety range.

• Resources Recycling
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• v.26 no.6
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• pp.84-90
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• 2017

The electro-refining process was performed to recovery high purity copper from low grade copper containing sludge in sulfuric acid. The surface morphologies and roughness of electro-refining copper were analyzed with variation of the type and concentration of organic additives, the best surface morphology was obtained 5 ppm of the gelatin type and 5 to 10 ppm of the thiol type organic additive. The crude metal consisted of copper with 86.635, 94.969 and 99.917 wt.%, several impurity metals of iron, nickel, cobalt and tin by pyro-metallurgical process. After electro-refining process, the purity of copper increases to 3N or 4N grade. The impurity concentrations and copper purities of copper crude metals, electrolyte and electro-refining copper were analyzed using ICP-OES, the electro-refining time and purity of copper crude metal to recover 4N grade copper were deduced.

• Journal of Mushroom
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• v.3 no.4
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• pp.145-153
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• 2005

Two hundred seventy-four microorganisms were isolated from the soil of abandoned mines around for selecting the heavy metal-degrading strains and their microbial diversity was analyzed. The specimens of macrofungi were isolated from the soil of abandoned mines around for selecting the heavy metal-degrading strains. Eunseong and Dogok in Gyeongsangbuk-do, for selecting the heavy metal-degrading strains. Soil was also collected from same location. Contents of heavy metals (Cd, Cu, Pb, Zn, Ni, Cr, and As) were determined spectrometically in fruiting bodies of forty eight wild macrofungi specimens with soils. When the analysed their transfer factor from soil to fruiting body, Amanita volvata have the highest transfer factor of cadmium and arsenic. And Mycena pura showed the highest in mercury, Marasmius pulcherripes in zinc, Laccaria laccata in nickel, and Collybia confluens in chrome. When compare the population of mushrooms between the contaminated mines and Mt. Chiak as the healthy area, Genus Russula and Collybia were collected both area, but Leucocoprinus, Coprinus, Suillus, Lepiost, Gyroporus, Lepista, Microstoma, Stropharia, and Agrocybe were only in the contaminated mine area.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.133-148
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• 1987

Gibberellin(GA) 3-$\beta$ hydroxylation is very important for the shoot elogation in the higher plants, since only 3$\beta$-hydryoxylated GAs promote shoot elogation in several plants. Fluctuation of 3$\beta$-hydryoxylase activity was examined during seed maturation using two cultivars of , P. vulgaris, Kentucky Wonder (normal) and Masterpiece (dwarf). Very immature seeds of both cultivars contain high level of 3$\beta$-hydroxylase activity (per mg protein). Both cultivars showed maximum of enzyme activity (per seed) in the middle of their maturation process. Gibberellin 3$\beta$-hydroxylase catalyzing the hydroxylation of GA20 to GA1 was purified 313-fold from very early immature seeds of P. vulgaris. Crude soluble enzyme extracts were purified by 15% methanol precipitation, hydrophobic interaction chromatogrphy, DEAE ion exchange column chromatography and gel filtration HPLC. The 3$\beta$-hydroxylase activity was unstable and lost much of its activity duting the purification. The molecular weight of purified enzyme was extimated to be 42, 000 by gel filtration HPLC and SDS-PAGE. The enzyme exhibited maximum activity at pH 7.7. The Km values for [2.3-3H] GA20 and [2.3-3H]GA9 were 0.29 $\mu$M and 0.33 $\mu$M, respectively. The enzyme requires 2-oxoglutarate as a cosubstrate; the Km value for 2-oxoglutarate was 250 $\mu$M using 3H GA20 as a substrate. Fe2+ and ascorbate significantly activated the enzyme at all purification steps, while catalase and BSA activated the purified enzyme only. The enzyme was inhibited by divalent cations Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+. Effects of several GAs and GA anaogues on the putrified 3$\beta$-hydroxylase were examined using [3H]GA9 and GA20 as a substrates. Among them, GA5, GA9, GA15, GA20 and GA44 inhibited the enzyme activity. [13C, 3H] GA20 was converted by the partially purified enzyme preparation to [13C, 3H]GA1, GA5 and GA6, which were identified by GC-MS, GA9 was converted only GA4, GA15 and GA44 were converted to GA37 and GA38, respectively. GA5 was epoxidized to GA6 by the preparation. This suggests that 3$\beta$-hydroxylation of GA20 and epoxidation of GA5 are catalyzed by the same enzyme in P, vulgaris.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.65-72
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• 2013

This study was carried out to understand the long-term effects of organic waste treatments on the fate of heavy metals in soils originated from the organic wastes and consequent uptake of heavy metals by plant, together with examination of changes in soil properties and plant growth performance. In this study, the soils treated with three different organic wastes (municipal sewage sludge, alcohol fermentation processing sludge, pig manure compost) at three different rates (12.5, 25.0, 50.0 ton $ha^{-1}yr^{-1}$) for 7 years (1994 - 2000) were used. To see the long-term effect, plant growth study and soil examination were conducted twice in 2000 and 2010, respectively. There was no additional treatments of organic wastes for 10 years after the organic waste treatment for 7 years. Compared to plant growth examination conducted in 2000 using radish (Raphanus sativus cv. sodamaltari), it appeared that height, root length and diameter, fresh weight of radish grown in 2010 decreased in the plots treated with municipal sewage sludge and alcohol fermentation processing sludge and that the extent of decrease was higher with increase of sludge application rates. On the other hand, pig compost treatment increased plant height, root length and diameter, fresh weight with increasing application rates. Cu and Pb concentrations in radish root and leaves increased in 2010 compared to those in 2000 while Ni concentrations in root and leaves decreased. Zn concentration was increased only in the soils treated with pig manure compost. Multiple regression analysis among heavy metal species fractions in soils, soil pH, and metal concentrations in radish root and leaves indicated that the metal uptake by radish was governed mainly by the soil pH and subsequent increase of available heavy metal fractions in soils with organic waste treatments.