• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.235-235
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• 2011

ZnO 나노구조체를 성장하는 여러 가지 방법 중에서 전기 화학 증착법은 컨트롤이 용이하며 저렴한 가격으로 낮은 온도에서 성장이 가능할 뿐만 아니라 대면적으로 성장할 수 있는 장점이 있다. 나노구조체의 직경과 길이는 indium-tin-oxide와 Ag/AgCl 전극 사이의 전류 밀도 증가에 따라 변화하는 것을 알 수 있었다. Zinc nitrate 몰 농도를 조절하여 다양한 형태의 ZnO 나노구조체를 만들 수 있었다. 70$^{\circ}C$에서 4시간 동안 성장한 ZnO 나노구조체를 대기에서 400$^{\circ}C$로 2분 동안 열처리를 하였다. 성장된 ZnO 나노구조체에 대한 X-선 회절 측정 결과로부터 (0002) 피크가 34.35$^{\circ}$에서 나타나는 것을 확인하였다. 주사전자현미경 측정 결과로부터 zinc nitrate의 몰 농도가 낮을 때 성장한 ZnO 나노구조체는 와이어 형태로 형성되었음을 확인하였다. 그러나 zinc nitrate의 몰 농도가 높아지게 되면 ZnO 나노구조체의 모양이 와이어에서 막대 또는 접시 형태로 변화 되는 것을 알 수 있었다. 300K에서의 광루미네센스 스펙트럼 결과로부터 zinc nitrate의 농도에 따라 다르게 형성된 ZnO 나노구조체는 엑시톤과 관련된 피크가 zinc nitrate의 몰 농도 변화에 따라 달라지는 것을 확인 하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.97-103
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• 1999

Zinc sulfide is a ll-VI compound with a large direct band gap in the near-UV region and a promising material for blur-light emitting diode and laser diode. It was identified that the structure had zinc blonde structure through the analysis of X-ray diffraction patterns. It's lattice constant was measured to be $a_o=5.411{\AA}$. The optical absorption, photocurrent, and photoluminescence spectra were measured to investigate the optical properties of zinc sulfide single crystal. The optical energy band gap measured at room temperature was 3.61eV The energy band gap of zinc sulfide annealed in zinc vapor at $800^{\circ}C$ was lower 0.1eV than that of as-grown zinc sulfide through the analysis of the photocurrent spectra. The photoluminescence spectra were measured ranging from 30K to 293K for the two cases of as-grown and annealed zinc sulfide. As-grown ZnS single crystal had peaks at 350nm, 392nm, 465nm, and annealed zinc sulfide had peaks at 349nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.2
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• pp.104-110
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• 2001

Structural, optical and electrical properties of Cd$_{1-x}$ Zn$_{x}$S films deposited by chemical bath deposition(CBD), which is a very attractive method for low-cost and large-area solar cells, are presented. Especially, in order to control more effectively the zinc component of the films, zinc acetate, which was used as the zinc source, was added in the reaction solution after preheating the reaction solution and the pH of the reaction solution decreased with increasing the concentration of zinc acetate. The films prepared after preheating and pH control had larger zinc component and higher optical band gap. The crystal structures of Cd$_{1-x}$ Zn$_{x}$S films was a wurtzite type with a preferential orientation of the (002) plane and the lattice constants of the films changed from the value for CdS to those for ZnS with increasing the mole ratio of the zinc acetate. The minimum lattice mismatch between Cd$_{1-x}$ Zn$_{x}$S and CdTe were 2.7% at the mole ratio of (ZnAc$_2$)/(CdAc$_2$+ZnAc$_2$)=0.4. As the more zinc substituted for Cd in the films, the optical transmittance improved, while the absorption edge shifted toward a shorterwavelength. the photoconductivity of the films was higher than the dark conductivity, while the ratio of those increased with increasing the mole ratio of zinc acetate. acetate.

