• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.97-104
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• 2016

In the preparation of Ag-coated Cu flakes using L-ascorbic acid as a reductant for the electroless Ag plating, the effects of pretreatment methods and the reductant concentration on the uniformity of Ag coating layer and the anti-oxidation property of Ag-coated Cu flakes during the heating in air were evaluated. It was found that the removal degree of surface oxide layer during the pretreatment has great influence on the uniformity of Ag coating layer and the formation degree of hole defects in the flakes has slight effect on the anti-oxidation property of Ag-coated Cu flakes. It was also verified that the reductant concentration has great influence on the coverage uniformity and thickness of Ag coating, thus it was could be considered a main process parameter. When the reductant concentration was 0.04 M, high-quality Ag-coated Cu flakes was obtained. When the concentration increased to 0.06 M, however, the anti-oxidation property of Ag-coated Cu flakes became remarkably worse owing to remnant of Cu surface non-coated with Ag by the formation of pure Ag fine particles.

• Journal of Life Science
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• v.14 no.3
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• pp.478-483
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• 2004

In a model reaction using lysyl oxidase purified partilally from bovine aorta, effect of L-ascorbic acid AsA on the oxidative reaction of lysine in collagen was investigated. Addition of Ash to the reaction mixture under aerobic conditions resulted in the decrease of enzymatic activity. In order to examine the specificity of AsA in the oxidative reaction of lysine, other reductants including A derivatives instead of AsA were added to the reaction mixture. Thiol such as glutathione had no effect on the activities of lysyl oxidase. on the other hand, it was observed that erythorbic acid, which was a stereoisomer of AsA, had the same inhibitory effect on this oxidative reaction as AsA. Moreover, by the addition of 3,4-dihydroxybenzoate, which was structural analog of AsA, the activities decreased in a similar manner to that of AsA. These results indicate that the regulatory effect of AsA on lysyl oxidase is attributed to characteristics of the structure. From the determination of Ash remained in the reaction mixture, it is shown that AsA concentration remarkably decreased by lysyl oxidase of the reaction mixture. It is hypothesized that endiol groups reduces the enzyme-bound $Cu^{+2}$ required for further progress of the reaction, and suggests that AsA regulates specifically the reduction of $Cu^{+2}$ required to oxidize lysyl oxidase. This findings support that AsA has an important regulatory role on the oxidative reaction of lysine and on changes of collagen cross-links with aging.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.1-8
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• 2010

Natural convection heat transfer rates in a vertical pipe were measured for $Gr_H$ number from 2.1x$10^6$ to 1.2x$10^9$. Using the analogy concept, heat transfer experiments were replaced by mass transfer experiments. A cupric acid - copper sulfate ($H_2SO_4-CuSO_4$) electroplating system was adopted as the mass transfer system and the mass transfer rates were measured. Comparison of the results with the existing laminar and turbulent natural convection heat transfer correlations on a vertical plate showed very good agreements except for the high $Gr_H$ case, where the boundary layer inside the vertical pipe interferes. The agreements showed the usefulness of the analogy experiment method. Using 3 different anode size and 6 different geometrical configurations, the effects of the anode size and position were explored. As expected, the anode size and position do not affect the limiting currents for most cases. These results will be used as the experimental background for the positioning and sizing of the anodes for a more complex experiment.

• Analytical Science and Technology
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• v.31 no.2
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• pp.71-77
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• 2018

Detection of bloodstains is a very important process in scientific investigations, and luminol is often used for the detection of bloodstains that are not visible. Recently, new preparation methods of blood detection reagents based on luminol (BloodFlareA, B) were developed and reported to have higher active persistence and to be more economical than conventional blood detection reagent, BlueStar forensic. In this paper, we tested the specificity and effect of the BloodFlares (A and B) on DNA and compared them with those of BlueStar forensic. False positive results for the BloodFlares were not observed in semen, saliva, vaginal fluids, urine, sweat, and nasal discharge, but were observed in $CuSO_4$, $FeSO_4$, and bleach solutions, and the observed patterns were similar to those of BlueStar forensic. The effect on DNA was determined by analyzing the DNA yield, degradation index, and DNA profiling. Based on these results, we concluded that the BloodFlares based on luminol do not affect DNA stability and are applicable in forensics.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1357-1364
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• 2000

