• Clean Technology
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• v.19 no.3
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• pp.249-256
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• 2013

The experiments have been performed to obtain zinc complex compound with smaller particle sizes, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation and the triboelectric charge of zinc complex-compound particle with different sizes. Reactants such as zinc chloride and 3,5-di-tert.-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Aluminium(III) chloride has been mixed in the zinc chloride solution beforehand to restrain the particle size from growing. When PEG-300 and aluminium(III) chloride are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from $5.28{\mu}m$ to $2.33{\mu}m$, which was 44.1% of $5.28{\mu}m$.

• Polymer(Korea)
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• v.28 no.2
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• pp.185-193
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• 2004

Elastomeric nanocomposites were prepared by employing zinc dimethacrylate into an acrylonitrile-butadiene rubber, and their network structures, mechanical properties, and fracture morphologies were investigated according to the adding methods and contents of zinc dimethacrylate. The total crosslink density increased with increasing the zinc dimethacrylate level, due to increased ionic bonds. Both the tensile strength and tear strength increased with increasing zinc dimethacrylate loadings, and then decreased after reaching a maximum value. It was found that the tear strength and crack resistance were greatly affected by the mixing method of zinc dimethacrylate. The in-situ nanocomposites, where zinc dimethacrylate particles were formed by the reaction of zinc oxide and methacrylic acid, showed much improved tear strength and crack resistance compared to those of the nanocomposites based on the direct mixing of zinc dimetacrylate powders. This was because of the finer zinc dimethacrylate particles and improved dispersion of the in-situ nanocomposites.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.63-65
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• 2004

아연도금강판은 일반 냉연강판에 비해 내식성과 내구섣이 우수하여 자동차, 토목, 건축, 가전산업 등 여러 분야에 널리 사용되고 있다. 그러나 저항용접 시 낮은 용점의 아연이 전극을 오염(Pick up)시켜 적정 용접전류가 높아지고 연속타점 시 저극의 오염으로 인해 날림(Splash)를 발생시켜 작업환경과 모재에 악영향을 주고있다. (중략)

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.489-497
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• 2018

Purpose: Obesity is often associated with disturbances in the mineral metabolism. The purpose of this study was to investigate the effects of high-fat diet-induced obesity on tissue zinc concentrations and zinc transporter expressions in mice. Methods: C57BL/6J male mice were fed either a control diet (10% energy from fat, control group) or a high-fat diet (45% energy from fat, obese group) for 15 weeks. The zinc concentrations in the serum, stool, and various tissues were measured by inductively coupled plasma (ICP)-atomic emission spectrophotometry or ICP-mass spectrophotometry. The levels of zinc transporter mRNAs in the liver, duodenum, and pancreas were measured by real-time RT-PCR. The levels of serum adipokines, such as leptin and IL-6, were determined. Results: The total body weight, adipose tissue weight, and hepatic TG and cholesterol concentrations were significantly higher in the obese group, as compared to the control group. The obese group had significantly higher levels of serum leptin and pro-inflammatory IL-6 concentrations, and had significantly lower levels of serum alkaline phosphatase activity. The zinc concentrations of the liver, kidney, duodenum, and pancreas were all significantly lower in the obese group than in the control group. On the other hand, the fecal zinc concentrations were significantly higher in the obese group than in the control group. The serum zinc concentrations were not significantly different between the two groups. The ZnT1 mRNA levels of the liver and the pancreas were significantly higher in the obese group, as compared to the control group. Hepatic Zip10 mRNA was also increased in the obese group. Conclusion: Our study findings suggest that obesity increases fecal zinc excretion and lowers the tissue zinc concentrations, which may be associated with alterations in the zinc transporter expressions.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.47-54
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• 1979

