• 대한화학회지
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• 제31권5호
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• pp.444-451
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• 1987

에틸렌디아민, 프로필렌디아민 및 디에틸렌트리아민의 구리(II), 카드뮴(II) 및 아연(II)착이온의 桓元에 대하여 압력에 따른 폴라로그래피적 파라미터의 依存性을 조사하였다. 水銀滴下電極, 고인수은전극 및 나선형 백금선을 각각 作業電極, 基準電極 및 補助電極으로 사용하였다. 압력이 1기압에서 1,500기압으로 증가함에 따라 금속착이온의 還元半波電位는 陰電位 쪽으로 이동하였으며, 擴散電流는 상당히 커졌다. 이러한 현상은 전해질용액의 물리적 성질 곧 密度, 粘性度, 誘電常數, 電氣傳導度 등이 압력이 증가함에 따라 커지기 때문이다. 압력을 증가시키면 log plot의 기울기 값이 커지므로 환원반응의 可逆性은 나빠지고 있다. 25$^{\circ}$C ~ 35$^{\circ}$C의 온도범위에서 측정한 확산전류의 溫度係數가 압력을 증가시켜도 2%정도이므로 高壓下에서 폴라로그래피적 환원반응은 擴散支配的이다. 또 실험압력 범위내에서 금속착이온의 확산전류와 농도 사이에는 線形關係가 성립하였다.

• Carbon letters
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• 제10권2호
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• 한국환경과학회지
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• 제21권8호
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• pp.891-899
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• 2012

The chlorination pattern of naphthalene vapor when passed through a 1 cm particle bed of 0.5% (mass) copper (II) chloride ($CuCl_2$) mixed with silicon dioxide ($SiO_2$) was studied. Gas streams consisting of 92% (molar) $N_2$, 8% $O_2$ and 0.1% naphthalene vapor were introduced to an isothermal flow reactor containing the $CuCl_2/SiO_2$ particle bed. Chlorination of naphthalene was studied from 100 to $400^{\circ}C$ at a gas velocity of 2.7 cm/s. Mono through hexachlorinated naphthalene congeners were observed at $250^{\circ}C$ whereas a broader distribution of polychlorinated naphthalenes (PCNs) including hepta and octachlorinated naphthalenes was observed at $300^{\circ}C$. PCN production was peak at $250^{\circ}C$ with 3.07% (molar) yield, and monochloronaphthalene (MCN) congeners were the major products at two different temperatures. In order to assess the effect of a residence time on naphthalene chlorination, an experiment was also conducted at $300^{\circ}C$ with a gas velocity of 0.32 cm/s. The degree of naphthalene chlorination increased as a gas velocity decreased.

• 전기전자학회논문지
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• 제22권1호
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• pp.1-5
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• 2018

Sol-gel 공법을 이용하여, p-형 CuO 박막 트랜지스터를 제작하였다. 제작된 CuO 박막 트랜지스터는 copper (II) acetate monohydrate 를 전구체로 사용하였다. $500^{\circ}C$ 열처리 후에 형성된 전구체는 p-형 CuO 박막이 됨을 확인하였다. 또한 전구체를 형성하기 전 기판표면의 $UV/O_3$ 조사량에 따른 CuO 박막 트랜지스터의 전기적 특성변화에 대하여 연구하였으며, 600 초동안 $UV/O_3$를 조사한 경우 제작된 CuO 박막 트랜지스터는 $5{\times}10^{-3}\;cm^2/V{\cdot}s$ 의 이동도와 약 $10^2$의 온/오프 전류비를 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1781-1786
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• 2007

Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

• KSBB Journal
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• 제27권4호
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• pp.257-262
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• 2012

The gene encoding Thermus thermophilus HJ6 laccase (Tt-laccase) was cloned, sequenced, and comprised of 1,389 nucleotides encoding a protein (462 amino acids) with a predicted molecular mass of 51,049 Da. The deduced amino acid sequence of Tt-laccase showed 99.7% and 44.3% identities to the Thermus thermophilus HB27 laccase and Synechococcus sp. RS9917 laccase, respectively. Tt-laccase gene was expressed as a fusion protein with six histidine residues in E. coli Rosetta-gami (DE3) cells, and the recombinant protein was purified to homogeneity. UV-Vis spectrum analysis revealed that the enzyme has copper atoms, a type I Cu(II) and a type III binuclear Cu(II). The optimum pH for the oxidation of guaiacol was 5.0 and the optimum temperature was $90^{\circ}C$ The half-life of heat inactivation was about 120 min at $90^{\circ}C$ The enzyme reaction was inhibited by sodium azide, L-cystein, EDTA, dithiothreitol, tropolone, and kojic acid. The enzyme oxidized various known laccase substrates, its lowest $K_m$ value being for 4-hydroxyindole, highest $k_{cat}$ value for syringaldazine, and highest $k_{cat}/K_m$ for guaiacol.