• YAKHAK HOEJI
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• v.46 no.4
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• pp.258-264
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• 2002

Zinc plays an important role in immunobiological responses, while excessive zinc attenuates immune functions in a dose-dependent manner. Zinc excess has been reported to increase levels of plasma prostaglandin E$_2$ (PGE$_2$), which is known to inhibit production of Th (helper T) 1-associated cytokines and to induce inflammatory responses. Thus, this study was investigated the effects of indomethacin, a potent inhibitor of PGE$_2$ synthesis, on the proinflammatory cytokine and lymphokine production in ICR mice exposed to excessive zinc. Indomethacin at doses of 5 mg/kg was administered i.p. 30 minutes before zinc chloride (Zn) 30 mg/kg orally daily for 10 days. Excessive Zn remarkedly increased tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-1$\beta$ levels in both serum and splenic supernatants compared with those in controls, while indomethacin significantly reduced the excessive Zn-induced levels of IL-1$\beta$. In serum, excessive Zn significantly decreased the levels of IL-2 and interferon (IFN)-${\gamma}$ compared with those in controls, whereas indomethacin significantly enhanced the excessive Zn-decreased levels of IFN-${\gamma}$ but did not affect the Zn-decreased levels of serum IL-2. In splenic supernatants, All of excessive Zn, indomethacin, and combination of Zn and indomethacin significantly enhanced IL-2 levels compared with those in controls, but indomethacin didn't affect the Zn-induced production of IL-2. These data, therefore, suggest that indomethacin significantly attenuated the in vivo and ex vivo IL-1$\beta$ production increased by excessive zinc and remarkedly enhanced the in vivo excessive zinc-suppressed production of IFN-${\gamma}$ but not IL-2.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.3.1-3.13
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• 2023

Background: Zinc (Zn) is an essential cofactor for physiological homeostasis in the body. Zn oxide (ZnO), an inorganic compound that supplies Zn, exists in various sizes, and its bioavailability may vary depending on the size in vivo. However, comparative studies on the nutritional effects of micro-sized ZnO (M-ZnO) and nano-sized ZnO (N-ZnO) supplementation on Zn deficiency (ZnD) animal models have not been reported. Objectives: This study investigated the nutritional bioavailability of N-ZnO and M-ZnO particles in dietary-induced ZnD mice. Methods: Animals were divided into six experimental groups: normal group, ZnD control group, and four ZnO treatment groups (Nano-Low, Nano-High, Micro-Low, and MicroHigh). After ZnD induction, N-ZnO or M-ZnO was administered orally every day for 4 weeks. Results: ZnD-associated clinical signs almost disappeared 7 days after N-ZnO or M-ZnO administration. Serum Zn concentrations were higher in the Nano-High group than in the ZnD and M-ZnO groups on day 7 of ZnO treatment. In the liver and testis, Nano-Low and Nano-High groups showed significantly higher Zn concentrations than the other groups after 14-day treatment. ZnO supplementation increased Mt-1 mRNA expression in the liver and testis and Mt-2 mRNA expression in the liver. Based on hematoxylin-and-eosin staining results, N-ZnO supplementation alleviated histological damage induced by ZnD in the testis and liver. Conclusions: This study suggested that N-ZnO can be utilized faster than M-ZnO for nutritional restoration at the early stage of ZnD condition and presented Mt-1 as an indicator of Zn status in the serum, liver, and testis.

