• 제목/요약/키워드: naphthalene

검색결과 665건 처리시간 0.025초

염화나프탈렌카르보닐의 친핵성 치환반응에 관한 연구 (Kinetic Studies on Nucleophilic Substitution Reaction for Naphthalene Carbonyl Chloride)

  • 윤상기;엄태섭;성대동
    • 대한화학회지
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    • 제24권5호
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    • pp.347-355
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    • 1980
  • ${\alpha}$- 및 ${\beta}$-염화나프탈렌카르보닐의 가메탄올 분해반응속도를 메탄올-아세톤, 메탄올-아세토니트릴 혼합용매 속에서 측정하였다. 각 혼합용매마다 공통적으로 ${\alpha}$-염화나프탈렌카르보닐이 ${\beta}$-염화나프탈렌카르보닐보다 반응속도 상수가 크게 관측되었다. 이것은 Dewar수 Nr과 Streitwieser의 ${\sigma}^+$값과도 일치하였다. 카르보닐탄소가 천이상태에서 $sp^3$로 바뀌어 인접수소에 의한 입체장애가 없어지는 것을 알 수 있었다.

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Systematic Approaches for Blue Light-emitting Polymers by Introducing Various Naphthalene Linkages into Carbazole Containing PPV Derivatives

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • 제14권5호
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    • pp.258-262
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    • 2013
  • Poly(2,3-naphthalenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), 2,3-PNCPV, poly(2,6-naphthalene vinylenealt- N-ethylhexyl-3,6-carbazolevinylene), 2,6-PNCPV, and poly(1,4-naphthalenevinylene-alt-N-ethylhexyl-3,6- carbazolevinylene), 1,4-PNCPV were synthesized through the Wittig polycondensation reaction. The conjugation lengths of the polymers were controlled by differently linked naphthalenes in the polymer main chain. The resulting polymers were completely soluble in common organic solvents, and exhibited good thermal stability at up to $400^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 357-374 nm and 487-538 nm, respectively. The carbazole and 2,3-linked naphthalene containing 2,3-PNCPV showed a blue PL peak at 487 nm. A single-layer light-emitting diode was fabricated with an ITO/polymer/Al configuration. The electroluminescence (EL) emission of 2,3-PNCPV was shown at 483 nm.

열전달과 물질전달의 유사성에 관한 연구 (A study on the Analogy between Heat Transfer and Mass Transfer)

  • 유성연;노종광;정문기
    • 대한기계학회논문집
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    • 제17권10호
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    • pp.2624-2633
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    • 1993
  • Mass transfer experiment by naphthalene sublimation method has great advantages in measurement of local transfer coefficients in the region of a three dimensional flow or for a model of complex geometry, which is considered to be very difficult with conventional heat transfer measurements. Mass transfer data obtained by naphthalene sublimation technique are converted to the heat transfer data through heat/mass transfer analogy. This analogy is valid for a simple or laminar flow, but new insight is needed when applying to a turbulent flow or complex flow such as separation, reattachment and recirculation, The purpose of this research is to investigate how geometries and flow conditions incorporate heat/mass transfer analogy. Mass transfer experiments are performed using naphthalene sublimation technique for a flat plate, a circular cylinder, and rectangular cylinders. And mass transfer data are compared with earlier heat transfer measurements for the same geometries. Usefulness of analogy relation between heat and mass transfer is examined with these results.

초임계 유체내의 나프탈렌의 용해도 (Solubilities of Naphthalene in Supercritical Fluids)

  • 김정림;김호건;경진범
    • 대한화학회지
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    • 제32권4호
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    • pp.311-317
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    • 1988
  • 임계점 이상의 여러 온도와 압력에서 암모니아내의 나프탈렌의 용해도를 측정함으로써 용해도와 암모니아의 밀도 사이의 관계를 간단한 식으로 나타낼 수 있었다. 이 식을 이용하여 더 높은 압력이나 더 낮은 압력에서의 용해도를 계산할 수가 있으며, 이로부터 용해에 수반되는 에너지 변화와 엔트로피변화를 구하고, 초임계 이산화탄소내의 나프탈렌의 용해도 자료로부터 얻어진 결과와 비교하였다. 또한 나프탈렌과 암모니아 사이의 상호작용 비리알 계수를 결정하여 나프탈렌과 이산화탄소 사이의 경우와 비교 검토하였다.

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$CoL_2(MeOH)(NO_3)_2$의 구조 [L=N1-(1-(pyridin-4-yl)ethylidene)naphthalene-1,5-diamine)] (Structure of [$CoL_2(MeOH)(NO_3)_2$] [L = N1-(1-(pyridin-4-yl)ethylidene)naphthalene-1,5-diamine)])

  • 김성훈;허현수;이순원
    • 한국결정학회지
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    • 제18권1_2호
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    • pp.21-25
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    • 2007
  • Dipyridyl 리간드 L'(N,N'-bis-(1-pyridin-4-yl-ethylidene)-naphthalene-1,5-diamine)을 함유한 $CH_2Cl_2$ 용액을 $Co(NO_3)_2{\cdot}6H_2O$을 함유한 MeOH 용액 위에 깔았을 때, 배위 고분자가 아닌, 분자성 코발트 화합물 [$CoL_2(MeOH)(NO_3)_2$] (1)이 형성되었다. 화합물 1의 X-ray 구조 분석 결과, 이 화합물은 pyridyl-amine 리간드 L(N1-(4-Imino-1-methyl-but-2-enylidene)-naphthalene-1,5-diamine)을 함유하고 있었다. 반응 중에 리간드 L'이 리간드 L로 가수분해되었다는 것을 화합물 1의 구조가 강하게 암시하고 있다.

