• Title/Summary/Keyword: Recyclable

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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.

Selection of Environmentally Conscious Manufacturing's Program Using Multi-Criteria Decision Making: A Case Study in Electronic Company

  • Sutapa, I. Nyoman;Panjaitan, Togar W.S.
    • Industrial Engineering and Management Systems
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    • v.10 no.2
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    • pp.123-127
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    • 2011
  • Nowadays, green purchasing, stop global warming, love the mother earth, and others that related to environment become hot issues. Manufactures industries tend to more active and responsive to those issues by adopting green strategies or program like Environmentally Conscious Manufacturing (ECM). In this article, an electronic company had applied 12 ECM Program and tries to choose one of those programs using 6 criteria, such as total cost involved, quality, recyclable material, process waste reduction, packaging waste reduction, and regulation compliance. By using multi-criteria decision making model, i.e. Analytical Hierarchy Process (AHP), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and Modified TOPSIS methods, the ECM Program 9 (Open pit) is the best option.

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.

A Study on the Architectural Characteristics of ¡?Verbena Heights¡?Estate in Hong Kong (홍콩 버비나하이츠(Verbena Heights) 주거단지의 특징에 관한 연구)

  • 이재훈;김남응;김성화
    • Journal of the Korean housing association
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    • v.13 no.3
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    • pp.21-31
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    • 2002
  • The purpose of this study is to find the architectural characteristics of Verbena Heights, super high-rise complex housing, which has been most highly evaluated as a new town development model in Hong Kong, as a successful case of new housing type and sustainable design. The analyzed features of Verbena Heights are as follows; 1) Formation of various open spaces by a creative layout. 2) Enhancement of natural ventilation and daylighting by a linear plan instead of conventional cruciform plans. 3) Applications of integrated facade design for noise mitigation and for sunlight shading. 4) Adoption of energy-efficient devices, use of recyclable materials, and improvement of livability by a sustainable design process. These architectural characteristics provide the high-density high-rise housing with more efficient and comfortable environments for residents. And it is proved that the sustainable design can enhance the quality of dwelling environment.

Pressure Distribution Simulation on Geometrical Manifolds Structure for Fabrication of a Planar-type Fuel-Cell Stack (평판형 연료전지 스택의 제조를 위한 매니폴드 형상별 압력분포 시뮬레이션)

  • Park, Se-Joon;Choi, Young-Sung;Lee, Kyung-Sup
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.609-614
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    • 2009
  • A fuel-cell power system among various alternative power sources has many advantages such as comparatively independable circumstances, high-efficient, and heat-recyclable, thus it is now able to be up to hundreds MWh-scaled through improving feasibility and longevity of it. During the last few decades, numerous research results has been investigated to expand interest in fuel-cell technology. This study presents pressure distribution on the geometrical manifold structures, which are U-type and Z-type, of a planar-type fuel-cell stack by simulated with computational fluid dynamics(CFD). Then, electrical performance of a 200W fuel-cell stack, which is U-type, was diagnosed after pre-conditioning operation. The stack has electrical characteristics ; 22V, 10A, 220W, and current density $200mA/cm^2$.

Value-added Polyolefin Products

  • Ok, Myung-Ahn
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.152-152
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    • 2006
  • Polyolefins show a very healthy growth rate among commodity polymer resins due to their low feedstock prices, recyclable and environmentally friendly characteristics and easily controllable performances. Capacity investment in polyolefin field is now moving from technology region to consumer region and feedstock region. Therefore, key success factors for polyolefin business in the other region such as Korea are cost reduction, development of highly value-added products and new applications and substitution of PVC, PS, PET and other EPs. To add additional value to commodity polyolefin products, high level of platform technology such as catalyst, process and structure-properties relationship is needed. Progress on polyolefin products has been very closely related to catalyst and process technology. According to this trend, SK Corporation has devoted a lot of research effort into development of new value-added polyolefin products based on the proprietary technology platform.

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Novel Tri- and Tetra-substituted Pyrimido[4,5-d]pyridazines: Regiospecific Synthesis Catalyzed by Silica Supported Yttrium Trinitrate

  • Karami, Bahador;Akrami, Sedigheh;Khodabakhshi, Saeed
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3677-3680
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    • 2013
  • Novel tri- and tetra-substituted pyrimido[4,5-d]pyridazines-2(1H,3H,7H)-ones have been synthesized via the regiospecific condensation reaction of hydrazine derivatives with 5-acetyl-4-aryloyl-6-methyl-3,4-dihydropyrimidinones in the presence of $SiO_2-Y(NO_3)_3$ as a green and recyclable catalyst under solvent-free conditions. All products were obtained in high yields and short reaction time. Employing this method is in accord with green chemistry principles.

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.