• 제목/요약/키워드: Temperature condition

검색결과 11,223건 처리시간 0.048초

Thermal Analysis of a Spent Fuel Storage Cask under Normal and Off-Normal Conditions

  • Lee, J. C.;K. S. Bang;K. S. Seo;Kim, H.D.;Park, B. I.;Lee, H. Y.
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.601-608
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    • 2003
  • Thermal analyses have been carried out for a spent fuel dry storage cask under normal and off-normal conditions. Environmental temperature is assumed to be $15^{\circ}C$ under the normal condition. The off-normal condition has an environmental temperature of $38^{\circ}C$. An additional off-normal condition is considered as a partial blockage of the air inlet ducts. Two of the four air inlet ducts are assumed to be completely blocked. The maximum temperatures of the fuel rod and concrete overpack were lower than the allowable values under the normal condition. Temperature distributions for the off-normal conditions were slightly higher than the normal conditions.

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온도(溫度) 및 삽목조건(揷木條件)이 백리향의 발아(發芽)와 발근(發根)에 미치는 영향(影響) (Effect of Temperature and Cutting condition on Germination and Rooting of Thymus quinquecstaus)

  • 박노복;권영휴
    • 현장농수산연구지
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    • 제11권1호
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    • pp.95-101
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    • 2009
  • 약용 및 관상식물로 개발가치가 있는 백리향의 종자발아 및 삽목조건 구명을 위한 몇 가지 실험결과는 아래와 같다. 종자발아는 20℃ 광 조건에서 89%의 발아율로 가장 좋았다. 적정 삽목시기는 5월20일이 94%의 발근율로 가장 양호했고, 삽목용토는 단용보다는 peatmoss(50%) + perlite(50%) 혼용처리에서 좋았으며 삽목전 삽수의 IBA 처리농도는 100mg/L 침지처리에서 96% 발근율을 나타내었다.

신경회로망을 이용한 극저온 절삭특성의 예측 (The Prediction of the Cutting Characteristics in Cryogenic Cutting Using Neural Network)

  • 김칠수;오석영;오선세
    • 한국정밀공학회지
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    • 제13권10호
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    • pp.62-70
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    • 1996
  • We experimented on cutting characteristics-cutting force, behavior of cutting temperature, surface roughness. chip thickness under low temperature, which generated by liquid nitrogen(77K). The work-pieces were freezed to-195 .deg. C and liquid nitrogen was also sprinkled on cutting area in order to decrease an experimental error of machining in low temperature. The workpiece was became to -195 .deg. C in5 minutes. In cooled condition surface roughness of workpiece was better than normal condition. In addition, we investigated the possibility that surface roughness of workpiece and cutting force can be predicted analyzing cutting conditions by the trained neural network.

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도핑 공정에서의 Pre-deposition 온도 최적화를 이용한 Solar Cell 효율 개선 (Solar Cell Efficiency Improvement using a Pre-deposition Temperature Optimization in The Solar Cell Doping Process)

  • 최성진;유진수;유권종;한규민;권준영;이희덕
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.244-244
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    • 2010
  • Doping process of crystalline silicon solar cell process is very important which is as influential on efficiency of solar. Doping process consists of pre -deposition and diffusion. Each of these processes is important in the process temperature and process time. Through these process conditions variable, p-n junction depth can be controled to low and high. In this paper, we studied a optimized doping pre-deposition temperature for high solar cell efficiency. Using a $200{\mu}m$ thickness multi-crystalline silicon wafer, fixed conditions are texture condition, sheet resistance($50\;{\Omega}/sq$), ARC thickness(80nm), metal formation condition and edge isolation condition. The three variable conditions of pre-deposition temperature are $790^{\circ}C$, $805^{\circ}C$ and $820^{\circ}C$. In the $790^{\circ}C$ pre-deposition temperature, we achieved a best solar cell efficiency of 16.2%. Through this experiment result, we find a high efficiency condition in a low pre-deposition temperature than the high pre-deposition temperature. We optimized a pre-deposition temperature for high solar cell efficiency.

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저온습윤 저장기간, 발아온도 및 차광율이 눈개승마 종자의 발아에 미치는 영향 (Effects of Storage Duration with Low Temperature and Wet Condition, Germination Temperature and Shading Rate on Germination of Aruncus dioicus var. kamtschaticus Seeds)

  • 송기선;전권석;최규성;김창환;박용배;김종진
    • 한국약용작물학회지
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    • 제23권5호
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    • pp.370-378
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    • 2015
  • Background : Aruncus dioicus var. kamtschaticus, functional wild vegetable, is perennial herb and young leaves with soft texture are generally used as edible food. So the demand for the vegetable has increased recently. This study was carried out to determine the effects of temperature and shading on germination characteristics of A. dioicus. Methods and Results : The experiment was performed by temperature and shading treatments. Seed pre-treatment before the germination experiment was carried out by the storage in low temperature ($4^{\circ}C$) under wet condition (LTW) for 0, 15, 30, 45 and 60 days and shading treatment were 35%, 50%, and 75% under control, BA (6-benzyladenine) and $GA_3$ (gibberellic acid) condition for 24 hours. Increasing the length of the storage periods led to increases seed germination percent in low temperature ($4^{\circ}C$) under wet condition (LTW), germination rate of A. dioicus seed was the highest at $15^{\circ}C$ with 60 days of seed pre-treatment. In the case of seeds pre-treatment with LTW, the more temperature went up, the more days to 50% of Germination of Final Germination Rate ($T_{50}$) went down. As a result of surveying shading treatment, germination rate was the highest in control of 35% shading and the next higher was in control of 50% shading. Conclusions : It is concluded that the temperature and shading are important factors to produce A. dioicus. Also, We suggest these results as basic data of A. dioicus for sexual propagation.

