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요오드 흡착에 의한 폴리아크릴로니크릴 구조의 변화(II)
김홍성,조현혹 한국섬유공학회 1992 한국섬유공학회지 Vol.29 No.3
The structural change of polyacrylonitrile was investigated by iodine sorption in aqueous 1$_2$/KI solution. lodines could penetrate into the crystalline phase of polyacrylonitrile and disturb the laterally ordered polyacrylonitrile crystals below the low concentration of which I/M=O.33. Beyond this I/M up to 0.77, these iodine ions were found to form a linear lattice of about 3.1 A spacing like as in other systems and to orient parallel to the orientation axis in the crystalline phase of polyacrylonitrile. The 5.8A, 4.1A, and 3.9A diffraction intensities for polyacrylonitrile-iodine complex were observed on equator, which increase with increasing iodine concentration in the sorbed phase. These observed diffraction intensities and sorption-desorption behaviors suggest that the iodine which penetrates into crystalline phase intercalates between molecular rods of polyacrylonitrile without a conformational change, and forms a new ordered structure with the parent polymer.
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김홍성,조현옥 한국섬유공학회 1992 한국섬유공학회지 Vol.29 No.2
Iodine sorption of polyacrylonitrile(PAN) in aqueous I$_2$/KI solution was investigated for structural study of PAN. The sorption behaviors for uniaxially oriented film and unoriented film show a distinct difference below the concentration of O.8mole/l. The dimension of oriented film treated above this concentration recovers its original dimension. As the diffusion of iodine into PAN is the mode of non-Fickian, the diffusion coefficient increases with time of sorption. The sorption behavior in disordered region of oriented film is found to be similar to that of unoriented film. It is ascertained that iodine is able to penetrate into ordered as well as disordered region of PAN below the concentration of 0.5 mole/l.
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IEEE 929-2000 단독운전 시험조건 하에서 단상 계통연계형 PV 시스템의 Anti-Islanding을 위한 RPV 방식 및 AFD방식의 해석 및 설계
김홍성,최규하,김재철,최영호,김한구 전력전자학회 2007 전력전자학회 논문지 Vol.12 No.1
To detect islanding mode when the grid is being tripped is a major safety issue in utility interactive PV(UIPV) system. Widely used techniques among various active methods to detect islanding mode are Reactive power variation (RPV)method and Active frequency drift(AFD) method. In this paper, analytical design method is suggested for AFD and RPV method under IEEE recommended islanding test condition. And in order to show the validity of proposed method, EMTP based simulation was done for UIPV system with RPV method and AFD method. Results shows proposed method is very useful. 계통연계형 PV 시스템의 중요한 보호기능인 단독운전 검출기능은 시스템의 안전성 및 전기적 안정성 측면에서 매우 중요하다. 단독운전 검출기법으로는 크게 수동적 방식과 능동적 방식으로 분류되는 다양한 기법들이 있다. 본 연구에서는 IEEE 929-2000에서 제시하는 단독운전 시험조건 하에서 현재 널리 사용되는 능동적 방식 중 무효전력 변동 방식(RPV method)과 능동적 주파수 변동 방식(AFD method)을 채용한 시스템의 연계점에서 주파수 변동 특성을 해석하였다. 그리고 해석결과를 바탕으로 RPV 방식 및 AFD 방식의 설계법을 제시하였다. EMTP를 이용한 시스템 시뮬레이션을 통하여 제안된 해석 및 설계법의 타당성 및 유효성을 검증하였다.
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김홍성,조현혹 한국섬유공학회 1991 한국섬유공학회지 Vol.28 No.2
Structual change of untreated and salt-treated drawn polyacrylonitrile(PAN) fiber has been studied with IR spectroscopy, wide angle X-ray diffraction, dynamic mechanical measurements, thermo-mechanical analysis, and tensile propert irs measurements. The results are interpreted in terms of the degree of bound nitrile groups based on two-phase structure, ordered and disordered region. The salt treatment resulted that the crystalline size and the degree of lateral ordered crystallinity were increased. The bound nitrile groups in ordered and disordered region of salttreated PAN fiber were lower than these of untreated fiber.
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