• Title/Summary/Keyword: Weight Losses

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Design of PWM Inverter-Mounted Induction Motor System (PWM 인버터 탑재형 유도전동기 시스템 설계)

  • Shin, Woo-Seok;Yang, Soon-Bae;Lee, Don-Si;Choe, Gyu-Ha
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.325-329
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    • 1994
  • This paper describes a compact design and control method of PWM inverter-mounted induction motor especially designed for reducing the size and weight considerably, which may be applied to the speed control system such as air conditionr,conveyor and textile mill, etc. To obtain higher power density without derating performance, a new mechanical configuration unifying the inverter circuit and motor is proposed. Also, through the use of current minimization control method during V/f operation it is possible to reduce the size of heat-sink related to the losses of power circuit. By the proposed design method, a compact inverter-mounted induction motor system of 1Hp is built and its validity can be verified through the experimental results.

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A Studies on the Epidemiology of Caprine Anaplasmosis in Korea II. Therapy with Long Acting Terramycin (산양의 Anaplasmosis에 대한 역학적 조사 II . Terramycin을 이용한 치료시험)

  • 서석열;서이원;조선기;허철호;김동선;손구례;백병걸
    • Korean Journal of Veterinary Service
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    • v.17 no.1
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    • pp.54-60
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    • 1994
  • Anaplasmosis is a tick-borne disease mainly of cattle, sheep, and goats. Anaplasmosis in goat had been reported at last year by authors. The disease brought the economic losses in the goat farm in Chonbuk province. In order to treat the disease, a long-acting formulation terramycin injectable solution was used experimental animals which indigenous goats were sick with moderate anemia. We were devided into two groups was treated with single dosage (20mg /kg of body weight). one group was treated with single injection, the other group was treated with twice of the same dosage intramusculary injection. The results indicate that the use of long-acting terramycin would minimize clinical signs of anaplasmosis infection in goat. After treament the differrences of hematological appearences and parasitaemia were observed in the effect of terramycin treatment. obviously, increased value of RBC. HB and HCT, and parasitaemia by means of Giemsa staining and acrydine orange staining was observed decreased due to treatment.

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PATHOLOGIC STUDIES ON SODIUM MONOFLUOROACETATE (COMPOUND 1080) POISONING IN RABBITS (Sodium monofluoroacetate (Compound 1080) 중독(中毒)에 관(關)한 가토(家兎)의 병리해부학적(病理解剖學的) 연구(硏究))

  • Kim, Hwa Sik
    • Korean Journal of Veterinary Research
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    • v.1 no.1
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    • pp.65-70
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    • 1961
  • Many losses in domestic animals have bern reported in this country, since sodium monofluoroacetate (Compound 1080) was used as a rodenticide. Lesions described inclubed multiple petechiae in epi- and endocardium, lung and intestinal mucosa, or superficial necrosis of the gastric mucosa. In this studies as to the poisoning 7 rabbits were administered 0.6mg (Group I), 0.4mg (Group II), and 0.3mg (Group III) of sodium monofluoroacetate per kilogram of body weight. and the results obtained were as follows: In addition to the changes mentioned above fatty degeneration in central parts of hepatic lobule or nut meg liver, haemorrhagic feci in cerebral cortex and leptomeninges and fatty degeneration in kidney and cardiac muscles were found.

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Development of Battery Charger for Electric Vehicle using the LLC Resonant Converter (LLC 공진형 컨버터를 적용한 전기자동차 고압배터리 충전기 개발)

  • Kim, Gyoung-Man;Yoo, Jong-Uk;Kim, Tae-Kwon;Kang, Chan-Ho;Chun, Tae-Won
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.5
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    • pp.443-447
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    • 2013
  • This paper deals with LLC resonant converter of on-board charger for electric vehicle charging. Generally, the on-board charger must have a very widely charging voltage, higher efficiency, higher power factor, lower volume and lower weight. For reducing the switching losses, voltage and current stress of the device, the on-board charger is apply the half-bridge LLC resonant converter topology. To have a wide voltage range, it is design the hardware parameters and determine the switching frequency range of the LLC resonant converter. The experimental results show a wide charge voltage.

Study on Soft-Switching Forward-Flyback PWM DC/DC Converter using Assistant-Circuit (보조회로를 응용한 소프트 스위칭 Forward-Flyback PWM DC/DC 컨버터에 관한 연구)

  • 박성준;오세욱;계문호;김광태;김철우
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.4
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    • pp.90-99
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    • 1998
  • The DC/DC power converter increase switching frequency in order to achieve small size, a low noise, and light weight. However, the power switches have high power losses and switching stresses as the switching frequency is increased. Therefore in this paper, the author propose the Soft-Switching Forward-Flyback PWM DC/DC converter using assistant-circuit, based on forward-flyback operation of a high-frequency transformer. The proposed converter scheme is verified by simulation and experiment.

