• Title/Summary/Keyword: TEMPERATURE

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도시공원의 기온에 영향을 미치는 요인 (Factors Affecting Temperature of Urban Parks)

  • 윤용한;송태갑
    • 한국조경학회지
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    • 제28권2호
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    • pp.39-48
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    • 2000
  • The purpose of this study is to investigate the factors affecting temperature of urban parks to grasp the relationship between the land coverage in open space as well as the forest condition and decreasing city temperature by difference of purposed are. Futhermore, this research interpreted the relationship between wind direction, air temperature, the land coverage of the green space, the number of tree, green volume, height of tree and the mitigation of city temperature with the revolution analysis. The result of this study is that cool air in open space move leeward and decreasing city temperature is influenced by the difference of the land coverage in open space. Specifically, in order of the arbo $r_{-a}$rbor in the forest zone, the increase of the number of trees was related with temperature surrounding significantly. This study found that the use possibility of the green volume was recognized as the index of the green volume relative to air temperature surrounding. Green space of the city control area is more effective decreasing temperature than that of housing zone.

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동적인 온도 보정 방법에 의한 전기 전도도의 측정 (Measurement of electrical conductivity by a dynamic temperature compensation method)

  • 차용대;윤길원
    • 센서학회지
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    • 제17권3호
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    • pp.223-228
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    • 2008
  • A more accurate method of measuring the electrical conductivity (L) of solutions was developed by applying dynamic temperature compensation for measurement of L. Temperature changes of a sample were induced by a heater probe and the changes in L per unit temperature were measured. An equation for L with respect to temperature change was developed and L at the standard temperature ($25^{\circ}C$) was computed. Based on our proposed method, it is possible to have temperature compensation without having the temperature coefficients in advance.

An Isothermal Temperature Source with a Large Surface Area using the Metal-Etched Microwick-Inserted Vapor Chamber Heat Spreader

  • Go, Jeong-Sang;Kim, Kyung-Chun
    • Journal of Mechanical Science and Technology
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    • 제18권4호
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    • pp.681-688
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    • 2004
  • For use of the thermal cycle of the biochemical fluid sample, the isothermal temperature source with a large surface area was designed, fabricated and its thermal characterization was experimentally evaluated. The comprehensive overview of the technology trend on the temperature control devices was detailed. The large surface area isothermal temperature source was realized by using the vapor chamber heat spreader. The cost-effectiveness and simple manufacturing process were achieved by using the metal-etched wick structure. The temperature distribution was quantitatively investigated by using IR temperature imaging system at equivalent temperatures to the PCR thermal cycle. The standard deviation was measured to be within 0.7$^{\circ}C$ for each temperature cycle. This concludes that the presented isothermal temperature source enables no temperature gradient inside bio-sample fluid. Furthermore it can be applied to the cooling of the electronic devices due to its slimness and low thermal spreading resistance.

동축류 버너에서 생성된 부분 예혼합 화염을 이용한 화염 온도 측정 검정원 연구 (Study on the partially premixed flames produced by a coflow burner as temperature calibration source)

  • 박철웅;한재원;신현동
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제21회 KOSCO SYMPOSIUM 논문집
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    • pp.160-167
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    • 2000
  • We investigated a uniform temperature zone, produced by double flame structure of a coflow CH4/air partially premixed flame, to be used as a temperature calibration source for laser diagnostics. A broadband N2 CARS(coherent anti-Stokes Raman spectroscopy) system with a modeless laser was used for temperature measurement. When the stoichiometric ratio was 1.5, we found the uniform temperature zone in radial direction of the flame of which the averaged temperature was 2110 K with standard deviation 24 K. In the stoichiometric ratio range between 2.0 and 2.5, we found very stable temperature-varying zones in vertical direction at the center of the flame. The size of the zone was approximately 15 mm and it covered a temperature range from 300 K to 1900 K. We also suggest that this zone can be used as a calibration source for 2-D PLIF(planar laser induced flurescence) temperature measurement.

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가스터빈 연소기내의 고온공기 분무연소 해석 (Spray combustion with high temperature air in a Gas Turbine Combustor)

  • 조상필;김호영;박심수
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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    • pp.192-198
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    • 2004
  • A numerical study was conducted to determine the effects of high temperature air, including equivalent ratio on flow field, temperature, evaporation, and overall temperature distribution in gas turbine combustor. A sector model of a typical wall jet can combustor, featuring introduction of primary air and dilution air via wall jet, was used in calculations. Flow field and temperature distribution were analyzed. Operating conditions such as inlet temperature and overall equivalent ratio were varied from 373 to 1300 K, and from 0.3 to 0.6, respectively, while any other operating conditions were fixed. The RNG ${\kappa}-{\varepsilon}$ model and eddy breakup model were used for turbulence and combustion model respectively. It was found that the increase with the inlet air temperature, velocity in the combustor is accelerated and evaporation of liquid fuel is not affected in primary zone, high temperature inlet air enhances the evaporation and improves overall temperature distribution factor.

