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%.

조혈모세포이식 환자에서 침습성 진균 감염에 대한 Micafungin의 예방 효과 및 안전성

김시현,이동건,최수미,권재철,박선희,최정현,유진홍,이성은,조병식,김유진,이석,김희제,민창기,조석구,김동욱,이종욱,민우성,박종원 대한감염학회 2010 감염과 화학요법 Vol.42 No.3

Background: Micafungin, a potent inhibitor of 1,3-β-D-glucan synthase, is a novel antifungal agent of the echinocandin class. In vitro study showed that micafungin was effective against Aspergillus species as well as Candida species, but clinical data on the prophylactic efficacy against invasive fungal infections (IFIs) other than candidiasis are still lacking. Materials and Methods: We identified 60 consecutive adult hematopoietic stem cell transplantation (HSCT) recipients who received at least 3 doses of micafungin during neutropenic period. Micafungin was started as an alternative in patients who were intolerant or had adverse events (AEs) to primary prophylactic antifungal agents. We retrospectively reviewed the medical records and analyzed the efficacy and safety of micafungin for prophylaxis against IFIs. Results: The patients either had autologous (n=9) or allogeneic (n=51: 1 syngeneic, 24 sibling, 26 unrelated donor) HSCT. Itraconazole oral solution (n=58) was the most frequently used first line antifungal agent for prophylaxis and was administered for median 11 days. The most frequent cause of switch to micafungin was vomiting (n=42). The duration of neutropenia and micafungin administration was median 13 and 12 days, respectively. A successful outcome was achieved in 45 (75%) patients. Empirical antifungal therapy was initiated in 13 (22%) patients. There were 2 cases (3.3%) of breakthrough fungal infections which comprised a probable invasive pulmonary aspergillosis and a possible invasive fungal sinusitis. There was no case of invasive candidiasis. A total of 53 (88%) patients experienced at least one AE regardless of causality during micafungin administration. The most frequent AEs were hypokalemia, vomiting, diarrhea, and elevated serum aspartate aminotransferase or alanine aminotransferase. Among the aforementioned AEs, only 1 case of diarrhea could be classified as a probable relation with micafungin when causality was assessed. There was no AEs that caused discontinuation of micafungin. Conclusions: Micafungin seems to be a safe and effective agent for prophylaxis of IFIs including aspergillosis as well as candidiasis in HSCT recipients. However, further large, prospective, and randomized comparative studies are warranted for aspergillosis.

지역사회 연계를 고려한 진주종합경기장 활용방안 연구

강석진(Kang, Seok-Jin),안재우(Ahn, Jae-Woo),김지희(Kim, Ji-Hee),이현진(Lee, Hyun-Jin) 대한건축학회 2013 대한건축학회 학술발표대회 논문집 Vol.33 No.2

경막 내 colistimethate 투여로 치료한 다제 내성 cinetobacter baumannii 뇌실염

홍유아,유진홍,김진진,모은영,안건희,정희경,김진석,이현정,정미향,윤승배 대한감염학회 2009 감염과 화학요법 Vol.41 No.4

Acinetobacter species is a non-fermentative aerobic gram-negative coccobacillus that is an important pathogen found in nosocomial infections. Recently, multi-drug resistant Acinetobacter baumannii (MDR-AB) infections have been increasing and pose a serious problem. Most such infections present as bacteremia, pneumonia, or a wound infection; however, CNS infections are very rare. We herein present a case of ventriculitis caused by MDR-AB in a 37-year old man after a neurosurgical intervention. The patient was successfully treated with intrathecal colistimethate.

고성능 표면탄성파 필터의 최적 설계에 관한 연구

신양호,김귀현,이진복,엄현석,이중근,박진석 漢陽大學校 工學技術硏究所 1999 工學技術論文集 Vol.8 No.1

본 논문에서는 고성능 표면탄성파 필터의 최적 설계를 위하여 다양한 IDT(interdigital transducer) 구조의 필터를 제작하고 각각의 주파수 응답특성을 비교 분석하였다. 기본 구조외에 MSC(micro strip-coupler), double split, reflector, ground line 등의 구조를 일반적으로 널리 사용되고 있는 Y-Z cut l-N(LiNbO3) 기판 위에 형성시켰다. 제작된 소자의 중심주파수, 통과 대역, 삽입손실등을 측정하였으며, 주파수 응답에 기초한 기존 모델의 효용성을 논의하였다. Effects of IDT structures on frequency responses of SAW filters are investigated to achieve a high performance SAW filter, Various types of IDTS, such as MSC(multistrip-coupler), double split, reflector, and ground line, are designed and patterned on a widely used Y-Z cut LN(LiNbO3) substrate. Center frequencies, band widths, and insertion losses are measured and compared. Invalidity of the conventional model based on the impulse response model is also discussed.

