• Title/Summary/Keyword: Temperature Increase

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The electrical and optical properties of Xe plasma in flat lamp (평판형 광원에서 제논(Xe) 플라즈마의 전기적 광학적 특성 연구)

  • Pack, Gwang-Hyeon;Yang, Jong-Kyung;Lee, Jong-Chan;Chio, Yong-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.60-64
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    • 2005
  • Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important, distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp, we tested the discharge from 100 Torr to 300 Torr pressure, the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

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Electrical and Optical Properties of Xe Plasma in Flat Lamp (평판형 광원에서 제논 플라즈마의 전기적 및 광학적 특성)

  • Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.12a
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    • pp.71-74
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    • 2006
  • Discharge of the flat lamp lighting source research arc requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp. we tested the discharge from 100 Torr to 300 Torr pressure. the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

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Electrical and Optical properties of Xe gas in flat lighting source (제논(Xe) 가스를 사용한 평판형 광원에서의 전기 및 광학적 특성 연구)

  • Pack, Gwang-Hyeon;Yang, Jong-Kyung;Lee, Jong-Chan;Choi, Yong-Sung;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2190-2192
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    • 2005
  • Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp. we tested the discharge from 100 Torr to 300 Torr pressure. the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

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Correlation between water temperature and catch at a set net in Yeosu Bay, Korea

  • Choo, Hyosang
    • Fisheries and Aquatic Sciences
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    • v.24 no.1
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    • pp.41-52
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    • 2021
  • Data for fish species composition and the catch of fish species were obtained from the daily trading records for the period between April and December 2016 to 2018 at the set net fishing grounds in Yeosu Bay, Korea. The annual mean total catch was 195.8 tons, and the dominant species was the Spanish mackerel (Scomberomorus niphonius), which accounts for about 55 percent of the total catch. The catch increased in spring and autumn. Increase in spring is caused by not Spanish mackerel but other fish while the increase in autumn by Spanish mackerel. The distinct increase of the catch in summer, 2017 was due to the new recruitment of small-sized Spanish mackerel, which was probably to be from the fish population hatched in spring in the East China Sea. Our results showed a strong correlation between water temperature and catch fluctuation. The catch increases with the increase in water temperatures, and the periodic pattern of the water temperature and catch fluctuation is more consistent in the offshore waters, in which warm current flows, than in the coast waters.

A Study of BioSignal Analysis for Physical Activity of Wu-Shu Training (우슈 수련자의 신체활동에 따른 생체신호 분석에 관한 연구)

  • Kim Chang-Mo
    • The Journal of the Korea Contents Association
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    • v.5 no.6
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    • pp.230-237
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    • 2005
  • In this paper, we are suggested a method that's a major topics in sports medicine. It is disease control, control and management of chronic degenerative disease, and promotion of health. We are analyze physical activity to scientific and quantitative a trainee at Wu-Shu gymnasium, for a suggested method. We are measured a quantity of physical activity by SenseWear-PRO2-Armband which develop body-media company. Armband include to skin temperature sensor, near-body temperature sensor, accelerometer, heat flux sensor, galvanic skin response sensor. Acquired data was recorded to storage in Armband. We are analyzed using InnerView Wearer Software in the Stored data to skin temperature, calorie expenditure, quantity of physical activity. The result of this analyzed, we are know that a man of long-term exercise expenditure energy at short time and if liveliness of physical activity was Increase in expenditure energy with increase skin temperature. Also, we are know that the heat flux after increase expenditure energy with increase skin temperature. And, know that GSR was not affected a factors that physical activity, expenditure energy, increase skin temperature, and others.