퍼지제어기를 이용한 초음파 모터의 온도특성에 관한 연구-주파수 제어 (A study on the characteristic or temperature for Ultrasonic Motor using Fuzzy Controller - with frequency control)

  • 서기열;차인수;박해암;최장균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.597-599
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    • 1996
  • This paper describes the bending traveling-wave type ultrasonic motor which generates the traveling wave by combining two standing waves with phase difference time and space. In $+20^{\circ}C{\sim}30^{\circ}C$, the USM motor operation character has represented normal condition. But the other temperature, (that is say, when long time operating condition) USM operation characteristic has abnormal condition, that is driving frequency, drive current and r.p.m is down. The recent USM has controller without temperature compensation. This study aimed at fuzzy controller which must follow the frequency at operation temperature and then r.p.m and torque increase.

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퍼지제어기를 이용한 초음파 모터의 온도특성에 관한 연구 - 위상차 제어 (A Study on the characteristic of temperature for Ultrasonic Motor using Fuzzy Controller - with phase angle difference control)

  • 서기열;차인수;윤형상;유권종
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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    • pp.52-55
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    • 1996
  • This paper describes the bending traveling-wave type ultrasonic motor which generates the traveling wave by combining two standing waves with phase difference time and space. In $+20^{\circ}C$~$30^{\circ}C$, the USM motor operation character has represented normal condition. But the other temperature, (that is say, when long time operating condition) USM operation characteristic has abnormal condition, that is driving frequency, drive current and r.p.m is down. The recent USM has controller without temperature compensation. This study aimed at fuzzy controller which must follow the phase angle difference 90$^{\circ}$at operation temperature and them r.p.m and torque increase.

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고온용 세라믹 열교환기 설계를 위한 수치 연구 (A Numerical Simulation for Design of High Temperature Ceramic Heat Exchanger)

  • 박경서;최종균;남진현;신동훈;박상환
    • 한국연소학회지
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    • 제14권3호
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    • pp.24-28
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    • 2009
  • To improve its efficiency, most of the industrial furnace had been used recuperator. However, commonly used metal recuperator is not suitable under condition of temperature higher than $1000^{\circ}C$. The other hand, ceramic recuperator is able to use in high temperature condition. In the present study, the design program based on the basic heat exchanger design theory, and CFD modelling are applied to ceramic recuperator to verify the design results. Using design program to find the optimum design factor on the variation of recuperator condition. The result of this study are as follows : Thinner fin-plate thickness reduces pressure drop and increases heat-transfer rate, However, thin plate or plate with thin thickness(< 5 mm) is difficult to manufacture, due to limited mechanically strength.

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온도특성을 고려한 저압간선의 경제적인 설계기법에 관한 연구 (A Study on the Economical Design of Low-Voltae feeder Considering the temperature character)

  • 최홍규;조계술
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2002년도 학술대회논문집
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    • pp.349-354
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    • 2002
  • A size of low-voltage conductor cables is determined by the voltage drop of a system, the cable impedance and the cable ampacity based on temperature correction factor in accordance with the condition of cable installation. Therefore, the proper temperature correction factor according to the condition of cable installation should be applied to determining the cable ampacity and also the skin effect and proximity effect, along with the kind and size of conductor and the condition of cable installation, should be properly considered to analyze the proper value of resistance and the reactance of the conductors. This paper addresses the systematic design flow for determining the size of low voltage level conductor cables in calculating the temperature character where error should be minimized in comparison with the general formula and which can be applied in design work for determining the size of conductor cables.

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버어리 잎담배의 적정 토스트 가동 조건 설정 (Establishment of Proper Toasting Condition on Burley Leaf Tobacco)

  • 정한주;김용옥
    • 한국연초학회지
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    • 제26권1호
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    • pp.50-56
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    • 2004
  • The quality of burley leaf tobacco was affected by various toasting conditions. In this study, we determined main factor to influence the quality of burley tobacco on toasting and established proper toasting condition to improve the quality of toasted tobacco. Our results indicated that the main factor to influence the quality of burley tobacco was the amount of treatment and 3rd drying zone temperature. We also found that the proper toasting conditions to improve the quality of toasted tobacco and reduce the smoking irritation were moisture content (34 %), amount of treatment (1,520kg/hr), 1st drying zone temperature (135$^{\circ}C$), 2nd zone drying temperature(145$^{\circ}C$) and 3rd zone drying temperature (147$^{\circ}C$).