• 제목/요약/키워드: Various temperature

검색결과 12,876건 처리시간 0.044초

Simple modeling to explore temperatures, heated temperature, and Kappa values of a current sheet observation

  • Lee, Jin-Yi;Raymond, John C.;Reeves, Katharine K.;Shen, Chengcai;Kahler, Stephen;Moon, Yong-Jae;Kim, Yeon-Han
    • 천문학회보
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    • 제46권2호
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    • pp.79.2-79.2
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    • 2021
  • We explore the range of possibilities of temperatures, heated temperature, and Kappa values of a current sheet observation on 2017 September 10. First, we construct a grid model with rapid heating (Theat) and various Kappa (κ) values. We assume a simple density model and use adiabatic cooling to set the temperature during expansion. Next, we calculate the ion fractions using a time-dependent ionization model with adiabatic cooling and various Kappa values. The calculated ion fractions are used to simulate the DNs of the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory. Then, we explore the possible range of the temperatures and Kappa values, comparing the simulated images with the observations. Finally, we discuss the range of the heated temperature and Kappa values and whether the result of this study suggests continuous heating of the current sheet plasma during the expansion.

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축열식 고온공기 연소시스템에 대한 실험적 연구 (Experimental Study on High Temperature Air Regenerative Combustion System)

  • 양병옥;임인권
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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    • pp.189-200
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    • 1999
  • Combustion characteristics of a regenerative combustor for high temperature air combustion have experimentally studied. Temperature measurement on regenerative ceramic material and combustor has been carried out with changing equivalence ratio at constant turn-over period. Stable and unstable combustion region have been found and also detailed averaged temperature profile with respect to various air flow conditions have been obtained.

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극저온 물성을 고러한 콘크리트 구조물의 비선형 해석 (Nonlinear Analysis of Concrete Structure at Extremely Low Temperature)

  • 곽효경;송종영;이병국;이광모
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
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    • pp.174-181
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    • 2000
  • A brief review of previous studies on the behaviour of concrete at extremely low temperature is presented in this paper. In addition, to describe temperature dependent behaviour of concrete, simple piecewise linear stress-strain relation is introduced. The proposed curve shows good agreement with experimental stress-strain curves at various temperature conditions. Moreover, numerical analyses for two PC beams are conducted to verify the influence of extremely low temperature to the structural behaviour.

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PIC를 이용한 백신 보관고의 온도제어 기법에 관한 연구 (Study of a Temperature Control Method of Vaccine Storage-Box with PIC)

  • 윤형상;차인수;양기옥
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.145-149
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    • 2001
  • This paper did so that may can establish optimum temperature according to kind of vaccine and digitalized various action situations using PIC 16C74A-04A/SP. Also, PID Algorithm Controller designed to maintain optimum temperature using PIC. Begin to operating system after temperature setting, reached in optimum storage temperature within 30 minutes.

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이중관 구조 박막형 순간온도 프로브의 응답성에 관한 연구 (A Study on the Responsibility of Thin film instantaneous surface temperature probe of a Dual-pipe structure)

  • 최석렬;박경석
    • 한국연소학회:학술대회논문집
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    • 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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    • pp.237-242
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    • 2003
  • The measurement study of instantaneous temperature at combustion chamber wall and the temperature of combustion gas has been under lots of research and development to conclude the temperature process in internal combustion engine for combustion characteristics analysis. The measurement with fast responsibility should be used for temperature measurement inside combustion chamber wall since temperature of wall changes, due to the various gas temperature, irregularly during the combustion. Therefore, thin film instantaneous surface temperature probe, which characterizes the fastest and the most accurate responsibility among contact typed temperature measurement, was used for the experiments. This new thin film instantaneous surface temperature probe improved the problems of noise and durability. The optimal coating thickness of thin film instantaneous surface temperature probe was proven to be $10{\mu}m$ for the best responsibility and durability. It also allowed the stable temperature measurement be taken up to $1,200^{\circ}C$ and proven to be read possibly from the combustion chamber wall.

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강제 재생 방식 DPF 내부의 온도 분포 특성에 관한 수치해석 (Numerical Analysis on the Characteristics of Temperature Distribution in an Active Regeneration DPF Type)

  • 박성천;이한성
    • 한국기계기술학회지
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    • 제13권2호
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    • pp.55-61
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    • 2011
  • This study analyzed on the characteristics of temperature distribution in an active regeneration DPF using computer simulation. In order to verify the boundary condition of analysis, results of temperature distribution in DPF are compared between experimental and computer simulation. Using this boundary condition, temperature distribution and filter's durability in DPF analyzed according to various operating conditions. The results of computational analysis are agreed well with experimental ones from the tendency of temperature distribution of axis and radius direction. The temperature increases and the axial temperature gradients in DPF according to velocity of exhaust gas are lowered as the high velocity of exhaust gas. But the temperature gradients of radius direction at exit side in DPF are grown as the high velocity of exhaust gas. The results according to inlet temperature of exhaust gas show that the increase ratios of temperature in DPF are grown as the high temperature of exhaust gas.