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Effect of Cooling Rate on Thermal Shock Behavior of Alumina Ceramics ($Al_2O_3$ 세라믹스 열충격에 미치는 냉각 조건의 영향)

  • 한봉석;이홍림;전명철
    • Journal of the Korean Ceramic Society
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    • v.34 no.7
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    • pp.767-773
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    • 1997
  • Thermal shock behavior of alumina ceramics were studied by quenching the heated alumina specimen into the water of various temperatures over 0~10$0^{\circ}C$. The critical thermal shock temperature difference ( Tc) of the specimen decreased almost linearly from 275$^{\circ}C$ to 20$0^{\circ}C$ with increase in the cooling water temperature over 0~6$0^{\circ}C$. It is probably due to the increase of the maximum cooling rate which is dependent of the convection heat transfer coefficient. The convection heat transfer coefficient is a function of the temperature of the cooling water. However, the critical thermal shock temperature difference( Tc) of the specimen increased at 25$0^{\circ}C$ over 80~10$0^{\circ}C$ due to the film boiling of the cooling water. The maximum cooling rate, which brings about the maximum thermal stress of the specimen in the cooling process, was observed to increase linearly with the increase in the quenching temperature difference of the specimen due to the linear relationship of the convection heat transfer coefficient with the water temperature over 0~6$0^{\circ}C$. The critical maximum cooling rate for thermal shock fracture was observed almost constant to be about 260$\pm$1$0^{\circ}C$/s for all water temperatures over 0~6$0^{\circ}C$. Therefore, thermal shock behavior of alumina ceramics is greatly influenced by the convection heat transfer coefficient of the cooling water.

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Effect of Air Velocity on Combustion Characteristics in Small-Scale Burner

  • Laryea, Gabriel Nii;No, Soo-Young
    • Journal of the Korean Society of Combustion
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    • v.10 no.1
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    • pp.1-6
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    • 2005
  • This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressure-swirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates ranging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2$, NOx, $SO_2$, flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity on $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

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Effect of Air Velocity on Combustion Characteristics Scale Burner

  • Laryea, Gabriel Nii;No, Soo-Young
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • v.10 no.1
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    • pp.76-82
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    • 2005
  • This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressureswirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates raging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2,\;NOx,\;S0_2,$ flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$ concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

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Thermal Stress Evaluation by Elastic-Creep Analysis during Start-up of Boiler Header (보일러 헤더 기동시의 탄성 크리프 해석에 의한 열응력 평가)

  • Shin, Kyu-In;Yoon, Kee-Bong
    • Journal of the Korean Society of Safety
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    • v.24 no.2
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    • pp.17-22
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    • 2009
  • Thermal stress and elastic creeping stress analysis was conducted by finite element method to simulate start-up process of a boiler header of 500MW standard fossil power plant. Start-up temperature and operating pressure history were simplified from the real field data and they were used for the thermal stress analysis. Two kinds of thermal stress analysis were considered. In the first case only temperature increase was considered and in the second case both of temperature and operating pressure histories were considered. In the first analysis peak stress was occurred during the temperature increase from the room temperature. Hence cracking or fracture may occur at the temperature far below the operating maximum temperature. In the results of the second analysis von Mises stress appeared to be higher after the second temperature increase. This is due to internal pressure increase not due to the thermal stress. When the stress components of radial(r), hoop($\theta$) and longitudinal(z) stress were investigated, compression hoop stress was occurred at inner surface of the stub tube when the temperature increased from room temperature to elevated temperature. Then it was changed to tension hoop stress and increased because of the operating pressure. It was expected that frequent start-up and shut-down operations could cause thermal fatigue damage and cracking at the stub tube hole in the header. Elastic-creeping analysis was also carried out to investigate the stress relaxation due to creep and stabilized stress after considerable elapsed time. The results could be used for assessing the creep damage and the residual life of the boiler header during the long-tenn service.

The study of combustion gas characteristic by incinerator operation condition. (소각로 운영조건에 따른 연소배가스 특성 연구)

  • Lee, Keon-Joo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.18 no.1
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    • pp.66-72
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    • 2010
  • This study was done to analyze the condition of combustion exhaust gas that is produced according to incinerator operating condition in A area Kyonggido. The boiler exhaust gas temperature, the oxygen concentration of boiler, the outgassing temperature of Semi Drying Sorber(SDS), the temperature of catalytic reactor, the concentration of NOx, SOx, CO, Hcl and Dust were investigated by change the temperature of incinerator. The concentration of SOx, CO, HCL and DUST were below 5 ppm as increase the temperature of incinerator however the concentration of NOx was increased from 40 ppm to 70 ppm as increase the temperature of incinerator. The boiler exhaust gas temperature and the temperature of catalytic reactor were not changed however the oxygen concentration of boiler was decreased gradually as increase the temperature of incinerator.