A Study on Electrical Characteristics of Outdoor Termination with Viscosity of Insulating Oil

Jin‑Wook Choe,Seok‑Hyun Nam,Jin‑Gyu Kim 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Outdoor terminations connecting overhead transmission lines and power cables comprise a stress relief cone, which is made of silicone rubber, and insulating oil in a composite or porcelain insulator. The lower the insulating oil viscosity, the greater is its ease of injection. However, the swelling and the degree of change in the electrical properties of the silicone rubber increase with a decrease in the insulating oil viscosity. Therefore, the efect of the expected change in the electrical proper‑ ties of the silicone rubber on the outdoor termination quality should be examined before choosing the insulating oil. In this study, specimens made of insulating and semiconducting silicone rubber were made to swell by impregnating them with three types of insulating oils with diferent viscosities. The AC breakdown strength of the swollen insulating specimens and the volume resistivity and relative permittivity of the semiconducting specimens were measured. The Weibull statistical analysis showed that the lower the insulating oil viscosity, the lower was the AC breakdown strength in overlapping con‑ fdence intervals. The volume resistivity and relative permittivity of the semiconducting specimens changed considerably with a change in the viscosity of the insulating oil. In particular, the volume resistivity of the specimen impregnated with the lowest viscosity insulating oil was 1.57×106 Ω m, indicating loss of semiconducting properties. Furthermore, the efect of changes in the electrical characteristics of the specimens on the outdoor termination quality was examined by performing an electric feld analysis. Compared with the other oils, impregnation with the lowest viscosity insulating oil resulted in the electric feld strength at the edge of the outer semiconducting layer increasing by 15.7%.

Escherichia coli 패혈증 환자에 합병된 대칭적 하지 말단 괴사증 1예

남해성,유진홍,권순석,민준기,조현선,박민경,심병주,남유정,이지인,김진수,길욱현,조근종,신완식 대한감염학회 2005 감염과 화학요법 Vol.37 No.6

We have encountered a rare case of symmetrical peripheral gangrene complicating Escherichia coli sepsis in a 47-years-old male. He was successfully treated with antibiotics, anticoagulants, and vasodilator. To our knowledge, this is the first report on symmetrical peripheral gangrene complicating E. coli sepsis in Korea.

Differential Manifestation of Ocular Phenotypes in TALEN-mediated p19arf Knockout FVB/N and C57BL/6J mouse lines

Jin‑Sung Park,Joo‑Il Kim,Hyun‑Jin Lim,Soo‑Kyung Ryu,Euna Kwon,Kang‑Min Han,Ki‑Taek Nam,Han‑Woong Lee,Byeong‑Cheol Kang 한국유전학회 2020 Genes & Genomics Vol.42 No.9

Background p19arf, primarily known as a tumor suppressor, has also been reported to play an essential role in normal development of mouse eyes. Consistently, lack of p19arf has been associated with ocular defects, but the mixed background of the knockout (KO) mouse strain used raised a concern on the accuracy of the phenotypes observed in association with the targeted gene due to genetic heterogeneity. Object We carried out a study to investigate into the efect of genetic background on the manifestation of p19arf KO associated phenotypes. Methods We characterized the phenotypes of novel p19arf KO mouse lines generated in FVB/N and C57BL/6J using a transcription activator-like efector nuclease (TALEN) system in comparison to the reported phenotypes of three other p19arf-defcient mouse lines generated using homologous recombination. Results Ninety-fve percent of FVB/N-p19arf KO mice showed ocular opacity from week 4 after birth which worsened rapidly until week 6, while such abnormality was absent in C57BL/6J-p19arf KO mice up to the age of 26 weeks. Histopathological analysis revealed retrolental masses and dysplasia in the retinal layer in FVB/N-p19arf KO mice from week 4. Besides these, both strains developed normally from birth to week 26 without increased tumorigenesis except for a subcutaneous tumor found in a C57BL/6J-p19arf KO mouse. Conclusion Our fndings demonstrated surprisingly variable manifestation of p19arf-linked phenotypes between FVB/N and C57BL/6J mice, and furthermore between our mouse lines and the established lines, indicating a critical impact of genetic background on functional study of genes using gene targeting strategies in mice.

