• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1809-1814
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• 2006

The L-Valinate anion coordinating zinc complex, [$Zn(val)_2(H-2O)$], was isolated and structurally characterized by single crystal X-ray crystallography. The crystal possess orthorhombic symmetry with a space group $P2_12_12_1$, Z = 4, and a = 7.4279(2)$\AA$, b = 9.4342(2)$\AA$, c =20.5862(7)$\AA$ respectively. The compound features a penta-coordinate zinc ion in which the two valine anion molecules are directly coordinating the central zinc metal ion via their N (amine) and O (carboxylate) atoms, and an additional coordination to zinc is made by water molecule (solvent) to form a distorted square pyramidal structure. In addition, further synthesis of the valine capped ZnS:Mn nanocrystal from the reaction of [$Zn(val)_2(H-2O)$] precursor with $Na_2S$ and 1.95 weight % of $Mn^{2+}$ dopant is described. Obtained valine capped nanocrystal was water dispersible and was optically characterized by UV-vis and solution PL spectroscopy. The solution PL spectrum for the valine capped ZnS:Mn nanocrystal showed an excitation peak at 280 nm and a very narrow emission peak at 558 nm respectively. The measured and calculated PL efficiency of the nanocrystal in water was 15.8%. The obtained powders were characterized by XRD, HR-TEM, and EDXS analyses. The particle size of the nanocrystal was also measured via a TEM image. The measured average particle size was 3.3 nm.

• 한국습지학회지
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• 제12권1호
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• pp.23-31
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• 2010

본 연구는 고농도의 PCE 및 1,1,1-TCA가 단독 또는 혼합물로 오염된 지하수 복원을 위해 영가 금속을 이용한 탈염소환원공정을 적용할 때 기술적으로, 경제적으로 가장 적절한 영가금속 선정을 목표로 수행되었다. 고순도 영가철, 고순도 영가아연, 철광석, 고로 슬래그, 차수재용슬래그, 망간 광석 및 아연 광석 등을 대상으로 회분식 반응조 실험을 수행하였으며, PCE, 1,1,1-TCA 및 혼합물의 분해능 및 탈염소화율을 도출하고, 금속 단가 당 변환량을 포함한 경제성 등을 검토하여 최적의 금속광물을 선정하고자 하였다. 연구결과 단일물질 처리시 고순도 영가철과 고순도 영가아연에 의한 제거율 및 분해능이 가장 높게 나타났으며, 그 다음으로 아연광석에 의한 분해능이 양호하였다. 두 물질 제거를 위한 경제성 비교에서는 고순도 영가철과 고순도 영가아연에 비해 아연광석이 매우 양호한 것으로 나타났다. 두 물질의 혼합처리 시에는 단일 처리에 비해 분해능이 감소하는 것으로 나타났다. 이상의 결과로부터 단일 또는 혼합 1,1,1-TCA, PCE 처리를 위한 분해능, 처리특성 및 경제성 등을 고려하였을 때 아연광석이 가장 적절한 금속광물로 사료된다.

• 한국어병학회지
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• 제35권1호
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• pp.77-92
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• 2022

Aquaculture development is based on the ideas of increasing production while reducing economic losses. Bacterial diseases are the leading source of fish cases. Citrobacter freundii has been linked to septicemia and mortality all over the world. In the current study, the cause of mortality in O. niloticus was C. freundii MW279218. External hemorrhages were seen on the affected fish, as well as paleness in the liver and kidney congestion. C. freundii MW279218 had a median lethal dosage of 1.5×10⁵ CFU/mL. Zinc oxide and zinc oxide nanoparticles (ZnO-NPs) were tested for their biocidal effectiveness against C. freundii MW279218. The lethal effect of ZnO-NPs for C. freundii MW279218 was 100% when compared to zinc oxide compound, and the inhibition zone width was 2.31.1mm at the highest tested concentrations (70 mg/L) compared to the lowest (35 and 45 mg/L, respectively). Fish were fed three different diets for 28 days: diet 1 (no additives), diet 2 (100 mg of ZnO-NPs/kg of feed), and diet 3 (200 mg of ZnO-NPs/kg of feed). Organs were also collected for histopathology 96 hours after injection (P<0.05). In the groups given 200 mg of ZnO-NPs, there was 10% mortality and 80% RPS. The group fed 100 mg of ZnO-NPs/kg, on the other hand, had 20% mortality and 60% RPS, compared to 50% mortality in the control positive group. Histopathological examinations demonstrated significant alterations in the control positive group and mild lesions in the hepatopancreas of the groups administered 100 mg ZnO-NPs/kg of feed. The groups fed 200 mg of ZnO-NPs/kg diet, on the other hand, showed no histological alterations. ZnO-NPs were found to be effective in the up regulation of both IL-10 and complement 5 immune-related genes.

• Journal of Veterinary Science
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• 제24권1호
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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.

