• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.103-105
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• 2012

With blast-furnace slag is a by-product generated when pig iron is produced. It has been used as the concrete admixture due to high reactivity. However, It causes low strength development during early age. In order to make up for this drawback, in this study, we evaluated compressive strength of mortar replaced with high volume blast-furnace slag. Experimental results, Compressive strength of mortar based on blast-furnace slag is affected by cement type, substitution rate of blast-furnace slag and pH after mixing.

• 한국염색가공학회지
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• 제10권6호
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• pp.49-54
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• 1998

The antimicrobial activities of the copolymer of N,N'-dimethyl-N,N'-diallyl ammonium chloride (DMDAAC) and acrylamide(AA) were investigated. A series of copolymers with various ratios of DMDAAC and AA were prepared by free radical initiation via an intra-intermolecular propagation mechanism, ie, cyclopolymerization, and the antimicrobial activities of the prepared copolymers were measured by minimum inhibitory concentration(MIC) test. The copolymers were, then, methylolated under basic condition for reactivity with hydroxyl group of cellulose. Both antimicrobial activity and fastness to laundering of the cotton fabrics finished using the methylolated copolymers were evaluated. From the results it was shown that the copolymers with different ratios of DMDAAC and AA have MIC values in the range of 1∼100ppm. As the ratio of AA in the copolymers increases, the anitmicrobial activity decreases. The fastness of the cotton fabric finished by the methyolated copolymers to 10 repeated launderings in anionic commercial detergent is good enough to show colony reduction above 90％ regardless of DMDAAC and AA ratios.

• 한국염색가공학회지
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• 제4권3호
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• pp.116-121
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• 1992

This paper is on for a material to replace the petroleum-based resins used as adhesives for the fiber in rubber composite materials. The study limited to the reaction properties of tannin with formaldehyde. Tannin-formaldehyde(TF) reactions were carried out in aqueous media. Rates of reaction were strongly dependent on concentration, temperature, pH, and the mole ratio of tannin to formaldehyde. Viscosities of reaction mixtures were followed up to gelation. The reactivity of tannin-formaldehyde resins was greater than that of resorcinol-formaldehyde resins. To formulate an adhesive, a styrene-butadiene-vinyl pyridine terpolymer latex(L) was added to the TF. This preliminary results suggest that the condensed tannins have considerable promise as substitutes for resorcinol used in resin formulation for bonding of fiber to rubber.

• 대한화학회지
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• 제12권1호
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• pp.35-38
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• 1968

Radio iodination of various aromatic derivatives (aniline, toluene, iodobenzene, acetanilide, benzene, benzoic acid) were achieved at low temperature by a chloroamine-T procedures in presence of polar solvent(dioxane). Organic base (piperidine) was used as the catalyst. Iodine replacement reaction had occured on the aromatic or alicyclic ring by this reaction, and the kind and ratio of iodinated products were proved to be different from those of usual iodide reaction in organic solvent at low temperature. The reactivity of various aromatic or alicyclic compounds towards the present iodination system was evaluated and the scope and limitation of the present procedures in the preparation of radio pharmaceuticals were discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.95-101
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• 1999

This study was performed to evaluate the characteristics of workability and strength of the concrete containing mineral admixtures such as flyash, blast furnace slag, zeolite powder. As a result, considering their workability and strength, the optimum replacement ratio of them to plain concrete were obtained for each ternary admixture. This increased compressive strength was ascribed to both the closer parkinof fine particles and pozzolan reactivity of powders. This work showed that could be effectively utilized as a blending material without any decrease in the strength of early hydration stage. On the other hand, we found that the compressive strength at early ages ternary ordinary and high strength concrete untill 7 days was small, but that ternary concrete at 28days was highly increased about 31% and 15% extent.

