• 제목/요약/키워드: effects of surface temperature

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식물의 온도 완화효과에 관한 기초적 연구 (A Quantitative Study on the Effect of Temperature Control by a Shade Tree and the Lawn Area)

  • 안계복;김기선
    • 한국조경학회지
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    • 제14권1호
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    • pp.1-13
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    • 1986
  • The purpose of this study is to investigate the effect of temperature control by a shade tree and the lawn area. In this investigation, we find out that artificial-lawn, concerte, and exposed soil are more higher temperature than covered with plant materials. The results of the measurement may to summerized as follows; 1) Low-temperature effects of zoysia japonica is more controlled by condition of growth than leaf length of grass. Surface temperature make 0.7$^{\circ}C$ difference between long grass (15cm), and short grass (5cm), but make 5$^{\circ}C$ difference between good growth grass (230/10$\textrm{cm}^2$) and bad growth grass (80/10$\textrm{cm}^2$). 2) The surface temperature of the lawn area is 40.5$^{\circ}C$ lower on a maxinum than that of the artificial lawn (July 28, 1985). During the day of summer, shade area under the shade tree is 0.9$^{\circ}C$ lower then lawn area surface temperature, 6.9$^{\circ}C$ lower than bad growth lawn, 10.3$^{\circ}C$ lower than exposed soil, and 18$^{\circ}C$ lower than concrete surface temperature. 3) Natural irrigation effect on the surface temperature fluctuation. But this effect is changed by compositions of ground materials and time-lapse. 4) Sunny day is more effective than cloud day. 5) In summer season, surface temperature make a difference compare to temperature of 0.5-1.5m height from ground : Surface temperature is 3.4$^{\circ}C$ lower at the lawn area (11 a.m.), 4.2$^{\circ}C$ lower at the shade area the shade tree, 12.7$^{\circ}C$ higher at the concrete area (3p.m.), 38.8$^{\circ}C$ higher at the artificial lawn (2p.m.) 6) According to compositions of ground materials and season have specific vertical temperature distribution curve. 7) In summer season, temperature distribution of 0.5-1.5m hight at the shade tree is 4.8-5.7$^{\circ}C$ lower than concrete area (noon-3p.m.)

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위성 및 AWS 자료를 이용한 지표면 피복 조건의 차이가 대구의 도시 열환경에 미치는 영향 (Effect of Difference of Land Cover Conditions on Urban Thermal Environment in Daegu Using Satellite and AWS Data)

  • 안지숙;김해동;김상우
    • 한국환경과학회지
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    • 제19권3호
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    • pp.281-293
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    • 2010
  • The present study explores time and spatial thermal environment for Daegu, which is a city built on a basin area, according to varying land cover conditions of the earth's surface by analyzing data derived from meteorological observation and satellite images. The study has classified land use by utilizing MODIS satellite images and analyzed land surface temperature. Also, by using data acquired from automatic weather system, the study has evaluated the effects of atmospheric heating caused by city pavements by analyzing the sensible heat flux between the city's land surface and the atmosphere. The results are as follows. 1) Classification of land use in the Daegu area shows 46.64% of urban and built-up area, 1.39% of watersides, 35.19% of forest, 11.43% of crops, and 5.37% grasslands. 2) During the weekdays throughout the year, the land surface temperature was high for Dalseogu, Bukgu, and Seogu regions where industrial complexes could be found. Comparatively, lower temperature could be observed in the woodlands. 3) While the land surface temperature displayed the effects of pushing air upwards during the weekdays in urban areas, the reverse was true for forest regions. During the night, the temperature did not exert any significant influence on air movement.

적외선 열화상을 이용한 건축외장재의 일사표면온도와 흡수율 추정에 관한 실험적 연구 (An Experimental Study on the Estimation of Sol-air Temperature and Absorptance in Building Exterior Materials by Using the Infrared Image)

  • 박사근;장길수;송민정;신 훈
    • KIEAE Journal
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    • 제6권4호
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    • pp.33-39
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    • 2006
  • This study aims to investigate the method to reduce the surface temperature caused by insolation. To achieve this goal, surface temperature of building is measured and the effects of exterior material's color and brilliance were checked with infrared imaging. And also, exterior material's absorptances due to outdoor surface heat transfer coefficients were measured. After surface temperature measurement of 37 specimen of 5 categories, the temperature is the highest on wood($53.62^{\circ}C$) and panel($52.05^{\circ}C$). Dryvit, stone, brick is the rating of order. For exterior material's absorptances, panel(0.883) and wood(0.868) were high and Dryvit, stone, brick follows wood and panel.

