• Title/Summary/Keyword: Stability of oxidation

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Catalytic Combustion System Stability : Active Centre with High Temperature Heat Exchanger (촉매연소 시스템 안정화 : 고온용 열교환기를 이용한 능동제어)

  • 유상필;송광섭;류인수
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2002.11a
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    • pp.133-140
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    • 2002
  • Catalytic combustion known as one of the traditional oxidation methods of VOC gas is restricted to its applicable fields because of its reaction characteristics. But recently innovative improvement of catalytic endurance makes its applicable range broader from MEMs to industrial power generation. Therefore, control technologies based on the catalytic combustion characteristics are researched and developed dynamically. Especially, the stable control of catalytic combustion is an essential factor in a view of maximizing its efficiency. In this research, the fuel equivalence ratio and the preheating temperature of mixture gas is controlled by catalytic combustion system enhanced in heat transfer with high temperature heat exchanger. As a result the combustion characteristics of system was investigated, and both passive and active control type were compared and analyzed.

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C-NMR Spectroscopic Study of Alkylbenzenes as Synthetic Lubricant Base Stocks (합성기유로서의 알킨벤젠의 $^{13}$C-NMR분광학적 연구)

  • 최주환;전용진;최웅수;권오관
    • Tribology and Lubricants
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    • v.9 no.2
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    • pp.16-21
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    • 1993
  • Alkylbenzenes used as the synthetic lubricant base stocks were composed of the mixture of the various kinds of aromatic hydrocarbons. Their compositions have affected on the quality of synthetic alkylbenzene lubricants. Therefore, the rapid and accurate methods for the composit ional analysis are important. In this study, the compositions of the alkylbenzenes (Hv. LAB, FHv. LAB, Hv, BAB, DAB[HF], DAB[$AlCl_3$]) as synthetic base stocks have been investigated according to six average structural parameters(Tar, Nal, Asub, $\bar{n}$, nb, $T\alpha$) in the view of the molecular structures by $^{13}C-NMR$ spectroscopy. The experimental results of the oxidation $\varepsilon$ thermal stability tests have been related to the results of the molecular structural analysis.

Catalytic Combustion System Stability:Active Control with High Temperature Heat Exchanger (촉매연소 시스템 안정화 : 고온용 열교환기를 이용한 능동제어)

  • Yu, Sang-Phil;Song, Kwang-Sup
    • 한국연소학회:학술대회논문집
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    • 2002.11a
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    • pp.65-69
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    • 2002
  • Catalytic combustion known as one of the traditional oxidation methods of VOC gas is restricted to its applicable fields because of its reaction characteristics. But recently innovative improvement of catalytic endurance makes its applicable range broader from MEMs to industrial power generation. Therefore, control technologies based on the catalytic combustion characteristics are researched and developed dynamically. Especially, the stable control of catalytic combustion is an essential factor in a view of maximizing its efficiency. In this research, the fuel equivalence ratio and the preheating temperature of mixture gas is controlled by catalytic combustion system enhanced in heat transfer with high temperature heat exchanger. As a result, the combustion characteristics of system was investigated, and both passive and active control type were compared and analyzed.

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Study on Electrical Characteristics of Chloromethylated Polyimide

  • Yu, I.H.;Zhong, Z-X;Lee, M.H.;Lee, S.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.472-475
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    • 2005
  • The electrical performances of liquid crystal (LC) cells with chloromethylated polyimide (CMPI) alignment layers were investigated. The CMPI layer was previously reported as a multifunctional layer that does role of LC alignment and planarization layer as well as photo-alignment material with high photosensitivity and excellent thermal stability. The capacitance-voltage (C-V) characteristics of LC cells with CMPI alignment layers were measured. Mechanical rubbing of the CMPI layer did not generate much difference in residual DC when compared to commercial PI. However, the LC cell with photo-oxidation CMPI layer shows a high residual DC value and a corresponding low voltage holding ratio (VHR) due to the photo-induced ionic charges on the alignment layer.

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Advantages and Applications of Synthetic Greases

  • Kimura, Hiroshi;Onuki, Yuji
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.347-348
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    • 2002
  • The numbers of synthetic greases have been developed with synthetic oils because of their excellent performance factors including thermal/oxidation stability, low-temperature fluidity and plastic compatibility. Long life under high-temperature condition and excellent low-temperature fluidity are required to serve as grease for bearings of engine room electrical component. As many plastics are used in place of metals for the purpose of weight saving, synthetic hydrocarbon grease is in use to avoid adverse effect on plastics. Other various special synthetic greases are also in use depending on specific requirements like conductivity and vacuum condition.

