• Title/Summary/Keyword: EHV

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Protection of Specific-pathogen-free (Spf) Foals from Severe Equine Herpesvirus Type-1 (Ehv-1) Infection Following Immunization with Non-infectious L-particles

  • Mohd Lila Mohd-Azmi;John Gibson;Frazer Rixon;Lauchlan, John-Mc;Field, Hugh-John
    • Journal of Microbiology
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    • v.40 no.3
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    • pp.183-192
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    • 2002
  • Cells infected With equine herpesvirus type-1 (EHV-1) Produced both infectious and non-infectious Virus-related particles. Compared to the whole virion, non-infectious particles termed L-particles were deter-mined to lack 150 kDa protein, commonly known as nucleocapsid protein. The potential of L-particles to induce immune responses was studied in mice and foals. Intranasal immunization with L-particles or whole virions induced poor IgG antibody responses in mice. Interestingly, despite the poor antibody response, the conferred immunity protected the host from challenge infections. This was indicated by a significant reduction in virus titers in line with recovery towards normal body weight. Subsequently, the test on the usefulness of L-particles as immunizing agents was extended to foals. Immunization of specific-pathogen-free (SPF) foals resulted in similar results. As determined by a complement-fixing-antibody test (CFT), foals seroconverted when they were immunized either with inactivated L-particles or whole virions via intramuscular (i.m.) injections. The presence of the antibody correlated with the degree of protection. Beyond day 1 post challenge infection (p.i.), there was no virus shedding in the nasal mucus of foals immunized with whole EHV-1 virions. Virus shedding was observed in foals Immunized with L-particles but limited to days 6 to 8 p.i. only. In contrast, extended vim shedding was observed in non-immunized foals and it was well beyond day 14 p.i. Viremia was not detected for more than four days except in non-immunized foals. Immunization in mice via intranasal (i.n.) conferred good protection. However, compared to the i.n. route, a greater degree of protection was obtained in foals following immunization via i.m. route. Despite variation in the degree of protection due to different routes of immunization in the two animal species, our results have established significant evidence that immunization with L-particles confers protection in the natural host. It is suggested that non-infectious L-particles should be used as immunizing agents for vaccination of horses against EHV-1 infection.

Assessment and Management Method of Flicker Emission Level Based on IEC 61000-3-7 for Domestic Extra-high Voltage Customers (국내 특고압 고객에 대한 IEC 61000-3-7 기반의 플리커 방출한계 평가 및 관리 방안 연구)

  • Han, Su-Kyoung;Shin, Hoon-Chul;Park, Sang-Ho;Kim, Kern-Joong;Cho, Soo-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.1
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    • pp.1-7
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    • 2018
  • IEC 61000-3-7 provides guidance for limiting flicker and enabling the connection of fluctuating load installations, that is, producing flicker in MV, HV and EHV power systems. In Korea, the flicker have been restricted by Japanese standard of ${\Delta}V_{10}$ method. ${\Delta}V_{10}$ was developed only for arc furnaces in 1960's. And now it is revealed that it is not suitable for application to other fluctuating load installations through many researches. $P_{st}$ which is a flicker index used in IEC 61000-3-7, indicates visual inconvenience due to voltage fluctuation across large range of frequency and can be applied to fluctuating load installations as well as arc furnaces. In this paper, we introduce how to calculate and assess flicker emission level for the individual fluctuating load installations connected in EHV system and how to manage the emission levels in the power system according to IEC 61000-3-7.

Selection of Transformer for the Augmentation of an Existing AIS EHV Substation in Hilly Terrain at 3000m+ Altitude

  • Kim, Kwang-Soo;Kang, Byoung-Wook;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.28-36
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    • 2012
  • Augmentation of existing EHV substations located in hilly terrain and at high altitude require many different considerations as compared to substations located in plain areas and at lower altitude. Owing to high altitude and steep terrain, meticulous engineering and preparations are required, considering the actual available space at the existing substation. Historical fault events too must be considered to enhance reliability and performance of the substation equipment. This paper proposes ways to augment the existing 2 banks of 20MVA, 220/66kV power transformers ($3{\times}6.67MVA$, single-phase) to $2{\times}50$/63MVA, 220/66kV power transformers to meet continuously increasing demand of the capital city over the next 20 years. Upgrading and augmentation of existing substations, especially the main transformers and associated equipment, require replacement with minimum or no disturbance to the existing power supply system. Considerations should also be made during engineering and design, the operational flexibilities, maintenance aspects, future expandability and value addition, in terms of reliability and space usage of the existing substation.

