• 한국표면공학회지
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• 제12권3호
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• pp.174-179
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• 1979

The effects of brightness, electrochemical behaviour on the organic additives, such as aldehydes, polymers, amines and condensed product obtained from epichlorohydrin and nicotinamide, in cyanide zinc electrolplating bath have been studied by controlled potential electrolyser. The results were summerized as follows: (1) It was found that the addition of only one compound of these organic compounds in the bath was unsuitable but mixture of anisaldehyde or monoethanolamine and condensed product as suitable as brightener. (2) The cathodic polarization curve of polymers or aldehydes in cyanide zinc electroplating bath was almost the same but the cathodic polarization curve of condensed product remarkable shifted to noble potential more than non-additive curve.

• 한국표면공학회지
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• 제32권2호
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• pp.157-164
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• 1999

In this study the effect of nickel addition on the coating weight of mini-mill steels containing silicon has been studied. It is shown that the pure zinc accelerated growth of the alloy layers occurred by a rapid growth of the zeta phase at 0.06%Si. The addition of 0.06%Ni to a pure zinc bath was found to be very effective in reducing the coating weight and promoting preferential development of the delta phase. The coating obtained by immersion in the Zn-Ni bath shows the presence of a nickel-rich region between the zeta phase and the eta phase. It is suggested that nickel prevents the rapid growth of the zeta phase due to the formation of the Zn-Ni-Fe ternary compound, which may act as a barrier to inward diffusion of zinc or iron at the zeta-eta boundary.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.825-835
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• 2020

Objective: The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C₇) and 120 days (C₁₂₀) of ripening. Methods: Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (zinc group, ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile. Results: The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones. Conclusion: The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes.

• Corrosion Science and Technology
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• 제9권2호
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• pp.98-103
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• 2010

In order to further reduce the cost without reducing the corrosion resistance, a high-manganese austenitic alloy for sink roll or stabilizer roll in continuous hot-dip coating lines was developed. A systematic study of corrosion behavior of the high-manganese austenitic alloy in pure zinc bath at $490^{\circ}C$ was carried out. The results shows that, the high-manganese austenitic alloy shows better corrosion resistance than 316L steel. The corrosion rate of the high-manganese austenitic alloy in pure zinc bath is calculated to be approximately $6.42{\times}10^{-4}g{\cdot}cm^{-2}{\cdot}h^{-1}$, while the 316L is $1.54{\times}10^{-3}g{\cdot}cm^{-2}{\cdot}h^{-1}$. The high-manganese austenitic alloy forms a three-phase intermetallic compound layer morphology containing ${\Gamma$}, ${\delta}$ and ${\zeta}$ phases, while the 316L is almost ${\zeta}$ phase. The ${\Gamma}$ and ${\delta}$ phases of the high-manganese austenitic alloy contain about 8.5 wt% Cr, the existence of Cr improve the stabilization of phases, which slow down the reaction of Fe and Zn, improve the corrosion resistance of the high-manganese austenitic alloy. So substitute the nickel with the manganese to manufacture the high-manganese austenitic alloy of low cost is feasible.

• 대한화장품학회지
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• 제35권1호
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• pp.11-17
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• 2009

스테로이드 함유 표시가 없는 화장품에서 항염증 효과가 있는 글루코코티코스테로이드인 베타메타손프로피오네이트 성분이 검출되었다. 이 화장품은 외용스프레이 및 샴푸로서 주성분으로 아연피리치온을 함유하는 것으로 표기되어 있었다. 화장품에서 스테로이드 구조와 활성을 갖는 물질의 존재를 확인하기 위하여 실리카겔 박층판을 이용한 박층크로마토그래프를 사용하였으며 이 성분을 분리하기 위해 high-performance liquid chromatography (HPLC)를 이용하여 확인 및 정량을 수행하였다. 분취용 HPLC를 이용하여 스테로이드를 함유한 것으로 판단되는 분획을 모은 다음 nuclear magnetic resonance (NMR) 및 mass spectrometry (MS)를 이용하여 스테로이드 성분을 확인하였다. 스테로이드 표준물질로 베타메타손 17-프로피오네이트 및 베타메타손 21-프로피오네이트를 합성하여 사용하였고 이 표준물질과 HPLC 크로마토그램을 비교하여 스테로이드 성분의 함량을 분석하였다. 이 방법으로 아연피리치온 제제와 같은 일부 시판 화장품에서 스테로이드 성분을 확인하였고 reversed-phase high-performance liquid chromatography (RP HPLC) 상의 유지시간 비교를 통하여 스테로이드 성분을 정량한 결과 시험한 총 8종의 화장품 시료 중 2개 제품에서 0.005 ${\sim}$ 0.02%의 베타메타손프로피오네이트가 검출되었다.

• Tribology and Lubricants
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• 제11권1호
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• pp.50-57
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• 1995

When engine oil is used under severe running condition, the Lubricational characteristics is very important. I have studied the Lubricational characteristics with Compound Additives of engine oil for the Falex wear test machine. Adding detergent (Ca-phenate) to engine oil, the seizure is more improved than in case of non-adding, and adding Zn-DTP (Zinc dialkyl dithio phosphate), the extreme pressure property is excellent at the high load. But when the PTFE (Polytetra Fluoro Ethylene) and MoS$_{2}$ (Molybdenum disulfide) are added, the temperature characteristics and the anti-wear property become excellent because the stability can be maintained in a high temperature. The result are as follows, it can be improved that when the compound of the Ca-phenate and Zn-DTP, MoS$_{2}$, PTFE, etc. was added to engine oil, the lubrication characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreame pressure properties and the heat stability.