• Applied Science and Convergence Technology
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• v.23 no.6
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• pp.376-386
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• 2014

Zinc oxysulfide nanocrystals (ZnOS NCs) were synthesized by forming ZnS phase on a ZnO matrix. ZnO nanocrystals (NCs) with a diameter of 10 nm were synthesized by forced hydrolysis in an organic solvent. As-synthesized ZnO NCs aggregated with each other due to the high surface energy. As acetic acid (AA) was added into the milky suspension of the aggregated ZnO NCs, transparent solution of well dispersed ZnO NCs formed. Finally ZnOS NCs were formed by adding thioacetic acid (TAA) to the transparent solution. The effect of recrystallization on the structural, optical and electrical properties of the ZnOS NCs were studied. The results of UV-vis absorption confirmed the band gap tunability caused by increasing the curing temperature of ZnOS thin films. This may have originated from the larger effective size due to the recrystallization of zinc sulfide (ZnS). From XRD result we identified that ZnOS thin films have a zinc blende crystal structure of ZnS without wurtzite ZnO structure. This is probably due to the small amount of ZnO phases. These assertions were verified through EDS of FE-SEM, XPS and EDS mapping of HR-TEM results; we clearly proved that ZnOS were comprised of ZnS and ZnO phases.

• Journal of Nutrition and Health
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• v.32 no.3
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• pp.277-286
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• 1999

This study was conducted to assess dietary intake and nutritional status of zinc and copper in Korean college women. Dietary survey was conducted by 24-hour recall method and fasting serum samples were collected from 111 apparently healthy subjects. Intake levels of zinc and copper were calculated using newly developed database for Zn & Cu of Korea food. Serum levels of Zn, Cu and activities of ALP, EC-SOD were measured from fasting serum sample. Mean daily zinc and copper intakes were 6.72mg/day(56.0% RDA) and 1.11mg/day respectively. Mean values of serum ALP activity, zinc and copper concentration were 43.9U/L, 14.8umol/1, 15.5umol/1and these values were mostly within normal range. EC-SOD activitis of the subjects were low and had no correlation with intake or serum levels of Zn, Cu. In conclusion, these results show that zinc and copper intake of Koran college women are lower than those from other counties but higher than those of adults in rural area of Korea. Their serum levels of Zn, Cu, ALP are relatively normal. These results indicate that marginal deficiency of Zn and Cu may be quite prevalent in these subjects but serum indicators measured may not be sensitive enough to detect such marginal deficiency. Further study in needed to develop a biochemical index sensitive enough to evaluate Zn and Cu status.

• Journal of the Korean Electrochemical Society
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• v.21 no.1
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• pp.12-20
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• 2018

To solve low cycle efficiency of the zinc anode in Zn-air batteries by corrosion, this study examined the effects of Al as a cathodic protection additive to Zn. The Al-mixed Zn anodes were produced by mixing Zn and Al powder (1, 2, and 3 wt. %). To compare the effects of the Al additive, Si was selected under the same conditions. The morphology and elemental composition of the additives in the Zn were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductively coupled plasma - mass spectrometry. The anti-corrosion effects of the Al and Si-mixed Zn anodes were examined by linear polarization. Cyclic voltammetry and charge-discharge tests were conducted to evaluate the electrochemical performance of the Al and Si-mixed Zn anodes. As a result, the Al-mixed Zn anodes showed highest corrosion resistance and cycling performance. Among these, the 2 wt.% Al-mixed Zn anodes exhibited best electrochemical performance.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.47-53
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• 2005

The E.M.F. of the galvanic cell with fused salt was measured to determine the activities of zinc at 720-860 K over the entire composition range of liquid Zn-In and Zn-Sn alloys. The cell used was as follows: $$(-)W{\mid}Zn(pure){\mid}Zn^{2+}(KCl-LiCl){\mid}Zn(in\;Zn-In\;or\;Zn-Sn\;alloy){\mid}W(+)$$ The activities of zinc in the alloys showed positive deviation from Raoult's law over the entire composition range. The activity of cadmium and some thermodynamic functions such as Gibbs free energy, enthalpy and entropy were derived from the results by the thermodynamic relationship. The comparison of the results and the literature data was made. The liquid Zn-In and Zn-Sn alloys are found to be close tn the regular solution. The concentration fluctuations in long wavelength limit, $S_{cc}(o)$, in the liquid alloy were calculated from the experimental results.

• 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.