• 한국재료학회지
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• 제24권1호
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• pp.43-47
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• 2014

NiO-doped hibonite pigments were synthesized by the solid state method to get stabilized blue color pigment in both oxidation and reduction atmospheres. Optimum substitution condition with NiO for hibonite blue pigment was investigated. Experimental results were comparable to those of previous cobalt-minimization studies performed with other phosphate- or oxide-based cobalt-containing ceramic pigments (having olivine ($Co_2SiO_4$), spinel ($CoAl_2O_4$), or with co-doped willemite ($(Co,Zn)_2SiO_4$) structures). Composition was designed varying the NiO molar ratio increasing with $SnO_2$. The optimum substitution content is 0.93 mole NiO with 0.75mole $SnO_2$. The characteristics of the synthesized pigment were analyzed by XRD, Raman spectroscopy, SEM, and UV-vis. Synthesized pigment was applied to a lime-barium glaze with 10 wt% each and fired at an oxidation atmosphere of $1250^{\circ}C/1h$ and a reducing atmosphere $1240^{\circ}C/1h$. Blue color was obtained with $L^*a^*b^*$ values at 43.39, -6.78, -18.20 under a reducing atmosphere and 41.66, -6.36, -14.7 under and oxidation atmosphere, respectively.

• Environmental Engineering Research
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• 제23권1호
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• pp.1-9
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• 2018

The degradation of methylene blue (MB) in an aqueous solution by nano-metallic particles (NMPs) was studied to evaluate the possibility of applying NMPs to remove MB from the wastewater. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized NMPs before and after the reaction. The effects of the NMP dosage, the initial pH, the initial concentration of MB and the amount of $H_2O_2$ on the MB degradation outcomes were studied. The highest removal rate of MB was achieved to be 100% with an initial MB concentration of 5 mg/L, followed by 99.6% with an initial concentration of 10 mg/L under the following treatment conditions: dose of NMP of 0.15 g/L, concentration of $H_2O_2-100mM$ and a temperature of $25^{\circ}C$. The SEM analysis revealed that the nano particles were not spherical in shape. FTIR spectra shows occurrence of metal oxides on the surfaces of the NMPs. The XPS analyses results represent that Fe, Zn, N, Ca, C and O were occurred on the surfaces of the NMPs. The degradation of MB was suitable for the pseudo-first-order kinetics.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2125-2130
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• 2013

A new nickel(II) complex $[NiL^1]^{2+}$ ($L^1$ = 1-(2-aminoethyl)-3-(N-{2-aminoethyl}aminomethyl-1,3-diazacyclohexane) containing one 1,3-diazacyclohexane ring has been prepared selectively by the metal-template condensation of formaldehyde with N-(2-aminoethyl)-1,3-propanediamine and ethylenediamine at room temperature. The complex reacts with nitroethane and formaldehyde to yield the pentaaza macrocyclic complex $[NiL^2]^{2+}$ ($L^2$ = 8-methyl-8-nitro-1,3,6,10,13-pentaazabicyclo[13.3.1]heptadecane) bearing one C-$NO_2$ pendant arm. The reduction of $[NiL^2]^{2+}$ by using Zn/HCl produces $[NiL^3(H_2O)]^{2+}$ ($L^3$ = 8-amino-8-methyl-1,3,6,10,13-pentaazabicyclo[13.3.1]heptadecane) bearing one coordinated C-$NH_2$ pendant arm that is readily protonated in acid solutions. The hexaaza macrocyclic complex $[NiL^4]^{2+}$ ($L^4$ = 8-phenylmethyl-8-nitro-1,3,6,8,10,13-hexaazabicyclo[13.3.1]heptadecane) bearing one N-$CH_2C_6H_5$ pendant arm has also been prepared by the reaction of $[NiL^1]^{2+}$ with benzylamine and formaldehyde. The nickel(II) complexes of $L^1$, $L^2$, and $L^4$ have square-planar coordination geometry in the solid states and in nitromethane. However, they exist as equilibrium mixtures of the square-planar $[NiL]^{2+}$ (L = $L^1$, $L^2$, or $L^4$) and octahedral $[NiL(S)_2]^{2+}$ species in various coordinating solvents (S); the proportion of the octahedral species $[NiL(S)_2]^{2+}$ is strongly influenced by the ligand structure and the nature of the solvent. Synthesis, spectra, and chemical properties of the nickel(II) complexes of $L^1-L^4$ are described.

