• Title, Summary, Keyword: Recyclable

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Effective Separation Method of NBD Dimer Mixture (NBD 이량체 생성물의 효율적 분리방법)

  • Jeong, Byung-Hun;Han, Jeong-Sik;Min, Seong-Ki;Lim, Jin-Shik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.797-799
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    • 2010
  • In preparation of NBD dimer, one of the industrially useful multicyclic hydrocarbon compound, various catalyst, solvent and byproducts were included in reaction product at the end of dimerization reaction. In order to increase the yield of NBD dimer mixture, first of all, effective separation process development was required. The research for improvement of NBD dimer yield were performed by use of eco-friendly and recyclable separation solvent.

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Fabrication of Hollow Metal Microcapsules with Mesoporous Shell Structure: Application as Efficient Catalysts Recyclable by Simple Magnetic Separation

  • Jang, Da-Young;Jang, Hyung-Gyu;Kim, Gye-Ryung;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3274-3280
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    • 2011
  • Monodispersed porous NiO and $Co_3O_4$ microcapsules with a hollow core were synthesized using SBA-16 silica sol and PS as a hard template. The porous hollow microcapsules were characterized by XRD, TEM and $N_2$ adsorption/desorption analysis. After $H_2$ reduction of metal oxide microspheres, they were conducted as an active catalyst in the reduction of chiral butylronitrile and cyanobenzene. The mesoporous metals having a hollow structure showed a higher activity than a nonporous metal powder and an impregnated metal on the carbon support.

Selective Oxidation of Cyclohexane at Low Temperature by Fe-Pd Bicatalytic Systems: $FeCl_2$-Pd/alumina System and Pd/$Fe_2O_3$ System

  • 전기원;Lingaiah Nakka;김상범;이규완
    • Bulletin of the Korean Chemical Society
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    • v.18 no.12
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    • pp.1269-1273
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    • 1997
  • The system which employs iron, palladium, molecular oxygen and hydrogen as a model mono-oxygenase, has been investigated to develop a new method for selective cyclohexane oxidation uner mild conditions. This system provides much higher yield and selectivity for the formation of cyclohexanol and cyclohexanone compared to that of the existing industrial method. When the catalytic system, FeCl2-Pd/alumina, was employed, the oxidation system required acetone as a solvent to be efficient and acidifying the solvent by a little addition of acetic acid or HCl made the system more efficient. The Pd catalyst was recyclable without a significant deactivation but the recycling of ferrous chloride showed the decrease in the activity. On the other hand, the heterogeneous catalytic system, Pd/Fe2O3 could be recovered easily and reused after drying treatment.

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An Experimental Study on Compressive Strength of Lightweight Concrete made of Polystyrene Foam Balls (Polystyrene Beads를 이용한 경량콘크리트의 강도특성에 관한 실험적 연구)

  • Lee, Kyeong-Dong;Han, Jae-Ik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.2
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    • pp.155-160
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    • 1999
  • Recently, the study on mix design of lightweight concrete using the polystyrene foam balls is put into practice from the viewpoint to grade up the quality of concrete and recyclable usage of industrial by products. Polystyrene aggregate concrete, PAC, can be used as structural concrete in low strength application. For instance, PAC could be used in the middle part of sandwich panel where stresses are generally low and in the case of grid-type reinforcement where it does not need high bond strength but little compressive strength to resist the pressure of transverse reinforcement. From this point of view, the authors discussed the influence of fluidity and compressive strength of concrete by the difference of the volume percentage of polystyrene foam balls and water cement ratio.

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Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Using HClO4-SiO2 as a Heterogeneous and Recyclable Catalyst

  • Maheswara, Muchchintala;Oh, Sang-Hyun;Kim, Ke-Tack;Do, Jung-Yun
    • Bulletin of the Korean Chemical Society
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    • v.29 no.9
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    • pp.1752-1754
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    • 2008
  • A simple and efficient synthesis of 3,4-dihydropyrimidinones or thiones is described, using silica-supported perchloric acid ($HClO_4-SiO_2$) as a heterogeneous catalyst from an aldehyde, $\beta$-dicarbonyl compound, and urea or thiourea under solvent-free conditions. Compared to the classical Biginelli reactions, this method consistently has the advantage of high yields, short reaction time, easy separation, and tolerance towards various functional groups.

