• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.147-154
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• 2004

It is the aim of this study to propose the fundamental data for the establishment of the application and qualify standard of the mixed type superplasticizer after investigating and comparing the fluidity of high flowing concrete according to the component ratio of superplasticizer such as naphthalene sulfonated and melamine sulfonated. The results of this study were shown as the followings; 1) The fluidity and adsorption ratio of cement-paste were improved according to the increasing of naphthalene sulfonated component ratio, and apparent viscosity of cement-paste was improved according to the Increasing of melamine sulfonated component ratio. 2) In case of using the granulated blast-furnace slag, the fluidity of cement-paste was considerably good and the adsorption ratio was decreased and in case of using fly-ash, the apparent viscosity and adsorption ratio of cement-paste were improved. 3) The dispersive capacity performance of concrete can be improved by means of the increasing of naphthalene sulfonated component ratio. Also the viscosity and early strength can be improved by means of the increasing of melamine sulfonated component ratio.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.162-170
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• 1996

Light cycle Oil(LCO) contains 2,6-dimethylnaphthalene (2,6-DMNA) which is used as the basic material for high performance engineering plastics and liquid crystal polymer. This study was experimentally investigated to concentrate a mixture of dimethylnaphthalene(DMNA) isomers in the LCO by extraction-distillation combination as a pretreatment for separation and purification of 2,6-DMNA in the LCO. Furthermore, concentration of a mixture of DMNA isomers in the LCO compared between distillation and extraction-distillation combination. The recovery of aromatics in the LCO was performed by batch cocurrent multistage extraction with dimethylsulfoxide and water mixture as solvent. The concentration of naphthalene group(carbon number 10-12) in the extracted mixture is higher than that in the LCO. The yield for naphthalene group increased with decreasing carbon number. The yield for a mixture of DMNA isomers obtained in 5 equilibrium extration runs was about 65%. the separation of individual components with extractedmixture was tested by batch distillation. Futhermore, for recovery of a mixture of DMNA isomers of high concentration, distillate containing DMNA was distilled. As a result, a mixture of DMNA isomers with high concentration such as 60wt% was recovered. The extraction-distillation combination was more effective than the distillation to concentration a mixture of DMNA isomer in the LCO.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.305-312
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• 2012

Manila clam, Ruditapes philippinarum (SL; $32.74{\pm}2.18mm$, TW; $8.29{\pm}1.41g$, N; 450) were exposed to various concentrations of naphthalene for 20 weeks. Exposure concentrations of naphthalene established control, solvent control (ethanol), 30, 60, 90 and $120{\mu}g$ Nap $L^{-1}$ following results of 96h acute exposure. After exposure during 20 weeks, survival rate of the manila clam was lowed in 60, 90 and $120{\mu}g$ Nap $L^{-1}$ exposure group compared control group. Also, sex ratio of male was higher in $60{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=5.492$, P < 0.05) but lowed $90{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=4.214$, P < 0.05) and $120{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=30.118$, P < 0.05). Gonad development was delayed in female (> $60{\mu}g$ Nap $L^{-1}$) and male (> $30{\mu}g$ Nap $L^{-1}$). Intersex was 16.28% in female, 1.68% in male. In this result, naphthalene caused survival decrease, imbalance of sex ratio, delay of gonad development of the manila clam. Also, chronic exposure to naphthalene suggested abnormal effects in reproduction of the manila clam.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.1-8
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• 2013

Rockfish, Sebastes schlegeli (total length; $10.36{\pm}0.49cm$, total weight; $16.28{\pm}1.86g$, N; 290) were exposed to various concentrations of naphthalene for 28 days. Exposure concentrations of naphthalene established control, ethanol (solvent) control, 0.5, 1.0, 1.5 and 2.0 mg Nap $L^{-1}$. After exposure, We observed survival rate, and degree of tissue change (DTC) in gill under optical microscopy. Survival rate of the rockfish was more than 90% in control, ethanol control, 0.5 and 1.0 mg Nap $L^{-1}$, whereas it decreased in 1.5 and 2.0 mg Nap $L^{-1}$ (respectively 80%, 62.2%). In histological observation of gill, hyperplasia of epithelial cells observed in all exposure groups. But no showed increase of DTC which was related to concentration. Whereas, DTC at fusion of gill lamellar, lamellar telangiectasia, stasis, aneurysm and necrosis showed dose dependent increase. Especially, fusion of gill lamellar, lamellar telangiectasia and stasis observed at more 1.0 mg Nap $L^{-1}$, and aneurysm and necrosis at more 1.5 mg Nap $L^{-1}$. These results showed naphthalene caused survival and severe change to the gill of the rockfish which was related to exposure concentration.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.665-669
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• 2023

