• Title/Summary/Keyword: light transmission

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Transmission-Line Wiring Midair Protection Net & Installation Methods (송전선로 가선용 공중설치형 방호네트 및 설치공법)

  • Hwang, Chi-Young;Back, Byoung-Chul;Seo, Min-Geun;Kim, Young-Hwa;Won, Jea-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1479-1484
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    • 2011
  • The existing leg-rest for transmission line construction was established on the ground as a structure. As a result of that, it caused some problems such as, a tremendous forest damage, excessive construction costs and the long time of construction period. In order to solve these problems, we suggest the protective net for an air installation. It is a new method of construction which has a dielectric strength with a light-weight and high-strength. And it's not influenced by a geographical feature. This excellent method doesn't affect a forest and can reduce tremendously the construction cost and period.

Surface Ageing Property of Polymer Insulator for Transmission line with Forest Fire Test (송전용 폴리머 애자의 산불 모의시험에 따른 표면열화 특성)

  • Cho, Han-Goo;Kim, Kyang-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.110-110
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    • 2010
  • Suspension insulator have made use of porcelain insulator mainly, but polymer insulator is using recently. Polymer suspension insulator have advantage that it is light than porcelain insulator. The ageing performance is excellent and it is possible for mass production. There is high possibility of mountain fire because a lot of potential inflammables such as fallen leaves are stacked on the ground Therefore surface aging of polymer insulator most of the overhead transmission lines in Korea are operated on the mountain need analysis of transmission line into forest fire. surface aging property is analyzed by SEM, EDX, XPS, FTIR, DSC in this paper.

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A Study on Fault Detecting for Underground Power Transmission Lines using Optical Field Sensors (광응용 자계센서를 이용한 지중송전선 사고구간 검출에 관한 연구)

  • Lee, Kwang-Jung;Kim, Seok-Koo;Park, Hae-Soo;Kim, Yo-Hee
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.91-93
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    • 1994
  • Recently, for improving the power supply reliability and for rationslizing maintenance, new maintenance and monitoring systems are stornagly desired for use in the field of electric power transmission. In this paper, we describes the optical fault detecting method of underground power transmission lines using bareearth doped YIG Faraday sensors which are very light, small size and fast response. As regarding, we use the zero phase current detecting algorithm at insulated joints.

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Alignment of a ring laser cavity by using the cavity transmission spectrum control method (투과광 스펙트럼 측정법을 이용한 링레이저 공진기의 광학적 정렬)

  • 전형욱;최용진;이기홍;신상훈;이혁수;손정영
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.456-460
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    • 1997
  • Several methods of aligning ring type cavities have been investigated for long time. The measurement of cavity transmission spectrum control is somewhat effective due to aligning cavity with measuring cavity loss at the same time. In this research, four mirrors are aligned and attached by the measurement of pulse width of the transmitted light. The intracavity loss is optimized to about 0.98%, giving the calculated total reflection coefficient of about 99.02%.

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Tracking Property of Polymer Suspension Insulator for Transmission line with secular variation (경년변화에 따른 송전용 폴리머 현수애자의 트래킹 성능평가)

  • Cho, Han-Goo;Lee, Un-Yong;Lee, You-Jung;Lim, Kee-Joe;Choi, In-Hyuk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.558-559
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    • 2005
  • Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. In this paper, the tracking property of polymer suspension insulator for power transmission is investigated with CEA tracking wheel test. The diagnosis of insulator sample in tracking test has been analyzed by leakage current, STRI Guide, SEM, FTIR and thermal image.

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Use of Modern Non­destructive Techniques in High Temperature Degradation of Material and Coatings

  • Lee, C.K.;Sohn, Y.H.
    • International Journal of Korean Welding Society
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    • v.3 no.2
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    • pp.29-39
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    • 2003
  • The durability and reliability of thermal barrier coatings (TBCs) play an important role in the service reliability, availability and maintainability (RAM) of hot­section components in advanced turbine engines for aero and utility applications. Photostimulated luminescence spectroscopy (PSLS) and electrochemical impedance spectroscopy (EIS) are being concurrently developed as complimentary non­destructive evaluation (NDE) techniques for quality control and life­remain assessment of TBCs. This paper overviews the governing principles and applications of the luminescence and the impedance examined in the light of residual stress, phase constituents and resistance (or capacitance) in TBC constituents including the thermally grown oxide (TGO) scale. Results from NDE by PSLS and EIS are discussed and related to the microstructural development during high temperature thermal cycling, examined by using a variety of microscopic techniques including focused ion beam (FIB) in­situ lift­out (INLO), transmission and scanning transmission electron microscopy (TEM and STEM).

