• 공업화학
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• 제8권6호
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• pp.967-972
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• 1997

접촉분해경유(LCO)와 dimethylsulfoxide(DMSO)수용액의 평형추출로부터 얻어진 추출상을 원료로 사용한 역추출에 의해 추출상중의 방향족의 회수를 검토했다. 역추출 용매의 선정을 위해, Benzene, Toluene, m-Xylene(mX), n-Hexane(Hx)과 n-Octane(Ot)을 용매로 사용하여 추출상-용매간의 분배평형을 측정한 결과, 추출상중의 방향족의 회수면에서 Hx이 가장 적절한 용매이었다. 또, Hx을 용매로 사용하여 평형 역추출을 행해 방향족의 회수에 대한 조작인자의 영향을 검토했다. 방향족에 대한 분배계수는 용매/원료(추출상) 질량비(S/F)(S/F를 변화시켜 얻어진 추잔상 혹은 추출상중의 질량분율)에 관계없이 일정했으나 수율은 S/F가 증가함에 따라 증가했다. 조작온도는 방향족의 분배계수와 수율에 영향을 미치지 못했다. 나프탈렌류 성분(탄소수:10~12)간에는 탄소수가 많을수록 분배계수 및 수율이 컸다. 또한, 회분 교반조를 사용하여 역추출을 행해 방향족 성분의 물질이동 속도를 측정했다.

• 자원리싸이클링
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• 제17권6호
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• pp.50-56
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• 2008

Post-consumed플라스틱 중 폐 polypropylene fraction으로 분리된 재료를 이용하여 열분해 실험을 수행하였다. 본 연구의 목적은 열분해 생성오일 중 용제로 사용이 가능한 BTEX-aromatics 수율이 반웅온도에 따라 어떤 영향을 받는지 고찰하는 것이었다. 이를 위하여 열전달이 우수한 유동층 반응기를 이용하여 $650^{\circ}C$에서 $700^{\circ}C$ 사이의 반응온도에서 열분해 실험을 진행하였다. 본 실험에서는 오일생성 극대화를 위해 열분해 반응 중 생성되는 가스를 유동화 가스로 사용하였으며, 유동화 가스의 유량과 시료 투입율은 실험 중에 일정하게 유지하였다. 실험결과 gas, oil 및 char가 반응 생성물로 얻어졌다. 생성 가스는 GCs(TCD, FID)를 사용하여 정량 분석하였고 정성적 분석을 위해서는 GC-MS 시스템을 이용하였다 정확한 분석을 위해서 생성오일은 진공 증류하여 distillation residue를 분리하였으며, 증류한 oil은 GC-MS 통해 정성 및 정량적 분석을 수행하였다. 반응온도가 높아질수록 distillation oil중의 BTEX-aromatics의 함량은 증가하였으며 $695^{\circ}C$에서 약 30% 정도의 함량을 나타내었다. 생성 가스는 대부분 $CH_4$, $C_2H_4$, $C_2H_6$, $C_3H_6$, $C_4H_{10}$로 구성되어 있었으며, 고위 발열량은 약 45 MJ/kg로서 열분해 공정 에너지원이나 기타 연료용 에너지원으로 사용가능할 것으로 평가되었다.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.422-428
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• 1999