Studies on isolation of rhinopneumonitis virus from Korean horses and its immunogenicity III. Studies on immunogenicity of equine herpesvirus in experimental animals (국내 말로부터 비폐렴바이러스의 분리 및 면역원성에 관한 연구 III. 말 비폐렴바이러스의 실험동물에 대한 면역원성 조사)

  • Cho, Gil-jae;Kim, Bong-hwan;So, Sin-hee;Lee, Du-sik
    • Korean Journal of Veterinary Research
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    • v.35 no.4
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    • pp.753-758
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    • 1995
  • The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.

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Design of Dielectric Detector for FRP Hot Stick in EHV Live line Maintenance

  • Chawporn, Talerngkiat;Sriratana, Witsarut;Trisuwannawat, Thanit
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2063-2066
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    • 2005
  • This paper presents an approach to detect the dielectric condition of FRP Hot Stick in EHV high voltage cable whereas shutting down the power system is not necessary. The radio frequency generating method is adopted by transmitting radio wave into the Electrodes. This instrument is small, easy to use and also inexpensive. Furthermore, the impurity level of dirt on high voltage insulator (non-ceramic type) will be analyzed by using the methods based on IEEE Std.978-1984 at 105 kV.DC. /305 mm. and OSHA Regulation 1910.269 Part J - live line tools. The frequency at 10-20 MHz is applied to FRP Hot Stick via Electrode1 and from FRP Hot Stick surface to Electrode 2. After that the results will be evaluated by testing in each condition of FRP Hot Stick, such as dry surface, hot surface, foil winding and conductor inserting. Finally, the watt loss will be examined and compared with the loss from humidity and Carbon tracking. The important components of this system are radio frequency generating unit, frequency stabilizing unit, frequency amplifier, FRP Hot Stick frequency counter, processing unit, and display unit.

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Verification of Insulation Design for Three Phase Enclosure Type EHV Class GIB by 3D Electric Field Analysis (3차원 전계해석에 의한 3상일괄형 초고압 GIB의 절연설계 검증)

  • Chong, J.K.;Park, K.Y.;Shin, Y.J.;Chang, K.C.;Song, K.D.;Song, W.P.;Kweon, K.Y.;Lee, C.H.
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.482-484
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    • 1995
  • In designing three phase enclosure type EHV class gas insulated bus (GIB), it is essential to estimate the magnitude and the position where the maximum electric field strength occur. The improvement of insulation design can only be initiated after those informations have been obtained. In this paper, the calculated electric field strength for three phase GIB of HICO 362kV 63kA GIS is presented. The result shows that the designed insulator has enough margin compared with the design criteria.

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The Application of Al-foil Electrode for Detecting Partial Discharge Signal in Middle Joint Box of EHV Power Cable (초고압 전력케이블용 중간 접속부 내의 부분방전신호 검출을 위한 박전극 응용)

  • Lee, Yong-Sung;Yang, Jong-Kyung;Yang, Jong-Keok;Choi, Yong-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.142-144
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    • 2005
  • To detect partial discharge of 154kV joint box, we have made experiment by using the Al-foil electrode sensor. Generally the signals which are detected in partial discharge test of underground power transmission cable are accompanied wi th both noises of high voltage and noises of surrounding power cable. The most noise in near to end part of joint box is corona, beside other noises flowed from surrounding area. Partial discharge test is difficulty due to these noises. First, we had used Al-Foi1 sensor on middle joint box of 154[kV] underground transmission power cable, and then analyzed reliability of calibration signal by using the Al-Foi1 electrode sensor of NJB. From above results, decrement properties measured highly. But incase of injecting calibration signal of 500[pC] after measuring signals in IJB, the S/N ratio had about 25[dB] acquisition.

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Study on the AC Interfacial Breakdown Properties in the Interface between toughened Epoxy and Silicone Rubber (Toughened 에폭시와 실리콘고무 계면의 교류 절연파괴 현상에 관한 연구)

  • 박우현;이기식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1079-1084
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    • 2002
  • Because complex insulation method is used in EHV(extra high voltage) insulation systems, macro Interfaces between two different bulk materials which affect the stability of insulation system exist inevitably. Interface between toughened epoxy and silicone rubber was selected as a interface in EHV insulation systems and tested AC interfacial breakdown properties with variation of many conditions to influence on electrical Properties, such as interfacial pressure, roughness and oil. Specimen was designed to reduce the effect of charge transport from electrode in the process of breakdown and to have the tangential electrical potential with the direction of the interface between epoxy and silicone rubber by using FEM(finite elements method). It could control the interfacial pressure, roughness and viscosity of oil. From the result of this study, it was shown that the interfacial breakdown voltage is improved by increasing interfacial Pressure and oil. In particular, the dielectric strength saturates at certain interracial Pressure level. The decreasing ratio of the interfacial breakdown voltage in non-oiled specimen was increased by the temperature rising, while oiled specimen was not affected by temperature.