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Introduction to Cathodoluminescence Spectroscopy Using Scanning Transmission Electron Microscopy (주사 투과 전자현미경을 활용한 음극형광 분석법)

  • Sung-Dae Kim
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.4
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    • pp.326-331
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    • 2023
  • The utilization of scanning transmission electron microscopy (STEM) in conjunction with cathodoluminescence (CL) has emerged as a valuable tool for the investigation of material optical properties. In recent years, this technique has facilitated significant advancements in the fields of plasmonics and quantum emitters by surpassing prior technical restrictions. The review commences by providing an outline of the diverse STEM-CL operating modes and technical aspects of the instrumentation. The review explains the fundamental physics of light production under electron beam irradiation and the physical basis for interpreting STEM-CL experiments for different types of excitations. Additionally, the review compares STEM-CL to other related techniques such as scanning electron microscope CL, photoluminescence, and electron energy-loss spectroscopy.

NIPAH Virus - "A Bane to Mankind"

  • Jaiganeshan Muttiah Velmurugan;Lakshmi Krishnasamy
    • Microbiology and Biotechnology Letters
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    • v.52 no.3
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    • pp.221-232
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    • 2024
  • Zoonotic diseases are rare but the transmission of disease to humans may cause serious illness. Nipah virus (NiV) is a bat-borne zoonotic pathogen, which can cause severe encephalitis and respiratory distress. The transmission of Nipah virus from bats to humans was first reported in Malaysia in 1998. Different strains of NiV show different epidemiological and clinical features. Few of the strains are highly lethal and can spread to the community resulting in a global threat. However, the availability of effective management or prophylactic measures are only limited. Thus, it is essential to contain such outbreaks by implementing proper infection control and surveillance measures. Many serological and molecular diagnostic techniques have been developed for diagnosis of this infection. This review mainly focuses on the epidemiology, transmission of Nipah virus, pathogenesis and management of NiV infection. The review also throws light on the immune response of NiV in humans and the role of One Health approach in prevention and control of NiV infection.

Enhancement of Light Extraction Efficiency of GaN Light Emitting Diodes Using Nanoscale Surface Corrugation (나노크기 표면 요철을 이용한 GaN LED의 광추출효율 향상)

  • Jung, Jae-Woo;Kim, Sarah;Jeong, Jun Ho;Jeong, Jong-Ryul
    • Korean Journal of Materials Research
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    • v.22 no.11
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    • pp.636-641
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    • 2012
  • In this study, we have investigated highly efficient nanoscale surface corrugated light emitting diodes (LEDs) for the enhancement of light extraction efficiency (LEE) of nitride semiconductor LEDs. Nanoscale indium tin oxide (ITO) surface corrugations are fabricated by using the conformal nanoimprint technique; it was possible to observe an enhancement of LEE for the ITO surface corrugated LEDs. By incorporating this novel method, we determined that the total output power of the surface corrugated LEDs were enhanced by 45.6% for patterned sapphire substrate LEDs and by 41.9% for flat c-plane substrate LEDs. The enhancement of LEE through nanoscale surface corrugations was studied using 3-dimensional Finite Different Time Domain (FDTD) calculation. From the FDTD calculations, we were able to separate the light extraction from the top and bottom sides of device. This process revealed that light extraction from the top and bottom sides of a device strongly depends on the substrate and the surface corrugation. We found that enhanced LEE could be understood through the mechanism of enhanced light transmission due to refractive index matching and the increase of light scattering from the corrugated surface. LEE calculations for the encapsulated LEDs devices also revealed that low LEE enhancement is expected after encapsulation due to the reduction of the refractive index contrast.