• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 1부
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• pp.144-146
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• 2011

Al-MCM-48 molecular sieves (Si/Al = 25, 50, 75 and 100) were synthesized hydrothermally using cetyltrimethyl ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and TEM images. The catalytic performance was evaluated in the vapour phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol (selectivity: 78%). Delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Though ester was used as the alkylating agent, phenyl isopropyl ether was not formed

• Carbon letters
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• 제1권1호
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.328-334
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• 2008

The effects of catalyst preparation on the reaction route and the mechanism of biphenol (BP) hydrogenation, which consists of a long series-reaction, were studied. Pd/C catalysts were prepared by incipient wetness method and precipitation and deposition method. The reaction behaviors of the prepared catalysts and a commercial catalyst along with the final product distributions were very different. The choice of the catalyst preparation conditions during precipitation and deposition including the temperature, pH, precursor addition rate, and reducing agent also had significant effects. The reaction behaviors of the catalysts were interpreted in terms of catalyst particle size, metal distribution, and support acidities.

• 한국임상수의학회지
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• 제18권3호
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• pp.211-214
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• 2001

The embolic effect of Gelfoam was investigated for transarterial embolization of renal artery (TAE-RA) in four normal rabbits. The catheter was selectively introduced into the unilateral renal artery under fluoroscopy and the Gelfoam-iohexol mixture was infused through a catheter into the renal arteries of 4 rabbits. The immediate and delayed (8 weeks) embolic effects on the renal arteries was investigated with selective angiography. The Gelfoam-iohexol was visualized under fluorosxopy in four rabbits. Renal arteries were ablated immediately after TAE-RA in four rabbits, however, opacification of renal parenchyma was visualized by injected contrast agent in 3 rabbits at 8 weeks. The Gelfoam-iohexol can be used as a short-term embolic materials for TAE-RA, however it is not adequate for permanent embolization of renal artery.

• 약학회지
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• 제40권3호
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• pp.343-346
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• 1996

The influence of LB20304a, a new fluoroquinolone antibiotic agent, on microflora of caecum in mice was compared with those of ciprofloxacin and piperacillin after administration of drugs for 5 days. Selective medium (CCFMA) was used for the isolation of Clostridium difficile from the specimens of mouse caecum. The emergence of C. difficile in mouse caecum induced by LB20304a was lower than that by ciprofloxacin or piperacillin at day 1 and day 7 after completing administration of drugs.

• 대한화학회지
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• 제17권6호
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• pp.439-443
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• 1973

은에 한하여 대단히 예민한 시약으로서 2-mercaptothiazoline를 알게 되었으며, 이 시약으로 은의 전류법 정량에 뛰어나게 이용할 수 있다. 이 방법은 암모니아 수용액에서 2-mercaptothiazoline으로써 전류법적정에 의한 미량의 은을 정량하는데 EDTA를 막기제로 사용하여 많은 다른 이온들의 존재하에 대기중에서 미량의 은을 직접 적정할 수가 있었으며 방해 이온들은 금과 백금 뿐이나, 미량의 은을 이 방법에 의하여 상대오차 ${\pm}$5% 이내로 정량할 수 있다.

• 대한화학회지
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• 제20권4호
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• pp.277-279
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• 1976

은 전극을 지시전극으로 하고 표준칼로멜 전극을 기준전극으로 하여 전압플로위회로를 이용하여 수용액에서 2,5-dimercapto-1,3,4-thiadiazole에 의한 구리의 전위차 적정법을 연구하였다. 이 시약은 구리의 전위차 적정 정량에 뛰어나게 이용할 수 있었고 여러가지 가리움제를 사용하여 다른 이온들의 존재하에 대기중에서 미량의 구리를 직접 적정할 수 있었다.

• 미생물학회지
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• 제17권1호
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• pp.25-41
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• 1979

A strain able to grow up m-toluate minimal medium has been isolated after selective enrichment and given the name T81X, which was later identified as pseudomonase putida according to its morphological and biochemical characteristics. After treatment with plasmied specific curing agent, mitomycin C, followed by replica plating on m-toluate and xylene minimal agar plate, T81Xstrain has been shown to harbour a curable plasmid relating to the m-toluate and xylene metabolism. Spontaneous curing frquency of this plasmid was also greatly enhanced by growing on benzoate minimal medium. After then, it was also xylene metabogrowing on benzoate minimal medium. After then, it was found to be conjugally nontransmissible. From the comparative investigation of catechol 1,2-oxygenase and catechol 2,3-oxygenase activities in wild type and cured strain on various growth substrate, it appeared that T81X strain has both of these two enzymes while cured strain has catechol 1,2-oxygenase only. Growing on m-toluate minimal medium T81X strain should carry the genetic information necessary for coding the catechol 1,2-oxygense induced by m-toluate or benzoate, on that curable plasmid.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.949-952
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• 2010

A new and efficient reagent for the conversion of primary and secondary alcohols into their corresponding aldehydes and ketones is introduced. The reagent was easily prepared from the reaction of DBU with molecular bromine in $CHCl_3$. The structure of the reagent as $DBUH^+{Br_3}^-$ was determined by single crystal X-ray diffraction analysis.

• 한국응용과학기술학회지
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• 제27권3호
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• pp.273-281
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• 2010

Nickel recovery method was studied by the wet process from the catalyst used in hydrogenation process. Nickel content in waste catalyst was about 16%. At the waste catalyst leaching system by the alkaline solution, selective leaching of nickel was possible by amine complex formation reaction from ammonia water and ammonium chloride mixed leachate. The best leaching condition of nickel from mixed leachate was acquired at the condition of pH 8. LIX65N as chelating solvent extractant was used to recover nickel from alkaline leachate. The purity of recovered nickel was higher than 99.5%, and the whole quantity of nickel was recovered from amine complex.