케이블 접속재 부분방전 특성에 미치는 보이드의 영향

신종열,홍진웅 한국안전학회 2003 한국안전학회지 Vol.18 No.3

To investigate the partial discharge and electric field distribution in cable joint parts, we measured the partial discharge and electric field in specimen. The specimens which cross- linked polyethylene (XLPE) and ethylene propylene diene ethylene(EPDM) are used to insulating material for underground cable and cable jointing parts. The polymers are used to insulating material in switchgear which is a kind of transformer equipment and in ultra-high voltage cable. Its using is increasing gradually, the electrical insulation properties are not only excellent, but also mechanical property is excellent. And because it is possible to be made void of several type in insulator while it is produced, which the electrical field distribution is changed by void, it has a critical influence to insulator performance. The underground cable is connecting by the jointing material, insulating breakdown and the electric ageing which are caused by several mixing impurity and the damage of cable insulator layer, which reduced the life of cable while intermediate joint kit is connected. Therefore, the computer simulation is used to estimating insulator performance, XLPE is used to the insulating material of ultra-high voltage cable and EPDM is used to insulator layer in joint material kit, and which are produced as specimen. And it is analyzed the electric field concentrating distribution and partial discharge by modeling of computer simulation in void and cable joint kit.

고차구조 변화에 따른 저밀도폴리에틸렌 박막의 전기적 특성

신종열,신현택,이수원,홍진웅 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

The electrical properties of polyethylene are changed by the superstructure. Such crystalline polymer as polyethylene or polypropylene changes crystallinity and products spherulite or trans-crystal when it is cooled slowly. In this study, after thermal treatment of LDPE at 100[℃], in silicone oil for an hour, we made specimens in order of slow cooling, water cooling, quenching according to cooling speed. Also, to study the influence of electrical properties due to the superstructure change, we analyzed physical properties and performed dielectric breakdown experiments using DC and impulse voltage. Moreover we measured space charges in bulk using Laser Induced Pressure Pulse(LIPP)method. Trap level of specimen is 0.064[eV] at the low temperature region, 0.31[eV] at the high temperature region in DC dielectric strength, 0.03[eV] at the low temperature region 0.0925[eV] at the high temperature region in impulse dielectric strength. As its result shows that the quantity of charges induced from the electrode surface increases with applied voltage time, and the distribution of space charges in samples increases the quantity of charges in proportion to applied voltage.

우울성 가성치매

박종한,오신열,권영재 大韓神經精神醫學會 1987 신경정신의학 Vol.26 No.3

Seven patients with depressive pseudodementia (4 males and 3 females) were reviewed. Their age ranged from 34 to 73 in year, with no specific preponderance. Development of pseudodementia seems to be related to major depression, either with psychotic features or with melancholia, rather than to the depressed state of bipolar disorder. Important cognitive dysfunctions were in short-term and recent memory, orientation for time, and concentration. Electroconvulsive treatment resulted in favorable outcome even in resistant patients to pharmacotherapy. Dexamethasone suppression test is not thought as valuable in the diagnosis of depressive pseudodementia.

광도와 온도가 가시광선 중합형 치과용 레진의 중합에 주는 영향

이종근,최주열,임범순,신현철 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.4

본 연구에서는 2종의 다이메타크릴레이트 치과용 레진 (urethane dimethacylate, UDMA와 bisphenol A glycerolate dimethacylate, Bis-GMA)이 광중합 반응하는 과정에서 변화되는 물성을 동역학분석법 (dynamic mechanical analysis, DMA)으로 관찰하였다. 광중합에 사용한 가시광선 (λ=400-500 nm)의 광도는 20 mW/㎠에서 70, 120, 300 및 600 mW/㎠로 변화시켜 그에 따른 저장탄성율 (storage modulus, G')과 손실탄성율 (loss modulus, G")의 변화를 측정하였고, 측정온도도 25 ℃에서 37, 50 및 60 ℃로 변화시켜 온도가 중합과정에 주는 영향을 관찰하였다. 광조사 시간은 모든 시편에 대하여 측정 시작 직후 30초로 일정하게 하였다. 각 조건에서 측정한 G' 과 tan δ (=G"/G') 결과를 이용하여 겔화 (gelation)와 유리화 (vitrification) 전이시점 (transition point)을 결정하였으며, 이를 이용하여 TTIT (Time-Temperature-Intensity-Transformation) 중합 도표를 작성하였다. 이 중합도표를 보면 광도 변화가 온도 변화보다 중합반응에 더 민감하게 영향을 주었으며, 특히 광도는 겔화보다 유리화에 훨씬 크게 영향을 주는 것을 알 수 있었다.