• 한국전기전자재료학회논문지
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• 제19권12호
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• pp.1085-1091
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• 2006

The microstructure, electrical properties, and its stability of (Pr, Co, Cr, La)-doped ZnO varistors were investigated at different sintering temperatures in the range of $1230{\sim}1300^{\circ}C$. As the sintering temperature increased, the sintered density increased from 5.50 to $5.77g/cm^3$, the varistor voltage decreased from 777.9 to 108.0 V/mm, the nonlinear coefficient decreased from 77.0 to 7.1, and the leakage current increased from $0.4{\mu}A\;to\;50.6{\mu}A$. On the other hand, the donor concentration increased from $0.90{\times}10^{18}\;to\;2.59{\times}10^{18}/cm^3$ and the barrier height decreased from 1.89 to 0.69 eV with increasing temperature. The stability of nonlinear electrical properties was obtained from sintering temperature of $1260^{\circ}C$. The varistors sintered at $1260^{\circ}C$ marked the high electrical stability, with $%{\Delta}V_{1mA}=+1.9%,\;%{\Delta}a=10.6%,\;and\;%{\Delta}I_L=+20%$ for DC accelerated aging stress state of $0.95V_{1mA}/150^{\circ}C/24h$.

• 동아시아식생활학회지
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• 제10권6호
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• pp.507-513
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• 2000

This study was conducted to investigate the shelf life of beef stored in antimicrobial pottery during 12days storage at 4'C and Five kinds of antimicrobial potteries were prepared with antimicrobial materials such as TiO$_2$, Ag (NO$_3$)$_2$, Cu(NO$_3$)$_2$ and Zn(NO$_3$)$_2$. In changes of color during storage, Hunter's L- and b-value of beef were not changed, but Hunter's a-value was low significantly. The pH of beef meats were low at 6 days, but were added from 6 days. TBA value of beef in "A" pottery containing TiO$_2$ 1% and "C" Pottery containing TiO$_2$ 0.5%, Cu(NO$_3$)$_2$ were lower than "B", "D" and "I" pottery. VBN contents of beef in "A", "B", "C", "D" and "I" Pottery stored during 12 days were 9.8, 12.5, 9.3, 11.9 and 13.7mg%, respectively. In changes of total plate count of beef during storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.g storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.ttery were superior.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.355-356
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• 2008

In this work, ZnO films doped with different contents of Indium (0.1at.%, 0.3at.%, 0.6at.%, respectively) were deposited on Si (111) substrate that has 1~20 $\Omega$cm by pulsed laser deposition (PLD) at $600^{\circ}C$ for 30min. The thickness of the films are about 250 nm. The structural, optical and electrical properties of the films were investigated using X-ray Diffraction (XRD), Atomic force microscope (AFM), Photoluminescence (PL) and Hall measurement. It has been found that RMS of the films is decreased and grain size is increased with increasing the contents of doped Indium. The results of the Photoluminescence properties were indicated that the films have UV emission about 380nm and shows a little red shitf with increasing contents of doped indium. The result of the Hall measurement shows that the concentration and resisitivity in doped ZnO are as changing as one order, respectively ${\sim}10^{18}/cm^2$, ${\sim}10^{-2}cm{\Omega}cm$.