수 종의 복합레진 접착 시스템에서의 미세 누출의 비교

석충기,남동우,남순현,김영진,김현정 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.4

최근 자가 부식형 접착 시스템이 개발되어 법랑질 및 상아질에 모두 적용할 수 있고, 임상적 술식을 단순화 시켰다. 이 접착 시스템은 적용하기 용이하고 임상적으로도 법랑질 및 상아질에 높은 결합강도를 보인다고 보고되고 있다. 이 연구는 in vitro 상에서 복합레진 5급 와동의 법랑질 및 상아질 경계에서 전부식 처리를 동반한 one-bottle 접착시스템과 자가 부식형 접착 시스템을 사용하였을 때 미세 누출을 비교하기 위해 시행하였다. 교정적 목적으로 발치된 30개의 소구치를 무작위적으로 3개 군으로 나누었다; 1 군 (Single Bond^(�) + Filtek Z250^(�)), 2 군 (Clearfil SE Bond^(�) + Filtek Z250^(�)), 3 군 (Adper Prompt L-Pop^(�) + Filtek Z250^(�)). 표준화된 5급 와동을 각 소구치 협면, 설면에서 백악-법랑경계에 평행하게 형성하였으며, 와동의 치은측 1/2은 백악-법랑경계보다 1mm 치근단으로 연장하였다. 접착 시스템을 제조자의 지시대로 적용한 다음 복합레진을 충전하고 제조자의 지시대로 광중합하였다. 시편을 37℃ 증류수에 5일 간 보관 후 5℃±2℃ 와 55℃±2℃에서 1000회 열순환한 다음, 2% methylene blue 용액에 12시간 침잠시켰다. Isomet^(TM) (Buehler Co., Lake Bluff, IL, USA)을 사용하여 치아를 충전물 중앙에서 종절단한 후 입체 현미경하에서 25배의 배율로 색소 침투도를 평가하였다. 결과는 t-test 와 one-way ANOVA를 이용하여 통계처리 하였다. 결과는 다음과 같았다. ·실험에 사용 된 접착 시스템 중에 미세 누출을 완벽하게 방지하는 접착 시스템은 없었다. ·상아질 경계에서의 미세 누출이 법랑질 경계에서보다 통계학적으로 유의하게 더 많았다(p<0.0001). ·법랑질 경계에서 자가 부식형 접착 시스템은 전부식 처리를 동반한 one-bottle 접착 시스템과 통계학적으로 유의한 차이를 보이지 않았다. ·상아질 경계에서, 자가 부식형 접착 시스템은 전부식 처리를 동반한 one-bottle 접착 시스템과 통계학적으로 유의한 차이를 보이지 않았다. Recently, self-etching adhesive system have been developed and bonding procedures simplified into one or two steps, which are simultaneously applied to both enamel and dentin. These systems are easy to use and have the potential for good clinical success. The purpose of this study is to evaluate in vitro the microleakage on the cementum/dentin and enamel walls in composite resin restoration of Class V cavities, regarding the use of different adhesive systems. 30 human premolars were divided into 3 groups. A standardized Class Ⅴ preparation was prepared on the buccal and lingual surface of each premolar. The preparation were made parallel to the cementoenamel junctions, with the gingival half of the preparation extending 1mm apical to the cementoenamel junction. After adhesive system was applied to teeth as manufacture's recommendation, hybrid resin composite was filled in bulk into the preparation and light polymerized according to manufacturer's recommendations. Specimen were stored in distilled water at 37℃ for 5 days and thermocycled 1000 times (5℃+2℃ and 55℃±2℃), then immersed in a 2% methylene blue solution for 12 hours. After sectioning mesio distally through the restorations, the degree of dye penetration was scored under a stereomicroscope at × 25 magnification. The data were analyzed statistically using t-test and one-way ANOVA. The results were as follows: · There is no adhesive system which can prevent microleakage perfectly. · There is significant difference in microleakage between enamel margin and dentin margin (p<0.0001). · In enamel margin, self-etching primer systems did not show any significant difference comparing total-etching system. · In denin margin, self-etching primer systems did not show any significant difference comparing one-bottle adhesive system used in combination with total-etching.

Conceptual Study for Tissue-Regenerative Biodegradable Magnesium Implant Integrated with Nitric Oxide-Releasing Nanofi bers

Jin‑Kyung Jeon,Hyunseon Seo,Jimin Park,Soo Ji Son,Yeong Rim Kim,Eun Shil Kim,Jong Woong Park,Woong‑Gyo Jung,Hojeong Jeon,Yu‑Chan Kim,Hyun‑Kwang Seok,Jae Ho Shin,Myoung‑Ryul Ok 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The excessive initial corrosion rate of Mg is a critical limitation in the clinical application of biodegradable Mg implantsbecause the device loses its fi xation strength before the fractured bone heals. This study suggests a new approach to overcomethis hurdle by accelerating tissue regeneration instead of delaying the implant biodegradation. As angiogenesis is anessential process in early bone regeneration, a Mg implant coated with electrospun nanofi bers containing nitric oxide (NO),which physiologically promotes angiogenesis, is designed. The integrated device enables adjustable amounts of NO to bestored on the NO donor-conjugated nanofi ber coating, stably delivered, and released to the fractured bone tissue near theimplanted sites. An in vitro corrosion test reveals no adverse eff ect of the released NO on the corrosion behavior of the Mgimplant. Simultaneously, the optimal concentration level of NO released from the implant signifi cantly enhances tube networkformation of human umbilical vein endothelial cells without any cytotoxicity problem. This indicates that angiogenesis canbe accelerated by combining NO-releasing nanofi bers with a Mg implant. With its proven feasibility, the proposed approachcould be a novel solution for the initial stability problem of biodegradable Mg implants, leading to successful bone fi xation.