혈액투석 환자에서 대퇴신경범증으로 발현된 장골근 및 요근 농양 1예

이준상,강동구,신상열,윤재호,조영일,고성은,유영범,전혜정,진춘조,송종오 대한신장학회 2004 대한신장학회잡지 Vol.23 No.1

야뇨증 환아들의 심리사회적 특성에 대한 다기관 연구 : 행동 및 정서 문제를 중심으로

조수철,김재원,신민섭,황준원,한상원,박관현,이상돈,김경도,김건석,서홍진,이유식,정재용,김영균,문두건,남궁미경,한창희,조원열,김영식,배기수,이종국,정우영,신의진 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.6

Objectives : The aim of this study was to examine the behavioral and emotional problems associated with nocturnal enuresis in Korean children. Methods : Three hundred eighteen children with nocturnal enuresis, together with their parents, completed the Child Behavior Checklist (CBCL), Disruptive Behavior Disorder Scale according to DSM-IV (DBDS), Children's Depression Inventory (CDI), State-Trait Anxiety Inventory for Children (STAIC), and Piers-Harris Children's Self-Concept Scale (PHCSC). Ninety-three normal students were selected as the control group. Results : Compared to the normal control group, the mean scores with regard to the withdrawn, social problems, attention problems, delinquent behavior, aggressive behavior, externalizing problems and total problems profiles were significantly higher in the nocturnal enuresis group according to the CBCL results. The nocturnal enuresis group also scored significantly higher in the ADHD and ODD profiles of the DBDS. The nocturnal enuresis group was more depressed and anxious than the control group according to the results of the CDI and STAI. The mean score of the PHCSC was significantly lower in the nocturnal enuresis group when compared to the normal control group. Conclusion : The results of this study suggest that children with nocturnal enuresis in Korea have clinically relevant behavioral and emotional problems. The findings support the link between nocturnal enuresis and psychopathology in Korean children.

방사선 조사 마우스에서 소장움세포의 Apoptosis 발생에 미치는 생약의 효과

김성호,안미라,나승렬,이종환,김재하,조성기,장종식,신동호 대한방사선 방어학회 2001 방사선방어학회지 Vol.26 No.1

Apoptosis의 유발을 억제하는 한약제를 파악하여 apoptosis와 관련된 정상적 또는 질병에 대한 연구에 자료를 제공하고자 방사선에 의해 유도된 apoptosis를 지표로 한의학적 처방에서 많이 사용되는 대표적 한약제(24종)의 효과를 검증하였다. 용안육, 산조인, 원지, 인삼, 복령, 목향, 천궁, 백작약, 승마, 시호 및 눈꽃동충하초 투여군에서 apoptosis는 감소되었으며, 이들 생약제는 apoptosis와 관련된 질병의 예방 및 치료에 적용할 수 있을 것이다. 추 후 이들 생약의 작용 기전에 대한 연구가 요구된다. This study was performed to determine the effect of several herbs on radiation-induced apoptosis in jejunal crypt cells. Longyanrou(Euphoris longana), Suanzaoren(Zizyphus vulgaris), Yuanzhi(Polygala tenuifolia), Rensan(Panax ginseng), Fuling(Poria cocos), Muxiang(Saussurea lappa), Chuanxiong(Cnidium officinale), Baishaoyao(Paeonia lactifolia), Shengma(Cimicifuga heracleifolia), Chaihu(Bupleurum falcatum) and Dongchongxiacao(Paecilomyces japonica) reduced the frequency of radiation-induced apoptosis(p<0.05). Although the mechanisms of this effect remain to be elucidated, these results indicated that Longyanrou, Suanzaoren, Yuanzhi, Rensan, Fuling, Muxiang, Chuanxiong, Baishaoyao, Shengma, Chaihu and Dongchongxiacao might be useful inhibitors of apoptosis, especially since these are relative nontoxic natural products.