Recyclable Porphyrin Catalyst with Core-shell Nanostructure

  • Choi, Bo-Gyu;Ko, Soo-Y.;Nam, Won-Woo;Jeong, Byeong-Moon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1819-1822
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    • 2005
  • In the search for a simple preparation method of heterogeneous catalyst, the iron porphyrins were coordinated bonded to the surface of a polymeric core-shell nanosphere. The heterogeneous catalyst was characterized by FT-IR, scanning electron microscope, and UV-vis spectrophotometer. The iron porphyrin bound core-shell nanospheres was about 470 nm in diameter and their catalytic activity for cyclohexene oxidation was similar to a homogeneous iron porphyrin in a solvent composition range of 25-75% acetonitrile/water (v/v). In addition, they could be recovered by simple centrifugation and their catalytic activity was maintained more than the third cycle.

Scolecite Catalyzed Facile and Efficient Synthesis of Polyhydroquinoline Derivatives through Hantzsch Multi-component Condensation

  • Gadekar, Lakshman S.;Katkar, Santosh S.;Mane, Shivshankar R.;Arbad, Balasaheb R.;Lande, Machhindra K.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2532-2534
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    • 2009
  • A facile and efficient synthetic route has been developed for the polyhydroquinoline via four component reactions of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of catalytic amount of scolecite in ethanol at 70 ${^{\circ}C}$ through Hantzsch reaction. This method gives remarkable advantages such as simple work-up procedure, environmentally friendly, inexpensive, non-toxic and recyclable catalyst, shorter reaction time along with excellent yields.

A Study on Electric Properties and Accelerated Water Tree Degradation of Environmental-friendly Non-crosslinked Polyethylene (친환경 비가교 폴리에틸렌의 전기적 특성과 워터트리 가속열화에 관한 연구)

  • Lee, June-Ho;Kong, Tae-Sik;Kim, Seong-Jung;Kwon, Ki-Hyung;Lee, Jae-Soon;Gu, Gwang-Hoe;Cho, Kyu-Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.6
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    • pp.827-832
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    • 2012
  • The crosslinked polyethylene (XLPE) is the most widely used insulating material for power cable. Due to its thermosetting characteristics, the XLPE can not be recycled, while the needs for the environmental friendly and recyclable insulator is rapidly increasing. In this paper, some important and basic electrical properties of non-crosslinked polyethylene such as conduction current characteristics, water the tree characteristics, AC breakdown test were experimentally investigated. It was shown that some of the tested samples had better performances from the application point of view for replacing current XLPE.

Analysis of Electrical Characteristics and Performance of Ballast for Dual Lamps (이등용 안정기의 전기적 특성 및 성능 분석)

  • Park, Yong-San;Ji, Pyeong-Shik
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.2
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    • pp.79-83
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    • 2013
  • An electronic ballast and magnetic ballast are two major types of ballasts used in HID(High Intensity Discharge) lamp. Compared with magnetic ballasts which can last for over 30 years and are recyclable at the end of their long lifetime, electronic ballasts have very short lifetimes due to the use of the electronic devices. In this paper, we developed a magnetic ballast for dual lamps and analyzed electrical characteristics and efficiency. As the experimental results, we confirm that the magnetic ballast for dual lamps makes it possible to effectively reduce current, active and reactive powers than conventional ballast.

Local activation using traditional knowledge and ecological resources of Korean islands

  • Hong, Sun-Kee
    • Journal of Ecology and Environment
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    • v.38 no.2
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    • pp.263-269
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    • 2015
  • When we consider changes in agro-fishery systems instigated by environmental changes in islands, rise in sea levels, and natural disasters such as tsunamis, there is an urgent need to carry out initiatives to enhance life standard and conserve ecosystem in island and coastal regions. To protect the region's landscape from the effects of climate change, it is necessary to develop an integrated management system for ecosystem conservation, human settlements, and the local economy. This paper discusses the outline of a preliminary national plan for a sustainable island management system for remote (inhabited and uninhabited) islands in Korea. Two main ideas to enhance life standard are adapting to the natural environment by applying traditional knowledge and utilizing ecological resources of islands, i.e., improving the quality of life and creating added value. As a technique for improving the quality of life, the establishment of eco-villages based on energy-efficient passive houses and ecological welfare is suggested. Another technique for creating added value, the development of sea-farming islands that utilize islands' new recyclable energy is also proposed. Finally, the suggested ideas are discussed in relation to island ecotourism and carbon zero islands.