• 전기화학회지
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• 제4권2호
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• pp.41-46
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• 2001

황산과 황산구리 수용액을 전해질로 사용하여 다공성 그물구조 금속을 전기화학적으로 제조하였으며, 이때 균질 전착에 영향을 미치는 첨가제 PEG, MPS의 영향에 대해 살펴보았다. 분극실험과 기공의 평균 직경이 $250{\mu}m$의 그물구조 전극을 여러장 적층하여 throwing power를 정량화 한 결과, PEG의 경우 분극 초기에 전극에서 탈착됨으로써 오히려 throwing power를 감소시키고 MPS는 500ppm까지 용액 중 첨가량의 증가와 함께 throwing power를 향상시키는 결과를 보였다 또한 MPS와 PEG가 동시에 혼합된 용액에서는 MPS의 효과가 우선적으로 나타나며 PEG의 효과는 무시할 정도였다 그러나 MPS의 첨가는 전착층의 균열을 유도하여 기계적 강도에 좋지 못한 영향을 미치며 균열을 피하려면 50ppm 이하가 적정함을 SEM 관찰을 통해 확인할 수 있었다.

• Membrane and Water Treatment
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• 제1권3호
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• pp.171-179
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• 2010

The transport of selected salts of sulphuric acid (cobalt, copper, iron(II), manganese, nickel and zinc sulphate) through an anion-exchange membrane Neosepta-AFN was investigated in a counter-current continuous dialyzer at various salt concentrations and volumetric liquid flow rates. The basic transport characteristics - the rejection coefficient of salt and the permeability of the membrane - were calculated from measurements at steady state. The salt concentration in model mixtures was changed in the limits from 0.1 to 1.0 kmol $m^{-3}$ and the volumetric liquid flow rate of the inlet streams was in the limits from $8{\times}10^{-9}$ to $24{\times}10^{-9}m^3\;s^{-1}$. Under the experimental conditions given, the rejection coefficient of salts tested was in the range from 65% to 94%. The lowest values were obtained for iron(II) sulphate, while the highest for copper sulphate. The maximum rejection of salt was reached at the highest volumetric liquid flow rate and the highest salt concentration in the feed. The permeability ($P_A$) of the Neosepta-AFN membrane for the individual salts was in the range from $0.49{\times}10^{-7}m\;s^{-1}$ to $1.8{\times}10^{-7}m\;s^{-1}$ and it can be described by the following series: $P_{FeSO_4}$ < $P_{NiSO_4}$ < $P_{ZnSO_4}$ < $P_{CoSO_4}$ < $P_{MnSO_4}$ < $P_{CuSO_4}$. The permeability of the membrane was strongly affected by the salt concentration in the feed - it decreased with an increasing salt concentration.

• 공업화학
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• 제10권6호
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• pp.902-906
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• 1999

메틸셀루로스를 호스트고분자로 하고 copper(II) percolate를 산화제로 사용하여 기상상태에서 직접중합방법으로 전도성 복합필름을 합성하였다. 필름으로서 우수한 성형성과 기계강도를 갖고 있는 메틸셀루로즈는 PVA와 키토산과는 달리 피롤에 대하여 높은 친화성을 나타내어서 기상중합시 호스트고분자로 적합하였다. 기상중합법으로 합성된 폴리피롤은 복합재료 내에서 전도성네트워크를 형성하여 전도성 복합필름의 전기전도도는 $10^{-1}-10^{-7}S/cm$를 나타내었다. 피롤이 호스트고분자 내에서의 폴리피롤로 중합이 되는 정도를 UV-vis분광계로 확인하였다. 전도성 복합필름의 전기전도도와 기계강도는 산화제의 농도와 합성시간에 크게 의존하였다. TGA분석결과는 호스트고분자 내에 형성된 폴리피롤은 복합재료의 열적 안정성에 영향을 미치지 않는다. 전자현미경 분석결과 폴리피롤이 복합재료 내에 균일하게 침투하여 분산되어 있음을 나타내었다. DMA를 사용하여 폴리피롤과 호스트고분자와의 상용성을 조사하였으며 dynamic mechanical analysis(DMA) 분석결과 복합재료 내에서 폴리피롤의 함량이 증가되면서 상용성이 점진적으로 저하되었다.

• 대한수의학회지
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• 제33권3호
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• pp.493-505
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• 1993

Present experiments were undertaken in order to clarify the clinico-pathological characteristics of lead poisoning in goats. Twenty goats were divided into three experimental groups(A, B and C) and a control(D). The three experimental groups received diets contaminated artificially with 10(A group), 200(B group) and $1,000(C group){\mu}g/g$ of lead for 70 days, respectively. The control group received normal diets. Hair samples collected one or two weeks interval were examed for the lead content. On day 70. all the animals were necropsied and various organs were examined pathoanatomically. In addition, various organs were analyzed for lead, zine, copper, iron and calcium content by atomic absorption spectrophotometry. From these experiments following results were obtained ; The lead content of hair was significantly increased from the $42^{nd}$, $21^{st}$ or $14^{th}$ day in all the three groups, which showed significant correlation with lead content of liver and spleen. The lead content of various organs including kidney, liver, spleen, ileum, bone and abomasum were significantly increased in accordance with the lead contamination. The increase was most prominent in abomasal wall. The zinc and copper content of liver, brain, ileum, skin, kidney, lung or muscle were increased in B and C groups whereas the iron and calcium content showed no significant change. Pathoanatomically, degeneration or necrosis of proximal convoluted tubules of kidney, peripheral necrosis of liver, fundic gland necrosis of abomasum and cerebral edema were observed in B and C groups.