A field experiment has been carried out to evaluate the residual effect of zinc fertilizers by rice plant grown under flooded conditions in the field. The results obtained are summarized as fellows ; Residual effect of zinc fertilizers on yields of rough and hulled grains showed slight increases. Effect of zinc application methods on yields of the grains were shown that zinc mixed treatment could be more effectively utilized than treatment of zinc on the soil surface. In case of levels of zinc application, 5 kg zinc per hectare represented high yields of the grains than those obtained from 10kg and 20kg zinc placement per hectare respectively. Regarding the form of zinc fertilizers, the urea-zinc complex showed less effective on yields of the grains than did the zinc sulfate. This phenomenon was consistent with the previous result. Yields of total zinc in rice plant grown on the rice straw added soils (Treatment No. 2 and 8) and the urea-zinc complex treated soil were increased markedly as compared to those data obtained from the previous year. The percentage of zinc derived from fertilizer decreased largely as compared to that of the first year crop. The yield of fertilizer zinc in rice plant decreased slightly in the most zinc treatments but in the case of treatments of zinc mixed with the straw added soil and the urea-zinc complex increased reversely as compared to the previous results. The mixed application of zinc with soil showed higher yield of fertilizer zinc than the soil surface placement. Approximately from 4.6 to 24.3 per cent of zinc taken up by rice plants were derived from the fertilizer zinc. Zinc fertilizer use efficiency ranged from 0.213 to 0.584 per cent when 5 kg zinc per hectare applied.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.8-13
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• 2012

The experiments have been performed to obtain zinc complex compound with smaller particle size, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation of different sizes of zinc complex-compound particle. Reactants such as zinc chloride and 3,5-di-tert-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Zirconium (IV) oxychloride octahydrate has been mixed in the zinc chloride solution beforehand to restrain crystals from growing. When PEG-300 and zirconium (IV) oxychloride octahydrate are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from 5.28 to 1.84 ${\mu}m$, which is 34.9% of 5.28 ${\mu}m$.

• Resources Recycling
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• v.16 no.6
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• pp.39-45
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• 2007

Optimum condition for neutralization has been studied to remove the copper and zinc ions from spent sulfate solutions which resulted from the acid washing of the base of brass bulb. Chemical distribution of copper and zinc species and the variation of solubility of the two ions with solution pH were obtained by considering the complex formation reaction and mass balance. Removal percentage of zinc was more sensitive to solution pH than that of copper. This results from the fact that the solubility of zinc is higher than that of copper. The form of coagulant affected little the removal percentage of zinc, while addition of coagulant as the phase of solution resulted in higher removal percentage of copper than as the phase of solid.

• Elastomers and Composites
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• v.49 no.3
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• pp.191-198
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• 2014

We synthesized thermoplastic polyurethane elastomer(TPU) with acid group and nano zinc oxide, and characterized their mechanical properties, thermal properties, contact angle and grip property. The effects of the zinc oxide content and size on the physical property of TPU were investigated. When the nano zinc oxide was introduced in TPU with acid group, it had excellent mechanical properties and grip by formation of hydrogen and ionic bonding. The wet slip of TPU with zinc oxide was increased continuously as ionization rate increased due to increase of hydrophilicity and ionic interaction, and mechanical properties were increased with increasing ionization rate up to 50%.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.13-26
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• 2002

In this study, column diffusion tests for Cd and Zn were conducted at $15^{\circ}C$ and $55^{\circ}C$ to investigate a temperature effect on effective diffusion coefficient. An increase in temperature from $15^{\circ}C$ to $55^{\circ}C$ caused up to ten times larger diffusion coefficient for each heavy metal. Besides, it caused the increased retardation of heavy metals, and hence the effective diffusion coefficient should be overestimated as we use an overestimated retardation factor to calibrate the coefficient. The results of sequential extraction analyses showed that Zn was occluded in carbonate phase and this trend was getting prominent with the increase in temperature. As for Cd, it was partitioned mainly in the exchangeable phase(over 60%) at any temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.603-610
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• 2017

Steel used for various industrial fields including ammunition is vulnerable to corrosion so surface treatments are required such as plating, painting and chemical conversion coating. Zinc phosphate, used for ammunition manufacturing, is used to stick the stable compound on the surface by chemical conversion of metal. The quality of phosphate coating depends on many factors such as total acidity and iron content. In this study, we studied the influence of total acidity and iron content on coating weight and corrosion resistance of phosphate coating. The surface structure of the coating becomes dense and corrosion resistance is improved with increasing iron content. However, total acidity influences only the thickness and phosphate coating weight. In conclusion, this study suggests the optimal range of total acidity and iron content to manufacture the ammunition.