• 제목/요약/키워드: Minimum Temperature

검색결과 2,218건 처리시간 0.028초

인산염이 쌀전분의 호화에 미치는 영향 (Effect of Phosphate on Gelatinization of Rice Starch)

  • 김일환;김성곤;이규한
    • 한국식품과학회지
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    • 제17권1호
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    • pp.5-7
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    • 1985
  • 인산염이 쌀전분의 호화에 미치는 영향을 X-ray 회절법으로 조사하였다. 인산염은 멥쌀전분의 호화에 필요한 수분을 감소시켰다. 5% 멥쌀전분 현탁액의 호화온도는 인산염에 의하여 영향을 받지 않았으나, 같은 온도에서는 인산염의 존재시 호화도는 높은 값을 보였다. 인삼염은 찹쌀전분의 경우 호화에 영향을 미치지 않았다.

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고온초전도 테이프를 이용한 다단 전류 도입선의 최적설계 (Optimal Design of Multi-Step Current Leads Using HTS Tapes)

  • 김민수;나필선;설승윤
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2001년도 학술대회 논문집
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    • pp.84-88
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    • 2001
  • The optimum cross-sectional area Profile of gas-cooled high-temperature superconductor (HTS) current lead is analyzed to have minimum helium boil-off rate. The conventional constant area HTS lead has much higher helium consumption than the optimum HTS lead considered in this study. The optimum HTS lead has variable cross-sectional area to have constant safety factor. An analytical formula of optimum shape of lead and temperature profile are obtained. For multi-step HTS current leads, the optimum tape lengths and minimum heat dissipation rate are also formulated. The developed formulations are applied to the Bi-2223 material, and the differences between constant area, constant safety-factor, and multi-step current leads are discussed.

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반응표면법을 이용한 최소동작시간을 갖는 DC 솔레노이드 밸브의 형상 최적 설계 (Shape Optimization of DC Solenoid Valve to Minimize the Time of Action Using Response Surface Method)

  • 윤희성;황인성;김동수;윤소남;고창섭
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권9호
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    • pp.449-458
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    • 2006
  • In general, a DC solenoid valve is evaluated by the performances such as the attraction force at maximum and minimum strokes, temperature rising, power consumption and time of action. The importance of each performance may be different according to the specific application purpose. When the temperature rising and power consumption are fixed, however, the performance of DC solenoid valve is usually evaluated by the attraction force at maximum and minimum strokes and time of action. In this paper, the shape of the pole face of plunger and core is optimized to increase the attraction force at maximum stroke, and thereby to minimize the time of action. For the shape optimization, (1+1) evolution strategy is incorporated with the response surface method(RSM) and finite element method(FEM).

리브 구조에 따른 머시닝센터 베드의 열적 특성 평가 (Thermal Characteristic Estimation of NC Machining Center Bed following Rib Structure)

  • 김양진
    • 한국생산제조학회지
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    • 제19권6호
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    • pp.746-752
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    • 2010
  • Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

커넥팅로드 베어링의 유막두께에 미치는 기관 운전조건 및 윤활유의 영향 (The Influence of Engine Operating Conditions and Lubricants on Oil Film Thickness of Engine Connecting Rod Bearing)

  • 이동호;장병주
    • 한국자동차공학회논문집
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    • 제2권5호
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    • pp.1-10
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    • 1994
  • By applying of total electric capacitance method on engine connecting rod bearing during engine operating, the influence of engine operating conditions and lubricants on bearing oil film thickness was investigated. Minimum oil film thickness increases with kinematic viscosity, but as increasing of viscosity, the increasing ratio of film thickness is reduced. Also minimum oil film thickness increases with engine speed but there is a limit. Above this limit, film thickness decreases in opposition because of crankshaft inertia. As increasing of engine torque and oil temperature, munimum oil film thickness decreases linearly. For non-Newtonian oils, the correlation between $100{\circ}C$ kinematic viscosity and munimum oil film thickness is very poor.

