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%.

관상동맥 스텐트 삽입술을 시행한 환자에서 안지오텐신 전환효소 억제제와 안지오텐신 수용체 차단제가 재협착에 미치는 영향

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

심근 허혈-재관류 백서 모델에서 mitogen-activated protein kinase 활성화에 대한 α-lipoic acid의 효과

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

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

수용성 키틴이 백서 창상치유에 미치는 영향

강장석,조용남,정상훈,유 결,임진수,권 호,조용우,고석원 大韓成形外科學會 2001 Archives of Plastic Surgery Vol.28 No.1

양극성장애와 새로운 항경련제의 효과

남범우,서정석,정헌종,최진영 건국대학교 의과학연구소 2004 건국의과학학술지 Vol.13 No.-

Bipolar disorder, like epilepsy and migraine, is episodic in nature and psychiatric illness requiring lifelong treatment. So, it should not be surprising that anticonvulsants such as carbamazepine and valproate have proven efficacy as mood stabilizers. The newer anticonvulsants such as lamotrigine, gabapentin, topiramate, oxcarbazepine, tiagabine, and zonisamide may also be effective treatments for bipolar disorder. Identifying an anticonvulsant for use in bipolar disorder should take into account not only the pathophysiology of bipolar disorder but also the mechanism of action of the anticonvulsant. Evidence for effectiveness of these novel antiepileptic drugs in treating acute mania and depression as well as in preventing the recurrence of mania and depression is reviewed. In conclusion, although the novel anticonvulsants appear to be clinically useful, more controlled trials are needed to assess the effectiveness in bipolar disorder.

비내시경을 이용한 안와 내벽 골절 정복 2예

김진국,남태욱,임채형,김재영,김정석 건국대학교 의과학연구소 2001 건국의과학학술지 Vol.11 No.-

Traditional surgical approaches to orbital medial wall fractures are either extraocular skin incision or indirect bicoronal flap. However these methods can leave remarkable orbital scar or scalp alopecia with possible complications. Endoscopic intranasal visualization of the medial orbital wall and lamina papyracea is a technique familar to otolaryngologists. This endoscopic view allows confirmation of fracture of medial orbital wall and herniation of orbital contents. Good visualization of the fracture can facilitate the anatomic reduction of orbital contents and the proper placement of orbital implant. Two cases of medial orbital wall fracture repaired by intranasal endoscopy using silastic sheet are reported.

Acid Phytase를 생산하는 Pseudomonas fragi의 분리와 phytase의 생산조건

김영진,장은석,인만진,오남순 한국응용생명화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.4

cnrtkscP수가 방류되는 단위동물 밀집사육장 인근의 하천수로부터 phytase를 생산하는 세균들 중 활성이 가장 우수한 균주를 분리하여 Paseudomonas fragi Y9451로 동정, 명명하였다. 탄소원으로 fructose를 첨가할 경우에 phytase의 생산능이 가장 우수하였고, 배지에 7% 첨가할 경우에 72시간 배양 후 효소활성이 1,078mU/m로 최대의 phytase생산능을 보였다. 또한, 질소원으로는 nutrient broth(NB)가 적합하였으며, NB를 3%의 농도로 첨가할 경우에 96시간 배양 후 효소활성이 1,425mU/m까지 향상되었다. 인산원인 KH₂PO₄ phytate는 첨가 농도가 높을수록 phytase생산은 억제되었으며, 무기염으로 MgSO₄와 CaCI₂를 첨가하는 경우는 첨가농도와 상관없이 phytase의 생산을 현저히 억제하였다. 산업생산을 목적으로 하는 scale-up에 있어서의 통기교반 효과는 phytase의 생산량에 큰 영향을 미치는 것으로 나타났다. A bacterial strain producing a high level of an extracellular phytase was isolated from livestock waste water, identified as a strain of Pseudomonas fragi and designated as Pseudomonas fragi Y9451. Under the phytase production medium, the activity of phytase reached the highest level after 120 hours of incubation. On the effect of carbon sources on the phytase production, the most favorable carbon source for phytase production was fructose. As for the effect of nitrogen sources, high levels of phytase activity were detected in the medium containing nutrient broth as the nitrogen source. Free PO₄^(3-) inhibited phytase production with increasing concentration of KH₂PO₄ and phytate in the media. The addition of CaCl₂ and MgSO₄ also resulted in the inhibition of phytase production. To investigate the effect of aeration on the phytase production, different volumes of culture broth Erlenmeyer flasks were incubated in rotary shaker at the speed of 200 rpm. As a result, a high level of phytase activity was detected at small volume of culture broth at compared to larger volume because of its more aerobic condition.

