• 한국전기전자재료학회논문지
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• 제19권7호
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• pp.624-630
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• 2006

ZnO deposition parameters are not independent and have a nonlinear and complex property. To propose a method that could verify and predict the relations of process variables, neural network was used. At first, ZnO thin films were deposited by using RF magnetron sputtering process with various conditions. Si, GaAs, and Glass were used as substrates. The temperature, work pressure, and RF power of the substrate were $50\sim500^{\circ}C$, 15 mTorr, and $180\sim210W$, respectively : the purity of the target was ZnO 4 N. Structural properties of ZnO thin films were estimated by using XRD (0002) peak intensity. The structure of neural network was a form of 4-7-1 that have one hidden layer. In training a network, learning rate and momentum were selected as 0.2, 0.6 respectively. A backpropagation neural network were performed with XRD (0002) peak data. After training a network, the temperature of substrate was evaluated as the most important parameter by sensitivity analysis and response surface. As a result, neural network could capture nonlinear and complex relationships between process parameters and predict structural properties of ZnO thin films with a limited set of experiments.

• 한국진공학회지
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• 제10권1호
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• pp.67-71
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• 2001

MOCVD법으로 성장한 Zn-doped InGaN의 광학적 특성을 photoluminescence를 사용하여 연구하였다. 상온에서 Zn와 관련한 acceptor-like conte들에 대한 넓은 스펙트럼들은 2.81 eV와 2.60 eV에서 관측되었다. 특히, 2.81 eV영역에서는 포논과의 상호작용에 의한 스펙트럼이 나타났으며, 포논 에너지가 $\omega$=92.5 meV의 값을 가짐을 확인하였다. InGaN 시료의 온도 변화에 대한 스펙트럼에서, 온도가 증가함에 따라 청색 발광을 기준으로 낮은 쪽의 에너지에 비해 높은 에너지 쪽의 발광이 빠른 감소를 가져왔으며 아울러 2.81eV 영역에 해당하는 스펙트럼은 18meV만큼 높은 에너지 쪽으로 이동함을 관측하였다. 그러므로 청색 영역에서의 발광은 Zn와 관련된 complex conte체서의 국소화된 천이에 따른 결과이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1280-1283
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• 2005

A novel zinc complex, Zn(phen)q, was synthesized from 1,10-phenanthroline (phen) and 8-hydroxyquinoline (q) as organic ligands and its electroluminescent (EL) properties were characterized. The structure of Zn(phen)q was elucidated by FT-IR, UV-Vis and XPS. The complex Zn(phen)q showed thermal stability up to $300^{\circ}C$ under nitrogen flow, which was measured by TGA and DSC. The photoluminescence (PL) of the Zn(phen)q was measured from the THF solution and the solid film on quartz substrate. The PL emission of Zn(phen)q exhibited green light centered at about 505nm. The EL devices were fabricated by the vacuum deposition. The EL devices having the structure of ITO/a-NPD/Zn(phen)q/Li:Al were studied, where 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(a-NPD) used as a hole transport layer(HTL). a-NPD has high Tg of $96^{\circ}C$ and thus makes the device thermally stable. The EL emission of Zn(phen)q exhibited also green light centered at 532nm.

• E2M - 전기 전자와 첨단 소재
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• 제9권6호
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• pp.572-577
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• 1996

Alternating current and direct current of pure, ball milled, and $Al_{2}$O$_{3}$ added ZnO were investigated by means of complex impedance measurement and voltage-current source measurement unit. The electrical conductivity of A1$_{2}$O$_{3}$ added ZnO samples increases when the content of A1$_{2}$O$_{3}$ is used within 1 at% and decreases when it's used more than that. The increase and decrease of electrical conductivity seem to be the donor effect of $Al_{2}$O$_{3}$ and the increase of the number of ZnO grains, respectively. Impedance spectrum seems to be one semircicle. The size of semicircle increase with increasing the A1$_{2}$O$_{3}$ contents. The calculated dielectric constant(at 50.deg. C) were about 70-140 at the peak of the semicircle. The semicircles seem not to be the resistance of ZnO grain as compared to that of 10 for pure ZnO.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.163-164
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• 2006

ZnO deposition parameters are not independent and have a nonlinear and complex properties respectively. Therefore, finding optimal process conditions are very difficult and need to do many experiments. To predict ZnO deposition result, neural network was used. To gather training data, Si, GaAs, and Glass were used for substrates, and substrate temperature, work pressure, RF power were $50-500^{\circ}C$, 15 mTorr, and 180-210 W respectively, and the purity of target was ZnO 4N. For predicting the result of ZnO deposition process exactly, sensitivity analysis and drawing a response surface was added. The temperature of substrate was evaluated as a most important variable. As a result, neural network could verify the nonlinear and complex relations of variables and find the optimal process condition for good quality ZnO thin films.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1160-1167
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• 2017