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CFD 연성해석과 유전자 알고리즘을 이용한 실내 열환경 최적설계에 관한 연구 (Optimal Design for Indoor Thermal Environment based on CFD Simulation and Genetic Algorithms)

  • 김태연;이윤규
    • 설비공학논문집
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    • 제16권2호
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    • pp.111-120
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    • 2004
  • The optimal design method of indoor thermal environment using CFD coupled simulation and genetic algorithms (GA) is developed in this study. CFD could analyze the thermal environment considering the distribution of temperature, velocity, etc. in a room. Therefore, It would be appropriate to use CFD for the optimal design method considering their distribution. In this paper, the optimal design means the most appropriate boundary conditions of the room among the conditions where the design target of indoor therm environment is achieved. Two step optimal indoor thermal environment design method is proposed. It includes the GA for searching the optimal indoor thermal environment design. To examine the performance of this method, the optimal design of hybrid ventilation system, which uses the natural cross ventilation and the radiation-cooling panel is conducted. The optimal design which satisfies the design target (thermal comfort, minimum cooling load, minimum vertical temperature difference) is found using two step optimal design method.

인공위성용 니켈-수소 축전지 충전전압 제한회로 구현 (NiH2 battery voltage limit circuit design for satellite)

  • 최영진;왕진석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 A
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    • pp.376-378
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    • 1995
  • A voltage-temperature limit circuit for the Ni-H2 battery is designed and analyzed for the maximum and the minimum voltage deviations at the worst case of the EOL(end of life). It is demonstrated that the magnitude of voltage deviations due to circuit device tolerances are kept less than 0.3v at the worst case. The maximum and the minimum battery voltages are simulated for the environmental temperature range of $0^{\circ}C-30^{\circ}C$ by using MATHCAD. They are 34.67v and 29.851v, respectively.

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Studies on the Seasonal Incidence of the Whitefly (Dialeuropora decempuncta Quaintance and Baker) Causing Leaf Curl on Mulberry in Relation to Abiotic Factors

  • Bandyopadhyay, U.K.;Sahu, P.K.;Raina, S.K.;Santhakumar, M.V.;Chakraborty, N.;Sen, S.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제1권1호
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    • pp.65-71
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    • 2000
  • A study was conducted to examine the relationship between abiotic factors and the population of white-fly (Dialeuropora decempuncta) in mulberry field. The study reveals that relationship between abiotic factors and the whitefly population is very much existent like other pests in other agricultural crops. Duration and time of distinct occurrence of whitefly in mulberry is influenced by the abiotic conditions of field. Abiotic parameters of previous month are more important in influencing the intensity of the pest than the current abiotic factors. Not all the abiotic factors are equally important but factors like minimum temperature, fluctuation in temperature during the days minimum relative humidity, fluctuation in relative humidity and rainfall are the major important lactors in influencing the intensity of the pest under consideration.

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The Observational Evidence for the Internal Excitation of Umbral Velocity Oscillations

  • Cho, Kyuhyoun;Chae, Jounchul
    • 천문학회보
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    • 제43권2호
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    • pp.47.2-47.2
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    • 2018
  • The umbral oscillations of velocity are commonly observed in the chromosphere of a sunspot. Their sources are considered to be either the external p-mode driving or the internal excitation by magnetoconvection. Even though the possibility of the p-mode driving has been often considered, the internal excitation has been rarely investigated. We report the observational evidence for the internal excitation obtained by analyzing velocity oscillations in the temperature minimum region of a sunspot umbra. The velocity oscillations in the temperature minimum region were determined from Fe I $5435{\AA}$ line data taken by the Fast Imaging Solar Spectrograph (FISS) of the 1.6 m Goode solar Telescope (GST) at the Big Bear Solar Observatory. As a result, we discovered 4 events of oscillations which appear to be internally excited. We analyze their characteristics and relation to photospheric features. Based on these results, we estimate the contribution of the internal excitation for umbral oscillations and discuss their importance.

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고온 초전도체 팬케이크 코일의 퀜치 해석 (Quench Analysis in HTS Pancake Coil)

  • 박차식;안태길;박경우;김도형;차귀수;서정식
    • 한국초전도ㆍ저온공학회논문지
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    • 제11권3호
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    • pp.6-9
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    • 2009
  • The thermal characteristics of quench propagation is a crucial problem for the stability of the superconductor. The objective of this study is to simulate the quench propagation with the variation of disturbance energy in Bi-2223/Ag HTS pancake coil. In this analysis, the temperature-time trace of a point away from heater was calculated under conditions of different quench energy. The critical disturbance energy between quench propagation and quench recovering was calculated, In addition, the minimum quench energy with different transport currents was obtained through the present simulation. These results are significant to the application of HTS.