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SUP9강의 저온피로크랙 전파특성에 관한 연구 (A Study on the Fatigue Crack Propagation Characteristics for SUP9 Steel at Low Temperature)

  • 박경동;박상오
    • 한국해양공학회지
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    • 제16권5호
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    • pp.80-87
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    • 2002
  • In this study, CT specimens were prepared from spring steel(SUP9) which was used in suspension of automobile for room temperature and low temperature service. We got the following characteristics from fatigue crack growth test carried out in the environment of room temperature and low temperature at $25^{\circ}C$, ­3$0^{\circ}C$, ­5$0^{\circ}C$, ­7$0^{\circ}C$ and ­10$0^{\circ}C$ in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range ΔK in the stable of fatigue crack growth (Region II) was decreased in proportion to descend temperature. It is assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

배전용 몰드변압기에 대한 상승 온도 분포 예측 (Prediction of A Rise in Temperature Distribution of Mold Transformer for Power Distribution System)

  • 이정근;김지호;이향범
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.391-394
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    • 2009
  • In this paper, achieved rise temperature distribution about degradation phenomenon of 2 MVA distribution mold transformer using finite element method (FEM). Usually, life of transformer is depended on temperature distribution of specification region than thermal special quality of transformer interior. Specially, life of transformer by decline of dielectric strength decreases rapidly in case rise by strangeness transformer interior hot spot temperature value permits. Because calculating high-voltage winding and low-voltage winding of mold transformer and Joule's loss of core for improvement these life, forecasted heat source, and high-voltage winding and low-voltage winding of mold transformer and rise temperature distribution of core for supply of electric power and temperature distribution of highest point on the basis of the result Also, calculated temperature rise limit of mold transformer and permission maximum temperature using analysis by electron miracle heat source alculate and forecasted rise temperature distribution by heat source of thermal analysis with calculated result.

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The Practical Method and Experimental Verification of Temperature Estimation in the Permanent Magnet of Electric Machine

  • Kang, Kyongho;Yu, Sukjin;Lee, Geunho;Lee, Byeong-Hwa
    • Journal of Magnetics
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    • 제20권4호
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    • pp.421-426
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    • 2015
  • This paper presents a practical method for estimation of average temperature in the permanent magnet (PM) of electric machine by using finite element analysis (FEA) and dynamo load experiment. First of all, the temperature effect of PM to the torque has been employed by FEA in order to evaluate the Temperature-Torque characteristic curve. The 1st order polynomial equation which is torque attenuation coefficient is derived by the FEA result of the Temperature-Torque curve. Next, torque saturation test with constant current condition is performed by dynamo load experiment. Then, the temperature trend can be estimated by adding the initial starting temperature using the torque attenuation coefficient and torque saturation curve. Lastly, estimated temperature is validated by infrared thermometer which measures temperature of PM surface. The comparison between the estimated result and experimental result gives a good agreement within a deviation of maximum $8^{\circ}C$.

Changes in Skin Temperature and Physiological Reactions in Murrah Buffalo During Solar Exposure in Summer

  • Das, S.K.;Upadhyay, R.C.;Madan, M.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제10권5호
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    • pp.478-483
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    • 1997
  • Six adult female Murrah buffaloes of about 12 years were exposed to solar radiation during summer when minimum and maximum ambient temperatures were 27.1 and $44.1^{\circ}C$, respectively. The skin surface temperature at forehead, middle pinna, neck, rump, foreleg, hind legs were recorded using non-contact temperature measuring instrument and respiration rate and rectal temperature were measured throughout the 24 hours starting from 6:30 AM. The diurnal fluctuations and temperature gradients have been reported for buffaloes. During summer when ambient temperature and solar radiation was maximum, adult buffaloes were not able to maintain their thermal balance even after increasing the pulmonary frequency 5 - 6 times. The changes in skin temperature at various sites indicate that the temperature of skin surface not only varies in relation to exposure but also due to water diffusion and evaporation.

고구마의 저온증자 및 고온증자에 의한 공업적 규모의 주정발효 (Large Scale of Ethanol Fermentation from Sweet Potato Cooked at Low and High Temperature)

  • 유병호;김운식;김성두;최명호;남기두;하미숙
    • 한국미생물·생명공학회지
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    • 제14권3호
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    • pp.233-237
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    • 1986
  • 저온증자법에 의한 고구마의 에탄을 발효를 고온증자법과 비교하여 그 가능성을 검토하였다. 고구마를 분쇄하여 20메쉬체를 80% 통과시킨 분쇄물도 저온증자에 의한 에탄올의 생성량은 66.0g/$\ell$-68.1g/$\ell$고온증자(124$^{\circ}C$, 60분간)의 64.3g/$\ell$보다 높았으며 발효수율도 저온증자가 82.25%-84.8%로 고온증자의 82.2%보다 좋은 결과를 얻었다.

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