Co^(60)-γ선 조사시 Bias전압에 따른 p-MOS Capacitor의 C-V특성 변화

류부형 동국대학교 경주대학 1994 東國論集 Vol.13 No.-

In this study, the irradiation effects on the electrical properties of p-type MOS capacitors, were investigated, which were irradiated by Co^60-γ ray. The capacitance-bias voltage (C-V_g) characteristics of capacitors were measured at 1 ㎒. From the experimental results, the microscopic behavior of space charges in oxide and in silicon-silicon dioxde(Si-SiO_2) interface was discussed and it is concluded as follows ; Since the quantity of space charges increases with increasing the irradiated dose, the C-V curves are shifted to higher negative bias voltage and the C-V curves become stretch-out due to the increase of the non-uniformity of interface states. The negative shift of V_fb and V_th at a constant dose are directly proportional to the square of oxide thickness. When the positive bias(+V_brad) is applied to gate electrode during irradiation, the negative shift of C-V curves increase rapidly as the V_brad increases. With a constant dose, the saturations of the V-fb and V_th are observed. This tendancy is caused by the saturation of space charges captured in the created traps. But when the negative bias(-V_brad) is applied, the negative shift of C-V curves increases only a little because the quantity of trapped holes in the vicinity of meta-oxide interface are relatively less than that in case of positive bias. From the above results, the following conclusions are summarized that the distribution of +Q_sc in the oxide layer and the density of interface traps at Si-SiO_2 interface were strongly affected by the magnitude and polarity of V_brad.

Co^60-r선 조사에 따른 이축연신 폴리프로필렌 필름의 열자격전류 특성 변화

류부형,김민,김규백 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

In order to investigate the Co^60-γ ray irradiation effects on the thermally stimulated current(TSC) characteristics of the biaxially-oriented polypropylene (BOPP) films, TSCs on the 15㎛ thick BOPP films before and after irradiation were observed in the temterature range of -120∼120℃ and at the forming electric field of 10, 30 and 60MV/m. Two distinguished peeaks such as β peak and α peak, the former was regarded as the depolarization process of dipoles on a amorphous region and the latter was attributed the thermally excited detrapping process of the trapped ions on a crystaline region in BOPP, were observed in the TSC spectra. From the observed results, the physical properties of γ-ray irradiated BOPP that are activation energy and relaxation time of charged particles, moment of dipole and forming field dependencies on TSC characteristics were analyzed and discussed.

늦깎이 한량(閑良)의 활쏘기 (1) - 나의 국궁 입문기

류부형 대한전기학회 2018 전기의 세계 Vol.67 No.4

베이즈 방법을 이용한 신규 원자력발전소 EDG신뢰도의 추정에 관한 연구

류부형,심규박 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

A commercial nuclear power plant contains at least two emergency diesel generaters(EDG) to control the risk of severe core demage during the station blackout accidents. Therefore the reliability of the EDG's to start and load-run on demend must be maintained at a sufficiently high level. Until now, Wyckoff estimators, a simple start and load-run successful rates, were used to calculate the EDG's reliability. however, this method has been many defects in various points at a situation has not enough the operation data of EDG/ In recent, K.B. Shim et al.(1996) was proposed that Bayes estimator method is more reasonable our situation. In this paper, we will apply Wyckoff method and Bayes method to estimate the reliability of EDG at construction stage and show Bayes method are more reasonable in our situation with various sides.

Flame Retardancy and Electrical/Mechanical Properties of LDPF/EVA Blend

류부형,이청,김기엽,Ryu, Boo-Hyung,Lee, Chung,Kim, Ki-Yup The Korean Society of Safety 2008 한국안전학회지 Vol.23 No.4

In this research, magnesium hydroxide as a flame retardant agents and zinc borate as a synergist were mixed with LDPF/EVA blended samples, in order to improve their flame retardancy. We attempted to select the best mixing ratio of the LDPF/EVA blend and the optimum amount of magnesium hydroxide and zinc borate by the comparison and analysis of the flame retardancy, the electrical properties such as the volume resistivity and dielectric loss tangent, and the mechanical properties such as the tensile strength and elongation at break. Particularly, specimen which is the 6phr of zinc borate and 10phr of magnesium hydroxide 70/30phr adding to the LDPF/EVA blended samples has been most excellent in flame retardancy and electrical/mechanical properties. 본 연구에서는 저밀도 폴리에틸렌과 에털렌 비닐 아세테이트 블렌드(LDPF/EVA)의 난연성을 향상시키기 위해 난연제인 수산화 마그네슘과 난연상승보조제인 zinc borate를 첨가한 후, 난연성과 체적저항률, 유전정접, 교류 절연파괴강도 등의 전기적 특성, 인장강도 및 연신율 등의 가계적 특성을 비교 분석하여 가장 우수한 LDPF/EVA 블렌드의 혼합비 및 적절한 $Mg(OH)_2$의 zinc borate의 첨가량을 선정하고자 하였다. 혼합비 70/30phr의 LDPF/EVA 블렌드에 10phr의 $Mg(OH)_2$와 6phr 정도의 zinc borate를 첨가한 시편에서 가장 우수한 난연성 및 전기/기계적 특성을 나타내었다.