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Solid Particle Erosion of Plasma-Sprayed Coatings (플라즈마 용사시킨 Carbide Coating층의 공상입자 Erosion 특성에 관한 연구)

  • 전승범;남승훈;김종집;이주진
    • Journal of the Korean institute of surface engineering
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    • v.23 no.2
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    • pp.11-17
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    • 1990
  • The erosion characteristice of plasma-sprayed tungsten carbide chromium carbide coatings were investigated. Erosion tests were perfomed at room temperature by using Al2O3 and SiC particles accleerated in air stream. Weight losses of the coatings were measured over a range of paricle velocities and impingement angle. It was found that, for both of this coatings, the maximum erosion occurrd at a normal angle of impact, and the erosion rate at this impact angle was a power function of pparticle velocity. The values of the velocty emponent were between 3.07 and 3.50 Erosion value of chromium carbide coating was higher than that of tungsten carbide coating.

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Inactivation of Castor Bean Allergen CB-1A by Heating and Chemical Treatment

  • Kim, Byong-Ki
    • Food Science and Biotechnology
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    • v.15 no.3
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    • pp.441-446
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    • 2006
  • The biological effects of heating and chemical treatment on castor meal were investigated in order to develop a procedure to inactivate its antigenic activity in a way that is suitable for industrial applications. A 1% solution of purified castor bean allergen (CB-1A) was heat-treated with or without exposure to NaOH and NaOCI (250 ppm each). CB-1A exhibited extreme stability when heat-treated alone. In the presence of NaOH and NaOCl, CB-1A showed a drastic decrease in antigenic activity as the temperature surpassed the critical level of $70^{\circ}C$. The gradual disappearance of disc gel electrophoresis bands presumably responsible for the allergenicity of CB-1A, along with the significant losses of the amino acids phenylalanine, methionine, arginine, histidine, and cysteine correlated with the loss of CB-1A activity. CB-1A showed a single symmetrical band in SDS acrylamide gel electrophoresis with an estimated molecular weight of 6,000 daltons. The chemical and heat treatments reduced the disulfide bond content of CB-1A by 9.1% with a coincident increase in sulfhydryl bonds.

A Study on Battery Chargers for the next generation high speed train using the Phase-shift Full-bridge DC/DC Converter (위상전이 풀-브리지 DC/DC 컨버터를 이용한 차세대 고속 전철용 Battery Charger에 관한 연구)

  • Cho, Han-Jin;Lee, Won-Cheol;Lee, Sang-Seok;Kim, Tae-Hwan;Won, Chung-Yuen
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.623-628
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    • 2009
  • There is an increasing demand for efficient high power/weight auxiliary power supplies for use on high speed traction application. Many new conversion techniques have been proposed to reduce the voltage and current stress of switching components, and the switching losses in the traditional pulse width modulation(PWM) converter. Especially, the phase shift full bridge zero voltage switching PWM techniques are thought most desirable for many applications because this topology permits all switching devices to operate under zero voltage switching(ZVS) by using circuit parasitic components such as leakage inductance of high frequency transformer and power device junction capacitance. The proposed topology is found to have higher efficiency than conventional soft-switching converter. Also it is easily applicable to phase shift full bridge converter by applying an energy recovery snubber consisted of fast recovery diodes and capacitors.

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A Study on the Battery Charger for Next Generation High Speed Train (차세대 고속 전철용 Battery Charger 에 관한 연구)

  • Jeong, Han-Jeong;Lee, Won-Cheol;Lee, Sang-Seok;Paik, Jin-Sung;Won, Chung-Yuen
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.321-324
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    • 2008
  • Recently, there is an increasing demand for efficient high power/weight auxiliary power supplies for use on high speed traction application. many new conversion techniques have been proposed to reduce the voltage and current stress of switching components, and the switching losses in the traditional pulse width modulation(PWM) converter. Among them, the phase shift full bridge zero voltage switching PWM techniques are thought most desirable for many applications because this topology permits all switching devices to operate under zero voltage switching(ZVS) by using circuit parasitic components such as leakage inductance of high frequency transformer and power device junction capacitance. The proposed topology is found to have higher efficiency than conventional soft-switching converter. Also it is easily applicable to phase shift full bridge converter by applying an energy recovery snubber consisted of fast recovery diodes and capacitors.

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Study on intense pulse lighting with high efficiency (고효율의 Intese Pulse Light에 특성연구)

  • Kim, Whi Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.333-336
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    • 2009
  • the equipment increase switching frequency in order to achieve small size, a low noise, and light weight. however, the power switches have high power losses and switching stresses as the switching frequency is increased. In order to solve like this problem point from the present paper it proposed Intese Pulse Light of the half bridge methods which apply the start current circuit which applies the auxiliary equipment. Simulation and experimental result it leads and it brings is more qualitative there is 20% improvement and it confirmed that a possibility of measuring to the patient.

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