Lichen-Associated Bacterium, a Novel Bioresource of Polyhydroxyalkanoate (PHA) Production and Simultaneous Degradation of Naphthalene and Anthracene

  • Nahar, Shamsun;Jeong, Min-Hye;Hur, Jae-Seoun
    • Journal of Microbiology and Biotechnology
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    • 제29권1호
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    • pp.79-90
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    • 2019
  • Lichens are generally known as self-sufficient, symbiotic life-forms between fungi and algae/cyanobacteria, and they also provide shelter for a wide range of beneficial bacteria. Currently, bacterial-derived biodegradable polyhydroxyalkanoate (PHA) is grabbing the attention of many researchers as a promising alternative to non-degradable plastics. This study was conducted to develop a new method of PHA production using unexplored lichen-associated bacteria, which can simultaneously degrade two ubiquitous industrial toxins, anthracene and naphthalene. Here, 49 lichen-associated bacteria were isolated and tested for PHA synthesis. During the GC-MS analysis, a potential strain of EL19 was found to be a 3-hydroxyhexanoate (3-HHx) accumulator and identified as Pseudomonas sp. based on the 16S rRNA sequencing. GC analysis revealed that EL19 was capable of accumulating 30.62% and 19.63% of 3-HHx from naphthalene and anthracene, respectively, resulting in significant degradation of 98% and 96% of naphthalene and anthracene, respectively, within seven days. Moreover, the highly expressed phaC gene verified the genetic basis of $PHA_{mcl}$ production under nitrogen starvation conditions. Thus, this study strongly supports the hypothesis that lichen-associated bacteria can detoxify naphthalene and anthracene, store energy for extreme conditions, and probably help the associated lichen to live in extreme conditions. So far, this is the first investigation of lichen-associated bacteria that might utilize harmful toxins as feasible supplements and convert anthracene and naphthalene into eco-friendly 3-HHx. Implementation of the developed method would reduce the production cost of $PHA_{mcl}$ while removing harmful waste products from the environment.

혐기성 미생물에 의한 토양내 다핵성방향족화합물의 생물학적 분해 (Biodegradation of Polynuclear Aromatic Hydrocarbons in soil using microorganisms under anaerobic conditions)

  • 안익성
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.89-91
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    • 2000
  • Polynuclear aromatic hydrocarbon (PAH) compounds are highly carcinogenic chemicals and common groundwater contaminants that are observed to persist in soils. The adherence and slow release of PAHs in soil is an obstacle to remediation and complicates the assessment of cleanup standards and risks. Biological degradation of PAHs in soil has been an area of active research because biological treatment may be less costly than conventional pumping technologies or excavation and thermal treatment. Biological degradation also offers the advantage to transform PAHs into non-toxic products such as biomass and carbon dioxide. Ample evidence exists for aerobic biodegradation of PAHs and many bacteria capable of degrading PAHs have been isolated and characterized. However, the microbial degradation of PAHs in sediments is impaired due to the anaerobic conditions that result from the typically high oxygen demand of the organic material present in the soil, the low solubility of oxygen in water, and the slow mass transfer of oxygen from overlying water to the soil environment. For these reasons, anaerobic microbial degradation technologies could help alleviate sediment PAH contamination and offer significant advantages for cost-efficient in-situ treatment. But very little is known about the potential for anaerobic degradation of PAHs in field soils. The objectives of this research were to assess: (1) the potential for biodegradation of PAH in field aged soils under denitrification conditions, (2) to assess the potential for biodegradation of naphthalene in soil microcosms under denitrifying conditions, and (3) to assess for the existence of microorganisms in field sediments capable of degrading naphthalene via denitrification. Two kinds of soils were used in this research: Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS). Results presented in this seminar indicate possible degradation of PAHs in soil under denitrifying conditions. During the two months of anaerobic degradation, total PAH removal was modest probably due to both the low availability of the PAHs and competition with other more easily degradable sources of carbon in the sediments. For both Harbor Point sediment (HPS-2) and Milwaukee Harbor sediment (MHS), PAH reduction was confined to 3- and 4-ring PAHs. Comparing PAH reductions during two months of aerobic and anaerobic biotreatment of MHS, it was found that extent of PAHreduction for anaerobic treatment was compatible with that for aerobic treatment. Interestingly, removal of PAHs from sediment particle classes (by size and density) followed similar trends for aerobic and anaerobic treatment of MHS. The majority of the PAHs removed during biotreatment came from the clay/silt fraction. In an earlier study it was shown that PAHs associated with the clay/silt fraction in MHS were more available than PAHs associated with coal-derived fraction. Therefore, although total PAH reductions were small, the removal of PAHs from the more easily available sediment fraction (clay/silt) may result in a significant environmental benefit owing to a reduction in total PAH bioavailability. By using naphthalene as a model PAH compound, biodegradation of naphthalene under denitrifying condition was assessed in microcosms containing MHS. Naphthalene spiked into MHS was degraded below detection limit within 20 days with the accompanying reduction of nitrate. With repeated addition of naphthalene and nitrate, naphthalene degradation under nitrate reducing conditions was stable over one month. Nitrite, one of the intermediates of denitrification was detected during the incubation. Also the denitrification activity of the enrichment culture from MHS slurries was verified by monitoring the production of nitrogen gas in solid fluorescence denitrification medium. Microorganisms capable of degrading naphthalene via denitrification were isolated from this enrichment culture.

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