Electrical Properties of the Epoxy Nano-composites according to Additive

Shin, Jong-Yeol,Park, Hee-Doo,Choi, Kwang-Jin,Lee, Kang-Won,Lee, Jong-Yong,Hong, Jin-Woong The Korean Institute of Electrical and Electronic 2009 Transactions on Electrical and Electronic Material Vol.10 No.3

The use of a filler material in epoxy composite materials is an essential condition for reducing the unit cost of production and reinforcing mechanical strength. However, the dielectric strength of insulators decreases rapidly due to interactions between the epoxy resin and filler particles. In contrast to existing composite materials, nano-composite materials have superior dielectric strength, mechanical strength, and enduring chemical properties due to an increase in the bond strength of the polymer and nano material, It is reported that nano-fillers provide new characteristics different from the properties of the polymer material. This study is to improve the insulation capability of epoxy resins used in the insulation of a power transformer apparatus and many electronic devices mold. To accomplish this, the additional amount of nano-$SiO_2$ to epoxy resin was changed and the epoxy/$SiO_2$ nano composite materials were made, and the fundamental electrical properties were investigated using a physical properties and an analysis breakdown test. Using allowable breakdown probability, the optimum breakdown strength for designing an electrical apparatus was determined. The results found that the electrical characteristics of the nano-$SiO_2$ content specimens were superior to the virgin specimens. The 0.4 wt% specimens showed the highest electrical properties among the specimens examined with an allowable breakdown probability of 20 %, which indicates stable breakdown strength in insulating machinery design.

Dependence of the Partial Discharge Characteristics of Ultra-high Voltage Cable Insulators on the Measuring Temperature

Shin, Jong-Yeol,Park, Hee-Doo,Lee, Hyuk-Jin,Lee, Kang-Won,Kim, Won-Jong,Hong, Jin-Woong The Korean Institute of Electrical and Electronic 2008 Transactions on Electrical and Electronic Material Vol.9 No.5

Cross linked polyethylene (XLPE) insulators are used as insulation in ultra-high voltage electric power cables. This study investigated the electrical properties of XLPE at different temperatures. The electrical properties of the changing tree phenomenon was examined as a function of temperature applied to the electrical conductors by measuring the partial discharge at $25^{\circ}C$ to $80^{\circ}C$ and applied voltages to the electrodes ranging from 1 kV to 40 kV. The activity of the partial discharge was examined at various temperatures using the K-means distribution. The results revealed the specimen at $80^{\circ}C$ to have the lowest inception voltage and breakdown voltage. In addition, the core of clusters was moved $0^{\circ}$ and $180^{\circ}$ at the positive region and $180^{\circ}$ and $360^{\circ}$ in the negative region in the K-means. The distribution of clusters was concentrated on the inception condition and spread out widely at the breakdown voltage.

Performance of Three-Layered Organic Light-Emitting Diodes Using the Hole-Transport and Injection Layer of TPD and Teflon-AF, and the Electron-Injection Layer of Li₂CO₃ and LiF

Shin, Jong Yeol,Kim, Tae Wan,Kim, Gwi Yeol,Lee, Su Min,Hong, Jin Woong The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.2

The performance of three-layered organic light-emitting diodes (OLEDs) was investigated using TPD hole-transport and injection layers, Teflon-AF, and the electron-injection layer of $Li_2CO_3$ and LiF. The OLEDs were manufactured in a structure of TPD/$Alq_3$/LiF, TPD/$Alq_3$/$Li_2CO_3$, and AF/$Alq_3$/LiF using low-molecular organic materials. In three different three-layered OLEDs, it was found that the device with the TPD/$Alq_3$/LiF structure shows higher performance in maximum luminance, and maximum external quantum efficiency compared to those of the device with TPD/$Alq_3$/$Li_2CO_3$ and TPD/$Alq_3$/LiF by 35% and 17%, and 193% and 133%, respectively. It is thought that the combined LiF/Al cathode contributes to a reduced work function and improves an electrical conduction mechanism due to the electron injection rather than the hole transport, which then increases a recombination rate of charge carriers.