맹출 장애를 가진 상악 제1대구치의 외과적 노출을 이용한 치험례

석충기,남동우,김현정,김영진,남순현 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.1

치아의 맹출이란 구강내로 치아가 출현하기 전의 악골 내에서의 이동, 구강에 출현하여 교합면에 이르기까지의 이동, 그리고 교합면 도달이후의 추가적인 이동 등 모두를 포괄적으로 의미하는 용어이다. 맹출은 대부분 유전적으로 결정되며 치아가 성장 발육 과정에 따라 구강내로 맹출되는 과정은 preeruptive alveolar bone stage, alveolar bone stage와 mucosal Stage로 구분할 수 있는데, 이들 과정의 어느 단계에서도 장애가 발생하면 치아가 맹출하지 않는다. 맹출 장애의 원인으로는 치배의 부정위, 정상 맹출로의 방해, 치낭 혹은 치주인대의 손상 등이 있다. 맹출 장애 치료에는 유치발거 및 맹출 공간확보, 외과적 노출, 외과적 정위, 외과적 노출 후 견인이 있고, 이 중 외과적 노출이 가장 기본적인 술식이다. 외과적 노출은 영구치를 둘러싸는 점막, 골, 병소, 경우에 따라 치낭 등을 제거하여 개방된 맹출로를 확보하는 것이고, 형성된 맹출로는 레진관(celluloid crown)의 접착, 거타 퍼챠 혹은 산화 아연 유지놀 시멘트, 치 주 포대 등을 노출된 부위 에 충전하여 개방성을 유지하여야 한다. 외과적 노출시에는 치경부 치근의 백악질을 노출시키지 않도록 하여야 하며, 인접치아의 치주 조직이나 치근의 손상도 피 해야 한다 또한 노출 후 치아는 각화된 치은에 위치하여야 한다. 외과적 노출 중에 가해진 손상의 정도는 치아의 병리, 생리 학적 이상의 발현에 영향을 미치므로 주의하여야 한다. 본 증례들은 상악 제1대구치가 맹출 장애를 가긴 증례들이었으며, 이를 개선하기위해 위의 사항을 고려하여 외과적 노출을 시행하였고, 맹출 장애를 효과적으로 개선할 수 있었다. The eruption of permanent teeth represents the movement in the alveolar bone before appearance in oral cavity, to the occlusal plane after appearance in oral cavity, and additive mevement after reaching th the occlusal plane. Tooth eruption is mostly controlled by genetic signals. The eruption stage is divided to preeruptive alveolar stage. alveolar bone stage, mucosal stage according to the process of growth and development. If the disturbance is occured in any stage of eruption, tooth does not erupt. The cause of eruption disturbance are eclopic position of the tooth germ, obstruction of the eruption path and defects in the follicle or PDL. In the treatment of eruption disturbance, surgical procedures are commonly used. There are three kind of surgical procedure surgical exposure, surgical repositioning, surgical exposure and traction Surgical exposure is basic procedure. This involves removal of mucosa, bone, lesion that are surrounding the teeth, dental sac when necessary to maintain a patent channel between the crown and the normal eruptive path into the oral cavity. To ensure this patency, many techniques including cementation of a celluloid crown, packing with gutta-percha or zinc oxide eugenol, or a surgical pack, are used. When surgical exposure is conducted, operators should not expose any part of cervical root cement and not in jure periodontium or root of adjunct tooth. After surgical exposure, tooth should be surrounded by keratinized gingiva. There is direct relationship between the extent of development of pathophysiologic aberrations and the intensity of the manipulative injury inflicted on the tooth by surgical treatment, so operator should consider this thing. In these cases surgical exposure is conducted on Maxillary 1st milars that have a eruption disturbance and improve the eruption disturbance effectively.

안구의 비색소성 모양체 상피에서 발생한 유두상 선암종 -1예 보고-

최현주,최영진,이연수,이은정,강석진,김병기,심상인 대한병리학회 1998 Journal of Pathology and Translational Medicine Vol.32 No.12

冷凍冷藏倉庫 前室部 侵氣防止裝置의 適用에 關한 硏究

석호태,곽현철,송승영,송진규,이영욱 대한건축학회 2003 대한건축학회논문집 Vol.19 No.4

This study aims to evaluate the economic performance of infiltration prevention devices for the refrigerated warehouse. It is showed that the cooling loads of refrigerated warehouses is changed by assembling of infiltration prevention devices in a previous study. Space loads and cooling energy costs according to the types of the infiltration prevention devices are analyzed by the DOE-2.1E simulation. Based on the Life Cycle Costs considered the costs of initial construction, repair·replace, cooling energy and operating energy, the probability of reducing energy consumption and application of infiltration prevent devices in vestibule of refrigerated warehouse is founded.