• Title/Summary/Keyword: temperature and humidity variation

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Characteristics of Meteorological Environment Variation Before and After Construction of Nak-dong River Estuary Barrage (낙동강 하구둑 건설 전·후의 기상환경 변화 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Impact Assessment
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    • v.14 no.3
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    • pp.135-145
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    • 2005
  • This study was conducted to investigate the characteristics of meteorological environment variation before and after construction of Nak-dong river estuary barrage. We used meteorological data(air temperature, precipitation, relative humidity, visibility, wind) at Gimhae airport meteorological station. The construction of river estuary barrage can change climate at the neighboring districts and influence human's health and vegetable. The construction of Nakdong river estuary barrage brought rise of temperature, decrease of relative humidity and increase of poor visibility frequency.

Influence of Temperature and Relative Humidity in Infection of Nosema bombycis (Microsporidia: Nosematidae) and Cross-infection of N. mylitta on Growth and Development of Mulberry Silkworm, Bombyx mori

  • Chakrabarti, Satadal;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.173-180
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    • 2008
  • The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

A study on the characteristics of environmental factors of granite dome models with different envelope structures in winter (외피 유형별 석재 모형돔의 동절기 환경 특성에 관한 연구)

  • 공성훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.5
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    • pp.642-646
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    • 1999
  • Factors governing the rate of heat exchange comprise the air temperature, the speed of air movement, relative humidity, and relation indoors. Recently, there are many researches on the transient analysis of indoor environmental factors such as the dry bulb temperature, relative humidity and air velocity in miniature models. The purpose of this study is to measure the environmental factors and to analyze and evaluate the characteristics of indoor environment with the different envelope structures using a granite dome model. According to the variation of humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

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A Study on the Variation of Physiology Signals based on EEG with Humidity (습도 변화에 따른 뇌파 기반 생체신호 변화에 관한 연구)

  • Kim, Myung-Ho;Kim, Jung-Min
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.1
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    • pp.50-55
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    • 2013
  • Subjects with 0.7[clo]'s amount of clothing were estimated on their thermal comfort, concentrativeness, heart rate variability, stress and fatigue degree when given variation in relative humidity to 30, 40, 50, 60, 70, and 80[RH%], in an environmental test room of temperature 25[$^{\circ}C$], illumination 1000[lux] and air velocity 0.02[m/sec], by using EEG, learning ability and HRV. At the result, it was at 50~60[RH%] of relative humidity that subject's thermal comfort and concentrativeness were at the highest while stress were at the lowest, and it was at 60[RH%] of relative humidity that heart rate variability was most stabilized. It was found that when temperature and humidity of the environmental test room are at 25[$^{\circ}C$] and 50~60[RH%], subject's productivity and psychological state are least affected.

Investigation of Internal Temperature and Relative Humidity of Concrete Immediately After Mix and Placement (양생직후 초기재령의 콘크리트 내부 온도와 상대습도의 측정 및 분석)

  • Park, Cheol-Woo;Park, Young-Hoon;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1065-1068
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    • 2008
  • Concrete is still one most common construction materials even in railway structures. As structures become massive and mega-sized, the importance of early age concrete quality control becomes more significant. Among various factors, relative humidity and temperature are the primary factors governing the early age quality. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.

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Theoretical and Experimental Considerations of Thermal Humidity Characteristics

  • Choi, Seok-Weon;Cho, Ju-Hyeong;Seo, Hee-Jun;Lee, Sang-Seol
    • International Journal of Aeronautical and Space Sciences
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    • v.3 no.1
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    • pp.9-18
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    • 2002
  • Thermal humidity characteristics were considered theoretically and experimentally. A Simply well-fitted correlation of a saturated vapor pressure-temperature curve of water was introduced based on Antoine equation to make theoretical prediction of relative humidity according to temperature variation. Characteristics of dew point were also examined theoretically and its relation with temperature and humidity was evaluated. The exact mass of water vapor in a specified humidity and temperature condition was estimated to provide useful insight into the idea about how much amount of water corresponds to a specified humidity and temperature condition in a confined system. A simple but well-fitting model of dehumidification process was introduced to anticipate the trend of relative humidity level during GN2(gaseous nitrogen) purge process in a humidity chamber. Well-suitedness of this model was also verified by comparison with experimental data. The overall appearance and specification of two thermal humidity chambers were introduced which were used to perform various thermal humidity tests in order to yield useful data necessary to support validity of theoretical models.