• Nuclear Engineering and Technology
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• 제14권4호
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• pp.163-171
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• 1982

평가핵자료파일 ENDF/B-IV 및 ENDL-78과 군정수 계산용 전산코드 ETOX-K4를 이용하여 고속로 핵계산을 위한 ABBN형 26군 군정수쎄트 KAERI-26G를 생산하였다. 이 쎄트를 이용하여 여러형태의 고속임계로심들에 대한 유효증배계수, 반응율비, 반응-도계수등의 적분실험치를 해석하고 기 연구발표된 같은 형의 군정수쎄트에 대한 연구결과와도 비교하여 생산된 군정수쎄트의 신뢰도를 평가하였다.

• 한국대기환경학회지
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• 제22권3호
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• pp.361-371
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• 2006

This study examines ozone episodes occurred during the intensive sampling periods (Jun. 1-30, 2004) in the air of Seoul metropolitan area. During that period, there were 8 events (or days) in which 1 hr averaged ozone concentrations were greater than 100 ppbv. The photochemical analysis of ozone chemistry (i.e., budget and formation and destruction strengths of ozone) was carried out using a photochemical box model. Peaks in diurnal ozone variations during ozone episode periods occurred were concurrent with the sudden change of the slope of $NO_{2}/NO$ ratio, suggesting significant correlation with photochemical reactivity. In addition, the ozone peaks were concurrent with high concentrations of ozone precursors, peroxy radicals of $HO_{2},\;CH_{3}O_{2},\;and\;RO_{2}$. High ozone levels during the ozone episodes are likely to be affected by ozone destruction rate.

• 한국안전학회지
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• 제13권3호
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• pp.45-50
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• 1998

The low grade domestic kaoline, such as pink-C and white-D, was converted to metakaoline, which has pozzolanic reactivity by heat treatment in the temperature range of $600^{\circ}C$ to 100$0^{\circ}C$ for preparing the spacer. The spacer was used for supporting the reinforced steel rod during construction to improve the safety of architecture. Pink-C and white-D were completely dehydroxylated when burnt at 80$0^{\circ}C$ for 1 hour and converted to metakaoline. The compressive strengths of specimens added calcined pink-C were lower than those of press molding mortar products inspite of calcining conditions. When white-D with calcined 80$0^{\circ}C$ and 100$0^{\circ}C$ for 1 hour was mixed 30% in the weight ratio of cement, the specimens cured 28 days had 338 $kg/cm^2$ and 347 $kg/cm^2$ of compressive strengths, respectively.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.25-28
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• 2013

This study presents both experimental and numerical investigation of ignition characteristics of n-heptane and n-butanol mixture. The $O_2$ concentration was fixed to 9-10% to make high exhaust gas recirculation(EGR) rate condition. Experiments were performed using a rapid compression machine. In addition, a numerical study of the ignition delay time was performed using CHEMKIN codes to validate experimental results and predict chemical species after combustion process. The results showed that the ignition delay time increased with increasing n-butanol ratio and the reactivity decreased by low $O_2$ concentration.

• Bulletin of the Korean Chemical Society
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• 제18권8호
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• pp.824-827
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• 1997

Bis(ethylene)rhodium(Ⅰ) chloride dimer reacted with vinylcyclopropane to give σ,η3-allylrhodium(Ⅲ) complex 3. Complex 3 underwent C-C bond cleavage of 8-quinolinyl ethyl ketone 11, to form η3-1,3-dimethylallylrhodium(Ⅲ) complex 8, which was reductively eliminated by trimethyl phosphite to give 8-quinolinyl-1-methylbut-2-enyl ketone (10). More sterically hindered 8-quinolinyl alkyl ketones were allowed to react with complex 3 to afford corresponding alkenes as well as a mixture of complex 8 and η3-1-ethylallyl rhodium(Ⅲ) complex 19, identified as 10 and 8-quinolinyl-pent-2-enyl ketone (20) after reductive elimination. 8-Quinolinyl alkyl ketone bearing a sterically hindered alkyl group showed less reactivity for C-C bond cleavage and higher 20/10 ratio compared with those having a less sterically hindered alkyl group, such as 8-quinolinyl ethyl ketone (11).