The crude methylnaphthalene oil (CMNO) contains nitrogen compounds (NCs) such as quinoline (QU), isoquinoline (IQU), and indole (IN). These NCs in the CMNO are treated as impurities contained in the CMNO due to contamination of the atmospheric environment and unpleasant odors. In order to improve the quality of CMNO, this study examined the effect of extraction experimental factors on the reduction of NCs contained in CMNO using CMNO as a raw material and an aqueous formamide solution as a solvent, respectively. The increase in the volume ratio of solvent to feed in initial (S/F)₀ in initial increased the distribution coefficient of NCs and the selectivity of NCs in reference to 2-methylnaphthalene (2MNA). Additionally, an increase in operating temperature (T) increased the distribution coefficient of NCs but conversely decreased selectivity. The compositions of QU, IQU, and IN in the raffinate oil recovered through equilibrium extraction under a constant condition (volume fraction of water to solvent in initial (y_w,0) = 0.1, (S/F)₀ = 9, T = 303 K, liquid-liquid contacting time = 72 h) were reduced by about 58.5 wt%, 61.9 wt%, and 73.4 wt%, respectively, compared to those of CMNO. The formamide extraction method in this study was expected to be an effective reduction method for NCs contained in CMNO.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.331-332
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• 2003

Poly(ethylene terephthalate) (PET)는 물리적, 기계적 성질이 우수한 엔지니어링 플라스틱의 하나로 섬유, 필름 및 각종 산업용 소재로 가장 널리 이용되고 있는 고분자 중의 하나이다. 그러나 PET 자체의 성질만으로 고기능성 소재로의 다양한 요구를 충족시키기에는 한계가 있어 PET의 벤젠고리 대신에 나프탈렌 고리로 치환하거나 제 3성분의 2가 알코올을 첨가하여 PET보다 유리전이 온도와 용융 온도가 높고 형태안정성 및 기계적 물성이 우수한 고분자의 개발에 관한 연구가 다수 이루어져 왔다.$^{1.2}$ (중략)

• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.88-90
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• 2003

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.84-86
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• 2000

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.247-250
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• 2002

Poly(ethylene 2,6-naphthalene dicarboxylate)(PEN)은 그 주사슬에 PET의 벤젠고리 대신 나프탈렌 고리로 치환된 구조로 인하여 PEN섬유는 내열성, 탄성계수(modulus), 형태안정성(dimensional stability), 내화학성 등에서 PET에 비해 우수한 장점을 갖고 있으며, 따라서 고온, 고습한 환경에서도 기계적 성질을 오랫동안 유지할 수 있다. 그리고 중합 및 방사 등의 제조 공정이 PET와 유사하여 향후 고강력, 고형 태안정성 산업용사에서 획기적인 변화를 가져올 것으로 기대된다. (중략)

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.25-27
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• 1998

나프탈렌으로부터 제조된 메조페이스 핏치(NMP)와 개질된 등방성 콜타르 핏치(MCP)의 방사성을 유변학적거동에 기초해 설명하고자 시도되었다. 기본적으로, 방사성은 l/4, l/l, 4/1(wt. NMP/wt. MCP)로 블렌드비를 달리 하면서 shear rate를 증가시켰을 때 등방성의 농도가 클 경우 급격한 점도 감소로 cohesive fracture의 원인이 됨을 관찰할 수 있었고 NMP가 증가할수록 탄성에너지 값이 전형적인 고분자의 거동처럼 응답하는 tan $\delta$값의 임계점이 고주파수영역으로 이전되어 최대값을 나타내었고 임계점보다 낮은영역에서 상대적인 크기는 NMP가 증가함에 따라 작아지는 현상을 관찰할 수 있었다.(중략)