Our study was performed to evaluate the effect of leaching parameters including the physicochemical characteristics and the fractionated composition of heavy metals on the release of heavy metals in fly ash discharged from MSWI. Leaching parameters such as pH, CEC, particle size, and exchangeable fraction among the fractional composition classified by sequential extraction procedure are considered. The leaching rate of heavy metal released by KSLT method is largely dependent on the pH of fly ash. The effect of pH on the release of heavy metals is different from elements. It appears that the leaching rate of cadmium and copper decreases with increasing pH, while lead and zinc increases at the condition of neutral or strong alkali condition, which suggests that the leaching of heavy metals are limited by the solubility. It is found that the effect of CEC is similarly to that of pH, $D_{10}$ among the particle size of fly ash is negative correlated with the concentration of heavy metals leached by KSLT method. In the case of exchangeable fraction, the leaching rate of heavy metals is linearly correlated with the exchangeable fraction for the fly ash below 40 meq/l00g of CEC, but not related out of the range.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.2
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• pp.42-53
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• 2020

In this study, heavy metal in road-deposited sediments (RDS) and marine sediment around Gwangyang Bay area have been investigated to assess the pollution status of metals and to understand the environmental impact of RDS as a potential source of metal pollution. Zn concentration for <63 ㎛ size fraction was the highest (2,982 mg/kg), followed by Cr, Ni, Pb, Cu, As, Cd, and Hg. Metal concentrations in RDS increased with decreasing particle size and relatively higher concentrations were observed around the metal waste and recycling facilities. For particle size in RDS smaller than 125 ㎛, EF values indicated that Zn was very high enrichment and Cr, Cd, Pb were significant enrichment. The concentrations of metals in marine sediments were mostly below the TEL value of sediment quality guidelines of Korea. However, the Zn concentrations has increased by 30~40% compared to 2010 year. The amounts of Zn, Cd and Pb in less than 125 ㎛ fraction where heavy metals can be easily transported by stormwater runoff accounted for 54% of the total RDS. The study area was greatly affected by Zn pollution due to corrosion of Zn plating materials by traffic activity as well as artificial activities related to the container logistics at Gwangyang container terminal. The fine particles of RDS are not only easily resuspended by wind and vehicle movement, but are also transported to the surrounding environments by runoff. Therefore, further research is needed on the adverse effects on the environment and ecosystem.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1350-1357
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• 2017

General component and mineral contents according to species of Capsicum annuum were investigated. In addition, chuichung cucumber, white dadagi cucumber, and yellowish overripe cucumber were cooked by using seven different methods (boiling, steaming, pan-cooking, roasting, pan-frying, deep-frying, and microwaving), and retention rates of general components and minerals according to species were evaluated. Weight loss was observed in all cucumber species using all cooking methods. Most general component and mineral contents of C. annuum samples were significantly different according to species, and cooking method (P<0.05), whereas Fe and Cu contents were not significantly affected by species and cooking method, respectively. As a result, the highest protein, fat, ash contents were detected in deep-fried C. annuum, and high moisture contents were detected in raw, boiled, and steamed C. annuum. High mineral contents were detected in roasted and microwaved chuichung cucumber, deep-fried white dadagi cucumber and yellowish overripe cucumber. Retention rates of C. annuum by cooking method, ranged from 30~100% for protein, 10~100% for fat, 35~90% for moisture, and 30~100% for ash. High retention rates were observed for minerals in boiled, roasted, and microwaved chuichung cucumber, and deep-fried white dadagi cucumber and yellowish overripe cucumber. However, in yellowish overripe cucumber, mineral retentions rate were remarkably lowered by boiling and steaming, resulting in rates of 20~45%. These results were the data used as the basis for development of cucumbers.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.272-280
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• 2018