Influence of Temperature on Microsporidian Multiplication and Spore Production in Various Tissues of Silkworm (Bombyx mori L.) During Larval Development

  • Mohanan N. Madana;Krishnan N.;Mitra P.;Das K.K.;Saratchandra B.;Haldar D.P.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제12권2호
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    • pp.87-93
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    • 2006
  • Multiplication and spore production of three microsporidia viz., Nosema bombycis, Nosema sp. 1 and Nosema sp. 2 in fifth instar larval tissues of silkworm, Bombyx mori L. in two seasons with distinct temperature regimes were studied. Nosema sp. 2 produced significantly (P < 0.01) higher number of spores in various tissues. Among the tissues, spore production was highest in silk gland, followed by fat body and gut. Spore production was significantly (P < 0.01) higher in season-II (Average temperature $29.4{\pm}1.1^{\circ}C$). Maximum spore production was observed 25 days post inoculation (p. i.) in season-I (Average temperature $18.9{\pm}1.1^{\circ}C$), whereas in season-II, it was 14 days p. i. In season-I, spore production was low up to 21 days p. i., then increased sharply. In season-II, there was a steady increase in spore production. The results indicate that the microsporidian multiplication is tissue specific and extremely sensitive to temperature at which the host is reared. It also reveals that, silk gland, fat body and gut are the most appropriate tissues for microscopic identification of microsporidia in the larval stage.

Vibration analysis of carbon nanotubes with multiple cracks in thermal environment

  • Ebrahimi, Farzad;Mahmoodi, Fatemeh
    • Advances in nano research
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    • 제6권1호
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    • pp.57-80
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    • 2018
  • In this study, the thermal loading effect on free vibration characteristics of carbon nanotubes (CNTs) with multiple cracks is studied. Various boundary conditions for nanotube are taken in to account. In order to take the small scale effect, the nonlocal elasticity of Eringen is employed in the framework of Euler-Bernoulli beam theory. This theory states that the stress at a reference point is a function of strains at all points in the continuum. A cracked nanotube is assumed to be consisted of two segments that are connected by a rotational spring which is located in the position of the cracked section. Hamilton's principle is used to achieve the governing equations. Influences of the nonlocal parameter, crack severity, temperature change and the number of cracks on the system frequencies are investigated. Also, it is found that at room or lower temperature the natural frequency for CNT decreases as the value of temperature change increases, while at temperature higher than room temperature the natural frequency of CNT increases as the value of temperature change increases. Various boundary conditions have been applied to the nanotube.

열간단조시 금형과 소재간 계면열전달계수에 관한 연구 (A Study of Interface Heat Transfer Coefficient Between Die and Workpiece for Hot Forging)

  • 권진욱;이정환;이영선;권용남;배원병
    • 소성∙가공
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    • 제14권5호
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    • pp.460-465
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    • 2005
  • The temperature difference between die and workpiece has been frequently caused to various surface defects. The distribution and change for the temperature of forged part should be analyzed to prevent the generation of various defects related with the temperature. The surface temperature changes were affected with the interface heat transfer coefficient. Therefore, the coefficient is necessary to predict the temperature changes of die and workpiece. In this study, the experimental and FE analysis were performed to evaluate the coefficient with a function of pressure, temperature, material, and etc. The closed die upsetting was used to measure the coefficient on pressure over the flow stress. AISI1045, A16061, and Cu-OFHC were used to analyze the effect of material. The coefficient was increased with step-up of pressure between die and workpiece. And, A16061 was larger than that of the AISI1045 and Cu-OFHC up to the five times.

Sorption of chlorophenols on geotextile of the geosynthetic clay liners

  • Ahari, M'hamed;Touze-Foltz, Nathalie;Mazeas, Laurent
    • Environmental Engineering Research
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    • 제25권2호
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    • pp.163-170
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    • 2020
  • Knowledge of organic micropollutant transfers in barrier seal materials from waste storage facilities is limited to volatile organic compounds and phenolic compounds at ambient temperature. This study focused on the sorption of chlorophenols (CPs) from various geotextiles from clay geosynthetics under the influence of temperature. Also to study the impact of the polarity or the amount of CPs adsorbed on geotextiles with the partition coefficient. The effect of various parameters such as contact time, effect of temperature, initial CPs concentration and adsorbent dosage has been carried out in this study. The result obtained is non-linear and the data was calculated for affinity with Freundlich isotherm model. An important observation is that the amount of CPs sorbed on geotextiles increases with a growing number of chlorine atoms, ie increases with the partition coefficient (log Kow). During this study, a decrease in adsorbent properties was observed with the rise in temperature from 23℃ to 55℃. The partitioning coefficients for CPs examined range are from 2.4 (R2 = 0.86) to 8.4 mL/g (R2 = 0.90). Among the CPs studied, the highest adsorbed quantity was observed for pentachlorophenol with 0.052 g/g at 23℃, this quantity will decrease with the increase in temperature.