아연의 가열온도와 표면 거칠기가 원적외선 복사량에 미치는 영향 (Effects of Temperature and Surface Roughness of Zinc on the Far-Infrared Ray Emissivity)

  • 장충근;임진석;김원사
    • 한국광물학회지
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    • 제12권2호
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    • pp.96-100
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    • 1999
  • Effects of surface conditions (temperature and roughness) of test specimens, when measuring emissive power of far-infrared ray, have been investigated using FT-IR spectrometer. Element metal zinc (Zn) was selected in this study as representative specimen of materials consisting of simple element. The zinc specimens were heated to four temperatures, i.e., 333K, 353K, .373K, and also their surface was finished with SiC abrasive papers of 100, 220, 360, 400, 600, 800, and 1000 mesh in size. The results shows that the emissive power (W/㎡) of the far-infrared ray increases with temperature for a given roughness and its relationship may be expressed by the following equations: Yη=1.0=0.142$.$T-0.937 for η=1.0, and Yη=10=0.016$.$T-1.286 for η=10. The emissive power is also known to increase with surface roughness for a given temperature. Their relationship can be represented by the following equations: YT=313K=0.234$.$$\ell$n(η)+3.53, at 313K, YT=353K=0.234$.$$\ell$n(η)+4.02 at 353K and YT=393K=0.243$.$$\ell$n(η)+4.62 at 393K.

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Effects of Chemical Etching with Sulfuric Acid on Glass Surface

  • Jang, H.K.;Chung, Y.L.;S.W.Whangbo;C.N.Whang;Lee, S.J.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.165-165
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    • 2000
  • Glass slides were chemically etched with sulfuric acid using five different methods. we investigated the effects of the chemical etching conditions on such properties as chemical composition, surface roughness, and the thermal stability of the glass. Sodium and carbon atoms in the surface of the glass are effectively eliminated by chemical etching with sulfuric acid. The glass slides were boiled for 30 min in 95% sulfuric acid and were depth profiled at room temperature with X-ray photoelectron spectroscopy (XPS), the Na ls signal was not detected in the detection limit of XPS. Surface morphology of the glass was very different depending on the concentration of sulfuric acid. The surface of the glass etched with 50% sulfuric acid was rougher than that of glass etched with 95% sulfuric acid. The sodium concentration of the glass boiled for 30 min in 95% sulfuric acid was nearly zero at the glass surface, and the sodium composition changed very little with annealing temperatures up to 35$0^{\circ}C$ in a vacuum environment. However the sulfur concentration at the glass surface due to the sulfuric acid increased with increasing temperature.

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Micro-scale Thermal Sensor Manufacturing and Verification for Measurement of Temperature on Wafer Surface

  • Kim, JunYoung;Jang, KyungMin;Joo, KangWo;Kim, KwangSun
    • 반도체디스플레이기술학회지
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    • 제12권4호
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    • pp.39-44
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    • 2013
  • In the semiconductor heat-treatment process, the temperature uniformity determines the film quality of a wafer. This film quality effects on the overall yield rate. The heat transfer of the wafer surface in the heat-treatment process equipment is occurred by convection and radiation complexly. Because of this, there is the nonlinearity between the wafer temperature and reactor. Therefore, the accurate prediction of temperature on the wafer surface is difficult without the direct measurement. The thermal camera and the T/C wafer are general ways to confirm the temperature uniformity on the heat-treatment process. As above ways have limit to measure the temperature in the precise domain under the micro-scale. In this study, we developed the thin film type temperature sensor using the MEMS technology to establish the system which can measure the temperature under the micro-scale. We combined the experiment and numerical analysis to verify and calibrate the system. Finally, we measured the temperature on the wafer surface on the semiconductor process using the developed system, and confirmed the temperature variation by comparison with the commercial T/C wafer.