Methylation Status and Expression of E-cadherin in Oral Squamous Cell Carcinomas Compared to Benign Oral Epithelial Lesions

Son, Hyun-Jin,Chu, Jung-Youb,Cho, Eui-Sic,Lee, Dong-Geun,Min, Myung-Gee,Lee, Suk-Keun,Cho, Nam-Pyo The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Expression of invasion/metastasis suppressor, E-cadherin, is reduced in many types of human carcinomas. Although somatic and germline utations in the CDH1, which encodes the human E-cadherin, have frequently been reported in cases with diffuse gastric and lobular breast ancers, irreversible genetic inactivations are rare in other human carcinomas. Recently, it has been well documented that some genes in human cancers may be inactivated by altered CpG methylation. Herein, we determined the expression and methylation status of E-cadherin in oral squamous cell carcinoma (SCC) by immunohistochemistry and methylation-specific PCR. The expression of E-cadherin was significantly higher in the well-differentiated oral SCCs than the moderately or poorly differentiated ones. None of eight tested benign pithelial hyperplasias showed aberrant methylation, whereas five of 12 oral squamous cell carcinomas showed aberrant methylation. When we compared E-cadherin expression with methylation status, oral SCCs with normal methylation showed a higher expression of E-cadherin than those with methylation. These findings suggest that aberrant CpG methylation of CDH1 promoter region is closely associated with transcriptional inactivation and might be involved in tumor progression of the oral mucosa.

외과적 노출술을 이용한 매복된 하악 제 1 대구치의 자발적 맹출 유도

김은정,김난진,조호진,김현정,김영진,남순현 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.4

하악 제 1대구치 매복의 발생 빈도는 전체 인구의 0.01%로 드물게 나타난다. 매복의 원인으로는 맹출 공간의 부족, 과잉치, 치성 종양이나 낭과 같은 맹출로상의 장애물, 유전적 요인, 내분비 질환, 외상 등이 있다. 하악 제 1대구치의 매복으로 인해 하안면 고경의 감소, 낭의 형성, 치관 주위염, 인접치의 치근 흡수, 부정 교합 등의 부작용이 생길 수 있으며, 치료 방법으로는 외과적 노출술, 교정적 견인, 외과적 재위치술, 발거 등이 있다. 다음의 두 증례는 하악 제 1대구치의 미맹출을 주소로 내원한 환아에게 외과적 노출술을 시행하여 원심 경사 매복된 하악 제 1대구치의 자발적 맹출을 유도한 증례들이다. Impaction of mandibular first molar is relatively rare and its overall frequency has been reported to be 0.01%. The etiology of impaction are lack of eruption space, physical obstacles such as supernumerary teeth, odontomas or odontogenic tumors, hereditary factors, functional disturbances of endocrine glands and traumas. Impaction of mandibular first molar can result in a short lower facial height, formation of a follicular cyst, pericoronal inflammation, resorption of the roots of neighboring teeth and malocclusion. The treatment options available for impacted teeth include surgical exposure, orthodontic forced eruption, surgical repositioning and surgical removal of unerupted molar. This report presents two cases of distally tilted and impacted mandibular first molars which were treated by surgical exposure. In these cases, we could observe spontaneous eruption of the impacted mandibular first molars after surgical exposure.

급성 관동맥증후군 환자의 신기능 이상과 주요 심장사건과의 관계

이상재,윤경호,최준호,송미진,김연경,박은미,김현정,이은미,유남진,김남호,오석규,정진원 圓光大學校 醫科學硏究所 2006 圓光醫科學 Vol.21 No.1

유자차 부산물을 이용한 유자 과편의 최적화 연구

남혜원,현영희,변진원 동아시아식생활학회 2004 동아시아식생활학회지 Vol.14 No.6

This study was performed to develop a standardized recipe for yuza pyun made of citron juice that is by-product of citron tea, to increase the utilization of citron. The effects of mungbean starch(15%, 18%) and dilution ratio of yuza extract(100%, 75%, 50%) on the quality characteristics were evaluated. The quality characteristics of the samples were estimated in terms of sweetness, color difference, texture profile analysis and sensory evaluation. Sweetness of the 18% mungbean groups were higher than 15% groups(p<0.001). The values of Hunter color system indicated that higher content of yuza extract tended to increase yellowness significantly(p<0.001). Texture profiles of hardness, adhesiveness, springiness, cohesiveness, gumminess of yuzapyun showed no significant differences among samples. For sensory evaluation, color and sourness were decreased as yuza extract was diluted, whereas elasticity and sweetness were increased. Yuza pyun containing 18% of mungbean starch with 50% diluted extract was the most preferred in overall acceptability. According to multiple regression analysis, color, sweetness, elasticity and sourness(in order) were important control factors in overall acceptability.

