• Title/Summary/Keyword: BTA

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A Study on the Electrification Mechanism in UHV Transformer by Couette Flow (Couette 흐름현상을 이용한 초고압변압기의 유동대전 기구 연구)

  • 곽희로;정용기;권동진
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.9 no.4
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    • pp.93-102
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    • 1995
  • The purpose of this paper is to analyze the streaming electrification mechanism (SEM) generated in UHV transformer. This experiment used Couette Charger and interpreted the mechanism hydromechanically and electromagnetically. This work estimated the turbulent core density ($\rho$o) by measuring the short circuit current (isc) and the open circuit voltage (νoc) generated in Couette Charger and also studied the changes of the short circuit (isc), the open circuit voltage (νoc), the turbulent core density ($\rho$o) and the conductivity ($\sigma$) with adding BTA to restrain streaming electrification. as a result adding BTA increased the conductivity of oil and decreased the turbulent core density($\rho$o).

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A Study on Cutting Mechanism and Wear Character for BTA Drill (BTA드릴의 절삭 기구와 마모 특성에 관한 연구)

  • 장성규;전언찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.105-108
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    • 1995
  • So far,in deep drilling process there are several manufacturing problems such as hole deviation, hole over size, circularity,straightness and surface roughness. Whit regard to these problems, we atudied the abrasion process on carbided tip of BTA drill and got the follow test results through the abrasion characteristic test and analysis on cutting mechanism for the drill tooth and guide pad. 1) In SM55C drilling process, the most stable and reasonable drilling speed range for optmum abrasion characteristic of drill tooth was 60m.min. 2) The total drilling torque was about 60kg .deg.cm on condition drilling speed 60m/min and 0.15mm/rev. These results show that the theoretical burnising torque is well accord with the tested torque which is working on guide pad.

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Electrical properties of insulating oils for automobile ignition coil (자동차 점화코일용 절연유의 전기적 특성)

  • 신종열;홍진웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.172-177
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    • 1999
  • In this paper, the physical and electrical properties of the synthetic fluids No. 2 class Ⅶ used the insulating oils for automobile ignition coil are studied. Also, benzotriazole(BTA) as the streaming electrification suppressant additive is added to the oil, and the change of physical and electrical properties due to different BTA concentration is investigated. To investigate the electrical characteristics, the breakdown strength of each specimen by an experiment for AC breakdown and the changes of conductivity by measuring volume resistivity are analyzed. It is considered that the effective content of BTA as charge suppressant additive is about 10[ppm] from the results of AC breakdown and volume resistivity test.

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A Study on the Effect of Surfactants on the Streaming Electrification of Insulating Oil (절연유의 유동대전현상에 미치는 계면활성제의 영향에 관한 연구)

  • Chung, K.H.;Lim, K.B.;Kim, Y.W.;Park, J.Y.;Joe, K.S.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1534-1536
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    • 1997
  • In this paper, the streaming electrification phenomena of insulating oil by metal filters and the charge elimination method were investigated. When BTA and surfactant is molten in insulating oil, BTA appear the prevention of electrification from about 5ppm and surfactant (SP-S10, SP-S30) appear the prevention of electrification from about 20ppm. BTA increase the conductivity of insulating oil but surfactant and antioxidant(DBPC) isn't affect that.

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Construction of a 2D Co(II) Coordination Polymer with (4,4)-Connected Topology: Synthesis, Crystal Structure, and Surface Photo-electric Property

  • Li, Jia-Ming
    • Bulletin of the Korean Chemical Society
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    • v.35 no.4
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    • pp.1177-1181
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    • 2014
  • A 2D grid-like (4, 4)-connected topology coordination polymer, $[Co(BTA)_2(H_2O)_2]_n$ (1), where HBTA = 2-(1H-benzotriazol-1-yl)acetic acid, has been synthesized by hydrothermal method and characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy (SPS). X-ray diffraction analyses indicated that 1 displays octahedral metal centers with secondary building units (SBUs) [$Co(BTA)_2(H_2O)_2$] bridged by the $BTA^-$ ligands. In the crystal, the 2D supramolecular architecture is further supported by $O-H{\cdots}O$, $O-H{\cdots}N$, $C-H{\cdots}O$ hydrogen bonds and ${\pi}{\cdots}{\pi}$ stacking interactions. The SPS of polymer 1 indicates that there are positive response bands in the range of 300-600 nm showing photo-electric conversion properties. There are good relationships between SPS and UV-Vis spectra.

