• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.20-20
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• 2003

용융아연도금은 내식성 아연코팅목적으로 산업체에서 광범위하게 사용되고 있다. 이 공정에서 아연의 배출성능이 나쁜 관계로 피처리물의 끝부분에 고드름이 생기거나 작은 구멍을 메우는 문제가 종종 발생한다. 본 연구에서는 용융아연욕에 Bi를 단독 첨가하거나 Bi와 AI을 함께 첨가하여 이 문제를 해결하였다. Bi의 첨가는 아연의 배출성능을 현저하게 증가시켰으며 0.1 wt.% Bi, 0.025~0.05 wt.% AI을 함유한 용융아연욕에서 가장 균일성이 좋은 코팅층을 얻을 수 있었다. 산업현장 적용시험 결과 아연의 수율을 향상시켰고 드로스의 형성량이 감소하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.48-48
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• 2018

습도는 대기중에 분포되어있는 물 분자의 양으로 사람이 살아가는데 있어 막대한 영향을 주는 환경적 요소중 하나이다. 산업적 가스의 순도에 막대한 영향을 끼치기도 하고, 반도체 산업에서 불량률과도 밀접한 관련이 있다. 또한, 식품학이나 기상학, 농사와도 밀접한 관련이 있어서 습도를 측정하는 것은 중요시 되고 있다. 이를 위해서 많은 물질들이 사용되고, 연구되었다. 산화 구리, 산화 아연, 산화 납 등의 산화금속 물질들이나 전도성 고분자, 실리콘 기반의 물질들이 주로 사용되고 있는데, 그 중 산화 금속이 쉬운 합성 방법과 낮은 단가, 명확한 작동 원리로 인해 널리 사용되고 있다. 산화 아연의 경우 넓은 direct band gap energy와 우수한 내화학성으로 인해 주로 사용되는데 그 중 1차원 물질인 nanowire의 경우 비등성 구조와 높은 비표면적을 갖는 특성으로 인해 산화 아연의 nanowire 구조가 많이 사용된다. 본 연구에서는 열처리 공정을 이용하여 산화아연의 nanowire 구조를 합성하였고, 합성된 nanowire는 양쪽의 미세전극을 직접적으로 연결하여 간편한 방식으로 소형 소자를 만들 수 있다는 장점이 있다. 열처리 공정 이전에 전기도금 방식을 이용하여 아연층을 증착 하였다. 전기도금 조건은 0.1 M의 염화 아연과 1 M의 염화 칼륨으로 구성된 용액에 -1.1 V를 인가하였다. 합성된 아연층은 열처리 공정에 의해 산화아연의 nanowire 구조체로 변환되고, SEM (scanning electron microscope)를 통해 표면 형상을 관찰 하였고, XRD (X-ray diffraction)을 통해 미세구조를 확인하였다. -1 V부터 1 V 범위의 전압을 흘려주어 형성된 소자의 전기적 특성을 확인하였고, 1 V를 인가하였을 때, 습도 변화에 따른 센서 소자의 저항변화를 통해 습도 센서로서의 특성을 확인 하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.574-580
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• 1994

The effect of dietary zinc(Zn) levels on cadmium (Cd)-induced hepatotoxicity was studied in serum and liver of rats. Adult male Spraque-Dawley rats were fed on diets containing one of three levels of zinc carbonate(0, 56, $560\mu\textrm{g}/kg$ diet) and Cd-treated groups were administrated oral intubation with cadmium chloride 95.0 mg/kg of body weight) at the sametime once a week. Net weight gain (NWG), feed intake (FI) and feed effciiency ratio (FER) in Zn deficiency groups significantly decreased as compared to that of control and excessive groups. Cd oral intubation caused a decrease in NWG and FI but an increase in Zn deficiency group in FER. GSH-Px, GST and catalase activity showed significant decrease in Zn deficiency and Zn excessive group. LPO content in liver significantly increased in Zn deficiency group. Cd oral intubation increased the content of LPO in Zn deficiency group as compared to control. GSH content and GST activity of hepatic tissue significantly decreased in Zn deficiency and excessive group. The activity of AST and ALT in serum were markedly increased in Zn deficiency, Zn excessive and Cd-treated groups. LDH and ALP activities significantly increased in Cd-treated group while ALP activity decreased by Zn deficiency. It was observed that the livers of rats exposed to Cd and Zn excessive group showed a marked increase of hepatic enzyme as compare to only Cd-treated in rats.