• 한국표면공학회지
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• 제46권3호
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• pp.116-119
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• 2013

To improve the corrosion resistance of an electrogalvanized steel sheet, we deposited magnesium film on it using a vacuum evaporation method and annealed the films at $250-330^{\circ}C$. The zinc-magnesium alloy is consequently formed by diffusion of magnesium into the zinc coating. From the anodic polarization test in 3% NaCl solution, the films annealed at $270-310^{\circ}C$ showed better corrosion resistance than others. In X-ray diffraction analysis, $ZnMg_2$ was detected through out the temperature range, whereas $Mg_2Zn_{11}$ and $FeZn_{13}$ were detected only in the film annealed at $310^{\circ}C$. The depth composition profile showed that the compositions of Mg at $270-290^{\circ}C$ are evenly and deeply distributed in the film surface layer. These results demonstrate that $270-290^{\circ}C$ is a proper temperature range to produce a layer of $MgZn_2$ intermetallic compound to act as a homogeneous passive layer.

• Journal of Information Display
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• 제11권4호
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• pp.165-168
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• 2010

A solution-processed multicomponent oxide, yttrium hafnium zinc oxide (YHZO), was synthesized and deposited as a gate insulator. The YHZO film annealed at $600^{\circ}C$ contained an amorphous phase based on the results of thermogravimetry, differential thermal analysis, and X-ray diffraction. The electrical characteristics of the YHZO film were analyzed by measuring the leakage current. The high dielectric constant (16.4) and high breakdown voltage (71.6 V) of the YHZO films resulted from the characteristics of $HfO_2$ and $Y_2O_3$, respectively. To examine if YHZO can be applied to thin-film transistors (TFTs), indium gallium zinc oxide TFTs with a YHZO gate insulator were also fabricated. The desirable characteristics of the YHZO films when used as a gate insulator show that the limitations of the general binary-oxide-based materials and of the conventional vacuum processes can be overcome.

• Journal of Welding and Joining
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• 제33권1호
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• pp.49-53
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• 2015

An experimental study was conducted to investigate the effect of carbon nanotubes on the zinc corrosion resistance of sealing layer formed on the Tungsten Carbide spray coating. Using the nanotubes, a sealing agent in the form of solid-liquid suspensions was made and applied to the surface of spray coating. A series of experiments, consisted of three stages such as preparation of test piece, molten-pot immersion test, and evaluation of micro structure, were undertaken to demonstrate complicated interaction existing between zinc ions and sealing layer containing the nanotubes. Experimental results showed newly developed sealing layer were less susceptible to corrosion and thus coated layer was well protected even in the case of 10 days exposure. Comparison of the micro structure after molten pot test also indicated that carbon nanotubes still remained in the matrix and organized more reliable frame work constituted with boron nitride and chromium compound. It was revealed that carbon nanotubes in the sealing layer played positive role to enhance zinc corrosion resistance in the perspective of both fibrous structure and inherent chemical stability.

• Journal of Information Display
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• 제10권4호
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• pp.171-174
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• 2009

The optical and electrical properties of the amorphous indium gallium zinc oxide thin-film transistor ($\alpha$-IGZO TFT) were studied. When the $\alpha$-IGZO TFT was illuminated at a wavelength of 660 nm, the off-state drain current slightly increased, while below 550 nm it increased significantly. The $\alpha$-IGZO TFT was found to be extremely sensitive, with deep-level defects at approximately 2.25 eV near the midgap. After UV light illumination, a slight change occurred on the surface of the $\alpha$-IGZO films, such as in terms of the oxygen 1s spectra, resistivity, and carrier concentrations. It is believed that these results will provide information regarding the photo-induced behaviors in the $\alpha$-IGZO films.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.531-533
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• 2009

We've studied the optical and electrical properties of amorphous indium gallium zinc oxide thin-film transistor (a-IGZO TFT). When the a-IGZO TFT was illuminated at a wavelength of 660 nm, the offstate drain current was slightly increased, while below 550 nm it was increased significantly. The a-IGZO TFT was extremely sensitive, with deep-level defects at approximately 2.25 eV near the midgap.

• Macromolecular Research
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• 제10권6호
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• pp.369-372
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• 2002

The use of ZnO and stearic acid is very well known in sulfenamide accelerated sulfur vulcanization of diene elastomers. Zn-ion coated nano filler has been developed and tested, in styrene-butadiene rubber (SBR) as sulfur vulcanizing activator cum reinforcing filler. In this study Zinc oxide has been replaced by the Zn-ion coated nano silica filler with an aim to study the dual role of this nanofiller in SBR. The presence of Zn-ion on the nano silica filler surface activates the sulfur vulcanization by involving Zn++ in to the sulfurating complex formed with thiazole from sulfenamide. The increase of Zn-ion, on the nanofiller, decrease the scorch safety of the elastomer compound but increase the tensile strength, state of cure and tear strength and attain maximum at its 10% level. The presence of stearic acid increases the rate of vulcanization. Replacement of stearic acid with mono-stearate, however, increases the vulcanization rate but decrease the ultimate state of cure. A mechanistic scheme involving dual function of this nanofiller has been suggested.