A study on indoor environmental elements of the granite model dome in different envelope materials during summer season (하절기, 석재 모형돔의 외피 유형별 실내환경 요소에 관한 연구)

  • 공성훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.6
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    • pp.898-902
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    • 1999
  • During summer season, the weather condition of Korea is hot and humid. So humidity elements are very important relating to building envelope condition. The purpose of this investigation is to measure and analyze characteristics of summer's environmental elements such as relative humidity, dry bulb temperature and air velocity in the clay/cement envelope materials using a granite dome model. According to the variation of exterior humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

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Gas Detecting Characteristics Using Catalytic Combustion Type Gas Sensor (접촉연소식 가스 센서를 이용한 감도특성)

  • Yoon, Hun-Ju;Ko, Keel-Young;Lee, Jong-Pil;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.773-777
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    • 2002
  • In this study, we analyzed the LPG and LNG sensitivity measurement and voltage variation using catalytic type gas sensor characteristics in catalytic combustion type gas detecter sensors. gas detector shall operate as intended when exposed for 24 hours to air having a relative humidity of 0~85 percent at a temperature of $20[{\mu}m]$ and humidity of 45 percent at a temperature of $-10{\sim}40[^{\circ}C]$ the gas detecter sensors are to be subjected to operation for 210 days in an area that has been detemined to be equivalent to a typical residential atmosphere with an air velocity of 50 [cm/sec]. The source of energy for a gas detector sensors employing a supplementary basic circuit is energized from a separate source of supply direct applied voltage 2.1[V], 2.2[V], 2.3[V]. As a result, it was confirmed that the relative humidity and temperature by regression each analysis, compared to the LPG characteristic graph and methane characteristics graph by a relative humidity of 0 ~ 85 [%] at a temperature range of $-10{\sim}40[^{\circ}C]$ show a similar linear pattern on the whore.

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The temperature and humidity variation along the width of greenhouse with Pad & Fan system (PAD & FAN 시스템에 대한 온실폭방향의 온. 습도 변화)

  • 이종원;이석건;이현우;김란숙;최상환
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.262-268
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    • 1998
  • This study were performed to find the cooling effect and to provide design data during summer season. for the Pad & Fan system of Venlo type greenhouse. The temperature and humidity variation along the greenhouse width and wind velocity in the greenhouse were surveyed. Also, the influence of shading on the cooling effect were analyzed. While Pad & Fan system were operated, the temperature, humidity and wind velocity in greenhouse were different by the distance from the Pad and the height from the ground. The temperature difference between Pad and Fan was about 8.1$^{\circ}C$~10.4$^{\circ}C$ without shading and about 4.4$^{\circ}C$~5.5$^{\circ}C$ with shading.

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Deformation of the floor structure of railway vehicle depending on temperature and humidity (온습도 변화에 따른 철도차량 바닥재의 변형)

  • Shin, Bum-Sik;Kim, Myong-Soo;Choi, Yeon-Sun
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1002-1007
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    • 2008
  • The floor structure of railway vehicle can deflect and warp due to variation of temperature and humidity at the inside and outside of vehicle. In this study, its temperature and humidity characteristics was investigated experimentally for beam and plate specimen and numerically for the floor structure assembly. The temperature and humidity characteristics of a part were measured and the deformation and stress distribution of the floor structure were calculated using a commercial software. And the warp deformation of the plywood was measured experimentally. The results show that the temperature and humidity effects on the floor structure are the important factor to decide the strength and the quality of the floor structure of railway vehicles.

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