여천공단지역의 유해 대기 오염물질에 대한 확률론적 위해도 분석

남병현,윤미정,이진홍 忠南大學校 環境問題硏究所 1998 環境硏究 Vol.16 No.-

The study centers on a probabilistic risk assessment for the inhalation of volatile organic compounds(VOCs) and toxic metals in Yeochon industrial complex. From the assessment, the 50th∼95th percentile cancer risks by VOCs for men and women are estimated to be ??∼??, ??∼??, respectively. Those percentile risks are higher than a de minimis risk of even ??. About 4% and 1% of the 95th and 50th percentile risks for both men and women come from the only human carcinogen, benzene, while about 85% and 96% come from a probable human carcinogen, 1,3-butadiene. The 50th∼95th percentile cancer risks by toxic metals for men and women are estimated to be ??∼ ??, ??∼??, respectively. Even 95th percentile risk is lower than a de minimis risk of 10-4. About 5% and 1% of the 95th and 50th percentile risks by VOCs and toxic metals for both men and women are due to heavy metals, respectively. A comparison of the probabilistic risk estimates with point risk estimate shows that the probabilistic analysis can provide a more complete assessment of risk and more useful information to risk manager and the public. However, uncertainty remains and improved Korean probabilistic density functions(PDF) are needed for factors such as airborne concentrations, inhalation rate, exposure frequencies, and cancer potency factors.

비산회재로부터 합성된 제올라이트를 이용한 Polypropylene 촉매열분해에 관한 연구

남윤미,이진홍,김성수,정수현 한국공업화학회 2003 응용화학 Vol.7 No.1

Zeolites were synthesized from fly ash and used as catalysts for pyrolysis of polypropylene(PP) Zeolite synthesis was carried out by fusion methods employing three different NaOH/Fly ash rations in weight The catalytic performance of the fly ash-derived zeolite pyrolysis products. The properties of the fly ash-derived zeolites were characterized by XRD, SEM, BET, NH_3-TPD. It was found that the optimum NaOH/fly ash weight ratio was 1.2 in terms of the simulated boiling point distribution. The catalytic perfomance of the fly ash-derived zeolite was significantly improved by ion exchanging of zeolite from Na from(FAZ) to H from(HFAZ) The boiling point distributions of liquid pyrolysis products obtained over HFAZ were significantly lower than that obtained zeolite.

외상 후 근관내로의 치조골 함입

임예진,김영진,김현정,남순현 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

영구치의 외상성 손상은 전체 외상 환자 중 높은 빈도로 발생하며 사고의 대부분은 치근이 미완성되어 있는 시기에 발생하 여 치수, 치주인대, 치조골, Hertwig 상피 근초(HERS)에 다양한 영향을 주게 된다. 손상 정도에 따라 치수의 완전한 재혈관 화, 근관 석회화, 근관내 치조골 함입 등의 다양한 치유 양상을 나타내며, 치근단의 성장 정지 및 치수 괴사로 인한 염증성 치 근 흡수 등의 합병증을 나타낼 수 있다. 본 증례에서는 미성숙 영구치 치근단을 가진 세 환아에서 외상에 의한 Hertwig 상피 근초의 손상으로 발치와 기저부에 존 재하는 치근막 세포와 골세포의 치수강내로의 증식으로 인해 치근 발육 정지 및 근관내로의 치조골 함입을 나타내어 보고하 고자 한다. 외상 후 Hertwig 상피 근초의 손상에 의한 근관내로의 치조골 함입 치유 양상은 치수는 정상적인 기능을 하는 것으로 생각 되며, 유착 등의 합병증이 동반되지 않는 경우 특별한 치료를 필요로 하지 않으므로 감별 진단이 요구되며, 외상 받은 치아의 치료시 Hertwig 상피 근초에 대한 부가적인 외상을 가하지 않도록 주의해야 한다. Traumatic injury on tooth occurs frequently among trauma patients, and mainly occurs on tooth with premature roots which influences pulp tissue, periodontal ligament, alveolar bone, and Hertwig’s epithelial root sheath. According to the degree of trauma, a number of kinds of healing process can be observed, such as complete re-vascularization of pulp, root canal obliteration, growth suspension of root apex, and invasion of alveolar bone into root canal, and there can be some complications such as necrotic change of inflammatory root resorption and partial pulp necrosis due to pulp necrosis toward complete necrosis. In this clinical case, 3 patients who had traumatic injury showed root growth suspension and alveolar bone invasion into root canal due to proliferation of periodontal ligament cell and osteocyte at the base of extraction socket into pulp chamber because of the injury on Hertwig’s epithelial root sheath. If intrusion of alveolar bone into root canal due to injury on Hertwig’s epithelial root sheath after having traumatic injury doesn’t show any complication, the pulp may be considered to have normal vitality and doesn’t need any further treatment, therefore differential diagnosis is very necessary. However, it may be accompanied with suspension of root growth, therefore, additional trauma during the treatment of injured tooth should not be applied.