Aromatic hydrocarbons can be utilized as carbon and energy sources by some microorganisms at lower concentrations. However, they can also act as stresses to these organisms at higher concentrations. Pseudomonas sp. DJ-12 is capable of degrading 0.5 mM concentration of benzoate and 4-chlorobenzoate (4CBA). In this study, the exposure of Pseudomonas sp. DJ-12 to the pollutant stresses of benzoate and 4CBA at various concentrations was comparatively studied for its cellular responses, including survival tolerance, degradability of the aromatics, and morphological changes. Pseudomonas sp. DJ-12 utilized 0.5 to 1.0mM benzoate and 4CBA as carbon and energy sources for growth. However, the organism could not degrade the aromatics at concentrations of 3 mM or higher, resulting in reduced cell viability due to the destruction of the cell envelopes. Pseudomonas sp. DJ-12 cells produced stress-shock proteins such as DnaK and GroEL when treated with benzoate and 4CBA at concentrations of 0.5mM, or higher as sublethal dosage; Yet, there were differing responses between the cells treated with either benzoate or 4CBA. 4CBA affected the degradability of the cells more critically than benzoate. The DnaK and GroEL stress-shock proteins were produced either by 1mM benzoate with 5 min treatment or by higher concentrations after 10min. The proteins were also induced by 0.5mM 4CBA, however, it needed at least 20min treatment or longer. These results indicate that the chlorination of benzoate increased the recalcitrance of the pollutant aromatics and changed the conditions to lower concentrations and longer treatment times for the production of stress-shock proteins. of stress-shock proteins produced by the aromatics at sublethal concentrations functioned interactively between the aromatics for survival tolerance to lethal concentrations.

• 한국연초학회지
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• 제26권2호
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• pp.102-108
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• 2004

The present study was carried out to compare the composition of major essential oil components in the flue-cured tobacco produced by Korea, America, China, Brazil and Zimbabwe. Above 100 essential oil components were separated by GC and major 18 components of them, known to be important contributors to flue-cured tobacco flavor and smoke taste, were identified by GC/MS. Neophytadiene was major in quantities in the oils mostly and its composition in flue-cured tobacco produced by Korea, America, Zimbabwe, Brazil, and Unnam and Yenji region of China was 26.82\%,\;25.17\%,\;26.50\%,\;16.92\%,\;and\;18.75\%\;and\;14.87\%$, respectively. Megastigmatrienone, one of the major tobacco carotenoid degradation products was contained above $10\%$ in the oils of flue-cured tobacco produced by Korea and America, but, it was comprised about $5.66\%$ to 8.00 in Brazil, Zimbabwe, and Unnam and Yenji region of China. Damascenone is important to the aroma of tobacco as a crotenoid degradation products. Its amount in the oils was $3.31\%\;in\;Brazil,\;3.13\%\;in\;America,\;2.57\%\;in\;Zimbabwe,\;2.54%$ in Yenji of China, $2.00\%$ in Korea and $1.85\%$ in Unnam of China. These results can furnish the basic information capable of evaluating the quality value of flue-cured tobacco produced by various nations.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2642-2646
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• 2012

Pretreatment of spent FCC catalyst and its application in remove trace olefins in aromatics were investigated in this research. The most effective pretreatment route of spent FCC catalyst was calcining at $700^{\circ}C$ for 1 h, washing with 5% oxalic acid solution in ultrasonic reactor and dried. Treated spent FCC catalyst was modified with metal halides, then to prepare catalyst to remove trace olefins in aromatics. X-ray diffraction, Pyridine-FTIR, $N_2$ adsorption-desorption and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to investigate the pretreatment process. The result showed that the performance of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst, which indicted the possibility and improvement of this research.

• 한국대기환경학회지
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• 제14권5호
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• pp.507-518
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• 1998

A field comparison study was carried out to quantify differences among various sampling and analytical methods for volatile organic compounds (VOCs) at a site in Vlsan in June 1997. Air sampling containers (SUMMA canisters) were used by the Korea Institute of Science and Technology (KIST) and adsorption tubes (carbotrap) were used by Yeungnam University (YN Univ.) for sampling ambient air. Duplicate samples obtained by KIST were analyzed by KIST with a GC-MS system for aromatics and halogenated hydrocarbons and by Atm AA with a GC -FID system for C2∼C9 hydrocarbons, respectively. The adsorption tube samples were analyzed by YN Univ. with a GC-FID system for aromatics. VOC levels for the duplicate canister sampls analyzed by KIST and Atm AA were in good agreement. Concentrations of aromatics by the adsroption tube method were generally higher than those by the canister sampling method by factor of 1.5 to 2.0. Differences between the two sampling methods were discussed.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.161-161
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• 2006

