• Title/Summary/Keyword: low humidity

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Canopy Microclimate of Water-Seeding Rice during Internode Elongation Period (담수직파 벼의 신장기 군락내 미기후 특성)

  • Yun, Jin-Il;Shin, Jin-Chul;Yun, Yong-Dae;Park, Eun-Woo;Cho, Seong-In;Hwang, Heon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.4
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    • pp.473-482
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    • 1997
  • Temperature, humidity and wetness duration were monitored for fully developed paddy rice canopies with 3 different structures induced by the seeding method(puddled-soil drill seeding, DS ; hand broadcasting, HB ; machine broadcasting, MB). Within-canopy air temperature averaged over "clear sky" hours during the study period(maximum tillering through heading) was lower than the screen temperature at a nearby standard weather station, especially in the night. The same trend was true for "overcast sky" hours except the diurnal distinction. Vapor pressure within the canopy was high during the daytime and low in the night, making the daytime deviation from outside the canopy more significant on clear days. Under the overcast sky, the canopy maintained a steady 5 to 10% higher vapor pressure than the outside regardless of day or night. Daily maximum temperature was observed to be higher within the canopies with more leaf mass, making MB the highest, HB the lowest, and DS in between. Relative humidity was over 90% in the night and dropped to 70% in the mid-afternoon, but vapor pressure within the canopy was highest at around 13:00 LST. Dew point depression was lowest and, combined with the temperature, the relative humidity was highest in HB. Mean period of wetting duration was in the order of DS>HB>MB, while the dew point depression was greatest in DS.

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Effects of MA Storage with Fine Holes For Red Chili Pepper and Red Bell Pepper Fruits (홍고추 및 홍피망의 미세공 MA저장 효과)

  • 이귀현;정천순
    • Food Science and Preservation
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    • v.8 no.2
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    • pp.125-130
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    • 2001
  • The effects of modified atmosphere(MA) storage for fresh red chili pepper and red bell pepper fruits were investigated with storing in polyethylene film with various fine holes. During the storage of the both pepper fruits, the weight loss, color change, mold emergence, and firmness were evaluated. The weight loss of pepper fruits packaged without holes on film was less than 3%, even though it was each 50% and 25% for non packaged red chili pepper and red bell pepper fruits. The rates of mold emergence of red chili pepper and red bell pepper fruits were reached to each 60% and 50% at the end of storage period as stored in film without holes. However, the rate of mold emergence of pepper fruits was lowered when fruits were stored in MA with low relative humidity (70∼80%). The color and firmness of pepper fruits were not much changed when fruits were stored in MA with high humidity.

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An Experimental Study of Environmental Effects on the Rolling Resistance of Bearings Coated by Soft Metallic Films (연금속 박막이 코팅된 베어링의 구름 저항 거동에 미치는 분위기의 영향에 대한 실험적 고찰)

  • 양승호;공호성;윤의성;김대은
    • Tribology and Lubricants
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    • v.14 no.3
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    • pp.1-6
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    • 1998
  • An experimental study was performed to discover the effect of environmental conditions on the rolling resistance behavior of pure silver and lead coated 52100 bearing steel. Pure silver and lead coatings were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed under vacuum, dry air and controlled humidity conditions. Results showed that agglomeration of particles were suppressed in vacuum environment and resulted in low and stable rolling resistance by shakedown phenomena. Also, humidity related closely to the agglomeration of particles and the rolling resistance after the failure of coated layer.

An Experimental Study of Environmental Effects on the Rolling Resistance of Bearing Surfaces Coated by Soft Metallic Films (연금속 박막이 코팅된 베어링 표면의 구름 저항 거동에 미치는 분위기의 영향에 대한 실험적 고찰)

  • 양승호;공호성;윤의성;김대은
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.47-54
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    • 1998
  • An experimental study was performed to discover the effect of environmental conditions on the rolling resistance behavior of pure silver and lead coated 52100 bearing steel. Pure silver and lead coating were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed under vacuum, dry air and controlled humidity conditions. Results showed that agglomeration of particles were prevented in vacuum environment and as it showed low and stable rolling resistance by shakedown phenomena. Also, humidity relates closely to the agglomeration of particles and increased the rolling resistance after the failure of coated layer.