• 대한화학회지
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• 제62권1호
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• pp.14-18
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• 2018

The complexes $[Zn(L)(H_2O)_2]{\cdot}2NO_2$ (1) and $[Zn(L)(NO_3)_2]$ (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo $[14,4,0^{1.18},0^{7.12}]$docosane) have been synthesized and structurally characterized. The compound 1 crystallizes in the monoclinic system $P2_1/c$ with a = 8.74650(10), b = 18.6880(3), c = $7.96680(10){\AA}$, ${\beta}=109.1920(10)^{\circ}$, $V=1229.84(3){\AA}^3$, Z = 2. The compound 2 crystallizes in the monoclinic system P1 with a = 8.1292(5), b = 8.9244(5), c = $9.1398(5){\AA}$, ${\alpha}=68.035(2)$, ${\beta}=70.109(2)$, ${\gamma}=75.649(3)^{\circ}$, $V=572.70(6){\AA}^3$, Z = 1. The crystal structures of the compounds 1 and 2 show a distorted octahedral coordination geometry around the zinc(II) ion, with four secondary amines and two oxygen atoms of the two water and two nitrate ligands at the axial position. The TGA behaviors of the complexes are significantly affected by the nature of the tetraaza macrocycle and the axial ligands.

• Corrosion Science and Technology
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• 제6권4호
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• pp.147-153
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• 2007

This study sought to investigate the reaction of Co-binder containing tungsten with molten zinc. Four kinds of Co-W alloys (pure, 10%W, 20%W, 30%W) were prepared using the powder metallurgy method. The specimens were immersion-tested in molten pure zinc baths at $460^{\circ}C$. To evaluate the corrosion property in molten zinc, the weight loss of the specimen was measured after the immersion tests at different immersion times (10~300 min.). Co-10%W alloys, compared with pure cobalt, showed no effect of tungsten addition on the reaction rate in molten zinc. The relationship between the weight loss and the square root of immersion period represents a straight line in both pure cobalt and Co-10%W alloy. The Co-Zn reaction layer in Co- 1O%W alloy consists of $\gamma2$, $\gamma1$, $\gamma$ and ($\beta1$ phases. The rate of weight loss significantly increases and the weight loss behavior is not well accord with the linear relationship as the tungsten content in the Co-W alloy increases. The $\beta1$ layer was not formed on the Co-20%W alloy and neither was a stable Co-Zn intermetallic compound layer found on the Co-30%W alloy. The main cause of increase in reaction rate with increasing tungsten content is related with the instability of the Co-Zn reaction phases as seen on micro-structural analysis.

• 한국가스학회지
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• 제9권4호
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• pp.26-29
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• 2005

본 연구에서는 Metallophthalocyanine Macrocyclic Compounds인 Zinc phthalocyanine(ZnPc)를 이용하여 박막 films를 만들어 solvent sensor의 특성에 대한 연구을 수행하였다. 측정에 사용한 유기용제의 종류는 Acetic acid, Ethyl alcohol, Methyl alcohol, Ammonia 및 1,1,1-trichloroethane이였으며, solvent sensing 특성으로는 전기저항 변화를 측정 분석하였다. 또한 Zinc phthalocyanines과 $N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,\;1-biphenyl-4,4'-diamine\;and/or\; Poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene]$를 blend하여 spin-coating, evaporation박막을 만들어 유기용제 농도에 따라서 전기 저항 변화를 측정 분석하였다.

• 전기화학회지
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• 제14권3호
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• pp.145-151
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• 2011

ZnSe는 가시광선 영역에서 넓은 밴드갭을 가지고 있는 II-VI족 화합물 반도체 소자로서 레이저 다이오드, 디스플레이 그리고 태양전지와 같은 다양한 응용분야에 적용되고 있다. 본 연구에서는 전기화학적 전착방법을 이용하여 ITO 전극상에 ZnSe 박막을 합성하여, XRD와 SEM으로 ZnSe 결정의 합성과 zinc blende 구조의 형태를 관측하였고, UV 분광기를 활용하여 밴드갭을 측정한 결과 2.76 eV이었다. 또한, 분자동역학에서 활용되는 밀도범함수 이론 (DFT, Density Functional Theory)을 도입하여 ZnSe 결정에 대한 밴드 구조의 해석을 수행하였다. Zinc blende구조를 갖는 ZnSe 결정에 대하여 LDA (Local Density Approximation), PBE (Perdew Burke Ernzerhof), 그리고 B3LYP (Becke, 3-parameter, Lee-Yang-Parr) 범함수를 이용하여 밴드구조와 상태밀도 (Density of State)를 모사하였다. 각각의 경우에 대해 에너지 밴드갭을 구한 결과, B3LYP 범함수로 해석한 경우에 실험치와 근사치인 2.65 eV의 밴드갭을 보여주었다.