Existing toxicity assessment researches were rarely studied on assessment of the abnormal behavior that affecting survival. Therefore, the study used anti-predator response of amphibians larvae, based on behavioral understanding, to assess toxicity in fullerene nanowhisker(FNW) and fullerene nanowhisker-silver nanoparticle composites(FNW-Ag). The experiment was conducted by dividing the groups not exposed to nanomaterials and exposed to nanomaterials at five concentrations(FNW: $10{\mu}g/ml$, FNW: $100{\mu}g/ml$, FNW: $500{\mu}g/ml$ FNW-Ag: $10{\mu}g/ml$, FNW: $50{\mu}g/ml$). As a result, there were no differences in normal activity except those exposed to concentrations of FNW-Ag $50{\mu}g/ml$, but there were statistically significant differences in anti-predator response except those exposed to concentrations of FNW $10{\mu}g/ml$. That is, exposed of nanomaterials does not affect ordinary movements, but analyses based on behavioral understandings have shown that it has an influence on the anti-predator response. It is therefore considered necessary to have animal behavioral analysis method performed in the assessment of eco-toxic experiment.

• Clean Technology
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• v.26 no.3
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• pp.196-203
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• 2020

In this study, a Cu/hexaaluminate catalyst was prepared by a co-precipitation method, and then a binder was added to form a pellet. A catalyst in which Ni and Ru promoters were added to a Cu/hexaaluminate pellet catalyst was prepared. This study focused on examining the effect of the addition of Ni and Ru promoters on the properties of Cu/hexaaluminate catalysts and the decomposition reaction of ADN-based liquid monopropellants. Cu/hexaaluminate catalysts had few micropores and well-developed mesopores. When Ru was added as a promoter to the Cu/hexaaluminate pellet catalyst, the pore volume and pore size increased significantly. In the thermal decomposition reaction of ADN-based liquid monopropellant, the decomposition onset temperature was 170.2 ℃. Meanwhile, the decomposition onset temperature was significantly reduced to 93.5 ℃ when the Cu/hexaaluminate pellet catalyst was employed. When 1% or 3% of Ru were added as a promoter, the decomposition onset temperatures of ADN-based liquid monopropellant were lowered to 91.0 ℃ and 83.3 ℃, respectively. This means that the Ru promoter is effective in lowering the decomposition onset temperature of the ADN-based liquid monopropellant because the Ru metal has excellent activity in the decomposition reaction of ADN-based liquid monopropellant, simultaneously contributing to the increase of the pore volume and pore size. After the thermal treatment at 1,200 ℃ and decomposition of ADN-based liquid monopropellant were repeatedly performed, it was confirmed that the addition of Ru could enhance the heat resistance of the Cu/hexaaluminate pellet catalyst.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.826-833
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• 2005

This study was conducted to inform basic data for management of abandoned mine that was based on soil heavy metal concentration of the non-rearing and the rearing sites in Guundong Mine which had been completed of improve contamination soils, and examined into standard plant which had tolerances about pollution that analyzed into its accumulated heavy metals contents in the wild plant of naked soil. Consider form the result of contents by depth of soils heavy metals in the non-rearing sites, S1 point judged by contaminated to heavy metals of tailing leach after weathering caused by rainfall and permeate in S1 point soils when restored rest of tailing in 1996 restoration project. Lead of S2 point was not contaminated seriously by restoration and S3 point considered that heavy metals which leach by rainfall in the contaminated soils in mine vicinity accumulated in the abandoned paddy through river When heavy metals of rearing sites soils were examined from the view point of upside of mine point (SP1, SP2, and SP3) of same above the sea level, zinc (537.5 mg/kg) content of SP1 point was highest, and copper (535 mg/kg) and lead (141.5 mg/kg) in the SP3 point were high. To considered as orderly plenty of heavy metals in the plant were respectively in order, Perilla frutescens var. cauta KUDO (SP1 and SP4) >Artemisia princeps PAMPAN (SP2) > Miscanthus sinensis ANDERSSON(SP5) > Vicia angustifolia var. segetilis (THUILL.) K. KOCH. (SP2). Especially, there were plenty of heavy metals in P. frutescens var. acuta, so it judged as a standard plant which have tolerances about heavy metals pollution sites. Therefore, we need more study about the heavy metals accumulate ability of P frutescens var. acuta in future.