• The tire
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• s.75
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• pp.15-23
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• 1978

금속염을 첨가한 고무를 아연판과 접착가황하여 아연면의 첨가금속과 유황의 분포를 XMA에 의해 구했다. 가황중에 아연면으로 이행하는 것은 Co, Cu, Pb를 포함한 유기금속염뿐이였다. 고무 속의 유리유황도 이들 금속염과 함께 아연판으로 이행되어 왔다. 나프텐산코발트 중의 Co는 아연층내에 확산되어 분포된 데 반하여, S는 아연판표면에만 분포되어 있다. 양자가 아연판으로 이행되는 양은 첨가량에 비례해서 증가하였다. 고무와 아연판의 접착력은 Co량 0.6%까지는 증가하고, 그 이상의 첨가에서는 현저하게 저하되었다. 나프텐산코발트의 첨가량을 증가시키면 가황고무 중의 망목쇄농도는 변하지 않으나 유리유황은 감소하였다. 가황고무 중의 잔류나프텐산코발트는 60℃이상의 열처리온도에서 산화를 촉진하고 접착력도 저하시킨다. 카아본블랙을 배합하지 않은 NR의 유전거동보다 첨가한 나프텐산코발트는 가황온도에서 고무 분자의 주쇄 Segment의 완화 mode에 영향을 준다는 것을 알았다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1174-1178
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• 2009

The purpose of this study was to investigate the effect of dietary zinc levels on carbohydrate metabolism and serum zinc, magnesium and chromium contents in obese rats. Animals were divided into three groups by zinc levels, such as low (15 ppm), adequate (30 ppm) and high (60 ppm) levels of dietary zinc. The food intake, weight gain and feed efficiency ratio were not changed by zinc levels. There were no significant differences in liver, kidney and spleen weights. However, serum glucose concentration significantly decreased as the levels of dietary zinc increased, in particular, that of obese rats fed the high level of zinc was remarkably decreased. Insulin concentration of rats fed high level of zinc diet was significantly higher than that in the other groups. However, there were no significant differences in serum zinc and chromium contents, although serum magnesium fed zinc deficient diet was significantly higher than that of the other two groups. Glucose concentrations had negative correlation with insulin concentrations, and positive correlations with serum magnesium content. In conclusion, serum glucose concentrations were decreased and insulin concentrations were increased as the levels of dietary zinc increased in obese rats. These results suggested that zinc supplement at higher level than adequate one would increase insulin concentration and may improve hyperglycemia problem in obese groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1037-1041
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• 2009

The effect of dietary zinc levels on macro mineral contents was investigated in rats. Rats were divided into three groups by zinc levels, such as low (50% of requirement, Zn/L), adequate (100%, Zn/A) and high (200%, Zn/H) levels of dietary zinc. The calcium, magnesium, sodium and potassium contents in serum and organs were measured. The food intake was significantly higher in Zn/L group compared to that of Zn/H group. The body weight gain in Zn/H group was significantly lower than that of other two groups. There were no significant differences in liver, kidney and spleen weights. Also, serum calcium, magnesium, sodium and potassium concentrations were not significantly changed by the zinc diet at any level. In the low zinc diet group, liver calcium content was significantly lower, but the magnesium and potassium contents in spleen were significantly higher than that in other groups. The calcium, magnesium, sodium and potassium contents of kidney were not significantly different for any level of zinc. In conclusion, the macro mineral contents of liver and spleen in the normal rats were changed by zinc levels. Based on this study, the interaction between micro and macro minerals remains to be further studied.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.6
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• pp.240-246
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• 2021

In the ceramic industry, a drastic decrease in crystalline formation was found even among the glazes well known for their high crystalline productivity when the ceramic glaze was stored in wet conditions over a period. This study aimed to investigate the reason for decreasing willemite crystals during storage. As the starting materials ZnO, calcined ZnO and frit 3110 are selected; the composition for zinc crystalline glazes was set through a three-component system with the materials. The firing condition was used from previous studies. The study was observed how wet conditions affected the crystallization of zinc crystalline glazes from a day to 24 weeks. The results were obtained by particle size analysis, XRD, Raman spectroscopy and SEM analysis. The results indicated that ZnO is advantageous in terms of willemite crystalline development and growth; however, Zn(OH)₂ cluster, formed by the reaction with water during the storage, caused the decrease in ZnO level in the glaze. The reduction of ZnO in the glaze eventually interfered the willemite development and growth.

• Resources Recycling
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• v.1 no.1
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• pp.58-68
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• 1992

A process development for direct synthesis of high pure ZnO powders from zinc-bearing waste was investigated. This waste contains a 55% of zinc and it was extracted by the sulfuric acid(leaching). After removal of iron ion by precipitation from the zinc solution, the purification through a solvent extraction by the use of D2EHPA as an extractant was carried out. Then, loaded zinc in organic solution was stripped and precipitated simultaneously using a precipitant such as oxalic acid. Then, loaded zinc in organic solution was stripped and precipitated simulataneously using a precipitant such as oxalic acid. The synthesized $ZnC_2O_4$ powders by the precipitation stripping method was calcined to obtain more than 99.9% of ZnO powders. The effect of sulfuric acid concentration, leaching time, pulp density on the extraction of zinc was studied and the optimum conditions for the solvent extraction were obtained through the investigation of purification of zinc solution. The size, morphology and size distribution of synthesized $ZnC_2O_4$ powders were studied in terms of oxalic acid concentration, temperature, surfactant added, precipitation time, etc.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.34.2-34.2
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• 2007

• Proceedings of the Korean Nutrition Society Conference
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• 1996.06b
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• pp.58-58
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• 1996