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An Experimental Study on the Effect of Temperature and Humidity on the Pressure Change of the Bootstrap type Reservoir in the Aircraft (자체여압 형 항공기용 저장조의 온도 및 습도에 따른 내부압력 변화에 관한 실험적 연구)

  • Kim, Jung-Sik;Yu, Han-Sik;Park, Dong-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.5
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    • pp.170-175
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    • 2013
  • For this study, the domestically developed bootstrap reservoir of the aircraft is set up in accordance with the temperature and humidity conditions depicted on the qualification test, and the variation in the internal pressure of the bootstrap reservoir of the aircraft is examined. The study shows that the bootstrap reservoir has less variation in the internal pressure at room temperature than at low temperature($-40^{\circ}C$). As a result, the internal pressure can be maintained stably when the temperature of working fluid in the bootstrap reservoir and the atmosphere environment is over room temperature($25^{\circ}C$). Therefore the keeping of temperature above room temperature is very important to operate the bootstrap reservoir of the aircraft properly.

House dust mite fauna in western Anatolia, Turkey

  • Ciftci Ihsan Hakki;Cetinkaya Zafer;Atambay Metin;Kiyildi Nilay;Aycan Ozlem M.;Daldal Nilgun
    • Parasites, Hosts and Diseases
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    • v.44 no.3
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    • pp.259-264
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    • 2006
  • House dust mites play an important role in the pathogenesis of allergic diseases. Many factors may influence mite growth. The presence of mites is related to mean temperature and humidity as well as altitude. The aim of this study was to analyze the mite fauna in 5 regions of western Anatolia, Turkey, that have similar climatic properties with low mean temperature and humidity, but differ in altitude. During the period October-November 2004, house dust was collected from 290 homes in 5 different cities. House dust mites were isolated in 67 (23.1 %) of 290 samples. The family Pyroglyphidae (Astigmata) was present in all positive samples. This study suggests that the selected western Anatolian regions that share similar environmental conditions host similar dust mite populations.

Theoretical Analysis of a Recuperative Refrigeration Dehumidifier (열회수 냉각 제습기의 이론적 해석)

  • Kim, Dong-Seon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.1
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    • pp.48-54
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    • 2014
  • A refrigeration dehumidifier with a recuperative heat exchanger is theoretically analyzed. The recuperative heat exchanger is located between the two air streams from and to the dehumidifying coil, and reduces the sensible heat load in dehumidification process. A simple model is developed to predict performance of the dehumidifier. The model predicts that the recuperative heat exchanger is effective especially in the low humidity condition, where the sensible heat load is relatively large. It is predicted that, by adopting a recuperative heat exchanger, a maximum 30~110% increase in COP is possible for indoor air at $27^{\circ}C$, and 40~60% relative humidity.

The Breakdown Characteristics for Dry-Air with Humidity Variations (Dry-Air의 습도에 따른 절연파괴 특성)

  • Park, He-Rie;Kim, Young-Su;Choi, Eun-Hyuck;Park, Kwang-Seo;Kim, Lee-Kook;Park, Won-Zoo;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.238-240
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    • 2008
  • This paper gives a basic data of the breakdown characteristics of Dry-Air and air based on their dew point and humidity variations in experimental GIS model by applying AC voltage. The breakdown voltage of Dry-Air was increased as gap length had been increased. The characteristics of Dry-air which had low dew point were higher. In the case of air, the breakdown voltage curves were like Dry-Air' s. But the curves were slightly folded up and down because of impurities.

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ANN Modeling of a Gas Sensor

  • Baha, H.;Dibi, Z.
    • Journal of Electrical Engineering and Technology
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    • v.5 no.3
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    • pp.493-496
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    • 2010
  • At present, Metal Oxide gas Sensors (MOXs) are widely used in gas detection because of its advantages, including high sensitivity and low cost. However, MOX presents well-known problems, including lack of selectivity and environment effect, which has motivated studies on different measurement strategies and signal-processing algorithms. In this paper, we present an artificial neural network (ANN) that models an MOX sensor (TGS822) used in a dynamic environment. This model takes into account dependence in relative humidity and in gas nature. Using MATLAB interface in the design phase and optimization, the proposed model is implemented as a component in an electronic simulator library and accurately expressed the nonlinear character of the response and that its dependence on temperature and relative humidity were higher than gas nature.

Cloud Forecast using Numerical Weather Prediction (수치 예보를 이용한 구름 예보)

  • Kim, Young-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.3
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    • pp.57-62
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    • 2007
  • In this paper, we attempted to produce the cloud forecast that use the numerical weather prediction(NWP) MM5 for objective cloud forecast. We presented two methods for cloud forecast. One of them used total cloud mixing ratio registered to sum(synthesis) of cloud-water and cloud-ice grain mixing ratio those are variables related to cloud among NWP result data and the other method that used relative humidity. An experiment was carried out period from 23th to 24th July 2004. According to the sequence of comparing the derived cloud forecast data with the observed value, it was indicated that both of those have a practical use possibility as cloud forecast method. Specially in this Case study, cloud forecast method that use total cloud mixing ratio indicated good forecast availability to forecast of the low level clouds as well as middle and high level clouds.

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