늦깎이 한량(閑良)의 활쏘기 (2)

류부형 대한전기학회 2018 전기의 세계 Vol.67 No.5

트리억제제가 첨가된 LDPE의 방사선 조사에 따른 절연특성 변화

류부형 한국안전학회 2012 한국안전학회지 Vol.27 No.2

The effectiveness of treeing resistance in low density polyethylene containing azocompounds were investigated under radiation environments. 4-(4-nitrophenylazo)-1-naphthol and 4-(4-nitrophenylazo) resorcinol were selected for treeing inhibitors. LDPE containing the additives were crosslinked with dicumyl peroxide, irradiated by Co60 -ray in the presence of air at room temperature. Treeing inception voltage, AC breakdown strength measurements were carried out for electrical insulation characteristics, thermoluminescence and gel contents were analyzed as various irradiation doses also. LDPE with treeing inhibitors showed much better insulation characteristics than pure LDPE. It is interpreted that molecular structures, polar groups and the type of radicals connected on the benzene ring of the additives affected electrical characteristics. From the results, 4-(4-nitrophenylazo) resorcinol was the most effective upon the best treeing and radiation resistance

Flame Retardancy and Electrical Characteristics of LDPE/EVA Blend Involving Mg(OH)2 and Zinc-borate

류부형,조영석,Gyu Baek Kim,Sang Ho Jung 한국전기전자재료학회 2006 Transactions on Electrical and Electronic Material Vol.7 No.6

This study shows to blend ethylene vinyl acetate(EVA) and a flame retardant agent, Mg(OH)2, and synergists, zinc borate for improving flame retardancy of low density polyethylene(LDPE). And it studied the property of flame retardancy of LDPE/EVA blend by the amount of addition through LOI and TGA, estimated the electrical characteristics such as volume resistivity and breakdown strength. The flame retardancy of LDPE/EVA blend was much improved in case of adding zinc borate with 6 phr degree, and the electrical characteristics were more or less decreased depending on increasing the amount of addition. Zinc borate used for improving the flame retardancy of LDPE/EVA blend let the added amount of a flame retardant agent, Mg(OH)2 limited, and the electrical characteristics decreased extremely by adding a good deal of Mg(OH)2.

이축연신폴리프로필렌 필름의 Co^(60)-γ선 조사에 따른 전기전도 특성 변화

류부형,우흥식 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

In order to investigate the CO60-γray irradiation effects on DC electrical conduction characteristics of the biaxially-oriented polypropylene(OPP) films, DC current on the 15㎛ thick OPP films before and after irradiation were observed in the temterature range of 25~55℃ and in the electric field of 10 ~250MV/m. The electrical conduction characteristics of OPP films were devided into the four regions having different mechanisms as the hopping, space charge limiting, Schottky emission and Fowler-Nordheim's tunneling effects with the increase of the electric field. The conduction current through the OPP film were concluded as the ohmic current on the fields below 55MV/m, the space charge limited current(SCLC) on the field range from 55 to 90MV/m, the Schottky current on the mid fields from 90 to 175MV/m and the tunneling current on the high fields above 175MV/m. The conduction current on the all regions increases in proportion to the increase of the irradiated dose and temperature, but the transition points from ohmic current to SCLC and from Schottky current to tunneling current are shifted towared a lower field as the irradiated dose and temperature increase. The crystallinity of OPP film increased with increase of the irradiated dose, which caused the boundary fields of conduction regions to shift toward a higher fields.

Polytetrafluoroethylene의 열자격전류 특성에 미치는 $^{60}Co\;{\gamma}-$선 조사효과

류부형,김기엽 한국안전학회 1998 한국안전학회지 Vol.13 No.4

The effects of $^{60}Co\;{\gamma}-Ray$ irradiation on TSC characteristics of TFE type polytetrafluoroethylene(PTFE) were investigated. The $\alpha$ peak on TSC curve of PTFE was decreased, while the $\beta$ peak was reversely increased by the increasing of $\gamma$-irradiation doses up to 80 krad(0.8 kGy). Moreover, $\alpha$ and $\beta$ peaks on TSC curve of the irradiated PTFE are changed with the increasing of the forming temperature and forming electric field. In annealing the irradiated PTFE specimens at room temperature in air, it was shown a continuous recovery of TSC characteristics with time, which is assumed the traped charge carriers are liberated from the shallow traps and undergoes a recombination process during room temperature decay.