횡문근 융해증의 Tc-99m Methylene Diphosphonate 신티그라피 소견

한창진,박찬희,윤석남,배문선,김수지,신규설 아주대학교 1997 아주의학 Vol.2 No.2

Many causes of rhabdomyolysis have been reported in the literature. Technetium-99m methylene dipho-sphonate (Tc-99m MDP) bone scintigraphy is considered to be the most sensitive and effective modality in defining the extents of disease involvement and follow-up of patients with rhabdomyolysis. In this paper, we reviewed two cases of generalized rhabdomyolysis related to seizure activities and two cases of localized rhabdomyolysis related to an excessive exercise. In addition other causes of rhabdomyolysis and possible mechanisrns of Tc-99m MDP uptake are discussed briefly.

교정치료 시 브라켓 부착 및 제거에 따른 치아색 변화

김석필,황인남,조진형,황현식 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.2

본 연구는 교정용 브라켓 부착을 위한 레진 접착부위 및 그 인접부위 즉, primer만 도포된 부위의 색변화를 알아보기 위하여 시행되었다. 교정치료를 위해 발치된 60개의 건전한 소구치를 재료로 사용하여 분광측정기로 색을 측정한 후 CIE L*a*b* 색표계로 기록하였다. 20개의 소구치에 광중합형 접착레진으로 브라켓을 부착한 후 부착 전과 제거 후의 색을 측정하였으며 다른 20개의 소구치에는 primer만 도포하고 도포 전과 도포 후의 색을 측정한 후, L* 값을 이용하여 명암 변화를 살펴본 결과 브라켓 부착 및 primer 도포 모두의 경우 명도가 감소하는 경향을 보였으며, a* 값과 b* 값을 이용하여 색상 변화를 살펴본 결과 황색이 증가하는 양상을 나타내었다. 또한 측정된 L*a*b* 값을 이용하여 색변화를 산출하고 임상적으로 인지할 수 있는 색변화 값 3.7을 기준치로 하여 비교 및 분석을 시행한 결과 브라켓 부착 전과 제거 후의 색변화는 기준치보다 큰 것으로 나타났으며 primer 도포에 따른 색변화는 기준치보다 크지 않은 것으로 나타났다. 한편 primer만 도포한 경우 칫솔질에 따른 색변화를 알아보고자 나머지 20개의 소구치를 대조로 하여 칫솔질을 시행한 결과 칫솔질 시행 후 색변화는 기준치보다 큰 것으로 나타났다. 브라켓 제거 후 자연광 노출의 영향을 알아보기 위하여 모든 경우에 추가적으로 photoaging을 시행한 결과 부기적인 색변화는 기준치보다 작은 것으로 나타났다. 이상의 결과는 교정치료를 위한 브라켓 부착으로 인해 브라켓 부착 및 인접부위의 치아색 변화가 있음을 의미하며 임상과정에서 이에 대한 고려가 필요함을 시사하였다. The purpose of this study was to evaluate the tooth color changes of resin bonding sites and their adjacent sites on orthodontic bracket bonding. Sixty extracted sound premolars were used and the tooth color was recorded according to the CIE L*a*b* color system using a spectrophotometer. The tooth colors of the twenty premolars were measured and compared before bracket bonding and after removal. On a further twenty premolars, the tooth color was measured before and after only primer application. In the change of L* values, according to the bracket bonding and primer application, the lightness was decreased, and in the change of a* and b* values, the color was changed into a more yellowish color. The color differences (ΔE*) were calculated from the L*a*b* values and compared with the standard value of clinical detection (ΔE*=3.7). The color differences between before the bracket bonding and after removal noted exceeded the standard value and those of between before and after the primer application were not larger than the standard value. Tooth brushing was performed after application of the primer to evaluate the color changes according to the primer abrasion. As a control, toothbrushing was performed on the last twenty premolars. The color differences noted were larger than the standard value after toothbrushing. Also, to evaluate the color changes of the tooth which is exposed to sun irradiation after bracket removal, additional photoaging was performed and the color was measured for all teeth. The additional color differences after photoaging were smaller than the standard value. The above results suggest that the tooth color changes after fixed orthodontic treatment.