Herschel-Bulkley 모델을 이용한 그리스 열탄성유체윤활 문제의 수치해석 (A numerical analysis of grease thermal elastohydrodynamic lubrication problem using Herschel-Bulkley model)

  • 유진규;김경웅
    • Tribology and Lubricants
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    • 제11권3호
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    • pp.31-39
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    • 1995
  • Grease thermal elastohydrodynamic lubrication (TEHL) problems of line contacts are analyzed numerically. The effects of temperature and rheological paraineters on grease TEHL are investigated using the Herschel-Bulkley model as a theological model of greases. The pressure distribution, the shape of grease film, mean film temperature and surface temperature of solid wall in line contacts are obtained. It is found that thermal effects on the minimum film thickness become remarkable at high rolling speeds. The effect of yield stress of Herschel-Bulkley model on minimum film thickness is negligible, while the theological index and viscosity parameter have significant effects on minimum film thickness.

증발억제법에 의한 수온 및 지온상승효과에 관한 연구

  • 김광식
    • 물과 미래
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    • 제5권2호
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    • pp.6-16
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    • 1972
  • It has been well studied and known that the yields from the rice fields irrigated by the cold water such as the water directly flowing in from mountain valleies, underground water and subground water are largely influenced by the water temperature. However, the best method of raising water temperature has not yet been established. This is because there are some essentially difficult problems associated. When we examine the effects of $1^{\circ}C$ rise in the water temperature under natural condition on rice growing, the necessity of this line of study is verified. The results of Mihara's study show that rice bears its fruits at the water temperature above $19^{\circ}C$ and the difference of $1^{\circ}C$ in the range of $19^{\circ}C$ to $22^{\circ}C$ can produce the 20% of difference in yields. Because of these facts, most farmers have made use of water temperature raising ponds, zigzag waterways and shelter belts. But the most important factor in raising water temperature has been found to be the heat loss due to evaporation. Recently, a good deal of experiment on raising water temperature and soil temperature by reducing the evaporation are being carried out all over the world. The reduction of evaporation does not only reduce heat loss, from the surface but also reduce the loss of water. Present study is aimed to determine the efficiency of different chemicals by which monomolecular films are formed over different surfaces such as water surface, soil surface and the surface of plant leaves with a purpose of preventing the transpiration, and aimed to observe the effects of the temperature rise and its influence on growing state as well as the durability of the plants under drought condition.

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촉매벽 효과를 고려한 무딘 물체 주위의 열화학적 비평형 유동에 대한 수치적 연구 (NUMERICAL SIMULATION OF THERMOCHEMICAL NON-EQUILIBRIUM FLOW AROUND BLUNT BODIES CONSIDERING CATALYTIC WALL EFFECTS)

  • 김재원;권오준
    • 한국전산유체공학회지
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    • 제18권3호
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    • pp.87-93
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    • 2013
  • A computational study has been performed to examine the effects of catalytic walls on the stagnation region heat transfer. The boundary conditions for none, finite, and fully catalytic walls have been incorporated into a multi-block compressible Navier-Stokes solver. In the present study, both chemical and thermal non-equilibrium effects were included. The flows over a blunt body model were simulated by varying surface catalytic recombination rates. A full range of catalycities was explored in the context of a constant wall temperature assumption. Detailed information on species concentrations, temperature, and surface heat flux are presented. Comparison with available flight data of surface heat flux is also made.

우리나라 곡물류 생산량에 기상요소의 영향에 관한 연구 (Study on Effects of Meteorological Elements in the Grain Production of Korea)

  • 장영재;이중우;박종길;박흥재
    • 한국환경과학회지
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    • 제24권3호
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    • pp.281-290
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    • 2015
  • Recent climate change has led to fluctuations in agricultural production, and as a result national food supply has become an important strategic factor in economic policy. As such, in this study, panel data was collected to analyze the effects of seven meteorological elements on the production of five types of grain with error component panel data regression method following the test results of LM tests, Hausman test. The key factors affecting the production of rice were average temperature, average relative humidity and average ground surface temperature. The fluctuations in the other four grains types are not well explained by meterological elements. For other grains and beans, only average temperature and time (year) affect the production of other grains while average temperature, ground surface temperature, and time (year) influence the production of beans. For barley and millet, only average temperature positively affects the production of barley while ground surface temperature and time (year) negatively influence the production of millet. The implications of this study are as follow. First, it was confirmed that the meteorological elements have profound effects on the rice production. Second, when compared to existing studies, this study was not limited to rice but encompassed all five types of grains and went beyond other studies that were limited to temperature and rainfall to include various meteorological elements.