Objective: To assess the effects of proteinate complex zinc (PC-Zn) on growth performance, antioxidative function, trace element concentrations and immune function in weaned piglets. Methods: Three hundred newly weaned barrows ($Duroc{\times}Landrace{\times}Yorkshire$), 28 days of age, were randomly allotted to 3 dietary groups of 5 replicate pens per group for 4 weeks of feeding. Experimental diets were: i) zinc deficient diet (ZnD, 24 mg/kg Zn supplementation from $ZnSO_4$), ii) inorganic Zn diet supplemented with 120 mg/kg of Zn from Zn sulfate ($ZnSO_4$), and iii) organic Zn diet supplemented with 120 mg/kg of Zn from PC-Zn. The body weight of pigs were recorded at the beginning, at the middle and at the end of the experiment, and the amount of feed supplied each day was recorded. Five barrows from each dietary treatment group were selected to be anesthetized and euthanized at the end of the trial to determine the Zn, Cu, Fe, and Mn concentrations, the hepatic metallothionein content, the levels of methane dicarboxylic aldehyde (MDA), Mn, and Cu/Zn superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the spleen, the levels of interleukin (IL)-2, IL-4, IL-10, interferon $(IFN)-{\gamma}$, $CD3^+$, $CD4^+$, and $CD8^+$ T lymphocyte. Results: The accumulation of Zn in the spleen, levels of SOD, GSH-Px, IL-4, IL-10, the proportions of $CD3^+$ and $CD4^+$ T lymphocyte, and the ratio of $CD4^+/CD8^+$ T lymphocyte were increased by organic Zn supplementation compared to ZnD, while the levels of MDA, $IFN-{\gamma}$, and proportion of $CD8^+$ T lymphocyte were lowered. Conclusion: These findings indicate that Zn can improve the antioxidant potential and immune functions of weaned piglets.

• 분석과학
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• 제18권5호
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• pp.386-390
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• 2005

The zinc(II) complex, $Zn(NCS)_2(C_3H_4N_2S)_2$, I, has been synthesized and characterized by single crystal X-ray diffraction, thermal analysis and infrared spectroscopy. The complex I crystallizes in the triclinic system, $P\bar{1}$ space group with a = 7.587(1), b = 8.815(1), $c=12.432(2){\AA}$, ${\alpha}=75.584(8)$, ${\beta}=83.533(9)$, ${\gamma}=68.686(8)^{\circ}$, $V=750.0(2){\AA}^3$, Z = 2, $R_1=0.036$ and ${\omega}R_2=0.101$. The central Zn(II) atom has a tetrahedral coordination geometry, with the heterocyclic nitrogen atoms of 2-aminothiazole ligands and the nitrogen atoms of isothiocyanate ligands. The crystal structure is stabilized by one-dimensional networks of the intermolecular $N-H{\cdots}S$ hydrogen bonds between the amino group of 2-aminothiazole ligands and the sulfur atom of isothiocyanate ligands. Based on the results of thermal analysis, the thermal decomposition reaction of complex I was analyzed to have three distinctive stages such as the loss of 2-aminothiazole, the decomposition of isothiocyanate and the formation of metal oxide.

• 한국농공학회논문집
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• 제48권1호
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• pp.3-10
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• 2006

The chemical fractions of heavy metals were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The distribution pattern of each heavy metal in different fractions was in the order: 1) Cu : organic bound > organic complex > residual > exchangeable = water soluble. 2) Cr : residual > organic bound > organic complex > water soluble > exchangeable. 3) Pb : organic bound > residual > organic complex > water soluble > exchangeable. 4) Cd residual > organic bound > organic complex > water soluble = exchangeable. 5) Zn : organic bound > residual > organic complex > water soluble > exchangeable. The content of residual Zn showed positive correlation with organic matter content but organic bound Zn showed negative correlation with CEC. The content of residual and exchangeable Cd showed highly positive correlation with organic matter content but residual, organic bound, and exchangeable Cd showed negative correlations with CEC. Water soluble Pb showed positive correlation with CEC but organic bound Pb showed negative correlation with CEC.

• 한국자기학회지
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• 제5권1호
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• pp.27-33
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• 1995

$Ni_{2-x}Zn_{x}Y$ - 고무 복합체의 ferrite 조성과 입자 크기 변화에 따른 복소투자율과 전파흡수 특성을 조사하였다. Ferrite 입자가 $1\mu\textrm{m}$ 이하인 경우에는 ferrite-고무 복합체가 단자구 거동을 하여 자연공명 현상만이 관찰되었다. $Ni_{2-x}Zn_{x}Y$ - 고무 복합체의 제 1정합주파수는 Zn 함량이 증가함에 따라서 저주파 대역으로 이동하였으며, 자연공명 주파수와 비례함을 알 수 있었다. 반면에 제 2정합주파수는 자연공명 주파수에 비례하지 않음을 확인하였다. 또한 복합 ferrite 전파흡 수체의 전파흡수 현상은 자벽공명보다는 자연공명에 크게 영향을 받음을 확인하였다.

• 한국세라믹학회지
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• 제32권1호
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• pp.25-30
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• 1995

The frequenc dependence of magnetic permeability($\mu$r) and dielectric constant($\varepsilon$r) in MHz-GHz frequency range and their relationships with microwave absorbing properties were investigated in sintered and composite Ni-Zn ferrites, respectively. It was confirmed that zero reflection condition was required the real parts of permeability and permittivity in sintered specimen, and the complex permeability, permittivity and dielectric loss tangent in composite specimen. The real part of permittivity varied with the replacement of nickel by manganese in sintered Ni-Zn ferrite. Therefore, we could control the matching frequency and matching thickness.