Volume Resistivity Characteristies of Transformer Oils due to the Stirring Temperalure of BTA (BTA 교반온도에 따른 변압기유의 체적고유저항 특성)

  • 이용우;김석환;박문규;소병문;김왕곤;홍진웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.290-293
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    • 1997
  • In this paper, volume resistivity is studied so that the electrical properties for transformer oil due to the stirring temperature of BTA is investigated. A measurement of volume resistivity using the VMG-1000 highmegohm meter is recorded after 10 minutes when the each voltage, and DC 100[V], 250[V], 500[V] and 1000[V] is applied, according to the step voltage appliaction method. A coaxial cylindrical liquid electrode to measure volume resistivity of specimen is used, and its geometric capacitance is 16[pF].

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Research of Flow Velocity and BTA According to the Streaming Electrification of Vegetable Insulating Oils (식물성 절연유의 유속과 BTA에 따른 유동대전 현상 연구)

  • Choi, Sun-Ho;Bang, Jeong-Ju;Huh, Chang-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.10
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    • pp.791-797
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    • 2012
  • Mineral insulating oils are an important insulating materials in oil-filled transformer. However, the mineral oil is the cause of the environmental problem. The vegetable oils are substitutes for mineral oil because of its biodegradability characteristic. As large size and high rating of the transformer increases, the losses increase at a faster rate. So insulating oil is forced circulation in the oil-filled transformer by using oil pumps. The flow electrification occurs when insulating oil was forced to be circulated. To check the flow electrification, had conducted experiments varying factors. As a result, the streaming electrification could see the changes according to flow velocity, oil temperature and insulation materials.

The Effect of Additive on the Streaming Electrification (첨가제의 영향에 따른 유동대전특성 조사)

  • 최창락;임헌찬;박재윤;정재희;성낙진;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.357-360
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    • 1995
  • Since the streaming electrification phenomena of transformer were made clear on 1970s, many researches have been continued on the improvement of the transformer. This paper describes the effect of additive (BTA, DBPC) and temperature on the streaming electrification of the various materials. The streaming current in the various materials decreases in proportion to the concentration of BTA, results in the inverse electrification. We believe that these results will contribute to the optimal design of HV large-capacity transformer.

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Detection of Quantitative Trait Loci for Growth and Carcass Traits on BTA6 in a Hanwoo Population

  • Lee, Y.-M.;Lee, Y.S.;Han, C.-M.;Lee, J.-H.;Yeo, J.S.;Kim, Jong-Joo
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.3
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    • pp.287-291
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    • 2010
  • The purpose of this study was to detect quantitative trait loci (QTL) for growth and carcass quality traits on BTA6 in a population of Hanwoo cattle. Three hundred and sixty one steers were produced from 39 sires that were sired by 17 grandsires in the two Hanwoo farming branches of the National Livestock Research Institute of Korea, between Spring 2000 and Fall 2002. DNA samples were collected for all of the steers, sires and grandsires, and the phenotypes for six growth and carcass quality traits were measured at 24 months of age. Twelve microsatellite markers were chosen on BTA6 and a linkage map was constructed by using seven of the twelve markers. Then, a chromosome-wide QTL scan was performed by applying an Animal Model, in which effects of QTL alleles within the grand sires were fitted as a random term. Three QTL were detected at the 5% chromosome-wise level for backfat thickness, average daily gain, and final weight. The most likely positions for the QTL were in the proximal region, i.e. 0 cM, 35 cM, and 63 cM, respectively. Also, another QTL for longissimus dorsi muscle area was detected at the 10% chromosome-wise level at 67 cM. These results were, in general, consistent with our previous report, in which candidate gene analyses showed that a SNP near ILSTS035 flanked by BM4621 (62.5 cM) and BMS2460 (81.3 cM) was associated with final weight, carcass weight, average daily gain, and longissimus dorsi muscle area in the same Hanwoo population.