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The Polyaniline Electrode Doped with Li Salt and Protonic Acid in Lithium Secondary Battery

  • Ryu, Kwang-Sun;Kim, Kwang-Man;Hong, Young-Sik;Park, Yong-Joon;Jang, Soon-Ho
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1144-1148
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    • 2002
  • We prepared the polyaniline (Pani) film and powder by chemical polymerization and doping with different dopants and also investigated the capability of Li//polyaniline cells after assembling. The oxidation/reduction potentials and electrochemical reaction of Li//polyaniline cells were tested by cyclic voltammetry technique. The Li//Pani-HCl cells with 10% and 20% conductors show a little larger specific discharge capacities than that without conductor. The highest discharge capacity of almost 50 mAh/g at 100th cycle is also achieved. However, Li//Pani-LiPF6 with 20% conductor shows a remarkable performance of ~90 mAh/g at 100th cycle. This is feasible value for using as the positive electrode material of lithium ion secondary batteries. It is also proved that the powder type electrode of Pani is better to use than the film type one to improve the specific discharge capacity and its stability with cycle.

The Radiation Resistance Evaluation of Electrically Insulating Polymers

  • Lee, Dong-Hoon;Jung, Chan-Hee;Hwang, In-Tae;Choi, Jae-Hak;Im, Don-Sun;Kim, Ki-Yup;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.5 no.3
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    • pp.237-242
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    • 2011
  • In this research, the radiation resistance of ethylene propylene rubber (EPR) and chlorosulfonated polyethylene (CSPE) which can be used as a insulating materials of for electrical cable in the nuclear power plant were investigated. EPR and CSPE were irradiated by ${\gamma}$-ray at various doses ranging from 50 to 500 kGy at room temperature in air. The irradiated EPR and CSPE was investigated in terms of activation energy, mechanical properties, and oxidation stability. The experimental results revealed that CSPE exhibited the higher radiation resistance in comparison to that of EPR.

Solar-hydrogen Production by a Monolithic Photovoltaic-electrolytic Cell

  • Jeon, Hyo Sang;Min, Byoung Koun
    • Journal of Electrochemical Science and Technology
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    • v.3 no.4
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    • pp.149-153
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    • 2012
  • Among the various solar-hydrogen production techniques a combination of a photovoltaic (PV) and an electrolytic cell into one single system, a monolithic PV-electrolytic cell, has been suggested as a promising one in terms of efficiency and stability. In this mini-review, we describe our recent efforts on the fabrication of the monolithic PV-electrolytic cell. Particularly, we focus on the electrocatalysts for water oxidation and its fabrication method suitable for a monolithic PV-electrolytic cell. We also introduce proto-type devices with a dye-sensitized solar cell module and an InGaP/GaAs photoelectrodes.

Noncovalent Titania Wrapping of Single-Walled Carbon Nanotubes for Environmentally Stable Transparent Conductive Thin Films (환경신뢰성이 확보된 투명전도성 필름을 위한 비공유 걸합에 의한 단일벽 탄소나노튜브의 $TiO_2$ 코팅)

  • Han, Joong-Tark;Kim, Jun-Suk;Jeong, Hae-Deuk;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.20-20
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    • 2010
  • We present a simple process for the fabrication of high performance transparent conducting films that contain single-walled carbon nanotubes (SWCNTs) noncovalently coated with an ultrathin titania layer. The hydrophobic interactions between nanotube surfaces and the acetylacetone (acac) ligands used to stabilize the $TiO_2$ precursor provide an interesting alternative method for noncovalently coating the SWCNTs with a titania layer. The ultrathin titania layer on SWCNTs prevented the oxidation of functionalized SWCNTs at high temperatures, and protected against water molecule absorption.

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Noncovalent Titania Wrapping of Single-Walled Carbon Nanotubes for Environmentally Stable Transparent Conductive Thin Films (환경신뢰성이 확보된 투명전도성 필름을 위한 비공유 결합에 의한 단일벽 탄소나노튜브의 $TiO_2$ 코팅)

  • Han, Joong-Tark;Kim, Jun-Suk;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.279-279
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    • 2010
  • We present a simple process for the fabrication of high performance transparent conducting films that contain single-walled carbon nanotubes (SWCNTs) noncovalently coated with an ultrathin titania layer. The hydrophobic interactions between nanotube surfaces and the acetylacetone (acac) ligands used to stabilize the $TiO_2$ precursor provide an interesting alternative method for noncovalently coating the SWCNTs with a titania layer. The ultrathin titania layer on SWCNTs prevented the oxidation of functionalized SWCNTs at high temperatures, and protected against water molecule absorption.

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