• 대한한의학회지
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• 제23권4호
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• pp.140-150
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• 2002

Objectives: The water extract of Omija-tang (OMIT) has traditionally been used for treatment of ischemic heart and brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of OMJT rescues cells from these damages. Therefore, this study was designed to investigate the protective mechanisms of OMJT on oxidative stress-induced toxicity in H9c2 cardiomyoblast cells. Methods: Treatments of $H_2O_2$, or $ZnC_{12}$ markedly induced death of H9c2 cardiomyoblast cells in a dose-dependent manner. The characteristics of oxidative stress-induced death of H9c2 showed apparent apoptotic features such as DNA fragmentation. OMJT significantly reduced both ${H_2O_2}-induced$ cell death and chromatin fragmentation. The decrease of B치-XL expression by $H_2O_2$ were inhibited by OMJT. In addition, the increase of Bcl-XS expression was also inhibited by OMJT. In particular, Fas expression, which is generally recognized as cell death-inducing signal by Fas/FasL interaction, was markedly increased by H2O2 in a time-dependent manner. Also, the expression profile of proteins in Chang cells were screened by using two-dimensional (2-D) gel electrophoresis. Among 300 spots resolved in 2-D gels; the comparison of control versus apoptotis cells revealed that signal intensity of 6 spots decreased and 11 spots increased. Results and Conclusions: Taken together, this study suggests that the protective effects of the water extract of OMJT against oxidative damages may be mediated by the modulation of Bcl-XL/S Fas expression.

• 한국환경농학회지
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• 제13권3호
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• pp.321-337
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• 1994

주택용 소형 퇴비화용기에 의한 부엌쓰레기의 퇴비화 가능성을 검토하기 위하여 두가지 용기(Type 1과 Type 2)를 제작하여 실험실 실험을 통하여 조사하였다. 두 용기의 구조는 같으나 차이점은 Type 1은 보온을 하였고 Type 2는 보온을 하지 않았다. 겨울철 실험을 통하여 Type 2는 우리나라의 기후 여건에 사용이 불가능한 것으로 판단되어 봄철 및 여름철 실험에서 제외하였다. 따라서 Type 1에 대한 계절 실험결과를 요약하면 다음과 같다. 1) 퇴비화기간 중 상승한 최고온도는 봄철 $58^{\circ}C$, 여름철 $57^{\circ}C$, 겨울철 $41^{\circ}C$였다. 따라서 우리나라의 기후조건에서는 반드시 보온이 필요하다는 것이 확인되었다. 2) 퇴비화원료물질의 무게는 8주 후 평균 62.5% 그리고 부피는 평균 74% 감소하였다. 3) 퇴비충의 밀도는 봄철 0.7kg/l, 여름철 0.8kg/l, 겨울철 1.1kg/l였다. 4) 수분함량은 전 퇴비화기간동안 큰 변동이 없었으며 8주 후 봄철 75.6%, 여름철 76.6%, 겨울철 76.6%였다. 5) pH는 계절에 따라 큰 차이를 보였으며 여름철에 가장 높았고, 겨울철에 가장 낮았다. 8주 후 봄철 6.13, 여름철 8.62, 겨울철 4.75였다. 6) 퇴비화시간의 경과에 따른 회분 및 유기물 함량은 유기물 분해속도가 빠를수록 증감현상이 뚜렷하였고 cellulose 및 lignin은 증가, hemicellulose 함량은 감소하였다. 7) 질소함량은 3.1-5.6%로 높았으며, 특히 여름철에 가장 높았다. 암모늄태 질소는 전반기에 증가했다가 감소하는 경향이었으며 겨울철 2주째 3,243mg/kg, 봄철 3주째 6,052mg/kg, 여름철 6주째 30,828mg/kg으로 가장 높았다. C/N율은 퇴비화시간이 경과함에 따라 감소하였으나 차이는 크지 않았다. 그러나 질산화는 봄 및 여름철에만 일어나고 겨울철에는 거의 일어나지 않았다. 8) 휘발성 및 고급유기산함량은 초기에 증가했다가 계절적으로 시기적 차이는 있으나 감소하였다. 총 유기산의 최고농도는 겨울철 2주째 10.1%, 봄철 2주째 5.8%, 여름철 4주째 15.7%였다. 9) 퇴비의 부숙도와 무관하게 각 무기성분함량은 $P_2O_5$ 0.9-4.4%, $K_2O$ 1.6-2.9%, CaO 2.4-4.6%, MgO 0.30-0.80%였다. 10) CN 및 각종 중금속함량도 퇴비화시간에 따라 큰 변화가 없었으며 각 함량범위는 계절 구분없이 CN 0.11-28.89mg/kg, Zn 24-l30mg/kg, Cu 5-219mg/kg, Cd 0.8-14.3mg/kg, Pb 7-42mg/kg, Cr ND-30mg/kg, Hg $ND-132.16\;{\mu}g/kg$이었다.