New polymeric and oligomeric OTFT materials containing fused aromatics such as anthracene and naphthalene have been designed, synthesized and characterized. The new OTFT materials were prepared by palladium-catalyzed Suzuki cross-coupling reaction. The obtained materials were characterized by various spectroscopic methods such as UV-vis, PL, cyclovoltametry, and XRD. The obtained OTFT materials containing fused aromatics showed high thermal stability above $350^{\circ}C$ In OTFT devices using new materials, high charge carrier mobility and on/off ratio were observed.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.8.1-8.9
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• 2018

Background: Indiscriminate use of antibiotics in livestock and poultry farming has caused emergence of new pathogenic strains. The situation has warrented the development of safe and alternative growth promoters and immunity enhancers in livestock. Herbal additives in animal and bird feed is a centuries-old practice. Thus, the present study investigated the efficacy of a standardized formulation of lipophilic turmeric extract containing curcumin and turmerones, (TF-36), as a natural growth promoter poultry feed additive. Methods: The study was designed on 180 one-day old chicks, assigned into three groups. Control group ($T_0$) kept on basal diet and supplemented groups $T_{0.5}$ and $T_1$ fed with 0.5% and 1% TF-36 fortified basal diet for 42 days. Each dietary group consisted of six replicates of ten birds. Body weight, food intake, food conversion ratio, skin colour, blood biochemical analysis and antioxidant status of serum were investigated. Results: Body weight improved significantly in $T_1$ with a 10% decrease in FCR as compared to the control. TF-36 supplementation in $T_1$ enhanced the antioxidant enzyme activity significantly (p < 0.05) with a decrease (p < 0.05) in lipid peroxidation. It also caused a slight yellow skin pigmentation without any change in meat color, indicating the bioavailability of curcumin from TF-36. However, no significant change in the concentration of serum creatinine, total protein and liver enzyme activities were observed, indicating the safety. Conclusion: In summary, we concluded that TF-36 can be a natural feed additive to improve growth performance in poultry, probably due to the better antioxidant activity and antimicrobial effects contributed by the better bioavailability of curcuminoids and turmerones. Besides, curcuminoids and turmerones were also known to be gastroprotective and anti-inflammatory agents.

• 대한화학회지
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• 제29권6호
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• pp.575-581
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• 1985

벤젠, 나프탈렌 및 페난스렌과 요오드 사이의 각계를 사염화 탄소 용액에서 자외선 분광광도법에 의하여 연구한 결과 1:1분자 착물이 형성됨을 알았다. 이들 착물 생성에 의한 흡수 최대는 온도가 상승함에 따라 blue shift되므로 이에 따른 각 온도에서의 평형 상수를 구하였다. 이 값으로부터 이들 착물 생성에 대한 열역학적 파라미터를 산출한 결과 각 온도에서 여러 고리 방향족화합물과 요오드 사이에 생성된 착물의 상대적 안정도는 방향족 고리의 수가 증가함에 따라 증가함을 알 수 있다. 이러한 사실을 요오드에 대한 여러 고리 방향족 화합물들의 상대적 염기성도를 나타내며 방향족 화합물과 요오드 사이의 상호작용에 관한 공명현상에 의하여 설명할 수 있다. 그리고 이 계열의 연구결과를 폴리메틸 벤젠계열의 연구결과와 비교 고찰하였다.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3241-3247
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• 2012

Ionic liquids (ILs) have been extensively investigated as promising alternatives to conventional organic solvents such as sulfolane and N,N-dimethylformamide for the selective extraction of aromatic hydrocarbons from the $C_6-C_{10}$ hydrocarbon mixtures produced from the cracking processes of naphtha and light oils. The most important advantage of ILs over conventional organic solvents is that they are immiscible with aliphatic hydrocarbons, and thus the back extraction of ILs from the raffinate phases and top hydrocarbon-rich layers is not necessary. In this paper, a brief review on the state of the art in the utilization of ILs for aromatics separation is presented.