• 대한화학회지
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• 제55권6호
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• pp.926-931
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• 2011

A series of complexes of the type [$ML_2Cl_2$], where L=2-(o-anisylidene-2'-imino) amino benzimidazole (AIAB) and 2-(furfurylidene imino) amino benzimidazole (FIAB), M=Cu(II), Co(II), Ni(II) and Zn(II), have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductivity, magnetic moment, electronic, infrared, $^1H$-NMR spectral studies. The results are in consistent with bidentate chelation of ligand with azomethine nitrogen and ring nitrogen donors. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis, Bacillus stearothermophilus, Escherichia coli and Salmonella typhi) and antifungal activities (Aspergillus niger and Aspergillus flavus).

• 한국미생물·생명공학회지
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• 제8권3호
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• pp.181-191
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• 1980

전보에서 분리선정된 균의 발효조건 및 각종첨가물의 영향을 검토하고 배양물을 분석한 결과는 다음과 같다. 1. 선정균의 최적배양 조건은 표면배양의 경우, M-80은 sucrose 140g, (N $H_4$)$_2$S $O_4$3.0g, K $H_2$P $O_4$1.5g, MgS $O_4$.7$H_2O$ 0.25g, F $e^{++}$ 3.0mg, $Zn^{++}$ l.0mg, D. W. 1ι, pH 5.0 이었고, M-315는 sucrose 140g, N $H_4$N $O_3$2.0g, K $H_2$P $O_4$1.0g, MgS $O_4$. 7$H_2O$ 0.25g, F $e^{++}$ 2.0mg, $Zn^{++}$ 2.0mg, C $u^{++}$ 0.05mg, D. W. 1ι pH 4.5 이였으며, M-315의 액내배양의 경우 sucrose 140g, N $H_4$N $O_3$2.5g, K $H_2$P $O_4$1.5g, MgS $O_4$.7$H_2O$ 0.3g, F $e^{++}$ 3.0mg, $Zn^{++}$ 3.0mg, C $u^{++}$ 0.1mg, D. W. 1ι, pH 4.5이었다. 배양온도는 28~3$0^{\circ}C$, 포자접종량은 배양액에 $10^{7}$ -$10^{8}$ 개/ml 접종하였을 때 산생성이 가장 좋았다. 2. 선정균의 생육상태와 산생성관계를 경시적으로 조사한 결과 배양 3~4일 후에 균체의 증식은 거의 끝나고 pH는 2.0이하로 저하되었으며 구연산은 이때부터 급속히 축적되기 시작하여 표면배양의 경우, M-80은 8일, M-315는 9일, M-315의 액내배양의 경우는 10일간 배양하였을 때 구연산생성량이 최고치에 달하였다. 3. Methanol의 첨가는 구연산생성에 좋은 영향을 미쳤으며 표면배양의 경우 M-80, M-315의 배양액에 2.0%, 3.0% 첨가하였을 때 카곽 6.5%, 20%의 수율이 향상되었고, M-315의 액내배양액에는 3.0%의 첨가로 5.0% 의 수율이 향상되었다. 4. 최적조건하에서 발효시킨 분리균의 배양물을 분석한 결과 대부분이 구연산만을 선택적으로 축적하고 있었고, 표면배양의 경우 M-80, M-315 배양액에 각각 72.1mg/ml, 98.1mg/ml이, M-315의 액내배양액에는 59.8mg/ml 구연산이 정량되었다.